WorldWideScience

Sample records for absorption air-conditioning system

  1. Monitoring and analysis of an absorption air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Perez de Vinaspre, M.; Bourouis, M.; Coronas, A. [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, Tarragona (Spain); Garcia, A.; Soto, V.; Pinazo, J.M. [E.T.S. Ingenieros Industriales, Valencia (Spain)

    2004-09-01

    In the last few years, high-energy consumption due to air-conditioning has led to a growing interest in the efficient use of energy in buildings. Although simulation programs have always been the main tools for analyzing energy in buildings, the reliability of their results is often compromised by a lack of certainty to reflect real conditions. The aim of this work is to monitorize and analyze the thermal behavior of an absorption-based air-conditioning installation of a university building in Tarragona, Spain. The existing monitoring system of the installation has been improved by implementing additional sensors and flow meters. The data has been stored during summer 2002 and used to assess the energy balance of the air-conditioning installation and the operational regime of the absorption chiller. [Author].

  2. Residential solar air conditioning: Energy and exergy analyses of an ammonia–water absorption cooling system

    International Nuclear Information System (INIS)

    Aman, J.; Ting, D.S.-K.; Henshaw, P.

    2014-01-01

    Large scale heat-driven absorption cooling systems are available in the marketplace for industrial applications but the concept of a solar driven absorption chiller for air-conditioning applications is relatively new. Absorption chillers have a lower efficiency than compression refrigeration systems, when used for small scale applications and this restrains the absorption cooling system from air conditioning applications in residential buildings. The potential of a solar driven ammonia–water absorption chiller for residential air conditioning application is discussed and analyzed in this paper. A thermodynamic model has been developed based on a 10 kW air cooled ammonia–water absorption chiller driven by solar thermal energy. Both energy and exergy analyses have been conducted to evaluate the performance of this residential scale cooling system. The analyses uncovered that the absorber is where the most exergy loss occurs (63%) followed by the generator (13%) and the condenser (11%). Furthermore, the exergy loss of the condenser and absorber greatly increase with temperature, the generator less so, and the exergy loss in the evaporator is the least sensitive to increasing temperature. -- Highlights: • 10 kW solar thermal driven ammonia–water air cooled absorption chiller is investigated. • Energy and exergy analyses have been done to enhance the thermal performance. • Low driving temperature heat sources have been optimized. • The efficiencies of the major components have been evaluated

  3. LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery

    Science.gov (United States)

    Ko, Suk M.

    1980-01-01

    This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

  4. Designing the lithium bromide air conditioning absorption system for a bus

    International Nuclear Information System (INIS)

    Yusoff Ali; Kamaruzzaman Sopian; Hariadi

    2006-01-01

    A system of air-conditioning using Lithium Bromide absorption system is used as an alternative refrigerant that will not pollute the atmosphere. Lithium Bromide is a chemical salt soluble in water. There is a big difference between vapour compression system and LiBr 2 absorption system. The absorption air conditioning system is made of a generator, a condenser, an evaporator and an absorber with necessary pumps and piping. When LiBr 2 solution is heated under low pressure, water will evaporate first, while LiBr 2 will remain in the solution and will become more concentrated. The water is the refrigerant in this system. The generator, where the water is vapourised, is heated using an electric heater or solar energy. The LiBr 2 weak solution under low pressure in the generator is heated and the water evaporate into vapour. The vapour produced is then cooled in the condenser and then expanded into the evaporator. The refrigerant (water) in evaporator change phase from liquid to vapour by absorbing heat from cooling water, which flow in the coil in the evaporator. The chilled water obtained is then pumped into the fan coil, which will be used in conditioning the passenger area of the bus. The water vapour from the evaporator is absorbed into LiBr 2 solution in the absorber, forming a weak solution of LiBr 2 . the weak solution from the absorber is then pumped back to the generator to regenerate. The absorption system does not use compressor, but requires pumps that need lower input power compared to that of a compressor. The system is considered as a new application for the bus. This will have great potential and will be environmentally friendly. The model in this study will be used for calculation of the cooling load for the bus

  5. Open absorption system for cooling and air conditioning using membrane contactors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R.; Dorer, V. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland)

    2008-07-01

    Air conditioning systems based upon the open absorption principle, essentially an absorption device operating at atmospheric pressure, have been proposed and investigated at many instances in the past eighty years. Their potential for improving energy efficiency is clearly recognized in the earliest research reports. By the mid 1950ies, solar thermal energy was being applied to drive open absorption-based air conditioning systems. For several reasons, however, the open absorption technology was not mature enough to take place in the mainstream. In the past two decades, vigorous efforts have been undertaken to reverse this situation, but success continued to elude, despite the fact that the main problems, such as corrosion, aerosols in the supply air, etc., have been identified. This report details the work and the main results from the MemProDEC Project. In this project innovative solutions were proposed, and successfully investigated, for the corrosion problem and the improvement of efficiency of the absorption process, in particular a new method to cool a very compact absorber. The practically uniform flow distribution for all three streams in the absorber (air, water and desiccant) warrants the contact of the air to be dehumidified with the desiccant over the whole surface of exchange (across a porous membrane). This, together with the cooling with water in counter flow to the air, are the key factors for the excellent effectiveness of the absorber. As the results show, the dehydration effectiveness of the prototype absorber is up to 150 % higher than that previously obtained by others. The solutions developed for compactness and modularity represent an important step in the way to flexible manufacturing, i.e. using a single element size to assemble autonomous air handling units of various nominal capacities. And although the manufacturing methods of the individual elements require improvement, namely by avoiding adhesive bonding, the choice of materials and the

  6. Open absorption system for cooling and air conditioning using membrane contactors. 2006 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R. [Materials Science and Technology (EMPA), Abteilung Bautechnologien, Duebendorf (Switzerland)

    2006-11-15

    This illustrated annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of an open absorption system for cooling and air-conditioning. The report reviews the construction of a first prototype and the manufacture of its components. The conceptual design of this new type of air handling unit (AHU), operating with a liquid desiccant, is discussed. The AHU is to be autonomous and the system will not require additional mechanical refrigeration. It is to be thermally driven at temperatures below 80 {sup o}C. Waste heat sources, solar collectors, district heating plants and co-generation systems are targeted as providers of thermal energy at this temperature level. Work carried out is reported on, including that on two-stream membrane contactors.

  7. Application of a solar refrigeration system by absorption for the air conditioning of buildings

    Energy Technology Data Exchange (ETDEWEB)

    Machielsen, Cees H. M [Delft University of Technology, Mekelweg (Netherlands); Hagendijk, Andre E [Consultancy and Research (Netherlands)

    2000-07-01

    This paper describes the Sofri project, a cooperation between Ceeran Ltd and The Delft University of Technology. The main objective of this project is to develop the necessary knowledge and experience to commercialize solar-assisted air conditioning and dehumidification systems in the Dutch Caribbean. The project is motivated by the present needs of the Dutch Caribbean for renewable energy sources and the fact that the Caribbean has a high and uniform insolation throughout the year. Furthermore, hotels and offices in this area use more than 40% of their energy for air-conditioning purposes. Therefore solar-assisted air conditioning systems are a logic approach in reducing the energy demand and to lower the peak electricity reducing the energy demands for the local power station. Ceeran Ltd has the objective to reach full commercialization of the proposed technologies in the Dutch Caribbean. The research is concentrated on liquid absorption machines and solar collection systems such as flat plates with selective surfaces, heat pipe evacuated tubes flat plate collectors, and Compound Parabolic Concentrators. The first demonstration unit is planned to be installed in an office building in Curacao. The installation consists of a 35 kW LiBr/H{sub 2}O absorption machine driven by 100 m{sup 2} flat pate collectors with a gas backup system. The system will provide comfort air-conditioning for this these type of office buildings during daytime. [Spanish] Este documento describe el proyecto SOFRI, una cooperacion entre Ceeran, Ltd, y la Universidad Tecnologica del Delft. El principal objetivo de este proyecto es el de desarrollar el conocimiento necesario y la experiencia para comercializar los sistemas de aire acondicionado y deshumidificacion ayudados por la energia solar en el Caribe Holandes. Este proyecto ha sido motivado por las actuales necesidades del Caribe Holandes de fuentes de energia renovable y por el hecho de que el Caribe tiene una alta y uniforme insolacion

  8. Solar-assisted absorption air-conditioning systems in buildings: Control strategies and operational modes

    International Nuclear Information System (INIS)

    Shirazi, Ali; Pintaldi, Sergio; White, Stephen D.; Morrison, Graham L.; Rosengarten, Gary; Taylor, Robert A.

    2016-01-01

    Highlights: • A simulation model of a solar driven absorption chiller is developed in detail. • Three control strategies were proposed in the solar loop of the plant. • Series and parallel auxiliary heater arrangements were investigated. • The results showed the auxiliary-heater in parallel outperformed the series one. • Solar fraction can be increased by 20% by implementing the proposed configuration. - Abstract: Solar-assisted cooling technology has enormous potential for air-conditioning applications since both solar energy supply and cooling energy demand are well correlated. Unfortunately, market uptake of solar cooling technologies has been slow due to the high capital cost and limited design/operational experience. In the present work, different designs and operational modes for solar heating and cooling (SHC) absorption chiller systems are investigated and compared in order to identify the preferred design strategies for these systems. Three control scenarios are proposed for the solar collector loop. The first uses a constant flow pump, while the second and third control schemes employ a variable speed pump, where the solar collector (SC) set-point temperature could be either fixed or adjusted to the required demand. Series and parallel arrangements, between the auxiliary heater and the storage tank, have been examined in detail from an energy efficiency perspective. A simulation model for different system layouts is developed in the transient system simulation environment (TRNSYS, Version 17). Simulation results revealed that the total solar fraction of the plant is increased by up to 11% when a variable speed solar loop pump is used to achieve a collector set-point temperature adjusted according to the building load demand. Another significant finding of this study is that a parallel configuration for the auxiliary heater out-performs a conventional series configuration. The yearly performance of an auxiliary heater in parallel with the storage

  9. Modelling LiBr-H2O solution concentration/crystallization of low thermal-powered absorption air conditioning system

    International Nuclear Information System (INIS)

    Abdullah, M.O.

    2000-01-01

    A computer model is developed to predict the concentration of lithium bromide - water (LiBr-H 2 O) solution for used in low thermal energy-driven absorption air conditioning plants design. The computer program is capable to alert the users from undesirable solidification or crystallization zones. Good agreements between simulated concentration and experimental data from standard chart/table have been obtained. (Author)

  10. Ventilation-air conditioning system

    International Nuclear Information System (INIS)

    Kubokoya, Takashi.

    1991-01-01

    Heretofore, in ventilation-air conditioning systems in a nuclear power plant, exhaust gases from each of the ventilation-air conditioning systems of a reactor building, a turbine building, a waste processing building are joined and they are released into atmosphere from the top of a high main exhaustion stack. In order to build such a high main exhaustion stack, a considerable construction cost is required and, in addition, there is a worry of lacking balance with surrounding scenery. Then, in the present invention, exhaust gases are heated by waste heat in a turbine during their introduction from the ventilation-air conditioning facility in the building of a power plant to the main exhaust stack. With such a constitution, since the exhaust gases are heated and their temperature is elevated, they uprise by natural convection when they are released from the top of the main exhaustion stack to the atmosphere. Accordingly, they are released to a level higher than the conventional case in view of the volume of the blower which sends the exhaust gases under pressure, to diffuse them to the atmosphere more sufficiently compared with a conventional case. Further, the height of the main exhaustion stack can be reduced, enabling to minimize the cost for moving the blower. (T.M.)

  11. Simulation of an air conditioning absorption refrigeration system in a co-generation process combining a proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pilatowsky, I.; Gamboa, S.A.; Rivera, W. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Romero, R.J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas - UAEM, Cuernavaca, Morelos (Mexico); Isaza, C.A. [Universidad Pontificia Bolivariana, Medellin (Colombia). Instituto de Energia y Termodinamica; Sebastian, P.J. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico); Moreira, J. [Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico)

    2007-10-15

    In this work, a computer simulation program was developed to determine the optimum operating conditions of an air conditioning system during the co-generation process. A 1 kW PEMFC was considered in this study with a chemical/electrical theoretical efficiency of 40% and a thermal efficiency of 30% applying an electrical load of 100%. A refrigeration-absorption cycle (RAC) operating with monomethylamine-water solutions (MMA-WS), with low vapor generation temperatures (up to 80 C) is proposed in this work. The computer simulation was based on the refrigeration production capacity at the maximum power capacity of the PEMFC. Heat losses between the fuel cell and the absorption air conditioning system at standard operating conditions were considered to be negligible. The results showed the feasibility of using PEMFC for cooling, increasing the total efficiency of the fuel cell system. (author)

  12. A comprehensive, multi-objective optimization of solar-powered absorption chiller systems for air-conditioning applications

    International Nuclear Information System (INIS)

    Shirazi, Ali; Taylor, Robert A.; Morrison, Graham L.; White, Stephen D.

    2017-01-01

    Highlights: • Multi-objective optimization of solar single/multi-effect absorption chillers was conducted. • Primary energy consumption and total annual cost were considered as the objectives. • Optimized designs of the alternative configurations were compared. • A detailed sensitivity analysis of the Pareto optimal solutions was investigated. - Abstract: Solar heating and cooling (SHC) systems are currently under rapid development and deployment due to their potential to reduce the use of fossil fuel resources and to alleviate greenhouse gas emissions in the building sector – a sector which is responsible for ∼40% of the world energy use. Absorption chiller technology (traditionally powered by natural gas in large buildings), can easily be retrofitted to run on solar energy. However, numerous non-intuitive design choices must be analyzed to achieve the best techno-economic performance of these systems. To date, there has been little research into the optimal configurations among the long list of potential solar-driven absorption chiller systems. To address this lack of knowledge, this paper presents a systematic simulation-based, multi-objective optimization of three common, commercially available lithium bromide-water absorption chillers – single-effect, double-effect and triple-effect – powered by evacuated tube collectors (ETCs), evacuated flat plate collectors (EFPCs), and concentrating parabolic trough collectors (PTCs), respectively. To the best of authors’ knowledge, this is the first study of its kind that compares the optimized designs of the most promising configurations of solar-assisted absorption chillers against a common set of energy, economic, and environmental metrics from a holistic perspective. A simulation model of these three configurations is developed using TRNSYS 17. A combined energy, economic, and environmental analysis of the modeled systems is conducted to calculate the primary energy use as well as the levelized total

  13. Modeling and numerical simulation of a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage

    Institute of Scientific and Technical Information of China (English)

    QIU Jia; LIANG Jian; CHEN GuangMing; DU RuXu

    2009-01-01

    This paper presents a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage. It solves the problem of unreliable solar energy supply by storing the working fluids and hence, functions 24 h per day. First, the working principles are described and the dynamic models for the primary energy storage components are developed. Then, the system is evaluated based on a numerical simulation. Based on the meteorological data of a typical day in a subtropical area, with the area of a solar collector being set at 19.15 m2, whilst the initial charging mass, mass fraction and temperature of the solution are respectively set at 379.5 kg, 54.16% and 34.5 ℃, it is found that the respective coefficients of performance (COP) of the air conditioning system and the en-tire system (including the solar panel) are 0.7771 and 0.4372. In particular, the energy storage density of the system is 206.69 MJ/m3 which is much greater than those of chilled water or hot water storage systems under comparable conditions. This makes the new system much more compact and efficient. Finally, an automatic control strategy is given to achieve the highest COP when solar energy fluctuates.

  14. Fungal colonization of air-conditioning systems

    Directory of Open Access Journals (Sweden)

    Ljaljević-Grbić Milica

    2008-01-01

    Full Text Available Fungi have been implicated as quantitatively the most important bioaerosol component of indoor air associated with contaminated air-conditioning systems. rarely, indoor fungi may cause human infections, but more commonly allergenic responses ranging from pneumonitis to asthma-like symptoms. From all air conditioner filters analyzed, 16 fungal taxa were isolated and identified. Aspergillus fumigatus causes more lethal infections worldwide than any other mold. Air-conditioning filters that adsorb moisture and volatile organics appear to provide suitable substrates for fungal colonization. It is important to stress that fungal colonization of air-conditioning systems should not be ignored, especially in hospital environments.

  15. Application of solar energy to air conditioning systems

    Science.gov (United States)

    Nash, J. M.; Harstad, A. J.

    1976-01-01

    The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature.

  16. Utilization of Solar Energy for Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Sutikno Juwari Purwo

    2018-01-01

    Full Text Available The purposes of this research are to do a system simulation of air conditioning utilizing solar energy with single effect absorption refrigeration method, analyze the coefficient of performance (COP for each absorbent-refrigerant variable and compare the effectivity of every absorbent-refrigerant variable used. COP is a constant that denotes the effeciency of a refrigeration system, that is ratio of work or useful output to the amount of work or energy input. The higher the number of COP, the more efficient the system is. Absorbent-refrigerant (working fluids variables used in this research depend on its chemical and thermodynamics properties. Steps in this research are including data collection and tabulation from literature and do a simulation of air conditioning system both commercial air conditioning system (using electrical energy and solar energy air conditioning system with Aspen Plus software. Next, run the simulation for each working fluid variables used and calculate the COP for each variable. Subsequently, analyze and compare the effectivity of all variables used from COP value and economical point of view with commercial air conditioning system. From the result of the simulation, can be concluded that solar air conditioning can achieve 98,85 % of energy savings than commercial air conditioning. Furthermore, from the calculation of COP, the highest COP value is achieved by solar conditioning system with LiNO3-NH3 as working fluid where 55% of the composition is the refrigerant and 45% of absorbent.

  17. Air conditioning systems to clean radioactive air

    International Nuclear Information System (INIS)

    Ganz, G.

    1987-01-01

    The author reports a study by the Institutes fuer Klimatechnik and Umweltschutz Giessen that shows that air conditioning systems not only make the atmosphere more comfortable, they also extract dust particles. This cleaning action is also valid for radioactively contaminated air. (G.T.H./Auth.)

  18. Air conditioning for data processing system areas

    Directory of Open Access Journals (Sweden)

    Hernando Camacho García

    1996-09-01

    Full Text Available The appropiate selection of air conditioners for data processing system areas requires the knowledge of the environmental desing conditions, the air conditioning systems succssfully used computer and the cooling loads to handle. This work contains information about a wide variety of systems designed for computer room applications. a complete example of calculation to determine the amount of heat to be removed for satisfactory operation, is also included.

  19. Hybrid Solar-Geothermal Energy Absorption Air-Conditioning System Operating with NaOH-H2O—Las Tres Vírgenes (Baja California Sur), “La Reforma” Case

    OpenAIRE

    Yuridiana Rocio Galindo-Luna; Efraín Gómez-Arias; Rosenberg J. Romero; Eduardo Venegas-Reyes; Moisés Montiel-González; Helene Emmi Karin Unland-Weiss; Pedro Pacheco-Hernández; Antonio González-Fernández; Jorge Díaz-Salgado

    2018-01-01

    Solar and geothermal energies are considered cleaner and more useful energy sources that can be used to avoid the negative environmental impacts caused by burning fossil fuels. Several works have reported air-conditioning systems that use solar energy coupled to geothermal renewable energy as a thermal source. In this study, an Absorption Air-Conditioning System (AACS) used sodium hydroxide-water (NaOH-H2O) instead of lithium bromide-water to reduce the cost. Low enthalpy geothermal heat was ...

  20. Performance advancement of solar air-conditioning through integrated system design for building

    International Nuclear Information System (INIS)

    Fong, K.F.; Lee, C.K.

    2014-01-01

    This study is to advance the energy performance of solar air-conditioning system through appropriate component integration from the absorption refrigeration cycle and proper high-temperature cooling. In the previous studies, the solar absorption air-conditioning using the working pair of water – lithium bromide (H 2 O–LiBr) is found to have prominent primary energy saving than the conventional compression air-conditioning for buildings in the hot-humid climate. In this study, three integration strategies have been generated for solar cooling, namely integrated absorption air-conditioning; integrated absorption-desiccant air-conditioning; and integrated absorption-desiccant air-conditioning for radiant cooling. To realize these ideas, the working pair of ammonia – water (NH 3 –H 2 O) was used in the absorption cycle, rather than H 2 O–LiBr. As such, the evaporator and the condenser can be separate from the absorption refrigeration cycle for the new configuration of various integrated design alternatives. Through dynamic simulation, the year-round primary energy saving of the proposed integration strategies for solar NH 3 –H 2 O absorption air-conditioning systems could be up to 50.6% and 25.5%, as compared to the conventional compression air-conditioning and the basic solar H 2 O–LiBr absorption air-conditioning respectively. Consequently, carbon reduction of building air-conditioning can be achieved more effectively through the integrated system design in the hot and humid cities. - Highlights: • Three integration strategies, IAAU, IADAU and IADAU-RC, are proposed to advance solar air-conditioning. • NH 3 –H 2 O is adopted for absorption refrigeration instead of H 2 O–LiBr. • Separate evaporator and condenser, desiccant cooling and radiant cooling are designed for IADAU-RC. • IADAU-RC can have 50.6% primary energy saving against the conventional air-conditioning

  1. Thermal Environment for Classrooms. Central System Approach to Air Conditioning.

    Science.gov (United States)

    Triechler, Walter W.

    This speech compares the air conditioning requirements of high-rise office buildings with those of large centralized school complexes. A description of one particular air conditioning system provides information about the system's arrangement, functions, performance efficiency, and cost effectiveness. (MLF)

  2. Hybrid Solar-Geothermal Energy Absorption Air-Conditioning System Operating with NaOH-H2O—Las Tres Vírgenes (Baja California Sur, “La Reforma” Case

    Directory of Open Access Journals (Sweden)

    Yuridiana Rocio Galindo-Luna

    2018-05-01

    Full Text Available Solar and geothermal energies are considered cleaner and more useful energy sources that can be used to avoid the negative environmental impacts caused by burning fossil fuels. Several works have reported air-conditioning systems that use solar energy coupled to geothermal renewable energy as a thermal source. In this study, an Absorption Air-Conditioning System (AACS used sodium hydroxide-water (NaOH-H2O instead of lithium bromide-water to reduce the cost. Low enthalpy geothermal heat was derived from two shallow wells, 50 and 55 m deep. These wells are of interest due to the thermal recovery (temperature vs. time of 56.2 °C that was possible at the maximum depth, which can be used for the first stage of the process. These wells were coupled with solar energy as a geothermal energy application for direct uses such as air-conditioning systems. We studied the performance of an absorption cooling system operating with a NaOH-H2O mixture and using a parabolic trough plant coupled with a low enthalpy geothermal heat system as a hybrid heat source, as an alternative process that can help reduce operating costs and carbon dioxide emissions. The numerical heat transfer results showed the maximum convective heat transfer coefficient, as function of fluid velocity, and maximum temperature for a depth higher than 40 m. The results showed that the highest temperatures occur at low fluid velocities of less than or equal to 5.0 m/s. Under these conditions, reaching temperatures between 51.0 and 56.2 °C in the well was possible, which is required of the geothermal energy for the solar energy process. A water stream was used as the working fluid in the parabolic trough collector field. During the evaluation stage, the average experimental storage tank temperature achieved by the parabolic trough plant was 93.8 °C on October 23 and 92.9 °C on October 25, 2017. The numerical simulation used to evaluate the performance of the absorption cycle used a generator

  3. Air conditioning system with supplemental ice storing and cooling capacity

    Science.gov (United States)

    Weng, Kuo-Lianq; Weng, Kuo-Liang

    1998-01-01

    The present air conditioning system with ice storing and cooling capacity can generate and store ice in its pipe assembly or in an ice storage tank particularly equipped for the system, depending on the type of the air conditioning system. The system is characterized in particular in that ice can be produced and stored in the air conditioning system whereby the time of supplying cooled air can be effectively extended with the merit that the operation cycle of the on and off of the compressor can be prolonged, extending the operation lifespan of the compressor in one aspect. In another aspect, ice production and storage in great amount can be performed in an off-peak period of the electrical power consumption and the stored ice can be utilized in the peak period of the power consumption so as to provide supplemental cooling capacity for the compressor of the air conditioning system whereby the shift of peak and off-peak power consumption can be effected with ease. The present air conditioning system can lower the installation expense for an ice-storing air conditioning system and can also be applied to an old conventional air conditioning system.

  4. A review on the recent development of solar absorption and vapour compression based hybrid air conditioning with low temperature storage

    Directory of Open Access Journals (Sweden)

    Noor D. N.

    2016-01-01

    Full Text Available Conventional air conditioners or vapour compression systems are main contributors to energy consumption in modern buildings. There are common environmental issues emanating from vapour compression system such as greenhouse gas emission and heat wastage. These problems can be reduced by adaptation of solar energy components to vapour compression system. However, intermittence input of daily solar radiation was the main issue of solar energy system. This paper presents the recent studies on hybrid air conditioning system. In addition, the basic vapour compression system and components involved in the solar air conditioning system are discussed. Introduction of low temperature storage can be an interactive solution and improved economically which portray different modes of operating strategies. Yet, very few studies have examined on optimal operating strategies of the hybrid system. Finally, the findings of this review will help suggest optimization of solar absorption and vapour compression based hybrid air conditioning system for future work while considering both economic and environmental factors.

  5. Computer Model to Estimate Reliability Engineering for Air Conditioning Systems

    International Nuclear Information System (INIS)

    Afrah Al-Bossly, A.; El-Berry, A.; El-Berry, A.

    2012-01-01

    Reliability engineering is used to predict the performance and optimize design and maintenance of air conditioning systems. Air conditioning systems are expose to a number of failures. The failures of an air conditioner such as turn on, loss of air conditioner cooling capacity, reduced air conditioning output temperatures, loss of cool air supply and loss of air flow entirely can be due to a variety of problems with one or more components of an air conditioner or air conditioning system. Forecasting for system failure rates are very important for maintenance. This paper focused on the reliability of the air conditioning systems. Statistical distributions that were commonly applied in reliability settings: the standard (2 parameter) Weibull and Gamma distributions. After distributions parameters had been estimated, reliability estimations and predictions were used for evaluations. To evaluate good operating condition in a building, the reliability of the air conditioning system that supplies conditioned air to the several The company's departments. This air conditioning system is divided into two, namely the main chilled water system and the ten air handling systems that serves the ten departments. In a chilled-water system the air conditioner cools water down to 40-45 degree F (4-7 degree C). The chilled water is distributed throughout the building in a piping system and connected to air condition cooling units wherever needed. Data analysis has been done with support a computer aided reliability software, this is due to the Weibull and Gamma distributions indicated that the reliability for the systems equal to 86.012% and 77.7% respectively. A comparison between the two important families of distribution functions, namely, the Weibull and Gamma families was studied. It was found that Weibull method performed for decision making.

  6. A RADIANT AIR-CONDITIONING SYSTEM USING SOLAR-DRIVEN

    Directory of Open Access Journals (Sweden)

    S. A. ABDALLA

    2006-12-01

    Full Text Available Every air-conditioning system needs some fresh air to provide adequate ventilation air required to remove moisture, gases like ammonia and hydrogen sulphide, disease organisms, and heat from occupied spaces. However, natural ventilation is difficult to control because urban areas outside air is often polluted and cannot be supplied to inner spaces before being filtered. Besides the high electrical demand of refrigerant compression units used by most air-conditioning systems, and fans used to transport the cool air through the thermal distribution system draw a significant amount of electrical energy in comparison with electrical energy used by the building thermal conditioning systems. Part of this electricity heats the cooled air; thereby add to the internal thermal cooling peak load. In addition, refrigerant compression has both direct and indirect negative effects on the environment on both local and global scales. In seeking for innovative air-conditioning systems that maintain and improve indoor air quality under potentially more demanding performance criteria without increasing environmental impact, this paper presents radiant air-conditioning system which uses a solar-driven liquid desiccant evaporative cooler. The paper describes the proposed solar-driven liquid desiccant evaporative cooling system and the method used for investigating its performance in providing cold water for a radiant air-conditioning system in Khartoum (Central Sudan. The results of the investigation show that the system can operate in humid as well as dry climates and that employing such a system reduces air-conditioning peak electrical demands as compared to vapour compression systems.

  7. Potential Evaluation of Solar Heat Assisted Desiccant Hybrid Air Conditioning System

    Science.gov (United States)

    Tran, Thien Nha; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao

    The solar thermal driven desiccant dehumidification-absorption cooling hybrid system has superior advantage in hot-humid climate regions. The reasonable air processing of desiccant hybrid air conditioning system and the utility of clean and free energy make the system environment friendly and energy efficient. The study investigates the performance of the desiccant dehumidification air conditioning systems with solar thermal assistant. The investigation is performed for three cases which are combinations of solar thermal and absorption cooling systems with different heat supply temperature levels. Two solar thermal systems are used in the study: the flat plate collector (FPC) and the vacuum tube with compound parabolic concentrator (CPC). The single-effect and high energy efficient double-, triple-effect LiBr-water absorption cooling cycles are considered for cooling systems. COP of desiccant hybrid air conditioning systems are determined. The evaluation of these systems is subsequently performed. The single effect absorption cooling cycle combined with the flat plate collector solar system is found to be the most energy efficient air conditioning system.

  8. Design of energy efficient ventilation and air-conditioning systems

    CERN Document Server

    Seppänen, Olli; Bertilsson, Thore; Maripuu, Mari-Liis; Lamy, Hervé; Vanden Borre, Alex

    2012-01-01

    This guidebook covers numerous system components of ventilation and air-conditioning systems and shows how they can be improved by applying the latest technology products. Special attention is paid to details, which are often overlooked in the daily design practice, resulting in poor performance of high quality products once they are installed in the building system.

  9. Step response and frequency response of an air conditioning system

    NARCIS (Netherlands)

    Crommelin, R.D.; Jackman, P.J.

    1978-01-01

    A system of induction units of an existing air conditioning system has been analyzed with respect to its dynamic properties. Time constants were calculated and measured by analogue models. Comparison with measurements at the installation itself showed a reasonable agreement. Frequency responses were

  10. Model development for air conditioning system in heavy duty trucks

    NARCIS (Netherlands)

    Kessels, J.T.B.A.; van den Bosch, P.P.J.; Zhang, Quansheng; Li, Shengbo Eben; Deng, Kun

    2016-01-01

    This chapter presents a modelling approach for the air conditioning (AC) system in heavy duty trucks. The presented model entails two major elements: a mechanical compressor model and a thermal AC model. The compressor model describes the massflow of the refrigerant as well as the mechanical power

  11. Small photovoltaic setup for the air conditioning system

    Science.gov (United States)

    Masiukiewicz, Maciej

    2017-10-01

    The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES). The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV) to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system). Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

  12. Small photovoltaic setup for the air conditioning system

    Directory of Open Access Journals (Sweden)

    Masiukiewicz Maciej

    2017-01-01

    Full Text Available The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES. The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system. Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

  13. Development of Fuzzy Logic Control for Vehicle Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Henry Nasution

    2008-08-01

    Full Text Available A vehicle air conditioning system is experimentally investigated. Measurements were taken during the experimental period at a time interval of one minute for a set point temperature of 22, 23 and 24oC with internal heat loads of 0, 1 and 2 kW. The cabin temperature and the speed of the compressor were varied and the performance of the system, energy consumption and energy saving ware analyzed. The main objective of the experimental work is to evaluate the energy saving obtained when the fuzzy logic control (FLC algorithm, through an inverter, continuously regulates the compressor speed. It demonstrates better control of the compressor operation in terms of energy consumption as compared to the control by using a thermostat imposing On/Off cycles on the compressor at the nominal frequency of 50 Hz. The experimental set-up consists of original components from the air conditioning system of a compact passenger vehicle. The experimental results indicate that the proposed technique can save energy and improve indoor comfort significantly for vehicle air conditioning systems compared to the conventional (On/Off control technique.

  14. Sensory evaluation of heating and air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Evin, F.; Siekierski, E. [Electricite de France, Research and Development Division, Les Renardieres, Moret Sur Loing (France)

    2002-07-01

    Existing standards and models, such as ISO 7730 or the work of Fanger [Thermal Comfort], are not sufficient to characterise the satisfaction and pleasantness of end-users provided by heating or air conditioning systems. For this reason Electricite de France (EDF) has initiated a project with the aim of using sensory evaluation techniques in the design of HVAC systems. Sensory evaluation has been used for more than 30 years in the food industry, and now involves the cosmetics, the phone and the automotive industries. It is based on a dual evaluation: sensation measurements carried out by a small panel of trained expert assessors; preference studies performed by a large panel of representative consumers. A correlation between the data of both studies is then used to explain the preferences in terms of sensations (preference mapping). The first experiments performed in 1999 and 2000 have provided lists of descriptors of thermal sensation and acoustic sensation associated with heating and air conditioning appliances. They show that it is possible to define discriminative descriptors, to train a panel and to reliably quantify these descriptors. It is then possible to draw the sensory profiles of different heating, ventilation and air conditioning (HVAC) systems. The future experimental laboratory that EDF has decided to build is also presented, where the trained panels and end-users will evaluate the sensations and the preferences of real systems in eight 'realistic environmental chambers' designed, furnished and decorated like offices and flats. (author)

  15. Liquid over-feeding air conditioning system and method

    Science.gov (United States)

    Mei, Viung C.; Chen, Fang C.

    1993-01-01

    A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant.

  16. Simulation of Artificial Intelligence for Automotive Air-conditioning System

    Institute of Scientific and Technical Information of China (English)

    YUAN Xiao-mei; CHEN You-hua; CHEN Zhi-jiu

    2002-01-01

    The artificial intelligence is applied to the simulation of the automotive air-conditioning system ( AACS )According to the system's characteristics a model of AACS, based on neural network, is developed. Different control methods of AACS are discussed through simulation based on this model. The result shows that the neural- fuzzy control is the best one compared with the on-off control and conventional fuzzy control method.It can make the compartment's temperature descend rapidly to the designed temperature and the fluctuation is small.

  17. Liquid over-feeding air conditioning system and method

    Science.gov (United States)

    Mei, V.C.; Chen, F.C.

    1993-09-21

    A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant. 1 figure.

  18. Analysis on a hybrid desiccant air-conditioning system

    International Nuclear Information System (INIS)

    Jia, C.X.; Dai, Y.J.; Wu, J.Y.; Wang, R.Z.

    2006-01-01

    Hybrid desiccant-assisted preconditioner and split cooling coil system, which combines the merits of moisture removal by desiccant and cooling coil for sensible heat removal, is a potential alternative to conventional vapor compression cooling systems. In this paper, experiments on a hybrid desiccant air-conditioning system, which is actually an integration of a rotary solid desiccant dehumidification and a vapor compression air-conditioning unit, had been carried out. It is found that, compared with the conventional VC (vapor compression) system, the hybrid desiccant cooling system economizes 37.5% electricity powers when the process air temperature and relative humidity are maintained at 30 o C, and 55% respectively. The reason why the hybrid desiccant cooling system features better performance relative to the VC system lies in the improvement brought about in the performance of the evaporator in VC unit due to desiccant dehumidification. A thermodynamic model of the hybrid desiccant system with R-22 as the refrigerant has been developed and the impact of operating parameters on the sensible heat ratio of the evaporator and the electric power saving rate has been analyzed. It is found that a majority of evaporators can operate in the dry condition even if the regeneration temperature is lower (i.e. 80 o C)

  19. Performance enhancement of a subcooled cold storage air conditioning system

    International Nuclear Information System (INIS)

    Hsiao, M.-J.; Cheng, C.-H.; Huang, M.-C.; Chen, S.-L.

    2009-01-01

    This article experimentally investigates the enhancement of thermal performance for an air conditioning system utilizing a cold storage unit as a subcooler. The cold storage unit is composed of an energy storage tank, liquid-side heat exchanger, suction-side heat exchanger and energy storage material (ESM), water. When the cooling load is lower than the nominal cooling capacity of the system, the cold storage unit can store extra cold energy of the system to subcool the condenser outlet refrigerant. Hence, both the cooling capacity and coefficient of performance (COP) of the system will be increased. This experiment tests the two operation modes: subcooled mode with energy storage and non-subcooled mode without energy storage. The results show that for fixed cooling loads at 3.05 kW, 3.5 kW and 3.95 kW, the COP of the subcooled mode are 16.0%, 15.6% and 14.1% higher than those of the non-subcooled mode, respectively. In the varied cooling load experiments, the COP of the subcooled cold storage air conditioning system is 15.3% higher than the conventional system.

  20. [Air quality control systems: heating, ventilating, and air conditioning (HVAC)].

    Science.gov (United States)

    Bellucci Sessa, R; Riccio, G

    2004-01-01

    After a brief illustration of the principal layout schemes of Heating, Ventilating, and Air Conditioning (HVAC), the first part of this paper summarizes the standards, both voluntary and compulsory, regulating HVAC facilities design and installation with regard to the question of Indoor Air Quality (IAQ). The paper then examines the problem of ventilation systems maintenance and the essential hygienistic requirements in whose absence HVAC facilities may become a risk factor for people working or living in the building. Lastly, the paper deals with HVAC design strategies and methods, which aim not only to satisfy comfort and air quality requirements, but also to ensure easy and effective maintenance procedures.

  1. Thermo economical evaluation of retrofitting strategies in air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Tribess, Arlindo; Fiorelli, Flavio Augusto Sanzogo; Hernandez Neto, Alberto [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia Mecanica]. E-mail: atribess@usp.br; fiorelli@usp.br; ahneto@usp.br

    2000-07-01

    In a building project, several subsystems are designed, among them the air conditioning system. Electrical energy consumption profiles show that this subsystem is responsible for 40 to 50% of total consumption in a commercial building. Besides the study of technical aspects that should be considered in order to assure the thermal comfort of the occupants as well the temperature and humidity conditions for an efficient equipment operation, an economical evaluation of this subsystem should be also made. In retrofit projects, the economical aspect is also critical for such projects in order to assure bigger efficiency in an economically attractive way. This paper analyses some strategies that might be adopted in retrofitting an air conditioning system installed in a commercial building with mixed occupation. By mixed we mean that some floors have a typical office occupation profile and other floors are mainly occupied by electronic equipment. This analysis includes both technical and economical evaluation. The proposed solutions performance are compared to the old system, which allows to verify the retrofitting impact in energy consumption reduction and its economical feasibility. (author)

  2. Research on ration selection of mixed absorbent solution for membrane air-conditioning system

    International Nuclear Information System (INIS)

    Li, Xiu-Wei; Zhang, Xiao-Song; Wang, Fang; Zhao, Xiao; Zhang, Zhuo

    2015-01-01

    Highlights: • We derive models of the membrane air-conditioning system with mixed absorbents. • We make analysis on system COP, cost-effectiveness and economy. • The paper provides a new method for ideal absorbent selection. • The solutes concentration of 50% achieves the best cost-effectiveness and the economy. - Abstract: Absorption air-conditioning system is a good alternative to vapor compression system for developing low carbon society. To improve the performance of the traditional absorption system, the membrane air-conditioning system is configured and its COP can reach as high as 6. Mixed absorbents are potential for cost reduction of the membrane system while maintaining a high COP. On the purpose of finding ideal mixed absorbent groups, this paper makes analysis on COP, cost-effectiveness and economy of the membrane system with mixed LiBr–CaCl 2 absorbent solution. The models of the system have been developed for the analysis. The results show the COP is higher for the absorbent groups with lower concentration of the total solute and higher concentration ratio of LiBr. It also reveals when the total solutes concentration is about 50%, it achieves the best cost-effectiveness and the economy. The process of the analysis provides a useful method for mixed absorbents selection

  3. Production and exploitation of thermoelectric air conditioning systems for vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Dudnik, Vladimir [Conditioner Ltd, Gagarin (Russian Federation); Skipidarov, Sergey [SCTB NORD, Moskau (Russian Federation); Rapp, Axel [Quick-Ohm Kupper und Co. GmbH, Wuppertal-Cronenberg (Germany)

    2011-07-01

    In the paper more than 10-year experience of thermoelectric devices batch manufacturing is described for the field of their obvious advantages. This field of application includes thermoelectric air conditioning systems which have shown their competitive advantage when used in vehicles of elevated vibration where compressor equipment application is difficult because of leakage of refrigerant. Energy characteristics of air conditioners for tractors, excavators, tanks, locomotive driver's cabins and cranes are described. Thermoelectric (TE) air conditioners mechanical test data as well as operation experience in vehicles are presented. It is shown that consumption of tellurium, which is a strategic component for thermoelectric materials manufacturing, may be lowered to 40 grams per 1 kW of cooling. (orig.)

  4. Solar driven air conditioning and refrigeration systems corresponding to various heating source temperatures

    International Nuclear Information System (INIS)

    Wang, R.Z.; Xu, Z.Y.; Pan, Q.W.; Du, S.; Xia, Z.Z.

    2016-01-01

    Highlights: • Modular silica gel–water adsorption chiller was designed and tested. • Single/double effect LiBr–water absorption chiller was operated and tested. • 1.n effect LiBr–water absorption chiller was proposed, designed and tested. • CaCl_2/AC–ammonia adsorption refrigerator was introduced and tested. • NH_3–H_2O absorption ice maker with better internal heat recovery was introduced. - Abstract: Solar driven air conditioning systems can cope with solar collectors working in a wide range of temperatures. Sorption systems, including absorption and adsorption refrigeration systems, are among the best choices for solar cooling. Five systems including modular silica gel–water adsorption chiller, single/double effect LiBr–water absorption chiller, 1.n effect LiBr–water absorption chiller, CaCl_2/AC (activated carbon)–ammonia adsorption refrigerator, and the water–ammonia absorption ice maker with better internal heat recovery were presented. The above five sorption chillers/refrigerators work under various driven temperatures and fulfill different refrigeration demands. The thermodynamic design and system development of the systems were shown. All these systems have improvements in comparison with existing systems and may offer good options for high efficient solar cooling in the near future.

  5. Thermoeconomic evaluation of air conditioning system with chilled water storage

    International Nuclear Information System (INIS)

    Lin, Hu; Li, Xin-hong; Cheng, Peng-sheng; Xu, Bu-gong

    2014-01-01

    Highlights: • A new thermoeconomic evaluation methodology has been presented. • The relationship between thermodynamic and economic performances has been revealed. • A key point for thermal storage technology further application is discovered. • A system has been analyzed via the new method and EUD method. - Abstract: As a good load shifting technology for power grid, chilled energy storage has been paid more and more attention, but it always consumes more energy than traditional air conditioning system, and the performance analysis is mostly from the viewpoint of peak-valley power price to get cost saving. The paper presents a thermoeconomic evaluation methodology for the system with chilled energy storage, by which thermodynamic performance influence on cost saving has been revealed. And a system with chilled storage has been analyzed, which can save more than 15% of power cost with no energy consumption increment, and just certain difference between peak and valley power prices can make the technology for good economic application. The results show that difference between peak and valley power prices is not the only factor on economic performance, thermodynamic performance of the storage system is the more important factor, and too big price difference is a barrier for its application, instead of for more cost saving. All of these give a new direction for thermal storage technology application

  6. Uncertainty Evaluation of Residential Central Air-conditioning Test System

    Science.gov (United States)

    Li, Haoxue

    2018-04-01

    According to national standards, property tests of air-conditioning are required. However, test results could be influenced by the precision of apparatus or measure errors. Therefore, uncertainty evaluation of property tests should be conducted. In this paper, the uncertainties are calculated on the property tests of Xinfei13.6 kW residential central air-conditioning. The evaluation result shows that the property tests are credible.

  7. Energy Analysis for Air Conditioning System Using Fuzzy Logic Control

    Directory of Open Access Journals (Sweden)

    Henry Nasution

    2011-04-01

    Full Text Available Reducing energy consumption and to ensure thermal comfort are two important considerations for the designing an air conditioning system. An alternative approach to reduce energy consumption proposed in this study is to use a variable speed compressor. The control strategy will be proposed using the fuzzy logic controller (FLC. FLC was developed to imitate the performance of human expert operators by encoding their knowledge in the form of linguistic rules. The system is installed on a thermal environmental room with a data acquisition system to monitor the temperature of the room, coefficient of performance (COP, energy consumption and energy saving. The measurements taken during the two hour experimental periods at 5-minutes interval times for temperature setpoints of 20oC, 22oC and 24oC with internal heat loads 0, 500, 700 and 1000 W. The experimental results indicate that the proposed technique can save energy in comparison with On/Off and proportional-integral-derivative (PID control.

  8. Research on Heat Exchange Process in Aircraft Air Conditioning System

    Science.gov (United States)

    Chichindaev, A. V.

    2017-11-01

    Using of heat-exchanger-condenser in the air conditioning system of the airplane Tu-204 (Boeing, Airbus, Superjet 100, MS-21, etc.) for cooling the compressed air by the cold air with negative temperature exiting the turbine results in a number of operational problems. Mainly it’s frosting of the heat exchange surface, which is the cause of live-section channels frosting, resistance increasing and airflow in the system decreasing. The purpose of this work is to analyse the known freeze-up-fighting methods for heat-exchanger-condenser, description of the features of anti-icing protection and offering solutions to this problem. For the problem of optimizing the design of heat exchangers in this work used generalized criterion that describes the ratio of thermal resistances of cold and hot sections, which include: the ratio of the initial values of heat transfer agents flow state; heat exchange surface finning coefficients; factors which describes the ratio of operating parameters and finning area. By controlling the ratio of the thermal resistances can be obtained the desired temperature of the heat exchange surface, which would prevent freezing. The work presents the results of a numerical study of the effect of different combinations of regime and geometrical factors changes on reduction of the heat-exchanger-condenser freezing surface area, including using of variable ratio of thermal resistances.

  9. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System.

    Science.gov (United States)

    Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

    2015-11-16

    In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18-22 g/m³ to a range of 13.5-18.3 g/m³. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  10. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Baiwang Zhao

    2015-11-01

    Full Text Available In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18–22 g/m3 to a range of 13.5–18.3 g/m3. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  11. Air-cooled LiBr-water absorption chillers for solar air conditioning in extremely hot weathers

    International Nuclear Information System (INIS)

    Kim, D.S.; Infante Ferreira, C.A.

    2009-01-01

    A low temperature-driven absorption cycle is theoretically investigated for the development of an air-cooled LiBr-water absorption chiller to be combined with low-cost flat solar collectors for solar air conditioning in hot and dry regions. The cycle works with dilute LiBr-water solutions so that risk of LiBr crystallization is less than for commercially available water-cooled LiBr-water absorption chillers even in extremely hot ambient conditions. Two-phase heat exchangers in the system were modelled taking account of the heat and mass transfer resistances in falling film flows by applying the film theory in thermal and concentration boundary layers. Both directly and indirectly air-cooled chillers were modelled by properly combining component models and boundary conditions in a matrix system and solved with an algebraic equation solver. Simulation results predict that the chillers would deliver chilled water around 7.0 deg. C with a COP of 0.37 from 90 deg. C hot water under 35 deg. C ambient condition. At 50 deg. C ambient temperature, the chillers retained about 36% of their cooling power at 35 deg. C ambient. Compared with the directly air-cooled chiller, the indirectly air-cooled chiller presented a cooling power performance reduction of about 30%

  12. Sphingomonas frigidaeris sp. nov., isolated from an air conditioning system.

    Science.gov (United States)

    Lee, Yunho; Jeon, Che Ok

    2017-10-01

    A strictly aerobic Gram-stain-negative bacterium, designated strain KER25-10 T , was isolated from a laboratory air conditioning system in South Korea. Cells were yellow-pigmented, non-motile rods showing catalase- and oxidase-positive reactions. The strain grew at pH 4.0-9.0 (optimum, pH 6.0-7.0) and 10-40 °C (optimum, 30 °C) and in the presence of 0-3 % (w/v) NaCl (optimum, 0 %). The G+C content of the genomic DNA was 65.1 mol%. Strain KER25-10 T contained ubiquinone-10 (Q-10) as the predominant isoprenoid quinone and C16 : 0, C17 : 1ω6c, summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c) as the major fatty acids. The major polar lipids were sphingoglycolipid, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. Only spermidine was detected as the polyamine. Phylogenetic analysis based on 16S rRNA sequences indicated that strain KER25-10 T formed a distinct phylogenetic lineage within the genus Sphingomonas of the family Sphingomonadaceae and the strain was most closely related to Sphingomonas kyeonggiense THG-DT81 T with a 96.8 % 16S rRNA gene sequence similarity. On the basis of phenotypic, chemotaxonomic and molecular features, strain KER25-10 T clearly represents a novel species of the genus Sphingomonas, for which the name Sphingomonas frigidaeris sp. nov. is proposed. The type strain is KER25-10 T (=KACC 19285 T =JCM 32053 T ).

  13. Analysis and simulation of mobile air conditioning system coupled with engine cooling system

    International Nuclear Information System (INIS)

    Qi, Zhao-gang; Chen, Jiang-ping; Chen, Zhi-jiu

    2007-01-01

    Many components of the mobile air conditioning system and engine cooling system are closely interrelated and make up the vehicle climate control system. In the present paper, a vehicle climate control system model including air conditioning system and engine cooling system has been proposed under different operational conditions. All the components have been modeled on the basis of experimental data. Based on the commercial software, a computer simulation procedure of the vehicle climate control system has been developed. The performance of the vehicle climate control system is simulated, and the calculational data have good agreement with experimental data. Furthermore, the vehicle climate control simulation results have been compared with an individual air conditioning system and engine cooling system. The influences between the mobile air conditioning system and the engine cooling system are discussed

  14. Research on mass transfer and actual performance of the membrane regeneration air-conditioning system

    International Nuclear Information System (INIS)

    Li, Xiu-Wei; Zhang, Xiao-Song; Chen, Qing

    2015-01-01

    Highlights: • Experimental research has been made on the membrane air-conditioning system. • We develop mass transfer models for the membrane regeneration process. • The paper exposes the actual performance of the system. • Increase of membrane pairs improves the performance. - Abstract: Absorption air-conditioning system has great advantages in energy conservation and environmental protection. To improve the performance of the traditional system, the membrane regeneration absorption system was proposed. Its COP could approach 6 by regenerating absorbent solution with the ion exchange membranes. However, the theoretical conclusion has not been supported by the experiment. This paper presents the experimental research of the membrane regeneration process. It has investigated the mass transfer process, energy efficiency and actual performance under different working conditions. Based on that, a mass transfer model has been developed and the influences of some key parameters have been exposed. It found the regeneration performance is mainly influenced by the current intensity. The calculation results with the model agree well the experimental data. The actual efficiency was lower than 50%, caused by energy loss in heat and electrochemical reactions. The actual COP is between 1 and 3, lower current intensity and more membrane pairs could improve it.

  15. Air conditioning systems as non-infectious health hazards inducing acute respiratory symptoms.

    Science.gov (United States)

    Gerber, Alexander; Fischer, Axel; Willig, Karl-Heinz; Groneberg, David A

    2006-04-01

    Chronic and acute exposure to toxic aerosols belongs to frequent causes of airway diseases. However, asthma attacks due to long-distance inhalative exposure to organic solvents, transmitted via an air condition system, have not been reported so far. The present case illustrates the possibility of air conditioning systems as non-infectious health hazards in occupational medicine. So far, only infectious diseases such as legionella pneumophila pneumonia have commonly been associated to air-conditioning exposures but physicians should be alert to the potential of transmission of toxic volatile substances via air conditioning systems. In view of the events of the 11th of September 2001 with a growing danger of large building terrorism which may even use air conditioning systems to transmit toxins, facility management security staff should be alerted to possible non-infectious toxic health hazards arising from air-conditioning systems.

  16. Francisella guangzhouensis sp. nov., isolated from air-conditioning systems.

    Science.gov (United States)

    Qu, Ping-Hua; Chen, Shou-Yi; Scholz, Holger C; Busse, Hans-Jürgen; Gu, Quan; Kämpfer, Peter; Foster, Jeffrey T; Glaeser, Stefanie P; Chen, Cha; Yang, Zhi-Chong

    2013-10-01

    Four strains (08HL01032(T), 09HG994, 10HP82-6 and 10HL1960) were isolated from water of air-conditioning systems of various cooling towers in Guangzhou city, China. Cells were Gram-stain-negative coccobacilli without flagella, catalase-positive and oxidase-negative, showing no reduction of nitrate, no hydrolysis of urea and no production of H2S. Growth was characteristically enhanced in the presence of l-cysteine, which was consistent with the properties of members of the genus Francisella. The quinone system was composed of ubiquinone Q-8 with minor amounts of Q-9. The polar lipid profile consisted of the predominant lipids phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, two unidentified phospholipids (PL2, PL3), an unidentified aminophospholipid and an unidentified glycolipid (GL2). The polyamine pattern consisted of the major compounds spermidine, cadaverine and spermine. The major cellular fatty acids were C10 : 0, C14 : 0, C16 : 0, C18 : 1ω9c and C18 : 1 3-OH. A draft whole-genome sequence of the proposed type strain 08HL01032(T) was generated. Comparative sequence analysis of the complete 16S and 23S rRNA genes confirmed affiliation to the genus Francisella, with 95 % sequence identity to the closest relatives in the database, the type strains of Francisella philomiragia and Francisella noatunensis subsp. orientalis. Full-length deduced amino acid sequences of various housekeeping genes, recA, gyrB, groEL, dnaK, rpoA, rpoB, rpoD, rpoH, fopA and sdhA, exhibited similarities of 67-92 % to strains of other species of the genus Francisella. Strains 08HL01032(T), 09HG994, 10HP82-6 and 10HL1960 exhibited highly similar pan-genome PCR profiles. Both the phenotypic and molecular data support the conclusion that the four strains belong to the genus Francisella but exhibit considerable divergence from all recognized Francisella species. Therefore, we propose the name Francisella guangzhouensis sp

  17. Methylobacterium frigidaeris sp. nov., isolated from an air conditioning system.

    Science.gov (United States)

    Lee, Yunho; Jeon, Che Ok

    2018-01-01

    A reddish pink-pigmented, Gram-stain-negative, aerobic and methylotrophic bacterial strain, designated strain IER25-16 T , was isolated from a laboratory air conditioning system in the Republic of Korea. Cells were motile rods showing catalase- and oxidase-positive reactions. Strain IER25-16 T grew at 10-40 °C (optimum, 30 °C), at pH 4.0-7.0 (optimum, pH 5.0-7.0) and in the presence of 0-1.0 % (w/v) NaCl (optimum, 0 %). The major respiratory quinone was ubiquinone-10 and ubiquinone-9 was also detected as the minor respiratory quinone. Summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c) was detected as the predominant fatty acids. The genomic DNA G+C content of strain IER25-16 T was 70.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain IER25-16 T belonged to the genus Methylobacterium of the class Alphaproteobacteria. Strain IER25-16 T was most closely related to Methylobacterium platani PMB02 T (97.9 %), Methylobacterium aquaticum GR16 T (97.9 %) and Methylobacterium tarhaniae N4211 T (97.5 %). The average nucleotide identity and in silico DNA-DNA hybridization values between strain IER25-16 T and M. platani, M. aquaticum and M. tarhaniae were 88.3, 88.8 and 89.6 % and 36.2, 37.3 and 39.3 %, respectively. The phenotypic and chemotaxonomic features and the phylogenetic inference clearly suggested that strain IER25-16 T represents a novel species of the genus Methylobacterium, for which the name Methylobacteriumfrigidaeris sp. nov. is proposed. The type strain is strain IER25-16 T (=KACC 19280 T =JCM 32048 T ).

  18. DESIGN OF WATER-COOLED PACKAGED AIR-CONDITIONING SYSTEMS BASED ON RELIABILITY ASSESSMENT

    OpenAIRE

    関口, 圭輔; 中尾, 正喜; 藁谷, 至誠; 植草, 常雄; 羽山, 広文

    2007-01-01

    Water-cooled packaged air-conditioning systems are reevaluated in terms of alleviating the heat island phenomenon in cities and effectively utilizing building rooftops. Up to now, such reliability assessment has been insufficient, and this has limited the use of this kind of air-conditioning system in the information and communications sectors that demand a high reliability. This work has led to the development of a model for evaluating the reliability of water-cooled package air-conditioning...

  19. An expert fault diagnosis system for vehicle air conditioning product development

    NARCIS (Netherlands)

    Tan, C.F.; Tee, B.T.; Khalil, S.N.; Chen, W.; Rauterberg, G.W.M.

    2015-01-01

    The paper describes the development of the vehicle air-conditioning fault diagnosis system in automotive industries with expert system shell. The main aim of the research is to diagnose the problem of new vehicle air-conditioning system development process and select the most suitable solution to

  20. Combined desalination and solar-assisted air-conditioning system

    International Nuclear Information System (INIS)

    Gude, Veera Gnaneswar; Nirmalakhandan, Nagamany

    2008-01-01

    Analysis of a new desalination process utilizing low grade thermal energy is presented. In this process, fresh water is distilled from saline water under near-vacuum pressures created by passive means, enabling low-temperature distillation with lower energy requirements. The energy for low-temperature distillation is provided by a thermal energy storage (TES) system maintained at 55 deg. C utilizing any low grade waste heat source. In this study, heat rejected by the condenser of a modified absorption refrigeration system (ARS) is evaluated as a possible source to drive this desalination process. The energy for the generator of the ARS is provided by a combination of solar collector system and grid power. Results of this study show that the thermal energy rejected by an ARS of cooling capacity of 3.25 kW (0.975 tons of refrigeration) along with an additional energy input of 208 kJ/kg of desalinated water is adequate to produce desalinated water at an average rate of 4.5 kg/h. This energy consumption is competitive with that of the multi-stage flash distillation process of similar capacity (338 kJ/kg). An integrated process model and performance curves of the proposed approach are presented in this paper. Effects of process parameters on the performance of the system are also presented

  1. Project of air conditioning system by absorption of water-lithium bromide using solar energy and simulation of its operation under several conditions; Projeto de sistema para condicionamento de ar por absorcao de agua-brometo de litio utilizando energia solar e simulacao de sua operacao sob condicoes diversas

    Energy Technology Data Exchange (ETDEWEB)

    Sbravati, Alan; Figueiredo, Jose Ricardo [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mails: alan@fem.unicamp.br; jrfigue@fem.unicamp.br

    2000-07-01

    This article presents computational models for water - lithium bromide absorption air conditioning systems, verifying the use of solar energy as source of heat for the cycle. Four different models were elaborated for the cycle, changing the configurations and hypotheses. In each model two algorithms were elaborated: the first one accomplished the calculations of the heat and mass flows and a estimative of the areas heat transfer, a project of a system, and another which, based on the answers of the first, simulate the behavior of this system when the conditions of initial project are changed, keeping constant the constructive parameters. As in the project a numeric procedure has been used for solution of non lineal systems based on the algorithm of Newton-Raphson. The main alteration among the models went to substitution of the expansion device and evaporator, and, in the fourth model, was increased a procedure for calculation of the solar collector performance. (author)

  2. Thermodynamic analysis of the two-phase ejector air-conditioning system for buses

    International Nuclear Information System (INIS)

    Ünal, Şaban; Yilmaz, Tuncay

    2015-01-01

    Air-conditioning compressors of the buses are usually operated with the power taken from the engine of the buses. Therefore, an improvement in the air-conditioning system will reduce the fuel consumption of the buses. The improvement in the coefficient of performance (COP) of the air-conditioning system can be provided by using the two-phase ejector as an expansion valve in the air-conditioning system. In this study, the thermodynamic analysis of bus air-conditioning system enhanced with a two-phase ejector and two evaporators is performed. Thermodynamic analysis is made assuming that the mixing process in ejector occurs at constant cross-sectional area and constant pressure. The increase rate in the COP with respect to conventional system is analyzed in terms of the subcooling, condenser and evaporator temperatures. The analysis shows that COP improvement of the system by using the two phase ejector as an expansion device is 15% depending on design parameters of the existing bus air-conditioning system. - Highlights: • Thermodynamic analysis of the two-phase ejector refrigeration system. • Analysis of the COP increase rate of bus air-conditioning system. • Analysis of the entrainment ratio of the two-phase ejector refrigeration system

  3. Ventilation and air-conditioning system for PWR nuclear power plant

    International Nuclear Information System (INIS)

    Ohmoto, Kenji

    1987-01-01

    This report outlines the ventilation and air conditioning facilities for PWR nuclear power plant as well as design re-evaluation and optimization of ventilation and air-conditioning. The primary PWR installations are generally housed in the nuclear reactor building, auxiliary buildings and control building, which are equipped with their own ventilation and air-conditioning systems to serve for their specific purposes. A ventilation/air-conditioning system should be able to work effectively not only for maintaining the ordinary reactor operation but also for controlling the environmental temperature in the event of an accident. Designing of a ventilation/air-conditioning system relied on empirical data in the past, but currently it is performed based on information obtained from various analyses to optimize the system configuration and ventilation capacity. Design re-evaluation of ventilation/air-conditioning systems are conducted widely in various areas, aiming at the integration of safety systems, optimum combination of air-cooling and water-cooling systems, and optimization of the ventilation rate for controlling the concentrations of radioactive substances in the atmosphere in the facilities. It is pointed out that performance evaluation of ventilation/air-conditioning systems, which has been conducted rather macroscopically, should be carried out more in detal in the future to determine optimum air streams and temperature distribution. (Nogami, K.)

  4. Heating, Ventilation and Air-Conditioning Systems, Part of Indoor Air Quality Design Tools for Schools

    Science.gov (United States)

    The main purposes of a Heating, Ventilation, and Air-Conditioning system are to help maintain good indoor air quality through adequate ventilation with filtration and provide thermal comfort. HVAC systems are among the largest energy consumers in schools.

  5. [Microbial air purity in hospitals. Operating theatres with air conditioning system].

    Science.gov (United States)

    Krogulski, Adam; Szczotko, Maciej

    2010-01-01

    The aim of this study was to show the influence of air conditioning control for microbial contamination of air inside the operating theatres equipped with correctly working air-conditioning system. This work was based on the results of bacteria and fungi concentration in hospital air obtained since 2001. Assays of microbial air purity conducted on atmospheric air in parallel with indoor air demonstrated that air filters applied in air-conditioning systems worked correctly in every case. To show the problem of fluctuation of bacteria concentration more precisely, every sequences of single results from successive measure series were examined independently.

  6. Performance of desiccant air conditioning system with geothermal energy under different climatic conditions

    International Nuclear Information System (INIS)

    El-Agouz, S.A.; Kabeel, A.E.

