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Sample records for additional heating systems

  1. Thermal Efficiency of Power Module “Boiler with Solar Collectors as Additional Heat Source” For Combined Heat Supply System

    Denysova A.E.; Mazurenko A.S.; Denysova A.S.

    2015-01-01

    The purpose of work is to increase the efficiency of the combined heat supply system with solar collectors as additional thermal generators. In order to optimize the parameters of combined heat supply system the mathematical modeling of thermal processes in multi module solar collectors as additional thermal generators for preheating of the water for boiler have been done. The method of calculation of multi-module solar collectors working with forced circulation for various configurations of ...

  2. Influence of Dispersed Heat-Resistant Additives on Ignition and Combustion of Heterogeneous Systems

    Arkhipov V.A.

    2015-01-01

    Full Text Available The results of experimental studies of the effect of dispersion of heat-resistant additives powders on ignition and combustion of heterogeneous condensed systems. The method of measuring the time delay ignition conductive and radiant heating, and combustion rate at atmospheric pressure. The effect of additives powders of boron, silicon and titanium dioxide on the ignition and combustion of heterogeneous condensed systems.

  3. Thermal Efficiency of Power Module “Boiler with Solar Collectors as Additional Heat Source” For Combined Heat Supply System

    Denysova A.E.

    2015-04-01

    Full Text Available The purpose of work is to increase the efficiency of the combined heat supply system with solar collectors as additional thermal generators. In order to optimize the parameters of combined heat supply system the mathematical modeling of thermal processes in multi module solar collectors as additional thermal generators for preheating of the water for boiler have been done. The method of calculation of multi-module solar collectors working with forced circulation for various configurations of hydraulic connection of solar collector modules as the new result of our work have been proposed. The results of numerical simulation of thermal efficiency of solar heat source for boiler of combined heat supply system with the account of design features of the circuit; regime parameters of thermal generators that allow establishing rational conditions of its functioning have been worked out. The conditions of functioning that provide required temperature of heat carrier incoming to boiler and value of flow rate at which the slippage of heat carrier is not possible for different hydraulic circuits of solar modules have been established.

  4. Proper use of sludge-control additives in residential heating oil systems

    Tatnall, R.E. [MIC Associates, Inc., Chadds Ford, PA (United States)

    1995-04-01

    Discussed are various aspects of heating oil `sludge`: How it forms, typical problems it causes, how sludge-control additives work, what should be expected of them, and what happens in a contaminated system when such additives are used. Test results from laboratory and field experiments demonstrate that performance of commercially available additives varies greatly. The concept of `end-of-the-line` treatment is described and compared with bulk fuel treatment. A procedure is described whereby a retailer can test additives himself, and thus determine just what those additives will or will not do for his business. Finally, the economics of an effective treatment program are outlined.

  5. Electron-beam welding of the grill flanges of the FTU additional heating system

    The research and development program of the fusion sector of ENEA (Italian Agency for New Technologies, Energy and Environment) Frascati center is mainly based on experiments on the Frascati Tokamak Upgrade (FTU) machine. The FTU is a medium-high magnetic field (8 T) tokamak with a radio-frequency (RF) additional heating system (8 MW, 8 GHz) that can heat the plasma to temperatures of fusionistic interest. The RF power is coupled to the plasma by a coupling structure consisting of three grills, each formed of an array of waveguides welded at the terminal flanges by an electron-beam technique. This solution allows highly accurate dimensions and optimum clean-surface conditions of the welded copper joints

  6. Additional adiabatic heating of plasma

    A theoretical possibility of a plasma additional adiabatic heating up to temperatures needed for the begin of D-T thermonuclear fusion reaction, has been found on the base of the polyenergetic conjugation expression, developed in the Thermodynamics of Accumulation Processes. TAP is a branch of the non-equilibrium thermodynamics. The thermodynamics of irreversible processes is another branch of the entire non-equilibrium thermodynamics. TAP deals with the phenomena associated with the introduction, conversion and accumulation of mass or energy or both in the affected, open or closed systems. (author) 2 refs

  7. Effect of Cu addition and heat treatment self-propagating high temperature synthesis reaction in Al-Ti-C system

    Li Y.X.; Hu J.D.; Liu Y.H.; Guo Z.X.

    2008-01-01

    Effect of Cu addition and heat treatment on the self-propagating high temperature synthesis reaction have been investigated. The results show that Cu reacts with Al to form Al2Cu phase. With the addition of Cu, the combustion temperature of the system decreases and the porosity of the products is reduced, the size of TiC particulate decreases in the SHS reaction products. Specially, when heat treatment is carried out for the sintering products at 800 ◦C, the rigid framework (sintering neck) b...

  8. Evaluation of hydrazine as an additive to provide reducing condition in the main heat transport system of AHWR

    Hydrogen is known to be injected in boiling water reactors to mitigate stress corrosion cracking (SCC) due to the oxidizing environment prevailing in the reactor coolant system. Further this technique has been modified by addition of noble metals such as Pt, Ir so that the required ECP can be achieved by injecting a lower concentration of hydrogen. All the boiling water reactors are pot type reactors. Unlike BWRs, the Advanced Heavy Water Reactor (AHWR) is a boiling tube type reactor. Here, boiling takes place in the tube and the coolant exits the core with 18 % steam. The steam containing water exits the core through tail pipes connected to each fuel channel. The material of construction of most of the AHWR main coolant system components is stainless steel. Hence, the possibility of stress corrosion cracking of stainless steel components can not be ruled out if oxidizing chemistry conditions prevail in the coolant. Addition of hydrogen and hydrogen with noble metal may not be effective in controlling the radiolytic generation of oxygen/hydrogen peroxide under the two phase conditions prevailing in the fuel channels (tubes) of the core. Hence, the feasibility of using hydrazine to provide reducing condition to the main heat transport system of AHWR was studied. Computation on the generation of oxidizing species (O2 and H2O2) and their distribution in steam and water phase were made. The difference in the distribution behavior of hydrogen and hydrazine under AHWR condition is explained in the paper. Analytical methods have been standardized to study the distribution of hydrazine, ammonia, oxygen and hydrogen peroxide and tested by carrying out radiolysis of water containing hydrazine etc. Experiments were also carried out in the High Temperature and High Pressure (HTHP) system at WSCD to study the thermal stability of hydrazine and to evaluate its effect on the redox potential and corrosion potential of stainless steel under the simulated AHWR temperature conditions

  9. Additively Manufactured Propulsion System

    Dushku, Matthew; Mueller, Paul

    2012-01-01

    New high-performance, carbon-fiber reinforced polymer material allows additive manufacturing to produce pressure vessels capable of high pressures (thousands of pounds per square inch). This advancement in turn allows integral hybrid propulsion which is revolutionary for both CubeSats and additively-manufactured spacecraft. Hybrid propulsion offers simplicity as compared to bipropellant liquid propulsion, significantly better safety compared to solid or monopropellant hydrazine propulsion, an...

  10. Ground Source Heat Pump in Heating System with Electronics Monitoring

    NEAMŢU Ovidiu

    2013-10-01

    Full Text Available The monitoring system is implemented for a ground coupled heat pump in heating/ system. The borehole heat exchangers – which are 150 m long - are filled with a mixture of water and ethilene glycol calledbrine. Metering and monitoring energy consumption is achieved for: heat pump, circulation pumps, additional electrical heating, hot air ventilation systems, control systems with sensors: analog and smart sensors. Instantaneous values are stored in a local computer.

  11. Additive Manufacturing of Heat Pipe Wicks Project

    National Aeronautics and Space Administration — Wick properties are often the limiting factor in a heat pipe design. Current technology uses conventional sintering of metal powders, screen wick, or grooves to...

  12. Additional heating power supplies: Design concept and first operation

    Two additional heating methods are used in JET, e.g. the Neutral Injection (NI heating) and the Ion Cyclotron Resonance Heating (RF Heating). In the RF heating, 10 generators each deliver 3MW to their antenna; for the NI heating 16 ion sources each delivering 4.8MW ion beam are installed. In order to minimize the internal dissipation in the generator and hence to obtain the maximum output power of the RF generators under the varying load conditions given by the plasma, the high voltage on the anode of the tetrode is varied. This is one of the main features of the power supply. The requirements for the NI power supply are different to the ones for the RF power supply. The accelerating grid (G1) power supply has to be very stable and must be able to switch off in 10 microsec in case of a breakdown in the accelerating structure and re-apply within 50 ms. Both these functions, voltage regulation and switching on and off are performed by a high power tetrode (protection system). In addition to the accelerating grid power supply, other power supplies (Aux PS) are necessary. They are the arc power supply, the filament power supply, the suppression grid (G3) power supply, the gradient grid (G2) power supply and the bending magnet power supply

  13. Heating systems for heating subsurface formations

    Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  14. Heat rejection system

    Smith, Gregory C.; Tokarz, Richard D.; Parry, Jr., Harvey L.; Braun, Daniel J.

    1980-01-01

    A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

  15. 40 CFR 97.76 - Additional requirements to provide heat input data.

    2010-07-01

    ... heat input data. 97.76 Section 97.76 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Monitoring and Reporting § 97.76 Additional requirements to provide heat input data. The owner or operator of... a flow system shall also monitor and report heat input rate at the unit level using the...

  16. Waste heat recovery system

    Full text: The Konzen in-house designed anaerobic digester system for the POME (Palm Oil Mill Effluent) treatment process is one of the registered Clean Development Mechanism (CDM) projects in Malaysia. It is an organic wastewater treatment process which achieves excellent co-benefits objectives through the prevention of water pollution and reduction of greenhouse gas emissions, which is estimated to be 40,000 to 50,000 t-CO2 per year. The anaerobic digester was designed in mesophile mode with temperature ranging from 37 degree Celsius to 45 degree Celsius. A microorganisms growth is optimum under moderately warm temperature conditions. The operating temperature of the anaerobic digester needs to be maintained constantly. There are two waste heat recovery systems designed to make the treatment process self-sustaining. The heat recovered will be utilised as a clean energy source to heat up the anaerobic digester indirectly. The first design for the waste heat recovery system utilises heat generated from the flue gas of the biogas flaring system. A stainless steel water tank with an internal water layer is installed at the top level of the flare stack. The circulating water is heated by the methane enriched biogas combustion process. The second design utilizes heat generated during the compression process for the biogas compressor operation. The compressed biogas needs to be cooled before being recycled back into the digester tank for mixing purposes. Both the waste heat recovery systems use a design which applies a common water circulation loop and hot water tank to effectively become a closed loop. The hot water tank will perform both storage and temperature buffer functions. The hot water is then used to heat up recycled sludge from 30 degree Celsius to 45 degree Celsius with the maximum temperature setting at 50 degree Celsius. The recycled sludge line temperature will be measured and monitored by a temperature sensor and transmitter, which will activate the

  17. Heat Pipe Systems

    1993-01-01

    The heat pipe was developed to alternately cool and heat without using energy or any moving parts. It enables non-rotating spacecraft to maintain a constant temperature when the surface exposed to the Sun is excessively hot and the non Sun-facing side is very cold. Several organizations, such as Tropic-Kool Engineering Corporation, joined NASA in a subsequent program to refine and commercialize the technology. Heat pipes have been installed in fast food restaurants in areas where humid conditions cause materials to deteriorate quickly. Moisture removal was increased by 30 percent in a Clearwater, FL Burger King after heat pipes were installed. Relative humidity and power consumption were also reduced significantly. Similar results were recorded by Taco Bell, which now specifies heat pipe systems in new restaurants in the Southeast.

  18. Boiler efficiency increase by building-in the additional heating surfaces (heat utilizer)

    Rationalization of the energy consumption is of general social interest, and therefore it is necessary to undertake all measures that will increase the degree of utilization of the power plants. One way of rationalization in thermal energy production is reducing the temperature of flue gases by building-in the additional heating surfaces in boiler flue channel. The results and analyses of several years measuring of boiler parameters, with built-in heat exchanger, by system of the remote control and data acquisition are presented in this paper. The particular review is given for fuel saving and time of the investment payback. Working on this problem in cooperation with the Institute for energetic and process techniques of the Faculty of Technical Sciences in Novi Sad, hot water boiler of 9.3 MW power is chosen for concrete checking of the previous investigations. The feasibility of building-in additional water heater (utilizer) in flue channel of the existing hot water boiler was established in the paper. From the table and presented diagrams obtained by measuring, and on the basis of tech-economic analysis it can be concluded that there is the complete feasibility of building-in the additional heat exchanger. The building-in costs are very quickly paid back. The efficiency of water reheater in utmost extent depends on the inlet water temperature as well, and it is higher as the inlet water temperature is lower, and even the condensation of flue gases is desirable. At boilers that use natural gas as the fuel there is no danger of low temperature corrosion, as natural gas doesn't contain sulphur. The experience during the natural gas fired boiler exploitation shows that steam condensation from flue gases does not influence the heating surface corrosion in great extent, as the condensate is almost neutral. Due to the mentioned reasons it is desirable for boilers that use natural gas to have as large as possible heating surfaces, which can be obtained at the existing

  19. Additive manufacturing of a compact flat-panel cryogenic gas-gap heat switch

    Vanapalli, S.; Vermeer, C.H.; Tirolien, T.

    2016-01-01

    State-of-the-art heat switches are only rarely employed in thermal system architectures, since they are rather bulky and have a limited thermal performance (expressed as the heat transfer ratio between the "On" and "Off" state). Using selective laser melting additive manufacturing technology, also k

  20. Low-cost Electromagnetic Heating Technology for Polymer Extrusion-based Additive Manufacturing

    Carter, William G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rios, Orlando [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Akers, Ronald R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Morrison, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-07

    To improve the flow of materials used in in polymer additive manufacturing, ORNL and Ajax Tocco created an induction system for heating fused deposition modeling (FDM) nozzles used in polymer additive manufacturing. The system is capable of reaching a temperature of 230 C, a typical nozzle temperature for extruding ABS polymers, in 17 seconds. A prototype system was built at ORNL and sent to Ajax Tocco who analyzed the system and created a finalized power supply. The induction system was mounted to a PrintSpace Altair desktop printer and used to create several test parts similar in quality to those created using a resistive heated nozzle.

  1. A new waste heat district heating system with combined heat and power (CHP) based on ejector heat exchangers and absorption heat pumps

    A new waste heat district heating system with CHP based on ejector heat exchangers and absorption heat pumps (DH-EHE) is presented to decrease heating energy consumption of existing CHP systems by recovering waste heat of exhausted steam from a steam turbine, which could also increase heat transmission capacity of the primary heating network (PHN) by decreasing temperature of the return water of existing PHN. A new ejector heat exchanger based on ejector refrigeration cycle is invented to decrease temperature of the return water of PHN to 30 °C under the designed case. DH-EHE is analyzed in terms of laws of thermodynamics and economics. Compared to conventional district heating systems with CHP (CDH), DH-EHE can decrease consumption of steam extracted from a steam turbine by 41.4% and increase heat transmission capacity of the existing PHN by 66.7% without changing the flow rate of circulating water. The heating cost of DH-EHE is 8.62 ¥/GJ less than that of CDH. Compared to CDH, the recovery period of additional investment of DH-EHE is about two years. DH-EHE shows better economic and environmental benefits, which is promising for both district heating systems for long-distance heat transmission and waste heat district heating systems. - Highlights: • Heating capacity of this new heating system increases by 41% by waste heat recovery. • Temperature of return water of the primary heating network can be reduced to 30 °C. • Heating cost of new heating system is 8.62¥/GJ less than that of conventional one. • The recovery period of additional investment of new heating system is about 2 years. • This new heating system shows better economic and environmental benefits

  2. Calculation of additional heat loss through heat-conducting inclusions (on the example of window reveal

    I.S. Safin

    2010-10-01

    Full Text Available To solve the problem of improving the energy efficiency in buildings the materials with low thermal conductivity are used. The constructive difficulty of the modern walling and the heterogeneity of materials must be carefully calculated in designing, constructing and operating of buildings.The method of thermotechnical calculation based on the determination of the additional heat loss through heat-conducting inclusions (on the example of the jamb construction unit has been considered in this work. The determination of the value of additional heat flows is carried out by calculating the temperature fields.The results show that the value of the additional heat flows depends not only on the constructive solution of nodes, but also on the architectural design of buildings. That’s why it is necessary to define a reduced thermal resistance for each building’s facade. The proportion of heat loss through consideration of heat-conducting inclusion of major heat loss, calculated by design coats, can reach more than 20%.

  3. Recommender system for nuitrition additives

    Koštrun, Simon

    2016-01-01

    Food supplements are becoming more and more common every day. The question arises, how to help the user in the selection of them. The goal is to create a web application, which returns to user the most appropriate food supplements, how he or she should take them, what to avoid, where to buy, etc. For implementation, we used validated and extended web technologies. For users and system administrators we use HTML5, CSS and JavaScript, while PHP and MySQL perform the background work. For each us...

  4. Development of heating system

    The detailed designs and development of components of NBI, RF, ECH, and LHCD heating and current drive system have been performed. The prototype ion source for the KSTAR NBI system and the beam line components such as calorimeter, neutralizer, bending magnet, and ion dump had been developed. The power supplies for the stable beam of 120 kV and 65 A including acceleration power supply, deceleration power supply, arc power supply, and filament power supply have been developed. Finally a KSATR NB test facility has been completed at KAERI to test and upgrade the ion source and the beam line components. The RF system is under development. Antenna has been fabricated and tested. Transmission components (vacuum feedthrough, impedance matching and water-cooled transmission line) for transmitting MW level of power have been developed. For transmitter, we optimized performance of 100kW transmitter and completed the fabrication of 300 kW transmitter. We will finalize the procurement specification of 2 MW transmitter system in the third phase. The detailed design of a 500 kW, 84 GHz ECH system has been completed. The gyrotron has been fabricated and successfully tested at Communications and Power Industries(CPI), USA. It is delivered to POSTECH, and under short pulse conditioning test with a pulse modulator operated at 20 μs with 60 Hz repetition rate and a acceleration power supply (APS). The ECH transmission line components are being purchased from General Atomics (GA), USA. The LH frequency of the 2.0 MW LHCD system is chosen to 5.0 GHz for extending the density limit condition. The LHCD system is under design process. The basic design of the 5.0 GHz LHCD launcher (coupler) has been finished using the HFSS and ANSYS programs.

  5. KSTAR RF heating system development

    Kwak, J. G.; Kim, S. K.; Hwang, C. K. (and others)

    2007-10-15

    Design, high-voltage test, and installation of 6 MW ICRF heating system for KSTAR is completed. The antenna demonstrated satisfactory standoff at high voltages up to 41 kV for 300 sec. The result indicates good power handling capabilities of the antenna as high as 10 MW/m2. This power density is equivalent to RF power coupling of 6 MW into a 4 {omega}/m target plasma, and is typical of advanced tokamak heating scenarios. In addition, vacuum feed through, DC break, and liquid stub developed for 300 sec operation are installed, as well as a 2 MW, 30-60MHz transmitter. The transmitter successfully produced output powers of 600 kW continuously, 1.5{approx}1.8 MW for 300 sec, and 2 MW for 100 msec or shorter pulses. A realtime control system based on DSP and EPICS is developed, installed, and tested on the ICRF system. Initial results from feasibility study indicate that the present antenna and the transmission lines could allow load-resilient operation on KSTAR. Until the KSTAR tokamak start to produce plasmas in 2008, however, hands-on operational experiences are obtained from participating in ICRF heating experiments at ASDEX and DIII-D tokamaks arranged through international cooperation.

  6. Studies Concerning Heat-Resisting Additives for Bitumens

    Livia Groll

    2008-01-01

    Full Text Available The improvement of causeway’s bitumen adhesiveness is becoming a current practice in our country, especially when is used acid (siliceous aggregate. One of the most important properties of bitumen is its adhesiveness to aggregate, and this property determine the using of bitumen in causeways area. Usually the adhesiveness is defined as the capacity of a binder to cover an aggregate without dispersing itself when touching the water or the traffic aggressions. Therefore, the adhesiveness additives are products that improve the adhesiveness of the bitumen to a certain aggregate. The used additives – ADETEN type (A01 and A03 have a high stocking stability, a low toxicity degree toward the amine, diamine, polyamine-based additives and are liquid products perfectly compatible with all bitumens and easy to use, in comparison to the paste or solid additives, which must be made liquid to be used. But a very important condition, which must be fulfilled by these promoters is the heat-resisting condition.

  7. Operation of Geothermal Heat System in The Hague, Netherlands

    Geothermal Heat system The Hague needs a provision in the shape of a geothermal heat system for additional heat supply to approximately 4000 dwellings in the Southwest of The Hague. Some interested persons and residents have questions about the operation of the system, the linkage to the source of geothermal heat, the need for an auxiliary heat boiler, the emission, the operating hours, the noise and the plume formation. This memo contains an explanation of the various components of the geothermal heat plant.

  8. Heat pipe cooling system with sensible heat sink

    Silverstein, Calvin C.

    1988-01-01

    A heat pipe cooling system which employs a sensible heat sink is discussed. With this type of system, incident aerodynamic heat is transported via a heat pipe from the stagnation region to the heat sink and absorbed by raising the temperature of the heat sink material. The use of a sensible heat sink can be advantageous for situations where the total mission heat load is limited, as it is during re-entry, and a suitable radiation sink is not available.

  9. Preliminary design package for solar heating and cooling systems

    1978-01-01

    Summarized preliminary design information on activities associated with the development, delivery and support of solar heating and cooling systems is given. These systems are for single family dwellings and commercial applications. The heating/cooling system use a reversible vapor compression heat pump that is driven in the cooling mode by a Rankine power loop, and in the heating mode by a variable speed electric motor. The heating/cooling systems differ from the heating-only systems in the arrangement of the heat pump subsystem and the addition of a cooling tower to provide the heat sink for cooling mode operation.

  10. Solar Heating System with Building-Integrated Heat Storage

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating, and due to storage. Heat demand is reduced due to direct solar heating, due to storage and due to lower heat losses through the ground. In theory, by running the system flow backwards through the sand storage, active heating...... can be achieved.The objective of the report is to present results from measured system evaluation andcalculations and to give guidelines for the design of such solar heating systems with building integrated sand storage. The report is aimed to non-technicians. In another report R-006 the main results...

  11. Heat exchanger demonstration expert system

    Bagby, D. G.; Cormier, R. A.

    1988-05-01

    A real-time expert system intended for detecting and diagnosing faults in a 20 kW microwave transmitter heat exchanger is described. The expert system was developed on a LISP machine, Incorporated (LMI), Lambda Plus computer using Process Intelligent Control (PICON) software. The Heat Exhanger Expert System was tested and debugged. Future applications and extensions of the expert system to transmitters, masers, and antenna subassemblies are discussed.