    2014-01-01

    Highlights: • The performance of the hybrid air conditioning system is studied. • The influence of important operating parameters are estimated. • The ventilation, makeup and mix cycles are investigated at different climate. • The highest COP of the hybrid air conditioning system is 1.03. • The hybrid system provides a human thermal comfort at different climates. - Abstract: Energy saving still and continue a major seek in our life, due to the continuous increase in energy consumptions. So, a desiccant air conditioning system with geothermal energy is conducted in the current study. The thermal analysis of air conditioning system with its different components desiccant wheel, solar collector, heat exchanger, ground heat exchanger and water spray evaporative cooler is presented. Three different air conditioning cycles are simulated in the current study for different zones like: hot-dry zone, warm-dry zone, hot-humid zone and the warm-humid zone. The results show that the desiccant air conditioning system successfully provides a better thermal comfort condition in different climates. This hybrid system significantly decreases the supplied air temperature from 12.7 to 21.7 °C at different climate zones. When ω in , air and T Reg increasing, COP decreases and the ventilation cycle provides the better COP. The highest COP value of the desiccant air conditioning system is about 1.03 while the lowest value is about 0.15. The SHR of makeup cycle is higher than that ventilation cycle at warm and hot-humid zone and vice versa at warm and hot-dry zone. The highest SHR value of the desiccant air conditioning system is about 0.99 while the lowest value is about 0.2. The T sup,air , ω sup,air , COP and SHR isolines may easily be used for pre-evaluating of various cooling cycles in different climates. The hybrid system provides a human thermal comfort at different climates

  7. Transitioning to Low-GWP Alternatives in Motor Vehicle Air Conditioning Systems

    Science.gov (United States)

    This fact sheet provides information on low-GWP alternatives in newly manufactured motor vehicle air conditioning systems. It discusses HFC alternatives, market trends, challenges to market entry for alternatives, and potential solutions.

  8. A simulation Model of the Reactor Hall Ventilation and air Conditioning Systems of ETRR-2

    International Nuclear Information System (INIS)

    Abd El-Rahman, M.F.

    2004-01-01

    Although the conceptual design for any system differs from one designer to another. each of them aims to achieve the function of the system required. the ventilation and air conditioning system of reactors hall is one of those systems that really differs but always dose its function for which it is designed. thus, ventilation and air conditioning in some reactor hall constitute only one system whereas in some other ones, they are separate systems. the Egypt Research Reactor-2 (ETRR-2)represents the second type. most studies conducted on ventilation and air conditioning simulation models either in traditional building or for research rectors show that those models were not designed similarly to the model of the hall of ETRR-2 in which ventilation and air conditioning constitute two separate systems.besides, those studies experimented on ventilation and air conditioning simulation models of reactor building predict the temperature and humidity inside these buildings at certain outside condition and it is difficult to predict when the outside conditions are changed . also those studies do not discuss the influences of reactor power changes. therefore, the present work deals with a computational study backed by infield experimental measurements of the performance of the ventilation and air conditioning systems of reactor hall during normal operation at different outside conditions as well as at different levels of reactor power

  9. Ice Storage Air-Conditioning System Simulation with Dynamic Electricity Pricing: A Demand Response Study

    Directory of Open Access Journals (Sweden)

    Chi-Chun Lo

    2016-02-01

    Full Text Available This paper presents an optimal dispatch model of an ice storage air-conditioning system for participants to quickly and accurately perform energy saving and demand response, and to avoid the over contact with electricity price peak. The schedule planning for an ice storage air-conditioning system of demand response is mainly to transfer energy consumption from the peak load to the partial-peak or off-peak load. Least Squares Regression (LSR is used to obtain the polynomial function for the cooling capacity and the cost of power consumption with a real ice storage air-conditioning system. Based on the dynamic electricity pricing, the requirements of cooling loads, and all technical constraints, the dispatch model of the ice-storage air-conditioning system is formulated to minimize the operation cost. The Improved Ripple Bee Swarm Optimization (IRBSO algorithm is proposed to solve the dispatch model of the ice storage air-conditioning system in a daily schedule on summer. Simulation results indicate that reasonable solutions provide a practical and flexible framework allowing the demand response of ice storage air-conditioning systems to demonstrate the optimization of its energy savings and operational efficiency and offering greater energy efficiency.

  10. Instrumentation of air conditioning and ventilation system - R-5 project

    International Nuclear Information System (INIS)

    Kulkarni, P.B.; Naik, C.D.; Narasingha Rao, S.N.

    1977-01-01

    A detailed account of instrumentation proposed for airconditioning and ventilation system in the R-5, 100 MW thermal research reactor, under construction is presented. Controls and instrumentation provided in this system are electronic, pneumatic and hydraulic in nature depending on the application. They cater to the accurate operation of the system and maintain the conditions strictly within desired tolerances. (S.K.K.)

  11. Intelligent energy management control of vehicle air conditioning system coupled with engine

    International Nuclear Information System (INIS)

    Khayyam, Hamid; Abawajy, Jemal; Jazar, Reza N.

    2012-01-01

    Vehicle Air Conditioning (AC) systems consist of an engine powered compressor activated by an electrical clutch. The AC system imposes an extra load to the vehicle's engine increasing the vehicle fuel consumption and emissions. Energy management control of the vehicle air conditioning is a nonlinear dynamic system, influenced by uncertain disturbances. In addition, the vehicle energy management control system interacts with different complex systems, such as engine, air conditioning system, environment, and driver, to deliver fuel consumption improvements. In this paper, we describe the energy management control of vehicle AC system coupled with vehicle engine through an intelligent control design. The Intelligent Energy Management Control (IEMC) system presented in this paper includes an intelligent algorithm which uses five exterior units and three integrated fuzzy controllers to produce desirable internal temperature and air quality, improved fuel consumption, low emission, and smooth driving. The three fuzzy controllers include: (i) a fuzzy cruise controller to adapt vehicle cruise speed via prediction of the road ahead using a Look-Ahead system, (ii) a fuzzy air conditioning controller to produce desirable temperature and air quality inside vehicle cabin room via a road information system, and (iii) a fuzzy engine controller to generate the required engine torque to move the vehicle smoothly on the road. We optimised the integrated operation of the air conditioning and the engine under various driving patterns and performed three simulations. Results show that the proposed IEMC system developed based on Fuzzy Air Conditioning Controller with Look-Ahead (FAC-LA) method is a more efficient controller for vehicle air conditioning system than the previously developed Coordinated Energy Management Systems (CEMS). - Highlights: ► AC interacts: vehicle, environment, driver components, and the interrelationships between them. ► Intelligent AC algorithm which uses

  12. Feasibility study of using agriculture waste as desiccant for air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Khedari, J.; Rawangkul, R.; Hirunlabh, J. [King Mongkut' s University of Technology Thonburi, Bangkok (Thailand). Buidling Scientific Research Center; Chimchavee, W. [University of Thai Chamber of Commerce, Bangkok (Thailand); Watanasungsuit, A. [South East Asia Univ., Bangkok (Thailand). Engineering Management

    2003-08-01

    This research was aimed at investigating the feasibility of using dried agricultural waste as desiccant for an open cycle air conditioning system. The natural fibers are, therefore, intended to replace chemical desiccant such as silica gel, molecular sieves etc. The investigation was limited to Coconut coir (Cocos nucifera) and Durian peels (Durio zibethinus). Experimental results confirmed that dry coconut coir and durian peel can absorb 30 g and 17 g H{sub 2}O per 100 g dry product, respectively, from air at the average condition of 32{sup o}C and 75% relative humidity. The optimum airflow rate is about 84 and 98 m{sup 3}/hr-100 g dry product, respectively. Therefore, the dry coconut coir is more suitable than the dry durian peel. Comparison between the dry coconut coir and silica gel showed that the average adsorption rate of coconut coir is less than that of silica gel by about 5 g/h-100 g dry product at an airflow rate of 84 m{sup 3}/h and 60 min operating time. However, it is still an interesting option to replace silica gel in open cycle air conditioning system, as the decrease of average adsorption rate is rather small. The other extremely interesting advantage of coconut coir is that during moisture absorption the heat generated during the process is less important. That means the air leaves the coconut coir bed at a lower temperature compared to that with a silica gel. Therefore, the saving of cooling energy is much more important. (Author)

  13. The application of gas ejector for road transport air conditioning system

    Science.gov (United States)

    Sumeru, Nasution, Henry; Ani, Farid Nasir

    2012-06-01

    The depletion of fossil fuel supply requires fuel and energy saving in energy utilization system. Therefore, these required the development of new and efficient technologies as to reduce fuel consumption especially in air conditioning of road vehicles. Currently, the air conditioning for road vehicles uses vapor compression system. Although the vapor compression system has high COP, the compressor is driven by vehicle engines, which take additional fuel consumption when the air conditioning system is in operation. In this study, the waste heat of radiator drives the ejector refrigeration for air conditioning. Although the ejector refrigeration system has low COP, the use of heat driven air conditioning will reduce the fuel consumption as compared with conventional system. This is because the systems do not use the mechanical engine load. The analysis of this study is based on the ejector refrigeration system using natural refrigerant (isobutene). The evaporation temperature is 10°C, condensation temperature is 35°C, generator temperature is 90°C with ejector isentropic efficiency of 0.7, and the COP system is 0.25. The heat released by the radiator of typical small road vehicles is between 60 to 100 kW and if the generator absorbs 20% of the heat, the heat contained in the generator is 12 to 20 kW. When the ejector air conditioning system has a COP 0.25, it will generate cooling capacity between 3 to 5 kW, compared with the conventional air conditioning of similar vehicles, which is approximately 2 to 4.4 kW.

  14. Studi Eksperimental Pengontrolan Air Conditioning System Dengan Fuzzy Logic Control

    Directory of Open Access Journals (Sweden)

    Sudirman -

    2012-11-01

    Full Text Available Electrical energy available in Indonesia at this time is not yet sufficient for all existing activities, this can be proved byfrequent occurrence of blackouts in several areas in Indonesia. It is necessary for a saving in electrical energy consumptionin all sectors, it is one of the refrigeration system. Research was conducted by testing AC (3 HP / 3 phase using 2 differentcontrol systems, namely conventional control and FLC. Testing is done by placing the indoor units in cold storage room.Each test performed with varying load in the test room, ie no light burden, lamp 1000 Watt, and lamp 2000 Watt. Testingusing a conventional control system set point temperature 26 ° C and 3 variations of the differential is 1 , 2 and 3 , the FLCusing the temperature setting point 26 ° C. From this research we can conclude that the application of FLC system produceselectric energy consumption of the lowest compared to conventional control in this case is the differential 1. FLC applicationof electrical energy consumption at load 1000 Watt lower 11% and the load 2000 Watt 4% lower compared withconventional control in diffrensial 1.

  15. The system of thermoelectric air conditioning based on permeable thermoelements

    Directory of Open Access Journals (Sweden)

    Cherkez R. G.

    2009-04-01

    Full Text Available There is thermoelectric air conditioner unit on the basis of permeable cooling thermoelements presented. In thermoelectric air conditioner unit the thermoelectric effects and the Joule–Thomson effect have been used for the air stream cooling. There have been described the method of temperature distribution analysis, the determinations of energy conversion power characteristics and design style of permeable thermoelement with maximum coefficient of performance described. The results of computer analysis concerning the application of the thermoelement legs material on the basis of Bi2Te3 have shown the possibility of coefficient of performance increase by a factor of 1,6—1,7 as compared with conventional thermoelectric systems.

  16. Modeling validation and control analysis for controlled temperature and humidity of air conditioning system.

    Science.gov (United States)

    Lee, Jing-Nang; Lin, Tsung-Min; Chen, Chien-Chih

    2014-01-01

    This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14 °C, 0006 kg(w)/kg(da) in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system.

  17. Modeling Validation and Control Analysis for Controlled Temperature and Humidity of Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Jing-Nang Lee

    2014-01-01

    Full Text Available This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14°C, 0006 kgw/kgda in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system.

  18. Air-conditioning and ventilation systems and components of nuclear facilities

    International Nuclear Information System (INIS)

    2006-01-01

    The Guide defines the requirements for the design, implementation and operation of the air-conditioning and ventilation systems of nuclear facilities belonging to safety classes 3 and 4, and for the related documents to be submitted to STUK (Radiation and Nuclear Safety Authority, Finland). Furthermore, the Guide describes the inspections of air-conditioning and ventilation systems to be conducted by STUK during construction and operation of the facilities. As far as systems and components belonging to safety class 2 are concerned, STUK sets additional requirements case by case. In general, air-conditioning systems refer to systems designed to manage the indoor air cleanness, temperature, humidity and movement. In some rooms of a nuclear power plant, ventilation systems are also used to prevent radioactive materials from spreading outside the rooms. Guide YVL1.0 defines the safety principles concerning the air-conditioning and ventilation of nuclear power plants. Guide YVL2.0 gives the requirements for the design of nuclear power plant systems. In addition, YVLGuide groups 3, 4, 5 and 7 deal with the requirements for air-conditioning and ventilation systems with regard to the mechanical equipment, fire prevention, electrical systems, instrumentation and control technology, and the restriction of releases. The rules and regulations issued by the Ministry of the Environment and the Ministry of the Interior (RakMK, the Finnish building code) concerning the design and operation of air-conditioning and ventilation systems and the related fire protection design bases also apply to nuclear facilities. Exhaust gas treatment systems, condenser vacuum systems of boiling water reactor plants and leak collection systems are excluded from the scope of this Guide

  19. Does the air condition system in busses spread allergic fungi into driver space?

    Science.gov (United States)

    Sowiak, Małgorzata; Kozajda, Anna; Jeżak, Karolina; Szadkowska-Stańczyk, Irena

    2018-02-01

    The aim of this study was to establish whether the air-conditioning system in buses constitutes an additional source of indoor air contamination with fungi, and whether or not the fungi concentration depends on the period from the last disinfection of the system, combined with replacement of the cabin dust particle filter. The air samples to fungi analysis using impact method were taken in 30 buses (20 with an air-conditioning system, ACS; 10 with a ventilation system, VS) in two series: 1 and 22 weeks after cabin filter replacement and disinfection of the air-conditioning system. During one test in each bus were taken two samples: before the air-conditioning or ventilation system switched on and 6 min after operating of these systems. The atmospheric air was the external background (EB). After 1 week of use of the system, the fungi concentrations before starting of the ACS and VS system were 527.8 and 1053.0 cfu/m 3 , respectively, and after 22 weeks the concentrations were 351.9 and 1069.6 cfu/m 3 , respectively. While in the sample after 6 min of ACS and VS system operating, the fungi concentration after 1 week of use was 127.6 and 233.7 cfu/m 3 , respectively, and after 22 weeks it was 113.3 and 324.9 cfu/m 3 , respectively. Results do not provide strong evidence that air-conditioning system is an additional source of indoor air contamination with fungi. A longer operation of the system promoted increase of fungi concentration in air-conditioned buses only.

  20. Evaluation of Rankine cycle air conditioning system hardware by computer simulation

    Science.gov (United States)

    Healey, H. M.; Clark, D.

    1978-01-01

    A computer program for simulating the performance of a variety of solar powered Rankine cycle air conditioning system components (RCACS) has been developed. The computer program models actual equipment by developing performance maps from manufacturers data and is capable of simulating off-design operation of the RCACS components. The program designed to be a subroutine of the Marshall Space Flight Center (MSFC) Solar Energy System Analysis Computer Program 'SOLRAD', is a complete package suitable for use by an occasional computer user in developing performance maps of heating, ventilation and air conditioning components.

  1. Ice thermal storage air conditioning system for electric load leveling; Denryoku heijunka to hyochikunetsu system

    Energy Technology Data Exchange (ETDEWEB)

    Shigenaga, Y. [Daikin Industries Ltd., Osaka (Japan)

    1998-08-15

    Thermal storage air conditioning system is the one to use energy stored into thermal storing materials by using night electric power and to operate effective air conditioning. Therefore, as load can be treated by the stored energy, volume of the apparatus can be reduced. And, by reduction of the consumed power at day time, it can contribute to leveling of electric power demand. In general, there are two types in the thermal storage method: one is a method to store as thermal energy, and the other is that to store as chemical energy. For conditions required for the storing materials, important elements on their actual uses are not only physical properties such as large thermal storage per unit and easy thermal in- and out-puts, but also safety, long-term reliability, and easy receiving and economics containing future. The ice thermal storage air conditioning system is classified at the viewpoint of type of ice, kind of thermal storing medium, melting method on using cooling and heating, kinds of thermal medium on cooling and heating. 3 refs., 5 figs., 2 tabs.

  2. Energy managemant through PCM based thermal storage system for building air-conditioning: Tidel Park, Chennai

    International Nuclear Information System (INIS)

    Nallusamy, N.; Sampath, S.; Velraj, R.

    2006-01-01

    Many modern building are designed for air-conditioning and the amount of electrical energy required for providing air-conditioning can be very significant especially in the tropics. Conservation of energy is major concern to improve the overall efficiency of the system. Integration is energy storage with the conventional system gives a lot of potential for energy saving and long-term economics. Thermal energy storage systems can improve energy management and help in matching supply and demand patterns. In the present work, a detailed study has been done on the existing thermal energy storage system used in the air-conditioning system in Tidel Park, Chennai. The present study focuses on the cool energy storage system. The modes of operation and advantages of such a system for energy management are highlighted. The reason for the adoption of combined storage system and the size of the storage medium in the air-conditioning plant are analyzed. The possibility of using this concept in other cooling and heating applications, such as storage type solar water heating system, has been explored

  3. Experimental investigation of a novel configuration of desiccant based evaporative air conditioning system

    International Nuclear Information System (INIS)

    Uçkan, İrfan; Yılmaz, Tuncay; Hürdoğan, Ertaç; Büyükalaca, Orhan

    2013-01-01

    Highlights: ► A novel desiccant based evaporative cooling system is developed and tested. ► Cooling capacity, COP and energy consumption of the system are evaluated. ► Indoor air conditions are in the range of thermal comfort zone and expanded comfort zone. ► Designing of the system have considerable effect on the energy consumption. - Abstract: A novel configuration of desiccant based evaporative cooling system for air conditioning application is developed and tested. At the beginning of the design stage of the system, an analysis is carried out in order to maximize the performance of the system. It is found based on configuration that outdoor air must be used for regeneration to increase performance of the system and so three air channels are used. Experiments are carried out to investigate the total performance of the system and performance of the components used during summer season in a hot and humid climate. Effectiveness values for both heat exchangers and evaporative coolers are calculated through this work. In addition to the cooling capacity, coefficient of performance (COP) and energy consumption of the system are also evaluated. Results show that the effectiveness for the heat exchangers and evaporative coolers are very high under different outdoor conditions. It is also shown from the results that indoor air conditions are in the range of thermal comfort zone defined by ASHRAE and expanded comfort zone for evaporative air conditioning applications.

  4. Experimental Study on Intelligent Control Scheme for Fan Coil Air-Conditioning System

    Directory of Open Access Journals (Sweden)

    Yanfeng Li

    2013-01-01

    Full Text Available An intelligent control scheme for fan coil air-conditioning systems has been put forward in order to overcome the shortcomings of the traditional proportion-integral-derivative (PID control scheme. These shortcomings include the inability of anti-interference and large inertia. An intelligent control test rig of fan coil air-conditioning system has been built, and MATLAB/Simulink dynamics simulation software has been adopted to implement the intelligent control scheme. A software for data exchange has been developed to combine the intelligence control system and the building automation (BA system. Experimental tests have been conducted to investigate the effectiveness of different control schemes including the traditional PID control, fuzzy control, and fuzzy-PID control for fan coil air-conditioning system. The effects of control schemes have been compared and analyzed in robustness, static and dynamic character, and economy. The results have shown that the developed data exchange interface software can induce the intelligent control scheme of the BA system more effectively. Among the proposed control strategies, fuzzy-PID control scheme which has the advantages of both traditional PID and fuzzy schemes is the optimal control scheme for the fan coil air-conditioning system.

  5. Energy savings potential of a hybrid desiccant dehumidification air conditioning system in Beirut

    International Nuclear Information System (INIS)

    Ghali, Kamel

    2008-01-01

    In this work, the transient performance of a hybrid desiccant vapor compression air conditioning system is numerically simulated for the ambient conditions of Beirut. The main feature of this hybrid system is that the regenerative heat needed by the desiccant wheel is partly supplied by the condenser dissipated heat while the rest is supplied by an auxiliary gas heater. The hybrid air conditioning system of the present study replaces a 23 kW vapor compression unit for a typical office in Beirut characterized by a high latent load. The vapor compression subsystem size in the hybrid air conditioning system is reduced to 15 kW at the peak load when the regeneration temperature was fixed at 75 deg. C. Also the sensible heat ratio of the combined hybrid system increased from 0.47 to 0.73. Based on hour by hour simulation studies for a wide range of recorded ambient conditions of Beirut city, this paper predicts the annual energy consumption of the hybrid system in comparison with the conventional vapor compression system for the entire cooling season. The annual running costs savings for the hybrid system is 418.39 USD for a gas cost price of 0.141 USD/kg. The pay back period of the hybrid system is less than five years when the initial cost of the hybrid air conditioning system priced an additional 1712.00 USD. Hence, for a 20-year life cycle, the life cycle savings of the hybrid air conditioning system are 4295.19 USD

  6. Performance evaluation of an integrated automotive air conditioning and heat pump system

    International Nuclear Information System (INIS)

    Hosoz, M.; Direk, M.

    2006-01-01

    This study deals with the performance characteristics of an R134a automotive air conditioning system capable of operating as an air-to-air heat pump using ambient air as a heat source. For this aim, an experimental analysis has been performed on a plant made up of original components from an automobile air conditioning system and some extra equipment employed to operate the system in the reverse direction. The system has been tested in the air conditioning and heat pump modes by varying the compressor speed and air temperatures at the inlets of the indoor and outdoor coils. Evaluation of the data gathered in steady state test runs has shown the effects of the operating conditions on the capacity, coefficient of performance, compressor discharge temperature and the rate of exergy destroyed by each component of the system for both operation modes. It has been observed that the heat pump operation provides adequate heating only in mild weather conditions, and the heating capacity drops sharply with decreasing outdoor temperature. However, compared with the air conditioning operation, the heat pump operation usually yields a higher coefficient of performance and a lower rate of exergy destruction per unit capacity. It is also possible to improve the heating mode performance of the system by redesigning the indoor coil, using another refrigerant with a higher heat rejection rate in the condenser and employing a better heat source such as the engine coolant or exhaust gases

  7. Thermal analysis of a direct evaporative cooling system enhancement with desiccant dehumidification for vehicular air conditioning

    International Nuclear Information System (INIS)

    Alahmer, Ali

    2016-01-01

    Highlights: • Thermal analysis was conducted to design a desiccant evaporative cooling system for vehicular air conditioning. • EC is more efficient than the conventional air conditioning when the gasoline price is more than 0.34 $/liter. • Drawbacks of evaporative cooler of increased weight and reduced COP. • A rotary desiccant dehumidifier with generation was combined with evaporative cooling to be more efficient. - Abstract: This manuscript analyzes the sub-systems of evaporative cooler (EC) combined with desiccant dehumidification and regeneration for automotive air conditioning purpose. The thermodynamic and psychometric analysis was conducted to design all evaporative cooling system components in terms of desiccant selection, regeneration process, compact heat exchanger and evaporative cooler. Moreover, the effect of the desiccant, heat exchanger and evaporative performances on the mass flow rate and water sprayed required for evaporative cooling system was investigated. The results show that the theoretical evaporative cooling design will achieve two main objectives: lower fuel consumption and less environmental pollutants. However, it has the two drawbacks in terms of increased weight and reduces the coefficient of performance (COP). The main remark is that evaporating cooling system is more efficient than the conventional air conditioning when the gasoline price is more than 0.34 $/liter.

  8. Development of residential solar air conditioning system for electricity power peak cut 3

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Gwon Jong [Korea Inst. of Energy and Resources, Daeduk (Korea, Republic of)

    1995-12-31

    In this research, the converter rectifier unit of the inverter air conditioner is substituted into the bidirectional PWM converter. The DC/DC power converter is established on the DC link between the photovoltaic array and the inverter air conditioner, and the photovoltaic air conditioning system which can be parallel driven which utility is developed. (author). 35 ref., 112 figs.

  9. The Evaluation of Unitary & Central Type Air-Conditioning Systems in Selected Florida Schools.

    Science.gov (United States)

    Bradley, William B.

    The study reported here was conducted in an effort to obtain data for comparing the combined owning and operating costs of two different types of air-conditioning systems in two elementary schools. Both schools were built during 1969-70 in the same geographical area along the southeast coast of Florida and are also served by the same electric…

  10. V-TECS Guide for Automobile Air Conditioning and Electrical System Technician.

    Science.gov (United States)

    Meyer, Calvin F.; Benson, Robert T.

    This curriculum guide provides an outline for an eight-unit course to train automobile air conditioning and electrical system technicians. Each unit focuses on a duty that is composed of a number of performance objectives. For each objective, these materials are provided: a task, a standard of performance of task, source of standard, conditions…

  11. Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

    Science.gov (United States)

    Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

    1991-01-01

    Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

  12. The microbiological quality of air improves when using air conditioning systems in cars.

    Science.gov (United States)

    Vonberg, Ralf-Peter; Gastmeier, Petra; Kenneweg, Björn; Holdack-Janssen, Hinrich; Sohr, Dorit; Chaberny, Iris F

    2010-06-01

    Because of better comfort, air conditioning systems are a common feature in automobiles these days. However, its impact on the number of particles and microorganisms inside the vehicle--and by this its impact on the risk of an allergic reaction--is yet unknown. Over a time period of 30 months, the quality of air was investigated in three different types of cars (VW Passat, VW Polo FSI, Seat Alhambra) that were all equipped with a automatic air conditioning system. Operation modes using fresh air from outside the car as well as circulating air from inside the car were examined. The total number of microorganisms and the number of mold spores were measured by impaction in a high flow air sampler. Particles of 0.5 to 5.0 microm diameter were counted by a laser particle counter device. Overall 32 occasions of sampling were performed. The concentration of microorganisms outside the cars was always higher than it was inside the cars. Few minutes after starting the air conditioning system the total number of microorganisms was reduced by 81.7%, the number of mold spores was reduced by 83.3%, and the number of particles was reduced by 87.8%. There were no significant differences neither between the types of cars nor between the types of operation mode of the air conditioning system (fresh air vs. circulating air). All parameters that were looked for in this study improved during utilization of the car's air conditioning system. We believe that the risk of an allergic reaction will be reduced during use also. Nevertheless, we recommend regular maintenance of the system and replacement of older filters after defined changing intervals.

  13. Feasibility of a solar-assisted winter air-conditioning system using evaporative air-coolers

    Energy Technology Data Exchange (ETDEWEB)

    El-Awad, Mohamed M. [Mechanical Engineering Department, the University of Khartoum, P.O. Box 321 Khartoum (Sudan)

    2011-07-01

    The paper presents a winter air-conditioning system which is suitable for regions with mildly cold but dry winters. The system modifies the evaporative air-cooler that is commonly used for summer air-conditioning in such regions by adding a heating process after the humidification process. The paper describes a theoretical model that is used to estimate the system's water and energy consumption. It is shown that a 150-LPD solar heater is adequate for air-conditioning a 500 ft3/min (14.4 m3/min) air flow rate for four hours of operation. The maximum air-flow rate that can be heated by a single solar water-heater for four hours of operation is about 900-cfm, unless a solar water heater large than a 250-LPD heater is used. For the 500 ft3/min air flow rate the paper shows that the 150, 200, 250 and 300 LPD solar water-heaters can provide air-conditioning for 4, 6, 8 and 10 hours, respectively, while consuming less energy than the equivalent refrigerated-type air-conditioner.

  14. Thermodynamic analysis of an innovative liquid desiccant air conditioning system to supply potable water

    International Nuclear Information System (INIS)

    Ahmed, M.A.; Gandhidasan, P.; Zubair, Syed M.; Bahaidarah, Haitham M.

    2017-01-01

    Highlights: • The study objective is to reduce the energy consumption of desiccant AC system. • Heat and mass losses are recovered in the proposed system using a condenser. • The conventional and the proposed systems are compared in terms of COP. • The proposed system performance is better than the conventional system. • The proposed system produces freshwater in addition to space cooling. - Abstract: Liquid desiccant air conditioning systems are cost-effective, environmentally friendly and energy efficient techniques, especially in coastal areas. In the conventional liquid desiccant air conditioning system, the scavenging air is expelled into the atmosphere carrying a considerable amount of energy and water vapor. Thus, there is plenty of room to improve the system performance by recovering these losses. The proposed system consists of a conventional liquid desiccant air conditioning system plus a condenser. The aim of this study is to reduce the energy consumption by recovering the heat from the scavenging air using the condenser while also producing freshwater in addition to space cooling. Lithium chloride (LiCl) is used as the liquid desiccant for this study. The mathematical formulation for simultaneous heat and mass transfer between the condenser and the regenerator was developed to establish a comparison between the performance of the conventional and modified systems. Using the generated model, it is found that the modified system performance is 11.25% better than the conventional system and that it produces 86.4 kg of freshwater per hour as a by-product under the given conditions.

  15. [Biological contamination in office buildings related to ventilation/air conditioning system].

    Science.gov (United States)

    Bródka, Karolina; Sowiak, Małgorzata; Kozajda, Anna; Cyprowski, Marcin; Irena, Szadkowska-Stańczyk

    2012-01-01

    Indoor air is contaminated with microorganisms coming from both the atmospheric air and sources present in premises. The aim of this study was to analyze the concentrations of biological agents in office buildings, dependending on ventilation/air conditioning system and season. The study covered office buildings (different in the system of ventila-tion/air conditioning). Air samples for assessing the levels of inhalable dust, endotoxins and (1-->3)-beta-D-glucans, were taken at the selected stationary points of each building during summer and winter. The air was sampled for 6 h, using portable sets consisting of the GilAir 5 pump and the head filled with a filter of fiber glass. The samples for the presence of airborne bacteria and fungi were collected twice during the day using the impaction method. Average concentrations of inhalable dust, bacteria, fungi, endotoxins and (1-->3)-beta-D-glucans in office premises were 0.09 mg/m3, 6.00 x 10(2) cfu/m3, 4.59 x 10(1) cfu/m3, 0.42 ng/m3 and 3.91 ng/m3, respectively. Higher concentrations of the investigated agents were found in summer. In premises with air conditioning concentrations of airborne fungi, (1-->3)-beta-D-glucans and inhalable dust were significantly lower in winter. In summer the trend was reverse except for (1-->3)-beta-D-glucans. Concentrations of biological agents were affected by the season and the presence of air conditioning. Concentrations of inhalable dust, bacteria, fungi, endotoxins and (1-->3)-beta-D-glucans, observed inside the office buildings, were significantly higher in summer than in winter. The presence of the air conditioning system modified in various ways the levels of biological agents. Its influence was greater on the concentration of fungi and (1-->3)-beta-D-glucans than on that of bacteria and endotoxins.

  16. Potential electricity savings by variable speed control of compressor for air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Nasution, Henry [Bung Hatta University, Department of Mechanical Engineering, Faculty of Industrial Engineering, Padang, West Sumatera (Indonesia); Wan Hassan, Mat Nawi [Universiti Teknologi Malaysia, Faculty of Mechanical Engineering, Skudai, Johor Bahru-Darul Ta' zim (Malaysia)

    2006-05-15

    The potential of a variable-speed compressor running on a controller to provide enhanced load-matching capability, energy saving and thermal comfort for application in air-conditioning system is demonstrated. An air-conditioning system, originally operated on a constant speed mode, is retrofitted with an inverter and a PID controller. The system was installed to a thermal environmental room together with a data acquisition system to monitor energy consumption and temperature of the room. Measurements were taken 2 h daily at a time interval of 5 min for an on/off and an inverter variable-speed conditions. The results indicate that thermal comfort of the room together with energy saving can be obtained through a proper selection of K for the controller. At a temperature setting of 22 C, the energy saving for the system is estimated to reach 25.3% for PID controllers. (orig.)

  17. Management of air-conditioning systems in residential buildings by using fuzzy logic

    Directory of Open Access Journals (Sweden)

    Sohair F. Rezeka

    2015-06-01

    Full Text Available There has been a rising concern in reducing the energy consumption in buildings. Heating, ventilation and air-conditioning system is the biggest consumer of energy in buildings. In this study, management of the air-conditioning system of a building for efficient energy operation and comfortable environment is investigated. The strategy used in this work depends on classifying the rooms to three different groups: very important rooms, important rooms and normal rooms. The total mass flow rate is divided between all rooms by certain percentage using a fuzzy-logic system to get the optimum performance for each room. The suggested Building Management System (BMS was found capable of keeping errors in both temperature and humidity within the acceptable limits at different operating conditions. The BMS can save the chilled/hot water flow rate and the cooling/heating capacity of rooms.

  18. Analysis of an Air Conditioning Coolant Solution for Metal Contamination Using Atomic Absorption Spectroscopy: An Undergraduate Instrumental Analysis Exercise Simulating an Industrial Assignment

    Science.gov (United States)

    Baird, Michael J.

    2004-01-01

    A real-life analytical assignment is presented to students, who had to examine an air conditioning coolant solution for metal contamination using an atomic absorption spectroscopy (AAS). This hands-on access to a real problem exposed the undergraduate students to the mechanism of AAS, and promoted participation in a simulated industrial activity.

  19. Silver zeolite antimicrobial activity in aluminium heating, ventilation and air conditioning system ducts.

    Science.gov (United States)

    Rizzetto, R; Mansi, A; Panatto, D; Rizzitelli, E; Tinteri, C; Sasso, T; Gasparini, R; Crovari, P

    2008-03-01

    Air pollution in confined environments is a serious health problem, in that most people spend long periods indoors (in homes, offices, classrooms etc.). Some people (children, the elderly, heart disease patients, asthmatic or allergic subjects) are at greater risk because of their conditions of frailty. The growing use of air-conditioning systems in many public and private buildings aggravates this health risk, especially when these systems are not correctly installed or regularly serviced. The aim of our study was to verify the capacity of Ag+ ions to stop the growth of bacteria and moulds inside the ducts of Heating, Ventilation and Air Conditioning system ducts (HVAC) systems when these ducts were lined with active Ag+ ions zeolite-coated panels. A Y-shaped HVAC model with two branches was used; one branch was made of traditional galvanized iron, as was the whole system, while the other was lined with active Ag+ zeolite-coated polyurethane panels. During the test, samples of dust present inside both ducts were collected and seeded in liquid and solid media to detect bacteria and moulds. The presence of bacteria was also sought in the air emerging from the outlets of both ducts. Tests made on samples of particulate collected from the two different ducts revealed a lower total bacterial load in the samples collected from the Ag+ zeolite-coated duct than in the samples from the traditional Zn galvanized duct. In addition, the values of bacterial load found in the air emerging from the Ag+ ions zeolite-lined duct were 5 times lower than those found in the air from the traditional galvanized iron duct. The utilization of Ag+ zeolite-coated panels in air-conditioning systems could improve the quality of the emerging air in comparison with traditional installations in galvanized iron. This innovation could prove particularly advantageous in the event of accidents during the installation of air-conditioning systems or of contaminated aerosols coming from outside.

  20. Conceptual Design of Automotive Compressor for Integrated Portable Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Ishak Muhammad Ikman

    2017-01-01

    Full Text Available This study introduces a new concept of portable air conditioner which integrated with some available components in automotive air conditioning system. This new idea intends to solve the storage problems as well as to reduce the price of current portable air conditioner since some devices could directly be used from the automotive air conditioning system. The primary emphasis of this study was on the modification of automotive compressor design so as the system may alternately be operated. The length of conventional compressor shaft is extended to place an additional clutch pulley, a drive plate and a clutch coil. The new concept particularly the shaft and pulley were analysed through slope deflection and computational finite element analyses. The result of engineering analyses exhibited that the new design of compressor shaft and clutch pulleys promote a low risk of failure as the data values recorded are lower than the critical value for each criterion investigated.

  1. Feedback linearization based control of a variable air volume air conditioning system for cooling applications.

    Science.gov (United States)

    Thosar, Archana; Patra, Amit; Bhattacharyya, Souvik

    2008-07-01

    Design of a nonlinear control system for a Variable Air Volume Air Conditioning (VAVAC) plant through feedback linearization is presented in this article. VAVAC systems attempt to reduce building energy consumption while maintaining the primary role of air conditioning. The temperature of the space is maintained at a constant level by establishing a balance between the cooling load generated in the space and the air supply delivered to meet the load. The dynamic model of a VAVAC plant is derived and formulated as a MIMO bilinear system. Feedback linearization is applied for decoupling and linearization of the nonlinear model. Simulation results for a laboratory scale plant are presented to demonstrate the potential of keeping comfort and maintaining energy optimal performance by this methodology. Results obtained with a conventional PI controller and a feedback linearizing controller are compared and the superiority of the proposed approach is clearly established.

  2. Experimental study of a novel capacity control algorithm for a multi-evaporator air conditioning system

    International Nuclear Information System (INIS)

    Xu Xiangguo; Pan Yan; Deng Shiming; Xia Liang; Chan Mingyin

    2013-01-01

    The use of a multi-evaporator air conditioning (MEAC) system is advantageous in terms of installation convenience, high design flexibility, being easy to maintain and commission, better indoor thermal comfort control and higher energy efficiency. While MEAC units worth billions of dollars are sold worldwide, the detailed accounts on compressor capacity control and refrigeration flow distribution amongst evaporators remain unavailable in public domain, mainly due to commercial confidentiality. Limited control algorithms for MEAC systems have been developed based on system simulation, and no experimental-based capacity controller developments and their controllability tests may be identified in open literature. In the study reported in this paper, a novel capacity control algorithm, which imitated On–Off control of a single evaporator air conditioning (A/C) system in each indoor unit of a MEAC system by using variable speed compressor and electronic expansion valves (EEVs), was developed. Controllability tests under various settings for experimentally validating the novel capacity control algorithm were carried out and the control algorithm was further improved based on the experimental results. - Highlights: ► A capacity control algorithm for a multi-evaporator air conditioning system was developed. ► Experimental controllability tests under various settings were carried out. ► The control algorithm was further improved based on the experimental results.

  3. Energy and Greenhouse Gas Emission Assessment of Conventional and Solar Assisted Air Conditioning Systems

    Directory of Open Access Journals (Sweden)

    Xiaofeng Li

    2015-11-01

    Full Text Available Energy consumption in the buildings is responsible for 26% of Australia’s greenhouse gas emissions where cooling typically accounts for over 50% of the total building energy use. The aim of this study was to investigate the potential for reducing the cooling systems’ environmental footprint with applications of alternative renewable energy source. Three types of cooling systems, water cooled, air cooled and a hybrid solar-based air-conditioning system, with a total of six scenarios were designed in this work. The scenarios accounted for the types of power supply to the air-conditioning systems with electricity from the grid and with a solar power from highly integrated building photovoltaics (BIPV. Within and between these scenarios, systems’ energy performances were compared based on energy modelling while the harvesting potential of the renewable energy source was further predicted based on building’s detailed geometrical model. The results showed that renewable energy obtained via BIPV scenario could cover building’s annual electricity consumption for cooling and reduce 140 tonnes of greenhouse gas emissions each year. The hybrid solar air-conditioning system has higher energy efficiency than the air cooled chiller system but lower than the water cooled system.

  4. Characterization of Francisella species isolated from the cooling water of an air conditioning system.

    Science.gov (United States)

    Gu, Quan; Li, Xunde; Qu, Pinghua; Hou, Shuiping; Li, Juntao; Atwill, Edward R; Chen, Shouyi

    2015-01-01

    Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems.

  5. Applications and control of air conditioning systems using rapid cycling to modulate capacity

    Energy Technology Data Exchange (ETDEWEB)

    Poort, M.J.; Bullard, C.W. [Department of Mechanical and Industrial Engineering, Air Conditioning and Refrigeration Center, University of Illinois, 1206 W. Green St., Urbana, IL 61801 (United States)

    2006-08-15

    Rapid cycling the compressor of an air conditioning or refrigeration system can be used to modulate capacity, thus offering an alternative to a variable speed compressor. This paper explores design tradeoffs to optimize rapid cycling performance based on experimental results using two different evaporators and changing other components of an air conditioning system. Rapid cycling has inherent compressor lift penalties associated with larger mass flow rates, which need to be minimized. Preventing dryout (superheating) in the evaporator during the off cycle, a major penalty as cycles are lengthened, is also important. Evaporator dryout is minimized by increasing the refrigerant side area and reducing off cycle drainage. Combining a flash gas bypass with a suction line heat exchanger was found to maximize performance during the off cycle while allowing increased cycle lengths without incurring major penalties. (author)

  6. Filters from taxis air conditioning system: A tool to characterize driver's occupational exposure to bioburden?

    Science.gov (United States)

    Viegas, Carla; Monteiro, Ana; Dos Santos, Mateus; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Quintal Gomes, Anita; Marchand, Geneviève; Lacombe, Nancy; Viegas, Susana

    2018-07-01

    Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony-forming units (CFU) per 1 m 2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole-resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1-31.6%). Seven different azole-resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole-resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based-methods and molecular tools combined enabled an improved risk characterization in this setting. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Exergy analysis of a centralized air conditioning system for ice water

    International Nuclear Information System (INIS)

    Armas, Juan C; Lapido, Margarita J; Castellanos, Juan A

    2006-01-01

    An exergetic analysis of a centralized system of air conditioning, based on a vapor compression refrigeration cycle, appears in this article. The investigation allows to calculate the irreversibilities (exergy destruction) in the main components of the refrigeration cycle as well as to evaluate the sensitivity of this indicator when the operating conditions changes. As main result the most sensible components of the cycle are identified, information that will be useful in order to define strategies of operation focused to the power efficiency increase.

  8. Enthalpy estimation for thermal comfort and energy saving in air conditioning system

    International Nuclear Information System (INIS)

    Chu, C.-M.; Jong, T.-L.

    2008-01-01

    The thermal comfort control of a room must consider not only the thermal comfort level but also energy saving. This paper proposes an enthalpy estimation that is conducive for thermal comfort control and energy saving. The least enthalpy estimator (LEE) combines the concept of human thermal comfort with the theory of enthalpy to predict the load for a suitable setting pair in order to maintain more precisely the thermal comfort level and save energy in the air conditioning system

  9. 'TEWI' concept for estimation of the global warming from the refrigerating and air conditioning systems

    International Nuclear Information System (INIS)

    Ciconkov, Risto

    2002-01-01

    The most applied CFC refrigerants and their HFC alternatives. values of ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) of the most used refrigerants. natural working fluids and their properties. Montreal Protocol and Kyoto Protocol, illogical relations between them concerning to the HFC fluids. Confusion and polemics on the international level about the appliance of HFCs which, by the Kyoto Protocol, are liable to reduction. Introduction of the TEWI concept as a method for estimating the overall influence of refrigerating and air conditioning systems on the greenhouse effect: the direct emission (refrigerant leakage in the atmosphere) and indirect emission as a result of the electrical energy consumption. A demonstration of the TEWI concept on the concrete example in several variants. A discussion about the appliance of the TEWI concept. Meaning of the energy efficiency of the refrigerating systems (indirect CO 2 emission). One of the main measures: prevention of refrigerant leakage (direct CO 2 emission). A need of permanent education and training courses of the people who work on refrigerating and air conditioning systems. A necessity for constitution of an expert body in the country, preparation of a strategy to lay obligations on the new changes of the Kyoto Protocol and news on the world market. Introduction of country regulations, certification of the companies and people involved in refrigeration and air conditioning. (Author)

  10. Air conditioning system and component therefore distributing air flow from opposite directions

    Science.gov (United States)

    Obler, H. D.; Bauer, H. B. (Inventor)

    1974-01-01

    The air conditioning system comprises a plurality of separate air conditioning units coupled to a common supply duct such that air may be introduced into the supply duct in two opposite flow directions. A plurality of outlets such as registers or auxiliary or branch ducts communicate with the supply duct and valve means are disposed in the supply duct at at least some of the outlets for automatically channelling a controllable amount of air from the supply duct to the associated outlet regardless of the direction of air flow within the supply duct. The valve means comprises an automatic air volume control apparatus for distribution within the air supply duct into which air may be introduced from two opposite directions. The apparatus incorporates a freely swinging movable vane in the supply duct to automatically channel into the associated outlet only the deflected air flow which has the higher relative pressure.

  11. Modeling of an Air Conditioning System with Geothermal Heat Pump for a Residential Building

    Directory of Open Access Journals (Sweden)

    Silvia Cocchi

    2013-01-01

    Full Text Available The need to address climate change caused by greenhouse gas emissions attaches great importance to research aimed at using renewable energy. Geothermal energy is an interesting alternative concerning the production of energy for air conditioning of buildings (heating and cooling, through the use of geothermal heat pumps. In this work a model has been developed in order to simulate an air conditioning system with geothermal heat pump. A ground source heat pump (GSHP uses the shallow ground as a source of heat, thus taking advantage of its seasonally moderate temperatures. GSHP must be coupled with geothermal exchangers. The model leads to design optimization of geothermal heat exchangers and to verify the operation of the geothermal plant.

  12. Evaluation of Refrigerating and Air Conditioning Devices in Energy Cascade Systems under the Restriction of Carbon Dioxide Emissions

    Science.gov (United States)

    Shimazaki, Yoichi; Akisawa, Atsushi; Kashiwagi, Takao

    It is necessary to introduce energy cascade systems into the industrial sector in Japan to reduce carbon dioxide emissions. The aim of this study is to evaluate the refrigerating and air conditioning devices in cases of introducing both energy cascade systems and thermal recycling systems in industries located around urban areas. The authors have developed an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Limitation of carbon dioxide emissions results in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature one is shifted to refrigeration. It was found that increasing the amount of garbage combustor waste heat can reduce electric power for the turbo refrigerator by promoting waste heat driven ammonia absorption refrigerator.

  13. Experimental and numerical study of an evaporatively-cooled condenser of air-conditioning systems

    International Nuclear Information System (INIS)

    Islam, M.R.; Jahangeer, K.A.; Chua, K.J.

    2015-01-01

    The performance of an air-conditioning unit with evaporately-cooled condenser coil is studied experimentally and numerically. An experimental setup is fabricated by retrofitting a commercially available air-conditioning unit and installing comprehensive measuring sensors and controllers. Experimental result shows that the COP (Coefficient of Performance) of the evaporately-cooled air-conditioning unit increases by about 28% compared to the conventional air cooled air-conditioning unit. To analyze the heat and mass transfer processes involved in the evaporately-cooled condenser, a detailed theoretical model has been developed based on the fluid flow characteristics of the falling film and the thermodynamic aspect of the evaporation process. Simulated results agree well with experimental data. The numerical model provides new insights into the intrinsic links between operating variables and heat transfer characteristics of water film in evaluating the performance of evaporatively-cooled condenser system. Two heat transfer coefficients, namely, wall to bulk and bulk to interface are introduced and computed from the simulation results under different operating conditions. Finally, the overall heat transfer coefficient for the water film is computed and presented as a function of dimensionless variables which can conveniently be employed by engineers to design and analyze high performance evaporatively-cooled heat exchangers. - Highlights: • Performance of evaporatively-cooled condenser is investigated. • Local convective heat transfer coefficients of water film are determined. • Thermal resistance of water film is negligible. • Heat transfer with evaporated vapor plays significant role on performance. • Better condenser performance translates to an improvement in COP

  14. Performance study of desiccant coated heat exchanger air conditioning system in winter

    International Nuclear Information System (INIS)

    Ge, T.S.; Dai, Y.J.; Wang, R.Z.

    2016-01-01

    Highlights: • Performance of desiccant coated heat exchanger AC system is predicted. • Effects of main operation parameters and climatic conditions are discussed. • Regeneration temperature of 30 °C is recommended under simulation condition. • Higher ambient humidity ratio results in increased humidity ratio of supply air. • Temperature of ambient air has neglectable effect on supply air. - Abstract: Conventional air source heat pump system faces several challenges when adopted in winter season. Solid desiccant air conditioning system can provide humidification and heating power simultaneously and can be driven by low grade thermal energy; it provides a good alternative for air source heat pump systems. However, conventional solid desiccant air conditioning system adopts desiccant wheel with high cost as core component, which hinders the development of such system. Recently, desiccant coated heat exchanger (DCHE) with low initial cost and high efficiency was developed and this paper aims to investigate performance of DCHE air conditioning system adopted in Shanghai winter season. Performance of the system is predicted by a developed mathematical model where supply air states, mass of humidification and coefficient of performance (COP) are adopted as performance indices to evaluate the feasibility and energy utilization ratio of the system. Effects of regeneration water temperature on system performance are analyzed. It is found that under the simulation condition, relatively low regeneration temperature (such as 20 °C) cannot meet the designed standard and relatively high regeneration temperature (such as 40 °C) provides too much extra heating power, thus moderate regeneration temperature around 30 °C is recommended. Meanwhile, switch time is a crucial operation parameter for the system to obtain satisfied supply air, switch time from 40 s to 80 s and from 70 s to 240 s are recommended for transient and average supply air states, respectively. Both

  15. Towards energy efficient operation of Heating, Ventilation and Air Conditioning systems via advanced supervisory control design

    Science.gov (United States)

    Oswiecinska, A.; Hibbs, J.; Zajic, I.; Burnham, K. J.

    2015-11-01

    This paper presents conceptual control solution for reliable and energy efficient operation of heating, ventilation and air conditioning (HVAC) systems used in large volume building applications, e.g. warehouse facilities or exhibition centres. Advanced two-level scalable control solution, designed to extend capabilities of the existing low-level control strategies via remote internet connection, is presented. The high-level, supervisory controller is based on Model Predictive Control (MPC) architecture, which is the state-of-the-art for indoor climate control systems. The innovative approach benefits from using passive heating and cooling control strategies for reducing the HVAC system operational costs, while ensuring that required environmental conditions are met.

  16. Load Distribution of Semi-Central Evaporative Cooling Air-Conditioning System Based on the TRNSYS Platform

    Directory of Open Access Journals (Sweden)

    Ji Li

    2018-05-01

    Full Text Available Evaporative cooling is a green, energy-efficient cooling technology adopted in hot and dry regions, which has wider application in the field of air-conditioning systems. Outdoor meteorological parameters have a great influence on the operation mode and control strategy of evaporative cooling air-conditioning systems, and the system load distribution and system configuration will be affected. This paper aims at investigating the load distribution of semi-central evaporative cooling air-conditioning systems under the condition of hourly outdoor meteorological parameters. Firstly, this paper introduced the design partition, operation mode, controlling strategy and load distribution method on semi-central evaporative cooling air-conditioning system. Then, taking an office building in Lanzhou (China as an example, the evaporative cooling air-conditioning system was divided into five regions and the load distribution was simulated by TRNSYS (The Transient Energy System Simulation Tool under the condition of hourly outdoor meteorological parameters. Finally, the results have shown that the evaporative cooling air-conditioning system can provide 25.46% of the building loads, which was of great significance to reduce the energy consumption of air-conditioning system.

  17. Experimental performance study of a proposed desiccant based air conditioning system.

    Science.gov (United States)

    Bassuoni, M M

    2014-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system.

  18. Modeling and Simulation of Thermal Performance of Solar-Assisted Air Conditioning System under Iraq Climate

    Directory of Open Access Journals (Sweden)

    Najim Abid Jassim

    2016-08-01

    Full Text Available In Iraq most of the small buildings deployed a conventional air conditioning technology which typically uses electrically driven compressor systems which exhibits several clear disadvantages such as high energy consumption, high electricity at peak loads. In this work a thermal performance of air conditioning system combined with a solar collector is investigated theoretically. The hybrid air conditioner consists of a semi hermetic compressor, water cooled shell and tube condenser, thermal expansion valve and coil with tank evaporator. The theoretical analysis included a simulation for the solar assisted air-conditioning system using EES software to analyze the effect of different parameters on the power consumption of compressor and the performance of system. The results show that refrigeration capacity is increased from 2.7 kW to 4.4kW, as the evaporating temperature increased from 3 to 18 ºC. Also the power consumption is increased from 0.89 kW to 1.08 kW. So the COP of the system is increased from 3.068 to 4.117. The power consumption is increased from 0.897 kW to 1.031 kW as the condensing temperature increased from 35 ºC to 45 ºC. While the COP is decreased from 3.89 to 3.1. The power consumption is decreased from 1.05 kW to 0.7kW as the solar radiation intensity increased from 300 W/m2 to 1000 W/m2, while the COP is increased from 3.15 to 4.8. A comparison between the simulation and available experimental data showed acceptable agreement.

  19. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  20. Fault diagnosis of air conditioning systems based on qualitative bond graph

    International Nuclear Information System (INIS)

    Ghiaus, C.

    1999-01-01

    The bond graph method represents a unified approach for modeling engineering systems. The main idea is that power transfer bonds the components of a system. The bond graph model is the same for both quantitative representation, in which parameters have numerical values, and qualitative approach, in which they are classified qualitatively. To infer the cause of faults using a qualitative method, a system of qualitative equations must be solved. However, the characteristics of qualitative operators require specific methods for solving systems of equations having qualitative variables. This paper proposes both a method for recursively solving the qualitative system of equations derived from bond graph, and a bond graph model of a direct-expansion, mechanical vapor-compression air conditioning system. Results from diagnosing two faults in a real air conditioning system are presented and discussed. Occasionally, more than one fault candidate is inferred for the same set of qualitative values derived from measurements. In these cases, additional information is required to localize the fault. Fault diagnosis is initiated by a fault detection mechanism which also classifies the quantitative measurements into qualitative values; the fault detection is not presented here. (author)

  1. Thermal energy recovery of air conditioning system--heat recovery system calculation and phase change materials development

    International Nuclear Information System (INIS)

    Gu Zhaolin; Liu Hongjuan; Li Yun

    2004-01-01

    Latent heat thermal energy storage systems can be used to recover the rejected heat from air conditioning systems, which can be used to generate low-temperature hot water. It decreases not only the consumption of primary energy for heating domestic hot water but also the calefaction to the surroundings due to the rejection of heat from air conditioning systems. A recovery system using phase change materials (PCMs) to store the rejected (sensible and condensation) heat from air conditioning system has been developed and studied, making up the shortage of other sensible heat storage system. Also, PCMs compliant for heat recovery of air conditioning system should be developed. Technical grade paraffin wax has been discussed in this paper in order to develop a paraffin wax based PCM for the recovery of rejected heat from air conditioning systems. The thermal properties of technical grade paraffin wax and the mixtures of paraffin wax with lauric acid and with liquid paraffin (paraffin oil) are investigated and discussed, including volume expansion during the phase change process, the freezing point and the heat of fusion

  2. Comparison of desiccant air conditioning systems with different indirect evaporative air coolers

    International Nuclear Information System (INIS)

    Pandelidis, Demis; Anisimov, Sergey; Worek, William M.; Drąg, Paweł

    2016-01-01

    Highlights: • A numerical study of desiccant air conditioning systems is presented. • The ε-NTU model is used for the analysis. • Different arrangements of the desiccant systems were compared. • The systems were compared under different operating conditions. - Abstract: This paper presents a numerical analysis of three desiccant air-conditioning systems equipped with different indirect evaporative air coolers: (1) the cross-flow Maisotsenko cycle heat and mass exchanger (HMX), (2) the regenerative counter-flow Maisotsenko cycle heat and mass exchanger and (3) the standard cross-flow evaporative air cooler. To analyze the desiccant wheel and the indirect evaporative air coolers, the modified ε-NTU-model was used. The simulations were performed under assumption that the desiccant wheel is regenerated with air heated to relatively low temperature values (50–60 °C), which can be produced with solar panels in typical moderate climatic conditions. It was established that the main advantage of the presented solutions is that they can provide comfort conditions even with less effective dehumidification. The different systems were compared under variable selected operational factors (i.e. inlet air temperature, humidity and regeneration air temperature). The analysis allowed establishing the advantages and disadvantages of presented solutions and allowed estimating their application potential.

  3. System monitoring feedback in cinemas and harvesting energy of the air conditioning condenser

    Science.gov (United States)

    Pop, P. P.; Pop-Vadean, A.; Barz, C.; Latinovic, T.; Chiver, O.

    2017-05-01

    Our article monitors the degree of emotional involvement of the audience in the action film in theaters by measuring the concentration of CO2. The software performs data processing obtained dispersion sensors and displays data during the film. The software will also trigger the start of the air conditioning condenser where we can get harvesting energy by installing a piezoelectric device. Useful energy can be recovered from various waste produced in cinema. The time lag between actions and changes in environmental systems determines that decisions made now will affect subsequent generations and the future of our environment.

  4. Duct corrosion in the ventilating air conditioning system for Main Control Room

    International Nuclear Information System (INIS)

    Yamada, Kohei; Kobayashi, Takashi; Minami, Akiko; Fukuba, Kazushi

    2014-01-01

    Higashidori Nuclear Power Station, start-of-operation in December 2005, is a relatively new plant. We decided to get original data of air duct condition to determine maintenance policy of air duct, because planned maintenance of air duct has never been done and the corrosion of air duct has occurred in other plant. In January 2014, we found a corrosion-hole at the downstream of the inlet damper in the ventilating air conditioning system for Main Control Room (MCR). We supposed that the cause of rapid corrosion is related to the characteristic environment of this site. (author)

  5. Ventilation and air conditioning system in waste treatment and storage facilities

    International Nuclear Information System (INIS)

    Kinoshita, Hirotsugu; Sugawara, Kazushige.

    1987-01-01

    So far, the measures concerning the facilities for treating and storing radioactive wastes in nuclear fuel cycle in Japan were in the state which cannot be said to be sufficient. In order to cope with this situation, electric power companies constructed and operated radioactive waste concentration and volume reduction facilities, solid waste storing facilities for drums, high level solid waste storing facilities, spent fuel cask preserving facilities and so on successively in the premises of nuclear power stations, and for the wastes expected in future, the research and the construction plan of the facilities for treating and storing low, medium and high level wastes have been advanced. The ventilation and air conditioning system for these facilities is the important auxiliary system which has the mission of maintaining safe and pleasant environment in the facilities and lowering as far as possible the release of radioactive substances to outside. The outline of waste treatment and storage facilities is explained. The design condition, ventilation and air conditioning method, the features of respective waste treatment and storage facilities, and the problems for the future are described. Hereafter, mechanical ventilation system continues to be the main system, and filters become waste, while the exchange of filters is accompanied by the radiation exposure of workers. (Kako, I.)

  6. An optimization strategy for the control of small capacity heat pump integrated air-conditioning system

    International Nuclear Information System (INIS)

    Gao, Jiajia; Huang, Gongsheng; Xu, Xinhua

    2016-01-01

    Highlights: • An optimization strategy for a small-scale air-conditioning system is developed. • The optimization strategy aims at optimizing the overall system energy consumption. • The strategy may guarantee the robust control of the space air temperature. • The performance of the optimization strategy was tested on a simulation platform. - Abstract: This paper studies the optimization of a small-scale central air-conditioning system, in which the cooling is provided by a ground source heat pump (GSHP) equipped with an on/off capacity control. The optimization strategy aims to optimize the overall system energy consumption and simultaneously guarantee the robustness of the space air temperature control without violating the allowed GSHP maximum start-ups number per hour specified by customers. The set-point of the chilled water return temperature and the width of the water temperature control band are used as the decision variables for the optimization. The performance of the proposed strategy was tested on a simulation platform. Results show that the optimization strategy can save the energy consumption by 9.59% in a typical spring day and 2.97% in a typical summer day. Meanwhile it is able to enhance the space air temperature control robustness when compared with a basic control strategy without optimization.

  7. Optimal heat rejection pressure in transcritical carbon dioxide air conditioning and heat pump systems

    DEFF Research Database (Denmark)

    Liao, Shengming; Jakobsen, Arne

    1998-01-01

    Due to the urgent need for environmentally benign refrigerants, the use of the natural substance carbon dioxide in refrigeration systems has gained more and more attention. In systems such as automobile air-conditioners and heat pumps, owing to the relatively high heat rejection temperatures, the...... dioxide air conditioning or heat pump systems and for intelligent controlling such systems.......Due to the urgent need for environmentally benign refrigerants, the use of the natural substance carbon dioxide in refrigeration systems has gained more and more attention. In systems such as automobile air-conditioners and heat pumps, owing to the relatively high heat rejection temperatures......, the cycles using carbon dioxide as refrigerant will have to operate in the transcritical area. In a transcritical carbon dioxide system, there is an optimal heat rejection pressure that gives a maximum COP. In this paper, it is shown that the value of this optimal heat rejection pressure mainly depends...

  8. Experimental evaluation of a direct air-cooled lithium bromide-water absorption prototype for solar air conditioning

    International Nuclear Information System (INIS)

    Gonzalez-Gil, A.; Izquierdo, M.; Marcos, J.D.; Palacios, E.

    2011-01-01

    A new direct air-cooled single-effect LiBr-H 2 O absorption prototype is described and proposed for use in solar cooling. As distinguishing aspects, it presents: an adiabatic absorber using flat-fan sheets; an air-cooling system that directly refrigerates both the condenser and the absorber and; the possibility of being operated also as a double-effect unit. A solar facility comprising a 48 m 2 field of flat-plate collectors was used to test the single-effect operation mode of the prototype. Results from an experimental campaign carried out in Madrid during summer 2010 are shown and operation parameters corresponding to two typical summer days are detailed. The prototype worked efficiently, with COP values around 0.6. Cooling power varied from 2 kW to 3.8 kW, which represented about 85% of the prototype's nominal capacity. Chilled water temperatures mostly ranged between 14 o C and 16 o C, although the lowest measured value was of 12.8 o C. Condensation and absorption temperatures were under 50 o C and 46 o C, respectively, even with outdoor temperatures of 40 o C. Driving water temperature ranged between 85 o C and 110 o C. As a mean, the system was able to meet 65% of the cooling demand corresponding to a room of 40 m 2 . No signs of crystallization were observed during about a hundred hours of operation. - Highlights: → A novel direct air-cooled single-effect absorption prototype is described. → Feasibility of air-cooled technology for LiBr-H 2 O absorption cooling is proved. → An adiabatic absorber using flat-fan sheets avoids crystallization of the solution. → A field of flat-plate collectors powers the chiller at temperatures from 85 to 110 o C. → The prototype works with thermal COP about 0.6.

  9. A robust model predictive control strategy for improving the control performance of air-conditioning systems

    International Nuclear Information System (INIS)

    Huang Gongsheng; Wang Shengwei; Xu Xinhua

    2009-01-01

    This paper presents a robust model predictive control strategy for improving the supply air temperature control of air-handling units by dealing with the associated uncertainties and constraints directly. This strategy uses a first-order plus time-delay model with uncertain time-delay and system gain to describe air-conditioning process of an air-handling unit usually operating at various weather conditions. The uncertainties of the time-delay and system gain, which imply the nonlinearities and the variable dynamic characteristics, are formulated using an uncertainty polytope. Based on this uncertainty formulation, an offline LMI-based robust model predictive control algorithm is employed to design a robust controller for air-handling units which can guarantee a good robustness subject to uncertainties and constraints. The proposed robust strategy is evaluated in a dynamic simulation environment of a variable air volume air-conditioning system in various operation conditions by comparing with a conventional PI control strategy. The robustness analysis of both strategies under different weather conditions is also presented.

  10. Fuzzy logic control of air-conditioning system in residential buildings

    Directory of Open Access Journals (Sweden)

    Abdel-Hamid Attia

    2015-09-01

    Full Text Available There has been a rising concern in reducing the energy consumption in building. Heating ventilation and air condition system is the biggest consumer of energy in building. In this study, fuzzy logic control of the air conditioning system of building for efficient energy operation and comfortable environment is investigated. A theoretical model of the fan coil unit (FCU and the heat transfer between air and coolant fluid is derived. The controlled variables are the room temperature and relative humidity and control consequents are the percentage of chilled and hot water flow rates at summer and the percentage of hot water and steam injected flow rates at winter. A computer simulation has been conducted and fuzzy control results are compared with that of conventional Proportional-Integral-Derivative control. It was found that the proposed control strategy satisfies the space load and at the same time to achieve the comfort zone, as defined by the ASHRAE code. Meanwhile PID control fails to adjust the room temperature at part-load operations. It has been demonstrated that fuzzy controller operation is more efficient and consumes less energy than PID control.

  11. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong.

    Science.gov (United States)

    Yan, H H; Guo, H; Ou, J M

    2014-08-15

    During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO2-equivelant (CO2-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10(5)tons CO2-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Natural convection liquid desiccant loop as an auxiliary air conditioning system: investigating the operational parameters

    Science.gov (United States)

    Fazilati, Mohammad Ali; Alemrajabi, Ali Akbar; Sedaghat, Ahmad

    2018-03-01

    Liquid desiccant air conditioning system with natural convection was presented previously as a new generation of AC systems. The system consists of two three-fluid energy exchangers namely absorber and regenerator in which the action of air dehumidifying and desiccant regeneration is done, respectively. The influence of working parameters on system performance including the heat source and heat sink temperature, concentration of desiccant solution fills the system initially and humidity content of inlet air to regenerator is investigated experimentally. The heat source temperatures of 50 °C and 60 °C, heat sink temperatures of 15 °C and 20 °C and desiccant concentrations of 30% and 34%, are examined here. The inlet air to regenerator has temperature of 38.5 °C and three relative humidity of 14%, 38% and 44%. In all experiments, the inlet air to absorber has temperature of 31 °C and relative humidity of 75%. By inspecting evaluation indexes of system, it is revealed that higher startup desiccant concentration solution is more beneficial for all study cases. It is also observed although the highest/lowest temperature heat source/heat sink is most suitable for best system operation, increasing the heat source temperature should be accompanied with decreasing heat sink temperature. Using drier air stream for regenerator inlet does not necessarily improve system performance; and the air stream with proper value of humidity content should be employed. Finally after running the system in its best working condition, the coefficient of performance (COP) reached 4.66 which verified to be higher than when the same air conditioning task done by a conventional vapor compression system, in which case the COP was 3.38.

  13. Modeling of a New Structure of Precision Air Conditioning System Using Secondary Condenser for Rh Regulation

    Directory of Open Access Journals (Sweden)

    Aries Subiantoro

    2012-05-01

    Full Text Available A dynamic mathematical model for a new structure of precision air conditioning (PAC has been developed. The proposed PAC uses an additional secondary condenser for relative humidity regulation compared to a basic refrigeration system. The work mechanism for this system and a vapour-compression cycle process of the system are illustrated using psychrometric chart and pressure-enthalpy diagram. A non-linear system model is derived based on the conservation of mass and energy balance principles and then linearized at steady state operating point for developing a 8th-order state space model suited for multivariable controller design. The quality of linearized model is analyzed in terms of transient response, controllability, observability, and interaction between input-output variables. The developed model is verified through simulation showing its ability for imitating the nonlinear behavior and the interaction of input-output variables.

  14. Comparative study of air conditioning systems with vapor compression chillers using the concept of green buildings

    Directory of Open Access Journals (Sweden)

    Gutenberg da Silva Pereira

    2015-10-01

    Full Text Available This paper sets out to compare two different cooling systems that use vapor compression chillers for air conditioning environments. It was proposed to compare different operations in isolated and combined action operations. These operations are evaluated in the concepts of green buildings. A mathematical model was developed based on the principles of mass and energy conservation and complemented by various functions so as to determine the thermophysical properties and efficiencies of the compressors. The equations of the model were solved by the EES (Engineering Equation Solver program. The model evaluates the influence of the main HVAC operating parameters of the chilled water system when operating under three different configurations. The results showed that the system with a differentiated compression presents a COP equal to that of the system with screw chillers in the range  0-300 RTs, and a COP hat is on average 9% higher in the range 400-800 RTs.

  15. Performance assessment and transient optimization of air precooling in multi-stage solid desiccant air conditioning systems

    International Nuclear Information System (INIS)

    Gadalla, Mohamed; Saghafifar, Mohammad

    2016-01-01

    Highlights: • Studying three two-stage solid desiccant cooling systems using Maisotsenko cooler. • Proposing precooling to improve two-stage desiccant systems’ COP for humid climates. • Performing transient analysis for a two-stage solid desiccant cooler in UAE. • Optimizing daily performance of a two-stage solid desiccant cooler for UAE. - Abstract: Renewable energy is one of the most promising solutions to both energy and global warming crisis. Energy consumption can be minimized considerably by utilizing solar energy in air conditioning systems operation. One of the popular solar air conditioning technologies is desiccant air conditioning. Nonetheless, conventional desiccant air conditioning systems have a relatively low coefficient of performance (COP). In consequence, two-stage desiccant air-conditioning systems are proposed to improve desiccant air conditioning systems’ COP. Moreover, a recently commercialized cooling method named Maisotsenko cooling cycle which is capable of cooling air near to its dew point temperature is considered to be integrated within the proposed multi-stage desiccant cooling systems. In this paper, three new two-stage desiccant air conditioning systems incorporating Maisotsenko cooling cycle are proposed and investigated in details for hot and humid climates such as UAE. Furthermore, air precooling is considered to improve two stage desiccant air conditioning systems’ COP. Moreover, full transient analysis and optimization are carried out in UAE within June–October. The proposed system can minimize the required solar heating during noon time as the ambient air dry bulb temperature rises. Average COP of the system during electricity load peak hours (10:00–14:00) for all five considered and combined months is 1.77. Average rate of heat input required to operate the system and average building cooling load are determined to be 100.3 kW and 46.2 kW, respectively. Therefore, system average COP is computed to be 0.46.

  16. Physiological and subjective responses in the elderly when using floor heating and air conditioning systems.

    Science.gov (United States)

    Hashiguchi, Nobuko; Tochihara, Yutaka; Ohnaka, Tadakatsu; Tsuchida, Chiaki; Otsuki, Tamio

    2004-11-01

    The purpose of this study was to investigate the effects of a floor heating and air conditioning system on thermal responses of the elderly. Eight elderly men and eight university students sat for 90 minutes in a chair under the following 3 conditions: air conditioning system (A), floor heating system (F) and no heating system (C). The air temperature of sitting head height for condition A was 25 degrees C, and the maximum difference in vertical air temperature was 4 degrees C. The air and floor temperature for condition F were 21 and 29 degrees C, respectively. The air temperature for condition C was 15 degrees C. There were no significant differences in rectal temperature and mean skin temperature between condition A and F. Systolic blood pressure of the elderly men in condition C significantly increased compared to those in condition A and F. No significant differences in systolic blood pressure between condition A and F were found. The percentage of subjects who felt comfortable under condition F was higher than that of those under condition A in both age groups, though the differences between condition F and A was not significant. Relationships between thermal comfort and peripheral (e.g., instep, calf, hand) skin temperature, and the relationship between thermal comfort and leg thermal sensation were significant for both age groups. However, the back and chest skin temperature and back thermal sensation for the elderly, in contrast to that for the young, was not significantly related to thermal comfort. These findings suggested that thermal responses and physiological strain using the floor heating system did not significantly differ from that using the air conditioning system, regardless of the subject age and despite the fact that the air temperature with the floor heating system was lower. An increase in BP for elderly was observed under the condition in which the air temperature was 15 degrees C, and it was suggested that it was necessary for the elderly

  17. Development of simulation technology on full auto air conditioning system; Auto eakon no simulation gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, N; Otsubo, Y; Matsumura, K; Sako, H [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    Mazda has developed simulation technology on control of full auto air conditioning system. We have developed the development tool based on the technology, aiming at higher controllability of full auto air conditioning system and shorter development period. The tool performs simulation on control, on-vehicle evaluation of actual load operation, collecting data and analyzing them by personal computer. This paper reports our verification results on effectiveness of the technology/ and the tool. 4 refs., 9 figs.

  18. Exergy characteristics of a ceiling-type residential air conditioning system operating under different climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ozbek, Arif [Dept. of Mechanical Engineering, Ceyhan Engineering Faculty, Cukurova University, Adana (Turkmenistan)

    2016-11-15

    In this study an energy and exergy analysis of a Ceiling-type residential air conditioning (CTRAC) system operating under different climatic conditions have been investigated for provinces within the different geographic regions of Turkey. Primarily, the hourly cooling load capacities of a sample building (Q{sub evap}) during the months of April, May, June, July, August and September were determined. The hourly total heat gain of the sample building was determined using the Hourly analysis program (HAP). The Coefficient of performance (COP), exergy efficiency (η) and exergy destruction (Ex{sub dest}) values for the whole system and for each component were obtained. The results showed that lower atmospheric temperature (T{sub atm}) influenced the performance of the system and each of its components.

  19. Absorber and regenerator models for liquid desiccant air conditioning systems. Validation and comparison using experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Krause, M.; Heinzen, R.; Jordan, U.; Vajen, K. [Kassel Univ., Inst. of Thermal Engineering, Kassel (Germany); Saman, W.; Halawa, E. [Sustainable Energy Centre, Univ. of South Australia, Mawson Lakes, Adelaide (Australia)

    2008-07-01

    Solar assisted air conditioning systems using liquid desiccants represent a promising option to decrease high summer energy demand caused by electrically driven vapor compression machines. The main components of liquid desiccant systems are absorbers for dehumidifying and cooling of supply air and regenerators for concentrating the desiccant. However, high efficient and validated reliable components are required and the design and operation have to be adjusted to each respective building design, location, and user demand. Simulation tools can help to optimize component and system design. The present paper presents new developed numerical models for absorbers and regenerators, as well as experimental data of a regenerator prototype. The models have been compared with a finite-difference method model as well as experimental data. The data are gained from the regenerator prototype presented and an absorber presented in the literature. (orig.)

  20. FY1999 Meeting of The Society of Heating, Air-Conditioning and Sanitary Engineering of Japan. Air conditioning systems for various facilities; 1999 nendo gakujutsu koenkai gaiyo. Kakushu shisetsu kucho system

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, K. [Takenaka Corp., Osaka (Japan)

    1999-12-05

    B-49 reported the outline of an artificial weather room composed of one inner room and two outer rooms, and its temperature change and temperature profiles during air conditioning. The room is scheduled to be used for evaluation of air conditioning systems, thermal performance evaluation of building materials and study on ventilation efficiency. B-50 reported the seasonal measurement results on thermal environment, and cooling and heating use patterns of living rooms and common spaces of 4 welfare homes for aged persons, and showed that room temperature difference in winter should be considered. Measurement data on facilities with floor heating were required. B-51 reported the experiment and numerical analysis results on thermal environment, draft sensation, condensation and radiation effect of patient bedrooms by using a full-scale 4-bed room model with a specific outlet developed for patient bedroom air conditioning. B-52 reported the outline of an air conditioning system for vegetable factories, and its performance evaluation result during cooling. The effect of blackout curtains and local air conditioning was reported. B-53 reported the comparison study result on air conditioning for animal breeding rooms by full-scale model experiment and numerical analysis. The line outlet + hanging wall + rack back exhaust system was most favorable from the viewpoint of temperature profile and prevention of pollutants from diffusion. (translated by NEDO)

  1. Optimization of recirculating laminar air flow in operating room air conditioning systems

    Directory of Open Access Journals (Sweden)

    Enver Yalcin

    2016-04-01

    Full Text Available The laminar flow air-conditioning system with 100% fresh air is used in almost all operating rooms without discrimination in Turkey. The laminar flow device which is working with 100% fresh air should be absolutely used in Type 1A operating rooms. However, there is not mandatory to use of 100% fresh air for Type 1B defined as places performed simpler operation. Compared with recirculating laminar flow, energy needs of the laminar flow with 100 % fresh air has been emerged about 40% more than re-circulated air flow. Therefore, when a recirculating laminar flow device is operated instead of laminar flow system with 100% fresh air in the Type 1B operating room, annual energy consumption will be reduced. In this study, in an operating room with recirculating laminar flow, optimal conditions have been investigated in order to obtain laminar flow form by analyzing velocity distributions at various supply velocities by using computational fluid dynamics method (CFD.

  2. Study and Development of an Air Conditioning System Operating on a Magnetic Heat Pump Cycle

    Science.gov (United States)

    Wang, Pao-Lien

    1991-01-01

    This report describes the design of a laboratory scale demonstration prototype of an air conditioning system operating on a magnetic heat pump cycle. Design parameters were selected through studies performed by a Kennedy Space Center (KSC) System Simulation Computer Model. The heat pump consists of a rotor turning through four magnetic fields that are created by permanent magnets. Gadolinium was selected as the working material for this demonstration prototype. The rotor was designed to be constructed of flat parallel disks of gadolinium with very little space in between. The rotor rotates in an aluminum housing. The laboratory scale demonstration prototype is designed to provide a theoretical Carnot Cycle efficiency of 62 percent and a Coefficient of Performance of 16.55.

  3. Performance of residential air-conditioning systems with flow maldistribution in fin-and-tube evaporators

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Brix, Wiebke; Elmegaard, Brian

    2011-01-01

    Refrigerant and airflow maldistribution in fin-and-tube evaporators for residential air-conditioning was investigated with numerical modeling. Fin-and-tube heat exchangers usually have a pre-defined circuitry. However, the objective in this study was to perform a generic investigation of each...... individual maldistribution source in an independent manner. Therefore, the evaporator and the condenser were simplified to be straight tubes for the purposes of this study. The numerical model of the R410A system, its verification and an investigation of individual maldistribution sources are presented...... in this paper. The maldistribution sources of interest were: inlet liquid/vapor phase distribution, feeder tube bending and airflow distribution. The results show that maldistribution reduced the cooling capacity and the coefficient of performance of the system. In particular, different phase distribution...

  4. Solar air-conditioning. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Within the 3rd International Conference on solar air-conditioning in Palermo (Italy) at 30th September to 2nd October, 2009 the following lectures were held: (1) Removal of non-technological barriers to solar cooling technology across Southern European islands (Stefano Rugginenti); (2) The added economic and environmental value of solar thermal systems in microgrids with combined heat and power (Chris Marney); (3) Australian solar cooling interest group (Paul Kohlenbach); (4) Designing of a technology roadmap for solar assisted air conditioning in Austria (Hilbert Focke); (5) Solar cooling in the new context of renewable policies at European level (Raffaele Piria); (6) Prototype of a solar driven steam jet ejector chiller (Clemens Pollerberg); (7) New integrated solar air conditioning system (Joan Carlos Bruno); (8) Primary energy optimised operation of solar driven desiccant evaporative cooling systems through innovative control strategies; (9) Green chiller association (Uli Jakob); (10) Climate Well {sup registered} (Olof Hallstrom); (11) Low capacity absorption chillers for solar cooling applications (Gregor Weidner); (12) Solar cooling in residential, small scale commercial and industrial applications with adsorption technology (Walter Mittelbach); (13) French solar heating and cooling development programme based on energy performance (Daniel Mugnier); (14) Mirrox fresnel process heat collectors for industrial applications and solar cooling (Christian Zahler); (15) Modelling and analyzing solar cooling systems in polysun (Seyen Hossein Rezaei); (16) Solar cooling application in Valle Susa Italy (Sufia Jung); (17) Virtual case study on small solar cooling systems within the SolarCombi+Project (Bjoern Nienborg); (18) Design of solar cooling plants under uncertainty (Fernando Dominguez-Munoz); (19) Fast pre-design of systems using solar thermally driven chillers (Hans-Martin Henning); (20) Design of a high fraction solar heating and cooling plant in southern

  5. Analyses of an air conditioning system with entropy generation minimization and entransy theory

    International Nuclear Information System (INIS)

    Wu Yan-Qiu; Cai Li; Wu Hong-Juan

    2016-01-01

    In this paper, based on the generalized heat transfer law, an air conditioning system is analyzed with the entropy generation minimization and the entransy theory. Taking the coefficient of performance (denoted as COP ) and heat flow rate Q out which is released into the room as the optimization objectives, we discuss the applicabilities of the entropy generation minimization and entransy theory to the optimizations. Five numerical cases are presented. Combining the numerical results and theoretical analyses, we can conclude that the optimization applicabilities of the two theories are conditional. If Q out is the optimization objective, larger entransy increase rate always leads to larger Q out , while smaller entropy generation rate does not. If we take COP as the optimization objective, neither the entropy generation minimization nor the concept of entransy increase is always applicable. Furthermore, we find that the concept of entransy dissipation is not applicable for the discussed cases. (paper)

  6. Instability of automotive air conditioning system with a variable displacement compressor. Part 1. Experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Changqing; Dou, Chunpeng; Yang, Xinjiang; Li, Xianting [Department of Building Science, School of Architecture, Tsinghua University, Beijing 100084 (People' s Republic of China)

    2005-11-01

    A test system is built first in order to investigate the instability of the automotive air conditioning (AAC) system with a variable displacement compressor (VDC), and hunting phenomena caused by the large external disturbance in the AAC system with a VDC and a thermal expansion valve, and in the AAC system with a VDC and a fixed-area throttling device are investigated experimentally in part 1 of this paper. The experimental results indicate that there also exist the hunting phenomena in the AAC system with a fixed-area throttling device. The system stability is found to be dependent on the direction of the external disturbance, and the system is apt to cause hunting when the condensing pressure decreases excessively since it may cause two-phase state at the throttling device inlet and make a large disturbance to the system. The piston stroke length will oscillate only when the oscillation amplitudes of forces acting on the wobble plate are great enough, otherwise the piston stroke length will be kept invariable, and then the system instability rule is also suitable for the AAC system with a fixed displacement compressor. From the experimental results, it is concluded that the two-phase flow at the throttling device inlet or at the evaporator outlet is the necessary condition but not sufficient condition for system hunting. Finally, a new concept, conservative stable region, is proposed based on the experimental results and theoretical analysis. (author)

  7. Remote Supervision and Control of Air Conditioning Systems in Different Modes

    Science.gov (United States)

    Rafeeq, Mohammed; Afzal, Asif; Rajendra, Sree

    2018-01-01

    In the era of automation, most of the application of engineering and science are interrelated with system for optimal operation. To get the efficient result of an operation and desired response, interconnected systems should be controlled by directing, regulating and commanding. Here, air conditioning (AC) system is considered for experimentation, to supervise and control its functioning in both, automated and manual mode. This paper reports the work intended to design and develop an automated and manual AC system working in remote and local mode, to increase the level of comfort, easy operation, reducing human intervention and faults occurring in the system. The Programmable Logical Controller (PLC) and Supervisory Control and Data Acquisition (SCADA) system were used for remote supervision and monitoring of AC systems using series ninety protocol and remote terminal unit modbus protocol as communication module to operate in remote mode. PLC was used as remote terminal for continuous supervision and control of AC system. SCADA software was used as a tool for designing user friendly graphical user interface. The proposed SCADA AC system successfully monitors and controls in accordance within the parameter limits like temperature, pressure, humidity and voltage. With all the features, this designed system is capable of efficient handling of the resources like the compressor, humidifier etc., with all the levels of safety and durability. This system also maintains the temperature and controls the humidity of the remote location and also looks after the health of the compressor.

  8. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong

    International Nuclear Information System (INIS)

    Yan, H.H.; Guo, H.; Ou, J.M.

    2014-01-01

    Highlights: • Halocarbon emissions from MVACS were characterized using bottom up approach. • Quantification of emission inventory was revealed using AUV Tools. • Potential emission reduction was estimated under 3 possible mitigation scenarios. • The results are useful for the policy makers to formulate and implement future phase-out schedule. - Abstract: During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO 2 -equivelant (CO 2 -eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10 5 tons CO 2 -eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong

  9. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Yan, H.H.; Guo, H., E-mail: ceguohai@polyu.edu.hk; Ou, J.M.

    2014-08-15

    Highlights: • Halocarbon emissions from MVACS were characterized using bottom up approach. • Quantification of emission inventory was revealed using AUV Tools. • Potential emission reduction was estimated under 3 possible mitigation scenarios. • The results are useful for the policy makers to formulate and implement future phase-out schedule. - Abstract: During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO{sub 2}-equivelant (CO{sub 2}-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10{sup 5} tons CO{sub 2}-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong.

  10. Experimental verification of a condenser with liquid–vapor separation in an air conditioning system

    International Nuclear Information System (INIS)

    Chen, Xueqing; Chen, Ying; Deng, Lisheng; Mo, Songping; Zhang, Haiyan

    2013-01-01

    Three liquid–vapor separation condensers (LSC) were tested to evaluate their ability to automatically separate the liquid and vapor during condensation. Each was used in a split-type air conditioner to investigate the performance. The performance of the LSC system having the greatest cooling capacity and energy efficiency ratio (EER) was then compared with that of the system having a baseline fin-and-tube condenser for various ambient temperatures from 29 °C to 43 °C. The results showed that both the cooling capacity and EER of the two systems were almost the same at the three standard conditions in the Chinese standard GB/T 7725-2004, with the LSC having just 67% of the heat transfer area of the baseline condenser. In addition, the LSC system was charged with only 80% of the refrigerant in the baseline system. -- Highlights: ► We tested three liquid–vapor separation condensers in an air conditioning system. ► The best system had the most uniform wall temperature and the smallest pressure drop. ► The LSC system performance with only 67% condenser area was as good as the baseline system. ► LSC system operations are compared for various outdoor temperatures

  11. HVAC-DYNAMICS - a tool for quality assurance in relation to delivery of air-conditioning systems. [Heating, ventilating and air conditioning]. HVAC-DYNAMICS - et redskap for kvalitetsikring av sluttleveransen i klima-anlegg

    Energy Technology Data Exchange (ETDEWEB)

    Novakovic, V [SINTEF Varmeteknikk, Seksjon VVS (NO)

    1990-07-01

    HVAC-DYNAMICS is a computerized tool for quality assurance of the functioning of an air-conditioning system at the time of delivery. The system's efficiency in the case of fluctuating and critical operation is evaluated. The HVAC-DYNAMICS gives an optimal choice for air-conditioning systems regarding indoor climate, efficiency demands and energy consumption. The program can also be use for calibration of regulators, fault-finding, and training purposes. (CLS).

  12. Online optimal control of variable refrigerant flow and variable air volume combined air conditioning system for energy saving

    International Nuclear Information System (INIS)

    Zhu, Yonghua; Jin, Xinqiao; Du, Zhimin; Fang, Xing

    2015-01-01

    The variable refrigerant flow (VRF) and variable air volume (VAV) combined air conditioning system can solve the problem of the VRF system in outdoor air ventilation while taking advantage of its high part load energy efficiency. Energy performance of the combined air conditioning system can also be optimized by joint control of both the VRF and the VAV parts. A model-based online optimal control strategy for the combined air conditioning system is presented. Simplified adaptive models of major components of the combined air conditioning system are firstly developed for predicting system performances. And a cost function in terms of energy consumption and thermal comfort is constructed. Genetic algorithm is used to search for the optimal control sets. The optimal control strategy is tested and evaluated through two case studies based on the simulation platform. Results show that the optimal strategy can effectively reduce energy consumption of the combined air conditioning system while maintaining acceptable thermal comfort. - Highlights: • A VRF and VAV combined system is proposed. • A model-based online optimal control strategy is proposed for the combined system. • The strategy can reduce energy consumption without sacrificing thermal comfort. • Novel simplified adaptive models are firstly developed for the VRF system

  13. Experimental study on frosting control of mobile air conditioning system with microchannel evaporator

    International Nuclear Information System (INIS)

    Qu Xiaohua; Shi Junye; Qi Zhaogang; Chen Jiangping

    2011-01-01

    In this paper, a newly developed frost control system is proposed. System bench tests and vehicle test in wind tunnel have been carried out to explore the anti-frosting performance of automotive air conditioning system with microchannel evaporator. The experimental results are compared with the baseline conventional laminated evaporator system. The test results show that the installation position of temperature sensor can dramatically affect the anti-frosting performance. The clutch switching on/off temperature range of the microchannel evaporator is also experimentally studied. The test results show that, with a proper installation position and on/off temperature range, the system COP can be improved, and meanwhile the panel vents' air off temperature can be reduced, and temperature swing can be reduced. - Highlights: → The frost control systems were tested with microchannel and laminated evaporators separately. → The installation position of temperature sensor affects the anti-frosting performance. → Temperature control range affects the anti-frosting performance. → The panel vents' air off temperature and swing can be reduced by proper control parameters. → The system COP can be improved by proper control parameters.

  14. Variable structure TITO fuzzy-logic controller implementation for a solar air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Lygouras, J.N.; Pachidis, Th. [Laboratory of Electronics, School of Electrical and Computer Engineering, Democritus University of Thrace, GR-67100 Xanthi (Greece); Kodogiannis, V.S. [Centre for Systems Analysis, School of Computer Science, University of Westminster, London HA1 3TP (United Kingdom); Tarchanidis, K.N. [Department of Petroleum Technology, Technological Education Institute of Kavala, GR-65404, Kavala (Greece); Koukourlis, C.S. [Laboratory of Telecommunications, School of Electrical and Computer Engineering, Democritus University of Thrace, GR-67100 Xanthi (Greece)

    2008-04-15

    The design and implementation of a Two-Input/Two-Output (TITO) variable structure fuzzy-logic controller for a solar-powered air-conditioning system is described in this paper. Two DC motors are used to drive the generator pump and the feed pump of the solar air-conditioner. The first affects the temperature in the generator of the solar air-conditioner, while the second, the pressure in the power loop. The difficulty of Multi-Input/Multi-Output (MIMO) systems control is how to overcome the coupling effects among each degree of freedom. First, a traditional fuzzy-controller has been designed, its output being one of the components of the control signal for each DC motor driver. Secondly, according to the characteristics of the system's dynamics coupling, an appropriate coupling fuzzy-controller (CFC) is incorporated into a traditional fuzzy-controller (TFC) to compensate for the dynamic coupling among each degree of freedom. This control strategy simplifies the implementation problem of fuzzy control, but can also improve the control performance. This mixed fuzzy controller (MFC) can effectively improve the coupling effects of the systems, and this control strategy is easy to design and implement. Experimental results from the implemented system are presented. (author)

  15. Development of a dynamic model for a DX VAV air conditioning system

    International Nuclear Information System (INIS)

    Chen Wu; Deng Shiming

    2006-01-01

    A direct expansion (DX) variable air volume (VAV) air conditioning (A/C) system consists of a VAV air distribution subsystem and a DX refrigeration plant. This paper reports on the development of a representative and complete dynamic mathematical model for the DX VAV A/C system having a variable speed compressor and pressure independent VAV terminals. The model is component based and takes into account the dynamic behaviors of both the DX refrigeration plant and the VAV air distribution subsystem simultaneously. The dynamic model has been developed based on the principles of mass and energy conservation and using correlations describing the operational performance of some of the system's components, which are either field tested or available from manufacturers. An experimental rig has been set up for the DX VAV A/C system, and experimental work has been conducted to obtain the system's responses to the step change of compressor speed. The dynamic model developed was then validated using the experimental data obtained. Steady state and transient responses for five major operating parameters obtained from both the model and the experiment were compared and found to be in good agreement

  16. Building occupancy diversity and HVAC (heating, ventilation, and air conditioning) system energy efficiency

    International Nuclear Information System (INIS)

    Yang, Zheng; Ghahramani, Ali; Becerik-Gerber, Burcin

    2016-01-01

    Approximately forty percent of total building energy consumption is attributed to HVAC (heating, ventilation, and air conditioning) systems that aim to maintain healthy and comfortable indoor environments. An HVAC system is a network with several subsystems, and there exist heat transfer and balance among the zones of a building, as well as heat gains and losses through a building's envelope. Diverse occupancy (diversity in terms of when and how occupants occupy a building) in spaces could result in increase of loads that are not actual demands for an HVAC system, leading into inefficiencies. This paper introduces a framework to quantitatively evaluate the energy implications of occupancy diversity at the building level, where building information modeling is integrated to provide building geometries, HVAC system layouts, and spatial information as inputs for computing potential energy implications if occupancy diversity were to be eliminated. An agglomerate hierarchical clustering-based iterative evaluation algorithm is designed for iteratively eliminating occupancy diversity. Whole building energy simulations for a real-world building, as well as virtual reference buildings demonstrate that the proposed framework could effectively quantify the HVAC system energy efficiency affected by occupancy diversity and the framework is generalizable to different building geometries, layouts, and occupancy diversities. - Highlights: • Analyze relationships between occupancy diversity and HVAC energy efficiency. • Integrate BIM for quantifying energy implications of occupancy diversity. • Demonstrate the effectiveness and generalizability of iterative evaluation algorithm. • Improve agglomerative hierarchical clustering process using heap data structure.

  17. Parametric analysis of a combined dew point evaporative-vapour compression based air conditioning system

    Directory of Open Access Journals (Sweden)

    Shailendra Singh Chauhan

    2016-09-01

    Full Text Available A dew point evaporative-vapour compression based combined air conditioning system for providing good human comfort conditions at a low cost has been proposed in this paper. The proposed system has been parametrically analysed for a wide range of ambient temperatures and specific humidity under some reasonable assumptions. The proposed system has also been compared from the conventional vapour compression air conditioner on the basis of cooling load on the cooling coil working on 100% fresh air assumption. The saving of cooling load on the coil was found to be maximum with a value of 60.93% at 46 °C and 6 g/kg specific humidity, while it was negative for very high humidity of ambient air, which indicates that proposed system is applicable for dry and moderate humid conditions but not for very humid conditions. The system is working well with an average net monthly power saving of 192.31 kW h for hot and dry conditions and 124.38 kW h for hot and moderate humid conditions. Therefore it could be a better alternative for dry and moderate humid climate with a payback period of 7.2 years.

  18. Thermal and economical optimization of air conditioning units with vapor compression refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Sanaye, S.; Malekmohammadi, H.R. [Iran University of Science and Technology, Tehran (Iran). Dept. of Mechanical Engineering

    2004-09-01

    A new method of thermal and economical optimum design of air conditioning units with vapor compression refrigeration system, is presented. Such a system includes compressor, condenser, evaporator, centrifugal and axial fans. Evaporator and condenser temperatures, their heating surface areas (frontal surface area and number of tubes), centrifugal and axial fan powers, and compressor power are among the design variables. The data provided by manufacturers for fan (volume flow rate versus pressure drop) and compressor power (using evaporator and condenser temperatures) was used to choose these components directly from available data for consumers. To study the performance of the system under various situations, and implementing the optimization procedure, a simulation program including all thermal and geometrical parameters was developed. The objective function for optimization was the total cost per unit cooling load of the system including capital investment for components as well as the required electricity cost. To find the system design parameters, this objective function was minimized by Lagrange multipliers method. The effects of changing the cooling load on optimal design parameters were studied. (author)

  19. A study of energy use for ventilation and air-conditioning systems in Hong Kong

    Science.gov (United States)

    Yu, Chung Hoi Philip

    Most of the local modern buildings are high-rise with enclosed structure. Mechanical ventilation and air conditioning (MVAC) systems are installed for thermal comfort. Various types of MVAC systems found in Hong Kong were critically reviewed with comments on their characteristics in energy efficiency as well as application. The major design considerations were also discussed. Besides MVAC, other energy-consuming components in commercial buildings were also identified, such as lighting, lifts and escalators, office equipment, information technology facilities, etc. A practical approach has been adopted throughout this study in order that the end results will have pragmatic value to the heating, ventilating and air-conditioning (HVAC) industry in Hong Kong. Indoor Air Quality (IAQ) has become a major issue in commercial buildings worldwide including Hong Kong. Ventilation rate is no doubt a critical element in the design of HVAC systems, which can be realized more obviously in railway train compartments where the carbon dioxide level will be built up quickly when the compartments are crowded during rush hours. A study was carried out based on a simplified model using a train compartment that is equipped with an MVAC system. Overall Thermal Transfer Value (OTTV) is a single-value parameter for controlling building energy use and is relatively simple to implement legislatively. The local government has taken a first step in reacting to the worldwide concern of energy conservation and environmental protection since 1995. Different methods of OTTV calculation were studied and the computation results were compared. It gives a clear picture of the advantages and limitations for each method to the building designers. However, due to the limitations of using OTTV as the only parameter for building energy control, some new approaches to a total control of building energy use were discussed and they might be considered for future revision of the building energy codes in Hong

  20. The performance of a mobile air conditioning system with a water cooled condenser

    International Nuclear Information System (INIS)

    Di Battista, Davide; Cipollone, Roberto

    2015-01-01

    Vehicle technological evolution lived, in recent years, a strong acceleration due to the increased awareness of environmental issues related to pollutants and climate altering emissions. This resulted in a series of international regulations on automotive sector which put technical challenges that must consider the engine and the vehicle as a global system, in order to improve the overall efficiency of the system. The air conditioning system of the cabin, for instance, is the one of the most important auxiliaries in a vehicle and requires significant powers. Its performances can be significantly improved if it is integrated within the engine cooling circuit, eventually modified with more temperature levels.In this paper, the Authors present a mathematical model of the A/C system, starting from its single components: compressors, condenser, flush valve and evaporator and a comparison between different refrigerant fluid. In particular, it is introduced the opportunity to have an A/C condenser cooled by a water circuit instead of the external air linked to the vehicle speed, as in the actual traditional configuration. The A/C condenser, in fact, could be housed on a low temperature water circuit, reducing the condensing temperature of the refrigeration cycle with a considerable efficiency increase. (paper)

  1. Modelica Library for Building Heating, Ventilation and Air-Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wetter, Michael

    2009-06-17

    This paper presents a freely available Modelica library for building heating, ventilation and air conditioning systems. The library is based on the Modelica.Fluid library. It has been developed to support research and development of integrated building energy and control systems. The primary applications are controls design, energy analysis and model-based operation. The library contains dynamic and steady-state component models that are applicable for analyzing fast transients when designing control algorithms and for conducting annual simulations when assessing energy performance. For most models, dimensional analysis is used to compute the performance for operating points that differ from nominal conditions. This allows parameterizing models in the absence of detailed geometrical information which is often impractical to obtain during the conceptual design phase of building systems. In the first part of this paper, the library architecture and the main classes are described. In the second part, an example is presented in which we implemented a model of a hydronic heating system with thermostatic radiator valves and thermal energy storage.

  2. Modeling and simulation of a solar powered two bed adsorption air conditioning system

    International Nuclear Information System (INIS)

    Li Yong; Sumathy, K.

    2004-01-01

    A simple lumped parameter model is established to investigate the performance of a solar powered adsorption air conditioning system driven by flat-type solar collectors with three different configurations of glazes: (i) single glazed cover; (ii) double glazed cover and (iii) transparent insulation material (TIM) cover. The dynamic performance of a continuous adsorption cycle using a double adsorber along with heat recovery is measured in terms of the temperature histories, gross solar coefficient of performance and specific cooling power. Also, the influences of some important design and operational parameters on the performance of the system are studied. It is found that the chosen three types of collector configurations make no big difference on the performance, but the adsorbent mass and lumped capacitance have significant effects on the system performance as well as on the system size. Simulation results indicate that the effect of overall heat transfer coefficient is not predominant if the cycle duration is longer. Also, there exists an optimum time to initiate the heating of the adsorbent bed in a day's operation

  3. Adsorption cold storage system with zeolite-water working pair used for locomotive air conditioning

    International Nuclear Information System (INIS)

    Lu, Y.Z.; Wang, R.Z.; Zhang, M.; Jiangzhou, S.

    2003-01-01

    Adsorption cold storage has lately attracted attention for its large storage capacity and zero cold energy loss during the storing process. Thermodynamic and experimental studies on the cold storage capacity and the cold discharging process, in which the adsorber is either air cooled or adiabatic, have been presented. An adsorption cold storage system with zeolite-water working pair has been developed, and some operating results are summarized. This system is used for providing air conditioning for the driver's cab of an internal combustion locomotive. Unlike a normal adsorption air conditioner, the system starts running with the adsorption process, during which the cold energy stored is discharged, and ends running with the generation process. The adsorbent temperature decreases during the cold storing period between two runs. The refrigeration power output for the whole running cycle is about 4.1 kW. It appears that such a system is quite energetically efficient and is comparatively suitable for providing discontinuous refrigeration capacity when powered by low grade thermal energy, such as industrial exhausted heat or solar energy

  4. The performance of a mobile air conditioning system with a water cooled condenser

    Science.gov (United States)

    Di Battista, Davide; Cipollone, Roberto

    2015-11-01

    Vehicle technological evolution lived, in recent years, a strong acceleration due to the increased awareness of environmental issues related to pollutants and climate altering emissions. This resulted in a series of international regulations on automotive sector which put technical challenges that must consider the engine and the vehicle as a global system, in order to improve the overall efficiency of the system. The air conditioning system of the cabin, for instance, is the one of the most important auxiliaries in a vehicle and requires significant powers. Its performances can be significantly improved if it is integrated within the engine cooling circuit, eventually modified with more temperature levels. In this paper, the Authors present a mathematical model of the A/C system, starting from its single components: compressors, condenser, flush valve and evaporator and a comparison between different refrigerant fluid. In particular, it is introduced the opportunity to have an A/C condenser cooled by a water circuit instead of the external air linked to the vehicle speed, as in the actual traditional configuration. The A/C condenser, in fact, could be housed on a low temperature water circuit, reducing the condensing temperature of the refrigeration cycle with a considerable efficiency increase.

  5. The study of operating an air conditioning system using Maisotsenko-Cycle

    Science.gov (United States)

    Khan, Mohammad S.; Tahan, Sami; Toufic El-Achkar, Mohamad; Abou Jamus, Saleh

    2018-03-01

    The project aims to design and build an air conditioning system that runs on the Maisotsenko cycle. The system is required to condition and cool down ambient air for a small residential space with the reduction in the use of electricity and eliminating the use of commercial refrigerants. This project can operate at its optimum performance in remote areas like oil diggers and other projects that run in the desert or any site that would not have a very high relative humidity level. The Maisotsenko cycle is known as the thermodynamic concept that captures energy from the air by using the psychometric renewable energy available in the latent heat in water evaporating in air. The heat and mass exchanger design was based on choosing a material that would-be water resistant and breathable, which was found to be layers of cardboard placed on top of each other and thus creating channels for air to pass through. Aiming for this design eliminates any high power electrical equipment such as compressors, condensers and evaporators that would be used in an AC system with the exception of a 600 W blower and a 10 W fan, thus making it a more environmentally friendly project. Moreover, the project is limited by the ambient temperature and humidity, as the model operates at an optimum when the relative humidity is lower.

  6. Energy-Saving Benefits of Adiabatic Humidification in the Air Conditioning Systems of Semiconductor Cleanrooms

    Directory of Open Access Journals (Sweden)

    Min-Suk Jo

    2017-11-01

    Full Text Available This paper aimed to evaluate the applicability of adiabatic humidification in the heating, ventilation, and air conditioning (HVAC systems of semiconductor cleanrooms. Accurate temperature and humidity control are essential in semiconductor cleanrooms and high energy consumption steam humidification is commonly used. Therefore, we propose an adiabatic humidification system employing a pressurized water atomizer to reduce the energy consumption. The annual energy consumption of three different HVAC systems were analyzed to evaluate the applicability of adiabatic humidification. The studied cases were as follows: (1 CASE 1: a make-up air unit (MAU with a steam humidifier, a dry cooling coil (DCC, and a fan filter unit (FFU; (2 CASE 2: a MAU with the pressurized water atomizer, a DCC, and a FFU; and (3 CASE 3: a MAU, a DCC, and a FFU, and the pressurized water atomizer installed in the return duct. The energy saving potential of adiabatic humidification over steam humidification has been proved, with savings of 8% and 23% in CASE 2 and CASE 3 compared to CASE 1, respectively. Furthermore, the pressurized water atomizer installed in the return duct exhibits greater energy saving effect than when installed in the MAU.

  7. Mode switching control of dual-evaporator air-conditioning systems

    International Nuclear Information System (INIS)

    Lin, J.-L.; Yeh, T.-J.

    2009-01-01

    Modern air-conditioners incorporate variable-speed compressors and variable-opening expansion valves as the actuators for improving cooling performance and energy efficiency. These actuators have to be properly feedback-controlled; otherwise the systems may exhibit even poorer performance than the conventional machines which use fixed-speed compressors and mechanical expansion valves. Particularly for an air-conditioner with multiple evaporators, there are occasions that the machine is operated in a mode that only selected evaporator(s) is(are) turned on, and switching(s) between modes occurs(occur) during the control process. In this case, one needs to have more carefully designed control and switching strategies to ensure the system performance. In this paper, a framework for mode switching control of the dual-evaporator air-conditioning (DEAC) system is proposed. The framework is basically an integration of a controller and a dynamic compensator. The controller, which possesses the flow-distribution capability and assumes both evaporators are on throughout the control process, is intended to provide nominal performance. While mode switching is achieved by varying the reference settings in the controller, the dynamic compensator is used to improve the transient responses immediately after the switching. Experiments indicate that the proposed framework can achieve satisfactory indoor temperature regulation and provide bumpless switching between different modes of operation.

  8. [Disinfectants and main sanitary and preventive measures for protection of ventilation and air-conditioning systems from Legionella contamination].

    Science.gov (United States)

    Gerasimov, V N; Golov, E A; Khramov, M V; Diatlov, I A

    2008-01-01

    The study was devoted to selection and assessment of disinfecting preparations for prevention of contamination by Legionella. Using system of criteria for quality assessment of disinfectants, seven newdomestic ones belonging to quaternary ammonium compounds class or to oxygen-containing preparations and designed for disinfecting of air-conditioning and ventilation systems were selected. Antibacterial and disinfecting activities of working solutions of disinfectants were tested in laboratory on the test-surfaces and test-objects of premises' air-conditioning and ventilation systems contaminated with Legionella. High antimicrobial and disinfecting activity of new preparations "Dezactiv-M", "ExtraDez", "Emital-Garant", "Aquasept Plus", "Samarovka", "Freesept", and "Ecobreeze Oxy" during their exposure on objects and materials contaminated with Legionella was shown. Main sanitary and preventive measures for defending of air-conditioning and ventilation systems from contamination by Legionella species were presented.

  9. Fuzzy logic controller implementation for a solar air-conditioning system

    International Nuclear Information System (INIS)

    Lygouras, J.N.; Botsaris, P.N.; Vourvoulakis, J.; Kodogiannis, V.

    2007-01-01

    The implementation of a variable structure fuzzy logic controller for a solar powered air conditioning system and its advantages are investigated in this paper. Two DC motors are used to drive the generator pump and the feed pump of the solar air-conditioner. Two different control schemes for the DC motors rotational speed adjustment are implemented and tested: the first one is a pure fuzzy controller, its output being the control signal for the DC motor driver. A 7 x 7 fuzzy matrix assigns the controller output with respect to the error value and the derivative of the error. The second scheme is a two-level controller. The lower level is a conventional PID controller, and the higher level is a fuzzy controller acting over the parameters of the low level controller. Step response of the two control loops are presented as experimental results. The contribution of this design is that in the control system, the fuzzy logic is implemented through software in a common, inexpensive, 16-bit microcontroller, which does not have special abilities for fuzzy control

  10. Incorporating fan control into air-conditioning systems to improve energy efficiency and transient response

    International Nuclear Information System (INIS)

    Yeh, T.-J.; Chen, Yun-Jih; Hwang, Wei-Yang; Lin, Jin-Long

    2009-01-01

    Modern air-conditioners frequently incorporate variable-speed compressors and variable-opening expansion valves with feedback control to improve performance and power efficiency. Because making the fan speeds adjustable adds flexibility to the control design and thus can lead to further improvements in performance and efficiency, this paper proposes two control algorithms, respectively, incorporating the outdoor fan and the indoor fan as the additional control inputs for air-conditioning systems. Both of the control algorithms are designed based on a low-order, linear model obtained from system identification. The first algorithm, which modulates the outdoor fan speed, can reduce the steady state power consumption if the temperature difference between the condenser and the outdoor environment is controlled properly. The second algorithm, which adds one more degree of freedom to control by modulating the indoor fan speed, can improve the transient response because actuator saturations become less likely to occur. The two control algorithms are implemented on a split-type residential air-conditioner and their respective performance is validated experimentally.

  11. Fuzzy logic controller implementation for a solar air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Lygouras, J.N.; Vourvoulakis, J. [Laboratory of Electronics, School of Electrical and Computer Engineering, Democritus University of Thrace, Vas. Sofias 12, 67100 Xanthi (Greece); Botsaris, P.N. [Laboratory of Materials, Processes and Mechanical Design, School of Production and Management Engineering, Democritus University of Thrace 67100 Xanthi (Greece); Kodogiannis, V. [Centre for Systems Analysis, School of Computer Science, University of Westminster, London, HA1 3TP (United Kingdom)

    2007-12-15

    The implementation of a variable structure fuzzy logic controller for a solar powered air conditioning system and its advantages are investigated in this paper. Two DC motors are used to drive the generator pump and the feed pump of the solar air-conditioner. Two different control schemes for the DC motors rotational speed adjustment are implemented and tested: the first one is a pure fuzzy controller, its output being the control signal for the DC motor driver. A 7 x 7 fuzzy matrix assigns the controller output with respect to the error value and the derivative of the error. The second scheme is a two-level controller. The lower level is a conventional PID controller, and the higher level is a fuzzy controller acting over the parameters of the low level controller. Step response of the two control loops are presented as experimental results. The contribution of this design is that in the control system, the fuzzy logic is implemented through software in a common, inexpensive, 16-bit microcontroller, which does not have special abilities for fuzzy control. (author)

  12. Radon mitigation in schools utilising heating, ventilating and air conditioning systems

    International Nuclear Information System (INIS)

    Fisher, G.; Ligman, B.; Brennan, T.; Shaughnessy, R.; Turk, B.H.; Snead, B.

    1994-01-01

    As part of a continuing radon in schools technology development effort, EPA's School Evaluation Team has performed radon mitigation in schools by the method of ventilation/pressurisation control technology. Ventilation rates were increased, at a minimum, to meet the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) standard, Ventilation for Acceptable Indoor Air Quality (ASHRAE 62-1989). This paper presents the results and the preliminary evaluations which led to the team's decision to implement this technology. Factors considered include energy penalties, comfort, indoor air quality (IAQ), building shell tightness, and equipment costs. Cost benefit of heat recovery ventilation was also considered. Earlier results of the SEP team's efforts have indicated a severe ventilation problem within the schools of the United States. Two case studies are presented where HVAC technology was implemented for controlling radon concentrations. One involved the installation of a heat recovery ventilator to depressurise a crawl space and provide ventilation to the classrooms which previously had no mechanical ventilation. The other involved the restoration of a variable air volume system in a two-storey building. The HVAC system's controls were restored and modified to provide a constant building pressure differential to control the entry of radon. Pre-mitigation and post-mitigation indoor air pollutant measurements were taken, including radon, carbon dioxide (CO 2 ), particulates, and bio-aerosols. Long-term monitoring of radon, CO 2 , building pressure differentials, and indoor/outdoor temperature and relative humidity is presented. (author)

  13. Health risk air-conditioning system; Insufficient maintenance increases the risk of illness. Gesundheitsrisiko Klimaanlagen; Unzureichende Wartung erhoeht das Erkrankungsrisiko

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1994-01-01

    In Germany every fifth employee who works in air-conditioned rooms complains about headache, an increased proneness to colds and influenza infections as well as allergic reactions. These troubles are often caused by the insufficient maintenance of air-conditioning systems. At present only 15% of the estimated annual demand for maintenance of space hvac-systems is actually carried out. Problematic in case of air-conditioning systems are the so-called air washers used for air humidification which can become an ideal cultur medium for microorganisms. A second problematic area are the often very dirty filters. But health risks can be avoided with regular expert maintenance alone. As first step an analysis of the causes of faults is proposed. (BWI)

  14. Determination of the ejector dimensions of a bus air-conditioning system using analytical and numerical methods

    International Nuclear Information System (INIS)

    Ünal, Şaban

    2015-01-01

    Comfortable journey with commercial buses is an essential goal of transportation companies. An air-conditioning system can play an important role for this comfortable journey but it can put extra load on the engine and extra cost in the fuel consumption. The purpose of this work is to increase the performance of air-conditioning system of the buses by reducing the load on the engine and fuel consumption. Using a two-phase ejector as an expansion valve can increase the coefficient of performance (COP) of the air-conditioning system. An improvement in the COP can reduce the empty vehicle weight and fuel consumption of buses. Two-phase ejector dimensions can be determined using the empirical methods available in the literature. In this paper, the two-phase ejector dimensions of air conditioning system for a bus are calculated using the analytical and numerical methods. First of all, the thermodynamic analysis of the vapor-compression refrigeration cycle with a two-phase ejector is performed, and then the ejector dimensions are subsequently determined. The cooling loads of the midibus and bus with R134a as a refrigerant are assumed to be 14 kW and 32 kW, respectively. The total length of the two-phase ejector for the midibuses and buses due to these cooling loads, are computed to be 480.8 mm and 793.1 mm, respectively. Also, an experimental setup is installed on a midibus air conditioner to turn it into the ejector air conditioning system to validate theoretical results with the experimental study. - Highlights: • Determination of two-phase ejector dimensions of a bus air-conditioning system. • Thermodynamic analysis of the two-phase ejector cooling system. • Experimental study on a midibus air conditioner using two-phase ejector.

  15. Feasibility study of a novel dew point air conditioning system for China building application

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xudong; Yang, Shuang; Duan, Zhiyin; Riffat, Saffa B. [School of the Built Environment, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2009-09-15

    The paper investigated the feasibility of a novel dew point evaporative cooling for air conditioning of buildings in China regions. The issues involved include analyses of China weather conditions, investigation of availability of water for dew point cooling, and assessment of cooling capacity of the system within various regions of China. It is concluded that the dew point system is suitable for most regions of China, particularly northern and west regions of China where the climate is hot and dry during the summer season. It is less suitable for Guangzhou and Shanghai where climates are hot and humid. However, an air pre-treatment process involving a silica-gel dehumidification will enable the technology to be used for these humid areas. Lower humidity results in a higher difference between the dry bulb and dew point of the air, which benefits the system in terms of enhancing its cooling performance. Tap water has adequate temperature to feed the system for cooling and its consumption rate is in the range 2.6-3 litres per kWh cooling output. The cooling output of the system ranges from 1.1 to 4.3 W per m{sup 3}/h air flow rate in China, depending on the region where the system applies. For a unit with 2 kW of cooling output, the required air volume flow rate varies with its application location and is in the range 570-1800 m{sup 3}/h. For a 50 m{sup 2} building with 60 W/m{sup 2} cooling load, if the system operates at working hours, i.e., 09:00 to 17:00 h, its daily water consumption would be in the range of 60-70 litres. Compared with mild or humid climates, the dry and hot climates need less air volume flow rate and less water. (author)

  16. Acaroid mite allergens from the filters of air-conditioning system in China.

    Science.gov (United States)

    Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping

    2014-01-01

    Accumulation of acaroid mites in the filters of air-conditioners is harmful to human health. It is important to clarify the allergen components of mites from the filters of local air-conditioning system. The present study was to detect the allergen types in the filters of air-conditioners and assesse their allergenicity by asthmatic models. Sixty aliquots of dust samples were collected from air conditioning filters in civil houses in Wuhu area. Total protein was extracted from the dust samples using PBS and quantified by Bradford method. Allergens I and II were also detected by Western blot using primary antibody (anti-Der f1/2, Der p1/Der f2/Der p2, respectively). Ten aliquots of the positive samples were randomly selected for homogenization and sensitized the mice for developing asthmatic animal models. Total serum IgE level and IFN-γ, IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). The allergenicity of the extraction was assessed using pathological sections developed from the mouse pulmonary tissues. The concentration of extract from the 60 samples was ranged from 4.37 μg/ml to 30.76 μg/ml. After analyzing with Western blot, 31 of 60 samples were positive for 4 allergens of acaroid mites, and yet 16 were negative. The levels of total IgE from serum IL-4 and IL-5 from the BALF in the experimental group were apparently higher than that of negative control and PBS group (P 0.05). However,the IFN-γ level in BALF was lower compared with the negative control and PBS group (P 0.05). The pathological changes were evidently emerged in pulmonary tissues, which were similar to those of OVA group, compared with the PBS ground and negative controls. The air-conditioner filters in human dwellings of Wuhu area potentially contain the major group allergen 1 and 2 from D. farinae and D. pteronyssinus, which may be associated with seasonal prevalence of allergic disorders in this area.

  17. Characterization of biological aerosol exposure risks from automobile air conditioning system.

    Science.gov (United States)

    Li, Jing; Li, Mingzhen; Shen, Fangxia; Zou, Zhuanglei; Yao, Maosheng; Wu, Chang-yu

    2013-09-17

    Although use of automobile air conditioning (AC) was shown to reduce in-vehicle particle levels, the characterization of its microbial aerosol exposure risks is lacking. Here, both AC and engine filter dust samples were collected from 30 automobiles in four different geographical locations in China. Biological contents (bacteria, fungi, and endotoxin) were studied using culturing, high-throughput gene sequence, and Limulus amebocyte lysate (LAL) methods. In-vehicle viable bioaerosol concentrations were directly monitored using an ultraviolet aerodynamic particle sizer (UVAPS) before and after use of AC for 5, 10, and 15 min. Regardless of locations, the vehicle AC filter dusts were found to be laden with high levels of bacteria (up to 26,150 CFU/mg), fungi (up to 1287 CFU/mg), and endotoxin (up to 5527 EU/mg). More than 400 unique bacterial species, including human opportunistic pathogens, were detected in the filter dusts. In addition, allergenic fungal species were also found abundant. Surprisingly, unexpected fluorescent peaks around 2.5 μm were observed during the first 5 min use of AC, which was attributed to the reaerosolization of those filter-borne microbial agents. The information obtained here can assist in minimizing or preventing the respiratory allergy or infection risk from the use of automobile AC system.

  18. Deinococcus multiflagellatus sp. nov., isolated from a car air-conditioning system.

    Science.gov (United States)

    Kim, Dong-Uk; Lee, Hyosun; Lee, Suyeon; Park, Sooyeon; Yoon, Jung-Hoon; Zhao, Lei; Kim, Min-Kyu; Ahn, Jae-Hyung; Ka, Jong-Ok

    2018-04-01

    A gamma radiation-resistant and pink-to-red pigmented bacterial strain, designated ID1504 T , was isolated from a car air-conditioning system sampled in Korea. The cells were observed to be Gram-stain negative, aerobic, motile with peritrichous flagella and short rod-shaped. Phylogenetically, the strain groups with the members of the genus Deinococcus and exhibits high 16S rRNA gene sequence similarities with Deinococcus arenae SA1 T (94.0%), Deinococcus actinosclerus BM2 T (93.9%) and Deinococcus soli N5 T (93.5%). The predominant fatty acids were identified as C 17:0 , C 16:0 , summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c) and iso-C 17:0 . The major respiratory quinone was identified as MK-8. The polar lipids were found to be comprised of unidentified phospholipids, unidentified glycolipids, an unidentified aminophospholipid and an unidentified lipid. The DNA G+C content of the strain was determined to be 68.3 mol%. On the basis of the phenotypic, genotypic and chemotaxonomic characteristics, strain ID1504 T should be classified in a novel species in the genus Deinococcus, for which the name Deinococcus multiflagellatus sp. nov. (= KACC 19287 T  = NBRC 112888 T ) is proposed.

  19. Study of a vapor-compression air-conditioning system for jetliners

    Energy Technology Data Exchange (ETDEWEB)

    Roeyttae, P.

    2009-07-01

    Most modern passenger aeroplanes use air cycle cooling. A high-speed air cycle is a reliable and light option, but not very efficient. This thesis presents research work done to design a novel vapour cooling cycle for aeroplanes. Due to advancements in high-speed permanent magnet motors, the vapour cycle is seen as a competitive option for the air cycle in aeroplanes. The aerospace industry placews tighter demands on the weight, reliability and environmental effects of the machinery than those met by conventional chillers, and thus modifications to conventional design are needed. The thesis is divided into four parts: the initial screening of the working fluid, 1-D design and performance values of the compressor, 1-D off-design value predictions of the compressor and the 3-D design of the compressor. The R24fa was selected as the working fluid based the study. The off-design range of the compressor was predicted to be wide and suitable for the application. The air-conditioning system developed is considerably smaller than previous designs using centrifugal compressors. (orig.)

  20. A dynamic switching strategy for air-conditioning systems operated in light-thermal-load conditions

    International Nuclear Information System (INIS)

    Lin, Jin-Long; Yeh, T.-J.; Hwang, Wei-Yang

    2009-01-01

    Recently, modern air-conditioners have begun to incorporate variable-speed compressors and variable-opening expansion valves, together with feedback control to improve the performance and energy efficiency. However, for the compressor there usually exists a low-speed limit below which its speed can not be continuously modulated unless it is completely turned off. When the air-conditioning system is operated in light-thermal-load conditions, the low-speed limit causes the compressor to run in an on-off manner which can significantly degrade the performance and efficiency. In this paper, a dynamic switching strategy is proposed for such scenarios. The strategy is basically an integration of a cascading control structure, an intuitive switching strategy, and a dynamic compensator. While the control structure provides the nominal performance, the intuitive switching strategy and the dynamic compensator together can account for the compressor's low-speed limitation. Theoretical analysis reveals that when the output matrix of the dynamic compensator is chosen properly, the proposed strategy can effectively reduce the output error caused by the on-off operation of the compressor. Experiments also demonstrate that the proposed strategy can simultaneously provide better regulation for the indoor temperature and improve the energy efficiency at steady state.

  1. Actual measurement, hygrothermal response experiment and growth prediction analysis of microbial contamination of central air conditioning system in Dalian, China.

    Science.gov (United States)

    Lv, Yang; Hu, Guangyao; Wang, Chunyang; Yuan, Wenjie; Wei, Shanshan; Gao, Jiaoqi; Wang, Boyuan; Song, Fangchao

    2017-04-03

    The microbial contamination of central air conditioning system is one of the important factors that affect the indoor air quality. Actual measurement and analysis were carried out on microbial contamination in central air conditioning system at a venue in Dalian, China. Illumina miseq method was used and three fungal samples of two units were analysed by high throughput sequencing. Results showed that the predominant fungus in air conditioning unit A and B were Candida spp. and Cladosporium spp., and two fungus were further used in the hygrothermal response experiment. Based on the data of Cladosporium in hygrothermal response experiment, this paper used the logistic equation and the Gompertz equation to fit the growth predictive model of Cladosporium genera in different temperature and relative humidity conditions, and the square root model was fitted based on the two environmental factors. In addition, the models were carried on the analysis to verify the accuracy and feasibility of the established model equation.

  2. Application of computational fluid dynamics and pedestrian-behavior simulations to the design of task-ambient air-conditioning systems of a subway station

    Energy Technology Data Exchange (ETDEWEB)

    Fukuyo, Kazuhiro [Graduate School of Innovation and Technology Management, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611 (Japan)

    2006-04-15

    The effects of task-ambient (TA) air-conditioning systems on the air-conditioning loads in a subway station and the thermal comfort of passengers were studied using computational fluid dynamics (CFD) and pedestrian-behavior simulations. The pedestrian-behavior model was applied to a standard subway station. Task areas were set up to match with crowdedness as predicted by the pedestrian-behavior simulations. Subsequently, a variety of TA air-conditioning systems were designed to selectively control the microclimate of the task areas. Their effects on the thermal environment in the station in winter were predicted by CFD. The results were compared with those of a conventional air-conditioning system and evaluated in relation to the thermal comfort of subway users and the air-conditioning loads. The comparison showed that TA air-conditioning systems improved thermal comfort and decreased air-conditioning loads. (author)

  3. Design of automatic control system of temperature in radon chamber controlled by air-condition based on 485 BUS

    International Nuclear Information System (INIS)

    Man Zaigang; Wang Renbo; Zhang Xiongjie; Zhu Zhifu; Tang Bin

    2009-01-01

    Radon chamber can be widely used in various radon measurement instruments for calibration, testing and radon environment experiment. According to requisition, radon chamber temperature should be controllable from +10 degree C to +30 degree C, and the temperature control accuracy of the system reaches ±1 degree C. The design of automatic temperature controlled by air-condition based on 485 BUS is introduced. The software and hardware techniques of how the ATMEL89S52 micro controller controls air-condition and communicates with computer are elaborated on. (authors)

  4. Energy efficient hybrid nanocomposite-based cool thermal storage air conditioning system for sustainable buildings

    International Nuclear Information System (INIS)

    Parameshwaran, R.; Kalaiselvam, S.