  12. Heat Pumps in CHP Systems

    Ommen, Torben Schmidt

    capacity constraints limit the efficient operation of the CHP plants. Heat pumps (HPs) can be used to decouple such constraints, but current state of the art are not competitive all things considered. Methods to improve the high energy efficiency are required to match the politically agreed carbon emission......In the current Danish energy system, the majority of electricity and heat is produced in combined heat and power (CHP) plants. With increasing shares of intermittent renewable power production, it becomes a challenging task to match power and heat production to its demand curves, as production...... goals. The presented study investigates the possible introduction of HPs from both a thermodynamic and a system/operation management perspective, in order to find optimal integration schemes in both current and future energy scenarios. Five generic configurations of HPs in district heating (DH) systems...

  13. Boise geothermal district heating system

    Hanson, P.J.

    1985-10-01

    This document describes the Boise geothermal district heating project from preliminary feasibility studies completed in 1979 to a fully operational system by 1983. The report includes information about the two local governments that participated in the project - the City of Boise, Idaho and the Boise Warm Springs Water District. It also discusses the federal funding sources; the financial studies; the feasibility studies conducted; the general system planning and design; design of detailed system components; the legal issues involved in production; geological analysis of the resource area; distribution and disposal; the program to market system services; and the methods of retrofitting buildings to use geothermal hot water for space heating. Technically this report describes the Boise City district heating system based on 170/sup 0/F water, a 4000 gpm production system, a 41,000 foot pipeline system, and system economies. Comparable data are also provided for the Boise Warm Springs Water District. 62 figs., 31 tabs.

  14. Supply temperature control concepts in heat pump heating systems

    Huchtemann, Kristian

    2015-01-01

    In recent years, electrically driven compression heat pumps have come to be widely used for the heating of buildings. Their efficiency strongly depends on the temperature lift which is influenced by the supply temperature of the heat sink. When used with radiator heating systems it is challenging to operate heat pumps efficiently because high supply temperatures are required. Therefore, in order to efficiently operate heat pumps, this work analyses advanced control concepts for heatpump heati...

  15. Caustic addition system operability test procedure

    This test procedure provides instructions for performing operational testing of the major components of the 241-AN-107 Caustic Addition System by WHC and Kaiser personnel at the Rotating Equipment Shop run-in pit (Bldg. 272E)

  16. Estimation of Heating Device‘s Convective Heat Transfer of Heat Supply Systems with Rotational Heat Generator

    A. Nesenchuk

    2014-09-01

    Full Text Available In this article, on the base of heat exchange analysis in heat supply systems with rotational heat generator, a calculated formula for estimation of heat transfer from the surface of heating device is obtained, taking into account its probability (random orientation in space. It is shown the most probable position of heating devices in heating system of mobile object.

  17. Estimation of Heating Device‘s Convective Heat Transfer of Heat Supply Systems with Rotational Heat Generator

    A. Nesenchuk; I. Iokova; T. Rizova; P. Lasij; D. Shklovchik; Z. Aidarova

    2014-01-01

    In this article, on the base of heat exchange analysis in heat supply systems with rotational heat generator, a calculated formula for estimation of heat transfer from the surface of heating device is obtained, taking into account its probability (random) orientation in space. It is shown the most probable position of heating devices in heating system of mobile object.

  18. Prototype solar heating and combined heating cooling systems

    1978-01-01

    The design and development of eight prototype solar heating and combined heating and cooling systems is discussed. The program management and systems engineering are reported, and operational test sites are identified.

  19. CAREM-25: Residual heat removal system

    The objective of this work was the definition and consolidation of the residual heat removal system for the CAREM 25 reactor. The function of this system is cool down the primary circuit, removing the core decay heat from hot stand-by to cold shutdown and during refueling. In addition, this system heats the primary water from the cold shutdown condition to hot stand-by condition during the reactor start up previous to criticality. The system has been designed according to the requirements of the standards: ANSI/ANS 51.1 'Nuclear safety criteria for the design of stationary PWR plants'; ANSI/ANS 58.11 'Design criteria for safe shutdown following selected design basis events in light water reactors' and ANSI/ANS 58.9 'Single failure criteria for light water reactor safety-related fluid systems'. The suggested design fulfills the required functions and design criteria standards. (author)

  20. Solar heating systems. Part 1

    Results of a survey, undertaken by a Danish specialist firm, concerning solar heating systems. The main aim of the analysis was to build up a basis for the choice of a strategy for a campaign for marketing these systems. The survey was founded on telephone interviews with ca. 500 house-owners located throughout the country. Questions posed related to the individuals' current mode of space heating and future wishes in this respect, the amount of acquired information on the subject and the nature of considerations regarding acquisition, the level of information acquired and the choice of information sources, the amount of realistic information on prices, possible subsidies and oil savings related to the supplementary use of solar energy, the name of the relevant commercial supplier and attitudes to a number of aspects connected with the solar heating systems. The results are presented by means of a short explanatory text and a large volume of data. Generally speaking, it is concluded that most people in Denmark are reasonably well-informed on solar heating systems, and that they take environmental considerations seriously. Differences of opinion were related to the fact that some felt that the system itself, placed on roofs, was ugly and could perhaps appear pretentious. Only 5% of the interviewed persons had actually been in contact with an installator, although the majority had a positive attitude towards solar heating systems. (AB)

  1. Competitive solar heating systems for residential buildings

    Furbo, Simon; Thür, Alexander; Fiedler, Frank;

    2005-01-01

    The paper describes the ongoing research project “Competitive solar heating systems for residential buildings”. The aim of the project is to develop competitive solar combisystems which are attractive to buyers. The solar combisystems must be attractive compared to traditional energy systems, both...... onto the market. In Denmark and Norway the focus is on solar heating/natural gas systems, and in Sweden and Latvia the focus is on solar heating/pellet systems. Additionally, Lund Institute of Technology and University of Oslo are studying solar collectors of various types being integrated into the......, are the universities: Technical University of Denmark, Dalarna University, University of Oslo, Riga Technical University and Lund Institute of Technology, as well as the companies: Metro Therm A/S (Denmark), Velux A/S (Denmark), Solentek AB (Sweden) and SolarNor (Norway). The project consists of a...

  2. WASTE HEAT RECOVERY IN HEAT PUMP SYSTEMS: SOLUTION TO REDUCE GLOBAL WARMING

    Y. Baradey

    2015-11-01

    Full Text Available Energy conversion technologies, where waste heat recovery systems are included, have received significant attention in recent years due to reasons that include depletion of fossil fuel, increasing oil prices, changes in climatic conditions, and global warming. For low temperature applications, there are many sources of thermal waste heat, and several recovery systems and potential useful applications have been proposed by researchers [1-4]. In addition, many types of equipment are used to recover waste thermal energy from different systems at low, medium, and high temperature applications, such as heat exchangers, waste heat recovery boiler, thermo-electric generators, and recuperators. In this paper, the focus is on waste heat recovery from air conditioners, and an efficient application of these energy resources. Integration of solar energy with heat pump technologies and major factors that affect the feasibility of heat recovery systems have been studied and reviewed as well. KEYWORDS: waste heat recovery; heat pump.

  3. Loop heat pipes - highly efficient heat-transfer devices for systems of sun heat supply

    Maydanik, Yu. [Ural Branch of the Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of Thermophysics

    2004-07-01

    Loop heat pipes (LHPs) are hermetic heat-transfer devices operating on a closed evaporation-condensation cycle with the use of capillary pressure for pumping the working fluid [1]. In accordance with this, they possess all the main advantages of conventional heat pipes, but, as distinct from the latter, have a considerably higher heat-transfer capacity, especially when operating in the ''antigravity'' regime, when heat is transferred from above downwards. Besides, LHPs possess a higher functional versatility, are adaptable to different operating conditions and provide great scope for various design embodiments. This is achieved at the expense of both the original design of the device and the properties of the wick - a special capillary structure used for the creation of capillary pressure. The LHP schematic diagram is given in Fig. 1. The device contains an evaporator and a condenser - heat exchanger connected by means of smooth-walled pipe-lines with a relatively small diameter intended for separate motion of vapor and liquid. At present loop heat pipes are most extensively employed in thermoregulation systems of spacecrafts. Miniature LHPs are used for cooling electronics and computers. At the same time there exists a considerable potential of using these devices for the recovery of low-grade (waste) heat from different sources, and also in systems of sun heat supply. In the latter case LHPs may serve as an efficient heat-transfer link between a sun collector and a heat accumulator, which has a low thermal resistance and does not consume any additional energy for pumping the working fluid between them. (orig.)

  4. Geothermal heat-pump systems of heat supply

    The data on the multilayer operation of the objects, located in the climatic conditions of the central area of Russia and equipped with the geothermal heat-pumping systems of the heat supply are presented. The results of the analytical studies on evaluating the geothermal heat-pumping systems of the heat supply integration efficiency into the structure of the energy supply system, prevailing in the country, are presented

  5. HEAT ACCUMULATION IN HELIUM GROUND SYSTEMS IN HEAT PUMP SUPPLY

    A. I. Kolosov

    2012-04-01

    Full Text Available Problem statement. The paper discusses the problem of estimation of prospects of heat accumulation in the combined systems of heat supply with the use of low potential energy of renewable sources (sun and ground and heat pumps for increase of their potential.Results and conclusions. The use of heat accumulators in combined heating systems that utilize low-potential solar and ground energy as primary energy sources and heat pumps to boost the po-tential of the latter was discussed. A method of calculating ground heat exchangers that use the heat pump cycle to increase a thermal potential of renewable energy sources was set forth. An at-tempt was made at addressing the problem of heat and mass transfer in ground when ground ac-cumulators like “a Field’s tube” are used: a geothermal circulation system comprises two wells (pumping and operational.

  6. HEAT ACCUMULATION IN HELIUM GROUND SYSTEMS IN HEAT PUMP SUPPLY

    A. I. Kolosov; A. A. Sedaev

    2012-01-01

    Problem statement. The paper discusses the problem of estimation of prospects of heat accumulation in the combined systems of heat supply with the use of low potential energy of renewable sources (sun and ground) and heat pumps for increase of their potential.Results and conclusions. The use of heat accumulators in combined heating systems that utilize low-potential solar and ground energy as primary energy sources and heat pumps to boost the po-tential of the latter was discussed. A method o...

  7. Model Scramjet Inlet Unstart Induced by Mass Addition and Heat Release

    Im, Seong-Kyun; Baccarella, Damiano; McGann, Brendan; Liu, Qili; Wermer, Lydiy; Do, Hyungrok

    2015-11-01

    The inlet unstart phenomena in a model scramjet are investigated at an arc-heated hypersonic wind tunnel. The unstart induced by nitrogen or ethylene jets at low or high enthalpy Mach 4.5 freestream flow conditions are compared. The jet injection pressurizes the downstream flow by mass addition and flow blockage. In case of the ethylene jet injection, heat release from combustion increases the backpressure further. Time-resolved schlieren imaging is performed at the jet and the lip of the model inlet to visualize the flow features during unstart. High frequency pressure measurements are used to provide information on pressure fluctuation at the scramjet wall. In both of the mass and heat release driven unstart cases, it is observed that there are similar flow transient and quasi-steady behaviors of unstart shockwave system during the unstart processes. Combustion driven unstart induces severe oscillatory flow motions of the jet and the unstart shock at the lip of the scramjet inlet after the completion of the unstart process, while the unstarted flow induced by solely mass addition remains relatively steady. The discrepancies between the processes of mass and heat release driven unstart are explained by flow choking mechanism.