    2013-01-01

    The quest towards energy conservative building design is increasingly popular in recent years, which has triggered greater interests in developing energy efficient systems for space cooling in buildings. In this work, energy efficient silver–titania HiTES (hybrid nanocomposites-based cool thermal energy storage) system combined with building A/C (air conditioning) system was experimentally investigated for summer and winter design conditions. HiNPCM (hybrid nanocomposite particles embedded PCM) used as the heat storage material has exhibited 7.3–58.4% of improved thermal conductivity than at its purest state. The complete freezing time for HiNPCM was reduced by 15% which was attributed to its improved thermophysical characteristics. Experimental results suggest that the effective energy redistribution capability of HiTES system has contributed for reduction in the chiller nominal cooling capacity by 46.3% and 39.6% respectively, under part load and on-peak load operating conditions. The HiTES A/C system achieved 27.3% and 32.5% of on-peak energy savings potential in summer and winter respectively compared to the conventional A/C system. For the same operating conditions, this system yield 8.3%, 12.2% and 7.2% and 10.2% of per day average and yearly energy conservation respectively. This system can be applied for year-round space conditioning application without sacrificing energy efficiency in buildings. - Highlights: • Energy storage is acquired by HiTES (hybrid nanocomposites-thermal storage) system. • Thermal conductivity of HiNPCM (hybrid nanocomposites-PCM) was improved by 58.4%. • Freezing time of HiNPCM was reduced by 15% that enabled improved energy efficiency. • Chiller nominal capacity was reduced by 46.3% and 39.6% in on-peak and part load respectively. • HiTES A/C system achieved appreciable energy savings in the range of 8.3–12.2%

  5. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    International Nuclear Information System (INIS)

    Fleming, Evan; Wen, Shaoyi; Shi, Li; Silva, Alexandre K. da

    2013-01-01

    Highlights: • We developed an automotive thermal storage air conditioning system model. • The thermal storage unit utilizes phase change materials. • We use semi-analytic solution to the coupled phase change and forced convection. • We model the airside heat exchange using the NTU method. • The system model can incorporate dynamic inputs, e.g. variable inlet airflow. - Abstract: A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system’s dynamic behavior, such as a dynamic air flow rate into the vehicle’s cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle’s cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid–air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semi-analytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid–air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system

  6. System design and analysis of the trans-critical carbon-dioxide automotive air-conditioning system.

    Science.gov (United States)

    Mu, Jing-Yang; Chen, Jiang-Ping; Chen, Zhi-Jiu

    2003-01-01

    As an environmentally harmless and feasible alternate refrigerant, CO2 has attracted worldwide attention, especially in the area of automobile air-conditioning (AAC). The thermal property of CO2 and its trans-critical refrigeration cycle is very different from that of the traditional CFC or HCFC system. The detailed process of CO2 system thermal cycle design and optimization is described in this paper. System prototype and performance test bench were developed to analyze the performance of the CO2 AAC system.

  7. Fungal endophthalmitis caused by Paecilomyces variotii following cataract surgery: a presumed operating room air-conditioning system contamination.

    Science.gov (United States)

    Tarkkanen, Ahti; Raivio, Virpi; Anttila, Veli-Jukka; Tommila, Petri; Ralli, Reijo; Merenmies, Lauri; Immonen, Ilkka

    2004-04-01

    To report a case of delayed fungal endophthalmitis by Paecilomyces variotii following uncomplicated cataract surgery. To our knowledge this is the first reported case of postoperative endophthalmitis by this species. We report the longterm clinical follow-up of an 83-year-old female who underwent uncomplicated sutureless, small-incision cataract surgery. She developed recurring uveitis 4 months after surgery. Vitreous tap and finally complete vitrectomy with removal of the capsular bag including the intraocular lens were performed. Fungi were studied by histopathology and culture. At histopathological examination, the fungi were found to be closely related with the capsular bag. A few mononuclear inflammatory cells were encountered. At culture, Paecilomyces variotii, a common ubiquitous non-pathogenic saprophyte, was identified. Despite systemic, intravitreal and topical antifungal therapy after vitrectomy the uveitis recurred several times, but no fungal organisms were isolated from the repeat intraocular specimen. At 18 months postoperatively the subject's visual acuity was finger counting at 2 metres. At the time of surgery the operating room air-conditioning system was undergoing repairs. Cases of fungal endophthalmitis after contamination from air-conditioning ventilation systems have been reported before, but none of the cases reported have been caused by P. variotii. P. variotii, a non-pathogenic environmental saprophyte, may be disastrous if introduced into the eye. International recommendations on the environmental control of the operating room air-conditioning ventilation system should be strictly followed. No intraoperative surgery should be undertaken while the air-conditioning system is undergoing repairs or service.

  8. Solar air conditioning. Dresden colloquium; Solare Klimatisierung. Dresdner Kolloquium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Subjects: R + D activities in solar air conditioning; dessicative and evaporative cooling (DEC) - systems and components; Chances of solar air conditioning in Europe; Practical experience with solar-assisted air conditioning; Performance of a solar system at Lissabon; DEC system in the Alsenblock building, Berlin; Does solar air conditioning require specially designed buildings; Performance of solar heated adsorption refrigerators; Low-capacity absacity absorption systems for solar air conditioning. [German] Die Kolloquiumsschrift beinhaltet Unterlagen ueber die abgehandelten Themen. Sie lauten: F and E-Aktivitaeten im Bereich Solare Klimatisierung; SGK(DEC-Technik) - ausgefuehrte Anlagen und deren Komponenten; Chancen der solaren Klimatisierung in Europa; Erfahrungen mit der solarunterstuetzten Klimatisierung; Energieverbrauch und Regelung von SGK-Anlagen; Betriebserfahrungen einer Solaranlage in Lissabon; Realisierung der SGK im Alsenblock Berlin; Erfordert die solare Klimatisierung besondere Gebaeude?; Betriebserfahrungen mit solar beheizten Adsorptionskaeltemaschinen; Absorptionsanlagen kleiner Leistung fuer solare Klimatisierung. (orig.)

  9. Sterilization efficacy of ultraviolet irradiation on microbial aerosols under dynamic airflow by experimental air conditioning systems

    International Nuclear Information System (INIS)

    Nakamura, Hiroshi

    1987-01-01

    In order to know the sterilization efficacy of ultraviolet irradiation on microbial aerosols, the size and the weight of the aerosol particles were evaluated, and these were irradiated under dynamic air flow created by an experimental air conditioning system. The experimental apparatus consisted of a high efficiency particulate air (HEPA) filter, an aerosol generator, spiral UV lamps placed around a quart glass tube, an Andersen air sampler and a vacuum pump. They were connected serially by stainless steel ducts (85 mm in diameter, 8 m in length). Six types of microbial aerosols generated from an ultrasonic nebulizer were irradiated by UV rays (wavelength 254 nm, mean density 9400 μW/cm 2 ). Their irradiation time ranged from 1.0 to 0.0625 seconds. The microbial aerosols were collected onto the trypticase soy agar (TSA) medium in the Andersen air sampler. After incubation, the number of colony forming units (CFU) were counted, and converted to particle counts. The diameter of microbial aerosol particles calculated by their log normal distribution were found to match the diameter of a single bacteria cell measured by a microscope. The sterilization efficacy of UV in standard airflow conditions (0.5 sec. irradiation) were found to be over 99.5 % in Staphylococcus aureus, Staphylococcus epidermidis, Serratia marcescens, Bacillus subtilis (vegetative cell) and Bacillus subtilis (spore) and 67 % in Aspergillus niger (conidium). In A. niger, which was the most resistant microbe to UV irradiation, the efficacy rose up to 79 % when irradiated for 1.0 sec., and it was observed that the growth speed of the colonies was slower than that of the controls. It was thought that UV rays caused some damage to the proliferation of A. niger cells. (author)

  10. Flavisolibacter carri sp. nov., isolated from an automotive air-conditioning system.

    Science.gov (United States)

    Lee, Hyosun; Kim, Dong-Uk; Lee, Suyeon; Kim, Song-Gun; Park, A-Young; Ahn, Jae-Hyung; Ka, Jong-Ok

    2018-04-18

    A Gram-stain negative, aerobic, non-motile, rod-shaped and yellow bacterium, designated TX0651 T , was isolated from an automotive air-conditioning system. Phylogenetically, the strain groups with the members of the genus Flavisolibacter and exhibits high 16S rRNA gene sequence similarities with Flavisolibacter ginsenosidimutans Gsoil 636 T (97.4%), Flavisolibacter ginsengiterrae Gsoil 492 T (96.3%) and Flavisolibacter ginsengisoli Gsoil 643 T (96.2%). DNA-DNA relatedness between TX0651 T and F. ginsenosidimutans KCTC 22818 T and F. ginsengiterrae KCTC 12656 T were determined to be less than 40%. The low levels of DNA-DNA relatedness identifies the strain TX0651 T as a novel species in the genus Flavisolibacter. The major cellular fatty acids were identified as iso-C 15:0 , summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c), iso-C 15:1 G and iso-C 17:0 3-OH. The predominant respiratory quinone was identified as MK-7. The polar lipids were found to be comprised of phosphatidylethanolamine, unidentified amino-glycophospholipids, an unidentified aminophospholipid, an unidentified amino lipid and unidentified lipids. The DNA G+C content of the strain was determined to be 31.2 mol%. On the basis of the phenotypic, genotypic and chemotaxonomic characteristics, strain TX0651 T should be classified in a novel species in the genus Flavisolibacter, for which the name Flavisolibacter carri sp. nov. (= KACC 19014 T  = KCTC 52836 T  = NBRC 111784 T ) is proposed.

  11. Roseomonas aeriglobus sp. nov., isolated from an air-conditioning system.

    Science.gov (United States)

    Lee, Yunho; Jeon, Che Ok

    2018-03-01

    A novel pale pink-coloured, strictly aerobic, Gram-stain negative bacterial strain, designated strain KER25-12 T , was isolated from a laboratory air-conditioning system in South Korea. Cells were observed to be non-motile cocci showing positive catalase and oxidase reactions. Strain KER25-12 T was found to grow at 10-30 °C (optimum, 25-30 °C), at pH 4.0-9.0 (optimum, pH 6.0-7.0) and in the presence of 0-2% (w/v) NaCl (optimum, 0%). Ubiquinone-10 and spermidine were detected as the sole respiratory quinone and the predominant polyamine, respectively. The major fatty acids were identified as summed feature 8 (comprising C 18:1 ω7c and/or C 18:1 ω6c), summed feature 3 (comprising C 16:1 ω7c and/or C 16:1 ω6c), C 16:0 and C 18:0 . The genomic DNA G+C content of strain KER25-12 T was determined to be 70.0 mol%. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified aminolipid. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain KER25-12 T belongs to the genus Roseomonas and shows high sequence similarity to Roseomonas aerilata 5420S-30 T (98.57%), Roseomonas pecuniae N75 T (97.44%) and Roseomonas vinacea CPCC 100056 T (97.40%). Based on the morphological, physiological, chemotaxonomic and phylogenetic features, strain KER25-12 T is concluded to represent a novel species of the genus Roseomonas, for which the name Roseomonas aeriglobus sp. nov. is proposed. The type strain is KER25-12 T (= KACC 19282 T  = JCM 32049 T ).

  12. Spirosoma metallilatum sp. nov., isolated from an automotive air conditioning system.

    Science.gov (United States)

    Kim, Dong-Uk; Lee, Hyosun; Lee, Suyeon; Park, Sooyeon; Yoon, Jung-Hoon; Ka, Jong-Ok

    2018-02-01

    A Gram-stain-negative, aerobic, rod-shaped and yellow-pigmented bacterial strain, designated TX0405 T , was isolated from an automotive air conditioning system. Colonies were circular, convex, semi-translucent, smooth and yellow. The strain grew at 20-28°C (optimum, 28°C), at pH 6.0-7.5 (optimum, pH 6.5) and in the presence of 0-1 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence indicated that the strain was grouped with the members of the genus Spirosoma, with the sequence similarities of 93.0 and 92.3 % with Spirosoma panaciterrae DSM 21099 T and Spirosoma swuense JBM2-3 T , respectively. The major fatty acids of the strain were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (33.2 %), C16 : 1ω5c (25.4 %), iso-C15 : 0 (15.0 %), C16 : 0 (6.5 %) and iso-C17 : 0 3-OH (6.2 %). The predominant menaquinone was MK-7. The polar lipids were phosphatidylethanolamine, an unidentified aminolipid, two unidentified aminophospholipids and three unidentified lipids. The DNA G+C content of the type strain was 51.9 mol%. On the basis of the data presented, strain TX0405 T represents a novel species of the genus Spirosoma, for which the name Spirosomametallilatum sp. nov. (=KACC 19012 T =NBRC 112493 T ) is proposed.

  13. A Novel Distributed Economic Model Predictive Control Approach for Building Air-Conditioning Systems in Microgrids

    Directory of Open Access Journals (Sweden)

    Xinan Zhang

    2018-04-01

    Full Text Available With the penetration of grid-connected renewable energy generation, microgrids are facing stability and power quality problems caused by renewable intermittency. To alleviate such problems, demand side management (DSM of responsive loads, such as building air-conditioning system (BACS, has been proposed and studied. In recent years, numerous control approaches have been published for proper management of single BACS. The majority of these approaches focus on either the control of BACS for attenuating power fluctuations in the grid or the operating cost minimization on behalf of the residents. These two control objectives are paramount for BACS control in microgrids and can be conflicting. As such, they should be considered together in control design. As individual buildings may have different owners/residents, it is natural to control different BACSs in an autonomous and self-interested manner to minimize the operational costs for the owners/residents. Unfortunately, such “selfish” operation can result in abrupt and large power fluctuations at the point of common coupling (PCC of the microgrid due to lack of coordination. Consequently, the original objective of mitigating power fluctuations generated by renewable intermittency cannot be achieved. To minimize the operating costs of individual BACSs and simultaneously ensure desirable overall power flow at PCC, this paper proposes a novel distributed control framework based on the dissipativity theory. The proposed method achieves the objective of renewable intermittency mitigation through proper coordination of distributed BACS controllers and is scalable and computationally efficient. Simulation studies are carried out to illustrate the efficacy of the proposed control framework.

  14. Simplified model-based optimal control of VAV air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Nassif, N.; Kajl, S.; Sabourin, R. [Ecole de Technologie Superieure, Montreal, PQ (Canada). Dept. of Construction Engineering

    2005-07-01

    The improvement of Variable Air Volume (VAV) system performance is one of several attempts being made to minimize the high energy use associated with the operation of heating, ventilation and air conditioning (HVAC) systems. A Simplified Optimization Process (SOP) comprised of controller set point strategies and a simplified VAV model was presented in this paper. The aim of the SOP was to determine supply set points. The advantage of the SOP over previous methods was that it did not require a detailed VAV model and optimization program. In addition, the monitored data for representative local-loop control can be checked on-line, after which controller set points can be updated in order to ensure proper operation by opting for real situations with minimum energy use. The SOP was validated using existing monitoring data and a model of an existing VAV system. Energy use simulations were compared to that of the existing VAV system. At each simulation step, 3 controller set point values were proposed and studied using the VAV model in order to select a value for each point which corresponded to the best performance of the VAV system. Simplified VAV component models were presented. Strategies for controller set points were described, including zone air temperature, duct static pressure set points; chilled water supply set points and supply air temperature set points. Simplified optimization process calculations were presented. Results indicated that the SOP provided significant energy savings when applied to specific AHU systems. In a comparison with a Detailed Optimization Process (DOP), the SOP was capable of determining set points close to those obtained by the DOP. However, it was noted that the controller set points determined by the SOP need a certain amount of time to reach optimal values when outdoor conditions or thermal loads are significantly changed. It was suggested that this disadvantage could be overcome by the use of a dynamic incremental value, which

  15. Energy problems of the central systems of air conditioning; Problemas energeticos de los sistemas centrales de climatizacion

    Energy Technology Data Exchange (ETDEWEB)

    Cardero Corria, Gaspar [Cubanacan, S.A., Varadero (Cuba)

    2003-07-01

    The central systems of air conditioning are widely used in air conditioning production for several reasons among which excel: 1) Better aesthetic of the building, 2) Less noise in the air conditioning premises and 3) Greater yield of the consumed energy. This is indeed the third reason in which this paper will try to contribute with elements that will allow reveal the problem and to identify some possible causes that originate it. The centralized systems of air conditioning must produce conditioned air with lesser power cost than the individual systems, it is that saving which allows to recover an investment that normally surpasses them in 3 to 5 times. Nevertheless, the real numbers do not demonstrate that. [Spanish] Los sistemas centrales de climatizacion son ampliamente usados en la produccion de aire acondicionado por varias razones entre las que sobresalen: 1) Mejor estetica del edificio, 2) Menor ruido en los locales climatizados y 3) Mayor rendimiento de la energia consumida. Es precisamente la tercera razon en la cual este trabajo intentara aportar elementos que permitan develar el problema e identificar algunas posibles causas que lo originan. Los sistemas centralizados de climatizacion deben producir aire acondicionado con un menor gasto energetico que los sistemas individuales, es precisamente ese ahorro lo que permite recuperar una inversion que normalmente los supera en 3 a 5 veces. Sin embargo, los numeros reales no demuestran eso.

  16. Assessment of indoor air quality in comparison using air conditioning and fan system in printing premise

    Directory of Open Access Journals (Sweden)

    Ramlan Nazirah

    2017-01-01

    Full Text Available Printers contribute to various emissions consist with chemical contaminants. High concentration of the particulate matter can cause serious health problems. This study focuses on the indoor air quality in printing premise unit in Universiti Tun Hussein Onn, Malaysia. Field testing involving air sampling methods were taken from 900 hours to 1600 hours, for every 30 minutes using physical measurement which is Multi-Channel Air Quality Monitor (YESAIR, E-Sampler and Ozone Meter. Air sampling was recorded based on one sampling point and most suitable point for production. A comparison based on different ventilation using fan and air-conditioning were also taken and results is being compared based on OSHA and NIOSH standards. Besides that, the statistical analysis is being conducted in order to predict the effect on number of printers. From the result, the O3 concentrations show, 10% reduced for printing premise using fan ventilation compared to air-conditioning but remain the same value for PM2.5. The concentration of O3 increased when the number of printers decreased, while the concentration of PM2.5 increased the increase of printers number. Overall, the use of fan in printing premise is more suggested since the level is slightly lower than the printing premise using air-conditioning.

  17. Simulation of Evacuated Tube Collector and Storage of Hybrid Air-conditioning System

    Directory of Open Access Journals (Sweden)

    Mustafa Ahmed Abdulhussain

    2018-02-01

    Full Text Available The CFD transient simulation of superheating the refrigerant R410 through the heat exchange with the evacuated tube water heating system of the hybrid split air conditioner that is subjected to solar radiation of constant intensity with the contribution of fan accelerated air is performed by the ANSYS-CFX code. The comparison with experimental work showed a minimum percentage error 8% of the predicted refrigerant evaporative heat transfer with storage tank horizontal tubing. In addition, the results denoted high absorption rate for the evacuated tubes, reducing highly reversed heat transmission for the circulated water. 

  18. A novel capacity controller for a three-evaporator air conditioning (TEAC) system for improved indoor humidity control

    International Nuclear Information System (INIS)

    Yan, Huaxia; Deng, Shiming; Chan, Ming-yin

    2016-01-01

    Highlights: • A novel capacity controller for TEAC systems for improved indoor humidity control is developed. • The novel controller was developed by integrating two previous control algorithms. • Experimental controllability tests were carried out. • Improved control over indoor humidity levels and higher energy efficiency can be achieved. - Abstract: Using a multi-evaporator air conditioning (MEAC) system to correctly control indoor air temperatures only in a multi-room application is already a challenging and difficult task, let alone the control of both indoor air temperature and humidity. This is because in an MEAC system, a number of indoor units are connected to a common condensing unit. Hence, the interferences among operation parameters of different indoor units would make the desired control of an MEAC system hard to realize. Limited capacity control algorithms for MEAC systems have been developed, with most of them focusing only on the control of indoor air temperature, and no previous studies involving control of indoor air humidity using MEAC systems can be identified. In this paper, the development of a novel capacity controller for a three-evaporator air conditioning (TEAC) system for improved indoor air humidity control is reported. The novel controller was developed by integrating two previous control algorithms for a dual-evaporator air conditioning system for temperature control and for a single-evaporator air conditioning system for improved indoor humidity control. Experimental controllability tests were carried out and the controllability test results showed that, with the novel controller, improved control over indoor humidity levels and better energy efficiency for a TEAC system could be obtained as compared to the traditional On–Off controllers extensively used by MEAC systems.

  19. Ventilation and air conditioning systems in maritime productions units; Panorama dos sistemas de VAC em unidades maritimas de producao

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Fernando Pedrosa; Sztajnbok, Ernani Luis [PETROBRAS, Rio de Janeiro, RJ (Brazil); Padua, Carlos Eduardo Dantas de; Passos, Alfredo Silveira [DUOVAC Engenharia Ltda. (Brazil)

    2004-07-01

    In an Offshore Stationary Production Unit (SPU), the adequate project of the Ventilation and Air Conditioning (VAC) System is not only a thermal comfort requirement but part of the essential safety services of the installation and complement for area classification requirements associated with electrical equipment. The VAC installations are sometimes the object of complaints by onboard team. Problems such as unsatisfactory system performance, high noise levels in the accommodation quarters, offices and other areas and the discomfort caused by unbalanced ventilation and air conditioning systems, are some of the most frequent complaints. Air Conditioning systems are classified as Direct and Indirect Expansion. Decentralized systems with Indirect Expansion has been adopted in PETROBRAS projects. This conception is not used in VAC Systems for platforms installed in North Sea, where the use of Centralized Systems with Direct Expansion are more common. The objective of this work is to compare the VAC conception projects, analyzing their advantages and disadvantages . The evaluation of VAC System in PETROBRAS project, and their steps in SPU development, is also scope of this paper. (author)

  20. Utilisation of an Air-conditioning System to Control the Levels of Radon and Radon Progeny in a Workplace Environment

    International Nuclear Information System (INIS)

    Marley, F.

    2000-01-01

    From long-term real-time radon and radon progeny measurements taken in a relatively large retail store, cyclical patterns were evident, which were found to relate to the overriding influence of the timed air-conditioning system. Concentration of radon, radon progeny and the variability of F factor were found to depend significantly on the intermittent operation of this ventilation-air-conditioning system. After pressure equalisation remedial measures proved ineffective, the air-movement system was utilised to reduce the levels of radon and radon progeny to well within established norms applicable during working hours. It is demonstrated that the average levels for radon and radon progeny are reduced in absolute terms. This amounted to less than 12% of the general level, during designated work periods. Where air movement systems are already installed, as well as other circumstances, their regulation provides an economical solution to meeting legal and other standards for radon in the workplace. (author)

  1. Energy Conversion and Transmission Characteristics Analysis of Ice Storage Air Conditioning System Driven by Distributed Photovoltaic Energy System

    Directory of Open Access Journals (Sweden)

    Yongfeng Xu

    2016-01-01

    Full Text Available In order to reduce the investment and operation cost of distributed PV energy system, ice storage technology was introduced to substitute batteries for solar energy storage. Firstly, the ice storage air conditioning system (ISACS driven by distributed photovoltaic energy system (DPES was proposed and the feasibility studies have been investigated in this paper. And then, the theoretical model has been established and experimental work has been done to analyze the energy coupling and transferring characteristics in light-electricity-cold conversion process. In addition, the structure optimization analysis was investigated. Results revealed that energy losses were high in ice making process of ice slide maker with only 17.38% energy utilization efficiency and the energy efficiency and exergy efficiency of ISACS driven by DPES were 5.44% and 67.30%, respectively. So the immersed evaporator and cointegrated exchanger were adopted for higher energy utilization efficiency and better financial rewards in structure optimization. The COP and exergy efficiency of ice maker can be increased to 1.48 and 81.24%, respectively, after optimization and the energy utilization efficiency of ISACS driven by DPES could be improved 2.88 times. Moreover, ISACS has the out-of-the-box function of ordinary air conditioning system. In conclusion, ISACS driven by DPES will have good application prospects in tropical regions without power grid.

  2. Field Study on Humidification Performance of a Desiccant Air-Conditioning System Combined with a Heat Pump

    Directory of Open Access Journals (Sweden)

    Koichi Kawamoto

    2016-01-01

    Full Text Available A desiccant air-conditioning system was developed as a latent-load-processing air conditioner in a dedicated outdoor air system during the summer. This study investigated the application of this air-conditioning system to humidification during the winter without using make-up water, thereby eliminating the cause of microbial contamination in air-conditioning systems. The experiments were conducted with a system used for summer applications to determine the feasibility of adsorbing vapor from outdoor air and supplying it to an indoor space. The humidification performance, energy efficiency, and operating conditions were examined. Although the conditions were subpar because the experiments were performed with an actual dedicated outdoor air system, the results showed that it is possible to supply air with a minimum humidity ratio of 5.8 g/kg dry air (DA when the humidity ratio of outdoor air ranges from 1.8 to 2.3 g/kg DA. The minimum humidification performance required for a dedicated outdoor air system was achieved by increasing the airflow rate of the moisture-adsorption side to 2–3 times that of the humidification side. In addition, air leaking from the moisture-adsorption side to the humidification side, improving the mechanical structure, such as by the insulation of the moisture-adsorption side, and an efficient operating method were examined for humidification during the winter.

  3. Operation of a cascade air conditioning system with two-phase loop

    Science.gov (United States)

    Feng, Yinshan; Wang, Jinliang; Zhao, Futao; Verma, Parmesh; Radcliff, Thomas D.

    2018-05-29

    A method of operating a heat transfer system includes starting operation of a first heat transfer fluid vapor/compression circulation loop including a fluid pumping mechanism, a heat exchanger for rejecting thermal energy from a first heat transfer fluid, and a heat absorption side of an internal heat exchanger. A first conduit in a closed fluid circulation loop circulates the first heat transfer fluid therethrough. Operation of a second two-phase heat transfer fluid circulation loop is started after starting operation of the first heat transfer fluid circulation loop. The second heat transfer fluid circulation loop transfers heat to the first heat transfer fluid circulation loop through the internal heat exchanger and includes a heat rejection side of the internal heat exchanger, a liquid pump, and a heat exchanger evaporator. A second conduit in a closed fluid circulation loop circulates a second heat transfer fluid therethrough.

  4. Simulation of absorption refrigeration system for automobile application

    Directory of Open Access Journals (Sweden)

    Ramanathan Anand

    2008-01-01

    Full Text Available An automotive air-conditioning system based on absorption refrigeration cycle has been simulated. This waste heat driven vapor absorption refrigeration system is one alternate to the currently used vapour compression refrigeration system for automotive air-conditioning. Performance analysis of vapor absorption refrigeration system has been done by developing a steady-state simulation model to find the limitation of the proposed system. The water-lithium bromide pair is used as a working mixture for its favorable thermodynamic and transport properties compared to the conventional refrigerants utilized in vapor compression refrigeration applications. The pump power required for the proposed vapor absorption refrigeration system was found lesser than the power required to operate the compressor used in the conventional vapor compression refrigeration system. A possible arrangement of the absorption system for automobile application is proposed.

  5. Experimental research on the indoor temperature and humidity fields in radiant ceiling air-conditioning system under natural ventilation

    Science.gov (United States)

    Huang, Tao; Xiang, Yutong; Wang, Yonghong

    2017-05-01

    In this paper, the indoor temperature and humidity fields of the air in a metal ceiling radiant panel air conditioning system with fresh air under natural ventilation were researched. The temperature and humidity distributions at different height and different position were compared. Through the computation analysis of partial pressure of water vapor, the self-recovery characteristics of humidity after the natural ventilation was discussed.

  6. Thermotechnical comparison of possible operation variants for air conditioning system of mine air with high pressure heat exchanger and hydrodistributor

    OpenAIRE

    Korsun, F. O.

    2015-01-01

    Problem. There are vast losses of cold that take place during the transition of cold to deep horizons of shafts by the mine air conditioning system (MASC) with high pressure heat exchanger. Cold is transferred by the recuperative way. Vast losses of cold mean vast losses of electricity to in order to supply it. Any enterprise requires the reduction of electricity consumption. This article gives proposals on how to replace HPHE into hydrodistributor which will considerably reduce cold losses. ...

  7. [Assessment of the air quality improment of cleaning and disinfection on central air-conditioning ventilation system].

    Science.gov (United States)

    Liu, Hongliang; Zhang, Lei; Feng, Lihong; Wang, Fei; Xue, Zhiming

    2009-09-01

    To assess the effect of air quality of cleaning and disinfection on central air-conditioning ventilation systems. 102 air-conditioning ventilation systems in 46 public facilities were sampled and investigated based on Hygienic assessment criterion of cleaning and disinfection of public central air-conditioning systems. Median dust volume decreased from 41.8 g/m2 to 0.4 g/m2, and the percentage of pipes meeting the national standard for dust decreased from 17.3% (13/60) to 100% (62/62). In the dust, median aerobic bacterial count decreased from 14 cfu/cm2 to 1 cfu/cm2. Median aerobic fungus count decreased from 10 cfu/cm2 to 0 cfu/cm2. The percentage of pipes with bacterial and fungus counts meeting the national standard increased from 92.4% (171/185) and 82.2% (152/185) to 99.4% (165/166) and 100% (166/166), respectively. In the ventilation air, median aerobic bacterial count decreased from 756 cfu/m3 to 229 cfu/m3. Median aerobic fungus count decreased from 382 cfu/m3 to 120 cfu/m3. The percentage of pipes meeting the national standard for ventilation air increased from 33.3% (81/243) and 62.1% (151/243) to 79.8% (292/366) and 87.7% (242/276), respectively. But PM10 rose from 0.060 mg/m3 to 0.068 mg/m3, and the percentage of pipes meeting the national standard for PM10 increased from 74.2% (13/60) to 90.2% (46/51). The cleaning and disinfection of central air-conditioning ventilation systems could have a beneficial effect of air quality.

  8. Control of systems with costs related to switching: applications to air-condition systems

    DEFF Research Database (Denmark)

    Thybo (Deng), Honglian; Larsen, Lars Finn Sloth; Stoustrup, Jakob

    2009-01-01

    The objective of this paper is to investigate a low complexity method for controlling systems with binary inputs that have costs related to switching. The control objective for this type of systems is often a trade off between the deviation from the reference and the number of switches (weariness...... energy efficiency etc.). For such systems a steady state solution might never be attained, but rather the optimal behavior might be constituted by a limit cycle. In this paper we consider the problem of finding and controlling the system towards an optimal limit cycle. A low complexity approach giving...

  9. FFTF primary heat transport system heating, ventilating and air conditioning system experience

    International Nuclear Information System (INIS)

    Umek, A.M.; Hicks, D.F.; Schweiger, D.L.

    1981-01-01

    FFTF cools its primary/in-containment sodium equipment cells by means of a forced nitrogen cooling system which exchanges heat with a water-glycol system. The nitrogen cooling system is also used to maintain an inert gas atmosphere in the cells containing sodium equipment. Sodium Piping and Components have installed electrical resistance heaters to maintain a minimum sodium temperature and stainless steel jacketed mineral insulation to reduce heat loss. Design features and test results of a comprehensive redesign of the HVAC and insulation system required to support long-term nuclear operations are discussed

  10. Effects of anthropogenic heat due to air-conditioning systems on an extreme high temperature event in Hong Kong

    Science.gov (United States)

    Wang, Y.; Li, Y.; Di Sabatino, S.; Martilli, A.; Chan, P. W.

    2018-03-01

    Anthropogenic heat flux is the heat generated by human activities in the urban canopy layer, which is considered the main contributor to the urban heat island (UHI). The UHI can in turn increase the use and energy consumption of air-conditioning systems. In this study, two effective methods for water-cooling air-conditioning systems in non-domestic areas, including the direct cooling system and central piped cooling towers (CPCTs), are physically based, parameterized, and implemented in a weather research and forecasting model at the city scale of Hong Kong. An extreme high temperature event (June 23-28, 2016) in the urban areas was examined, and we assessed the effects on the surface thermal environment, the interaction of sea-land breeze circulation and urban heat island circulation, boundary layer dynamics, and a possible reduction of energy consumption. The results showed that both water-cooled air-conditioning systems could reduce the 2 m air temperature by around 0.5 °C-0.8 °C during the daytime, and around 1.5 °C around 7:00-8:00 pm when the planetary boundary layer (PBL) height was confined to a few hundred meters. The CPCT contributed around 80%-90% latent heat flux and significantly increased the water vapor mixing ratio in the atmosphere by around 0.29 g kg-1 on average. The implementation of the two alternative air-conditioning systems could modify the heat and momentum of turbulence, which inhibited the evolution of the PBL height (a reduction of 100-150 m), reduced the vertical mixing, presented lower horizontal wind speed and buoyant production of turbulent kinetic energy, and reduced the strength of sea breeze and UHI circulation, which in turn affected the removal of air pollutants. Moreover, the two alternative air-conditioning systems could significantly reduce the energy consumption by around 30% during extreme high temperature events. The results of this study suggest potential UHI mitigation strategies and can be extended to

  11. Characteristic Evaluation on the Cooling Performance of an Electrical Air Conditioning System Using R744 for a Fuel Cell Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee

    2012-05-01

    Full Text Available The objective of this study was to investigate the cooling performance characteristics of an electrical air conditioning system using R744 as an alternative of R-134a for a fuel cell electric vehicle. In order to analyze the cooling performance characteristics of the air conditioning system using R744 for a fuel cell electric vehicle, an electrical air conditioning system using R744 was developed and tested under various operating conditions according to both inlet air conditions of the gas cooler and evaporator and compressor speed. The cooling capacity and coefficient of performance (COP forcooling of the tested air conditioning system were up to 6.4 kW and 2.5, respectively. In addition, the electrical air conditioning system with R744 using an inverter driven compressor showed better performance than the conventional air conditioning system with R-134a under the same operating conditions. The observed cooling performance of the developed electrical air conditioning system was found to be sufficient for cooling loads under various real driving conditions for a fuel cell electric vehicle.

  12. A Study of Demand Response Effect of Thermal Storage Air-Conditioning Systems in Consideration of Electricity Market Prices

    Science.gov (United States)

    Omagari, Yuko; Sugihara, Hideharu; Tsuji, Kiichiro

    This paper evaluates the economic impact of the introduction of customer-owned Thermal Storage Air-conditioning (TSA) systems, in an electricity market, from the viewpoint of the load service entity. We perform simulations on the condition that several thousand customers install TSA systems and shift peak demand in an electricity market by one percent. Our numerical results indicate that the purchase cost of the LSE was reduced through load management of customers with TSA systems. The introduction of TSA systems also reduced the volatility of market clearing price and reduced the whole-trade cost in an electricity market.

  13. Investigation of design method for air-conditioning system using CAE; CAE wo mochiita kucho haifu yosoku no ichikosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, M; Miyake, N; Takeuchi, T; Kori, I [Mitsubishi Motors Corp., Tokyo (Japan)

    1997-10-01

    Designing the air-conditioning system, the distributions of the flow rate and the temperature at each air outlet are important factors. This paper describes the prediction method using CFD (Computational Fluid Dynamics), which is based on the `{kappa}-{epsilon} turbulence model` and unstructured grid system. It is proved that conventional tetrahedral grid system gives adequate results for the flow rate prediction. However, it is also found that improvement is required for the thermal prediction. At the result, we suggested that the `prism mesh`, which has been developed for detailed calculation of the boundary layer properties, is essential for such the heat transfer problem. 4 refs., 13 figs.

  14. The Research on Programmable Control System of Lithium-Bromide Absorption Refrigerating Air Conditioner Based on the Network

    Directory of Open Access Journals (Sweden)

    Sun Lunan

    2016-01-01

    Full Text Available This article regard the solar lithium-bromide absorption refrigerating air conditioning system as the research object, and it was conducting adequate research of the working principle of lithium bromide absorption refrigerating machine, also it was analyzing the requirements of control system about solar energy air conditioning. Then the solar energy air conditioning control system was designed based on PLC, this system was given priority to field bus control system, and the remote monitoring is complementary, which was combining the network remote monitoring technology. So that it realized the automatic control and intelligent control of new lithium bromide absorption refrigerating air conditioning system with solar energy, also, it ensured the control system can automatically detect and adjust when the external conditions was random changing, to make air conditioning work effectively and steadily, ultimately ,it has great research significance to research the air conditioning control system with solar energy.

  15. Experimental study of the behavior of a hybrid ejector-based air-conditioning system with R134a

    International Nuclear Information System (INIS)

    Wang, Hao; Cai, Wenjian; Wang, Youyi; Yan, Jia; Wang, Lei

    2016-01-01

    Highlights: • We conduct experiment on two working mode of system and compare their performance. • We examine the influence of different pressure on system performance. • We examine the area ratio effect on ejector performance. • The system is sensitive to evaporating and generating pressure. • The COP improvement is around 34% under hybrid mode. - Abstract: A hybrid ejector-based air-conditioning system which combines a vapor compression cycle and a ejector refrigeration cycle was developed. The waste heat energy from automobile is applied as driven source towards ejector refrigeration cycle. Two ejectors with different mixing chamber diameters are applied separately for performance test and the system is operated under different working modes. The effect of generating, condensing and evaporating pressure on system performance are studied experimentally. The effect of ejector geometry parameters on ejector performance is also investigated. The performance comparison between two working modes is made and the results indicate that (1) the performance of proposed system is sensitive to the three pressures; (2) the coefficient of performance (COP) of hybrid ejector-based air-conditioning system is around 34% higher than that of conventional compressor based system which implies a potential energy saving ability of proposed hybrid system.

  16. Open air-vapor compression refrigeration system for air conditioning and hot water cooled by cool water

    International Nuclear Information System (INIS)

    Hou Shaobo; Li Huacong; Zhang Hefei

    2007-01-01

    This paper presents an open air-vapor compression refrigeration system for air conditioning and hot water cooled by cool water and proves its feasibility through performance simulation. Pinch technology is used in analysis of heat exchange in the surface heat exchanger, and the temperature difference at the pinch point is selected as 6 o C. Its refrigeration depends mainly on both air and vapor, more efficient than a conventional air cycle, and the use of turbo-machinery makes this possible. This system could use the cool in the cool water, which could not be used to cool air directly. Also, the heat rejected from this system could be used to heat cool water to 33-40 o C. The sensitivity analysis of COP to η c and η t and the simulated results T 4 , T 7 , T 8 , q 1 , q 2 and W m of the cycle are given. The simulations show that the COP of this system depends mainly on T 7 , η c and η t and varies with T 3 or T wet and that this cycle is feasible in some regions, although the COP is sensitive to the efficiencies of the axial compressor and turbine. The optimum pressure ratio in this system could be lower, and this results in a fewer number of stages of the axial compressor. Adjusting the rotation speed of the axial compressor can easily control the pressure ratio, mass flow rate and the refrigerating capacity. The adoption of this cycle will make the air conditioned room more comfortable and reduce the initial investment cost because of the obtained very low temperature air. Humid air is a perfect working fluid for central air conditioning and no cost to the user. The system is more efficient because of using cool water to cool the air before the turbine. In addition, pinch technology is a good method to analyze the wet air heat exchange with water

  17. Experimental investigation of hydrocarbon mixtures to replace HFC-134a in an automotive air conditioning system

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Kamboon, Amnouy; Orachon, Banchob

    2006-01-01

    This paper presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in automotive air conditioners. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). The measured data are obtained from an automotive air conditioning test facility utilizing HFC-134a as the refrigerant. The air conditioner, with a capacity of 3.5 kW driven by a Diesel engine, is charged and tested with four different ratios of hydrocarbon mixtures. The experiments are conducted at the same surrounding conditions. The temperature and pressure of the refrigerant at every major position in the refrigerant loop, the temperature, flow rate and humidity of air, torque and engine speed are recorded and analyzed. The parameters investigated are the refrigeration capacity, the compressor power and the coefficient of performance (COP). The results show that propane/butane/isobutane: 50%/40%/10% is the most appropriate alternative refrigerant to replace HFC-134a, having the best performance of all the hydrocarbon mixtures investigated

  18. A computational study on the performance of a solar air-conditioning system with a partitioned storage tank

    International Nuclear Information System (INIS)

    Li, Z.F.; Sumathy, K.

    2003-01-01

    This paper reports the performance of a modified solar powered air-conditioning system, which is integrated with a partitioned storage tank. In addition, the effect of two main parameters that influence the system performance is presented and discussed. The study shows that by partitioning the storage tank, the solar cooling effect can be realized much earlier and could attain a total solar cooling COP of 12% higher compared to the conventional whole-tank mode. Simulation results also indicate that there exists an optimum ratio of storage tank volume over collector area

  19. Integrated systems and modules for engine cooling and vehicle air-conditioning; Integrierte Systeme und Module zur Motorkuehlung und Innenraumklimatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, M.; Kern, J.; Kampf, H. [Behr GmbH (Germany)

    1998-12-01

    The high level of function and quality achieved today in modern vehicles cannot be simply increased by the isolated development of advanced single components alone. By contrast, the holistic optimization of systems opens up new potential. Modern cooling modules and integrated HVAC systems by Behr GmbH and Co. combine several components to form a single compact module whose integrated parts are perfectly matched to each other. Developing complete cockpits at such a high level of integration is another step towards advancing the system concept. Understanding a holistic system allows engineers to develop concepts for an efficient thermal management in the cooling system and to improve ecological compatibility of the vehicle air-conditioning system by using suitable simulation tools. (orig.) [Deutsch] Die gesamtheitliche Optimierung von Systemen eroeffnet neue Potentiale in der Automobilentwicklung. Moderne Kuehlmodule und integrierte Heiz-/Klimageraete der Behr GmbH and Co. fassen zahlreiche Komponenten zu einem kompakten Modul zusammen, dessen Einzelteile aufeinander abgestimmt sind. Die Entwicklung vollstaendiger Cockpits mit einem hohen Integrationsgrad fuehrt den Systemgedanken konsequent weiter. Das Verstaendnis des gesamten Systems erlaubt im Verbund mit geeigneten Simulationswerkzeugen die Entwicklung von Konzepten fuer ein effizientes Thermomanagement im Kuehlsystem und fuer die Verbesserung der Umweltvertraeglichkeit der Kaelteanlage. (orig.)

  20. Absorption heat pump system

    Science.gov (United States)

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  1. Novel activity classification and occupancy estimation methods for intelligent HVAC (heating, ventilation and air conditioning) systems

    International Nuclear Information System (INIS)

    Rana, Rajib; Kusy, Brano; Wall, Josh; Hu, Wen

    2015-01-01

    Reductions in HVAC (heating, ventilation and air conditioning) energy consumption can be achieved by limiting heating in the winter or cooling in the summer. However, the resulting low thermal comfort of building occupants may lead to an override of the HVAC control, which revokes its original purpose. This has led to an increased interest in modeling and real-time tracking of location, activity, and thermal comfort of building occupants for HVAC energy management. While thermal comfort is well understood, it is difficult to measure in real-time environments where user context changes dynamically. Encouragingly, plethora of sensors available on smartphone unleashes the opportunity to measure user contexts in real-time. An important contextual information for measuring thermal comfort is Metabolism rate, which changes based on current physical activities. To measure physical activity, we develop an activity classifier, which achieves 10% higher accuracy compared to Support Vector Machine and k-Nearest Neighbor. Office occupancy is another contextual information for energy-efficient HVAC control. Most of the phone based occupancy estimation techniques will fail to determine occupancy when phones are left at desk while sitting or attending meetings. We propose a novel sensor fusion method to detect if a user is near the phone, which achieves more than 90% accuracy. Determining activity and occupancy our proposed algorithms can help maintaining thermal comfort while reducing HVAC energy consumptions. - Highlights: • We propose activity and occupancy detection for efficient HVAC control. • Activity classifier achieves 10% higher accuracy than SVM and kNN. • For occupancy detection we propose a novel sensor fusion method. • Using Weighted Majority Voting we fuse microphone and accelerometer data on phone. • We achieve more than 90% accuracy in detecting occupancy.

  2. Legionella detection and subgrouping in water air-conditioning cooling tower systems in Kuwait.

    Science.gov (United States)

    Al-Matawah, Qadreyah; Al-Zenki, Sameer; Al-Azmi, Ahmad; Al-Waalan, Tahani; Al-Salameen, Fadila; Hejji, Ahmad Ben

    2015-07-01

    The main aim of the study was to test for the presence of Legionnaires' disease-causing microorganisms in air-conditioned buildings in Kuwait using molecular technologies. For this purpose, 547 samples were collected from 38 cooling towers for the analysis of Legionella pneumophila. These samples included those from water (n = 178), air (n = 231), and swabs (n = 138). Out of the 547 samples, 226 (41%) samples were presumptive positive for L. pneumophila, with L. pneumophila viable counts in the positive water samples ranging from 1 to 88 CFU/ml. Of the Legionella culture-positive samples, 204 isolates were examined by latex agglutination. These isolates were predominately identified as L. pneumophila serogroup (sg) 2-14. Using the Dresden panel of monoclonal antibodies, 74 representatives isolates were further serogrouped. Results showed that 51% of the isolates belonged to serogroup 7 followed by 1 (18%) and 3 (18%). Serogroups 4 (4%) and 10 (7%) were isolated at a lower frequency, and two isolates could not be assigned to a serogroup. These results indicate the wide prevalence of L. pneumophila serogroup 7 as the predominant serogroup at the selected sampling sites. Furthermore, the 74 L. pneumophila (sg1 = 13; sg3 = 13; sg4 = 3; sg7 = 38; sg10 = 5; sgX = 2) isolates were genotyped using the seven gene protocol sequence-based typing (SBT) scheme developed by the European Working Group for Legionella Infections (EWGLI). The results show that Legionella isolates were discriminated into nine distinct sequence typing (ST) profiles, five of which were new to the SBT database of EWGLI. Additionally, all of the ST1 serogroup 1 isolates were of the OLDA/Oxford subgroup. These baseline data will form the basis for the development of a Legionella environmental surveillance program and used for future epidemiological investigations.

  3. Exergy and energy analyses of two different types of PCM based thermal management systems for space air conditioning applications

    International Nuclear Information System (INIS)

    Tyagi, V.V.; Pandey, A.K.; Buddhi, D.; Tyagi, S.K.

    2013-01-01

    Highlights: ► Calcium chloride hexahydrate (CaCl 2 ⋅6H 2 O) as a PCM was used in this study. ► Two different capsulated system (HDPE based panel and balls) were designed. ► The results of CaCl 2 ⋅6H 2 O are very attractive for space air conditioning. ► Energy and exergy analyses for space cooling applications. - Abstract: This communication presents the experimental study of PCM based thermal management systems for space heating and cooling applications using energy and exergy analysis. Two different types of based thermal management system (TMS-I and TMS-II) using calcium chloride hexahydrate as the heat carrier has been designed, fabricated and studied for space heating and cooling applications at a typical climatic zone in India. In the first experimental arrangement the charging of PCM has been carried out with air conditioning system while discharging has been carried out using electric heater for both the thermal management systems. While in the second arrangement the charging of PCM has been carried out by solar energy and the discharging has been carried out by circulating the cooler ambient air during the night time. In the first experiment, TMS-I is found to be more effective than that of TMS-II while it was found to be reverse in the case of second experiment for both the charging and discharging processes not only for energetic but also for the exergetic performances

  4. Next Generation Refrigeration Lubricants for Low Global Warming Potential/Low Ozone Depleting Refrigeration and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hessell, Edward

    2013-12-31

    The goal of this project is to develop and test new synthetic lubricants that possess high compatibility with new low ozone depleting (LOD) and low global warming potential (LGWP) refrigerants and offer improved lubricity and wear protection over current lubricant technologies. The improved compatibility of the lubricants with the refrigerants, along with improved lubricating properties, will resulted in lower energy consumption and longer service life of the refrigeration systems used in residential, commercial and industrial heating, ventilating and air-conditioning (HVAC) and refrigeration equipment.

  5. Optimum selection of solar collectors for a solar-driven ejector air conditioning system by experimental and simulation study

    International Nuclear Information System (INIS)

    Zhang Wei; Ma Xiaoli; Omer, S.A.; Riffat, S.B.

    2012-01-01

    Highlights: ► Three solar collectors have been compared to drive ejector air conditioning system. ► A simulation program was constructed to study the effect parameters. ► The outdoor test were conducted to validate the solar collector modeling. ► Simulation program was found to predict solar collector performance accurately. ► The optimal design of solar collector system was carried out. - Abstract: In this paper, three different solar collectors are selected to drive the solar ejector air conditioning system for Mediterranean climate. The performance of the three selected solar collector are evaluated by computer simulation and lab test. Computer model is incorporated with a set of heat balance equations being able to analyze heat transfer process occurring in separate regions of the collector. It is found simulation and test has a good agreement. By the analysis of the computer simulation and test result, the solar ejector cooling system using the evacuated tube collector with selective surface and high performance heat pipe can be most economical when operated at the optimum generating temperature of the ejector cooling machine.

  6. Cold Vacuum Drying facility heating, ventilation, and Air Conditioning system design description

    International Nuclear Information System (INIS)

    SINGH, G.

    2000-01-01

    This System Design Description (SDD) addresses the HVAC system for the CVDF. The CVDF HVAC system consists of five subsystems: (1) Administration building HVAC system; (2) Process bay recirculation HVAC system; (3) Process bay local exhaust HVAC and process vent system; (4) Process general supply/exhaust HVAC system; and (5) Reference air system. The HVAC and reference air systems interface with the following systems: the fire protection control system, Monitoring and Control System (MCS), electrical power distribution system (including standby power), compressed air system, Chilled Water (CHW) system, drainage system, and other Cold Vacuum Drying (CVD) control systems not addressed in this SDD

  7. Capability of air filters to retain airborne bacteria and molds in heating, ventilating and air-conditioning (HVAC) systems.

    Science.gov (United States)

    Möritz, M; Peters, H; Nipko, B; Rüden, H

    2001-07-01

    The capability of air filters (filterclass: F6, F7) to retain airborne outdoor microorganisms was examined in field experiments in two heating, ventilating and air conditioning (HVAC) systems. At the beginning of the 15-month investigation period, the first filter stages of both HVAC systems were equipped with new unused air filters. The number of airborne bacteria and molds before and behind the filters were determined simultaneously in 14 days-intervals using 6-stage Andersen cascade impactors. Under relatively dry ( 12 degrees C) outdoor air conditions air filters led to a marked reduction of airborne microorganism concentrations (bacteria by approximately 70% and molds by > 80%). However, during long periods of high relative humidity (> 80% R. H.) a proliferation of bacteria on air filters with subsequent release into the filtered air occurred. These microorganisms were mainly smaller than 1.1 microns therefore being part of the respirable fraction. The results showed furthermore that one possibility to avoid microbial proliferation is to limit the relative humidity in the area of the air filters to 80% R. H. (mean of 3 days), e.g. by using preheaters in front of air filters in HVAC-systems.

  8. Experimental and Numerical Study of the Radiant Induction-Unit and the Induction Radiant Air-Conditioning System

    Directory of Open Access Journals (Sweden)

    Qiang Si

    2016-12-01

    Full Text Available In this paper we proposed the novel air-conditioning system which combined induction ventilation and radiant air-conditioning. The indoor terminal device is the radiant induction-unit (RIDU. The RIDU is the induction unit combined with the pore radiant panel on which the copper pipes with rigid aluminum diffusion fins are installed. The two-stage evaporator chiller with the non-azeotropic mixture refrigerant is utilized in the system to reduce the initial investment in equipment. With the performance test and the steady state heat transfer model based on the theory of radiative heat transfer, the relationship between the induction ratio of the RIDU and the characteristic of the air supply was studied. Based on this, it is verified that the RIDU has a lower dew-point temperature and better anti-condensation performance than a traditional plate-type radiant panel. The characteristics of the radiation and convection heat transfer of the RIDU were studied. The total heat exchange of the RIDU can be 16.5% greater than that of the traditional plate-type radiant terminal.

  9. Analysis of economic and environmental benefits of a new heat pump air conditioning system with a heat recovery device

    Science.gov (United States)

    Li, lingxue

    2017-08-01

    The paper designs a new wind-water cooling and heating water conditioner system, connects cooling tower with heat recovery device, which uses cooling water to completely remove the heat that does not need heat recollection, in order to ensure that the system can work efficiently with higher performance coefficient. After the test actual engineering operation, the system’s maximum cooling coefficient of performance can reach 3.5. Its maximum comprehensive coefficient of performance can reach 6.5. After the analysis of its economic and environmental, we conclude that the new system can save 89822 kw per year. It reflects energy-saving and environmental benefits of the cold and hot water air conditioning system.

  10. An inverse method for calculation of thermal inertia and heat gain in air conditioning and refrigeration systems

    International Nuclear Information System (INIS)

    Fayazbakhsh, M.A.; Bagheri, F.; Bahrami, M.

    2015-01-01

    Highlights: • An inverse method is proposed to calculate thermal inertia in HVAC-R systems. • Real-time thermal loads are estimated using the proposed intelligent algorithm. • Calculation algorithm is validated with on-site measurements. • Freezer duty cycle data are extracted only based on temperature measurements. - Abstract: A new inverse method is proposed for estimation of thermal inertia and heat gain in air conditioning and refrigeration systems using on-site temperature measurements. The method is applied on a walk-in freezer room of a restaurant in Surrey, British Columbia, Canada during one week of its regular operation. The thermal inertia and instantaneous heat gain are calculated and the results are validated using actual information of the materials inside the freezer room. The proposed method can be implemented in intelligent control systems designed for new and existing HVAC-R systems to improve their overall energy efficiency and reduce their environmental impacts

  11. Research and application of an intelligent control system in central air-conditioning based on energy consumption simulation

    Science.gov (United States)

    Cao, Ling; Che, Wenbin

    2018-05-01

    For the central air-conditioning energy-saving, it is common practice to use a wide range of PTD controllers in engineering to optimize energy savings. However, the shortcomings of the PTD controller have also been magnified on this issue, such as: calculation accuracy is not enough, the calculation time is too long. Particle swarm optimization has the advantage of fast convergence. This paper is based on Particle Swarm Optimization apply in PTD controller tuning parameters in order to achieve the purpose of saving energy while ensuring comfort. The algorithm proposed in this paper can adjust the weight according to the change of population fitness, reduce the weights of particles with lower fitness and enhance the weights of particles with higher fitness in the population, and fully release the population vitality. The method in this paper is validated by the TRNSYS model based on the central air-conditioning system. The experimental results show that the room temperature fluctuation is small, the overshoot is small, the adjustment speed is fast, and the energy-saving fluctuates at 10%.

  12. An Investigation about using Nanorefrigerants in Air Conditioning Systems According to the Theoretical, CFD and Experimental Review of the Recent Literature

    Directory of Open Access Journals (Sweden)

    Farshad Panahizadeh

    2016-10-01

    Full Text Available Greenhouse gases (GHG causing global warming and climate change. In the year 2014, 32.3 billion tones CO2 emitted to the atmosphere as the most important greenhouse gas. According to the statistics, a significant portion of this amount is related to electricity demand of air conditioning systems, for producing a one ton of refrigeration in HVAC air cooled or water cooled systems respectively 1026 and 764 grams GHG emitted in the atmosphere. Therefore, air conditioning systems have an important role in the global warming and climate change. By increasing the COP of air conditioning systems the electricity demand of them reduced. One strategy for increasing the COP of air conditioning systems is using nanorefrigerants. In the present study, a comprehensive information is given regarding to use nanorefrigerants in air conditioning systems according to the theoretical, CFD and experimental review of the recent literature. This paper gives assistance to designers of air conditioning systems in their future efforts for selecting refrigerant for their systems

  13. 2016 German refrigeration and air conditioning meeting. Proceedings

    International Nuclear Information System (INIS)

    2016-01-01

    The following topics were dealt with: Large cryogenic facilities, relief valves, liquid helium, liquid-nitrogen and liquid hydrogen cooling, new concepts, foundations and materials of the heat-pump techniques, evaporation, phase-change materials, absorption, afterheat usage, ionic liquids, sorption, condensers, heat exchangers, back-cooling systems, refrigerants, caron dioxide, mobile applications, efficiency and optimization, air conditioning.

  14. Development and Design of a User Interface for a Computer Automated Heating, Ventilation, and Air Conditioning System

    International Nuclear Information System (INIS)

    Anderson, B.

    1999-01-01

    A user interface is created to monitor and operate the heating, ventilation, and air conditioning system. The interface is networked to the system's programmable logic controller. The controller maintains automated control of the system. The user through the interface is able to see the status of the system and override or adjust the automatic control features. The interface is programmed to show digital readouts of system equipment as well as visual queues of system operational statuses. It also provides information for system design and component interaction. The interface is made easier to read by simple designs, color coordination, and graphics. Fermi National Accelerator Laboratory (Fermi lab) conducts high energy particle physics research. Part of this research involves collision experiments with protons, and anti-protons. These interactions are contained within one of two massive detectors along Fermilab's largest particle accelerator the Tevatron. The D-Zero Assembly Building houses one of these detectors. At this time detector systems are being upgraded for a second experiment run, titled Run II. Unlike the previous run, systems at D-Zero must be computer automated so operators do not have to continually monitor and adjust these systems during the run. Human intervention should only be necessary for system start up and shut down, and equipment failure. Part of this upgrade includes the heating, ventilation, and air conditioning system (HVAC system). The HVAC system is responsible for controlling two subsystems, the air temperatures of the D-Zero Assembly Building and associated collision hall, as well as six separate water systems used in the heating and cooling of the air and detector components. The BYAC system is automated by a programmable logic controller. In order to provide system monitoring and operator control a user interface is required. This paper will address methods and strategies used to design and implement an effective user interface

  15. Performance improvement of VAV air conditioning system through feedforward compensation decoupling and genetic algorithm

    International Nuclear Information System (INIS)

    Wang Jun; Wang Yan

    2008-01-01

    VAV (variable air volume) control system has the feature of multi-control loops. While all the control loops are working together, they interfere and influence each other. This paper designs the decoupling compensation unit in VAV system in the method of feedforward compensation. This paper also designs the controller parameters of VAV system by means of inverse deducing and the genetic algorithm. Experimental results demonstrate that the combination of the feedforward compensation decoupling and the controller optimization by genetic algorithm can improve the performance of the VAV control system

  16. Assessment of the thermal environment effects on human comfort and health for the development of novel air conditioning system in tropical regions

    Energy Technology Data Exchange (ETDEWEB)

    Sookchaiya, Thammanoon; Monyakul, Veerapol; Thepa, Sirichai [Division of Energy Technology, School of Energy Environment and Materials, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand)

    2010-10-15

    This research shows the result of a brainstorming by medical experts in the first ranking university medical school and hospital of Thailand. It was based on Delphi technique. The objective of this research was to study both direct and indirect effects of humidity and temperature on human health in air-conditioned buildings in Thailand. Afterwards, the result was used to design and develop split type air conditioner (conventional air conditioner) which could control relative humidity and temperature with precision air conditioning system to comply with the climate and the suitability of the people living in Thailand building. The result of operation with precision inverter air conditioning system showed that the temperature inside the room changed from the default value around {+-}0.2 C (Case 1) and around {+-}0.35 C (Case 2) and it could control relative humidity as a desired condition between 50-60% (both cases) which was the appropriate range for Thai climate. Moreover, energy consumption of precision inverter air conditioning system was still less than conventional air conditioning system for about 7.5%. This research could provide people living in Thailand air conditioned building with human thermal comfort and health. (author)

  17. Using Acid Number as a Leading Indicator of Refrigeration and Air Conditioning System Performance

    Energy Technology Data Exchange (ETDEWEB)

    Dennis Cartlidge; Hans Schellhase

    2003-07-31

    This report summarizes a literature review to assess the acidity characteristics of the older mineral oil and newer polyolester (POE) refrigeration systems as well as to evaluate acid measuring techniques used in other non-aqueous systems which may be applicable for refrigeration systems. Failure in the older chlorofluorocarbon/hydrochlorofluorocarbon (CFC/HCFC) / mineral oil systems was primarily due to thermal degradation of the refrigerant which resulted in the formation of hydrochloric and hydrofluoric acids. These are strong mineral acids, which can, over time, severely corrode the system metals and lead to the formation of copper plating on iron surfaces. The oil lubricants used in the older systems were relatively stable and were not prone to hydrolytic degradation due to the low solubility of water in oil. The refrigerants in the newer hydrofluorocarbon (HFC)/POE systems are much more thermally stable than the older CFC/HCFC refrigerants and mineral acid formation is negligible. However, acidity is produced in the new systems by hydrolytic decomposition of the POE lubricants with water to produce the parent organic acids and alcohols used to prepare the POE. The individual acids can therefore vary but they are generally C5 to C9 carboxylic acids. Organic acids are much weaker and far less corrosive to metals than the mineral acids from the older systems but they can, over long time periods, react with metals to form carboxylic metal salts. The salts tend to accumulate in narrow areas such as capillary tubes, particularly if residual hydrocarbon processing chemicals are present in the system, which can lead to plugging. The rate of acid production from POEs varies on a number of factors including chemical structure, moisture levels, temperature, acid concentration and metals. The hydrolysis rate of reaction can be reduced by using driers to reduce the free water concentration and by using scavenging chemicals which react with the system acids. Total acid

  18. Analysis and Choice of Optimal Heating Ventilation Air Conditioning System for a Teaching Unit

    Directory of Open Access Journals (Sweden)

    Marina Verdeş

    2007-01-01

    Full Text Available Under the conditions of present society in which providing an optimum interior comfort is confronted with the necessity of the energy consumption reduction, solving this problem depends on the factors which contribute to the achievements of this comfort. Modern buildings -- implicitly teaching unit -- may be equipped with installations which have low energy consumption, respective a heating, cooling and ventilating integrated system with heat pumps system which can assure all the required comfort conditions. This paper underlines the necessity to use the heat pump in heating system for a teaching unit, energetic and economic guides and the possibility to increase them when using cooling and heating mixed. The solution of heat pumps for heating of the teaching unit and the energetic and economic advantages of the system is made in study.

  19. Optimization analysis of high temperature heat pump coupling to desiccant wheel air conditioning system

    DEFF Research Database (Denmark)

    Sheng, Ying; Zhang, Yufeng; Fang, Lei

    2014-01-01

    The high temperature heat pump and desiccant wheel (HTHP&DW) system can make full use of heat released from the condenser of heat pump for DW regeneration without additional heat. In this study, DW operation in the HTHP&DW system was investigated experimentally, and the optimization analysis...... of HTHP&DW system was carried out. The performance of DW had influence on the dehumidification (evaluated by dehumidification and regeneration effectiveness) and cooling load (evaluated by thermal and adiabatic effectiveness). The results show that the enthalpy increase occurred in all the experiments...... of the system. When the regeneration temperature is 63°C, the maximal dehumidification effectiveness is 35.4% and the satisfied adiabatic effectiveness is 88%, which contributes to the optimal balance between dehumidification and cooling. © 2014 Tianjin University and Springer-Verlag Berlin Heidelberg....

  20. Air conditioning systems of Porsche Panamera; Das Klimatisierungssystem des Porsche Panamera

    Energy Technology Data Exchange (ETDEWEB)

    Mall, Gernot; Deyhle, Hagen [Porsche AG, Stuttgart (Germany); Engelhardt, Martin [Behr GmbH und Co. KG, Stuttgart (Germany); Gremme, Johannes [BehrHella Thermocontrol GmbH, Lippstadt (Germany)

    2010-07-01

    The Porsche Panama, an innovative Gran Turismo is the newest edition to the Porsche sportscar family. The Panamera climate control system is a major contributor in achieving the goal of premium driver comfort. In addition to excellent performance and comfort requirements on the system and package and an uncompromising lightweight design, premium comfort for the rear seat passengers was of special emphasis. These targets were achieved through a newly developed 2- respective 4-zone climate control system. The climatic comfort from the passenger's point of view is enhanced due to the ability to individually set temperature, air distribution and air volume for every passenger. The system incorporates a model based ''air volume control'' and uses a distinguishing feature, a dashboard integrated air distribution field. (orig.)

  1. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, E; Wen, SY; Shi, L; da Silva, AK

    2013-12-01

    A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system's dynamic behavior, such as a dynamic air flow rate into the vehicle's cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle's cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid-air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semianalytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid-air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system experimental data for solidification using paraffin wax as the PCM. Through modeling, we demonstrate the importance of capturing the airside heat exchange impact on system performance, and we investigate system response to dynamic operating conditions, e.g., air recirculation. (C) 2013 Elsevier Ltd. All rights reserved.

  2. [Hygienic assessment of a recirculatory combined air-conditioning extract-and-input system in office building].

    Science.gov (United States)

    Malysheva, A G; Abramov, E G

    2006-01-01

    The high concentrations of lead were reveled in the air and dust of some premises and on the filters of a combined air-conditioning extract-and-input system in the high-rise office buildings located in the ecologically lead favorable environment. The dust content of lead in some premises on the first floors dust was as high as 200 mg/kg, which was more than 6 times higher than that in the soil at the highway near the office buildings. The use of new technologies and devices for cleaning and optimizing the air in the premises requires analytical studies to assess the quality of the environment, by taking into account the optimal conditions of their operation.

  3. Energy performance of supermarket refrigeration and air conditioning integrated systems working with natural refrigerants

    International Nuclear Information System (INIS)

    Cecchinato, Luca; Corradi, Marco; Minetto, Silvia

    2012-01-01

    The current trends in commercial refrigeration aim at reducing the synthetic refrigerant charge, either by minimising the internal volume of the circuit or by utilising natural refrigerants, and at energy saving. The energy efficiency of supermarkets can be improved by optimising components design, recovering thermal and refrigerating energy, adopting innovative technology solutions, integrating the HVAC system with medium temperature and low temperature refrigeration plants and, finally, reducing thermal loads on refrigerated cases. This study aims at investigating the performance of different lay-out and technological solutions where only natural refrigerants are used and at finding the potential for improving energy efficiency over the traditional systems in different climates. In the analysis, chillers and heat pumps working with ammonia or propane, medium temperature systems working with ammonia or propane and carbon dioxide as heat transfer fluid or with carbon dioxide as the refrigerant and low temperature systems working with carbon dioxide are considered and benchmarked with a state-of-the-art HFCs based plant. The most efficient investigated solution enables an annual energy saving higher than 15% with respect to the baseline solution for all the considered climates. - Highlights: ► Different natural refrigerants supermarket HVAC and R integrated systems are analysed. ► Some of the proposed solutions offer a significant benefit over the baseline one. ► Up to 18.7% energy saving is achieved in the considered climates. ► The refrigeration unit condensation by the AC chiller offers the poorest results.

  4. Control of multi-evaporator air-conditioning systems for flow distribution

    International Nuclear Information System (INIS)

    Lin, J.-L.; Yeh, T.-J.

    2009-01-01

    Modern air-conditioners incorporate variable-speed compressors and variable-opening expansion valves as the actuators for improving cooling performance and energy efficiency. These actuators have to be properly feedback-controlled; otherwise the systems may exhibit even poorer performance than the conventional machines which use fixed-speed compressors and mechanical expansion valves. In this paper, a control strategy with flow distribution capability is proposed for multi-evaporator air-conditioners to accommodate different thermal demands in different rooms. The structure in the control strategy is based on a low-order, linear model obtained from system identification. To determine appropriate control parameters, theorems regarding stability of the closed-loop system are given. Moreover, by performing steady-state analysis on the control system and utilizing characteristics of the identified system parameters, one can analytically explain the mechanics of flow distribution. Experiments indicate that the proposed strategy can successfully regulate the indoor temperatures regardless that the reference settings for respective rooms are different and the settings are switched in the middle of the control process.

  5. Experimental study of an air conditioning system to control a greenhouse microclimate

    International Nuclear Information System (INIS)

    Attar, I.; Naili, N.; Khalifa, N.; Hazami, M.; Lazaar, M.; Farhat, A.

    2014-01-01

    Highlights: • Contribution in the control of the greenhouse microclimate for pepper cultivation. • The energy storing in the ground and in the water ensure the greenhouse heating. • The circulation of the cold water in the exchangers ensures the greenhouse cooling. • The system makes the greenhouse appropriate for the pepper cultivation whole year. - Abstract: In this papper, a thermal model is developed to investigate the possibility to use the ground thermal energy for the greenhouse heating or cooling. A control system of the ground heat storing is integrated in a chapel greenhouse located in the premises of the Technology and Research Energy Center, Tunis, Tunisia. Polypropylene capillary heat exchangers, suspended in the air and buried into the ground of the greenhouse, are used to store or destore solar energy excess. During the day, the air-suspended exchangers recuperate the solar energy in excess. This recuperated energy is then stored into the ground through the buried exchangers. At night the stored thermal energy is brought back by the suspended exchangers to heat the greenhouse air. The purpose of this study is to contribute in the greenhouse microclimate control. In order to maintain the greenhouse air temperature at 20 °C, suitable for a defined agriculture, the solar energy and the cold water are respectively used for heating and cooling the greenhouse inside air. The design and construction of a chapel greenhouse equipped with the control system is carried out. The studied system is used, at the same time for; heating, cooling the greenhouse air and storing the solar energy in excess. Experiments were conducted during the years 2012–2013, to evaluate the effectiveness of the control system achieved. The measured values of the greenhouse air temperatures with and without the control system are discussed

  6. An analysis of heating, ventilation and air conditioning system for nuclear facilities

    International Nuclear Information System (INIS)

    Park, Hyun Soo; Kim, Byung Tae; Park, Seong Won; Cho, Soo Haeng; Lee, Yong Rae; Lee, Kyung Ku; Park, Seung Hyub; Hwang, Jeong Ki; Kim, Jeong Mook; Oh, Haeng Yoeb

    1988-12-01

    An analysis of HVAC system was made on various nuclear facilities such as the existing nuclear power plants in Korea, Post Irradiation Examination Facility at KAERI and Midwest Fuel Recovery Plant in USA, to get basic data and information for the design of the spent fuel interim storage facility to be implemented as one of the radwaste management projects. With the results of this study, the HVAC system to be applied to the spent fuel interim storage facility was selected and the major design considerations of the facility were suggested. (Author)

  7. Fungal colonization of air filters for use in heating, ventilating, and air conditioning (HVAC) systems.

    Science.gov (United States)

    Simmons, R B; Crow, S A

    1995-01-01

    New and used cellulosic air filters for HVAC systems including those treated with antimicrobials were suspended in vessels with a range of relative humidities (55-99%) and containing non-sterile potting soil which stimulates fungal growth. Most filters yielded fungi prior to suspension in the chambers but only two of 14 nontreated filters demonstrated fungal colonization following use in HVAC systems. Filters treated with antimicrobials, particularly a phosphated amine complex, demonstrated markedly less fungal colonization than nontreated filters. In comparison with nontreated cellulosic filters, fungal colonization of antimicrobial-treated cellulosic filters was selective and delayed.

  8. Analysis of energy management for heating, ventilating and air-conditioning systems

    Directory of Open Access Journals (Sweden)

    Mohamed Elhelw

    2016-06-01

    Full Text Available In the office buildings, large energy is consumed due to poor thermal performance and low efficiencies of HVAC systems. A cooling load calculation is a basis for the design of building cooling systems. The current design methods are usually based on deterministic cooling loads, which are obtained by using design parameters. However, these parameters contain uncertainties, and they will be different from that used in the design calculation when the cooling system is put in use. The actual cooling load profile will deviate from that predicted in design. A modified bin method was used in this paper to optimize the energy efficiency ratio (EER. A design optimization method is proposed by considering uncertainties related to the cooling load calculation. Impacts caused by the uncertainties of seven factors are considered, including the outdoor weather conditions and internal heat sources. The cooling load distribution is analyzed. Comparison between the modified bin method and CLTD/SCL/CLF method is also conducted. With the distributions of their energy consumption, decision makers can select the optimal configuration based on quantified confidence. According to the economic benefits and energy efficiency ratio, using modified bin method will increase the overall energy efficiency ratio by 45.57%.

  9. Analysis of flow maldistribution in fin-and-tube evaporators for residential air-conditioning systems

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl

    superheat by distributing individual channel mass flow rate continuously (perfect control). The compensation method is compared to the use of a larger evaporator in order to study their trade-off in augmenting system performance (cooling capacity and COP). The studies are performed by numerical modeling...... profile across the A-coil evaporator was predicted by means of CFD simulation software STAR-CD 3.26 (2005) and applied in the numerical model. The main reason for the better face split evaporator performance at uniform conditions or when compensating, is that the superheated "weak" zones with low UA...

  10. AUTOMATED SYSTEM OF OPERATIONAL CONTROL HEATING AND AIR CONDITIONING OF BUILDINGS

    Directory of Open Access Journals (Sweden)

    PETRENKO A. O.

    2016-08-01

    Full Text Available Statement of the problem. Health and human performance largely determined by the conditions of climate and air quality in residential, administrative and residential and public buildings. At that, in turn, is influenced by the external environment and the climate, and the geometric dimensions of the room, and thermal performance building envelopes, and the location of the premises (Orientation, and many other factors. The result is the formation of complex systems, which control decision-making in conditions of multifactor [1]. In hygienic purposes it is necessary to strive to create the best indoor microclimate conditions, regardless of changes in the factors that affect the climate in residential, administrative and residential and public buildings. Develop systems to ensure the necessary microclimate parameters – it is a complex and important task, which will depend entirely comfortable and cozy environment for the person. The problem of the present time, there is a steady increase in the energy consumption of these systems, due to the rise in price of non-renewable energy sources, and our job is, to simulate the work of software systems necessary microclimate for the changes in the factors that affect it and to minimize the use of non-renewable energy sources. Analysis of recent research and publications. Domestic and foreign hygienists [2, 3, 4] to establish a connection between the climate in the room and in the workplace and the state of human health. Formation of the indoor climate of residential, administrative and residential and public buildings is influenced by many factors that have already noted earlier [5, 6]. Study of the processes of influence of various factors on human health is of great complexity. If we consider each process separately, and in this case they are not currently amenable to theoretical description clearer. To simulate the effect of these factors studies were conducted, which showed that, with sufficient

  11. Near-optimal order-reduced control for A/C (air-conditioning) system of EVs (electric vehicles)

    International Nuclear Information System (INIS)

    Chiu, Chien-Chin; Tsai, Nan-Chyuan; Lin, Chun-Chi

    2014-01-01

    This work is aimed to investigate the regulation problem for thermal comfortableness and propose control strategies for cabin environment of EVs (electric vehicles) by constructing a reduced-scale A/C (air-conditioning) system which mainly consists of two modules: ECB (environmental control box) and AHU (air-handling unit). Temperature and humidity in the ECB can be regulated by AHU via cooling, heating, mixing air streams and adjusting speed of fans. To synthesize the near-optimal controllers, the mathematical model for the system thermodynamics is developed by employing the equivalent lumped heat capacity approach, energy/mass conservation principle and the heat transfer theories. In addition, from the clustering pattern of system eigenvalues, the thermodynamics of the interested system can evidently be characterized by two-time-scale property. That is, the studied system can be decoupled into two subsystems, slow mode and fast mode, by singular perturbation technique. As to the optimal control strategies for EVs, by taking thermal comfortableness, humidity and energy consumption all into account, a series of optimal controllers is synthesized on the base of the order-reduced thermodynamic model. The feedback control loop for the experimental test rig is examined and realized by the aid of the control system development kit dSPACE DS1104 and the commercial software MATLAB/Simulink. To sum up, the intensive computer simulations and experimental results verify that the performance of the near-optimal order-reduced control law is almost as superior as that of standard LQR (Linear-Quadratic Regulator). - Highlights: • A reduced-scale test rig for A/C (air-conditioning) system to imitate the temperature/humidity of cabin in EV (electric vehicle) is constructed. • The non-linear thermodynamic model of A/C system can be decoupled by singular perturbation technique. • The temperature/humidity in cabin is regulated to the desired values by proposed optimal

  12. Energy and exergy analysis of a geothermal heat pump air conditioning system

    International Nuclear Information System (INIS)

    Baccoli, Roberto; Mastino, Costantino; Rodriguez, Giuseppe

    2015-01-01

    This paper considers the energy analysis of a heat pump system coupled to the ground by means of vertical exchangers, to verify which thermodynamic boundary conditions, in terms of thermal conductivity and diffusivity of the ground and the grout, make it competitive in comparison with other technologies harnessing atmospheric air as the heat source. The comparison is based on the maximum theoretical efficiency available in correspondence to the temperature effectively assumed by the thermal energy reservoirs in contact with the evaporator and the condenser during the operating conditions. The comparison of the two sources/sinks of heat, i.e. the ground and atmospheric air, represents the comparison between the time trend of the exergy of the two reservoirs required by an ideal GSHP and ASHP respectively. A fully transient heat transfer model able to handle on a time scale of a year or more and with a refinement of less than an hour is considered, since short term variations have significant effects on the overall performance of GSHP. In this paper the borehole heat transfer problem in the Laplace domain is solved for any trend and duration of thermal loads, taking into account an existing analytical approximation model of the full solution proposed by Lamarche and Beauchamp. A numerical inversion using the Inverse Discrete Fourier Transform is then applied to obtain the time domain solution. The method combines the flexibility and accuracy of the analytical model with the superior efficiency of the computational time offered by the numerical inversion if compared with that of methods based on the convolution scheme. - Highlights: • The energy and exergy analysis of a GSHP versus a ASHP system is considered. • The model works on a time scale of a year, with a refinement of less than an hour. • Flexibility and efficiency are combined by an analytical model and numerical inversion. • For which order of λ and α the GSHP is not competitive respect to ASHP is

  13. Evaluation of Heating, Ventilation, and Air conditioning (HVAC System Performance in an Administrative Building in Tehran (Iran

    Directory of Open Access Journals (Sweden)

    H. Mari Oriyad

    2014-09-01

    Full Text Available Introduction: One of the factors influencing on indoor air quality of the buildings is performance of HVAC (heating, ventilation, and air conditioning systems. These systems supply clean and odorless air, with temperature, humidity, and air velocity within comfort ranges for the residents. The aim of this study was to evaluate performance HVAC system in an administrative building in Tehran. .Material and Method: A questionnaire, developed in their research was used to assess the building occupants’ perception about the performance of HVAC system. To evaluate the performance of HVAC systems, air velocities were measured in the diffusers using a thermal anemometer. Moreover, CO2 concentration, air temperature and relative humidity were measured in the whole floors of the building. Air distribution inside the building was evaluated using smoke test. .Results: Most of the studied people complained about the direction of airflow, thermal conditions and cigarette odor. The highest level of carbon dioxide was measured at 930 ppm inside the restaurant. The maximum and minimum air temperatures and relative humidity were measured 28.3-13.8° C and 28.4-23% respectively. Smoke test showed that the air distribution/direction wasn’t suitable in one third of air diffusers. .Conclusion: Improper air distribution / direction was the main problem with the studied HVAC system which could be corrected by adjusting and balancing of the system.

  14. Performance Analysis of an Integrated Heat Pump with Air-Conditioning System for the Existing Hospital Building Application

    Directory of Open Access Journals (Sweden)

    Chen-Yu Chiang

    2017-03-01

    Full Text Available In this study, a complete evaluation procedure of energy-saving and efficiency improvement for a large-scale hospital retrofit project has been established and successfully validated in Taiwan. The retrofit scheme, in integrating the alternative hot water system, namely, a water source heat pump (WSHP, with the existing HVAC (Heating, Ventilating, and Air-Conditioning system, enables the capability to meet the cooling and hot water demand simultaneously with a larger safety margin as well as saving energy. In addition, it has been found that the integrated system provides a new source for cooling which can be utilized as a system redundancy in avoiding system shutdown. This is very useful when considering in specific areas in the hospital, such as intensive care unit, or operation rooms, where cooling should not be interrupted on any occasion. In this study, it is validated that the coefficient of performance (COP of the newly added WSHP system, under heating and cooling mode, is 3.62 and 2.62, respectively. The recorded annual cost reduction by this integrated system is $102,564, with a payback of 1.2 years. The hospital after retrofit has been operating safer, with more redundancy, and more energy-efficient which warrants tremendous potential for implementation in the industry.

  15. Evaluation of refrigerating and air-conditioning technologies in heat cascading systems under the carbon dioxide emissions constraint: the proposal of the energy cascade balance table

    International Nuclear Information System (INIS)

    Shimazaki, Yoichi

    2003-01-01

    The aim of this study was to evaluate the refrigerating and air-conditioning technologies in cases of introducing both heat cascading systems and thermal recycling systems in industries located around urban areas. It is necessary to introduce heat cascading systems in the industrial sector in Japan to reduce carbon dioxide emissions. The concept of heat cascading is the multi-stage use of thermal energy by temperature level. This paper introduces three energy policies for introducing the heat cascading systems. The author develops an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Carbon dioxide emission constraints result in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature heat is shifted to refrigeration. It was found that increasing the amount of garbage combustion waste heat could reduce electric power for the turbo compression refrigerator by promoting waste heat driven ammonia absorption refrigerator. In addition, this study proposes an energy cascade balance table with respect to the temperature level

  16. Development of novel control strategy for multiple circuit, roof top bus air conditioning system in hot humid countries

    Energy Technology Data Exchange (ETDEWEB)

    Khamis Mansour, M.; Musa, Md Nor; Wan Hassan, Mat Nawi; Saqr, Khalid M. [Thermo-Fluid Department, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru (Malaysia)

    2008-06-15

    A novel control strategy to improve energy efficiency and to enhance passengers' thermal comfort of a new roof top bus multiple circuit air conditioning (AC) system operating on partial load conditions is presented. A novel strategy for automatic control of the AC system was developed based on numerous experimental test runs at various operating conditions, taking into account energy saving and thermal comfort without sacrificing the proper cycling rate of the system compressor. For this task, more than 50 test runs were conducted at different set point temperatures of 21, 22 and 23 C. Fanger's method was used to evaluate passenger thermal comfort, and the system energy consumption was also calculated. A performance comparison between that of the conventional AC system and that of the newly developed one has been conducted. The comparison revealed that the adopted control strategy introduces significant improvements in terms of thermal comfort and energy saving on various partial load conditions. Potential energy saving of up to 31.6% could be achieved. This results in a short payback period of 17 months. It was found from the economic analysis that the new system is able to save approximately 20.0% of the life cycle cost. (author)

  17. Match properties of heat transfer and coupled heat and mass transfer processes in air-conditioning system

    International Nuclear Information System (INIS)

    Zhang Tao; Liu Xiaohua; Zhang Lun; Jiang Yi

    2012-01-01

    Highlights: ► Investigates match properties of heat or mass transfer processes in HVAC system. ► Losses are caused by limited transfer ability, flow and parameter mismatching. ► Condition of flow matching is the same heat capacity of the fluids. ► Parameter matching is only reached along the saturation line in air–water system. ► Analytical solutions of heat and mass transfer resistance are derived. - Abstract: Sensible heat exchangers and coupled heat and mass transfer devices between humid air and water/desiccant are commonly used devices in air-conditioning systems. This paper focuses on the match properties of sensible heat transfer processes and coupled heat and mass transfer processes in an effort to understand the reasons for performance limitations in order to optimize system performance. Limited heat transfer capability and flow mismatching resulted in heat resistance of the sensible heat transfer process. Losses occurred during the heat and mass transfer processes due to limited transfer capability, flow mismatching, and parameter mismatching. Flow matching was achieved when the heat capacities of the fluids were identical, and parameter matching could only be reached along the saturation line in air–water systems or the iso-concentration line in air–desiccant systems. Analytical solutions of heat transfer resistance and mass transfer resistance were then derived. The heat and mass transfer process close to the saturation line is recommended, and heating sprayed water resulted in better humidification performance than heating inlet air in the air humidifier.

  18. Development of novel control strategy for multiple circuit, roof top bus air conditioning system in hot humid countries

    International Nuclear Information System (INIS)

    Khamis Mansour, M.; Musa, Md Nor; Mat Nawi Wan Hassan; Saqr, Khalid M.

    2008-01-01

    A novel control strategy to improve energy efficiency and to enhance passengers' thermal comfort of a new roof top bus multiple circuit air conditioning (AC) system operating on partial load conditions is presented. A novel strategy for automatic control of the AC system was developed based on numerous experimental test runs at various operating conditions, taking into account energy saving and thermal comfort without sacrificing the proper cycling rate of the system compressor. For this task, more than 50 test runs were conducted at different set point temperatures of 21, 22 and 23 deg. C. Fanger's method was used to evaluate passenger thermal comfort, and the system energy consumption was also calculated. A performance comparison between that of the conventional AC system and that of the newly developed one has been conducted. The comparison revealed that the adopted control strategy introduces significant improvements in terms of thermal comfort and energy saving on various partial load conditions. Potential energy saving of up to 31.6% could be achieved. This results in a short payback period of 17 months. It was found from the economic analysis that the new system is able to save approximately 20.0% of the life cycle cost

  19. Experimental Investigation of an Automobile Air-Conditioning System using Integrated Brushless Direct Current Motor Rotary Compressor

    Directory of Open Access Journals (Sweden)

    Sukri M.F.

    2016-01-01

    Full Text Available The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP. Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X. In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X, the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T5 (35ºC, or at T5 = 30ºC for constant X (4.96.

  20. Air conditioning system

    Science.gov (United States)

    Lowenstein, Andrew; Miller, Jeffrey; Gruendeman, Peter; DaSilva, Michael

    2005-02-01

    An air conditioner comprises a plurality of plates arranged in a successively stacked configuration with portions thereof having a spaced apart arrangement, and defining between successive adjacent pairs of plates at the spaced apart portions a first and second series of discrete alternating passages wherein a first air stream is passed through the first series of passages and a second air stream is passed through the second series of passages; and said stacked configuration of plates forming integrally therewith a liquid delivery means for delivering from a source a sufficient quantity of a liquid to the inside surfaces of the first series of fluid passages in a manner which provides a continuous flow of the liquid from a first end to a second end of the plurality of plates while in contact with the first air stream.

  1. Simulation study on the operating characteristics of the heat pipe for combined evaporative cooling of computer room air-conditioning system

    International Nuclear Information System (INIS)

    Han, Zongwei; Zhang, Yanqing; Meng, Xin; Liu, Qiankun; Li, Weiliang; Han, Yu; Zhang, Yanhong

    2016-01-01

    In order to improve the energy efficiency of air conditioning systems in computer rooms, this paper proposed a new concept of integrating evaporative cooling air-conditioning system with heat pipes. Based on a computer room in Shenyang, China, a mathematical model was built to perform transient simulations of the new system. The annual dynamical performance of the new system was then compared with a typical conventional computer room air-conditioning system. The result showed that the new integrated air-conditioning system had better energy efficiency, i.e. 31.31% reduction in energy consumption and 29.49% increase in COP (coefficient of performance), due to the adoption of evaporative condenser and the separate type heat pipe technology. Further study also revealed that the incorporated heat pipes enabled a 36.88% of decrease in the operation duration of the vapor compressor, and a 53.86% of reduction for the activation times of the compressor, which could lead to a longer lifespan of the compressor. The new integrated evaporative cooling air-conditioning system was also tested in different climate regions. It showed that the energy saving of the new system was greatly affected by climate, and it had the best effect in cold and dry regions like Shenyang with up to 31.31% energy saving. In some warm and humid climate regions like Guangzhou, the energy saving could be achieved up to 13.66%. - Highlights: • A novel combined air-conditioning system of computer room is constructed. • The performance of the system and conventional system is simulated and compared. • The applicability of the system in different climate regions is investigated.

  2. Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV) systems.

    Science.gov (United States)

    Ng, Bing Feng; Xiong, Jin Wen; Wan, Man Pun

    2017-01-01

    The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM) indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop) that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle clusters to enhance PM capturing efficiency without adding flow resistance in the air distribution ductwork could provide an energy-efficient solution. This pre-conditioning mechanism can be fulfilled by acoustic agglomeration, which is a phenomenon that promotes the coagulation of suspended particles by acoustic waves propagating in the fluid medium. This paper discusses the basic mechanisms of acoustic agglomeration along with influencing factors that could affect the agglomeration efficiency. The feasibility to apply acoustic agglomeration to improve filtration in air-conditioning and mechanical ventilation (ACMV) systems is investigated experimentally in a small-scale wind tunnel. Experimental results indicate that this novel application of acoustic pre-conditioning improves the PM2.5 filtration efficiency of the test filters by up to 10% without introducing additional pressure drop. The fan energy savings from not having to switch to a high capturing efficiency filter largely outstrip the additional energy consumed by the acoustics system. This, as a whole, demonstrates potential energy savings from the combined acoustic-enhanced filtration system without compromising on PM capturing efficiency.

  3. Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV systems.

    Directory of Open Access Journals (Sweden)

    Bing Feng Ng

    Full Text Available The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle clusters to enhance PM capturing efficiency without adding flow resistance in the air distribution ductwork could provide an energy-efficient solution. This pre-conditioning mechanism can be fulfilled by acoustic agglomeration, which is a phenomenon that promotes the coagulation of suspended particles by acoustic waves propagating in the fluid medium. This paper discusses the basic mechanisms of acoustic agglomeration along with influencing factors that could affect the agglomeration efficiency. The feasibility to apply acoustic agglomeration to improve filtration in air-conditioning and mechanical ventilation (ACMV systems is investigated experimentally in a small-scale wind tunnel. Experimental results indicate that this novel application of acoustic pre-conditioning improves the PM2.5 filtration efficiency of the test filters by up to 10% without introducing additional pressure drop. The fan energy savings from not having to switch to a high capturing efficiency filter largely outstrip the additional energy consumed by the acoustics system. This, as a whole, demonstrates potential energy savings from the combined acoustic-enhanced filtration system without compromising on PM capturing efficiency.

  4. Thermal characteristics of non-edible oils as phase change materials candidate to application of air conditioning chilled water system

    Science.gov (United States)

    Irsyad, M.; Indartono, Y. S.; Suwono, A.; Pasek, A. D.

    2015-09-01

    The addition of phase change material in the secondary refrigerant has been able to reduce the energy consumption of air conditioning systems in chilled water system. This material has a high thermal density because its energy is stored as latent heat. Based on material melting and freezing point, there are several non-edible oils that can be studied as a phase change material candidate for the application of chilled water systems. Forests and plantations in Indonesia have great potential to produce non-edible oil derived from the seeds of the plant, such as; Calophyllum inophyllum, Jatropha curcas L, and Hevea braziliensis. Based on the melting temperature, these oils can further studied to be used as material mixing in the secondary refrigerant. Thermal characteristics are obtained from the testing of T-history, Differential Scanning Calorimetric (DSC) and thermal conductivity materials. Test results showed an increase in the value of the latent heat when mixed with water with the addition of surfactant. Thermal characteristics of each material of the test results are shown completely in discussion section of this article.

  5. Presentation of an innovative and efficient air conditioning system for electrical powered vehicles; Vorstellung eines innovativen und effizienten Klimasystems fuer elektrisch angetriebene Fahrzeuge

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Oleg [IAV GmbH, Muenchen (Germany); Ackermann, Jan; Fang, Fang [IAV GmbH, Gifhorn (Germany)

    2012-11-01

    An air-conditioning system for battery electric vehicles requires an efficient approach to provide heat and cool during operation in winter and summer. The required energy expenditure to ensure comfort and safety is enormous especially during the winter. The heat input into the cabin amounts up to 10 kW and above when considering conventional vehicles with an internal combustion engine. In this context IAV is developing an efficient overall air conditioning system. The combination of new system components, such as surface heaters and a heat pump with improved components such as a PTC-heater, can solve the discrepancy between acceptable range and the aspects of comfort and safety. (orig.)

  6. Energy and exergy performance analysis of a marine rotary desiccant air-conditioning system based on orthogonal experiment

    International Nuclear Information System (INIS)

    Zhu, Jun; Chen, Wu

    2014-01-01

    A novel marine rotary desiccant A/C (air-conditioning) system was developed and studied to improve energy utilization efficiency of ship A/C. The orthogonal experiment was first carried out to investigate the influence of various parameters of the marine rotary desiccant A/C system. During the orthogonal experiment the analysis of variance was used to exclude interference from the secondary influencing factor on system performance. The significant influencing factors of system were studied in great detail using the first and second laws of thermodynamics to find optimal setting parameters for best system performance. It is suggested from the analysis results that as regeneration temperature increases, the COP th (thermal coefficient of performance) and exergy efficiency of system (η e ) decreases by 46.9% and 38.8% respectively. They decrease in proportion to the increase of the temperature. η e reaches its maximum value of about 23.5% when the inlet humidity ratio of process air is 22 g/kg. Besides, the exergy loss of system concentrates on the regeneration air heater, the desiccant wheel and the regeneration air leaving the desiccant wheel, which account for 68.4%–81% of the total exergy loss. It can be concluded that applying the marine rotary desiccant A/C in high-temperature and high-humidity marine environment is advantageous. - Highlights: • Significant influencing factors of the system are found by the analysis of variance. • The change trends of the COP th and the η e are nearly proportional with the regeneration temperature. • The η e reaches its maximum value (about 23.5%) when the inlet humidity ratio of process air is 22 g/kg. • The contribution rate of the dry-bulb temperature of fresh air is up to 73.91% for the COP th . • Applying the marine rotary desiccant A/C in high-temperature and high-humidity marine environment is advantageous

  7. Investigation on output capacity control strategy of variable refrigerant flow air conditioning system with multi-compressor

    International Nuclear Information System (INIS)

    Tu, Qiu; Zou, Deqiu; Deng, Chenmian; Zhang, Jie; Hou, Lifeng; Yang, Min; Nong, Guicai; Feng, Yuhai

    2016-01-01

    Highlights: • The control model of compressor output capacity has been built. • The control strategy of compressor switching has been presented. • The switching process of standard compressor has been described. • The characteristics of EER and noise have been presented. • The control strategy and model have been proved by experiments. - Abstract: A set of 14 HP variable refrigerant flow air conditioning system (VRF AC) with multi-compressor has been designed, and the output capacity control strategy of compressor(s) including the switching control model of standard compressor has been built. In the output capacity control model, a certain suction pressure is used as the pressure control target to adjust the output capacity of compressors, and a little pressure fluctuation is taken into account to amend the target pressure. Furthermore, in the compressor switching control model, the most favorable operation frequency region is determined on base of the energy efficiency characteristic and noise characteristic of the compressor. And, in order to solve the large fluctuation problem of the system running and frequent ON-OFF action of the standard compressor, the equal output capacity switching principle can be used to determine the thermo-on and thermo-off switched frequency points, and control the switching process of the compressor. Experiments demonstrate the feasibility of this control strategy to ensure the stability and reliability, improve the energy efficiency and reduce the compressor noise.

  8. Effectiveness of photocatalytic filter for removing volatile organic compounds in the heating, ventilation, and air conditioning system.

    Science.gov (United States)

    Yu, Kuo-Pin; Lee, Grace Whei-May; Huang, Wei-Ming; Wu, Chih-Cheng; Lou, Chia-ling; Yang, Shinhao

    2006-05-01

    Nowadays, the heating, ventilation, and air conditioning (HVAC) system has been an important facility for maintaining indoor air quality. However, the primary function of typical HVAC systems is to control the temperature and humidity of the supply air. Most indoor air pollutants, such as volatile organic compounds (VOCs), cannot be removed by typical HVAC systems. Thus, some air handling units for removing VOCs should be added in typical HVAC systems. Among all of the air cleaning techniques used to remove indoor VOCs, photocatalytic oxidation is an attractive alternative technique for indoor air purification and deodorization. The objective of this research is to investigate the VOC removal efficiency of the photocatalytic filter in a HVAC system. Toluene and formaldehyde were chosen as the target pollutants. The experiments were conducted in a stainless steel chamber equipped with a simplified HVAC system. A mechanical filter coated with Degussa P25 titania photocatalyst and two commercial photocatalytic filters were used as the photocatalytic filters in this simplified HVAC system. The total air change rates were controlled at 0.5, 0.75, 1, 1.25, and 1.5 hr(-1), and the relative humidity (RH) was controlled at 30%, 50%, and 70%. The ultraviolet lamp used was a 4-W, ultraviolet-C (central wavelength at 254 nm) strip light bulb. The first-order decay constant of toluene and formaldehyde found in this study ranged from 0.381 to 1.01 hr(-1) under different total air change rates, from 0.34 to 0.433 hr(-1) under different RH, and from 0.381 to 0.433 hr(-1) for different photocatalytic filters.

  9. Development of air conditioning system and labor saving technology for efficient hydroponic cultivation; Konoritsuna suiko saibai no tame no kucho to shoryokuka gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okano, T.; Terazoe, H.; Shoji, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Yonezawa, K.; Otani, F. [Chugoku Electric Power Co. Inc., Hiroshima (Japan); Sekiyama, T.; Kosakai, K.; Sato, H.

    1997-06-01

    Equipment which made experiments on air conditioning and hydroponic cultivation possible was set up at the technical research center of the Chugoku Electric Power Co., to study an air conditioning system using night power and energy saving technology for the cultivation. Vegetables suitable to the cultivation were selected. For air conditioning, adopted was a water heat storage air conditioning system using night power. The space between the shade curtain and the greenhouse roof was ventilated to prevent increase in cooling load caused by rise in curtain temperature. Moreover, the cultivation equipment was covered with transparent vinyl film to cool the inside of the equipment. The hydroponic cultivation equipment was trially manufactured which makes the continued production by one worker possible. The cultivation of spinach, leaf lettuce and chingensai throughout the year became possible. The yield of chingensai reached the target, but those of spinach and leaf lettuce were approximately 70% of the targets. Vegetables to be produced in the air-conditioned greenhouse by hydroponic cultivation are thought to be those that can have added values such non-pesticides and ingredients, young plants which were increased by cutting or tissue culturing, etc. 5 refs., 19 figs., 8 tabs.

  10. Study on Heat Utilization in an Attached Sunspace in a House with a Central Heating, Ventilation, and Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Qingsong Ma

    2018-05-01

    Full Text Available Based on numerical simulations, the heating load reduction effect of an attached sunspace in winter was determined, and the effective heat utilization method and sunspace design were explored. In this paper, we studied the heating load reduction effect using heat from the sunspace and temperature fluctuation of each room at the time of heat use from the sunspace (sending air from the sunspace to the heating, ventilation, and air conditioning (HVAC machine room and taking the air to the adjacent rooms. In the case of the all-day HVAC system, it was confirmed that a larger capacity of sunspace and not sending air from the sunspace to the adjacent room demonstrated a better heating-load reduction effect. Compared with Model Iw (a house with a window on the exterior of the sunspace opened to external air, Model I (a house with an attached sunspace on the second floor could save approximately 41% of the total energy. Model II (a house with the attached sunspace both on the first and second floors could save approximately 84% of the total energy. Sending heat from the sunspace to the adjacent room led to temperature increases in the adjacent rooms. However, if the construction plan is to have the sunspace only on the second floor, the house should be carefully designed, for example, by placing a living room on the second floor.

  11. Performance improvement of a hybrid air conditioning system using the indirect evaporative cooler with internal baffles as a pre-cooling unit

    Directory of Open Access Journals (Sweden)

    A.E. Kabeel

    2017-12-01

    Full Text Available In the present paper, the effects of the indirect evaporative cooler with internal baffle on the performance of the hybrid air conditioning system are numerically investigated. The hybrid air conditioning system contains two indirect evaporative coolers with internal baffle, one is utilized to pre-cool the air inlet to the desiccant wheel and the other is utilized to pre-cool the supply air inlet to the room. The effects of the inlet conditions of the process and reactivation air and working air ratio on the thermal performance of the hybrid air conditioning system have been analyzed. The results of this study show that in the hybrid air conditioning system for using the indirect evaporative cooler with internal baffle as a pre-cooling unit, the supply air temperature reduced by 21% and the coefficient of performance improved by 71% as compared to previous designs of the hybrid air conditioning system at the same inlet conditions. For increasing process air inlet temperature from 25 °C to 45 °C, supply air temperature increases from 12.7 °C to 14.2 °C, thermal COP increases from 1.87 to 2.84, and supply air relative humidity increases from 76.7% to 77.4%. Also, for increasing the reactivation air inlet temperature from 70 °C to 110 °C, supply air temperature dropped from 15.9 °C to 10.9 °C, supply air relative humidity dropped from 82.7% to 71.8%, and thermal COP dropped from 4.5 to 1.7. The recommended optimal air working ratio in the indirect evaporative cooler with internal baffle should be 0.15. Keywords: Desiccant material, Solar air collector, Evaporative cooler, Internal baffles, Air conditioning

  12. Visualization of the influence of the air conditioning system to the high-power laser beam quality with the modulation coherent imaging method.

    Science.gov (United States)

    Tao, Hua; Veetil, Suhas P; Pan, Xingchen; Liu, Cheng; Zhu, Jianqiang

    2015-08-01

    Air conditioning systems can lead to dynamic phase change in the laser beams of high-power laser facilities for the inertial confinement fusion, and this kind of phase change cannot be measured by most of the commonly employed Hartmann wavefront sensor or interferometry due to some uncontrollable factors, such as too large laser beam diameters and the limited space of the facility. It is demonstrated that this problem can be solved using a scheme based on modulation coherent imaging, and thus the influence of the air conditioning system on the performance of the high-power facility can be evaluated directly.

  13. An energy-saving set-point optimizer with a sliding mode controller for automotive air-conditioning/refrigeration systems

    International Nuclear Information System (INIS)

    Huang, Yanjun; Khajepour, Amir; Ding, Haitao; Bagheri, Farshid; Bahrami, Majid

    2017-01-01

    Highlights: • A novel two-layer energy-saving controller for automotive A/C-R system is developed. • A set-point optimizer at the outer loop is designed based on the steady state model. • A sliding mode controller in the inner loop is built. • Extensively experiments studies show that about 9% energy can be saving by this controller. - Abstract: This paper presents an energy-saving controller for automotive air-conditioning/refrigeration (A/C-R) systems. With their extensive application in homes, industry, and vehicles, A/C-R systems are consuming considerable amounts of energy. The proposed controller consists of two different time-scale layers. The outer or the slow time-scale layer called a set-point optimizer is used to find the set points related to energy efficiency by using the steady state model; whereas, the inner or the fast time-scale layer is used to track the obtained set points. In the inner loop, thanks to its robustness, a sliding mode controller (SMC) is utilized to track the set point of the cargo temperature. The currently used on/off controller is presented and employed as a basis for comparison to the proposed controller. More importantly, the real experimental results under several disturbed scenarios are analysed to demonstrate how the proposed controller can improve performance while reducing the energy consumption by 9% comparing with the on/off controller. The controller is suitable for any type of A/C-R system even though it is applied to an automotive A/C-R system in this paper.

  14. Experimental Assessment of residential split type air-conditioning systems using alternative refrigerants to R-22 at high ambient temperatures

    International Nuclear Information System (INIS)

    Joudi, Khalid A.; Al-Amir, Qusay R.

    2014-01-01

    Highlights: • R290, R407C and R410A in residential split A/C units at high ambient. • 1 and 2 TR residential air conditioners with R22 alternatives at high ambient. • Residential split unit performance at ambients up to 55 °C with R22 alternatives. - Abstract: Steady state performance of residential air conditioning systems using R22 and alternatives R290, R407C, R410A, at high ambient temperatures, have been investigated experimentally. System performance parameters such as optimum refrigerant charge, coefficient of performance, cooling capacity, power consumption, pressure ratio, power per ton of refrigeration and TEWI environmental factor have been determined. All refrigerants were tested in the cooling mode operation under high ambient air temperatures, up to 55 °C, to determine their suitability. Two split type air conditioner of 1 and 2 TR capacities were used. A psychrometric test facility was constructed consisting of a conditioned cool compartment and an environmental duct serving the condenser. Air inside the conditioned compartment was maintained at 25 °C dry bulb and 19 °C wet bulb for all tests. In the environmental duct, the ambient air temperature was varied from 35 °C to 55 °C in 5 °C increments. The study showed that R290 is the better candidate to replace R22 under high ambient air temperatures. It has lower TEWI values and a better coefficient of performance than the other refrigerants tested. It is suitable as a drop-in refrigerant. R407C has the closest performance to R22, followed by R410A

  15. Energy performance of solar-assisted liquid desiccant air-conditioning system for commercial building in main climate zones

    International Nuclear Information System (INIS)

    Qi, Ronghui; Lu, Lin; Huang, Yu

    2014-01-01

    Highlights: • Simulation of solar liquid desiccant AC system in four climate regions was conducted. • System performance was determined by relationship of sensible and latent cooling load. • For humid area, saving amount is large by handling latent load with solar energy. • For dry area, electricity saving rate is considerable due to the high COP of chillers. • For buildings with mild SHR, the system performance was not as good as others. - Abstract: Liquid desiccant air-conditioning (LDAC) system, which consists of a liquid desiccant ventilation system for dehumidification and an air-handling unit for cooling, has become a promising alternative for conventional technology. To evaluate its feasibility and applicability, the simulation of solar-assisted LDAC (SLDAC) in commercial buildings in five cities of four main climate regions were conducted, including Singapore in Tropical, Houston and Beijing in Temperate, Boulder in Arid and Los Angeles in Mediterranean. Results showed that the system’s performance was seriously affected by the ratios of building’s sensible and latent cooling load. For buildings located in humid areas with low sensible-total heat ratio (SHR), the electricity energy reduction of SLDAC was high, about 450 MW h in Houston and Singapore, which accounted for 40% of the total energy consumption in cooling seasons. The cost payback period was as short as approximately 7 years. The main reason is that the energy required for handling the moisture could be saved by liquid desiccant dehumidification, and the regeneration heat could be covered by solar collectors. For buildings in dry climate with high SHR, the total cooling load was low, but up to 45% electricity of AC system could be saved in Boulder because the chiller COP could be significantly improved during more than 70% operation time. The cost payback period was around 22 years, which was acceptable. However, for the buildings with mild SHR, such as those in Beijing and Los

  16. IMPACT OF HEATING AND AIR CONDITIONING SYSTEM OPERATION AND LEAKAGE ON VENTILATION AND INTERCOMPARTMENT TRANSPORT: STUDIES IN UNOCCUPIED AND OCCUPIED TENNESSEE VALLEY HOMES

    Science.gov (United States)

    Forced-air heating and air conditioning (HAC) systems caused an average and maximum increase in air infiltration rates of 1.8- and 4.3-fold, respectively, during brief whole-house studies of tracer gas decay In 39 occupied houses. An average Increase in air infiltration rate of 0...

  17. The Maintenance of Heating, Ventilating and Air-Conditioning Systems and Indoor Air Quality in Schools: A Guide for School Facility Managers. Technical Bulletin.

    Science.gov (United States)

    Wheeler, Arthur E.

    To help maintain good indoor air quality (IAQ) in schools, guidance for the development and implementation of an effective program for maintenance and operation of heating, ventilating, and air-conditioning (HVAC) systems are discussed. Frequently, a building's occupants will complain about IAQ when the temperature or humidity are at uncomfortable…

  18. Flavisolibacter metallilatus sp. nov., isolated from an automotive air conditioning system and emended description of the genus Flavisolibacter.

    Science.gov (United States)

    Kim, Dong-Uk; Lee, Hyosun; Lee, Suyeon; Kim, Song-Gun; Park, A-Young; Ahn, Jae-Hyung; Ka, Jong-Ok

    2018-03-01

    A Gram-stain-negative, aerobic, non-motile, rod-shaped and pale yellow-pigmented bacterium, designated strain TX0661 T , was isolated from an automotive air conditioning system collected in the Republic of Korea. 16S rRNA gene sequence analysis showed that the strain TX0661 T was grouped with members of the genus Flavisolibacter and the strain had 98.2-95.3 % 16S rRNA gene sequence similarities to the species of the genus Flavisolibacter. DNA-DNA relatedness between TX0661 T and Flavisolibacter ginsenosidimutans KCTC 22818 T and Flavisolibacter ginsengisoli KCTC 12657 T was less than 30 %. The low levels of DNA-DNA relatedness identified strain TX0661 T as a novel species in the genus Flavisolibacter. The strain grew at 28-37 °C (optimum, 37 °C), at pH 6.0-7.0 (optimum, pH 6.5) and in the presence of 0-0.5 % (w/v, optimum, 0.5 %) NaCl. It contained summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and iso-C17 : 0 3-OH as major fatty acids and MK-7 as the predominant menaquinone. The polar lipid profile revealed that the presence of phosphatidylethanolamine, aminoglycophospholipid, two unidentified aminolipids and two unidentified lipids. The DNA G+C content of the strain was 49.1 mol%. Based on phenotypic, genotypic and chemotaxonomic data, strain TX0661 T represents a novel species in the genus Flavisolibacter, for which the name Flavisolibactermetallilatus sp. nov. (=KACC 19145 T =KCTC 52779 T =NBRC 111784 T ) is proposed.

  19. Deinococcus metallilatus sp. nov. and Deinococcus carri sp. nov., isolated from a car air-conditioning system.

    Science.gov (United States)

    Kim, Dong-Uk; Lee, Hyosun; Lee, Ji-Hyeong; Ahn, Jae-Hyung; Lim, Sangyong; Jeong, Sunwook; Park, So Yoon; Seong, Chi Nam; Ka, Jong-Ok

    2015-09-01

    Two bacterial strains, designated MA1002(T) and MA1003(T), were isolated from the air-conditioning system of a car. Cells of both strains were Gram-reaction-positive, non-motile, non-spore-forming coccoids, catalase- and oxidase-positive and UV-radiation resistant. The major fatty acids of strain MA1002(T) were iso-C17 : 0 and iso-C15 : 0 and those of strain MA1003(T) were iso-C16 : 0 and iso-C16 : 1 H. The polar lipid profile of MA1002(T) contained phosphatidylethanolamine, two unidentified phosphoglycolipids, an unidentified phospholipid, an unidentified aminophospholipid, an unidentified aminolipid and an unidentified lipid. MA1003(T) had three unidentified phosphoglycolipids, six unidentified phospholipids, two unidentified glycolipids and two unidentified polar lipids as the polar lipids. The G+C contents of the genomic DNA of MA1002(T) and MA1003(T) were 70.5 and 76.0 mol%, respectively. MK-8 was the predominant respiratory quinone for both strains. 16S rRNA gene sequence analysis showed that strain MA1002(T) was phylogenetically related to Deinococcus apachensis DSM 19763(T), D. geothermalis DSM 11300(T), D. aerius TR0125(T) and D. aetherius ST0316(T) (92.9, 92.6, 92.0 and 91.9% sequence similarity, respectively), and MA1003(T) showed the highest sequence similarity to Deinococcus hopiensis KR-140(T) (92.9%) and D. xinjiangensis X-82(T) (91.4%). The results of genotypic and phenotypic characterizations showed that both strains could be distinguished from phylogenetically related species, and that the strains represented novel species within the genus Deinococcus, for which we propose the names Deinococcus metallilatus sp. nov. (type strain MA1002(T) = KACC 17964(T) = NBRC 110141(T)) and Deinococcus carri sp. nov. (type strain is MA1003(T) = KACC 17965(T) = NBRC 110142(T)).

  20. Heating, ventilating, and air-conditioning applications

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This book covers: Comfort air conditioning and heating of residences: Space HVAC systems; Industrial and special air conditioning and ventilation for nuclear facilities, and for mines; Energy sources, such as Geothermal energy, solar utilization, and energy resources; Building operation and maintenance; energy management, and Thermal storage

  1. Impact of the Air-Conditioning System on the Power Consumption of an Electric Vehicle Powered by Lithium-Ion Battery

    Directory of Open Access Journals (Sweden)

    Brahim Mebarki

    2013-01-01

    Full Text Available The car occupies the daily universe of our society; however, noise pollution, global warming gas emissions, and increased fuel consumption are constantly increasing. The electric vehicle is one of the recommended solutions by the raison of its zero emission. Heating and air-conditioning (HVAC system is a part of the power system of the vehicle when the purpose is to provide complete thermal comfort for its occupants, however it requires far more energy than any other car accessory. Electric vehicles have a low-energy storage capacity, and HVAC may consume a substantial amount of the total energy stored, considerably reducing the vehicle range, which is one of the most important parameters for EV acceptability. The basic goal of this paper is to simulate the air-conditioning system impact on the power energy source of an electric vehicle powered by a lithium-ion battery.

  2. Energy Savings Potential and Research, Development, & Demonstration Opportunities for Residential Building Heating, Ventilation, and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Inc., Burlington, MA (United States); Zogg, Robert [Navigant Consulting, Inc., Burlington, MA (United States); Young, Jim [Navigant Consulting, Inc., Burlington, MA (United States); Schmidt, Justin [Navigant Consulting, Inc., Burlington, MA (United States)

    2012-10-01

    This report is an assessment of 135 different heating, ventilation, and air-conditioning (HVAC) technologies for U.S. residential buildings to identify and provide analysis on 19 priority technology options in various stages of development. The analyses include an estimation of technical energy-savings potential, descriptions of technical maturity, descriptions of non-energy benefits, descriptions of current barriers for market adoption, and descriptions of the technology's applicability to different building or HVAC equipment types. From these technology descriptions, are suggestions for potential research, development and demonstration (RD&D) initiatives that would support further development of the priority technology options.

  3. Energy Savings Potential and Research, Development, & Demonstration Opportunities for Commercial Building Heating, Ventilation, and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-09-01

    This report covers an assessment of 182 different heating, ventilation, and air-conditioning (HVAC) technologies for U.S. commercial buildings to identify and provide analysis on 17 priority technology options in various stages of development. The analyses include an estimation of technical energy-savings potential, description of technical maturity, description of non-energy benefits, description of current barriers for market adoption, and description of the technology’s applicability to different building or HVAC equipment types. From these technology descriptions, are suggestions for potential research, development and demonstration (RD&D) initiatives that would support further development of the priority technology options.

  4. Optical absorption measurement system

    International Nuclear Information System (INIS)

    Draggoo, V.G.; Morton, R.G.; Sawicki, R.H.; Bissinger, H.D.

    1989-01-01

    This patent describes a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature

  5. Effects of lighting and air-conditioning systems on growth weight and functional composition of frill-lettuce produced in plant factory

    Science.gov (United States)

    Yoshida, Atsumasa; Okamura, Nobuya; Furukawa, Hajime; Myojin, Chiho; Moriuchi, Koji; Kinoshita, Shinichi

    2017-06-01

    The aim of the present study was to develop optimal air-conditioning systems for plant factories. To verify the effect of particular air-conditioning and lighting systems, cultivation experiments were performed with frill-lettuce for two weeks. In the present study, the relationship between the cultivation condition, the yield (i.e., increase in edible portion weight), and the functional components were discussed. Based on the measured data, increased photosynthetic photon flux density increased antioxidative activity and edible portion weight, possibly because high light intensities are stressful for frill lettuce. Antioxidative activity also increased under conditions of low CO2 concentration, weak and strong winds, and high air temperature because these conditions became stresses for the plants. However, a decrease in edible portion weight was observed under these conditions, implying there is a negative correlation between antioxidative activity and edible portion weight.

  6. Performance analysis of proposed hybrid air conditioning and humidification–dehumidification systems for energy saving and water production in hot and dry climatic regions

    International Nuclear Information System (INIS)

    Nada, S.A.; Elattar, H.F.; Fouda, A.

    2015-01-01

    Highlights: • Integrative air-conditioning (A/C) and humidification–dehumidification desalination systems are proposed. • Effects of operating parameters on the proposed systems are investigated. • System configurations that have the highest fresh water production rate, power saving and total cost saving are identified. - Abstract: Performance of integrative air-conditioning (A/C) and humidification–dehumidification desalination systems proposed for hot and dry climatic regions is theoretically investigated. The proposed systems aim to energy saving and systems utilization in fresh water production. Four systems with evaporative cooler and heat recovery units located at different locations are proposed, analyzed and evaluated at different operating parameters (fresh air ratio, supply air temperature and outside air wet bulb temperature). Other two basic systems are used as reference systems in proposed systems assessment. Fresh water production rate, A/C cooling capacity, A/C electrical power consumption, saving in power consumptions and total cost saving (TCS) parameters are used for systems evaluations and comparisons. The results show that (i) the fresh water production rates of the proposed systems increase with increasing fresh air ratio, supply air temperature and outdoor wet bulb temperature, (ii) powers saving of the proposed systems increase with increasing fresh air ratio and supply air temperature and decreasing of the outdoor air wet bulb temperature, (iii) locating the evaporative cooling after the fresh air mixing remarkably increases water production rate, and (vi) incorporating heat recovery in the air conditioning systems with evaporative cooling may adversely affect both of the water production rate and the total cost saving of the system. Comparison study has been presented to identify systems configurations that have the highest fresh water production rate, highest power saving and highest total cost saving. Numerical correlations for

  7. Air conditioning using an air-cooled single effect lithium bromide absorption chiller: Results of a trial conducted in Madrid in August 2005

    International Nuclear Information System (INIS)

    Izquierdo, M.; Lizarte, R.; Marcos, J.D.; Gutierrez, G.

    2008-01-01

    Trials were conducted to determine the performance of a commercial (Rotartica 045v) 4.5-kW air-cooled, single effect LiBr/H 2 O absorption chiller for residential use. The experiments were run at La Poveda, Arganda del Rey, Madrid, in August 2005. Three typical August days, with different outdoor temperatures, were chosen for the study. The hot water inlet temperature in the generator varied throughout the day from 80 to 107 o C. Thermal demand was calculated, along with period energy balance and COP. Variations in machine component temperatures were recorded and chilling power and the daily COP calculated for each of the three days. The results for the period as a whole showed that cooling power tended to decline with rising outdoor dry bulb temperatures. At temperatures from 35 to 41.3 o C the chilled water outlet temperature in the evaporator climbed to over 15 o C. The average COP for the period, when auxiliary equipment was included into the calculations, was 0.37

  8. Study on hybrid ground-coupled heat pump system for air-conditioning in hot-weather areas like Hong Kong

    International Nuclear Information System (INIS)

    Man, Yi; Yang, Hongxing; Wang, Jinggang

    2010-01-01

    The ground-coupled heat pump (GCHP) system is becoming attractive for air-conditioning in some moderate-weather regions due to its high energy efficiency and reliable operation capability. However, when the technology is used in buildings where there is only cooling load in hot-weather areas like Hong Kong, the heat rejected into the ground by the GCHP systems will accumulate around the ground heat exchangers (GHE). This heat accumulation will result in degradation of system performance and increment of system operating costs. This problem can be resolved by using the hybrid ground-coupled heat pump (HGCHP) system, which uses supplemental heat rejecters to reject the accumulated heat. This paper presents a practical hourly simulation model of the HGCHP system by modeling the heat transfer process of the system's main components. The computer program based on this hourly simulation model can be used to calculate the hour-by-hour operation data of the HGCHP system. As a case study, both a HGCHP system and a traditional GCHP system are designed for a hypothetic private residential building located in Hong Kong, and the economic comparisons are conducted between these two types of systems. The simulation results show that the HGCHP system can effectively solve the heat accumulation problem and reduce both the initial costs and operating costs of the air-conditioning system in the building.

  9. Study on hybrid ground-coupled heat pump system for air-conditioning in hot-weather areas like Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Man, Yi; Yang, Hongxing [Renewable Energy Research Group, Department of Building Services Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong (China); Wang, Jinggang [Hebei University of Engineering, Handan (China)

    2010-09-15

    The ground-coupled heat pump (GCHP) system is becoming attractive for air-conditioning in some moderate-weather regions due to its high energy efficiency and reliable operation capability. However, when the technology is used in buildings where there is only cooling load in hot-weather areas like Hong Kong, the heat rejected into the ground by the GCHP systems will accumulate around the ground heat exchangers (GHE). This heat accumulation will result in degradation of system performance and increment of system operating costs. This problem can be resolved by using the hybrid ground-coupled heat pump (HGCHP) system, which uses supplemental heat rejecters to reject the accumulated heat. This paper presents a practical hourly simulation model of the HGCHP system by modeling the heat transfer process of the system's main components. The computer program based on this hourly simulation model can be used to calculate the hour-by-hour operation data of the HGCHP system. As a case study, both a HGCHP system and a traditional GCHP system are designed for a hypothetic private residential building located in Hong Kong, and the economic comparisons are conducted between these two types of systems. The simulation results show that the HGCHP system can effectively solve the heat accumulation problem and reduce both the initial costs and operating costs of the air-conditioning system in the building. (author)

  10. Study on hybrid ground-coupled heat pump system for air-conditioning in hot-weather areas like Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Man, Y.; Yang, H.X. [Hong Kong Polytechnic Univ., Renewable Energy Research Group, Hung Hom, Kowloon, (Hong Kong). Dept. of Building Services Engineering

    2008-07-01

    Due to its high energy efficiency and reliable operation capability, the ground-coupled heat pump (GCHP) system is becoming attractive for air-conditioning in some moderate-weather regions. However, when the technology is used in buildings where there is only cooling load in hot-weather areas such as Hong Kong, the heat rejected into the ground by the GCHP systems will accumulate around the ground heat exchangers (GHE), resulting in degradation of system performance and increased system operating costs. This problem can be resolved by using a hybrid ground-coupled heat pump (HGCHP) system, as it uses supplemental heat rejecters to reject the accumulated heat. By modeling the heat transfer process of the system's main components, this paper presented a practical hourly simulation model of the HGCHP system. Based on this hourly simulation model, the computer program could be used to calculate the hour-by-hour operation data of the HGCHP system according to the cooling and hot water heating loads of a building. The paper discussed a case study that involved a design of both a HGCHP system and a traditional GCHP system for a hypothetical private residential building located in Hong Kong. The economic comparisons were performed between these two types of systems. It was concluded through the simulations that the HGCHP system could effectively solve the heat accumulation problem and reduce both the initial cost and operating cost of the air-conditioning system in the building. 19 refs., 1 tab., 13 figs.

  11. General collaboration offer of Johnson Controls regarding the performance of air conditioning automatic control systems and other buildings` automatic control systems

    Energy Technology Data Exchange (ETDEWEB)

    Gniazdowski, J.

    1995-12-31

    JOHNSON CONTROLS manufactures measuring and control equipment (800 types) and is as well a {open_quotes}turn-key{close_quotes} supplier of complete automatic controls systems for heating, air conditioning, ventilation and refrigerating engineering branches. The Company also supplies Buildings` Computer-Based Supervision and Monitoring Systems that may be applied in both small and large structures. Since 1990 the company has been performing full-range trade and contracting activities on the Polish market. We have our own well-trained technical staff and we collaborate with a series of designing and contracting enterprises that enable us to have our projects carried out all over Poland. The prices of our supplies and services correspond with the level of the Polish market.

  12. Analysis of Direct Outdoor Air Cooling Efficency for Combined Variable Air Volume Air-conditioning System in Stores in Cold Climates of China

    OpenAIRE

    Luo, Zhiwen

    2006-01-01

    Direct outdoor air cooling contributes a lot not only to the improvement of the indoor air quality but also to the energy saving. Its full use will reduce the water chiller’s running time especially in some stores where cooling load keeps much higher and longer than that in other buildings. A novel air-conditioning system named Combined Variable Air Volume system (CVAV), combining a normal AHU with a separate outdoor air supply system, was proposed firstly by the authors. The most attractive ...

  13. Test reference years - meteorological bases for the technical simulation of heating systems and air-conditioning systems

    International Nuclear Information System (INIS)

    Perl, J.

    1991-01-01

    For the FRG (western part) for 12 regions with different climate test reference years (TRY) have been established. The TRYs are used for the simulation of the thermal behaviour of buildings, of the operation of heating and space avc systems, lighting control, solar plants as well as of comparable technical systems. A TRY is a collection of hourly data of important meterological parameters over a whole year. The TRYs include 14 meteorological parameters for temperature, humidity, wind, short- and long-wave radiation, atmospheric pressure, precipitation and description of the weather at that time. A TRY is to correspond to the characteristic weather conditions of the TRY region. (orig.) [de

  14. Effect of inter-cooling on the performance and economics of a solar energy assisted hybrid air conditioning system with six stages one-rotor desiccant wheel

    International Nuclear Information System (INIS)

    Elzahzby, Ali M.; Kabeel, A.E.; Bassuoni, M.M.; Abdelgaied, Mohamed

    2014-01-01

    Highlights: • Development of a mathematical model for predicting the performance of solar energy assisted hybrid air conditioning system. • The model uses a one-rotor six-stage rotary silica gel desiccant wheel. • Theoretical model results are in good agreement with experimental data. • The influences of main operating parameters on optimal rotational speed are discussed. • A life cycle cost analysis of the proposed system has been investigated. - Abstract: In this study, a mathematical model for predicting the performance of solar energy assisted hybrid air conditioning system (SEAHACS) was considered. The desiccant wheels used honeycombed silica gel–haloids composite material. This one-rotor desiccant wheel is divided into six stages, in which two-stage dehumidification process, two-stage pre-cooling process and two-stage regeneration process are realized. Three air streams are involved in the present system. The mathematical model has been validated with the experimental data. As the key operating and design parameter, the range of process air inlet temperature from 27.5 to 45 °C, range of humidity ratio of the inlet process air from 9 to 21 g/kg, process air inlet velocity from 1.5 to 5.5 m/s have been examined for a range of rotation speed from 6 to 20 rev/h. the optimization of this parameters is conducted based on the moisture removal capacity D, relative moisture removal capacity, dehumidification coefficient of performance, thermal coefficient of performance, and supply air temperature and humidity ratio. At last, the influences of these main parameters on optimal rotational speed are discussed. Eventually, the life cycle cost analysis of the solar energy assisted hybrid air conditioning system has been investigated

  15. Hygiene guideline for the planning, installation, and operation of ventilation and air-conditioning systems in health-care settings – Guideline of the German Society for Hospital Hygiene (DGKH

    Directory of Open Access Journals (Sweden)

    Külpmann, Rüdiger

    2016-02-01

    Full Text Available Since the publication of the first “Hospital Hygiene Guideline for the implementation and operation of air conditioning systems (HVAC systems in hospitals” ( in 2002, it was necessary due to the increase in knowledge, new regulations, improved air-conditioning systems and advanced test methods to revise the guideline. Based on the description of the basic features of ventilation concepts, its hygienic test and the usage-based requirements for ventilation, the DGKH section “Ventilation and air conditioning technology” attempts to provide answers for the major air quality issues in the planning, design and the hygienically safe operation of HVAC systems in rooms of health care.