  8. Additive Manufacturing for Cost Efficient Production of Compact Ceramic Heat Exchangers and Recuperators

    Shulman, Holly [Ceralink Incorporated, Troy, NY (United States); Ross, Nicole [Ceralink Incorporated, Troy, NY (United States)

    2015-10-30

    An additive manufacture technique known as laminated object manufacturing (LOM) was used to fabricate compact ceramic heat exchanger prototypes. LOM uses precision CO2 laser cutting of ceramic green tapes, which are then precision stacked to build a 3D object with fine internal features. Modeling was used to develop prototype designs and predict the thermal response, stress, and efficiency in the ceramic heat exchangers. Build testing and materials analyses were used to provide feedback for the design selection. During this development process, laminated object manufacturing protocols were established. This included laser optimization, strategies for fine feature integrity, lamination fluid control, green handling, and firing profile. Three full size prototypes were fabricated using two different designs. One prototype was selected for performance testing. During testing, cross talk leakage prevented the application of a high pressure differential, however, the prototype was successful at withstanding the high temperature operating conditions (1300 °F). In addition, analysis showed that the bulk of the part did not have cracks or leakage issues. This led to the development of a module method for next generation LOM heat exchangers. A scale-up cost analysis showed that given a purpose built LOM system, these ceramic heat exchangers would be affordable for the applications.

  9. Calcium bromide hydration for heat storage systems

    Ai Niwa; Noriyuki Kobayashi

    2015-01-01

    A chemical reaction is a common and simple way to produce heat for a heat storage system. The reaction produces heat energy without the use of electricity or fuel. The goal of this study was to develop a heat storage system for use in automobiles, which is able to provide heat rapidly via a hydration reaction. A heat storage system without an evaporator stores high-density heat and has a high heat output rate since the solid–liquid product that is formed is transferred as a heat medium to the...

  10. 添加回热回质器的太阳能恒温沼气系统性能%Performance of solar thermostatic marsh gas system with additional heat and mass recycling implement

    李金平; 翟盼盼; 周丹丹

    2013-01-01

    为了提高太阳能恒温沼气系统的太阳能利用率,给系统添加回热回质器,通过模拟新旧系统的换热过程,对新系统性能进行研究.根据兰州地区典型年最冷月气象资料计算的结果显示,新系统在30℃发酵条件下,回热回质器每天回热过程需要41 min,可把进料系统中的水由5℃提升至17.5℃;添加回热回质器后系统每日能耗从229~259 MJ降低到150~180 MJ,回收热量2 436.2 MJ,可节约太阳能集热器面积24.8 m2,新系统能耗降低到原系统总能耗的67.7%.研究结果也适用于其他热源加热的恒温沼气系统.%In order to improve the utilization rate of the solar energy in the solar thermostatic marsh gas system, a heat and mass recycling implement was added into this system. The performance of this system was investigated through the simulation of heat exchanging process in the original and new system. It was shown by the result of calculation of based on the meteorological data of the coldest month in typical year in Lanzhou area that the heat and mass recycling implement would need 41 min every day for the recycle during fermentation process at 30 ℃ and could increase the temperature of the water in the feed system from 5℃ to 17. 5 ℃. The energy consumption would be reduced from 220—260 MJ/d to 150—170 MJ/d and the heat recovery was 2 436. 2 MJ, saving the area of the solar collector by 24. 8 m2. Compared with that of original system, the total energy consumption of new system was reduced by 32. 3%. The investigation result would be as well suitable for other heat sources in the thermostatic marsh gas system.

  11. Performance enhancement of a household refrigerator by addition of latent heat storage

    Azzouz, K.; Leducq, D. [Cemagref: Refrigerating Processes Unit, Parc de Tourvoie BP 44, 92163 Antony (France); Gobin, D. [Univ Pierre et Marie Curie, CNRS, Lab FAST, F-91405 Orsay (France)

    2008-08-15

    This paper studies the effect of adding a phase change material (PCM) slab on the outside face of a refrigerator evaporator. A dynamic model of the vapour compression cycle including the presence of the phase change material and its experimental validation is presented. The simulation results of the system with PCM show that the addition of thermal inertia globally enhances heat transfer from the evaporator and allows a higher evaporating temperature, which increases the energy efficiency of the system. The energy stored in the PCM is yielded to the refrigerator cell during the off cycle and allows for several hours of continuous operation without power supply. (author)

  12. Heat exchanges in coarsening systems

    This paper is a contribution to the understanding of the thermal properties of ageing systems where statistically independent degrees of freedom with greatly separated time scales are expected to coexist. Focusing on the prototypical case of quenched ferromagnets, where fast and slow modes can be respectively associated with fluctuations in the bulk of the coarsening domains and in their interfaces, we perform a set of numerical experiments specifically designed to compute the heat exchanges between different degrees of freedom. Our studies promote a scenario with fast modes acting as an equilibrium reservoir to which interfaces may release heat through a mechanism that allows fast and slow degrees to maintain their statistical properties independently

  13. Rankine-cycle heating and cooling systems

    1979-01-01

    Design for domestic or commercial solar heating and cooling system based on rankine heat pump cycle includes detailed drawings, performance data, equipment specifications, and other pertinent information.

  14. Facets and cuts from additive systems

    Araoz, J.

    1994-12-31

    Integer Program Facets with non-negative entries could be derived from Additive System Problems, like Semigroup or Gomory`s Group Problems. These facets can be used as cuts for Branch and Cuts Algorithms. In fact, any Master Problem facet with some equal coefficients came from lifting a facet of a easily related Multivalued Additive System. A morphism type relation between problems allow us to obtain facets for Master Problems or cuts for Integer Programs. We use Knapsack Problems as examples either to present results about sequential lifting for non-Master Problems, pseudo-morphisms for facet generation for Master Problems and cut generation for Integer Programs solving small subadditive linear programs or to state open problems.

  15. Study of plutonium-addition systems

    Steady state phase diagrams and calculated values of concentrations on the solid and liquid curves, the steady state distribution coefficient and thermodynamic control are presented for temperatures ranging from the eutectic reaction temperatures to the Pu melting point temperature for binary systems plutonium-addition (Mg, Al, Si, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ga, Zr, Ru, Os, Th, U, Np). (J.P.)

  16. Design manual. [High temperature heat pump for heat recovery system

    Burch, T.E.; Chancellor, P.D.; Dyer, D.F.; Maples, G.

    1980-01-01

    The design and performance of a waste heat recovery system which utilizes a high temperature heat pump and which is intended for use in those industries incorporating indirect drying processes are described. It is estimated that use of this heat recovery system in the paper, pulp, and textile industries in the US could save 3.9 x 10/sup 14/ Btu/yr. Information is included on over all and component design for the heat pump system, comparison of prime movers for powering the compressor, control equipment, and system economics. (LCL)

  17. Calcium bromide hydration for heat storage systems

    Ai Niwa

    2015-12-01

    Full Text Available A chemical reaction is a common and simple way to produce heat for a heat storage system. The reaction produces heat energy without the use of electricity or fuel. The goal of this study was to develop a heat storage system for use in automobiles, which is able to provide heat rapidly via a hydration reaction. A heat storage system without an evaporator stores high-density heat and has a high heat output rate since the solid–liquid product that is formed is transferred as a heat medium to the object that requires heat. The exothermic heat produced from the solid–liquid reaction was measured, and the relationship between the equivalence ratio and the reaction heat was evaluated. The heat output and heat recovered by the heat storage system, which comprised a reaction vessel and a heat exchanger, were measured. We selected solid CaBr2 because it was the best metal halide for a hydration reaction and had a high heat yield from the dissolution reaction. With this system, we were able to achieve a heat recovery rate of 582 kJ/L-H2O. We found no degradation in the chemical composition of CaBr2 after it being recycled 100 times.

  18. Comprehensive Evaluation and Prediction of Enhancement of Boiling Heat Transfer with Additives

    2001-01-01

    A model of evaluation and prediction of enhancement of boiling heat transfer with additives has been propoeed according to fuzzy fundamentals. Correlative appraisement of boiling heat transfer augmentation was done with the model based on 39 additives which were tested by the authors and other researchers. The results show that the evaluation of 35 additives is consistent with experiments, which means that the accuracy of the model is 89.7 percent. In addition, the prediction of the ability of boiling heat transfer enhancement with sodium oleate,polyethylene glycol and Tween-40 is also in good agreement with correspondent experiments.

  19. Compact seasonal PCM heat storage for solar heating systems

    Dannemand, Mark

    Space heating of buildings and preparation of domestic hot water accounts for a large part of the society’s energy consumption. Solar radiation is an abundant and renewable energy source which can be harvested by solar collectors and used to cover heating demands in the built environment....... The seasonal availability of solar energy does however not match with the heating demands in buildings which typically are large in winter periods when limited solar energy is available. Heat can be stored over a few days in water stores but continuous heat losses limits the storage periods. The possibility...... of storing heat from summer where solar energy is widely available to winter periods where the heating demands are large, allows for implementing more renewable energy in our energy system. The phase change material (PCM) sodium acetate trihydrate (SAT) melts at 58 °C. The melting process requires...

  20. Heat pumps in combined heat and power systems

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    2014-01-01

    of the considered cases. When considering a case where the heat pump is located at a CHP (combined heat and power) plant, a configuration that increases the DH return temperature proposes the lowest operation cost, as low as 12 EUR MWh-1 for a 90 °C e 40 °C DH network. Considering the volumetric heating capacity......Heat pumps have previously been proposed as a way to integrate higher amounts of renewable energy in DH (district heating) networks by integrating, e.g., wind power. The paper identifies and compares five generic configurations of heat pumps in DH systems. The operational performance......, a third configuration is superior in all cases. Finally, the three most promising heat pump configurations are integrated in a modified PQ-diagram of the CHP plant. Each show individual advantages, and for two, also disadvantages in order to achieve flexible operation....

  1. Lighting system with heat distribution face plate

    Arik, Mehmet; Weaver, Stanton Earl; Stecher, Thomas Elliot; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Li, Ri

    2013-09-10

    Lighting systems having a light source and a thermal management system are provided. The thermal management system includes synthetic jet devices, a heat sink and a heat distribution face plate. The synthetic jet devices are arranged in parallel to one and other and are configured to actively cool the lighting system. The heat distribution face plate is configured to radially transfer heat from the light source into the ambient air.

  2. Decay Heat Removal System of Monju

    MONJU has three decay heat removal systems. The intermediate heat exchanger of the decay heat removal system is incorporated within the main IHX shell, and the heat from the secondary system is rejected to the air. Forced circulation is adopted for both primary and secondary coolant, though natural circulation capability is designed into the plant itself. Feasibility of rejecting the decay heat through steam plant is also being studied. In this paper, MONJU's decay heat removal system design, operational procedures, and the considerations behind the concept will be presented. (author)

  3. Eddy damping effect of additional conductors in superconducting levitation systems

    Jiang, Zhao-Fei; Gou, Xiao-Fan

    2015-12-01

    Passive superconducting levitation systems consisting of a high temperature superconductor (HTSC) and a permanent magnet (PM) have demonstrated several fascinating applications such as the maglev system, flywheel energy storage. Generally, for the HTSC-PM levitation system, the HTSC with higher critical current density Jc can obtain larger magnetic force to make the PM levitate over the HTSC (or suspended below the HTSC), however, the process of the vibration of the levitated PM, provides very limited inherent damping (essentially hysteresis). To improve the dynamic stability of the levitated PM, eddy damping of additional conductors can be considered as the most simple and effective approach. In this article, for the HTSC-PM levitation system with an additional copper damper attached to the HTSC, we numerically and comprehensively investigated the damping coefficient c, damping ratio, Joule heating of the copper damper, and the vibration frequency of the PM as well. Furthermore, we comparatively studied four different arrangements of the copper damper, on the comprehensive analyzed the damping effect, efficiency (defined by c/VCu, in which VCu is the volume of the damper) and Joule heating, and finally presented the most advisable arrangement.