  16. Controlled environment laboratory for the energy certification of refrigeration and air conditioning systems; Laboratorio de ambiente controlado para la certificacion energetica de sistemas de refrigeracion y aire acondicionado

    Energy Technology Data Exchange (ETDEWEB)

    Ambriz, Juan Jose; Romero Paredes, Hernando; Dorantes, Ruben [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico)

    1999-07-01

    In this paper the general characteristics of the Controlled Environment Laboratory (CELAB) are described and some of the possible tests that could be performed in this device to evaluate the energy efficiency in air conditioning systems, domestic refrigeration and industrial refrigeration, as well as tests to evaluate the hydrothermal comfort in national populations, are presented. [Spanish] En este trabajo se describen las caracteristicas generales del Laboratorio de Ambiente Controlado (LAB), y se presentan algunas de las posibles pruebas que podran ser desarrolladas en este dispositivo para evaluar la eficiencia energetica en sistemas de aire acondicionado, refrigeracion domestica y refrigeracion industrial, asi como para pruebas para evaluar el confort hidrotermico en poblaciones nacionales.

  17. FY 1977 Annual report on Sunshine Project results. Research and development of solar energy systems for air conditioning and hot water supply (Research and development of systems for new residential buildings); 1977 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Shinchiku kojin jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-03-31

    This project is aimed at development of devices for solar energy systems for air conditioning and hot water supply, in order to commercialize innovative systems for economic air conditioning and hot water supply for new residential buildings. The research items are (1) development of materials for the devices (e.g., heat collectors and absorption refrigerators), (2) operation of the systems in the test building, and measurement (methods for measurement and evaluation of the systems in the test building, instrumentation systems and operation thereof, and analysis of the measured data), and (3) system analysis (system simulation, comparison of the simulated results with the observed results, and system variations). The item (1) studies economic efficiency, durability and stability of the vacuum glass tube type collectors. The item (2) studies a dripping type generator, refrigerant recycling type generator and generator with a built-in auxiliary heat source for the absorption refrigerators. These types have their own advantages and disadvantages, and it is necessary to establish how these results are to be included in the products. The item (3) changes the collector arrangement, based on the observed data, and improves heat-collecting pump starting/stopping conditions, refrigerator operating conditions and insulation around the primary heat-storage tank. It is necessary to analyze the improved systems. (NEDO)

  18. 2016 German refrigeration and air conditioning meeting. Proceedings; Deutsche Kaelte- und Klimatagung 2016. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-07-01

    The following topics were dealt with: Large cryogenic facilities, relief valves, liquid helium, liquid-nitrogen and liquid hydrogen cooling, new concepts, foundations and materials of the heat-pump techniques, evaporation, phase-change materials, absorption, afterheat usage, ionic liquids, sorption, condensers, heat exchangers, back-cooling systems, refrigerants, caron dioxide, mobile applications, efficiency and optimization, air conditioning.

  19. Absorption-heat-pump system

    Science.gov (United States)

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  20. Proposal for the award of a contract for the design, supply, installation and commissioning of a Heating, Ventilation and Air-Conditioning (HVAC) system for the computer room of the CERN Control Centre

    CERN Document Server

    2012-01-01

    Proposal for the award of a contract for the design, supply, installation and commissioning of a Heating, Ventilation and Air-Conditioning (HVAC) system for the computer room of the CERN Control Centre

  1. Energy Analysis of Selected Air Distribution System of Heating, Ventilation and Air Conditioning System: A Case Study of a Pharmaceutical Company

    Directory of Open Access Journals (Sweden)

    DILEEP KUMAR

    2017-07-01

    Full Text Available The higher energy consumption causes environmental degradation along with depletion of conventional energy resources. The share of energy consumption in buildings is increasing with urbanization and that ultimately requires effective measures for energy conservation. In buildings, HVAC (Heating Ventilation and Air Conditioning systems require huge amount of energy. This paper estimates the effects of compression of duct insulation of an HVAC system onthe auxiliary power consumption and temperature of supplied air. A mathematical model is developed in EES (Engineering Equation Solver to ascertain these effects. The simulation results show that the cooling loss due to the insulation compression is about 14%. By increasing the insulation thickness from 10-40mm at selected points, the heat gain is estimated to decrease from 4.29-2.46kW. In addition to that effects of compression of thermal insulation on GHG (Greenhouse Gas emission are investigated to reduce from 4.2-2.3kg/ kW. Subsequently, the AC (Auxiliary Consumption and temperature of the supplied air decrease by 5% and 0.4oC, respectively

  2. Analysis of energy efficiency retrofit schemes for heating, ventilating and air-conditioning systems in existing office buildings based on the modified bin method

    International Nuclear Information System (INIS)

    Wang, Zhaoxia; Ding, Yan; Geng, Geng; Zhu, Neng

    2014-01-01

    Highlights: • A modified bin method is adopted to propose and optimize the EER schemes. • A case study is presented to demonstrate the analysis procedures of EER schemes. • Pertinent EER schemes for HVAC systems are proposed for the object building. - Abstract: Poor thermal performance of building envelop and low efficiencies of heating, ventilating and air-conditioning (HVAC) systems can always be found in the existing office buildings with large energy consumption. This paper adopted a modified bin method to propose and optimize the energy efficiency retrofit (EER) schemes. An existing office building in Tianjin was selected as an example to demonstrate the procedures of formulating the design scheme. Pertinent retrofit schemes for HVAC system were proposed after the retrofit of building envelop. With comprehensive consideration of energy efficiency and economic benefits, the recommended scheme that could improve the overall energy efficiency by 71.20% was determined

  3. Análisis energético de un sistema híbrido de producción de frío; Energy analysis of a hybrid air conditioning system

    Directory of Open Access Journals (Sweden)

    Yamile Díaz Torres

    2015-04-01

    Full Text Available El artículo presenta los resultados del análisis energético de un sistema híbrido de climatización en los hoteles cubanos. Se efectuó el cálculo de una instalación de climatización por absorción asistido con energía solar, interconectada en serie con un sistema de compresión de vapor existente. El procedimiento de cálculo se desarrolló bajo los principios termodinámicos que rigen esta tecnología y con la ayuda de herramientas matemáticas. Se emplearon metodologías de cálculo como el método de las curvas f-chart para la contribución solar. Se utilizó información estadística de datos meteorológicos y energéticos de un caso de estudio en el Hotel Gran Caribe Jagua de la provincia de Cienfuegos, Cuba. Los resultados demuestran que la utilización de estos sistemas, complementando el sistema centralizado de climatización por agua helada (chiller, constituye una alternativa para reducir el consumo de energía eléctrica y el posible impacto ambiental directo e indirecto. The article presents the results of the energy analysis of a hybrid air conditioning system in Cuban hotels. Calculating an air conditioning system for solar assisted interconnected in series with a compression system under existing steam thermodynamic principles’ governing this technology and the help of mathematical tools absorption was made. Calculation methodologies as the method of curves f -chart for solar contribution were employed, using statistical weather data and energy data of the case study Gran Caribe Jagua of Cienfuegos, Cuba. The results demonstrate that the use of these systems, complementing the central chilled water for air conditioning (chiller system is an alternative to reduce energy consumption and the potential direct and indirect environmental impact.

  4. Air conditioning with small power gas appliances

    International Nuclear Information System (INIS)

    Canci, Franco

    1997-01-01

    This article describes research and test activities on small power air conditioning appliances for residential use carried out in the United States, Japan and Europe. The absorption technology aims at the following objectives: to develop appliances requiring reduced maintenance and having a size comparable with electric units of the same output; to reduce production costs and therefore the final prince by adopting special manufacturing technologies such as welded plate exchangers; to obtain appliances which operate both in summer and winter ( as heat pumps), allowing to minimize management and installation costs in southern European climates. The final aim is to offer the customer one appliance only for the following purposes: hot water production for sanitary use, water refrigeration for summer air conditioning, hot water production production for winter heating. This kind of appliance should have management and maintenance costs similar to current individual boilers

  5. Performance Assessment of a Hybrid Solar-Geothermal Air Conditioning System for Residential Application: Energy, Exergy, and Sustainability Analysis

    OpenAIRE

    Abbasi, Yasser; Baniasadi, Ehsan; Ahmadikia, Hossein

    2016-01-01

    This paper investigates the performance of a ground source heat pump that is coupled with a photovoltaic system to provide cooling and heating demands of a zero-energy residential building. Exergy and sustainability analyses have been conducted to evaluate the exergy destruction rate and SI of different compartments of the hybrid system. The effects of monthly thermal load variations on the performance of the hybrid system are investigated. The hybrid system consists of a vertical ground sour...

  6. Performance Assessment of a Hybrid Solar-Geothermal Air Conditioning System for Residential Application: Energy, Exergy, and Sustainability Analysis

    Directory of Open Access Journals (Sweden)

    Yasser Abbasi

    2016-01-01

    Full Text Available This paper investigates the performance of a ground source heat pump that is coupled with a photovoltaic system to provide cooling and heating demands of a zero-energy residential building. Exergy and sustainability analyses have been conducted to evaluate the exergy destruction rate and SI of different compartments of the hybrid system. The effects of monthly thermal load variations on the performance of the hybrid system are investigated. The hybrid system consists of a vertical ground source heat exchanger, rooftop photovoltaic panels, and a heat pump cycle. Exergetic efficiency of the solar-geothermal heat pump system does not exceed 10 percent, and most exergy destruction takes place in photovoltaic panel, condenser, and evaporator. Although SI of PV system remains constant during a year, SI of GSHP varies depending on cooling and heating mode. The results also show that utilization of this hybrid system can reduce CO2 emissions by almost 70 tons per year.

  7. ASME N511-19XX, Standard for periodic in-service testing of nuclear air treatment, heating, ventilating and air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-08-01

    A draft version of the Standard is presented in this document. The Standard covers the requirements for periodic in-service testing of nuclear safety-related air treatment, heating, ventilating, and air conditioning systems in nuclear facilities. The Standard provides a basis for the development of test programs and does not include acceptance criteria, except in cases where the results of one test influence the performance of other tests. The Standard covers general inspection and test requirements, reference values, inspection and test requirements, generic tests, acceptance criteria, in-service test requirements, testing following an abnormal incident, corrective action requirements, and quality assurance. Mandatory appendices provide a visual inspection checklist and four test procedures. Non-mandatory appendices provide additional information and guidance on mounting frame pressure leak test procedure, corrective action, challenge gas substitute selection criteria, and test program development. 8 refs., 10 tabs.

  8. ASME N511-19XX, Standard for periodic in-service testing of nuclear air treatment, heating, ventilating and air conditioning systems

    International Nuclear Information System (INIS)

    1997-01-01

    A draft version of the Standard is presented in this document. The Standard covers the requirements for periodic in-service testing of nuclear safety-related air treatment, heating, ventilating, and air conditioning systems in nuclear facilities. The Standard provides a basis for the development of test programs and does not include acceptance criteria, except in cases where the results of one test influence the performance of other tests. The Standard covers general inspection and test requirements, reference values, inspection and test requirements, generic tests, acceptance criteria, in-service test requirements, testing following an abnormal incident, corrective action requirements, and quality assurance. Mandatory appendices provide a visual inspection checklist and four test procedures. Non-mandatory appendices provide additional information and guidance on mounting frame pressure leak test procedure, corrective action, challenge gas substitute selection criteria, and test program development. 8 refs., 10 tabs

  9. AN IMPACT OF THE EFFICIENT FUNCTIONING OF THE VENTILATION AND AIR-CONDITIONING SYSTEM ON THERMAL COMFORT OF THE MEDICAL STAFF IN THE OPERATING ROOM

    Directory of Open Access Journals (Sweden)

    Tomasz Jankowski

    2016-11-01

    Full Text Available Ventilation and air conditioning systems are necessary for developing proper parameters of indoor envi-ronment in operating rooms. The main task of ventilation and air conditioning in those specific areas consists in creating desirable temperature, reducing the number of microorganisms and the concen-trations of hazardous gases and substances in the air, as well as ensuring the proper direction of airflow. In Poland, indoor environment in operating rooms has to comply with the requirements set out in three regulations (Journal of Laws of 2002 No. 75, item 690, as amended, Journal of Laws of 2002 No. 217, item 1833, Journal of Laws of 2011 No. 31, item 158, as amended and the document entitled "Guidelines for the design of general hospitals". Given insufficient accuracy of the abovementioned national documents, it is a common practice to use foreign standards, i.e. ASHRAE Standard 170-2013, DIN 1946-4: 2008 and FprCEN TR 16244: 2011. When considering the conditions for thermal comfort, it is important to bear in mind a close link between air flow velocity and air temperature. Air in the zone occupied by patients and medical staff must not cause the sensation of draft. Furthermore, air velocity should be sufficient to eliminate interference caused by the presence of people and other sources of heat. It should also reduce the turbulence level in the air in the operating room. Efficient functioning of ventilation and air conditioning was tested during treatments and operations carried out on three wards of a Warsaw hospital. Tests were performed with the participation of medical staff from various surgical units. They were asked to perform minor manual tasks to simulate work on the op-erating table, and to complete a questionnaire on subjective thermal sensation. The applied methodology is widely used during testing of general and local ventilation in public buildings. Air temperature, relative humidity, air flow supply and exhaust air from the

  10. Value impact analysis of Generic Issue 143, Availability of Heating, Ventilation, Air Conditioning (HVAC) and Chilled Water Systems

    Energy Technology Data Exchange (ETDEWEB)

    Daling, P.M.; Marler, J.E.; Vo, T.V.; Phan, H.; Friley, J.R. [Pacific Northwest Lab., Richland, WA (United States)

    1993-11-01

    This study evaluates the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, ``Availability of HVAC and Chilled Water Systems.`` The study identifies vulnerabilities related to failures of HVAC, chilled water, and room cooling systems; develops estimates of room heatup rates and safety-related equipment vulnerabilities following losses of HVAC/room cooler systems; develops estimates of the core damage frequencies and public risks associated with failures of these systems; develops three proposed resolution strategies to this generic issue; and performs a value/impact analysis of the proposed resolutions. Existing probabilistic risk assessments for four representative plants, including one plant from each vendor, form the basis for the core damage frequency and public risk calculations. Both internal and external events were considered. It was concluded that all three proposed resolution strategies exceed the $1,000/person-rem cost-effectiveness ratio. Additional evaluations were performed to develop ``generic`` insights on potential design-related and configuration-related vulnerabilities and potential high-frequency ({approximately}1E-04/RY) accident sequences that involve failures of HVAC/room cooling functions. It was concluded that, although high-frequency accident sequences may exist at some plants, these high-frequency sequences are plant-specific in nature or have been resolved through hardware and/or operational changes. The plant-specific Individual Plant Examinations are an effective vehicle for identification and resolution of these plant-specific anomalies and hardware configurations.

  11. Value impact analysis of Generic Issue 143, Availability of Heating, Ventilation, Air Conditioning (HVAC) and Chilled Water Systems

    International Nuclear Information System (INIS)

    Daling, P.M.; Marler, J.E.; Vo, T.V.; Phan, H.; Friley, J.R.

    1993-11-01

    This study evaluates the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, ''Availability of HVAC and Chilled Water Systems.'' The study identifies vulnerabilities related to failures of HVAC, chilled water, and room cooling systems; develops estimates of room heatup rates and safety-related equipment vulnerabilities following losses of HVAC/room cooler systems; develops estimates of the core damage frequencies and public risks associated with failures of these systems; develops three proposed resolution strategies to this generic issue; and performs a value/impact analysis of the proposed resolutions. Existing probabilistic risk assessments for four representative plants, including one plant from each vendor, form the basis for the core damage frequency and public risk calculations. Both internal and external events were considered. It was concluded that all three proposed resolution strategies exceed the $1,000/person-rem cost-effectiveness ratio. Additional evaluations were performed to develop ''generic'' insights on potential design-related and configuration-related vulnerabilities and potential high-frequency (∼1E-04/RY) accident sequences that involve failures of HVAC/room cooling functions. It was concluded that, although high-frequency accident sequences may exist at some plants, these high-frequency sequences are plant-specific in nature or have been resolved through hardware and/or operational changes. The plant-specific Individual Plant Examinations are an effective vehicle for identification and resolution of these plant-specific anomalies and hardware configurations

  12. Cycle performance of alternative refrigerants for domestic air-conditioning system based on a small finned tube heat exchanger

    International Nuclear Information System (INIS)

    Cheng, Song; Wang, Shuangfeng; Liu, Zhongmin

    2014-01-01

    In order to find alternative refrigerants which exhibit both favorable cycle performance and environmental friendliness, R32 and R290 were utilized to contrast to R22 and R410A as substitutes in the present study. The experiments were conducted with a 5 mm finned tube heat exchanger based on the enthalpy method in a small split household air conditioner. The results showed that in nominal cooling conditions, the COP R of R32 and R290 were 26.8% and 20.4% higher than R22, 7.3% and 2.1% higher than R410A. And in nominal heating conditions, the COP HR of R32 and R290 were both 11.0% higher than R22, 5.3% higher than R410A. The systems with R290 and R32 have similar capacities to that with R22 and R410A in heating mode, but a relatively huge difference of capacities in cooling mode. In consideration of charge amount, R290 could be considered as the most superior alternative refrigerant in air conditioners with the small finned tube heat exchanger. - Highlights: •Comparisons are made in the air conditioner system based on 5 mm tube fin heat exchanger. •The R22 system has a similar performance to others in heating mode while a huge difference in cooling mode. •The optimal charge of R290 is reduced with nearly no decline in the capacity and COP. •SLHX is attached to the system of R290 and successfully promote safety and capacity. •Heat loads are taken into account to evaluate the advantages and disadvantages of R290 and R32

  13. Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV) systems

    OpenAIRE

    Ng, Bing Feng; Xiong, Jin Wen; Wan, Man Pun

    2017-01-01

    The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM) indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop) that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle cl...

  14. Combined cadmium and elevated ozone affect concentrations of cadmium and antioxidant systems in wheat under fully open-air conditions

    International Nuclear Information System (INIS)

    Guo, Hongyan; Tian, Ran; Zhu, Jianguo; Zhou, Hui; Pei, Daping; Wang, Xiaorong

    2012-01-01

    Highlights: ► Combined effect of elevated O 3 and Cd levels on wheat was studied using the free-air concentration enrichment system. ► Elevated O 3 levels result in an increased concentration of Cd in wheat plants grown on Cd-contaminated soils. ► Combined cadmium and elevated O 3 have a significantly synergic effect on oxidative stress in wheat shoots. - Abstract: Pollution of the environment with both ozone (O 3 ) and heavy metals has been steadily increasing. An understanding of their combined effects on plants, especially crops, is limited. Here we studied the effects of elevated O 3 on oxidative stress and bioaccumulation of cadmium (Cd) in wheat under Cd stress using a free-air concentration enrichment (FACE) system. In this field experiment in Jiangdu (Jiangsu Province, China), wheat plants were grown in pots containing soil with various concentrations of cadmium (0, 2, and 10 mg kg −1 Cd was added to the soil) under ambient conditions and under elevated O 3 levels (50% higher than the ambient O 3 ). Present results showed that elevated O 3 led to higher concentrations of Cd in wheat tissues (shoots, husk and grains) with respect to contaminated soil. Combined exposure to Cd and elevated O 3 levels strongly affected the antioxidant isoenzymes POD, APX and CAT and accelerated oxidative stress in wheat leaves. Our results suggest that elevated O 3 levels cause a reduction in food quality and safety.

  15. Flow in air conditioned rooms

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    1974-01-01

    Flow in air conditioned r ooms is examined by means of model experiments . The different gearnetries giving unsteady, steady three- dimensional and steady twodimensional flow are determined . Velacity profiles and temperature profiles are measured in some of the geometries. A numerical solution...... of the flow equations is demonstrated and the flow in air conditioned rooms in case of steady two dimensional flow is predi cted. Compari son with measured results is shown i n the case of small Archimedes numbers, and predictions are shown at high Archimedes numbers. A numerical prediction of f low and heat...

  16. Infrasonic waves and air-conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Hoenmann, W.

    1986-08-01

    This article is a critical investigation of the recently-suggested possibility that the infrasound generated by an air conditioning system (up to 2o kHz) may adversely affect the well-being of human beings. After an introductory explanation of the infrasonic wave band and the dependency of the sound pressure level on the frequency for decibel values of 20 to 100 (diagram), the relevant results of studies by various experts are quoted. It became apparent that the influence of the inaudible infrasound has been greatly overestimated, whereas audibility was underestimated. Inaudible infrasound was shown to be completely harmless. A number of frequency variation analysis diagrams of various residences (old building, new building) with audibility thresholds marked in. The measurement results discussed in more detail indicate that it is possible not to raise the basic noise level of an air conditioning system in the low-frequency range. Therein lies the actual acoustic chance for air conditioning: In an air-conditioned building, there is no need to ventilate by means of open windows, thereby letting in traffic noise, the nuisance value of which is beyond dispute. (HWJ).

  17. An evaluation of the quantitative effects on radon gas from the modification of a home heating and air conditioning system

    International Nuclear Information System (INIS)

    Montague, A.

    1991-01-01

    The quantitative effects associated with the design, construction, operation, environmental and meteorological conditions on radon gas levels in a typical residential dwelling with a basement, having a measured radon level of approximately 20 pico-curies/liter (pCi/L), are evaluated. After several mechanical and electrical modifications are made on the dwelling's heating system, two different furnace breathing modes are studied. The effect on radon levels in the dwelling are observed as the furnace receives all of its combustion, draft and ventilation air - as the experiment alternates, on a bi-weekly basis - from inside and then outside the dwelling. Radon, barometric pressure, outside temperature, relative humidity, wind-speed and direction are monitored continuously; special household activity in the dwelling is also observed. A novel differential air pressure technique is used to measure inside versus outside house air pressure variations, twice each day, resulting from meteorological conditions, dwelling activity, and the furnace breathing mode. A rigorous statistical analysis is employed that includes sequential linear regression of time-series data, trend corrections to remove variations that contribute to the variance in the data without addition useful information. A novel approach using an electrical analog, to screen out unwanted variations is applied, by utilizing a computer routine to simulate the effect of an electronic RC filter, to achieve the desired analytical discrimination

  18. Mountain Plains Learning Experience Guide: Heating, Refrigeration, & Air Conditioning.

    Science.gov (United States)

    Carey, John

    This Heating, Refrigeration, and Air Conditioning course is comprised of eleven individualized units: (1) Refrigeration Tools, Materials, and Refrigerant; (2) Basic Heating and Air Conditioning; (3) Sealed System Repairs; (4) Basic Refrigeration Systems; (5) Compression Systems and Compressors; (6) Refrigeration Controls; (7) Electric Circuit…

  19. RESULTS OF A PILOT FIELD STUDY TO EVALUATE THE EFFECTIVENESS OF CLEANING RESIDENTIAL HEATING AND AIR-CONDITIONING SYSTEMS AND THE IMPACT ON INDOOR AIR QUALITY AND SYSTEM PERFORMANCE

    Science.gov (United States)

    The report discusses and gives results of a pilot field study to evaluate the effectiveness of air duct cleaning (ADC) as a source removal technique in residential heating and air-conditioning (HAC) systems and its impact on airborne particle, fiber, and bioaerosol concentrations...

  20. Study of practical application of ice-aided air-conditioning to mushroom culture; Shiitake saibaiyo kori chikunetsu reidanbo system no jitsuyoka kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Niiyama, K. [Kansai Electric Power Co. Inc., Osaka (Japan)

    1999-09-10

    This is an ice-aided heat pump system powered by electricity, intended for 'shiitake' mushroom culture. The experimentally built heat pump is used in a 200 square-yard-large shiitake culturing facility in the Kinki district, Japan, and an environmental temperature control test is conducted for a culturing house accommodating 6000 mushroom beds. The cold heat storing capacity in summer is found to be 202Mcal (ice percentage: 66%), and the heat storing capacity in winter 69Mcal (water temperature: 60 degrees). The system is capable of performing air-conditioning while storing heat, and all phases of operation are switched over from one two another automatically, with the exception of the switching between the cooling season and the warming season. In a culturing test conducted in the mushroom beds, with the system kept in operation for approximately 3 months, 5 packs (500g) of mushrooms are collected per bed. This means that the 1-day-1-cycle variable temperature control system achieves an increase of 20 percent over the conventional constant temperature control system which yields only 4 packs. In another test in which 4 kinds of seeds are sown, it is found that variable temperature control is superior to constant temperature control in terms of harvest in the summertime cooling operation. (NEDO)

  1. Report of study 7.3: cooling and air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Russo, F.

    2000-07-01

    the liberalization of the electric industry will have a major impact on the use of gas for cooling due to a potential reduction in electricity prices. This threat might induce gas distribution companies to revise their own marketing initiatives and review their tariffs as well. Two important papers on air conditioning are annexed to the study group report. The first paper is entitled 'Power, heat and chilling with natural gas, fuel cells and air conditioning'. It is focused on a demonstration project, in a hospital, based on the supply of power, heat and cooling through the combined use of fuel cells, absorption cooling machines and solar collectors. The second paper is entitled 'Optimisation of a district heating and cooling system with a double approach at the cooling production and new operating schemes'. It describes a project for a centralized plant for heating, cooling and electricity production. The cooling systems are based on waste heat recovery and the use of absorption technology. (authors)

  2. Stage 1 performance qualification of heat-ventilation air-conditioning (HVAC) system for the manufacturing of Tc-99m Generator at Nuclear Malaysia

    International Nuclear Information System (INIS)

    Yen Ng; Noriah Jamal; Rehir Dahalan; Wan Anuar Wan Awang; Noraisyah Yusof; Shaharum Ramli; Jusnan Hashim; Ariff Hamzah; Wan Firdaus Wan Ishak; Yahaya Talib; Othman Mahmud; Asmah Mohibat; Shafii Khamis; Zulkifli Mohamed Hashim; Zakaria Ibrahim; Shaaban Kasim

    2007-01-01

    Manufacturing of Tc-99m generator is carried out in clean room Block 21 of Malaysian Nuclear Agency, which need to comply current Good Manufacturing Practice requirement. High-ventilation air conditioning (HVAC) is a new renovated system. It is a critical system for maintaining suitable temperature, relative humidity and pressure differential in the clean room. The objective of this paper is to present results on Stage 1 Performance Qualification (PQ) for HVAC. This PQ stage 1 was done from 7 February 2007 till 16 March 2007. Temperature, Relative Humidity and Pressure Differential for each compartment in the clean room was monitored twice daily. The Measurement of air-born particle count was done weekly. Settle plate for microbial test was also done weekly. The results were then analyzed and compared with the pre-determined specification. We found that temperature was within the specs, namely 24 +20 degree C. Relative humidity was less than 65%. Pressure differential shows variation, some compartments are below the specs namely 1-3 mm H 2 O. Air-born particle and microbial test also meet the requirement. The results show that all parameters meeting the specs excepts for the pressure differential for certain compartments are a bit low, but is sufficient to create proper air flow and not cause any risk of cross contamination. The existing HVAC system in the clean room is in compliance to the pre-determined specification. However, further improvement can be made by increasing the pressure differential between compartments. (Author)

  3. Hygiene guideline for the planning, installation, and operation of ventilation and air-conditioning systems in health-care settings - Guideline of the German Society for Hospital Hygiene (DGKH).

    Science.gov (United States)

    Külpmann, Rüdiger; Christiansen, Bärbel; Kramer, Axel; Lüderitz, Peter; Pitten, Frank-Albert; Wille, Frank; Zastrow, Klaus-Dieter; Lemm, Friederike; Sommer, Regina; Halabi, Milo

    2016-01-01

    Since the publication of the first "Hospital Hygiene Guideline for the implementation and operation of air conditioning systems (HVAC systems) in hospitals" (http://www.krankenhaushygiene.de/informationen/fachinformationen/leitlinien/12) in 2002, it was necessary due to the increase in knowledge, new regulations, improved air-conditioning systems and advanced test methods to revise the guideline. Based on the description of the basic features of ventilation concepts, its hygienic test and the usage-based requirements for ventilation, the DGKH section "Ventilation and air conditioning technology" attempts to provide answers for the major air quality issues in the planning, design and the hygienically safe operation of HVAC systems in rooms of health care.

  4. Application of FMEA-DEA (Failure Modes and Effect Analysis - Data Envelopment Analysis) to the air conditioning system of the control room a nuclear power plant

    International Nuclear Information System (INIS)

    Barbosa Junior, Gilberto Varanda

    2007-03-01

    This dissertation presents the FMEA-DEA analysis application to the air conditioning system of the control room of a nuclear power plant. After obtaining the failure modes, the index associated to the occurrence probability, the severity of the effects and the potential of detention, a priority order is established for the failure modes or deviations. This number is obtained by multiplying the three mentioned index that vary in a natural scale from 1 to 10, where the higher the index, the more critical the situation will be. In this work, it is intended to use a model based on the data envelopment analysis, DEA jointly with the FMEA, to identify the current efficiency of the system and which failure modes or deviations are considered more critical, and by means of the weights attributed for the mathematical modeling to identify which index are contributing more for these deviations. From this identification, improvements can be set, which may consider administrative changes, operator training and so on, thus adding value to the final product. (author)

  5. Health effects of air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Molina, C.; Caillaud, D.

    The air conditioning used in residential or commercial buildings (offices, hotels, sterile areas of hospitals, computer and electronics industries) is responsible for a certain number of well identified ailments which can be classified in three groups: infections (legionnaires'disease, ornithosis), allergies (mainly respiratory) eg. rhinitis, asthma, alveolitis but also Monday morning illness or humidifier fever, various functional disorders grouped under the name Sick Building Syndrome. To avoid these problems, a certain number of recommendations may be made. They concern: installation of air conditioning, humidification which is the cause of bacterial and fungal contamination, filtration, monitoring of the installation by qualitative and quantitative measurements, maintenance. The legal problems relating to these illnesses, the responsibility for which is ultimately laid at the door of the installers, should also be mentioned. Allergies are recognized to be of professional origin in Table 66 of allergic illnesses issued by the Social Security.

  6. Carbon dioxide R744 as a refrigerant in automotive air-conditioning systems; Kohlendioxid-R744 als Kaeltemittel in Fahrzeug-Klimaanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, P.; Graz, M.; Obrist, F. [Obrist Engineering GmbH (Germany); Parsch, W. [LuK Fahrzeug-Hydraulik GmbH und Co. KG (Germany); Rinne, F. [Sanden Technical Center (Europe) GmbH (Germany)

    2001-12-01

    Toyota's announcement that they are to use environmentally friendly, high-performance air-conditioning systems based on the refrigerant R744 as from the year 2003 confirms a world-wide trend. German competitors documented their development achievements in this area during the course of SAE conferences in Phoenix during the period 1998 to 2000. The authors who contributed to the present article come from LuK/Sanden and Obrist Engineering, both of which work closely with Audi, BMW, DaimlerChrysler, Volkswagen and their suppliers to develop components and processes. (orig.) [German] Die Ankuendigung von Toyota, umweltfreundliche und leistungsfaehige Klimaanlagen mit dem Kaeltemittel R744 ab 2003 serienmaessig einzusetzen, bestaetigt einen weltweiten Trend. Auch die deutschen Wettbewerber haben - unter anderem im Verlauf von SAE-Veranstaltungen in Phoenix in den Jahren 1998 bis 2000 - ihre Entwicklungsleistungen auf diesem Gebiet dokumentiert. Das Autorenteam besteht aus Mitarbeitern der Firmen LuK/Sanden und Obrist Engineering, die in enger Zusammenarbeit mit Audi, BMW, DaimlerChrysler, Volkswagen und deren Zulieferern Komponenten und Prozesse fuer zukuenftige Klimaanlagen entwickeln. (orig.)

  7. Outbreak of carbon tetrachloride poisoning in a color printing factory related to the use of isopropyl alcohol and an air conditioning system in Taiwan.

    Science.gov (United States)

    Deng, J F; Wang, J D; Shih, T S; Lan, F L

    1987-01-01

    Three workers from a color printing factory were admitted to community hospitals in 1985 with manifestations of acute hepatitis. One of the three had superimposed acute renal failure and pulmonary edema. An investigation was subsequently conducted at the plant to determine the etiology of the outbreak and the prevalence of liver disease among the remaining workers. Comprehensive medical evaluations were conducted, which included physical examinations, liver function tests, and serological screening for hepatitis. Seventeen of 25 workers from the plant had abnormal liver function tests 10 days after the outbreak, and a significant association was found between the presence of abnormal liver function tests and a history of recently having worked inside any of three rooms in which an interconnecting air conditioning system had been installed to cool the printing machines. After further investigation, it was determined that the incident occurred following inadvertent use of carbon tetrachloride to clean a pump in the printing machine. A simulation of the pump cleaning operation revealed ambient air levels of carbon tetrachloride of 300-500 ppm. Ultimately, it was concluded that the outbreak was in all likelihood due to the combined use of carbon tetrachloride and isopropyl alcohol in the cleaning operation. This outbreak underscores the importance of adopting appropriate industrial hygiene measures in a rapidly industrializing nation such as Taiwan.

  8. A CO{sub 2} air conditioning system to fight against greenhouse effect; Une climatisation a CO{sub 2} pour lutter contre l'effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-10-05

    Automotive air-conditioning systems, with the induced additional fuel consumption and with the type of refrigerants used, contribute to the global warming. Several car fitters, like Delphi, have developed prototypes of CO{sub 2} air conditioners. CO{sub 2} is a greenhouse gas but is less harmful for the environment than other classical refrigerants. The use of CO{sub 2} needs a complete re-design of air-conditioning systems which have to stand pressures of 130 bars and temperatures of 165 deg. C. Short paper. (J.S.)

  9. Estudio sobre el almacenamiento de agua helada en los sistemas de climatización centralizados; Study about cooling water storage in centralized air conditioning system

    Directory of Open Access Journals (Sweden)

    Mario Espín Pérez

    2015-04-01

    Full Text Available El desarrollo de este artículo se basa en el estudio del almacenamiento de agua helada en los sistemas de climatización. Para desplazar el consumo eléctrico fuera del horario pico, como herramienta para pretender  incrementar  la eficiencia energética y disminuir el costo de la energía eléctrica en los hoteles con clima tropical. Para ello se procede a la estimación del perfil de carga térmica del hotel Jagua mediante el software TRNSYS, diseño y comprobación del sistema de almacenamiento de agua helada incorporado a las condiciones actuales de la instalación mediante modelos matemáticos que describen su funcionamiento. El objetivo es, evaluar e ilustrar los posibles efectos cuantitativos y cualitativos del almacenamiento de agua helada en el sistema de clima centralizado de la edificación. El trabajo que se presenta se enmarca en los esfuerzos para desarrollar el uso de tecnologías sustentables y la evaluación de sistemas industriales asistidos por computadora en Cuba. The development of this paper is based on the study of cold water storage in air conditioning systems. To offset power consumption off-peak, as a tool to increase energy efficiency claim and reduce the cost of electricity in tropical hotels. To do this we proceed to estimate the thermal load profile Jagua by TRNSYS software, system design and testing of chilled water storage built into the current conditions of the system using mathematical models to describe their operation. The objective is to evaluate and illustrate the quantitative and qualitative effects of cold water storage in the building centralized climate system. The work presented is part of the efforts to develop the use of sustainable technologies and evaluation of computer-aided industrial systems in Cuba.

  10. 光伏并网式家用空调系统性能的实验研究%Experimental Investigation on the Performance of Household Air Conditioning System with Grid-connected Photovoltaic Generation

    Institute of Scientific and Technical Information of China (English)

    金听祥; 徐笑锋

    2015-01-01

    With the base of traditional air conditioning system, the grid-connected photovoltaic household air conditioning sys-tem based on the solar photovoltaic power generation technology is designed in this paper. The power with the solar photovoltaic power generation technology is transformed into the household power of 220 V and 50 Hz by inverter. The household air condi-tioning system is then driven by the transformed power and national grid. The performance of the photovoltaic grid-connected household air conditioning system was tested by Enthalpy Difference Lab under the different power ( 100 W, 135 W and 185 W) of solar panels. The experimental results show that under normal cooling conditions, the average power consumption of the air conditioning system with the different power (100 W, 135 W and 185 W) of solar panels are 52 W, 78 W and 104 W lower than that of the traditional air conditioning system respectively. Similarly, energy efficiency ratios of the air conditioning system with the different power (100 W, 135 W and 185 W) of solar panels are 4. 2%, 5. 5% and 10. 2% lower than that of the tra-ditional air conditioning system respectively. Under heating mode, the average power consumption of the air conditioning system with the different power (100 W, 135 W and 185 W) of solar panels are 68 W, 84 W and 116 W lower than that of the tradi-tional air conditioning system, and the coefficients of performances are 6. 4%, 8% and 11% lower than that of the traditional air conditioning system. It can be concluded that the photovoltaic grid-connected household air conditioning system is feasible.%针对目前的家用空调系统,本文设计了一种以太阳能光伏发电技术为基础,与国家电网并网,共同驱动空调工作的系统,称为光伏并网式家用空调系统。利用光伏发电技术,通过逆变器将太阳能提供的电力转变为220 V、50 Hz家用电源,实现与市电电网的并网,来共同驱动空调运行。利用焓差实验室,

  11. Smart Control System to Optimize Time of Use in a Solar-Assisted Air-Conditioning by Ejector for Residential Sector

    Directory of Open Access Journals (Sweden)

    Giovanna Avedian-González

    2018-02-01

    Full Text Available The present work provides a series of theoretical improvements of a control strategy in order to optimize the time of use of solar air-conditioning by an ejector distributed in multiple solar collectors of vacuum tubes for the residential sector, which will allow us to reduce carbon-dioxide emissions, costs and electrical energy consumption. In a solar ejector cooling system, the instability of the solar source of energy causes an operational conflict between the solar thermal system and ejector cooling cycle. A fuzzy control structure for the supervisory ejector cycle and multi-collector control system is developed: the first control is applied to control the mass flow of the generator and the evaporator for different cooling capacities (3, 3.5, 4, 4.5 and 5 kW and set a temperature reference according to the operating conditions; the second is applied to keep a constant temperature power source that feeds the low-grade ejector cooling cycle using R134aas refrigerant. For the present work, the temperature of the generator oscillates between 65 °C and 90 °C, a condenser temperature of 30 °C and an evaporator temperature of 10 °C. For the purpose of optimization, there are different levels of performance for time of use: the Mode 0 (economic gives a performance of 17.55 h, Mode 5 (maximum cooling power 14.86 h and variable mode (variable mode of capacities 16.25 h, on average. Simulations are done in MATLAB-Simulink applying fuzzy logic for a mathematical model of the thermal balance. They are compared with two different types of solar radiation: real radiation and disturbed radiation.

  12. A comparative study of different methods for the generation of tetra-n-butyl ammonium bromide clathrate hydrate slurry in a cold storage air-conditioning system

    International Nuclear Information System (INIS)

    Shi, X.J.; Zhang, P.

    2013-01-01

    Highlights: ► Four kinds of TBAB CHS generation methods are experimentally investigated. ► Accession of CHS into supercooled solution can be helpful to the generation. ► Higher flow rate results in higher energy efficiency of CHS generation. - Abstract: A cold storage air-conditioning system using tetra-n-butyl ammonium bromide (TBAB) clathrate hydrate slurry (CHS) as cold storage medium was built to investigate the high-efficiency method of TBAB CHS generation. In the present study, four kinds of different TBAB CHS generation methods were experimentally investigated and compared, and these methods included continuously cooling, turning off refrigerator while crystals appearing, supercooling release and accession of TBAB CHS into supercooled TBAB aqueous solution. The results showed that continuously cooling would lead to severe adhesion of crystal to the heat exchanger wall, and supercooling release took place with a big stochastic characteristic, hence the first and third method were concluded not reliable. Both the second and fourth methods could maintain the temperature of heat exchanger wall at a relatively higher level, therefore the crystal adhesion to the heat exchanger wall would be reduced significantly, which led to higher coefficient of performance (COP). In addition, accession of TBAB CHS into TBAB supercooled solution could shorten the time of supercooling release, resulting in about 21.8–35.4% shorter generation time than other methods. Moreover, the influence of flow rate on the CHS generation process was investigated, and the results showed that higher flow rate generally resulted in higher system COP

  13. Articulated, Performance-Based Instruction Objectives Guide for Air Conditioning, Refrigeration, and Heating (Environmental Control System Installer/Servicer). Edition I.

    Science.gov (United States)

    Henderson, William Edward, Jr., Ed.

    This articulation guide contains 17 units of instruction for the first year of a two-year vocational program designed to prepare the high school graduate to install, maintain, and repair various types of residential and commercial heating, air conditioning, and refrigeration equipment. The units are to introduce the student to fundamental theories…

  14. 变温环境室空调系统实验研究%Experimental Study on Air Conditioning System of Variable Temperature Ambient Chamber

    Institute of Scientific and Technical Information of China (English)

    张柱; 吴蔚兰

    2017-01-01

    This paper introduces experimental facilities on air conditioning system of variable temperature ambient chamber.Researching and analysis the operating parameters of temperature distribution,compressor start-stop cycle and cooling capacity and COP changes.The results showed that the closer chamber controlled temperature is located to the ambient temperature,the smaller the temperature fluctuations is,temperature difference is also smaller;compared with the theoretical value,with ambient chamber temperature rising,compressor cooling capacity and COP rise;theoretical cooling capacity is more than the actual cooling capacity and compression of the start-stop,regardless of the theoretical value or experimental values,showed a downward trend from low to high,but the low temperature test values close to the theoretical value,when the high temperature is lower than the theoretical value.%介绍了变温环境室空调系统实验装置,研究分析了不同工况下室内温度分布、压缩机启停周期、制冷量及COP等运行参数的变化情况.实验结果表明:室内控制温度越接近坐落环境温度,温度波动幅度越小,不同位置的温差也越小;与理论值相比,压缩机的制冷量及COP随环境室温度升高而升高,理论制冷量大于实际制冷量;而压缩机启停比,无论理论值还是实验值,均呈现从低温到高温下降的趋势,但低温时实验值接近于理论值,高温时低于理论值.

  15. Applied Horizontal and Vertical Geothermal Heat Exchanger with Heat Pump System to Provide Air Conditioning for an Academic Facility in Mexico

    Directory of Open Access Journals (Sweden)

    Daniel Alcantar Martínez

    2017-07-01

    Full Text Available At present in Mexico, the renewable energy has become more important due to the great dependence of the country for fossil fuels. Within the several applications of renewable energy, there are the geothermal applications for the air conditioning of spaces. This technology employs heat pumps that interexchange heat with the ground. This technology is relatively young in Mexico, leaving a large field for study and application throughout the country. In this way, to calculate the correct sizing of geothermal heat exchangers, it is necessary to calculate the thermal loads of the complex in which this technology of geothermal heat pumps using vertical heat exchangers type U will be installed, to perform the calculation of thermal loads Autodesk Revit® software was used, with which was possible to make a virtual model in detail of the botanical center that is located in Morelia, Michoacán, Mexico and belongs to the Universidad Michoacana de San Nicolás de Hidalgo (UMNSH. This study shows the results of the analysis of the installations and determination of the thermal loads of the complex due to this type of infrastructure. By obtaining the values of the thermal loads, the dimensioning of the heat exchanger was archived, which will have to be installed to cover the thermal requirement of this system and his installation, in addition to the selection of the heat pump. This complex of 2 levels, where, on the first floor there are cubicles and laboratories and on the second floor, several common areas. The design was developed in detail in Autodesk Revit 2015. After obtaining the thermal loads, the GLHEPro software was used for dimensioning the Vertical heat exchangers with the number and depth of the exchangers was obtained. the GLD 2014 software was used for dimensioning the Horizontal heat exchangers with the number and depth of the exchangers was obtained.

  16. Effect of enhanced ultraviolet germicidal irradiation in the heating ventilation and air conditioning system on ventilator-associated pneumonia in a neonatal intensive care unit.

    Science.gov (United States)

    Ryan, R M; Wilding, G E; Wynn, R J; Welliver, R C; Holm, B A; Leach, C L

    2011-09-01

    The objective of this study was to test the hypothesis that enhanced ultraviolet germicidal irradiation (eUVGI) installed in our neonatal intensive care unit (NICU) heating ventilation and air conditioning system (HVAC) would decrease HVAC and NICU environment microbes, tracheal colonization and ventilator-associated pneumonia (VAP). The study was designed as a prospective interventional pre- and post-single-center study. University-affiliated Regional Perinatal Center NICU. Intubated patients in the NICU were evaluated for colonization, and a high-risk sub-population of infants <30 weeks gestation ventilated for ≥ 14 days was studied for VAP. eUVGI was installed in the NICU's remote HVACs. The HVACs, NICU environment and intubated patients' tracheas were cultured pre- and post-eUVGI for 12 months. The high-risk patients were studied for VAP (positive bacterial tracheal culture, increased ventilator support, worsening chest radiograph and ≥ 7 days of antibiotics). Pseudomonas, Klebsiella, Serratia, Acinetobacter, Staphylococcus aureus and Coagulase-negative Staphylococcus species were cultured from all sites. eUVGI significantly decreased HVAC organisms (baseline 500,000 CFU cm(-2); P=0.015) and NICU environmental microbes (P<0.0001). Tracheal microbial loads decreased 45% (P=0.004), and fewer patients became colonized. VAP in the high-risk cohort fell from 74% (n=31) to 39% (n=18), P=0.04. VAP episodes per patient decreased (Control: 1.2 to eUVGI: 0.4; P=0.004), and antibiotic usage was 62% less (P=0.013). eUVGI decreased HVAC microbial colonization and was associated with reduced NICU environment and tracheal microbial colonization. Significant reductions in VAP and antibiotic use were also associated with eUVGI in this single-center study. Large randomized multicenter trials are needed.

  17. Uniform semiclassical approximation for absorptive scattering systems

    International Nuclear Information System (INIS)

    Hussein, M.S.; Pato, M.P.

    1987-07-01

    The uniform semiclassical approximation of the elastic scattering amplitude is generalized to absorptive systems. An integral equation is derived which connects the absorption modified amplitude to the absorption free one. Division of the amplitude into a diffractive and refractive components is then made possible. (Author) [pt

  18. Low-Flow Liquid Desiccant Air Conditioning: General Guidance and Site Considerations

    Energy Technology Data Exchange (ETDEWEB)

    Kozubal, E.; Herrmann, L.; Deru, M.; Clark, J.

    2014-09-01

    Dehumidification or latent cooling in buildings is an area of growing interest that has been identified as needing more research and improved technologies for higher performance. Heating, ventilating, and air-conditioning (HVAC) systems typically expend excessive energy by using overcool-and-reheat strategies to dehumidify buildings. These systems first overcool ventilation air to remove moisture and then reheat the air to meet comfort requirements. Another common strategy incorporates solid desiccant rotors that remove moisture from the air more efficiently; however, these systems increase fan energy consumption because of the high airside pressure drop of solid desiccant rotors and can add heat of absorption to the ventilation air. Alternatively, liquid desiccant air-conditioning (LDAC) technology provides an innovative dehumidification solution that: (1) eliminates the need for overcooling and reheating from traditional cooling systems; and (2) avoids the increased fan energy and air heating from solid desiccant rotor systems.

  19. Performance Evaluation of Photovoltaic Solar Air Conditioning

    Directory of Open Access Journals (Sweden)

    Snegirjovs A.

    2016-12-01

    Full Text Available Information on the electrical-driven solar air conditioning (SAC is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW. In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

  20. Performance Evaluation of Photovoltaic Solar Air Conditioning

    Science.gov (United States)

    Snegirjovs, A.; Shipkovs, P.; Lebedeva, K.; Kashkarova, G.; Migla, L.; Gantenbein, P.; Omlin, L.

    2016-12-01

    Information on the electrical-driven solar air conditioning (SAC) is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC) systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average) systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW). In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

  1. PROSPECTS FOR THE DEVELOPMENT OF TECHNOLOGY AIR CONDITIONING

    Directory of Open Access Journals (Sweden)

    O. V. Chernyshova

    2008-03-01

    Full Text Available In the article the evaporation cooling and spray (aqueous and air-to-water types of the air-conditioning systems are considered, their merits and demerits are analyzed; the new scheme of a conditioner is offered.

  2. A mixed air/air and air/water heat pump system ensures the air-conditioning of a cinema; Un systeme mixte PAC air/air et air/eau climatise un cinema

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-03-01

    This article presents the air conditioning system of a new cinema complex of Boulogne (92, France) which comprises a double-flux air processing plant and two heat pumps. Each heat pump has two independent refrigerating loops: one with a air condenser and the other with a water condenser. This system allows to limit the power of the loop and to reduce the size of the cooling tower and of the vertical ducts. This article describes the technical characteristics of the installation: thermodynamic units, smoke clearing, temperature control, air renewing. (J.S.)

  3. Optimization of air conditioning systems utilizing low temperature thermal storage; Optimizacion de sistemas de acondicionamiento de aire utilizando sistemas de almacenamiento termico de baja temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Contreras Ramirez, J.; Dorantes Rodriguez, R. [Departamento de Energia, Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D. F. (Mexico)

    1997-12-31

    In the last few years the different projects on the saving and efficient use of energy in the tertiary sector have been demonstrating the existing great potential in the air conditioning systems and equipment, whose intensive use is due to the predominance of hot and dry and hot and humid climate prevailing in a large part of the Mexican territory. Without any doubts one of the most serious problems facing the complex management and optimization of these systems is related to the variability of the thermal load and the regulation possibilities of the thermal machines, so as to attain, along the day an appropriate use and optimization of the total installed load, with the best possible economic benefits. Among the strategies that allow the optimization of the installed capacity and the variability of the thermal load is the low temperature thermal storage, for instance, the storage of ice, which is produced and stored to be used when the cooling machines are in standby in order to use this stored energy during the peak hours and during the normal operation of the equipment, but diminishing in a significant amount the electrical demand of the system to satisfy the thermal load with a combination thermal storage-cooling machine. This paper presents some case histories and the type of thermal storage commonly used; a methodology is discussed that allows to determine technically as well as economically the size of a thermal storage room. Some problems in the control and operation of these thermal systems are also presented. [Espanol] En los ultimos anos los diversos proyectos sobre ahorro y uso eficiente de la energia en el sector terciario han venido mostrando el gran potencial existente en los sistemas y equipos de aire acondicionado, cuyo uso intensivo se debe al predominio de los climas calidos seco y calido humedo en buena parte del territorio nacional. Sin lugar a dudas uno de los problemas mas serios que enfrenta la compleja gestion y optimizacion de estos

  4. Optimization of air conditioning systems utilizing low temperature thermal storage; Optimizacion de sistemas de acondicionamiento de aire utilizando sistemas de almacenamiento termico de baja temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Contreras Ramirez, J; Dorantes Rodriguez, R [Departamento de Energia, Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D. F. (Mexico)

    1998-12-31

    In the last few years the different projects on the saving and efficient use of energy in the tertiary sector have been demonstrating the existing great potential in the air conditioning systems and equipment, whose intensive use is due to the predominance of hot and dry and hot and humid climate prevailing in a large part of the Mexican territory. Without any doubts one of the most serious problems facing the complex management and optimization of these systems is related to the variability of the thermal load and the regulation possibilities of the thermal machines, so as to attain, along the day an appropriate use and optimization of the total installed load, with the best possible economic benefits. Among the strategies that allow the optimization of the installed capacity and the variability of the thermal load is the low temperature thermal storage, for instance, the storage of ice, which is produced and stored to be used when the cooling machines are in standby in order to use this stored energy during the peak hours and during the normal operation of the equipment, but diminishing in a significant amount the electrical demand of the system to satisfy the thermal load with a combination thermal storage-cooling machine. This paper presents some case histories and the type of thermal storage commonly used; a methodology is discussed that allows to determine technically as well as economically the size of a thermal storage room. Some problems in the control and operation of these thermal systems are also presented. [Espanol] En los ultimos anos los diversos proyectos sobre ahorro y uso eficiente de la energia en el sector terciario han venido mostrando el gran potencial existente en los sistemas y equipos de aire acondicionado, cuyo uso intensivo se debe al predominio de los climas calidos seco y calido humedo en buena parte del territorio nacional. Sin lugar a dudas uno de los problemas mas serios que enfrenta la compleja gestion y optimizacion de estos

  5. Development of technology and systems for air-conditioned and cogenerations using natural gas; Desenvolvimento de tecnologia e sistemas para climatizaco e cogeracao usando gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Carlos Antonio Cabral dos; Varani, Celina Maria Ribeiro [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Lab. de Energia Solar; Campos, Michel Fabianski [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This preset work deal with a technological project that has as main objective the development of national technology in absorption refrigeration for application in the human thermal comfort with natural gas as energy source in direct fired or through energy recuperation of the combustion gases in cogeneration systems. This project makes part of the REDEGASENERGY and also receive financial support from CT-PETRO founds through FINEP, and also has as partner the local gas distributed company. The focus to be reached is the obtaining of a system of double effect using the solution pair Water-Lithium Bromide as work fluid to the capacity range of five to fifty tons of refrigeration. This range means a important branch on the market for minis-shopping, medical clinics, conveniences shopping, small hotels, motels, etc. The system is compound basically of heat exchangers: vapor generator, absorber, condenser, evaporator and intermediary exchanger. The design of the system is based on the thermodynamic, heat and mass analyses for each component. The concepts of exergy and irreversibility are used for through second thermodynamic law to realize the exegetic analysis and to identify the points of the most thermal lost. The correction on the identified components allows the improvements on the performance of each components and all system. As proposed steps to reach the final objective is established first the development of a single effect system operating in similar conditions of capacity and work fluid that the intended double effect system. (author)

  6. Air Conditioner Charging. Automotive Mechanics. Air Conditioning. Instructor's Guide [and] Student Guide.

    Science.gov (United States)

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automobile air conditioning, consists of a student guide and an instructor guide dealing with air conditioning charging. Covered in the module are checking the air conditioning system for leaks, checking and adding refrigerant oil as needed, evacuating the system,…

  7. FY 1977 Annual report on Sunshine Project results. Research and development of solar energy systems for air conditioning and hot water supply (Research and development of systems for large buildings); 1977 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Ogata kenchikubutsuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-03-31

    This project is aimed at development of (1) devices for solar energy systems for air conditioning and hot water supply, and (2) low-cost, safe systems incorporating the above devices, which are easily inspected and maintained, in which optimum buildings for effective utilization of solar energy are also investigated. Precision of the system analysis is improved by feeding back the results obtained by the basic studies conducted so far into the simulation. The technical supports for commercialization of heat collectors, refrigerators, heat-storage tanks and radiation type ceilings are also obtained. These results are combined for the designs of a real-size test building. In this year, works to install the facilities in the Oita University's test building are completed. These facilities include 40 units of large-size heat collectors (each approximately 2 m by 7.5 m in size); an absorption refrigerator of 30 uSRT in which single- and double-effect systems are combined; 2 piston-flow type heat-storage tanks, each 45 m{sup 3} in capacity; and others including analyzer, associated piping, duct, instrumentation and electrical systems. The test runs are conducted for the control systems, and long- and short-term instrumentation systems to draw the test schedules for optimizing the full-scale runs to be conducted in the next year. The operating and instrumentation manuals, and operating schedules are also drawn. (NEDO)

  8. Experimental assessment of an absorption cooling system operating with the ammonia/lithium nitrate mixture

    International Nuclear Information System (INIS)

    Hernández-Magallanes, J.A.; Domínguez-Inzunza, L.A.; Gutiérrez-Urueta, G.; Soto, P.; Jiménez, C.; Rivera, W.

    2014-01-01

    This paper reports the experimental results of a single effect absorption cooling system of 3 kW of nominal cooling capacity operating with ammonia–lithium nitrate solution. The system was designed and built in the Instituto de Energías Renovables of the Universidad Nacional Autónoma de México and can be used for food conservation or air conditioning. The absorber and generator are falling film heat exchangers. The condenser, evaporator and solution heat exchanger are compact plate heat exchangers. The heat was supplied to the generator at temperatures between 85 °C and 105 °C, while the cooling water temperatures to remove the heat produced during the condensation and absorption varied between 18 °C and 36 °C. The results showed that the system can produce up to 2.7 kW of cooling capacity at heating water temperatures of 95 °C and can achieve evaporator temperatures as low as 1 °C. The experimental coefficients of performance varied between 0.45 and 0.70. Because of the developed system do not need a rectifier and reasonable good coefficients of performance were achieved, the developed system seems to be a good alternative to be used for food conservation or air conditioning. - Highlights: • An absorption cooling system was developed using NH 3 –LiNO 3 . • The achieved COP (coefficients of performance) are the highest reported for a system using NH 3 –LiNO 3 . • Evaporator temperatures as low as 1 °C were achieved. • COP varied between 0.45 and 0.7. • The developed system seems to be a good alternative for food conservation and air conditioning

  9. 2011 German refrigeration and air conditioning meeting. Proceedings; Deutsche Kaelte-Klima-Tagung 2011. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Within the DKV conference of the Deutscher Kaelte- und Klimatechnischer Verein e.V. (Hanover, Federal Republic of Germany) from 16th to 18th November, 2011, at the Eurogress Aachen (Federal Republic of Germany) 112 lectures were held according to the following themes: cryomedicine, cryobiology, cryocomponents, mobility, cryoapplications, miniature cooler, Fundamentals and materials in the cryotechnology and heat pump technology, heat transfer, absorption processes, materials characteristics and phase change materials, storage and phase change, plants and components of refrigerating and heat pump technology - compressors, control and systems, energy efficiency (and CO{sub 2}), standardization and standard, application of refrigeration, supermarket/coolant, enhancement of efficiency in the air conditioning of passenger cars, indoor air conditioning in automobiles, enhancement of efficiency in different vehicles, climate technology and application of heat pumps - field tests and optimization, test rigs and simulations, heat pumps, optimisation in new buildings and stock buildings, climate coolants and quality of air. Beside this conference twelve student meetings were presented.

  10. Evaluation of saving measurements and energetic efficiency in air-conditioning systems; Evaluacion de medidas de ahorro y eficiencia energetica en sistemas de climatizacion

    Energy Technology Data Exchange (ETDEWEB)

    Perez Lombard, L [Asociacion de Investigacion y Cooperacion de Andalucia (Spain); Ortiz, J [Building Research Establishment (United Kingdom); Riviere, P [Armines-ecole des mines de Paris (France)

    2006-04-15

    Buildings require an adequate air conditioning to offer workers a labor environment where there is thermal comfort. A study was performed in three different European places which count on several climates. The conclusion was the following: in order to analyze the energy efficiency in edifications it is fundamental the simulation tools use with the purpose of calculating the consumption and evaluating the saving measurements. [Spanish] Los edificios requieren de una climatizacion adecuada para que los que ahi operan puedan hacerlo dentro de un ambiente laboral donde exista el confort termico. Se llevo a cabo un estudio en tres lugares de Europa poseedores de diferentes climas y se concluyo que para poder analizar la eficiencia energetica de climatizacion en las edificaciones es imprescindible el uso de herramientas de simulacion con el proposito de calcular el consumo y evaluar las medidas de ahorro.

  11. SESSA: Expert system for the selection of air conditioning equipment; SESEAA: Sistema experto para la seleccion de equipos de aire acondicionado

    Energy Technology Data Exchange (ETDEWEB)

    Kemper Valverde, Nicolas; Cardenas Perez, Edgar [Laboratorio de Sistemas Inteligentes, Centro de Instrumentos de la Universidad Nacional Autonoma de Mexico (UNAM), Mexico, D. F. (Mexico)

    1998-12-31

    The problem of selecting air conditioning and refrigeration equipment is quite wide and complex, since it encompasses from the application of the basic principles of physics and of thermodynamics up to the classic engineering design problems; these in turn can be numberless since they vary from place to place depending on multiple factors such as the region geographic and economic conditions. On the other hand, account most be taken of several elements such as windows, walls, and its specific geographical orientation, roofs, floors, partitions, equipment, lighting, etc., all this exerts influence in the complexity that represents the selection process. This paper describes a useful informatics tool to make it easy the selection process in air conditioning installations, taking into account multiple saving and efficient use of energy criteria, reflected in the operation process of these installations. [Espanol] El problema de seleccion de sistemas de aire acondicionado y de refrigeracion es bastante amplio y complejo, ya que abarca desde la aplicacion de los principios basicos de la fisica y la termodinamica hasta los problemas clasicos de diseno de ingenieria; estos a la vez pueden ser innumerables ya que varian de un lugar a otro y de un proyecto a otro, dependiendo de multiples factores tales como las condiciones geograficas y economicas de la region. Por otra parte se deben tomar en cuenta diversos elementos como son: ventanas, muros y sus orientaciones especificas, techos, pisos, particiones, equipos, iluminacion, etc., todo esto influye en la complejidad que representa el proceso de seleccion. En el presente trabajo se describe una herramienta informatica para facilitar el proceso de seleccion de instalaciones de aire acondicionado, tomando en cuenta multiples criterios de ahorro y uso eficiente de energia que se reflejan durante el proceso de operacion de estas instalaciones.

  12. SESSA: Expert system for the selection of air conditioning equipment; SESEAA: Sistema experto para la seleccion de equipos de aire acondicionado

    Energy Technology Data Exchange (ETDEWEB)

    Kemper Valverde, Nicolas; Cardenas Perez, Edgar [Laboratorio de Sistemas Inteligentes, Centro de Instrumentos de la Universidad Nacional Autonoma de Mexico (UNAM), Mexico, D. F. (Mexico)

    1999-12-31

    The problem of selecting air conditioning and refrigeration equipment is quite wide and complex, since it encompasses from the application of the basic principles of physics and of thermodynamics up to the classic engineering design problems; these in turn can be numberless since they vary from place to place depending on multiple factors such as the region geographic and economic conditions. On the other hand, account most be taken of several elements such as windows, walls, and its specific geographical orientation, roofs, floors, partitions, equipment, lighting, etc., all this exerts influence in the complexity that represents the selection process. This paper describes a useful informatics tool to make it easy the selection process in air conditioning installations, taking into account multiple saving and efficient use of energy criteria, reflected in the operation process of these installations. [Espanol] El problema de seleccion de sistemas de aire acondicionado y de refrigeracion es bastante amplio y complejo, ya que abarca desde la aplicacion de los principios basicos de la fisica y la termodinamica hasta los problemas clasicos de diseno de ingenieria; estos a la vez pueden ser innumerables ya que varian de un lugar a otro y de un proyecto a otro, dependiendo de multiples factores tales como las condiciones geograficas y economicas de la region. Por otra parte se deben tomar en cuenta diversos elementos como son: ventanas, muros y sus orientaciones especificas, techos, pisos, particiones, equipos, iluminacion, etc., todo esto influye en la complejidad que representa el proceso de seleccion. En el presente trabajo se describe una herramienta informatica para facilitar el proceso de seleccion de instalaciones de aire acondicionado, tomando en cuenta multiples criterios de ahorro y uso eficiente de energia que se reflejan durante el proceso de operacion de estas instalaciones.