  4. Ecological Optimization and Parametric Study of an Irreversible Regenerative Modified Brayton Cycle with Isothermal Heat Addition

    Vivek Tiwari; Subhash Chandra Kaushik; Sudhir Kumar Tyagi

    2003-01-01

    Abstract: An ecological optimization along with a detailed parametric study of an irreversible regenerative Brayton heat engine with isothermal heat addition have been carried out with external as well as internal irreversibilities. The ecological function is defined as the power output minus the power loss (irreversibility) which is ambient temperature times the entropy generation rate. The external irreversibility is due to finite temperature difference between the heat engine and the exter...

  5. Additive layer manufactured sinter-style aluminium/ammonia heat pipes

    Masoud Ameli, Seied

    2012-01-01

    A novel heat pipe (HP) manufacturing method has been developed based on an additive layer manufacturing technique called “selective laser melting” or SLM. This innovation is expected to benefit current applications of aluminium/ammonia heat pipes in space and terrestrial projects as well as many new HP applications. The project was jointly sponsored by the Northumbria University and Thermacore, a world leading heat pipe manufacturing company in the UK, and formed the feasibility stage of ...

  6. Optimization of Temperature Schedule Parameters on Heat Supply in Power-and-Heat Supply Systems

    V. A. Sednin; A. V. Sednin; M. L. Bogdanovich

    2014-01-01

    The paper considers problems concerning optimization of a temperature schedule in the district heating systems with steam-turbine thermal power stations having average initial steam parameters. It has been shown in the paper that upkeeping of an optimum network water temperature permits to increase an energy efficiency of heat supply due to additional systematic saving of fuel. 

  7. Optimization of Temperature Schedule Parameters on Heat Supply in Power-and-Heat Supply Systems

    V. A. Sednin

    2009-01-01

    Full Text Available The paper considers problems concerning optimization of a temperature schedule in the district heating systems with steam-turbine thermal power stations having average initial steam parameters. It has been shown in the paper that upkeeping of an optimum network water temperature permits to increase an energy efficiency of heat supply due to additional systematic saving of fuel. 

  8. OPTIMUM HEAT STORAGE DESIGN FOR SDHW SYSTEMS

    Shah, Louise Jivan; Furbo, Simon

    Two simulation models have been used to analyse the heat storage design’s influence on the thermal performance of solar domestic hot water (SDHW) systems. One model is especially designed for traditional SDHW systems based on a heat storage design where the solar heat exchanger is a built-in spiral...... of the tank design’s influence on the thermal performance of the systems is possible. By means of the calculations design rules for the two heat storage types are proposed....

  9. Effect of sulfur addition and heat treatment on electrical conductivity of barium vanadate glasses containing iron

    Highlights: → Selected glasses of V2O5-BaO-5Fe2O3 system have been transformed into nanomaterials by annealing at temperature close to crystallization temperature (Tc) for 1 h. → Glass ceramic nanocrystals are important because of their physical properties which are not obtainable in other classes of materials. → Crystal and grain sizes are the most significant structural parameters in electronic nanocrystalline glassy phases. → These phases have very high electrical conductivity, hence glass-ceramic nanocrystals are expected to be used, for example, as a gas sensor. - Abstract: Six glass samples with a composition of 75V2O5 + 10BaO + 15Fe2O3 mol%, with 0, 10, 15, 20, and 25 wt% of sulfur were prepared by using a quenching method. The samples were measured by XRD, DSC, TEM, Moessbauer spectrometry and D.C. conductivity. The prepared samples were heat treated at temperature close to their crystallization temperatures for 1 h, and then the previous measurements were repeated. The results showed that the treatment process caused the formation of V2O5 and FeVO4 nanocrystals with size of 17-25 nm dispersed in the glass matrix. The addition of sulfur reduced only the vanadium ions to V4+, while it was found that iron ions were Fe3+ only. D.C. conduction enhanced due to the small polaron or electron hopping from V4+ to V5+ ions. The heat treated samples exhibit much higher conductivity and much lower activation energy than the as-prepared glasses. The heat treated samples showed decreased thermal stability with the addition of sulfur. This considerable enhancement of electrical conductivity after nanocrystallization referred to the formation of extensive and dense network of electronic conduction paths which are situated between V2O5 nanocrystals and their surfaces.

  10. Influence of supplemental heat addition on performance of pilot-scale bioreactor landfills.

    Abdallah, Mohamed; Kennedy, Kevin; Narbaitz, Roberto; Warith, Mostafa; Sartaj, Majid

    2014-02-01

    Implementation of supplemental heat addition as a means of improving bioreactor landfill performance was investigated. The experimental work was conducted with two pilot-scale bioreactor setups (control cell and heated cell) operated for 280 days. Supplemental heat was introduced by recirculating leachate heated up to 35 °C compared to the control which used similar quantities of leachate at room temperature (21 ± 1 °C). The temporal and spatial effects of recirculating heated leachate on the landfill internal temperature were determined, and performance was assessed in terms of leachate parameters and biogas production. Recirculation of heated leachate helped establish balanced anaerobic microbial consortia that led to earlier (70 days) and greater (1.4-fold) organic matter degradation rates, as well as threefold higher methane production compared to the non-heated control. Despite the significant enhancements in performance resulting from supplemental heat addition, heated leachate recirculation did not significantly impact waste temperatures, and the effects were mainly restricted to short periods after recirculation and mostly at the upper layers of the waste. These findings suggest that improvements in bioreactor landfill performance may be achieved without increasing the temperature of the whole in-place waste, but rather more economically by raising the temperature at the leachate/waste interface which is also exposed to the maximum moisture levels within the waste matrix. PMID:23780222

  11. Carbon footprints of heating oil and LPG heating systems

    For European homes without access to the natural gas grid, the main fuels-of-choice for heating are heating oil and LPG. How do the carbon footprints of these compare? Existing literature does not clearly answer this, so the current study was undertaken to fill this gap. Footprints were estimated in seven countries that are representative of the EU and constitute two-thirds of the EU-27 population: Belgium, France, Germany, Ireland, Italy, Poland and the UK. Novelties of the assessment were: systems were defined using the EcoBoiler model; well-to-tank data were updated according to most-recent research; and combustion emission factors were used that were derived from a survey conducted for this study. The key finding is that new residential heating systems fuelled by LPG are 20% lower carbon and 15% lower overall-environmental-impact than those fuelled by heating oil. An unexpected finding was that an LPG system's environmental impact is about the same as that of a bio heating oil system fuelled by 100% rapeseed methyl ester, Europe's predominant biofuel. Moreover, a 20/80 blend (by energy content) with conventional heating oil, a bio-heating-oil system generates a footprint about 15% higher than an LPG system's. The final finding is that fuel switching can pay off in carbon terms. If a new LPG heating system replaces an ageing oil-fired one for the final five years of its service life, the carbon footprint of the system's final five years is reduced by more than 50%.

  12. Heat pump for district cooling and heating at Oslo Airport, Gardermoen[Aquifer thermal energy systems (ATES)

    Eggen, Geir; Vangsnes, Geir

    2006-07-01

    At Gardermoen, one of the largest groundwater reservoirs in Norway is located. This aquifer is used for both heating and cooling of Gardermoen Airport. In the summer, ground water is pumped from cold wells and used for cooling before it is returned to the warm wells. In winter, this process is turned around, as ground water from the warm wells is used as heat source for the heat pump. The heat pump is mainly designed for cooling, and the design cooling demand is 9 MW. The district cooling water is pre-cooled by the ground water, and post cooled by the combined heat pump/refrigeration plant. The base heat load is covered by the heat pump. Additional heat is supplied from a heat energy central with bio fuels as well as oil heated and electrically heated boilers. During the last years, heat production from the heat pump was about 11 GWh/year, and the heat pump also provides about 8 GWh/year of the cooling demand. In addition, approximately 3 GWh/year cold is produced by direct heat exchange with ground water. Compared with a district heating system heated by fossil fuels, and a conventional refrigeration system for district cooling, the pay back period for the aquifer heat pump system is within a couple of years (author) (ml)

  13. Implementing slab solar water heating system

    Raveendran, S. K.; Shen, C. Q.

    2015-08-01

    Water heating contributes a significant part of energy consumption in typical household. One of the most employed technologies today that helps in reducing the energy consumption of water heating would be conventional solar water heating system. However, this system is expensive and less affordable by most family. The main objective of this project is to design and implement an alternative type of solar water heating system that utilize only passive solar energy which is known as slab solar water heating system. Slab solar water heating system is a system that heat up cold water using the solar radiance from the sun. The unique part of this system is that it does not require any form of electricity in order to operate. Solar radiance is converted into heat energy through convection method and cold water will be heated up by using conduction method [1]. The design of this system is governed by the criteria of low implementation cost and energy saving. Selection of material in the construction of a slab solar water heating system is important as it will directly affect the efficiency and performance of the system. A prototype has been built to realize the idea and it had been proven that this system was able to provide sufficient hot water supply for typical household usage at any given time.

  14. A district heating system as a sink for carbon dioxide

    Within a strategy of carbn dioxide (CO2) abatement, district heating systems, driven by small nuclear heating reactors, could be used not only to deliver sensible heat to the consumers, but also as a CO2-absorber/desorber system for the collection of diffusively scattered CO2-sources. For this, potassium carbonate (K2CO3) is dissolved in the heating system which converts into potassium bicarbonate (KHCO3) when CO2 from flue gases is absorbed. At the heating reactor CO2 is desorbed and disposed of. Hence, a district heating system could work as a 'CO2-collecting system', too. Using this additional feature of a district heating system, its so-called effective, climate-related, CO2-neutrality factor is increased by almost a factor of three compared with the direct substitution effect of the CO2-free nuclear heating energy alone. Such a hybrid system could be of interest in a transitional phase when nuclear district heating energy will penetrate into a yet fossil-fuelled heating market. (orig.)

  15. Heat Roadmap Europe: Combining district heating with heat savings to decarbonise the EU energy system

    Six different strategies have recently been proposed for the European Union (EU) energy system in the European Commission's report, Energy Roadmap 2050. The objective for these strategies is to identify how the EU can reach its target of an 80% reduction in annual greenhouse gas emissions in 2050 compared to 1990 levels. None of these scenarios involve the large-scale implementation of district heating, but instead they focus on the electrification of the heating sector (primarily using heat pumps) and/or the large-scale implementation of electricity and heat savings. In this paper, the potential for district heating in the EU between now and 2050 is identified, based on extensive and detailed mapping of the EU heat demand and various supply options. Subsequently, a new ‘district heating plus heat savings’ scenario is technically and economically assessed from an energy systems perspective. The results indicate that with district heating, the EU energy system will be able to achieve the same reductions in primary energy supply and carbon dioxide emissions as the existing alternatives proposed. However, with district heating these goals can be achieved at a lower cost, with heating and cooling costs reduced by approximately 15%. - Highlights: • A new heat atlas is created for the EU27. • District heating and renewable heat potentials are determined for 2030 and 2050. • A new heat strategy based on district heating and individual heat pumps is designed for the EU27. • This new heat strategy is compared to the energy efficiency scenario proposed by the European Commission. • Results indicate that this new heat strategy can reduce heating and cooling costs by ∼15%, which is €100 billion per year

  16. Potential and limits of sodium hydroxide as an additive to the binary system ammonia/water in absorption heat pumps; Potenzial und Grenzen von Natriumhydroxid als Zusatz zum Stoffpaar Ammoniak/Wasser in Absorptions-Waermepumpen

    Kotenko, Oleksandr; Moser, Harald; Fenzl, Thomas; Rieberer, Rene [Technische Univ. Graz (Austria). Inst. fuer Waermetechnik

    2011-07-01

    Several authors proposed the use of sodium hydroxide (NaOH) as an additive to the ammonia/water working fluid mixture (NH{sub 3} / H{sub 2}O), especially in solar air conditioners. Measured vapour-liquid equilibrium data of this tertiary mixture are found in the relevant literature. Thermodynamic calculations carried out with these data show that the efficiency (COP) will be enhanced in theory while the rectification time will decrease. To verify these theoretical considerations and to gain practical experience with the tertiary mixture NH{sub 3} / H{sub 2}O / NaOH, a test stand was constructed at the Institut fuer Waermetechnik, and measurements were carried out on the mixture NH{sub 3} / H{sub 2}O, i.e. without NaOH, and with 5% NaOH. The technical feasibility of the process was established, although NaOH depositions in the refrigerating circuit caused operational disturbances, so that the mixture had to be renewed regularly and the plant had to be flushed with water. The expected efficiency improvement was not observed. Analyses using ''ASPEN Plus'' showed that this was the result of lower absorber efficiency, which may be due to the higher circulation rate and higher viscosity of the working fluid mixture. Measurements showed a moderate improvements of heat transfer in the expeller after addition of NaOH; no effects were found in the evaporator, solvent heat exchanger and rectification column. The findings suggest that fast implementation of NH{sub 3} / H{sub 2}O / NaOH-AWP is not realistic. Considerable research and development will still be required for optimisation of the absorber for operation with NaOH. [German] Die Verwendung von Natriumhydroxid (NaOH) als Zusatz zum Arbeitsstoffgemisch Ammoniak / Wasser (NH{sub 3} / H{sub 2}O) wurde von verschiedenen Autoren insbesondere fuer das Anwendungsgebiet der solaren Klimatisierung vorgeschlagen. In der einschlaegigen Literatur wurden gemessene Dampf-Fluessig-Gleichgewichts-Daten von diesem

  17. Solar dynamic space power system heat rejection

    Carlson, A. W.; Gustafson, E.; Mclallin, K. L.

    1986-01-01

    A radiator system concept is described that meets the heat rejection requirements of the NASA Space Station solar dynamic power modules. The heat pipe radiator is a high-reliability, high-performance approach that is capable of erection in space and is maintainable on orbit. Results are present of trade studies that compare the radiator system area and weight estimates for candidate advanced high performance heat pipes. The results indicate the advantages of the dual-slot heat pipe radiator for high temperature applications as well as its weight-reduction potential over the range of temperatures to be encountered in the solar dynamic heat rejection systems.

  18. WASTE HEAT RECOVERY IN HEAT PUMP SYSTEMS: SOLUTION TO REDUCE GLOBAL WARMING

    Y. Baradey; M. N. A. Hawlader; Ahmad Faris Ismail; Meftah Hrairi

    2015-01-01

    Energy conversion technologies, where waste heat recovery systems are included, have received significant attention in recent years due to reasons that include depletion of fossil fuel, increasing oil prices, changes in climatic conditions, and global warming. For low temperature applications, there are many sources of thermal waste heat, and several recovery systems and potential useful applications have been proposed by researchers [1-4]. In addition, many types of equipment are used to rec...

  19. Waste Heat Recapture from Supermarket Refrigeration Systems

    Fricke, Brian A [ORNL

    2011-11-01

    The objective of this project was to determine the potential energy savings associated with improved utilization of waste heat from supermarket refrigeration systems. Existing and advanced strategies for waste heat recovery in supermarkets were analyzed, including options from advanced sources such as combined heat and power (CHP), micro-turbines and fuel cells.

  20. Novel heat recovery systems for building applications

    Ahmad, Mardiana Idayu

    2011-01-01

    The work presented in this thesis will explore the development of novel heat recovery systems coupled with low carbon technologies, and its integration to become one device with multifunction (building integrated heat recovery/cooling/air dehumidifier. In the first part of this thesis, an experimental performance of an individual heat recovery unit using Micro Heat and Mass Cycle Core (MHM3C) made of fibre papers with cross flow arrangement has been carried out. The unit was tested in an env...

  1. Dynamics of heat transfer between nano systems

    Biehs, Svend-Age; Agarwal, Girish S.

    2012-01-01

    We develop a dynamical theory of heat transfer between two nano systems. In particular, we consider the resonant heat transfer between two nanoparticles due to the coupling of localized surface modes having a finite spectral width. We model the coupled nanosystem by two coupled quantum mechanical oscillators, each interacting with its own heat bath, and obtain a master equation for the dynamics of heat transfer. The damping rates in the master equation are related to the lifetimes of localize...

  2. Control challenges in domestic heating systems

    Thybo, Honglian; Larsen, Lars F. S.; Weitzmann, Peter

    2007-01-01

    The objective of this paper is to analyze domestic heating applications and identify unfavorable building constructions and control challenges to be addressed by high performance heating control systems. Heating of domestic houses use a large amount of the total energy consumption in Scandinavia...... with water based floor heating affect the control challenge. The analysis is documented with simulation results........ Hence the potential of reducing energy consumption by applying high performance control is vast. Indoor climate issues are becoming more in focus, which also leads to a demand for high performance heating systems. The paper presents an analysis of how the building elements of today's domestic houses...

  3. Residential CO{sub 2} heat pump system for combined space heating and hot water heating

    Stene, Joern

    2004-02-01

    Carbon dioxide (CO{sub 2}, R-744) has been identified as a promising alternative to conventional working fluids in a number of applications due to its favourable environmental and thermophysical properties. Previous work on residential CO{sub 2} heat pumps has been dealing with systems for either space heating or hot water heating, and it was therefore considered interesting to carry out a theoretical and experimental study of residential CO{sub 2} heat pump systems for combined space heating and hot water heating - o-called integrated CO{sub 2} heat pump systems. The scope of this thesis is limited to brine-to-water and water-to-water heat pumps connected to low-temperature hydronic space heating systems. The main conclusions are: (1) Under certain conditions residential CO{sub 2} heat pump systems for combined space heating and hot water heating may achieve the same or higher seasonal performance factor (SPF) than the most energy efficient state-of-the-art brine-to-water heat pumps. (2) In contrary to conventional heat pump systems for combined space heating and DHW heating, the integrated CO{sub 2} heat pump system achieves the highest COP in the combined heating mode and the DHW heating mode, and the lowest COP in the space heating mode. Hence, the larger the annual DHW heating demand, the higher the SPF of the integrated CO{sub 2} heat pump system. (3) The lower the return temperature in the space heating system and the lower the DHW storage temperature, the higher the COP of the integrated CO{sub 2} heat pump. A low return temperature in the space heating system also results in a moderate DHW heating capacity ratio, which means that a relatively large part of the annual space heating demand can be covered by operation in the combined heating mode, where the COP is considerably higher than in the space heating mode. (4) During operation in the combined heating mode and the DHW heating mode, the COP of the integrated CO{sub 2} heat pump is heavily influenced by

  4. Intensification of Convective Heat Transfer in Heating Device of Mobile Heating System with BH-Heat Generator

    N. Nesenchuk

    2013-01-01

    Full Text Available Directions pertaining to intensification of convective heat transfer in a soft heating device have been experimentally investigated  in the paper and the most efficient one has been selected that is creation of artificial roughness on the device surface. The considered heating device for a heat supply system of a mobile object has been made of soft polymer material (polyvinyl chloride. Following  evaluation results of  heat exchange intensification a criteria equation has been obtained for calculation of external heat transfer with due account of heat transfer intensification.

  5. Advances in Solar Heating and Cooling Systems

    Ward, Dan S.

    1976-01-01

    Reports on technological advancements in the fields of solar collectors, thermal storage systems, and solar heating and cooling systems. Diagrams aid in the understanding of the thermodynamics of the systems. (CP)

  6. Improving Process Heating System Performance v3

    None

    2016-04-11

    Improving Process Heating System Performance: A Sourcebook for Industry is a development of the U.S. Department of Energy (DOE) Advanced Manufacturing Office (AMO) and the Industrial Heating Equipment Association (IHEA). The AMO and IHEA undertook this project as part of an series of sourcebook publications developed by AMO on energy-consuming industrial systems, and opportunities to improve performance. Other topics in this series include compressed air systems, pumping systems, fan systems, steam systems, and motors and drives

  7. Design of an additional heat sink based on natural circulation in pressurized water reactors

    Residual heat removal through the steam generators in Nuclear Power Plant with pressurized water reactors (PWR) or pressurized heavy water reactors (PHWR in pressured vessel or pressured tube types) requires the maintenance of the steam generator inventory and the availability of and appropriate heat sink, which are based on the operability of the steam generators feedwater system. This paper describes the conceptual design of an assured heat removal system which includes only passive elements and is based on natural circulation. The system can supplement the original systems of the plant. The new system includes a condenser/boiler heat exchanger to condense the steam produced in the steam generator, transferring the heat to the water of an open pool at atmospheric pressure. The condensed steam flows back to the steam generators by natural circulation effects. The performance of an Atucha type PHWR nuclear power station with and without the proposed system is calculated in an emergency power case for the first 5000 seconds after the incident. The analysis shows that the proposed system offers the possibility to cool-down the plant to a low energy state during several hours and avoids the repeated actuation of the primary and secondary system safety valves. (Author)

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

    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 H...

  9. Radiant Heating and Cooling Systems. Part one

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    The use of radiant heating systems has several thousand years of history.1,2 The early stage of radiant system application was for heating purposes, where hot air from flue gas (cooking, fires) was circulated under floors or in walls. After the introduction of plastic piping water-based radiant h...

  10. Radiant Heating and Cooling Systems. Part two

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    Control of the heating and cooling system needs to be able to maintain the indoor temperatures within the comfort range under the varying internal loads and external climates. To maintain a stable thermal environment, the control system needs to maintain the balance between the heat gain/loss of...

  11. Rankine cycle waste heat recovery system

    Ernst, Timothy C.; Nelson, Christopher R.

    2015-09-22

    A waste heat recovery (WHR) system connects a working fluid to fluid passages formed in an engine block and/or a cylinder head of an internal combustion engine, forming an engine heat exchanger. The fluid passages are formed near high temperature areas of the engine, subjecting the working fluid to sufficient heat energy to vaporize the working fluid while the working fluid advantageously cools the engine block and/or cylinder head, improving fuel efficiency. The location of the engine heat exchanger downstream from an EGR boiler and upstream from an exhaust heat exchanger provides an optimal position of the engine heat exchanger with respect to the thermodynamic cycle of the WHR system, giving priority to cooling of EGR gas. The configuration of valves in the WHR system provides the ability to select a plurality of parallel flow paths for optimal operation.