  13. Current status of and problems in ice heat storage systems contributing to improving load rate. Air conditioning system utilizing ice heat storage and building frame storage (Takenaka Corporation); Fukaritsu kaizen ni kokensuru kori chikunetsu system no genjo to kadai. Kori chikunetsu to kutai chikunetsu wo riyoshita kucho system

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Y.; Yoshitake, Y. [Takenaka Corp., Osaka (Japan)

    1998-02-01

    Development was made on a new air conditioning system, `building frame heat storage air conditioning system`, which combines an ice heat storage system with a building frame heat storage. With the building frame heat storage system, a damper is installed on an indoor device to blow cold air from the air conditioner onto slabs on the upper floor during nighttime power generating period. Heat is stored in beams, pillars and walls, and the shell absorbs and dissipates heat during daytime. Since general office buildings consume primary energy at 22.8% for heat source and 26.9% for transportation, which is greater, a natural coolant circulation type air conditioning system was developed as an air conditioning system for the secondary side. This made the building frame heat regeneration possible for the first time. With regard to heat storage quantity and heat dissipation quantity, the quantity of heat which can be stored during nighttime (10 hours) and dissipated during air conditioning using period in daytime (10 hours) is 80% of the stored heat quantity. This system was installed in a building in Kobe City. As a result of the measurement, it was found that indoor heat load reduction rate as a result of using the building frame heat storage was 24% or more in summer and 80% or more in winter. 7 figs., 2 tabs.

  14. Performance modelling and simulation of an absorption solar cooling system for Malaysia

    International Nuclear Information System (INIS)

    Assilzadeh, F.; Ali, Y.; Kamaruzzaman Sopian

    2006-01-01

    Solar radiation contains huge amounts of energy and is required for almost all the natural processes on earth. Solar-powered air-conditioning has many advantages when compared to normal electricity system. This paper presents a solar cooling system that has been designed for Malaysia and other tropical regions using evacuated tube solar collector and LiBr absorption system. A modelling and simulation of absorption solar cooling system is modeled in Transient System Simulation (TRNSYS) environment. The typical meteorological year file containing the weather parameters is used to simulate the system. Then a system optimization is carried out in order to select the appropriate type of collector, the optimum size of storage tank, the optimum collector slope and area and the optimum thermostat setting of the auxiliary boiler

  15. Systemic Absorption of Nanomaterials by Oral Exposure

    DEFF Research Database (Denmark)

    Binderup, Mona-Lise; Bredsdorff, Lea; Beltoft, Vibe Meister

    This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches.......This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches....

  16. Air-Conditioning for Electric Vehicles

    Science.gov (United States)

    Popinski, Z.

    1984-01-01

    Combination of ammonia-absorption refrigerator, roof-mounted solar collectors, and 200 degrees C service electric-vehicle motor provides evaporative space-heating/space cooling system for electric-powered and hybrid fuel/electric vehicles.

  17. Solar-Driven Air-Conditioning Cycles: A Review

    Directory of Open Access Journals (Sweden)

    A. M. Abu-Zour

    2007-12-01

    Full Text Available Most conventional cooling/refrigeration systems are driven by fossil fuel combustion, and therefore give rise to emission of environmentally damaging pollutants. In addition, many cooling systems employ refrigerants, which are also harmful to the environment in terms of their Global Warming Potential (GWP and Ozone Depletion Potential (ODP. Development of a passive or hybrid solar-driven air-conditioning system is therefore of interest as exploitation of such systems would reduce the demand for grid electricity particularly at times of peak load. This paper presents a review of various cooling cycles and summarises work carried out on solar-driven air-conditioning systems.

  18. The Future of Air Conditioning for Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Burlington, MA (United States); Guernsey, Matt [Navigant Consulting, Burlington, MA (United States); Young, Jim [Navigant Consulting, Burlington, MA (United States); Fujrman, Jay [Navigant Consulting, Burlington, MA (United States); Abdelaziz, Amar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-07-01

    BTO works with researchers and industry to develop and deploy technologies that can substantially reduce energy consumption and greenhouse gas (GHG) emissions in residential and commercial buildings. Air conditioning systems in buildings contribute to GHG emissions both directly through refrigerant emissions, as well as indirectly through fossil fuel combustion for power generation. BTO promotes pre-competitive research and development on next-generation HVAC technologies that support the phase down of hydrofluorocarbon (HFC) production and consumption, as well as cost-effective energy efficiency improvements. DOE provides, with this report, a fact-based vision for the future of A/C use around the world. DOE intends for this vision to reflect a broad and balanced aggregation of perspectives. DOE brings together this content in an effort to support dialogue within the international community and help keep key facts and objectives at the forefront among the many important discussions.

  19. Aircraft Environmental System Mechanic, 2-9. Block II--Air Conditioning Systems. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This publication contains a teaching guide and student instructional materials for conducting a high school or adult vocational education course to train persons to perform duties as an aircraft environmental systems mechanic. Course content has been adapted from a military course. The instructional design for this course is self-pace and/or small…

  20. Impact of surface disinfection and sterile draping of furniture on room air quality in a cardiac procedure room with a ventilation and air-conditioning system (extrusion airflow, cleanroom class 1b (DIN 1946-4)).

    Science.gov (United States)

    Below, Harald; Ryll, Sylvia; Empen, Klaus; Dornquast, Tina; Felix, Stefan; Rosenau, Heike; Kramer, Sebastian; Kramer, Axel

    2010-09-21

    In a cardiac procedure room, ventilated by a ventilation and air-conditioning system with turbulent mixed airflow, a protection zone in the operating area could be defined through visualization of airflows. Within this protection zone, no turbulence was detectable in the room air.Under the given conditions, disinfection of all surfaces including all furniture and equipment after the last operation and subsequent draping of furniture and all equipment that could not be removed from the room with sterile surgical drapes improved the indoor room air quality from cleanroom class C to cleanroom class B. This also allows procedures with elevated requirements to be performed in room class 1b.

  1. Renewable energies dossier. The early beginnings of a change in the building trade. Outstanding evolutions presented at ISH 2001. A development still bounded by the economic sustain of the government. Something new under the sun. Looking for alternate solutions for air-conditioning. A photovoltaic project for developing countries. The solar absorption improves the Banyuls wine. A thermal solar collector for the production of sanitary hot water in Ile-de-France; Dossier energies renouvelables. Les premices d'un mouvement dans le batiment. Des evolutions marquantes presentees a ISH 2001. Un developpemnt encore lie au soutien economique de l'etat. Du nouveau sous le soleil. A la recherche de solutions alternatives pour la climatisation. Un projet photovoltaique pour les pays en voie de developpement. L'absorption solaire bonifie le banyuls. Un capteur solaire thermique pour l'ECS en Ile-de-France

    Energy Technology Data Exchange (ETDEWEB)

    Sappa, F.; Grumel, N.; Haentjens, H.

    2001-07-01

    The fight against greenhouse gas emissions implies to favor the development and use of renewable energies and to reduce the consumption of fossil fuels. The professionals of the building trade are of course concerned by such actions but unfortunately only few space heating/cooling or air-conditioning installations use renewable energies. In France, only one solar absorption air-conditioning installation exists (at Banyuls, Pyrenees Orientales) and the Bordeaux airport is one of the only buildings supplied with a tri-generation unit. This dossier makes a prospective analysis of the existing techniques that would be used in tomorrow's air-conditioning. It comprises 8 articles dealing with: the early beginnings of the use of renewable energies in the building trade and the inventory of existing techniques: solar thermal, cogeneration, tri-generation (electricity, heat and coldness), fuel cells (electrochemical reaction); the outstanding products presented at Frankfurt during the 2001 edition of the ISH exhibition (absorption heat pumps, heat pump with zeolite and water as refrigerant, solar heaters, hybrid systems, condensation boilers, fuel cells..); the bad competitiveness of renewable energies and the necessary financial sustain of the government; the start-up of the 'sun plan' program by the French agency of environment and energy mastery (Ademe) for the development of solar thermal energy in the residential sector; the 'know-how technical notes' edited by the scientific and technical committee of environment industries (Costic) for the development of low energy consumption air-conditioning processes (dry cooling, evaporation cooling, recovery of heat losses etc..); the project of development of photovoltaic cooling systems for developing countries (evaporative cooling or buried pipes); the unique French solar wine ageing cellar of Banyuls (3500 m{sup 2}, 15000 m{sup 3}, 3 levels); the thermal solar collector of the Quality Hotel of Rosny

  2. FY 1977 Annual report on Sunshine Project results. Research on solar energy systems for air conditioning and hot water supply; 1977 nendo taiyo netsu reidanbo kyuto system no kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-03-31

    This project is aimed at research and development of utilization of solar energy for air conditioning and hot water supply, as part of the researches on systems under Sunshine Project for utilization of solar energy. This project is focused on the research items, selected from those pursued by the 3-year project beginning in FY1974 as the ones considered to be important for the future diffusion and promotion of the systems for utilization of solar energy. The 3-year project has produced the software and hardware results, based on development of the devices and construction of a solar house. At this stage of time, it is pointed out that studies on economic viability of the system, development of the software for diffusion of the solar systems, and development of new, more suitable systems and methods for utilization of solar energy are important. In this fiscal year, the four themes (studies on economic viability of the conceptual solar system designs, simplified methods for designing the systems, evaluation of system performance, and studies on energy-saving effects and economic viability) are taken up, viewed from development of the software for diffusion and promotion of the systems for utilizing solar energy, based on the results obtained by the previous 3-year project. (NEDO)

  3. Developed adaptive neuro-fuzzy algorithm to control air conditioning ...

    African Journals Online (AJOL)

    The paper developed artificial intelligence technique adaptive neuro-fuzzy controller for air conditioning systems at different pressures. The first order Sugeno fuzzy inference system was implemented and utilized for modeling and controller design. In addition, the estimation of the heat transfer rate and water mass flow rate ...

  4. FY 1977 Annual report on Sunshine Project results. Research and development of solar energy systems for air conditioning and hot water supply (Research and development of glass-based materials); 1977 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Glass kei zairyo no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-05-01

    This project is aimed at development of the following collector techniques for various types of solar energy systems for air conditioning and hot water supply: (1) selective transmission glass, (2) reflection-preventive glass, (3) glass-based selective absorption film, and (4) high-performance collector. For the item (1), the STG coated with a reflection-preventive film of In{sub 2}O{sub 3} and that with MgF{sub 2} attain the target performance, and high-speed sputtering is investigated for development of the mass production techniques and promising results are produced. For the item (2), formation of a uniform reflection-preventive film on the glass's front surface and improvement of the reproducibility are investigated, and promising results are produced. For the item (3), a selective absorption plane having a solar radiation absorptivity of 0.90 or more and infrared emissivity of 0.30 or less is produced by baking a SnO{sub 2} film on a soft steel plate undercoated with a black glaze as the glass-based film. For the item (4), a total of 4 types of collectors are fabricated on a trial basis and tested for their heat-collecting performance; a honeycomb type with the selective absorption film, modified laminated type with changed pipe arrangement, one using a large-size reflection-preventive glass, and another one with changed method for supporting the heat-collecting plate. Attainable performance level of the flat plate type collector for commercial purposes is estimated, and the specifications of the commercial collector as the research target are determined. (NEDO)

  5. Refrigeration and air-conditioning

    CERN Document Server

    Hundy, G H; Welch, T C

    2008-01-01

    Now in its fourth edition, this respected text delivers a comprehensive introduction to the principles and practice of refrigeration. Clear and straightforward, it is designed for students (NVQ/vocational level) and professional HVAC engineers, including those on short or CPD courses. Inexperienced readers are provided with a comprehensive introduction to the fundamentals of the technology. With its concise style yet broad sweep the book covers most of the applications professionals will encounter, enabling them to understand, specify, commission, use and maintain these systems. Many readers w

  6. Support of the launching of motor car air conditioning systems with the coolant CO{sub 2} (R744). Test bench measurements and practical trials; Unterstuetzung der Markteinfuehrung von Pkw-Klimaanlagen mit dem Kaeltemittel CO{sub 2} (R744). Pruefstandsmessungen und Praxistest

    Energy Technology Data Exchange (ETDEWEB)

    Lemke, Nicholas; Mildenberger, Julia [Technische Univ. Braunschweig (Germany); Graz, Martin [Obrist Engineering GmbH, Lustenau (Austria)

    2011-10-15

    In the research project two passenger car air-conditioning systems were analyzed with regard to cooling capacity and efficiency. The results were compared with one another. The first system was a standard air-conditioning unit using R134a as a refrigerant. As a second system a CO{sub 2} (R744) prototype HVAC unit was used. Both units were investigated on one hand installed in a car on a dynamometer by Obrist Engineering GmbH and on the other hand installed in a calorimetric test rig by Technische Universitaet Braunschweig, Institut fuer Thermodynamik. While the tests in the calorimetric test rig showed comparable efficiencies and cooling capacities for both setups, consumption advantages were determined for the R744- air-conditioning unit installed in the vehicle by the company Obrist. With CO{sub 2} (R744) as a refrigerant for mobile air-conditioning systems an environmental friendly solution is available. (orig.)

  7. Experimental results of a direct air-cooled ammonia–lithium nitrate absorption refrigeration system

    International Nuclear Information System (INIS)

    Llamas-Guillén, S.U.; Cuevas, R.; Best, R.; Gómez, V.H.

    2014-01-01

    Absorption thermal cooling systems driven by renewable energy are a viable option in order to reduce fossil fuel consumption and the associated emissions. This work shows the results of an air cooled absorption cooling prototype working with an ammonia–lithium nitrate mixture at high ambient temperatures. An absorption refrigeration system was designed and built. The prototype is a one stage ammonia–lithium nitrate air cooled chiller. The experimental system was instrumented to evaluate each component. This paper shows the operation conditions in the experimental unit as well as some of the heat loads encountered at different operating conditions. The system was operated successfully at ambient temperatures in the range of 25–35 °C. A series of test showed that even at ambient temperatures it can be operated at evaporator temperatures below 10 °C producing chilled water for air conditioning applications such as radiative cooling panels. The system proved to stabilize very quickly and no risk of crystallization was encountered so the first results are promising in order to continue with the development of a more advanced prototype. - Highlights: •Experimental results of a direct air-cooled ammonia–lithium nitrate system. •The prototype is a one stage ammonia–lithium nitrate air cooled chiller. •The absorption system was operated successfully at ambient temperatures. •Cooling loads of 4.5 kW were reached in the chilled water side

  8. Performance of Active Wave Absorption Systems

    DEFF Research Database (Denmark)

    Hald, Tue; Frigaard, Peter

    on a horisontal and vertical velocity are treated. All three systems are based on digital FIR-filters. For numerical comparison a performance function combining the frequency response of the set of filters for each system is derived enabling discussion on optimal filter design and system setup. Irregular wave......A comparison of wave gauge based on velocity meter based active absorption systems is presented discussing advantages and disadvantages of the systems. In detail one system based on two surface elevations, one system based on a surface elevation and a horisontal velocity and one system based...... tests with a highly reflective structure with the purely wave gauge based system and the wave gauge velocity meter based system are performed. The wave test depict the differences between the systems....

  9. An air-conditioning, ventilation and automatic ventilation monitoring and recording system constructed in an unsealed radioisotope laboratory. Energy-saving measures in Nagasaki University Radioisotope Center

    International Nuclear Information System (INIS)

    Takatsuji, Toshihiro; Yoshida, Masahiro; Takao, Hideaki; Okumura, Yutaka; Ooura, Tosinobu; Kotoura, Kazuki; Yamanaka, Yasushi; Yanagita, Hiroyoshi.

    1998-01-01

    We constructed an automatic operation system of air-conditioners and ventilators in a radiation controlled area to minimize electric consumption. The system operates the air-conditioner and the ventilator of each ventilation unit when someone is staying in rooms belonging to the unit based on information from an access control system to the controlled area and lighting switches in front of individual room. For understanding of operation conditions and confirmation of radioactive concentration in air lower than the legal limit at the ventilation stack, we also constructed an automatic ventilation monitoring and recording system, which makes complete operation records of each ventilator automatically. These systems enabled to achieve sharp energy-saving compatible with radiation protection. (author)

  10. Cosmological Evolution of QSO Absorption Systems

    Science.gov (United States)

    Stengler-Larrea, Erik

    1995-08-01

    First, the evolution with cosmic time of the hydrogen clouds which produce the Lyman-alpha absorption lines is studied in dependence on the strength of these lines. From the analysis it is concluded that the results show no evidence of a dependence in the sense of stronger lines evolving faster, although for the resolution at which the used observations were done, it can not be ruled out. Within the same analysis, a distribution of the Doppler parameter of the lines was obtained, with large values and a wide spread. This parameter being an indicator of the gas temperature, this result is in accordance with high temperatures and, consequently, large ionised fractions and a large fraction of the baryonic matter of the universe being associated with these clouds. However, recent high resolution studies seem to reveal that much lower temperatures are characteristic of the clouds. The main content of this thesis, however, focuses on the redshift evolution of the absorbing systems producing absorption at the Lyman limit and of the amount of CIV producing CIV absorption lines. Regarding the CIV absorbers, previous predictions on the effects underlying their redshift distribution pointed to an increase with redshift of the absorbing column densities. In this thesis the first direct measurements of such column densities by profile fitting of a large number of absorption systems (73) are presented, confirming the predictions of a decrease of at least a factor of 3 between z=1.5 and z=3.0. The study on the evolution of Lyman limit absorption systems (LLSs) puts an end to previous discrepancies between the results of different groups. Both a smooth single power law dependence of the LLS number density on redshift indicating no evolution in number density for 0.4 Team of the HST Key Project on QSO absorption lines, and in particular to estimate the necessary exposure times, the magnitudes of several of these objects had to be re-measured. The acquisition of their images and the

  11. [Relationships between air conditioning, airborne microorganisms and health].

    Science.gov (United States)

    Parat, S; Perdrix, A; Baconnier, P

    1999-01-01

    Concurrently with the increase of air-conditioning, potentially severe or frequent new diseases have emerged, giving rise to social and economical consequences. The first part of this work is a state of the art review of the relationships between air-conditioning, airborne microorganisms and health, through a technical, metrological and medical approach. The second part presents four studies performed in this field. Two of them deal with the relationship between airborne microorganisms and technical features of air-conditioning. Measurements performed on actual sites demonstrated the benefit of using high efficiency filters and low risk components in air-conditioning systems. The third study was aimed to look for a relationship between airborne microorganisms and sick building syndrome symptoms. Statistical analyses of individual data revealed significant associations between airborne bacteria or fungi and symptoms. These results may be the first step in determining a dose-response relationship, in order to define threshold limit values in this field. In the fourth study, the contribution of particle counting in assessing exposure to airborne microorganisms was explored by monitoring simultaneous variations of microbial and particle concentrations. The results showed that associating particle counting may allow to detect microbial variations instantaneously, and therefore improve the assessment of exposure to airborne microorganisms.

  12. The characteristics of welded joints for air conditioning application

    Science.gov (United States)

    Weglowski, M. St.; Weglowska, A.; Miara, D.; Kwiecinski, K.; Błacha, S.; Dworak, J.; Rykala, J.; Pikula, J.; Ziobro, G.; Szafron, A.; Zimierska-Nowak, P.; Richert, M.; Noga, P.

    2017-10-01

    In the paper the results of metallographic examination of welded joints for air-conditioning elements are presented. The European directives 2006/40/EC on the greenhouse gasses elimination demand to stop using traditional refrigerant and to change it to R744 (CO2) medium in air conditioning installation. The R744 refrigerant is environmental friendly medium if compared with standard solution such as R12, R134a or R1234yf and safer for passengers than R1234yf. The non-standard thermodynamic parameters of the R744 which translate into high pressure and high temperature require specific materials to develop the shape and to specify the technology of manufacturing for the particular elements of the conduits and moreover the technologies of joining for the whole structure, which would meet the exploitation requirements of the new air-conditioning system. To produce the test welded joints of stainless steels four different joining technologies were applied: laser welding, plasma welding, electron beam welding as well as high speed rotation welding. This paper describes the influence of the selected welding process on the macrostructure and microstructure of welded joints of AISI 304 and AISI 316L steels. The results indicated that plasma welding laser welding and electron beam welding technologies guaranty the proper quality of welded joints and can be used for the air conditioning application in automotive industry. However, high speed rotation welding not guarantee the good quality of welded joints and cannot be used for above application.

  13. Air Conditioning and Refrigeration. Book One.

    Science.gov (United States)

    Wantiez, Gary W.

    Designed to provide students with the basic skills for an occupation in air conditioning and refrigeration, this curriculum guide includes seven major areas, each consisting of one or more units of instruction. These areas and their respective units are titled as follows: Orientation (history and development, and job opportunities), Safety…

  14. Air conditioning total system for a coffee house. Groundwater as a supplier for heat and coldness; Klimatechnisches Gesamtsystem fuer ein Cafe. Grundwasser als Waerme- und Kaelte-Lieferant

    Energy Technology Data Exchange (ETDEWEB)

    Platzer, Gerald [Daikin Airconditioning Germany GmbH, Stutensee (Germany)

    2010-07-01

    The new building of a coffee-house of the land baker's shop Ihle on the outskirts of Augsburg (Federal Republic of Germany) was not only a new way of the baker's shop in the catering trade, but also in the conception of the building and its technical equipment. The linkage of heating, climate, ventilation and commercial refrigeration systems to a highly efficient total system succeeded in outstanding way.

  15. Refrigeration and air-conditioning technology workshop

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, P. J.; Counce, D. M. [eds.

    1993-01-01

    The Alternative Fluorocarbon Environmental Acceptability Study (AFEAS), a consortium of fluorocarbon manufacturers, and the US Department of Energy (DOE) are collaborating on a project to evaluate the energy use and global warming impacts of CFC alternatives. The goal of this project is to identify technologies that could replace the use of CFCs in refrigeration, heating, and air-conditioning equipment; to evaluate the direct impacts of chemical emissions on global warming; and to compile accurate estimates of energy use and, indirect CO{sub 2} emissions of substitute technologies. The first phase of this work focused on alternatives that could be commercialized before the year 2000. The second phase of the project is examining not-in-kind and next-generation technologies that could be developed to replace CFCs, HCFCs, and HFCs over a longer period. As part of this effort, Oak Ridge National Laboratory held a workshop on June 23--25, 1993. The preliminary agenda covered a broad range of alternative technologies and at least one speaker was invited to make a brief presentation at the workshop on each technology. Some of the invited speakers were unable to participate, and in a few cases other experts could not be identified. As a result, those technologies were not represented at the workshop. Each speaker was asked to prepare a five to seven page paper addressing six key issues concerning the technology he/she is developing. These points are listed in the sidebar. Each expert also spoke for 20 to 25 minutes at the workshop and answered questions from the other participants concerning the presentation and area of expertise. The primary goal of the presentations and discussions was to identify the developmental state of the technology and to obtain comparable data on system efficiencies. Individual papers are indexed separately.

  16. Endovascular vein harvest: systemic carbon dioxide absorption.

    Science.gov (United States)

    Maslow, Andrew M; Schwartz, Carl S; Bert, Arthur; Hurlburt, Peter; Gough, Jeffrey; Stearns, Gary; Singh, Arun K

    2006-06-01

    Endovascular vein harvest (EDVH) requires CO(2) insufflation to expand the subcutaneous space, allowing visualization and dissection of the saphenous vein. The purpose of this study was to assess the extent of CO(2) absorption during EDVH. Prospective observational study. Single tertiary care hospital. Sixty patients (30 EDVH and 30 open-vein harvest) undergoing isolated coronary artery bypass graft surgery. Hemodynamic, procedural, and laboratory data were collected prior to (baseline), during, and at it the conclusion (final) of vein harvesting. Data were also collected during cardiopulmonary bypass (CPB). Data were compared by using t tests, analysis of variance, and correlation statistics when needed. There were significant increases in arterial CO(2) (PaCO(2), 35%) and decreases in pH (1.35%) during EDVH. These were associated with increases in heart rate, mean blood pressure, and cardiac output. Within the EDVH group, greater elevations (>10 mmHg) in PaCO2 were more likely during difficult harvest procedures, and these patients exhibited greater increase in heart rate. Elevated CO(2) persisted during CPB, requiring higher systemic gas flows and greater use of phenylephrine to maintain desired hemodynamics. EDVH was associated with systemic absorption of CO(2). Greater absorption was more likely in difficult procedures and was associated with greater hemodynamic changes requiring medical therapy.

  17. FY1999 Meeting of The Society of Heating, Air-Conditioning and Sanitary Engineering of Japan. Hot water supply system; 1999 nendo gakujutsu koenkai gaiyo. Kyuto

    Energy Technology Data Exchange (ETDEWEB)

    Oze, H. [Toyo University, Tokyo (Japan)

    1999-12-05

    G-5 and 6 measure and investigate actual state of use of hot water supply systems in dormitories used by persons living alone without their families and by unmarried persons to collect fundamental data. G-5 considers how hot water is used, by making a questionnaire survey on the subject houses, and identifies the consumption trend of heat, water and hot water in the hot water supply systems as a whole. G-6 selected eleven houses from among the houses discussed in the previous report to identify the trend of use of hot water by each house. Also, quantity of hot water used in every day of the week is estimated. G-7 discusses methods for estimating water temperatures at faucets of water pipes from the water sources. This is intended to raise the accuracy of tap water temperature conversion coefficient by districts used for calculating estimated heat quantity as a parameter 'hot water supply energy consumption coefficient' to evaluate energy saving performance of a hot water supply facility. G-8 performs numerical simulations changing different parameters in the hot water supply piping system by using a heat loss calculation model for the existing household hot water supply piping. It executes evaluation on energy conservation performance of each model. G-9 estimates efficiency of instantaneous household gas hot water supply devices, not only on thermal efficiency of devices during steady state combustion, but also on non-steady state such as start-up, and discusses methods to derive actual efficiency by using calculations. (translated by NEDO)

  18. Alternative air-conditioning with the use of solar energy

    International Nuclear Information System (INIS)

    Algarbi, N. M.

    2006-01-01

    The paper concerns the investigation of the alternative air condition systems on the basis of the open absorbtion cycle with the use of solar energy as a heat source. Schematic solution of systems has been carried. The design analysis of working characteristics was performed for a wide rang of initial parameters (teperature and humidity of ambient air, the type and concentration of liquid sorbents, etc.) and construction features of heat and mass transfer.(Author)

  19. Thermodynamic performance analysis of gas-fired air-cooled adiabatic absorption refrigeration systems

    International Nuclear Information System (INIS)

    Wang, L.; Chen, G.M.; Wang, Q.; Zhong, M.

    2007-01-01

    In China, the application of small size gas-fired air-cooled absorption refrigeration systems as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand in Chinese big cities and lack of water resources. However, for conventional air-cooled absorption refrigeration systems, it is difficult to enhance the heat and mass transfer process in the falling film absorber, and may cause problems, for example, remarkable increase of pressure, temperature and concentration in the generators, risk of crystallization, acceleration of corrosion, degradation of performance, and so on. This paper presents a gas-fired air-cooled adiabatic absorption refrigeration system using lithium bromide-water solutions as its working fluid, which is designed with a cooling capacity of 16 kW under standard conditions. The system has two new features of waste heat recovery of condensed water from generator and an adiabatic absorber with an air cooler. Performance simulation and characteristic analysis are crucial for the optimal control and reliability of operation in extremely hot climates. A methodology is presented to simulate thermodynamic performance of the system. The influences of outdoor air temperature on operation performances of the system are investigated

  20. Experimental analysis and regression prediction of desiccant wheel behavior in high temperature heat pump and desiccant wheel air-conditioning system

    DEFF Research Database (Denmark)

    Sheng, Ying; Zhang, Yufeng; Sun, Yuexia

    2014-01-01

    The objectives of this study are to evaluate the performance of desiccant wheel (DW) in the running system and obtain the useful data for practical application. The combined influences of multiple variables on the performance of desiccant wheel are investigated based on evaluating the indexes...... of moisture removal capacity, dehumidification effectiveness, dehumidification coefficient of performance and sensible energy ratio. The results show that higher effect on the dehumidification is due to the regeneration temperature and outdoor air humidity ratio rather than the outdoor air temperature...... and the ratio between regeneration and process air flow rates. A simple method based on multiple linear regression theory for predicting the performance of the wheel has been proposed. The predicted values and the experimental data are compared and good agreements are obtained. Regression models are established...

  1. Proposal for the award of a contract for the design, supply, installation and commissioning of a ventilation and air conditioning system for the ECN3 experimental area and the TCC8 and GHN300 service tunnels and for the dismantling of the existing system

    CERN Document Server

    2014-01-01

    Proposal for the award of a contract for the design, supply, installation and commissioning of a ventilation and air conditioning system for the ECN3 experimental area and the TCC8 and GHN300 service tunnels and for the dismantling of the existing system

  2. Central Air-Conditioning Plant (CAP) extension

    International Nuclear Information System (INIS)

    Shetty, P.S.; Kaul, S.K.; Mishra, H.

    2017-01-01

    Central Air-Conditioning Plant (CAP) and its associated chilled water network of BARC is one among the largest central plants in India for such application. The plant was planned in 1960s to cater to the air-conditioning and process water requirements of laboratories, workshops and buildings spread over a distance of 1.5 Km in three directions from CAP through underground network of chilled water pipelines. The plant was designed for a total capacity of 6600 TR. The present installed capacity of the plant is 7250 TR. The connected load at present is 9800 TR. After the XII plan capacity will be augmented to 7650 TR. The connected load is expected to cross 11,000 TR after the commissioning of new Engg. Halls 9, 10 and 11

  3. Current status of and problems in ice heat storage systems contributing to improving load rate. Proliferation of the ice heat storage type air conditioning system and roles of the Heat Pump and Heat Storage Center; Fukaritsu kaizen ni kokensuru kori chikunetsu system no genjo to kadai. Kori chikunetsushiki kucho system no fukyu to heat pump chikunetsu center no yakuwari

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, T.

    1998-02-01

    This paper introduces the roles played by the `Heat Pump and Heat Storage Center`. This foundation had been performing research and development and international information exchange in devices and equipment as the `Heat Pump Technology Development Center`. Development of heat storage type air conditioning systems as a measure for load leveling, and efforts of their proliferation and enlightenment were added to the business activities. As a result, the foundation`s name was changed to the present name. Its activities being planned and performed include: interest supplementing operation for installation of an air conditioning system of the heat pump system using storage of latent heat such as ice heat storage, holding seminars for promoting proliferation of the ice heat storage type air conditioning system, opening the home page, participation in exhibitions of various types, and preparation of different publicity tools. More specifically, carrying series advertisements in newspapers and magazines, holding nation-wide symposiums tying up with Japan Economic Press, publishing an organ newspaper targeted at both of experts and general people, and preparation of general pamphlets to introduce comprehensively the information about heat storage. 3 figs., 1 tab.

  4. Waste energy driven air conditioning system (WEDACS)

    NARCIS (Netherlands)

    Eichhorn, R.H.L.; Boot, M.D.; Luijten, C.C.M.

    2009-01-01

    In the port injected Spark Ignition (SI) engine, the single greatest part load efficiency reducing factor are energy losses over the throttle valve. The need for this throttle valve arises from the fact that engine power is controlled by the amount of air in the cylinders, since combustion occurs

  5. Modelling of air-conditioned and heated spaces

    Energy Technology Data Exchange (ETDEWEB)

    Moehl, U

    1987-01-01

    A space represents a complex system involving numerous components, manipulated variables and disturbances which need to be described if dynamic behaviour of space air is to be determined. A justifiable amount of simulation input is determined by the application of adjusted modelling of the individual components. The determination of natural air exchange in heated spaces and of space-air flow in air-conditioned space are a primary source of uncertainties. (orig.).

  6. Analysis of a solar powered absorption system

    International Nuclear Information System (INIS)

    Said, S.A.M.; El-Shaarawi, M.A.I.; Siddiqui, M.U.

    2015-01-01

    Highlights: • Conventional absorption system modified to increase COP. • Results indicated increase of 10% in COP due to dephlegmator heat recovery. • Results indicated increase of 8% in COP due to refrigerant storage unit. • Results indicated increase of 18% in COP due to combined effect of modifications. • Simulation results indicated a very good agreement with the measured results. - Abstract: Today, fossil fuel is the primary extensively used source of energy. However, its negative impact on the environment have forced the energy research continuity to seriously consider renewable sources of energy. Solar energy, in particular, has been the main focus in this regard because it is a source of clean energy and naturally available. This study presents the design and analysis of a solar powered absorption refrigeration system modified to increase its coefficient of performance (COP). The modifications include recovering of waste heat from a dephlegmator and utilization of a refrigerant storage unit. The simulation results indicate an increase of 10% in the COP of the conventional design using dephlegmator heat recovery and an increase of 8% in the COP of the conventional design due to the use of a refrigerant storage. The analysis for the combined effect of modifications indicates an increase of 18% in the COP compared to conventional design. Calculated values of coefficient of performance indicate a very good agreement with the ones obtained based on measurement

  7. The Effect of Air-Conditioning on Student and Teacher Performance.

    Science.gov (United States)

    Phoenix Union High School District, AZ. Dept. of Research and Planning.

    The literature is reviewed to see if research shows a relationship between student and teacher performance and air conditioning of classrooms. The benefits of air conditioning in promoting learning are substantiated by studies that are summarized but not cited. The relationship of the report to the Phoenix Union High School System Advisory…

  8. Opportunities to Reduce Air-Conditioning Loads Through Lower Cabin Soak Temperatures

    International Nuclear Information System (INIS)

    Farrington, R.; Cuddy, M.; Keyser, M.; Rugh, J.

    1999-01-01

    Air-conditioning loads can significantly reduce electric vehicle (EV) range and hybrid electric vehicle (HEV) fuel economy. In addition, a new U. S. emissions procedure, called the Supplemental Federal Test Procedure (SFTP), has provided the motivation for reducing the size of vehicle air-conditioning systems in the United States. The SFTP will measure tailpipe emissions with the air-conditioning system operating. If the size of the air-conditioning system is reduced, the cabin soak temperature must also be reduced, with no penalty in terms of passenger thermal comfort. This paper presents the impact of air-conditioning on EV range and HEV fuel economy, and compares the effectiveness of advanced glazing and cabin ventilation. Experimental and modeled results are presented

  9. The importance of the ammonia purification process in ammonia-water absorption systems

    International Nuclear Information System (INIS)

    Fernandez-Seara, Jose; Sieres, Jaime

    2006-01-01

    Practical experience in working with ammonia-water absorption systems shows that the ammonia purification process is a crucial issue in order to obtain an efficient and reliable system. In this paper, the detrimental effects of the residual water content in the vapour refrigerant are described and quantified based on the system design variables that determine the effectiveness of the purification process. The study has been performed considering a single stage system with a distillation column with complete condensation. The ammonia purification effectiveness of the column is analysed in terms of the efficiencies in the stripping and rectifying sections and the reflux ratio. By varying the efficiencies from 0 to 1, systems with neither the rectifying nor stripping section, with either the rectifying or stripping section, or with both sections can be considered. The impact of the ammonia purification process on the absorption system performance is studied based on the column efficiencies and reflux ratio; and its effects on refrigerant concentration, system COP, system pressures and main system mass flow rates and concentrations are analysed. When the highest efficiency rectifying sections are used a combination of generation temperature and reflux ratio which leads to optimum COP values is found. The analysis covers different operating conditions with air and water cooled systems from refrigeration to air conditioning applications by changing the evaporation temperature. The importance of rectification in each kind of application is evaluated

  10. 2017 German refrigeration and air conditioning meeting. Proceedings

    International Nuclear Information System (INIS)

    2017-01-01

    This year's lecture programme includes 117 presentations in the five working departments of DKV and 10 lectures at the special event ''Energy-efficient air conditioning in data centres''. The main topics in the respective departments were: (1) Cryogenics: Space applications; Cryogenic plants; Cryomedicine and cryobiology; Components, developments; Processes and plants; Valves, design. (2) Basics: Evaporation, material values; evaporation, condensation; absorption; adsorption, latent storage; cycle simulation. (3) Components: CO 2 plant engineering and components; refrigerants; process control, adsorption, sublimation and storage technology; refrigerating machine oils, heat exchangers and corrosion; components 4.0, sensors and control technology; simulation of plant processes. (4) Cold application: Application; Application / Natural Refrigerants; Mobile Applications Car; Mobile Applications; Supermarket / Efficiency; Optimization / Efficiency. (5) Air conditioning and heat pump applications: load shifting, smart home, flexibility; heat sources and industrial heat pumps; modelling, simulations; energy concepts heat pumps and photovoltaics; monitoring, evaluation; technology trends / working materials. Six papers are separately analyzed for this database. [de

  11. Optimization in selection of the filter for central air conditioning system in public buildings%公共建筑集中空调系统过滤器选型方法优化

    Institute of Scientific and Technical Information of China (English)

    司鹏飞; 樊越胜; 李安桂; 谢伟; 龚锐; 戎向阳

    2011-01-01

    To meet the requirements of the average mass concentration of PM10 in indoor air and supply air, establishes a mathematical model for filter selection of the primary return air conditioning system according to the mass conservation law. In order to facilitate HVAC designing, simplifies the mathematical model, and gives the determination method of PM10 mass concentration in outdoor air and calculation methods of indoor dust production.%为了满足集中空调建筑室内PM10平均质量浓度以及送风气流中PM10的质量浓度要求,利用质量守恒定律建立了一次回风空调系统过滤器选型数学模型.为了便于暖通设计人员进行选型计算,对所建立的数学模型进行了合理的简化,并给出了室外PM10质量浓度的确定方法以及室内发尘量的计算方法.

  12. Proceedings of the 1993 non-fluorocarbon insulation, refrigeration and air conditioning technology workshop

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  13. History of ventilation and of air conditioning in Dolni Rozinka uranium mines

    International Nuclear Information System (INIS)

    Voltr, S.

    1987-01-01

    At a time of the start of mining operations in the Dolni Rozinka uranium mine, ventilation had been provided using the underpressure technique with diagonal winding shafts. From 1967 the overpressure system had been used. The system is described in detail and its constraints are listed. In 1983, on the basis of an analysis and model tests, the ventilation system was replaced by a underpressure system which satisfied the current hygiene specifications, was costsaving and reliable. Since 1985, an air conditioning system has been in operation featuring mobile cooling units and a closed-circuit air conditioning water system that is separated from the mining water pumping system. In view of the favourable temperature factors of the deposit, the mobile air conditioning units are only installed in blind headings. When the through-flow wind stream is achieved, air conditioning is abandoned. (J.B.). 2 figs., 5 refs

  14. Aspects on modeled and the design of a system of refrigeration by absorption attended with solar energy; Aspectos sobre el modelado y diseno de un sistema de refrigeracion por absorcion asistido con energia solar

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Cascales, J. R.; Vera Garcia, F.; Cano Izquierdo, J. M.; Delgado Marin, J. P.; Martinez Sanchez, R.

    2008-07-01

    In this paper, we study the global modelling of an absorption system working with Br Li-H{sub 2}O. It satisfies the air-conditioning necessities of a classroom in an educational centre in Puerto Lumbreras. Murcia. This system utilises a set of solar collector to satisfy the thermal necessities of the vapour generator in the absorption system. For the dynamical simulation of the system we have used the TRNSYS software. The air-conditioned place has been modelled by using a TRNSYS module called PREBID. In this work, special attention is paid to the absorption equipment model developed by using neural networks which has been implemented in TRNSYS. The paper is closed drawing some conclusions. (Author)

  15. Magnetic Refrigeration Technology for High Efficiency Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Boeder, A; Zimm, C

    2006-09-30

    Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate

  16. On-road performance analysis of R134a/R600a/R290 refrigerant mixture in an automobile air-conditioning system with mineral oil as lubricant

    International Nuclear Information System (INIS)

    Ravikumar, T.S.; Mohan Lal, D.

    2009-01-01

    R134a has been accepted as the single major refrigerant in the automobile industry and it has been used worldwide. But, the problem associated with it is the use of the PAG oil as the lubricant. Unlike the conventional mineral oil, the synthetic PAG oil used with R134a is highly hygroscopic in nature. The PAG lubricants come with different additives unique for different compressors. This leads to serious service issues. Therefore, a refrigerant, which will be readily available to replace R12, and also compatible with mineral oil, is needed. In the present study the readily available R134a is used in place of R12. However, to avoid PAG oil and to use the conventional mineral oil as lubricant, R134a is mixed with the commercially available hydrocarbon blend, (45.2% R290 and 56.8% R600a) in the proportion of 91% and 9%, respectively by mass. The quantity of hydrocarbons used is well below the lower flammable limit. This new mixture R134a/R600a/R290 is tested in the air-conditioning system of a passenger car 'on road' in the true running conditions and compared with the results that has been obtained with R12. The cool down performance under varying speed and varying ambient conditions, system performance under severe accelerating conditions and bumper-to-bumper traffic conditions is studied. The test results show that the new blend can be a promising substitute for the existing R12 systems and it can eliminate the use of hygroscopic PAG oil.

  17. FY 1977 Annual report on Sunshine Project results. Research and development of solar energy systems for air conditioning and hot water supply (Research and development of solar systems for condominiums); 1977 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Shugo jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-06-01

    This project is aimed at technological development of economical solar energy systems for air conditioning and hot water supply for condominiums. The major items for the FY 1977 programs include (1) designs and fabrication of equipment for a test building, (2) development of the equipment materials, and (3) system analysis. The jobs for item (1) include management of the designs and construction, placing an order for the building, and fabrication of an air conditioner expander and heat pump; those for item (2) include simplification of a condensing type and plate type heat collector structures, weather-resistance of the plate type heat collector structure, and materials for selective absorbing membranes and reflectors; and those for item (3) include estimation of heat loads in a model building, first to third floors as the test building, and fourth to 14th floors as the conventional box-shaped building. The heat collector installation area is investigated for a multistory building, for which solar radiation intensity at the heat-receiving plane and the like are taken into account. It is found that the solar system can be installed, when an area of 50m{sup 2} can be allocated to the system in each story. There is a limit to story number for the solar system to economically work for air conditioning and hot water supply. Sufficient insulation of the system and reduction in pipe length by zoning are the necessary measures against heat losses. (NEDO)

  18. Gintonin absorption in intestinal model systems

    Directory of Open Access Journals (Sweden)

    Byung-Hwan Lee

    2018-01-01

    Conclusion: The present study shows that gintonin could be absorbed in the intestine through transcellular and paracellular diffusion, and active transport. In addition, the lipid component of gintonin might play a key role in its intestinal absorption.

  19. Cloud Absorption Radiometer Autonomous Navigation System - CANS

    Science.gov (United States)

    Kahle, Duncan; Gatebe, Charles; McCune, Bill; Hellwig, Dustan

    2013-01-01

    CAR (cloud absorption radiometer) acquires spatial reference data from host aircraft navigation systems. This poses various problems during CAR data reduction, including navigation data format, accuracy of position data, accuracy of airframe inertial data, and navigation data rate. Incorporating its own navigation system, which included GPS (Global Positioning System), roll axis inertia and rates, and three axis acceleration, CANS expedites data reduction and increases the accuracy of the CAR end data product. CANS provides a self-contained navigation system for the CAR, using inertial reference and GPS positional information. The intent of the software application was to correct the sensor with respect to aircraft roll in real time based upon inputs from a precision navigation sensor. In addition, the navigation information (including GPS position), attitude data, and sensor position details are all streamed to a remote system for recording and later analysis. CANS comprises a commercially available inertial navigation system with integral GPS capability (Attitude Heading Reference System AHRS) integrated into the CAR support structure and data system. The unit is attached to the bottom of the tripod support structure. The related GPS antenna is located on the P-3 radome immediately above the CAR. The AHRS unit provides a RS-232 data stream containing global position and inertial attitude and velocity data to the CAR, which is recorded concurrently with the CAR data. This independence from aircraft navigation input provides for position and inertial state data that accounts for very small changes in aircraft attitude and position, sensed at the CAR location as opposed to aircraft state sensors typically installed close to the aircraft center of gravity. More accurate positional data enables quicker CAR data reduction with better resolution. The CANS software operates in two modes: initialization/calibration and operational. In the initialization/calibration mode

  20. Reducing a solar-assisted air-conditioning system’s energy consumption by applying real-time occupancy sensors and chilled water storage tanks throughout the summer: A case study

    International Nuclear Information System (INIS)

    Rosiek, S.; Batlles, F.J.

    2013-01-01

    Highlights: • We present an innovative occupancy and chilled water storage-based operation mode. • This mode was implemented to the solar-assisted air-conditioning system. • It permits to save 42% of total electrical energy during one cooling period. • It allows storing the excess cooling capacity of the absorption chiller. • It prevents the sudden start/stop (on/off cycles) of the absorption chiller. - Abstract: This study describes an innovative occupancy and chilled-water storage-based operation sequence implemented in a solar-assisted air-conditioning system. The core purpose of this solar-assisted air-conditioning system is to handle the cooling and heating load of the Solar Energy Research Centre (CIESOL), thus minimising its environmental impact. In this study, the cooling mode was investigated with special attention focused on the chilled-water storage circuit. The critical concern is that the solar-assisted air-conditioning system should always operate considering the actual load conditions, not using an abstract maximum load that is predetermined during the system’s design process, which can lead to energy waste during periods of low occupancy. Thus, the fundamental problem is to identify the optimum operation sequence for the solar-assisted air-conditioning system that provides the best energy performance. The significance of this work lies in the demonstration of a new operation strategy that utilises real-time occupancy monitoring and chilled-water storage tanks to improve the efficiency of solar-assisted air-conditioning systems, thereby reducing their electricity consumption. Adopting this strategy resulted in a large energy-saving potential. The results demonstrate that during one cooling period, it is possible to conserve approximately 42% of the total electrical energy consumed by the system prior to the adoption of this operation strategy

  1. Air conditioning device for reactor buildings

    International Nuclear Information System (INIS)

    Kikuchi, Shiro.

    1982-01-01

    Purpose: To decrease the opening areas of pipe lines for an air conditioning device at the portions passing through the shielding walls of a reactor building for a FBR type reactor, as well as reduce the size of the building. Constitution: Airs in the building for containing reactor are liquefied in an air liquefying mechanism. The liquefied airs are sent by way of pipe lines to each of evaporators, wherein each of the chambers are cooled because of latent heat of evaporation and evaporated airs are released to each of the chambers. The airs released to each of the chambers are collected into an exhaust chamber and sent by way of a duct to the air liquefying mechanism and liquefied again. Since the volume of the liquefied airs may be smaller than the amount conventionally required for usual cooled airs, the pipe lines passing through the shielding walls of the building can be of smaller diameter. This can decrease the opening areas of the pipe lines at the portions passing through the walls of the shieldings and, since the opening areas are smaller, the structure of the radiation shieldings can be simplified in these portions. Further, since the space of the pipe lines in the building is reduced extremely, the size of the building can be reduced. (Moriyama, K.)

  2. Smart Sensors Enable Smart Air Conditioning Control

    Directory of Open Access Journals (Sweden)

    Chin-Chi Cheng

    2014-06-01

    Full Text Available In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants’ information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans’ intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It’s also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection.

  3. Experimental investigation of integrated refrigeration system (IRS) with gas engine, compression chiller and absorption chiller

    International Nuclear Information System (INIS)

    Sun, Z.G.

    2008-01-01

    An integrated refrigeration system (IRS) with a gas engine, a vapor-compression chiller and an absorption chiller is set up and tested. The vapor-compression refrigeration cycle is operated directly by the gas engine. The waste heat from the gas engine operates the absorption refrigeration cycle, which provides additional cooling. The performance of the IRS is described. The cooling capacity of the IRS is about 596 kW, and primary energy ratio (PER) reaches 1.84 at air-conditioning rated conditions. The refrigerating capacity of the prototype increased and PER of prototype decreased with the increase of the gas engine speed. The gas engine speed was preferably regulated at part load condition in order to operate the prototype at high-energy efficiency. The refrigerating capacity and PER of the prototype increased with the increase of the outlet temperature of chilled water or the decrease of the inlet temperature of cooling water. The integrated refrigeration chiller in this work saves running costs as compared to the conventional refrigeration system by using the waste heat

  4. Application of the exergetic cost theory to the LiBr/H2O vapour absorption system

    International Nuclear Information System (INIS)

    Misra, R.D.; Sahoo, P.K.; Gupta, A.

    2002-01-01

    Optimization of thermal systems is generally based on thermodynamic analysis. However, the systems so optimized often are not viable due to economic constraints. The Theory of Exergetic Cost, a thermoeconomic optimization technique, combines the thermodynamic analysis with that of economic constraints to obtain an optimum configuration of a thermal system. In this paper, this technique is applied to optimize a LiBr/H 2 O vapour absorption refrigeration system run by pressurized hot water for air-conditioning applications. The mathematical and numerical techniques-based optimization of thermal systems is not always possible due to plant complexities. Hence, a simplified cost minimization methodology, based on 'Theory of Exergetic Cost', is applied to evaluate the economic costs of all the internal flows and products of the system under consideration. As shown in this paper, once these costs are determined, an approximately optimum design configuration can be obtained

  5. Model systems for understanding absorption tuning by opsin proteins

    DEFF Research Database (Denmark)

    Nielsen, Mogens Brøndsted

    2009-01-01

    This tutorial review reports on model systems that have been synthesised and investigated for elucidating how opsin proteins tune the absorption of the protonated retinal Schiff base chromophore. In particular, the importance of the counteranion is highlighted. In addition, the review advocates...... is avoided, and it becomes clear that opsin proteins induce blueshifts in the chromophore absorption rather than redshifts....

  6. Experimental analysis of a diffusion absorption refrigeration system used alternative energy sources

    International Nuclear Information System (INIS)

    Soezen, A.; Oezbas, E.

    2009-01-01

    The continuous-cycle absorption refrigeration device is widely used in domestic refrigerators, and recreational vehicles. It is also used in year-around air conditioning of both homes and larger buildings. The unit consists of four main parts the boiler, condenser, evaporator and the absorber. When the unit operates on kerosene or gas, the heat is supplied by a burner. This element is fitted underneath the central tube. When operating on electricity, the heat is supplied by an element inserted in the pocket. No moving parts are employed. The operation of the refrigerating mechanism is based on Dalton's law. In this study, experimental analysis was performed of a diffusion absorption refrigeration system (DARS) used alternative energy sources such as solar, liquid petroleum gas (LPG) sources. Two basic DAR cycles were set up and investigated: i) In the first cycle (DARS-1), the condensate is sub-cooled prior to the evaporator entrance by the coupled evaporator/gas heat exchanger similar with manufactured by Electrolux Sweden. ii) In the second cycle (DARS-2), the condensate is not sub-cooled prior to the evaporator entrance and gas heat exchanger is separated from the evaporator. (author)

  7. Flow and air conditioning simulations of computer turbinectomized nose models.

    Science.gov (United States)

    Pérez-Mota, J; Solorio-Ordaz, F; Cervantes-de Gortari, J

    2018-04-16

    Air conditioning for the human respiratory system is the most important function of the nose. When obstruction occurs in the nasal airway, turbinectomy is used to correct such pathology. However, mucosal atrophy may occur sometime after this surgery when it is overdone. There is not enough information about long-term recovery of nasal air conditioning performance after partial or total surgery. The purpose of this research was to assess if, based on the flow and temperature/humidity characteristics of the air intake to the choana, partial resection of turbinates is better than total resection. A normal nasal cavity geometry was digitized from tomographic scans and a model was printed in 3D. Dynamic (sinusoidal) laboratory tests and computer simulations of airflow were conducted with full agreement between numerical and experimental results. Computational adaptations were subsequently performed to represent six turbinectomy variations and a swollen nasal cavity case. Streamlines along the nasal cavity and temperature and humidity distributions at the choana indicated that the middle turbinate partial resection is the best alternative. These findings may facilitate the diagnosis of nasal obstruction and can be useful both to plan a turbinectomy and to reduce postoperative discomfort. Graphical Abstract ᅟ.

  8. Measurement of Vehicle Air Conditioning Pull-Down Period

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, John F [ORNL; Huff, Shean P [ORNL; Moore, Larry G [ORNL; West, Brian H [ORNL

    2016-08-01

    Air conditioner usage was characterized for high heat-load summer conditions during short driving trips using a 2009 Ford Explorer and a 2009 Toyota Corolla. Vehicles were parked in the sun with windows closed to allow the cabin to become hot. Experiments were conducted by entering the instrumented vehicles in this heated condition and driving on-road with the windows up and the air conditioning set to maximum cooling, maximum fan speed and the air flow setting to recirculate cabin air rather than pull in outside humid air. The main purpose was to determine the length of time the air conditioner system would remain at or very near maximum cooling power under these severe-duty conditions. Because of the variable and somewhat uncontrolled nature of the experiments, they serve only to show that for short vehicle trips, air conditioning can remain near or at full cooling capacity for 10-minutes or significantly longer and the cabin may be uncomfortably warm during much of this time.

  9. The Role of Absorption Cooling for Reaching Sustainable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lindmark, Susanne

    2005-07-01

    This thesis focuses on the role and potential of absorption cooling in future energy systems. Two types of energy systems are investigated: a district energy system based on waste incineration and a distributed energy system with natural gas as fuel. In both cases, low temperature waste heat is used as driving energy for the absorption cooling. The main focus is to evaluate the absorption technology in an environmental perspective, in terms of reduced CO{sub 2} emissions. Economic evaluations are also performed. The reduced electricity when using absorption cooling instead of compression cooling is quantified and expressed as an increased net electrical yield. The results show that absorption cooling is an environmentally friendly way to produce cooling as it reduces the use of electrically driven cooling in the energy system and therefore also reduces global CO{sub 2} emissions. In the small-scale trigeneration system the electricity use is lowered with 84 % as compared to cooling production with compression chillers only. The CO{sub 2} emissions can be lowered to 45 CO{sub 2}/MWh{sub c} by using recoverable waste heat as driving heat for absorption chillers. However, the most cost effective cooling solution in a district energy system is a combination between absorption and compression cooling technologies according to the study. Absorption chillers have the potential to be suitable bottoming cycles for power production in distributed systems. Net electrical yields over 55 % may be reached in some cases with gas motors and absorption chillers. This small-scale system for cogeneration of power and cooling shows electrical efficiencies comparable to large-scale power plants and may contribute to reducing peak electricity demand associated with the cooling demand.

  10. Substitution of the old console with a fully computerized one. Major maintenance and enhancements of the ventilation and air conditioning system of the reactor building. Research activities at the TRIGA L.E.N.A. plant in Pavia, Italy

    International Nuclear Information System (INIS)

    Orvini, E.; Piazzoli, A.; Borio, A.

    2008-01-01

    The TRIGA Mark II reactor of the University of Pavia was operated in the last two years on a routine basis accomplishing different purposes: - Development of B.N.C.T. for diffused tumours of liver; - Neutron activation analysis in matrix of geochemistry, archaeology and environment interest; - Electron spin resonance (ESR) study of radical processes; - Study of trace elements impact in environmental matrix and human health; - High purity control on electronic samples-microchips; - Fast neutron radiation damage investigation; - Certification of standard reference materials and data quality assurance by neutron activation analysis; - Age evaluation by Ar-K method in geological matrix; - Trace elements determination for provenience studies in archaeology; - Basic experiments on fission of Am-242 layers for the space nuclear engine project; - In field search of explosive using prompt gamma emission induced by neutron capture on nitrates. In the period of time between July 1998 and June 2000 the reactor was operated at full power (i.e. 250 kW) for a total amount of 1375 hours. The total fuel element burn-up was 15.07 MWD. During this period of time two major upgrading activities were planned: the installation of a new Instrumentation and Control System (ICS) for the reactor and the installation of a new Air Conditioning and Filtering System (ACFS) for the reactor building. The new ICS is a microprocessor-based design, incorporating the use of one logarithmic wide range neutron flux monitoring channel (NLW-1000), two current mode neutron monitoring safety channels (NP-1000 and NPP-1000) and a linear multi-range neutron flux monitoring channel (Keithley 485). The ICS configuration was personalized by General Atomic according to the requirements and to the technical prescriptions of the Pavia reactor, especially for what concerns the SCRAM inputs and the detectors architecture. Besides, since one the two safety channels, the NPP-1000, has been developed as an advanced

  11. The low-ion QSO absorption-line systems

    International Nuclear Information System (INIS)

    Lanzetta, K.M.

    1988-01-01

    Various techniques are used to investigate the class of QSO absorption-line systems that exhibit low-ion absorption lines. Four separate investigations are conducted as follows: Spectroscopy of 32 QSOs at red wavelengths is presented and used to investigate intermediate-redshift MgII absorption. A total of 22 Mg II doublets are detected, from which properties of the Mg II absorbers are derived. Marginal evidence for intrinsic evolution of the number density of the Mg II absorbers with redshift is found. The data are combined with previous observations of C IV and C II seen in the same QSOs at blue wavelengths, and the properties of Mg II- and C IV-selected systems are compared. A sample is constructed of 129 QSOs for which are available published data suitable for detecting absorption-line systems that are optically thick to Lyman continuum radiation. A total of 53 such Lyman-limit systems are found, from which properties of the Lyman-limit systems are derived. It is found that the rate of incidence of the systems does not strongly evolved with redshift. This result is contrasted with the evolution found previously for systems selected on the basis of Mg II absorption. Spectroscopy at red wavelengths of eight QSOs with known damped Lyα absorption systems is presented. Spectroscopic and spectrophotometric observations aimed at detecting molecular hydrogen and dust in the z = 2.796 damped Lyα absorber toward Q1337 + 113 are presented

  12. Experimental investigation on an ammonia-water-lithium bromide absorption refrigeration system without solution pump

    International Nuclear Information System (INIS)

    Wu Tiehui; Wu Yuyuan; Yu Zhiqiang; Zhao Haichen; Wu Honglin

    2011-01-01

    Highlights: → An absorption refrigeration system with ternary solution of NH 3 -H 2 O-LiBr was set up. → Performance of the NH 3 -H 2 O-LiBr system without solution pump was firstly tested. → Generator pressure in NH 3 -H 2 O-LiBr system was lower than the one in NH 3 -H 2 O system. → The COP of the NH 3 -H 2 O-LiBr system was 51.89% larger than the NH 3 -H 2 O binary system. → The optimum mass fraction of LiBr of about 23% led to the largest COP of 0.401. -- Abstract: Experimental researches were carried out on a novel ammonia-water-lithium bromide ternary solution absorption refrigeration and air-conditioning system without solution pump and distillation equipments. The experiments were conducted by using three kinds of NH 3 -H 2 O binary solution and 17 kinds of ternary solution with difference in mass fraction of NH 3 and LiBr. The experimental results showed that the vapor pressure of the generator in the system would be lower than that of the generator in an ammonia-water absorption system. In above two situations the same ammonia mass fraction and the same solution temperature were kept. The amplitude of vapor pressure decrease of the system generator would be larger with the increase of the mass fraction of LiBr. The maximum amplitude of decrease would be of 50%. With the increase of the mass fraction of LiBr, the coefficient of performance (COP) of the system would be increased initially, and then decreased later when the mass fraction of LiBr exceeded a certain value. This value was about 23% for the solution with ammonia mass fraction of 50% and 55%, and about 30% for the solution with ammonia mass fraction of 60%. Compared with the ammonia-water system, the COP of the ternary solution system with the same mass fraction of ammonia would increase up to 30%. With the ammonia mass fraction of 60% and LiBr mass fraction of 30% applied, the COP of the ternary solution system was increased up to 0.401. It was 51.89% higher than that when binary

  13. Artificial neural network analysis of triple effect absorption refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Hajizadeh Aghdam, A. [Department of Mechanical Engineering, Islamic Azad University (Iran, Islamic Republic of)], email: a.hajizadeh@iaukashan.ac.ir; Nazmara, H.; Farzaneh, B. [Department of Mechanical Engineering, University of Tabriz (Iran, Islamic Republic of)], email: h.nazmara@nioec.org, email: b_farzaneh_ms@yahoo.com

    2011-07-01

    In this study, artificial neural networks are utilized to predict the performance of triple effect series and parallel flow absorption refrigeration systems, with lithium bromide/water as the working fluid. Important parameters such as high generator and evaporator temperatures were varied and their effects on the performance characteristics of the refrigeration unit were observed. Absorption refrigeration systems make energy savings possible because they can use heat energy to produce cooling, in place of the electricity used for conventional vapour compression chillers. In addition, non-conventional sources of energy (such as solar, waste heat, and geothermal) can be utilized as their primary energy input. Moreover, absorption units use environmentally friendly working fluid pairs instead of CFCs and HCFCs, which affect the ozone layer. Triple effect absorption cycles were analysed. Results apply for both series and parallel flow systems. A relative preference for parallel-flow over series-flow is also shown.

  14. 8th International Symposium on Heating, Ventilation and Air Conditioning

    CERN Document Server

    Zhu, Yingxin; Li, Yuguo; Vol.1 Indoor and Outdoor Environment; Vol.2 HVAC&R Component and Energy System; Vol.3 Building Simulation and Information Management

    2014-01-01

    Proceedings of the 8th International Symposium on Heating, Ventilation and Air Conditioning is based on the 8th International Symposium of the same name (ISHVAC2013), which took place in Xi’an on October 19-21, 2013. The conference series was initiated at Tsinghua University in 1991 and has since become the premier international HVAC conference initiated in China, playing a significant part in the development of HVAC and indoor environmental research and industry around the world. This international conference provided an exclusive opportunity for policy-makers, designers, researchers, engineers and managers to share their experience. Considering the recent attention on building energy consumption and indoor environments, ISHVAC2013 provided a global platform for discussing recent research on and developments in different aspects of HVAC systems and components, with a focus on building energy consumption, energy efficiency and indoor environments. These categories span a broad range of topics, and the proce...

  15. The natural gas air-conditioning; La climatisation au gaz naturel. Un avenir prometteur, une technique confirmee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The natural gas air-conditioning market is in growth (it will cover 10% of the market in 2002).To illustrate the possibilities of this energy source, this paper presents three examples of the natural gas air-conditioning in France. The technical aspects, the cost and the advantages of such systems are discussed. (A.L.B.)

  16. The distribution of absorptive power dissipation in irradiated nanoparticulate system

    International Nuclear Information System (INIS)

    Li, Jiayu; Yang, Jian; Gu, Xiaobing

    2016-01-01

    The knowledge of local radiant absorption is important to the nanostructure optimization, it is beneficial to the applications in energy harvesting, optical heating, photocatalysis, etc. In this paper, FDTD model is constructed for the distribution of absorptive power dissipation in irradiated nanoparticulate system. The theoretical model extended from Mie theory is used to examine the FDTD model, the parameters and conditions set for FDTD simulation are confirmed based on the comparison. Then, the influence of Ag nanoparticle on the absorptive properties of nearby TiO_2 nanoparticle is investigated by FDTD simulation at the wavelength of 0.25 μm. It is indicated that suitable distance between TiO_2 and Ag particles is beneficial to the spectral radiant absorption of TiO_2 particle. Considering the agglomeration of nanoparticles and the oxidation at the TiO_2–Ag interface, the Ag core coated with Al_2O_3 shell is suggested, and the simulated results indicated that the shell thickness and the Ag core size need to be optimized for enhancing the radiant absorption of TiO_2 particle. - Highlights: • The absorptive power distribution in nanoparticulate system is simulated by FDTD. • FDTD simulation is compared with theoretical model extended from Mie theory. • The parameters and conditions are confirmed based on the comparison. • The influence of Ag nanoparticle on nearby TiO_2 particle's absorption is analyzed.

  17. Ab-sorption machines for heating and cooling in future energy systems - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tozer, R.; Gustafsson, M.

    2000-12-15

    After the Executive Summary and a brief introductory chapter, Chapter 2, Sorption Technologies for Heating and Cooling in Future Energy Systems, reviews the main types of sorption systems. Chapter 3, Market Segmentation, then considers the major segments of the market including residential, commercial/institutional and industrial, and the types of sorption hardware most suitable to each. The highly important residential and commercial/institutional markets are mostly concerned with air-conditioning of buildings. More applications are identified and discussed for the industrial market, including refrigeration, food-storage cooling, process cooling, and process heating at various temperature ranges from hot water for hand-washing to high-temperature (greater than 130C). Other interesting industrial applications are absorption cooling or heating combined with co-generation, desiccant cooling, gas turbine inlet air cooling, combining absorption chillers with district heating systems, direct-fired absorption heat pumps (AHPs), and a closed greenhouse concept being developed for that economically important sector in the Netherlands. Most of the sorption market at this time comprises direct-fired absorption chillers, or hot water or steam absorption chillers indirectly driven by direct-fired boilers. Throughout the report, this category of absorption chillers is referred to generically as 'direct-fired'. In addition, this report covers absorption (reversible) heat pumps, absorption heat transformers, compression-absorption heat pumps, and adsorption chillers and heat pumps. Adsorption systems together with desiccant systems are also addressed. Chapter 4, Factors Affecting the Market, considers economic, environmental and policy issues. The geographical make-up of the world sorption market is then reviewed, followed by a number of practical operating and control considerations. These include vacuum requirements, crystallisation, corrosion, maintenance, health and

  18. Spectrophotometer-Integrating-Sphere System for Computing Solar Absorptance

    Science.gov (United States)

    Witte, William G., Jr.; Slemp, Wayne S.; Perry, John E., Jr.

    1991-01-01

    A commercially available ultraviolet, visible, near-infrared spectrophotometer was modified to utilize an 8-inch-diameter modified Edwards-type integrated sphere. Software was written so that the reflectance spectra could be used to obtain solar absorptance values of 1-inch-diameter specimens. A descriptions of the system, spectral reflectance, and software for calculation of solar absorptance from reflectance data are presented.

  19. Development in fiscal 1999 of technologies to put photovoltaic power generation systems into practical use. International cooperation projects (Collection of information on IEA photovoltaic air conditioning and hot water supply program); 1999 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Kokusai kyoryoku jigyo (IEA taiyo reidanbo kyuto program ni kansuru joho shushu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This paper reports activities of collecting items of information by dispatching experts mainly composed of members of the IEA photovoltaic air conditioning, and solar heating and cooling program (SHCP) committee to the SHCP Executive Committee and the Task expert conferences. This treaty is intended to assist creating the environmentally sustainable future by utilizing solar designs and technologies. It also aims at developing solar technologies including cost reduction as a result of the joint researches with business entities, structuring international markets, providing items of information, quantifying the effectiveness to the environment, performing the international standardization, and promoting utilization of solar technologies in developing countries. The tasks now in action include architectural lighting, methods for analyzing solar architectural energies, optimization of solar energy utilization in large buildings, procurement of active solar systems, air conditioning systems in buildings using the solar energy, solar heat composite systems, expansion of exterior component materials for solar buildings, sustainable buildings, agricultural solar drying, solar cities, a hybrid heat/PV solar system. (NEDO)

  20. Simulator for design absorption refrigeration system; Simulador para projeto de ciclos de refrigeracao por absorcao

    Energy Technology Data Exchange (ETDEWEB)

    Morejon, C.F.M.; Brum, N. de C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Mecanica]. E-mails: Camilo_freddy@hotmail.com; Nisio@serv.com.ufrj.br

    2000-07-01

    This work presents a development of a thermal fluid dynamics model and a solution of a steady state absorption refrigeration cycle, with ammonia water as the working fluid. Analytical thermodynamics models expressing the enthalpy in function of pressure, temperature and composition (h=f(P,T,x)), are used with the aim to design all of the cycle devices, moved by any type of energy such as solar, natural gas, steam or electrical energy (Morejon and Hackenberg, 1978). The development of the analysis is carried out by the application of thermal fluid dynamics concepts together with a detailed study of the heat and mass transfer in the different cycle stages. The thermodynamic cycle model, obtained from equation of state for ammonia - water mixtures (Ziegker and Trepp, 1984), is represented by the relation h - x (enthalpy-composition) for different pressures and temperatures. The obtained models are used to implement computational codes in MAPLE-V facilitating the design and simulation of refrigeration system. This study can be applied in the systems of air conditioning and refrigeration chambers design. (author)

  1. Costic's technical day: thermodynamical heating and air conditioning in accommodations (heat pumps and heating/cooling floors). Air systems and their application in collective installations; Journee technique Costic: chauffage thermodynamique et climatisation dans l'habitat (les pompes a chaleur, les planchers chauffants-rafraichissants). Les systemes a air les applications en collectif

    Energy Technology Data Exchange (ETDEWEB)

    Lenotte, J.J.

    2002-07-01

    Direct expansion air systems are now currently used in individual residential houses. Some of these systems are used also in collective residential buildings where they allow to take into account the individualization of consumptions, as wished by some property developers. Some other centralized air-conditioning systems can be used. They require a distribution water loop for the supply of terminal units of ventilation-convection type. This document presents successively: the direct expansion air systems (direct emission air/air heat pumps, aeraulic distribution air/air heat pumps, production dimensioning, implementation, regulation, systems with variable flow rate of refrigerant); the centralized air/water systems with ventilation-convection systems (production dimensioning, implementation, regulation); the air distribution and diffusion. (J.S.)

  2. Second law analysis of double effect vapour absorption cooler system

    International Nuclear Information System (INIS)

    Gomri, Rabah; Hakimi, Riad

    2008-01-01

    In this paper, exergy analysis of double effect lithium bromide/water absorption refrigeration system is presented. The system consists of a second effect generator between the generator and condenser of the single effect absorption refrigeration system, including two solution heat exchangers between the absorber and the two generators. In order to simulate the refrigeration system by using a computer, a new set of computationally efficient formulations of thermodynamic properties of lithium bromide/water solution developed is used. The exergy analysis is carried out for each component of the system. All exergy losses that exist in double effect lithium bromide/water absorption system are calculated. In addition to the coefficient of performance and the exergetic efficiency of the system, the number of exergy of each component of the system is also estimated. This study suggests the component of the absorption refrigeration system that should be developed. The results show that the performance of the system increases with increasing low pressure generator (LPG) temperature, but decreases with increasing high pressure generator (HPG) temperature. The highest exergy loss occurs in the absorber and in the HPG, which therefore makes the absorber and HPG the most important components of the double effect refrigeration system

  3. Exergy analysis of heating, refrigerating and air conditioning methods and applications

    CERN Document Server

    Dincer, Ibrahim

    2015-01-01

    Improve and optimize efficiency of HVAC and related energy systems from an exergy perspective. From fundamentals to advanced applications, Exergy Analysis of Heating, Air Conditioning, and Refrigeration provides readers with a clear and concise description of exergy analysis and its many uses. Focusing on the application of exergy methods to the primary technologies for heating, refrigerating, and air conditioning, Ibrahim Dincer and Marc A. Rosen demonstrate exactly how exergy can help improve and optimize efficiency, environmental performance, and cost-effectiveness. The book also discusses the analysis tools available, and includes many comprehensive case studies on current and emerging systems and technologies for real-world examples. From introducing exergy and thermodynamic fundamentals to presenting the use of exergy methods for heating, refrigeration, and air conditioning systems, this book equips any researcher or practicing engineer with the tools needed to learn and master the application of exergy...

  4. Cosmological implications of the redshift distribution of QSO absorption systems

    International Nuclear Information System (INIS)

    Khare-Joshi, P.; Perry, J.J.

    1982-01-01

    We have used the observational data on QSO absorption redshifts, as compiled by Perry, Burbidge and Burbidge (1978) (hereafter PB 2 ), Drew (1978) and Weyman et al. (1979) (hereafter W 2 PT), to study various selection effects likely to affect the distribution of absorption redshifts and, then to determine the probable number distribution of absorbers per redshift interval of 0.1, as a function of z. The distribution obtained, assuming all the observed absorption to be intervening, is found to be statistically incompatible with the redshift distribution of galaxies with constant cross-section for any Friedman cosmology with zero cosmological constant and q 0 >= 0. Therefore, in order to eliminate the absorption systems which are plausibly intrinsic, we have applied the criterion suggested by W 2 PT and by the analysis of the distribution of absorption systems as a function of the relative velocity between the emitting and the absorbing gas, for the PB 2 data set; to wit, we have analysed the distributions obtained by assuming that those systems with relative velocity greater than 0.02 c, 0.02 c but not equal to 0.1 c to 0.11 c and 0.06 c respectively, or those systems without O VI and N V lines, are produced by the intervening galaxies. The results are discussed. (author)

  5. Optomechanically induced absorption in parity-time-symmetric optomechanical systems

    Science.gov (United States)

    Zhang, X. Y.; Guo, Y. Q.; Pei, P.; Yi, X. X.

    2017-06-01

    We explore the optomechanically induced absorption (OMIA) in a parity-time- (PT -) symmetric optomechanical system (OMS). By numerically calculating the Lyapunov exponents, we find out the stability border of the PT -symmetric OMS. The results show that in the PT -symmetric phase the system can be either stable or unstable depending on the coupling constant and the decay rate. In the PT -symmetric broken phase the system can have a stable state only for small gain rates. By calculating the transmission rate of the probe field, we find that there is an inverted optomechanically induced transparency (OMIT) at δ =-ωM and an OMIA at δ =ωM for the PT -symmetric optomechanical system. At each side of δ =-ωM there is an absorption window due to the resonance absorption of the two generated supermodes. Comparing with the case of optomechanics coupled to a passive cavity, we find that the active cavity can enhance the resonance absorption. The absorption rate at δ =ωM increases as the coupling strength between the two cavities increases. Our work provides us with a promising platform for controlling light propagation and light manipulation in terms of PT symmetry, which might have potential applications in quantum information processing and quantum optical devices.

  6. Numerical Analysis of Exergy for Air-Conditioning Influenced by Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Jing-Nang Lee

    2014-07-01

    Full Text Available The article presents numerical analysis of exergy for air-conditioning influenced by ambient temperature. The model of numerical simulation uses an integrated air conditioning system exposed in varied ambient temperature to observe change of the four main devices, the compressor, the condenser, the capillary, and the evaporator in correspondence to ambient temperature. The analysis devices of the four devices’s exergy influenced by the varied ambient temperature and found that the capillary has unusual increasing exergy loss vs. increasing ambient temperature in comparison to the other devices. The result shows that reducing exergy loss of the capillary influenced by the ambient temperature is the key for improving working efficiency of an air-conditioning system when influence of the ambient temperature is considered. The higher ambient temperature causes the larger pressure drop of capillary and more exergy loss.

  7. A solar collector for air-conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kose, E. [Microtherm Energietechnik GmbH, 25 - Lods (France)

    1999-03-01

    A high performance Compound Parabolic Concentrator (CPC) collector is presented. It comprises dewar type tubular vacuum tubes with an absorber coating of very low emittance, a moderately concentrating reflector and a simple thermosyphon heat removal system. The reflectors car be designed with respect to the specific needs; reflector material, concentration, truncation and symmetry car be chosen freely. The collector allows the construction of cooling systems with higher COP's without using tracking systems. Land use and costs are greatly reduced. For a certain application (optimum yearly gain in Munich with a constant collector temperature of 180 deg C) the reflector was optimized, it is a fairly asymmetrical design. A symmetrical design with a similar performance has been tested, the results are shown. (author)

  8. 2013 German refrigeration and air conditioning meeting. Proceedings

    International Nuclear Information System (INIS)

    2013-01-01

    These proceedings cover the following main topics: cryoengineering - superconduction / energy storage; cryoapplications in biology and medicine; metrology; adsorption processes; condensation/evaporation; working fluids / simulation; ice production; plants and compressors; expansion and ejectors or recooling; use of cooling (passenger car air conditioning, supermarket); refrigerants; plant efficiency; emissions and legislation; air conditioning and use of heat pumps; air quality and control; building technology and block-type thermal power stations. [de

  9. 2014 German refrigeration and air conditioning meeting. Proceedings

    International Nuclear Information System (INIS)

    2014-01-01

    The proceedings of the 2014 German refrigeration and air conditioning meeting contain contributions on the following topics: cryotechnology, fundamentals and materials for the refrigeration and heat pump technology, devices and components for the refrigeration and heat pump technology, applications of refrigeration technologies, air conditioning technology and heat pump applications, cryotechnology in biology and medicine, heat transfer and ventilation, guidelines and legal topics, refrigerant fluid - oil mixtures, control and surveillance, simulation and control, ambient air.

  10. Multiple wavelength multitimescale optical absorption system

    International Nuclear Information System (INIS)

    Lubis, R.; Allan, D.; Hodgson, B.W.; Swallow, A.J.

    1992-01-01

    A new workstation for pulse radiolysis studies has been developed for the Paterson Institute Linear Accelerator Laboratory. It is particularly suited to the study of materials available only in limited quantities. The analysing light beam is dispersed into a plane spectrum by a McPherson 270 monochromator and focused down to a line spectrum by a rod lens. The spectral intensity distribution is sampled by a linear array of optical fibres which conduct the light to photodiodes. A preamplifier unit amplifies and buffers the diode photocurrent signal which then passes to the main electronics unit incorporating further amplification stages, filters, backing-off of the background photocurrent, analog-to-digital conversion, data storage memory and a computer interface. All control of the electronic system is performed from a computer equipped with appropriate software. The system has 10 channels of spectral bandwidth 16 nm, a useful spectral response from 350 nm to 1 μm with a high signal-to-noise ratio, signal sampling rates from 20 MHz to 2 kHz and 8 kbyte of local memory for each channel. (author)

  11. Multiple wavelength multitimescale optical absorption system

    Science.gov (United States)

    Lubis, R.; Allan, D.; Hodgson, B. W.; Swallow, A. J.

    A new workstation for pulse radiolysis studies has been developed for the Paterson Institute Linear Accelerator Laboratory. It is particularly suited to the study of materials available only in limited quantities. The analysing light beam is dispersed into a plane spectrum by a McPherson 270 monochromator and focused down to a line spectrum by a rod lens. The spectral intensity distribution is sampled by a linear array of optical fibres which conduct the light to photodiodes. A preamplifier unit amplifies and buffers the diode photocurrent signal which then passes to the main electronics unit incorporating further amplification stages, filters, backing-off of the background photocurrent, analog-to-digital conversion, data storage memory and a computer interface. All control of the electronic system is performed from a computer equipped with appropriate software. The system has 10 channels of spectral bandwidth 16 nm, a useful spectral response from 350 nm to 1 μm with a high signal-to-noise ratio, signal sampling rates from 20 MHz to 2 kHz and 8 kbyte of local memory for each channel.

  12. HFC perspectives in air-conditioning and refrigeration; Perspectives HFC en A/C et refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Fauvarque, P [ELF Atochem, Centre d` Application de Lavallois, 92 (France)

    1998-12-31

    This paper is a series of transparencies dealing with the development of substitutes for the replacement of the R-22 refrigerant in air-conditioning systems (R-134a, R-407C, R-410A), and in industrial refrigeration systems of agriculture and food industry (R-134a and R-404A). (J.S.)

  13. HFC perspectives in air-conditioning and refrigeration; Perspectives HFC en A/C et refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Fauvarque, P. [ELF Atochem, Centre d`Application de Lavallois, 92 (France)

    1997-12-31

    This paper is a series of transparencies dealing with the development of substitutes for the replacement of the R-22 refrigerant in air-conditioning systems (R-134a, R-407C, R-410A), and in industrial refrigeration systems of agriculture and food industry (R-134a and R-404A). (J.S.)

  14. Anti-seismic air condition's cooling capability increase of the second control area

    International Nuclear Information System (INIS)

    Pan Qiang

    2008-01-01

    Secondary area (SCA) air-conditioning system is an important ventilation system in plant. It should achieve the indoor temperature controllable. To resolve the problem of cooling capacity insufficiency, on the basis of ventilation and refrigeration theory, the thesis analyzes the design modification plan. (author)

  15. Computational Model of a Biomass Driven Absorption Refrigeration System

    Directory of Open Access Journals (Sweden)

    Munyeowaji Mbikan

    2017-02-01

    Full Text Available The impact of vapour compression refrigeration is the main push for scientists to find an alternative sustainable technology. Vapour absorption is an ideal technology which makes use of waste heat or renewable heat, such as biomass, to drive absorption chillers from medium to large applications. In this paper, the aim was to investigate the feasibility of a biomass driven aqua-ammonia absorption system. An estimation of the solid biomass fuel quantity required to provide heat for the operation of a vapour absorption refrigeration cycle (VARC is presented; the quantity of biomass required depends on the fuel density and the efficiency of the combustion and heat transfer systems. A single-stage aqua-ammonia refrigeration system analysis routine was developed to evaluate the system performance and ascertain the rate of energy transfer required to operate the system, and hence, the biomass quantity needed. In conclusion, this study demonstrated the results of the performance of a computational model of an aqua-ammonia system under a range of parameters. The model showed good agreement with published experimental data.

  16. Prediction of thermal sensation in non-air-conditioned buildings in warm climates

    DEFF Research Database (Denmark)

    Fanger, Povl Ole; Toftum, Jørn

    2002-01-01

    The PMV model agrees well with high-quality field studies in buildings with HVAC systems, situated in cold, temperate and warm climates, studied during both summer and winter. In non-air-conditioned buildings in warm climates, occupants may sense the warmth as being less severe than the PMV...... predicts. The main reason is low expectations, but a metabolic rate that is estimated too high can also contribute to explaining the difference. An extension of the PMV model that includes an expectancy factor is introduced for use in non-air-conditioned buildings in warm climates. The extended PMV model...... agrees well with quality field studies in non-air-conditioned buildings of three continents....

  17. Extension of the PMV model to non-air-conditioned building in warm climates

    DEFF Research Database (Denmark)

    Fanger, Povl Ole; Toftum, Jørn

    2002-01-01

    The PMV model agrees well with high-quality field studies in buildings with HVAC systems, situated in cold, temperate and warm climates, studied during both summer and winter. In non-air-conditioned buildings in warm climates, occupants may sense the warmth as being less severe than the PMV...... predicts. The main reason is low expectations, but a metabolic rate that is estimated too high can also contribute to explaining the difference. An extension of the PMV model that includes an expectancy factor is introduced for use in non-air-conditioned buildings in warm climates. The extended PMV model...... agrees well with quality field studies in non-air-conditioned buildings of three continents....

  18. Studies of Radon and Radon Progeny in Air Conditioned Rooms in Hospitals

    International Nuclear Information System (INIS)

    Marley, F.; Denman, A.R.; Phillips, P.S.

    1998-01-01

    A series of continuous real-time radon and radon progeny measurements together with passive etched track detector measurements were performed in hospital premises during 1996. In one small room, detailed measurements over several weeks showed that both the radon concentration and the Equilibrium Factor depended on the intermittent operation of a filtered positive pressure displacement air-conditioning system, which was designed to conform to operating theatre standards. The average radon level measured while the air-conditioning was off was almost four times higher than that recorded whilst it was on. The progeny level was over five times higher than that whilst it was on. Thus, the Equilibrium Factor (F), was significantly lower when the air-conditioning was on. Measurements in similar rooms in two hospitals, confirmed that the reduction in radon level was a general finding. Thus staff working in such environments receive significantly lower radiation dose from radon than staff working in nearby normally ventilated rooms. (author)

  19. Decoupling dehumidification and cooling for energy saving and desirable space air conditions in hot and humid Hong Kong

    International Nuclear Information System (INIS)

    Lee, W.L.; Chen Hua; Leung, Y.C.; Zhang, Y.

    2012-01-01

    Highlights: ► The combined use of dedicated ventilation and dry cooling (DCDV) system was investigated. ► Investigations were based actual equipment performance data and realistic building and system characteristics. ► DCDV system could save 54% of the annual energy use for air-conditioning. ► DCDV system could better achieve the desired space air conditions. ► DCDV system could decouple dehumidification and cooling. - Abstract: The combined use of dedicated outdoor air ventilation (DV) and dry cooling (DC) air-conditioning system to decouple sensible and latent cooling for desirable space air conditions, better indoor air quality, and energy efficiency is proposed for hot and humid climates like Hong Kong. In this study, the performance and energy saving potential of DCDV system in comparison to conventional systems (constant air volume (CAV) system with and without reheat) for air conditioning of a typical office building in Hong Kong are evaluated. Through hour-by-hour simulations, using actual equipment performance data and realistic building and system characteristics, the cooling load profile, resultant indoor air conditions, condensation at the DC coil, and energy consumptions are calculated and analyzed. The results indicate that with the use of DCDV system, the desirable indoor conditions could be achieved and the annual energy use could be reduced by 54% over CAV system with reheat. The condensate-free characteristic at the DC coil to reduce risk of catching disease could also be realized.

  20. FY 1977 Annual report on Sunshine Project results. Research and development of solar energy systems for air conditioning and hot water supply (Research and development of solar systems for existing residential buildings); 1977 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Kison kojin jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-05-31

    As part of the research and development of the solar energy systems for air conditioning and hot water supply for existing residential buildings, the following efforts are made: (1) system analysis, (2) studies on devices and materials, and (3) installation and operation of the facilities in test buildings, and collection of the data. For the item (1), the sensible heat type heat-accumulating tank is replaced by the latent heat type to reduce heat losses and auxiliary power requirements by improving heat-accumulating tank efficiency and revising the control procedure. For the item (2), the devices installed in the test buildings are tested to improve their performance and reliability, in which, e.g., results of operation, under commercial conditions, of the Rankine cycle refrigerator installed in the test building are taken into consideration. The empirical correlation {eta} 0.66 - 1.7{delta}T/I is obtained for instantaneous heat-collecting efficiency of a vacuum collector, made on a trial basis. Its heat loss is sufficiently small, which is in agreement with the results of the nighttime heat release tests. For the latent heat type heat-accumulating tank, stability of the materials therefor are investigated. For the Rankine cycle refrigerator, development of its parts is continued. For the item (3), the facilities are tested for around 7 months, and problems involved in each device are clarified. (NEDO)

  1. Air condition sensor on KNX network

    Science.gov (United States)

    Gecova, Katerina; Vala, David; Slanina, Zdenek; Walendziuk, Wojciech

    2017-08-01

    One of the main goals of modern buildings in addition to the management environment is also attempt to save energy. For this reason, increased demands on the prevention of energy loss, which can be expressed for example as an inefficient use of the available functions as a building or heat leakage. Reducing heat loss as a perfect tightness of doors and windows in the building, however, restricts the natural ventilation, which leads to a gradual deterioration of the quality of the internal environment. This state then has a very significant impact on human health. In the closed, poorly ventilated area, the person staying at increasing the carbon dioxide concentration, temperature and humidity, which impacts the human thermoregulation system, increases fatigue and causes restlessness. It is therefore necessary to monitor these parameters and then control so as to ensure stable and optimal human values. The aim is to design and implementation Module sensors that will be able to measure different parameters, allowing the subsequent regulation of indoor environmental quality.

  2. Thermodynamic simulation of ammonia-water absorption refrigeration system

    Directory of Open Access Journals (Sweden)

    Sathyabhama A.

    2008-01-01

    Full Text Available The ammonia-water absorption refrigeration system is attracting increasing research interests, since the system can be powered by waste thermal energy, thus reducing demand on electricity supply. The development of this technology demands reliable and effective system simulations. In this work, a thermodynamic simulation of the cycle is carried out to investigate the effects of different operating variables on the performance of the cycle. A computer program in C language is written for the performance analysis of the cycle.

  3. Central air conditioning based on adsorption and solar energy

    International Nuclear Information System (INIS)

    Pralon Ferreira Leite, Antonio; Belo, Francisco Antonio; Martins, Moacir Machado; Bressan Riffel, Douglas

    2011-01-01

    This paper presents the characterization and the pre-dimensioning of an adsorption chiller as part of a 20 kW air conditioning central unit for cooling a set of rooms that comprises an area of 110 m 2 . The system is basically made up of a cold water storage tank supplied by an activated carbon-methanol adsorption chiller, a hot water storage tank, fed by solar energy and natural gas, and a fan-coil. During an acclimatization of 8 h (9-17 h), the following parameters were obtained for dimensioning the cooling system: 504 kg of activated carbon, 180 L of methanol, 7000 L of hot water, 10,300 L of cold water with its temperature varying in the fan-coil from 1 deg. C to 14 C. Considering the mean value of the total daily irradiation in Joao Pessoa (7 o 8'S, 34 o 50'WG), and a cover of regenerating heat supplied by solar energy equivalent to 70%, the adsorption chiller's expected coefficient of performance (COP) was found to be around 0.6.

  4. Simulation of solar-powered absorption cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Atmaca, I.; Yigit, A. [Uludag Univ., Bursa (Turkey). Dept. of Mechanical Engineering

    2003-07-01

    With developing technology and the rapid increase in world population, the demand for energy is ever increasing. Conventional energy will not be enough to meet the continuously increasing need for energy in the future. In this case, renewable energy sources will become important. Solar energy is a very important energy source because of its advantages. Instead of a compressor system, which uses electricity, an absorption cooling system, using renewable energy and kinds of waste heat energy, may be used for cooling. In this study, a solar-powered, single stage, absorption cooling system, using a water-lithium bromide solution, is simulated. A modular computer program has been developed for the absorption system to simulate various cycle configurations and solar energy parameters for Antalya, Turkey. So, the effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the absorption cooling components are studied. In addition, reference temperatures which are the minimum allowable hot water inlet temperatures are determined and their effect on the fraction of the total load met by non-purchased energy (FNP) and the coefficient of performance are researched. Also, the effects of the collector type and storage tank mass are investigated in detail. (author)

  5. Cooling performance and energy saving of a compression-absorption refrigeration system driven by a gas engine

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Z.G.; Guo, K.H. [Sun Yat-Sen University, Guangzhou (China). Engineering School

    2006-07-01

    The prototype of combined vapour compression-absorption refrigeration system was set up, where a gas engine drove directly an open screw compressor in a vapour compression refrigeration chiller and waste heat from the gas engine was used to operate absorption refrigeration cycle. The experimental procedure and results showed that the combined refrigeration system was feasible. The cooling capacity of the prototype reached about 589 kW at the Chinese rated conditions of air conditioning (the inlet and outlet temperatures of chilled water are 12 and 7{sup o}C, the inlet and outlet temperatures of cooling water are 30 and 35{sup o}C, respectively). Primary energy rate (PER) and comparative primary energy saving were used to evaluate energy utilization efficiency of the combined refrigeration system. The calculated results showed that the PER of the prototype was about 1.81 and the prototype saved more than 25% of primary energy compared to a conventional electrically driven vapour compression refrigeration unit. Error analysis showed that the total error of the combined cooling system measurement was about 4.2% in this work. (author)

  6. Use of process steam in vapor absorption refrigeration system for cooling and heating applications: An exergy analysis

    Directory of Open Access Journals (Sweden)

    S. Anand

    2016-12-01

    Full Text Available The exponential increase in cost of conventional fuels shifts the interest toward the use of alternative as well waste energy sources for the operation of refrigeration and air-conditioning units. The present study therefore analyzes the performance of a process steam-operated vapor absorption system for cooling and heating applications using ammonia and water as working fluids based on first and second laws of thermodynamics. A mathematical model has been developed based on exergy analysis to investigate the performance of the system. The different performance parameters such as coefficient of performance (COP and exergetic efficiency of absorption system for cooling and heating applications are also calculated under different operating conditions. The results obtained show that cooling and heating COP along with second law efficiency (exergy efficiency increases with the heat source temperature at constant evaporator, condenser, and absorber temperature. Also, COP as well as exergy efficiency increases with an increase in the evaporator temperature at constant generator, condenser, and absorber temperature. The effect of ambient temperature on the exergetic efficiency for cooling and heating applications is also studied. The results obtained from the simulation studies can be used to optimize different components of the system so that the performance can be improved significantly.

  7. Backscatter absorption gas imaging systems and light sources therefore

    Science.gov (United States)

    Kulp, Thomas Jan [Livermore, CA; Kliner, Dahv A. V. [San Ramon, CA; Sommers, Ricky [Oakley, CA; Goers, Uta-Barbara [Campbell, NY; Armstrong, Karla M [Livermore, CA

    2006-12-19

    The location of gases that are not visible to the unaided human eye can be determined using tuned light sources that spectroscopically probe the gases and cameras that can provide images corresponding to the absorption of the gases. The present invention is a light source for a backscatter absorption gas imaging (BAGI) system, and a light source incorporating the light source, that can be used to remotely detect and produce images of "invisible" gases. The inventive light source has a light producing element, an optical amplifier, and an optical parametric oscillator to generate wavelength tunable light in the IR. By using a multi-mode light source and an amplifier that operates using 915 nm pump sources, the power consumption of the light source is reduced to a level that can be operated by batteries for long periods of time. In addition, the light source is tunable over the absorption bands of many hydrocarbons, making it useful for detecting hazardous gases.

  8. Lack of dust in quasar absorption line systems

    International Nuclear Information System (INIS)

    Jura, M.

    1977-01-01

    It is stated that the origin of absorption line systems in quasars is still uncertain. Most such systems apparently have atomic hydrogen column densities of the order of 10 19 /cm 2 , but at least two quasars, 1331 + 170 and PHL957, have such strong Lyman α absorption lines that atomic hydrogen column densities of the order of 10 21 /cm 2 are indicated. It should be possible to observe the dust produced 2,200 A extinction feature as it is red shifted into the visible, and to determine whether absorption line systems are produced in spiral galaxies where the dust content is similar to that in the interstellar medium. It has been argued that the emission line regions of quasars generally lack dust and that towards PHL957 the 2,200 A feature is absent. The present author argues that dust similar to that found in the interstellar medium is not found towards the quasars 1331 + 170 and PHL957. This could explain why H 2 is not found towards PHL957, and it indicates that the absorption line systems in quasars are not produced in spiral galaxies similar to our own. It seems from the analysis presented that the dust-to-gas ratio towards 1331 + 170 is at least a factor of 20 less than in the interstellar medium, and there is no reason to suppose that this lack of dust results from a lack of metals It is concluded that there seems to be a lack of normal dust towards PHL957 by at least a factor of two; and that the absorption region towards 1331 + 170 and probably the region towards PHL957 are lacking dust similar to that in our own galaxy. This can explain the lack of H 2 in these systems. (U.K.)

  9. Effects of suspension of air-conditioning on airtight-type racks.

    Science.gov (United States)

    Kanzaki, M; Fujieda, M; Furukawa, T

    2001-10-01

    Although isolation racks are superior to open-type racks in terms of securing breeding conditions for laboratory animals, the contingency-proofing capability of the former has yet to be determined. Therefore, from the view of risk management, we studied the environmental change in isolation racks by forcibly suspending ventilation and air-conditioning and confirming the maximal time length for complete recovery to the original condition after restarting their operations. The isolation racks were placed in a room that was equipped with an independent air-conditioning system. When the inside condition of the racks reached 22-24 degrees C and 59-64% of relative humidity, the air-conditioning and ventilation were forcibly suspended and the subsequent temperature, relative humidity, ammonium and CO2 concentrations in the racks were measured over time. We found that after suspending the air-conditioning and ventilation, it took 40-60 min for temperature, and about 10 min for relative humidity to exceed the maximum values (temperature and relative humidity) referred to in the Showa 58 Nenban Guideline Jikken Doubutsu Shisetsu no Kenchiku oyobi Setsubi (Guidelines of buildings and facilities for experimental animals in Japan; Year 1983 edition). After 17 hr 25 min of the suspension of air-conditioning and ventilation, two rats were found dead. Then, the air-conditioning and ventilation were restarted. It took about 2 hr for temperature, and 50 min for relative humidity to regain the guideline values. The ammonium concentration stayed within the guideline value with a maximum concentration of 2 ppm in the experimental period, whereas the CO2 concentration was found to exceed 9% at the time of animal death.

  10. Subsurface Thermal Energy Storage for Improved Heating and Air Conditioning Efficiency

    Science.gov (United States)

    2016-11-21

    through water evaporation , although some cooling also occurs due to sensible heat transfer . Cooling towers are very effective heat transfer devices... evaporator coil connected to the building heating , ventilation, and air conditioning (HVAC) system. The refrigerant evaporates in the coil, removing...vapor is directed to a condensing coil, where the refrigerant vapor condenses back into a liquid, releasing its heat of vaporization. During

  11. Thermal design of a modern, air-conditioned, single-floor, solar-powered desert house

    KAUST Repository

    Serag-Eldin, M. A.

    2011-01-01

    The paper presents a thermal analysis of a single-floor, solar-powered desert house. The house is air-conditioned and provides all modern comforts and facilities. Electrical power, which drives the entire energy system, is generated by roof

  12. Heat pipe heat exchanger for heat recovery in air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Baky, Mostafa A.; Mohamed, Mousa M. [Mechanical Power Engineering Department, Faculty of Engineering, Minufiya University, Shebin El-Kom (Egypt)

    2007-03-15

    The heat pipe heat exchangers are used in heat recovery applications to cool the incoming fresh air in air conditioning applications. Two streams of fresh and return air have been connected with heat pipe heat exchanger to investigate the thermal performance and effectiveness of heat recovery system. Ratios of mass flow rate between return and fresh air of 1, 1.5 and 2.3 have been adapted to validate the heat transfer and the temperature change of fresh air. Fresh air inlet temperature of 32-40{sup o}C has been controlled, while the inlet return air temperature is kept constant at about 26{sup o}C. The results showed that the temperature changes of fresh and return air are increased with the increase of inlet temperature of fresh air. The effectiveness and heat transfer for both evaporator and condenser sections are also increased to about 48%, when the inlet fresh air temperature is increased to 40{sup o}C. The effect of mass flow rate ratio on effectiveness is positive for evaporator side and negative for condenser side. The enthalpy ratio between the heat recovery and conventional air mixing is increased to about 85% with increasing fresh air inlet temperature. The optimum effectiveness of heat pipe heat exchanger is estimated and compared with the present experimental data. The results showed that the effectiveness is close to the optimum effectiveness at fresh air inlet temperature near the fluid operating temperature of heat pipes. (author)

  13. DISAIN SIMULATOR AUTOMOTIVE AIR CONDITIONING UNTUK MENINGKATKAN KOMPETENSI MAHASISWA

    Directory of Open Access Journals (Sweden)

    Kamin Sumardi

    2015-08-01

    Full Text Available Perkembangan teknologi automotive air conditioning dan aplikasinya sangat cepat, salah satunya dengan menerapkan green technology. Penerapan green technology pada teknologi air conditioning, karena masih menggunakan refrigeran yang mengandung unsur kimia yang merusak lapisan ozon dan pemanasan global. Alih teknologi bidang air conditioning yang ramah lingkungan, belum dibarengi dengan ketersediaan tenaga kerja pada tingkat SMK dan perguruan tinggi yang memadai, baik kuantitas maupun kompetensinya. Pada level SMK dan perguruan tinggi, kompetensi akademik dan vokasional bidang automotive air conditioning harus terus ditingkatkan dan diperbaharui sesuai dengan perkembangan teknologinya. Penelitian ini bertujuan untuk menghasilkan simulator automotive air conditioner dan model pembelajaran tata udara pada otomotif berwawasan teknologi ramah lingkungan. Penelitian menggunakan metode research and development dengan langkah-langkah: studi pendahuluan, perencanaan, pengembangan melalui uji coba simulator, validasi, dan produk akhir. Simulator dibuat sesuai dengan kondisi di dunia kerja agar tidak terjadi miskonsepsi dan mala-praktek automotive air conditioning. Simulator ini dibuat secara kompak dan mobile atau dapat dipindah dan dibawa. Model pembelajaran disesuaikan dengan kebutuhan kompetensi yang dipersyaratkan. Hasil penelitian menunjukkan bahwa dengan bantuan simulator automotive air conditioner dan model pembelajaran yang tepat mahasiswa mampu menyerap konsep dan praktek lebih cepat 85%. Hasil belajar pada ranah afektif, kognitif, psikomotor dan kompetensi meningkat secara signifikan.

  14. Evolution of absorption machines; Evolution des machines a absorption

    Energy Technology Data Exchange (ETDEWEB)

    Soide, I; Klemsdal, E [Gaz de France (GDF), 75 - Paris (France); Le Goff, P; Hornut, J M [LSGC-ENSIC, 54 - Nancy (France)

    1998-12-31

    Most of todays absorption air-conditioning machineries use the lithium bromide-water pair. The most performing can operate at a 150-160 deg. C, the temperature being limited by the corrosion resistance of metals with respect to LiBr solutions. Also, there is a revival of interest for water-ammonia systems. These systems require the use of a rectification column which reduces the coefficient of performance. Higher thermal performances are reached with hydrocarbon pairs and ternary mixtures (water-methanol-LiBr etc..). This paper presents different schemes of refrigerating heat pumps based on these different systems. (J.S.)

  15. Evolution of absorption machines; Evolution des machines a absorption

    Energy Technology Data Exchange (ETDEWEB)

    Soide, I.; Klemsdal, E. [Gaz de France (GDF), 75 - Paris (France); Le Goff, P.; Hornut, J.M. [LSGC-ENSIC, 54 - Nancy (France)

    1997-12-31

    Most of todays absorption air-conditioning machineries use the lithium bromide-water pair. The most performing can operate at a 150-160 deg. C, the temperature being limited by the corrosion resistance of metals with respect to LiBr solutions. Also, there is a revival of interest for water-ammonia systems. These systems require the use of a rectification column which reduces the coefficient of performance. Higher thermal performances are reached with hydrocarbon pairs and ternary mixtures (water-methanol-LiBr etc..). This paper presents different schemes of refrigerating heat pumps based on these different systems. (J.S.)

  16. 2012 German refrigeration and air conditioning meeting. Proceedings; Deutsche Kaelte-Klima-Tagung 2012 Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Within the DKV conference of the Deutscher Kaelte- und Klimatechnischer Verein e.V. (Hanover, Federal Republic of Germany) from 21st to 23rd November, 2012, in Wuerzburg (Federal Republic of Germany) 121 lectures were held according to the following themes: Measurement and process control in cryotechnology; energy storage and energy application; application of cryotechnology in biology and medicine, new concepts and plants; fundamentals and materials for the technology of cold pumps and heat pumps - pool boiling; flow boiling / CO{sub 2}; adsorption processes; adsorption processes / phase change materials; condensation / dehumidification; plants and components of the technology of cold pumps and heat pumps - compressors; expansion and regulation; heat exchanger and reflux cooling; heat exchangers; systems simulation; systems and materials; application of cold - energy controlling / application; foodstuff / supermarket; air conditionings of passenger cars; air-conditioning of electric-powered automobiles; railway air-conditioning / system analyses; standardization and regulations; air conditioning and application of heat pumps - regulation / hardware-in-the-loop; net-zero-energy building; building engineering and simulation; standardization / IAQ / building materials; heat pumps; thermal comfort and performance in office accommodations.

  17. Geothermal as a heat sink application for raising air conditioning efficency

    Science.gov (United States)

    Ibrahim, Hesham Safwat Osman Mohamed

    2016-04-01

    Objective: Geothermal applications in heating, ventilation, air-conditioning is a US technology for more than 30 years old ,which saves more than 30% average energy cost than the traditional air-conditioning systems systems. Applying this technology in Middle East and African countries would be very feasible specially in Egypt specially as it suffers Electric crisis --The temperature of the condensers and the heat rejecting equipment is much higher than the Egyptian land at different depth which is a great advantages, and must be measured, recorded, and studied accurately -The Far goal of the proposal is to construct from soil analysis a temperature gradient map for Egypt and , African countries on different depth till 100 m which is still unclear nowadays and must be measured and recorded in databases through researches - The main model of the research is to study the heat transfer gradient through the ground earth borehole,grout,high density polyethylene pipes , and water inlet temperature which affect the electric efficiency of the ground source heat pump air conditioning unit Impact on the Region: Such research result will contribute widely in Energy saving sector specially the air conditioning sector in Egypt and the African countries which consumes more than 30% of the electric consumption of the total consumption . and encouraging Green systems such Geothermal to be applied

  18. Performance of a compact solar absorption cooling system

    International Nuclear Information System (INIS)

    Mulyanef; Kamaruzzaman Sopian

    2006-01-01

    This paper describes the performance of a compact solar absorption system. Purpose of compact solar is collector, generator and condenser in one unit. At present, two types of absorption cooling systems are marketed: the lithium bromide-water system and the ammonia-water system. In the lithium bromide-water system, water vapor is the refrigerant and ammonia water system where ammonia is the refrigerant. In addition, the ammonia-water system requires higher generator temperature 120 o C to 150 o C than a flat-plate solar collector can provide without special techniques. The lithium bromide-water system operates satisfactorily at a generator temperature of 75 o C to 100 o C, achievable by a flat-plate collector. The lithium bromide-water system also has a higher COP than the ammonia-water system. The disadvantage of the lithium bromide-water systems is that the evaporators cannot operate at temperature below 0 o C since the refrigerant is water. The Coefficient of Performance (COP) system is 0.62 and the concentration of LiBr-H 2 O is 50%

  19. Thermal conditions and perceived air quality in an air-conditioned auditorium

    Science.gov (United States)

    Polednik, Bernard; Guz, Łukasz; Skwarczyński, Mariusz; Dudzińska, Marzenna R.

    2016-07-01

    The study reports measurements of indoor air temperature (T) and relative humidity (RH), perceived air quality (PAQ) and CO2, fine aerosol particle number (PN) and mass (PM1) concentrations in an air conditioned auditorium. The measurements of these air physical parameters have been carried out in the unoccupied auditorium with the air conditioning system switched off (AC off mode) and in the unoccupied and occupied auditorium with the air conditioning system switched off during the night and switched on during the day (AC on/off mode). The average indoor air thermal parameters, CO2 concentration and the PAQ value (in decipols) were elevated, while average PM1 concentration was lower in the AC on/off mode. A statistically significant (p PAQ values and CO2 concentrations (r = 0.66 and r = 0.59, respectively) in that AC mode. A significant negative correlation has been observed between T and PN and PM1 concentrations (r = -0.38 and r = -0.49, respectively). In the AC off mode the above relations between T and the particle concentrations were not that unequivocal. These findings may be of importance as they indicate that in certain AC operation modes the indoor air quality deteriorates along with the variation of the indoor air microclimate and room occupation. This, in turn, may adversely affect the comfort and productivity of the users of air conditioned premises.

  20. SIMULATION OF SOLAR LITHIUM BROMIDE–WATER ABSORPTION COOLING SYSTEM WITH DOUBLE GLAZED FLAT PLATE COLLECTOR FOR ADRAR

    Directory of Open Access Journals (Sweden)

    ML CHOUGUI

    2014-12-01

    Full Text Available Adrar is a city in the Sahara desert, in southern Algeria known for its hot and dry climate, where a huge amount of energy is used for air conditioning. The aim of this research is to simulate a single effect lithium bromide–water absorption chiller coupled to a double-glazed flat plate collector to supply the cooling loads for a house of 200m2 in Adrar. The thermal energy is stored in an insulated thermal storage tank. The system was designed to cover a cooling load of 10.39KW for design day of July. Thermodynamic model was established to simulate the absorption cycle. The results have shown that the collector mass flow rate has a negligible effect on the minimum required collector area, but it has a significant effect on the optimum capacity of the storage tank. The minimum required collector area was about 65.3 m2, which could supply the cooling loads for the sunshine hours of the design day for July. The operation of the system has also been considered after sunset by saving solar energy.

  1. Economic performance optimization of an absorption cooling system under uncertainty

    International Nuclear Information System (INIS)

    Gebreslassie, Berhane H.; Guillen-Gosalbez, Gonzalo; Jimenez, Laureano; Boer, Dieter

    2009-01-01

    Many of the strategies devised so far to address the optimization of energy systems are deterministic approaches that rely on estimated data. However, in real world applications there are many sources of uncertainty that introduce variability into the decision-making problem. Within this general context, we propose a novel approach to address the design of absorption cooling systems under uncertainty in the energy cost. As opposed to other approaches that optimize the expected performance of the system as a single objective, in our method the design task is formulated as a stochastic bi-criteria non-linear optimization problem that simultaneously accounts for the minimization of the expected total cost and the financial risk associated with the investment. The latter criterion is measured by the downside risk, which avoids the need to define binary variables thus improving the computational performance of the model. The capabilities of the proposed modeling framework and solution strategy are illustrated in a case study problem that addresses the design of a typical absorption cooling system. Numerical results demonstrate that the method presented allows to manage the risk level effectively by varying the area of the heat exchangers of the absorption cycle. Specifically, our strategy allows identifying the optimal values of the operating and design variables of the cycle that make it less sensitive to fluctuations in the energy price, thus improving its robustness in the face of uncertainty.

  2. Influence of different outdoor design conditions on design cooling load and design capacities of air conditioning equipments

    International Nuclear Information System (INIS)

    Aktacir, Mehmet Azmi; Bueyuekalaca, Orhan; Bulut, Huesamettin; Yilmaz, Tuncay

    2008-01-01

    Outdoor design conditions are important parameters for energy efficiency of buildings. The result of incorrect selection of outdoor design conditions can be dramatic in view of comfort and energy consumption. In this study, the influence of different outdoor design conditions on air conditioning systems is investigated. For this purpose, cooling loads and capacities of air conditioning equipments for a sample building located in Adana, Turkey are calculated using different outdoor design conditions recommended by ASHRAE, the current design data used in Turkey and the daily maximum dry and wet bulb temperatures of July 21st, which is generally accepted as the design day. The cooling coil capacities obtained from the different outdoor design conditions considered in this study are compared with each other. The cost analysis of air conditioning systems is also performed. It is seen that the selection of outdoor design conditions is a very critical step in calculation of the building cooling loads and design capacities of air conditioning equipments

  3. Solar hybrid cooling system for high-tech offices in subtropical climate - Radiant cooling by absorption refrigeration and desiccant dehumidification

    International Nuclear Information System (INIS)

    Fong, K.F.; Chow, T.T.; Lee, C.K.; Lin, Z.; Chan, L.S.

    2011-01-01

    consumption of the solar hybrid cooling system was lower than that of the conventional vapour compression refrigeration system up to 36.5%. Between the two options of chilled ceilings, the passive chilled beams were more energy-efficient to work with the solar hybrid cooling system in the hot and humid climate. Harnessing solar energy for driving air-conditioning would help in reducing the carbon emission, hence alleviating the climate change.

  4. Absorption in multiple scattering systems of coated spheres: design applications

    International Nuclear Information System (INIS)

    Stout, Brian; Andraud, Christine; Stout, Sophie; Lafait, Jacques

    2003-01-01

    We illustrate the utility of some recently derived transfer matrix methods for electromagnetic scattering calculations in systems composed of coated spherical scatterers. Any of the spherical coatings, cores, or host media may be composed of absorbing materials. Our formulae permit the calculation of local absorption in either orientation fixed or orientation averaged situations. We introduce methods for estimating the macroscopic transport properties of such media, and show how our scattering calculations can permit 'design' optimization of macroscopic properties

  5. Analisa Performansi Sistem Air Conditioning Mobil tipe ET 450 dengan Variasi Tekanan Kerja Kompresor

    Directory of Open Access Journals (Sweden)

    Adi Purnawan

    2012-11-01

    Full Text Available Comfort and coolness when traveling by vehicle especially car is highly needed. So many attempts have been made byhumans that comfortable traveling by car can be achieved. One of the effective ways in which comfortable traveling by car can beobtained is by installing air conditioning. The performance of air conditioning system is highly influenced by how the compressorworks. In other words, the pressure resulting from the suction highly determines the performance of air conditioning system,which then affects how the compressor works, the compressor power, the refrigeration effect, the efficiency of isentropic andcoefficient of performance (COP of the car air conditioning sytem especially that of the car air conditioner type ET 450. Fromwhat has been described above, the writer would like to conduct a research entiled “ Analysis of the Performance of the Car AirConditioning system Type ET 450 with Variation of the Compressor Pressure”.The test was conducted on the car air conditioner type ET 450 with variations of suction 2.8 bar, 3 bar, 3.2 bar, 3.4bar, 3.6 bar and 3.8 bar. The data were obtained from the pressure of compressor output (P2, the temperatures in each point areT1, T2, T3, T4, the compressor rotationn is n, the strength of electrical current is I, and the volumetric flow rate. The data werethen processed and analyzed so that so that the performance of each variation of the suction could be actually and theoreticallyobtained.The findings show that the bigger the suction, the bigger the performance of the car air conditioner type ET 450 wouldbe. The theoretical coefficient of performance (COP produced was bigger than the actual COP. The optimal COP took placewhen the suction was 441.325 kPa, the actual COP was 3.513177 and the theoretical COP was 3.632062

  6. β Absorption dust concentration monitor system based on the PLC

    International Nuclear Information System (INIS)

    Lian Dexing; Zhou Xiuliang; Liu Liyan; Li Zonglun; Cao Guanghui; Mao Wanchong

    2011-01-01

    To provide an on-line automatic system for dust concentration monitor is the purpose of this design.The system based on β-ray-absorption-method,employing PLC (Programmable Logic Controller) control technology, is presented. The user input parameter setup,the data acquisition and processing, and the communication with computer can be effectively regulated using the advanced PLC control technology. It has the features of high reliability, easy operation and easy maintenance, and the ability to monitor remotely. Measurement range: 0.1-1500 mg/m 3 , Accuracy: ±9%. The structure,working principle, electric circuit and software development of the system are introduced in detail. (authors)

  7. Comparative economic assessment of the energy performance of air-conditioning within the Mexican residential sector

    Directory of Open Access Journals (Sweden)

    Ivan Oropeza-Perez

    2016-11-01

    Full Text Available This work shows a sensitivity analysis of the economic impact of different energy performances of air-conditioning within the Mexican housing sector. For this purpose, a cooling-load calculator program in function of the indoor temperature is developed. The program also calculates the electricity consumption along with the expenditure with the different residential rates of the Mexican Federal Commission of Electricity (CFE, initials in Spanish set according to the season of the year and zone of the country. After the results onto the national-scale scenario are validated with the literature, a sensitivity analysis is carried out by changing three parameters that are considered as influential on the consumption and which can be considered as energy saving strategies. With these strategies, it is found that the indoor temperature decrease due to the use of a passive cooling system is the most important characteristic to take into account followed by the coefficient of performance (COP of the air-conditioning and the increase of the comfort temperature set-point, respectively. Thereby, an economic analysis is carried out, finding an annual saving up to 770 USD within a single air-conditioned dwelling having a payback period of 3 years for using a combination of passive cooling techniques and increasing the comfort temperature set-point; or a 2 years payback period if the air-conditioning is changed by a high-efficient equipment.

  8. Human requirements in future air-conditioned environments

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    1999-01-01

    Although air-conditioning has played a positive role for economic development in warm climates, its image is globally mixed. Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from Sick Building Syndrome (SBS) symptoms...

  9. Human requirements in future air-conditioned environments

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    2001-01-01

    Although air-conditioning has played a positive role for economic development in warm climates, its image is globally mixed. Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from Sick Building Syndrome (SBS) symptoms...

  10. Human requirements in future air-conditioned environments

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    2002-01-01

    Air-conditioning of buildings has played a very positive role for economic development in warm climates. Still its image is globally mixed. Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from SBS symptoms, even...

  11. The minimum work required for air conditioning process

    International Nuclear Information System (INIS)

    Alhazmy, Majed M.

    2006-01-01

    This paper presents a theoretical analysis based on the second law of thermodynamics to estimate the minimum work required for the air conditioning process. The air conditioning process for hot and humid climates involves reducing air temperature and humidity. In the present analysis the inlet state is the state of the environment which has also been chosen as the dead state. The final state is the human thermal comfort fixed at 20 o C dry bulb temperature and 60% relative humidity. The general air conditioning process is represented by an equivalent path consisting of an isothermal dehumidification followed by a sensible cooling. An exergy analysis is performed on each process separately. Dehumidification is analyzed as a separation process of an ideal mixture of air and water vapor. The variations of the minimum work required for the air conditioning process with the ambient conditions is estimated and the ratio of the work needed for dehumidification to the total work needed to perform the entire process is presented. The effect of small variations in the final conditions on the minimum required work is evaluated. Tolerating a warmer or more humid final condition can be an easy solution to reduce the energy consumptions during critical load periods

  12. Energy Performance and Optimal Control of Air-conditioned Buildings Integrated with Phase Change Materials

    Science.gov (United States)

    Zhu, Na

    This thesis presents an overview of the previous research work on dynamic characteristics and energy performance of buildings due to the integration of PCMs. The research work on dynamic characteristics and energy performance of buildings using PCMs both with and without air-conditioning is reviewed. Since the particular interest in using PCMs for free cooling and peak load shifting, specific research efforts on both subjects are reviewed separately. A simplified physical dynamic model of building structures integrated with SSPCM (shaped-stabilized phase change material) is developed and validated in this study. The simplified physical model represents the wall by 3 resistances and 2 capacitances and the PCM layer by 4 resistances and 2 capacitances respectively while the key issue is the parameter identification of the model. This thesis also presents the studies on the thermodynamic characteristics of buildings enhanced by PCM and on the investigation of the impacts of PCM on the building cooling load and peak cooling demand at different climates and seasons as well as the optimal operation and control strategies to reduce the energy consumption and energy cost by reducing the air-conditioning energy consumption and peak load. An office building floor with typical variable air volume (VAV) air-conditioning system is used and simulated as the reference building in the comparison study. The envelopes of the studied building are further enhanced by integrating the PCM layers. The building system is tested in two selected cities of typical climates in China including Hong Kong and Beijing. The cold charge and discharge processes, the operation and control strategies of night ventilation and the air temperature set-point reset strategy for minimizing the energy consumption and electricity cost are studied. This thesis presents the simulation test platform, the test results on the cold storage and discharge processes, the air-conditioning energy consumption and demand

  13. The Future of Air Conditioning for Buildings - Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Young, J. [Navigant Consulting Inc., Burlington, MA (United States); Fuhrman, J. [Navigant Consulting Inc., Burlington, MA (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-07-01

    The Building Technologies Office (BTO), within the U.S. Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy, works with researchers and industry to develop and deploy technologies that can substantially reduce energy consumption and greenhouse gas (GHG) emissions in residential and commercial buildings. Air conditioning (A/C) systems in buildings contribute to GHG emissions both directly through refrigerant emissions, as well as indirectly through fossil fuel combustion for power generation. BTO promotes pre-competitive research and development (R&D) on next-generation HVAC technologies that support the phase down of hydrofluorocarbon (HFC) production and consumption, as well as cost-effective energy efficiency improvements. Over the past several decades, product costs and lifecycle cooling costs have declined substantially in many global markets due to improved, higher-volume manufacturing and higher energy efficiency driven by R&D investments and efficiency policies including minimum efficiency standards and labeling programs.1 This report characterizes the current landscape and trends in the global A/C market, including discussion of both direct and indirect climate impacts, and potential global warming impacts from growing global A/C usage. The report also documents solutions that can help achieve international goals for energy efficiency and GHG emissions reductions. The solutions include pathways related to low-global warming potential2 (GWP) refrigerants, energy efficiency innovations, long-term R&D initiatives, and regulatory actions. DOE provides, with this report, a fact-based vision for the future of A/C use around the world. DOE intends for this vision to reflect a broad and balanced aggregation of perspectives. DOE brings together this content in an effort to support dialogue within the international community and help keep key facts and objectives at the forefront among the many important discussions.

  14. The Histoty of Ventilation and Air Conditioning is CERN Up to Date with the latest Technological Developments?

    CERN Document Server

    Kühnl-Kinel, J

    2000-01-01

    The invention of ventilation cannot be ascribed to a certain date. It started with simple aeration when man brought fire into his abode and continued through different stages including air cooling using ice to finally arrive at the time when ventilation and air conditioning has become an essential part of our life and plays an important role in human evolution. This paper presents the history of ventilation and air conditioning, explains the key constraints over the centuries, and shows its influence on everyday life. Some examples of previous air-conditioning plants are described and different approaches to the way of calculation of ventilation systems discussed. It gives an overview of the Heating, Ventilation and Air Conditioning (HVAC) installations at CERN and points out their particularities. It also compares them with the latest technological developments in the field as well as showing the new trends that are being applied at CERN.

  15. Energetically optimized air conditioning systems for rooms with high internal heat load and enhanced safety requirements, e.g. server rooms or control rooms of the communications industry; Energetisch optimierte Klimasysteme fuer Raeume mit hoher innerer Waermelast und erhoehten Sicherheitsanforderungen, wie z.B. Serverraeumen, Controlrooms der Kommunikationsindustrie

    Energy Technology Data Exchange (ETDEWEB)

    Bertuleit, R. [Bertuleit und Boekenkroeger GmbH, Hameln (Germany)

    2003-07-01

    High safety requirements and high constant internal heat loads require sophisticated air conditioners. As computer capacities are commonly divided up into several rooms for safety reasons, a central air conditioning unit is not the optimal solution, so free cooling modules and special computer air conditioning cabinets are used. Design improvements and a consequent raising of the room temperature helped to reduce the 100 percent free cooling operation temperature from 2 to 14 degrees centigrade. This is the basis for energetic optimisation. Modern blowers helped to reduce the annual energy consumption of the secondary aggregates. Optimisation of the system and mode of operation reduced the annual energy consumption from 441,000 kWh to 128,000 kWh per 100 kW of refrigeration power. A further improvement of the energy balance was achieved by installing a water-to-water heat pump using the waste heat of the air-conditioned rooms. The life cycle cost (10 years at an assumed electricity rate of 10 cent per kWh) are reduced from 666,000 EUR to 411,000 EUR per 100 kW of installed refrigeration capacity. In spite of the higher investment cost, energy-optimised systems will result in an overall cost reduction. (orig.) [German] Hohe sicherheitstechnische Anforderungen und konstante innere Waermelasten stellen hohe Anforderungen an die Ausfuehrung der klimatechnischen Systeme. Aus Sicherheitsgruenden erfolgt eine Aufteilung der Rechnerkapazitaeten auf mehrere Raeume. Somit ist der Einsatz eines zentralen Klimasystems nicht sinnvoll. Zum Einsatz kommen Freikuehlmodule und spezielle EDV-Klimaschraenke. Durch konstruktive Verbesserungen und konsequente Anhebung der Raumtemperaturen konnte der 100% Freikuehlbetrieb von + 2 C auf +14 C angehoben werden und damit die Basis fuer energetische Optimierung geschaffen werden. Durch den Einsatz moderner Ventilationssysteme konnte der Jahresenergieverbrauch der Nebenaggregate wesentlich gesenkt werden. Die System- und Nutzungsoptimierung

  16. Air-conditioning and antibiotics: Demand management insights from problematic health and household cooling practices

    International Nuclear Information System (INIS)

    Nicholls, Larissa; Strengers, Yolande

    2014-01-01

    Air-conditioners and antibiotics are two technologies that have both been traditionally framed around individual health and comfort needs, despite aspects of their use contributing to social health problems. The imprudent use of antibiotics is threatening the capacity of the healthcare system internationally. Similarly, in Australia the increasing reliance on air-conditioning to maintain thermal comfort is contributing to rising peak demand and electricity prices, and is placing an inequitable health and financial burden on vulnerable heat-stressed households. This paper analyses policy responses to these problems through the lens of social practice theory. In the health sector, campaigns are attempting to emphasise the social health implications of antibiotic use. In considering this approach in relation to the problem of air-conditioned cooling and how to change the ways in which people keep cool during peak times, our analysis draws on interviews with 80 Australian households. We find that the problem of peak electricity demand may be reduced through attention to the social health implications of air-conditioned cooling on very hot days. We conclude that social practice theory offers a fruitful analytical route for identifying new avenues for research and informing policy responses to emerging health and environmental problems. - Highlights: • Over-use of antibiotics and air-conditioning has social health implications. • Focusing on financial incentives limits the potential of demand management programs. • Explaining peak demand to households shifts the meanings of cooling practices. • Emphasising the social health implications of antibiotics and air-conditioning may resurrect alternative practices. • Analysing policy with social practice theory offers insights into policy approaches

  17. Retrofitting Inefficient Rooftop Air-Conditioning Units Reduces U.S. Navy Energy Use (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-04-01

    As part of the U.S. Navy's overall energy strategy, the National Renewable Energy Laboratory (NREL) partnered with the Naval Facilities Engineering Command (NAVFAC) to demonstrate market-ready energy efficiency measures, renewable energy generation, and energy systems integration. One such technology - retrofitting rooftop air-conditioning units with an advanced rooftop control system - was identified as a promising source for reducing energy use and costs, and can contribute to increasing energy security.

  18. Air conditioning with methane: Efficiency and economics optimization parameters

    International Nuclear Information System (INIS)

    Mastrullo, R.; Sasso, M.; Sibilio, S.; Vanoli, R.

    1992-01-01

    This paper presents an efficiency and economics evaluation method for methane fired cooling systems. Focus is on direct flame two staged absorption systems and alternative engine driven compressor sets. Comparisons are made with conventional vapour compression plants powered by electricity supplied by the national grid. A first and second law based thermodynamics analysis is made in which fuel use coefficients and exergy yields are determined. The economics analysis establishes annual energy savings, unit cooling energy production costs, payback periods and economics/efficiency optimization curves useful for preliminary feasibility studies

  19. Energy and exergy analyses of the diffusion absorption refrigeration system

    International Nuclear Information System (INIS)

    Yıldız, Abdullah; Ersöz, Mustafa Ali

    2013-01-01

    This paper describes the thermodynamic analyses of a DAR (diffusio