  12. Comprehensive thermodynamic analysis of a renewable energy sourced hybrid heating system combined with latent heat storage

    Highlights: • An experimental thermal investigation of hybrid renewable heating system is presented. • Analyses were done by using real data obtained from a prototype structure. • Exergy efficiency of system components investigated during discharging period are close to each other as 32%. • The average input energy and exergy rates to the LHS were 0.770 and 0.027 kW. • Overall total energy and exergy efficiencies of LHS calculated as 72% and 28.4%. - Abstract: In this study an experimental thermal investigation of hybrid renewable heating system is presented. Latent heat storage stores energy, gained by solar collectors and supplies medium temperature heat to heat pump both day time also night time while solar energy is unavailable. In addition to this an accumulation tank exists in the system as sensible heat storage. It provides supply–demand balance with storing excess high temperature heat. Analyses were done according to thermodynamic’s first and second laws by using real data obtained from a prototype structure, built as part of a project. Results show that high percent of heat loses took place in heat pump with 1.83 kW where accumulator-wall heating cycle followed it with 0.42 kW. Contrarily highest break-down of exergy loses occur accumulator-wall heating cycle with 0.28 kW. Averagely 2.42 kW exergy destruction took place in whole system during the experiment. Solar collectors and heat pump are the promising components in terms of exergy destruction with 1.15 kW and 1.09 kW respectively. Exergy efficiency of system components, investigated during discharging period are in a close approximately of 32%. However, efficiency of solar collectors and charging of latent heat storage are 2.3% and 7% which are relatively low. Average overall total energy and exergy efficiencies of latent heat storage calculated as 72% and 28.4% respectively. Discharging energy efficiency of latent heat storage is the highest through all system components. Also heat

  13. The effects of the coke addition and the heating time on the efficiency of chlorination process

    The preparation of mixed pellet, ZrO2, coke and sucrose, for chlorinating process of ZrO2 pellet has been performed. In this experiments the studied parameters were coke addition and the heating time. The addition of coke was 9.72 grams, 10.5 grams and 11 for the mixture of the 87 grams ZrO2 and 3.5 grams sucrose. The purpose of the coke addition is to from ZrC, which is corresponding to Kroll process with carbon-chlor methos. The weight of cokes had been calculated beyond the stoichiometry. The heating times was held in 10 minutes, 15 minutes, and 20 minutes at the temperature of 100oC that was below the evaporation coke temperature of 315oC. The result show that the efficiency of chlorinating of ZrO2 pellet could be reached of 82.16% with the addition of coke mass of 11 grams at the heating temperature of 100oC with the heating time of 20 minutes

  14. Transport code for Tokamak including some anomalous electronic effects and lower hybrid additional heating terms

    The operation of a tokamak device, the MHD equations, the transport phenomena and the inelastic processes are reviewed. The additional heating by waves at the lower hybrid frequency is studied. The numerical analysis methods employed are described and the results obtained discussed

  15. 3D Additive Construction with Regolith for Surface Systems

    Mueller, Robert P.

    2014-01-01

    Planetary surface exploration on Asteroids, the Moon, Mars and Martian Moons will require the stabilization of loose, fine, dusty regolith to avoid the effects of vertical lander rocket plume impingement, to keep abrasive and harmful dust from getting lofted and for dust free operations. In addition, the same regolith stabilization process can be used for 3 Dimensional ( 3D) printing, additive construction techniques by repeating the 2D stabilization in many vertical layers. This will allow in-situ construction with regolith so that materials will not have to be transported from Earth. Recent work in the NASA Kennedy Space Center (KSC) Surface Systems Office (NE-S) Swamp Works and at the University of Southern California (USC) under two NASA Innovative Advanced Concept (NIAC) awards have shown promising results with regolith (crushed basalt rock) materials for in-situ heat shields, bricks, landing/launch pads, berms, roads, and other structures that could be fabricated using regolith that is sintered or mixed with a polymer binder. The technical goals and objectives of this project are to prove the feasibility of 3D printing additive construction using planetary regolith simulants and to show that they have structural integrity and practical applications in space exploration.

  16. Modular district heating system MODiS

    Sipilae, K.; Ranne, A.; Koljonen, T. [VTT Energy, Espoo (Finland). Energy Systems

    2000-12-01

    MODiS (Modular District Heating System) products were developed for either building an entirely new district heating (DH) system or for renovating and extending an existing system. MODiS products comprise highly integrated prefabricated and pre- tested modules, where the modules themselves may be boilers, pumping stations, substations, metering devices, automation equipment, planning tools, information and management systems. The MODiS Concept tool was developed by VTT Energy for the rough planning of a MODiS district heating system. As a result, the MODiS Concept model can give the budget for a DH-system divided into the boiler plant, the district heating pipelines and the consumer substations. The annual investment and running cost of the system are evaluated. A dynamic simulation model for MODiS was also created with a real time simulation tool called APROS. The simulator can be used for studying normal operation, behaviour under emergency conditions, and process failures. The APROS simulation program has also been used to investigate an ejector connection in an apartment building and for analysing the operation of the ejector in relation to the entire heating system. A DH system in a Russian district heating zone was modelled with the programs. A knowledge-based tool, PIPECOR, has been developed and it estimates the remaining service life of the pipelines under the defined conditions, and the current corrosion rate. Renovation principles for the East European district heating systems have been developed during the project. (orig.)

  17. Energy cascading in large district heating systems

    The study shows that it is possible to force a district heating system with low flow- and return-line temperatures by using energy cascading, which means that the heat is transmitted to several consumer regions at different temperature ranges. Thereby results an evident reduction of the electric power loss in the power station and the district heating system can be supplied now economically with heat by a nuclear power station built at a great distance to the supply region because of reasons of security. (M.S.)

  18. Specifying the auxiliary heating system on TFCX

    This paper reviews the status of heating systems for the TFCX-S (all superconducting coil) and TFCX-H (hybrid coil) options. Three systems were defined; preheating (electron), current drive, and bulk (ion) heating. Application of systems engineering techniques facilitated fruitful discussions of requirements and their impact on equipment between physicists and engineers. A low-cost, flexible combination of systems allows plasma experiments using all rf startup and current drive

  19. Demonstrations of electric heating systems. Final Report

    Haapakoski, M.; Laitila, R.; Ruska, T.

    1998-07-01

    In 1991, Imatran Voima launched the Demonstration Project of Electric Heating Systems. The project investigated in detail the energy consumption, housing comfort and electric power output rates of approximately one hundred electrically heated single-family houses and updated the investment cost information of heating systems. The project implemented and monitored quality electric heating concepts that guarantee a high standard of housing comfort. The targets in the project provided with combinations of floor, ceiling and window heating systems totalled 33. Furthermore, the project included 42 targets provided with water-circulated floor or radiator heating systems and 22 houses that had moved from oil or district heating systems into electric heating. The number of metering years received in the energy consumption measurements totalled 339. During the course of the project, six partial reports, one master's thesis and three summary reports were published. This is the final report of the project. It deals in brief with the major results. The best electric heating concept, in terms of housing comfort, is a floor heating system using cables supplemented by ceiling and window heating. Thanks to the heating units installed in the structures, the operative temperature grows by about one degree in comparison with a corresponding target heated with radiators. A typical, room-specifically-heated 140 m{sup 2} house consumes a total of 24,000 kWh of energy per year. Of this amount, electric space heating accounts for 11,500 kWh, heating with wood for 1,500 kWh, heating of tap water for 4,000 kWh and household electricity for 7,000 kWh. In a house provided with a water-circulated electric heating system the total energy consumption is, owing to the adjustment and storage losses, about 10 % higher. Of the energy consumption in the house, most part takes place during the period of nighttime electricity. The nighttime load in a 24-hour period with very low temperatures

  20. Solar/electric heating systems for the future energy system

    Furbo, S.; Dannemand, M.; Perers, B. [and others

    2013-05-15

    The aim of the project is to elucidate how individual heating units for single family houses are best designed in order to fit into the future energy system. The units are based on solar energy, electrical heating elements/heat pump, advanced heat storage tanks and advanced control systems. Heat is produced by solar collectors in sunny periods and by electrical heating elements/heat pump. The electrical heating elements/heat pump will be in operation in periods where the heat demand cannot be covered by solar energy. The aim is to use the auxiliary heating units when the electricity price is low, e.g. due to large electricity production by wind turbines. The unit is equipped with an advanced control system where the control of the auxiliary heating is based on forecasts of the electricity price, the heat demand and the solar energy production. Consequently, the control is based on weather forecasts. Three differently designed heating units are tested in a laboratory test facility. The systems are compared on the basis of: 1) energy consumption for the auxiliary heating; 2) energy cost for the auxiliary heating; 3) net utilized solar energy. Starting from a normal house a solar combi system (for hot water and house heating) can save 20-30% energy cost, alone, depending on sizing of collector area and storage volume. By replacing the heat storage with a smart tank based on electric heating elements and a smart control based on weather/load forecast and electricity price information 24 hours ahead, another 30-40% can be saved. That is: A solar heating system with a solar collector area of about 10 m{sup 2}, a smart tank based on electric heating element and a smart control system, can reduce the energy costs of the house by at least 50%. No increase of heat storage volume is needed to utilize the smart control. The savings in % are similar for different levels of building insulation. As expected a heat pump in the system can further reduce the auxiliary electricity

  1. Air leakage in residential solar heating systems

    Shingleton, J. G.; Cassel, D. E.; Overton, R. L.

    1981-02-01

    A series of computer simulations was performed to evaluate the effects of component air leakage on system thermal performance for a typical residential solar heating system, located in Madison, Wisconsin. Auxiliary energy required to supplement solar energy for space heating was determined using the TRNSYS computer program, for a range of air leakage rates at the solar collector and pebble bed storage unit. The effects of heat transfer and mass transfer between the solar equipment room and the heated building were investigated. The effect of reduced air infiltration into the building due to pressurized by the solar air heating system were determined. A simple method of estimating the effect of collector array air leakage on system thermal performance was evaluated, using the f CHART method.

  2. Review of preliminary additional heating experiments in JT-60 (Aug. - Nov., 1986)

    This is a prompt report on preliminary additional heating experiments in JT-60 from August to November in 1986. Neutral beam heating power was raised up to 20 MW in about a month. Plasma stored energy is about 2 MJ and energy confinement time is 0.1 ∼ 0.12 sec with the maximum heating power. The energy confinement time shows L-mode like deterioration with power, while it has little dependence on electron density. The maximum ion temperature of ∼ 7 keV and electron temperature of 4.5 keV were obtained at relatively low electron density (n-bare = 2 - 3 x 1019 m-3). Lower hybrid wave could efficiently drive plasma current up to 1.7 MA with 1.2 MW LH power. The current drive efficiency is 1 ∼ 1.7 in ohmically heated plasmas and 2 ∼ 2.8 in NB heated plasmas. Futhermore the energy confinement was improved when neutral beam was injected into entirely current driven discharges of 1 MA by LH in contrast to inductively driven target plasmas. Similar improvement in energy confinement was observed during combined heating with NB and ion cyclotron wave. (author)

  3. Ion Cyclotron Resonance Heating System on EAST

    Wang, Lei

    2009-08-01

    Ion cyclotron resonance heating (ICRH) system which will provide at least than 10 MW heating power, with a frequency range from 25 MHz to 100 MHz, is being built up for the EAST. The system includes high-power and wide-frequency radio amplifier, transmission line as well as resonant double loop (RDL) antenna. As a part of this system a sub-ICRH system unit with a ultimate output power of 2.5 MW was set up and employed for heating experiment. The maximum of the launched power reached 200 kW in 2008.

  4. Ion Cyclotron Resonance Heating System on EAST

    Ion cyclotron resonance heating (ICRH) system which will provide at least than 10 MW heating power, with a frequency range from 25 MHz to 100 MHz, is being built up for the EAST. The system includes high-power and wide-frequency radio amplifier, transmission line as well as resonant double loop (RDL) antenna. As a part of this system a sub-ICRH system unit with a ultimate output power of 2.5 MW was set up and employed for heating experiment. The maximum of the launched power reached 200 kW in 2008. (magnetically confined plasma)

  5. Safety characteristics of decay heat removal systems

    Safety features of the decay heat removal systems including power sunply and final heat sink are described. A rather high reliability and an utmost degree of independence from energy supply are goals to be attained in the design of the European Fast Reactor (EFR) decay heat removal scheme. Natural circulation is an ambitious design goal for EFR. All the considerations are performed within the frame of risk minimization

  6. Estimation of low-potential heat recuperation efficiency of smoke fumes in a condensation heat utilizer under various operation conditions of a boiler and a heating system

    Ionkin, I. L.; Ragutkin, A. V.; Luning, B.; Zaichenko, M. N.

    2016-06-01

    For enhancement of the natural gas utilization efficiency in boilers, condensation heat utilizers of low-potential heat, which are constructed based on a contact heat exchanger, can be applied. A schematic of the contact heat exchanger with a humidifier for preheating and humidifying of air supplied in the boiler for combustion is given. Additional low-potential heat in this scheme is utilized for heating of the return delivery water supplied from a heating system. Preheating and humidifying of air supplied for combustion make it possible to use the condensation utilizer for heating of a heat-transfer agent to temperature exceeding the dewpoint temperature of water vapors contained in combustion products. The decision to mount the condensation heat utilizer on the boiler was taken based on the preliminary estimation of the additionally obtained heat. The operation efficiency of the condensation heat utilizer is determined by its structure and operation conditions of the boiler and the heating system. The software was developed for the thermal design of the condensation heat utilizer equipped by the humidifier. Computation investigations of its operation are carried out as a function of various operation parameters of the boiler and the heating system (temperature of the return delivery water and smoke fumes, air excess, air temperature at the inlet and outlet of the condensation heat utilizer, heating and humidifying of air in the humidifier, and portion of the circulating water). The heat recuperation efficiency is estimated for various operation conditions of the boiler and the condensation heat utilizer. Recommendations on the most effective application of the condensation heat utilizer are developed.

  7. Influence of Alumina Addition to Aluminum Fins for Compact Heat Exchangers Produced by Cold Spray Additive Manufacturing

    Farjam, Aslan; Cormier, Yannick; Dupuis, Philippe; Jodoin, Bertrand; Corbeil, Antoine

    2015-10-01

    In this work, aluminum and aluminum-alumina powder mixtures were used to produce pyramidal fin arrays on aluminum substrates using cold spray as an additive manufacturing process. Using aluminum-alumina mixtures instead of pure aluminum powder could be seen as a cost-effective measure, preventing nozzle clogging or the need to use expensive polymer nozzles that wear out rapidly during cold spray. The fin geometries that were produced were observed using a 3D digital microscope to determine the flow passages width and fins' geometric details. Heat transfer and pressure drop tests were carried out using different ranges of appropriate Reynolds numbers for the sought commercial application to compare each fin array and determine the effect of alumina content. It was found that the presence of alumina reduces the fins' performance when compared to pure aluminum fins but that they were still outperforming traditional fins. Numerical simulations were performed to model the fin arrays and were used to predict the pressure loss in the fin array and compare these results with experimental values. The numerical model opens up new avenues in predicting different applicable operating conditions and other possible fin shapes using the same fin composition, instead of performing costly and time-consuming experiments.

  8. Exergy performance of different space heating systems: A theoretical study

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    Three space heating systems (floor heating with different floor covering resistances, radiator heating with different working temperatures, warm-air heating with and without heat recovery) were compared using a natural gas fired condensing boiler as the heat source. For the floor heating systems,...

  9. COMPARATIVE EFFICIENCY OF HEAT-PUMPS APPLICATION IN LOW TEMPERATURE HEAT SUPPLY SYSTEMS

    M. N. Chepurnoy

    2015-10-01

    Full Text Available The  article  considers  comparative  operation-efficiency  of  the  low-temperature  heatsupply systems with heat pumping plants (HPP and with hot-water boilers. The paper shows that for energy evaluation of the alternative heat-supply systems effectiveness one cannot employ the transformation ratio (heating coefficient and the fuel heat-utilization factor in the HPP. Nonetheless the transformation ratio enters the formulae designating the efficiency of HPP operation. The authors obtain a generalized formula for ascertainment of transformation ratio and suggest evaluating the operation efficiency of the heat-supply systems by means of indicators specifying relative gain in the exergy-efficiency factor, fuel savings and saving expenditures connected with fuel and utilities. They attain formulae and build nomographic charts for those indicators ascertainment. The operation-efficiency comparative analysis of the low-temperature heat supply systems with HPP and with hot-water boilers shows that the HPP systems increase their effectiveness with transformation ratio, fuel price increase as well as with low electric-energy prices. The article specifies that with fuel low prices, the transformation-ratios limiting values with which the HPP operation-efficacy gains, grow. Energy-efficiency increase in the HPP does not always guaranty their economic effectiveness. These findings are true only for the heating systems. The hot water-supply systems will require the HPP condenser water additional heating to the assumed temperature from another thermal source, which reduces the effectiveness of the heat pump plants utilizing.

  10. District Heating Systems Performance Analyses. Heat Energy Tariff

    Ziemele, Jelena; Vigants, Girts; Vitolins, Valdis; Blumberga, Dagnija; Veidenbergs, Ivars

    2014-12-01

    The paper addresses an important element of the European energy sector: the evaluation of district heating (DH) system operations from the standpoint of increasing energy efficiency and increasing the use of renewable energy resources. This has been done by developing a new methodology for the evaluation of the heat tariff. The paper presents an algorithm of this methodology, which includes not only a data base and calculation equation systems, but also an integrated multi-criteria analysis module using MADM/MCDM (Multi-Attribute Decision Making / Multi-Criteria Decision Making) based on TOPSIS (Technique for Order Performance by Similarity to Ideal Solution). The results of the multi-criteria analysis are used to set the tariff benchmarks. The evaluation methodology has been tested for Latvian heat tariffs, and the obtained results show that only half of heating companies reach a benchmark value equal to 0.5 for the efficiency closeness to the ideal solution indicator. This means that the proposed evaluation methodology would not only allow companies to determine how they perform with regard to the proposed benchmark, but also to identify their need to restructure so that they may reach the level of a low-carbon business.

  11. MULTIFUNCTIONAL SOLAR SYSTEMS FOR HEATING AND COOLING

    Doroshenko A.V.

    2010-12-01

    Full Text Available The basic circuits of multifunctional solar systems of air drainage, heating (hot water supply and heating, cooling and air conditioning are developed on the basis of open absorption cycle with a direct absorbent regeneration. Basic decisions for new generation of gas-liquid solar collectors are developed. Heat-mass-transfer apparatus included in evaporative cooling system, are based on film interaction of flows of gas and liquid and in them, for the creation of nozzle, multi-channel structures from polymeric materials and porous ceramics are used. Preliminary analysis of multifunctional systems possibilities is implemented.

  12. The dry heat exchanger calorimeter system

    A radiometric isothermal heat flow calorimeter and preconditioner system that uses air instead of water as the heat exchange medium has been developed at Mound. The dry heat exchanger calorimeter is 42 inches high by 18 inches in diameter and the preconditioner is a 22 inch cube, making it extremely compact compared to existing units. The new system is ideally suited for transportable, stand-alone, or glovebox applications. Preliminary tests of the system have produced sample measurements with standard deviations less than 0.25% and sample errors less than 0.50%. These tests have shown that the dry heat exchanger system will yield acceptance data with an accuracy comparable to those of Mound water bath systems now in use. 4 figs., 1 tab

  13. Heating, ventilation and air conditioning system modelling

    Whalley, R.; Abdul-Ameer, A. [British University in Dubai (United Arab Emirates)

    2011-03-15

    Heating, ventilation and air conditioning modelling methods, for large scale, spatially dispersed systems are considered. Existing techniques are discussed and proposals for the application of novel analysis approaches are outlined. The use of distributed-lumped parameter procedures enabling the incorporation of the relatively concentrated and significantly dispersed, system element characteristics, is advocated. A dynamic model for a heating, ventilation and air conditioning system comprising inlet and exhaust fans, with air recirculation, heating/cooling and filtration units is presented. Pressure, airflow and temperature predictions within the system are computed following input, disturbance changes and purging operations. The generalised modelling advancements adopted and the applicability of the model for heating, ventilation and air conditioning system simulation, re-configuration and diagnostics is emphasised. The employment of the model for automatic, multivariable controller design purposes is commented upon. (author)

  14. The dry heat exchanger calorimeter system

    This paper reports on a radiometric isothermal heat flow calorimeter and preconditioner system that uses air instead of water as the heat exchange medium which has been developed for use with nuclear material. The dry heat exchanger calorimeter is 42 in. high by 18 in. in diameter and the preconditioner is a 22 in. cube, making it extremely compact compared to existing units. The new system is ideally suited for transportable, stand-alone, or glovebox applications. Preliminary tests of the system have produced sample measurements with standard deviations less than 0.25% and sample errors less than 0.50%. These tests have shown that the dry heat exchanger system will yield acceptable data with an accuracy comparable to those of Mound water bath systems now in use

  15. Application for EURATOM priority support of additional heating for ASDEX Upgrade, phase I and phase II

    In order to reach the full performance plasma parameters of ASDEX Upgrade as provided by the machine technique a heating power of 12 to 15 MW is required. For the minimum required power the appropriate choice for the basic heating system are 6 MW ICRH and 6 MW neutral injection, both with a long pulse capability of up to 10 seconds. ICRH in a frequency range of 30 to 120 MHz shall cover He3 minority, hydrogen fundamental and 2nd harmonic and deuterium 2nd harmonic heating. For neutral injection four JET sources with 60 keV H0 and 80 A combined in one injection box were chosen. The averaged injection angle is 240 to perpendicular at Rsub(O) = 1.7 m. Both systems shall be installed during 1988. The costs are 57.4 MDM for both. (orig./GG)

  16. Evidence for an Additional Heat Source in the Warm Ionized Medium of Galaxies

    Reynolds, R J; Tufte, S L

    1999-01-01

    Spatial variations of the [S II]/H-Alpha and [N II]/H-Alpha line intensity ratios observed in the gaseous halo of the Milky Way and other galaxies are inconsistent with pure photoionization models. They appear to require a supplemental heating mechanism that increases the electron temperature at low densities n_e. This would imply that in addition to photoionization, which has a heating rate per unit volume proportional to n_e^2, there is another source of heat with a rate per unit volume proportional to a lower power of n_e. One possible mechanism is the dissipation of interstellar plasma turbulence, which according to Minter & Spangler (1997) heats the ionized interstellar medium in the Milky Way at a rate ~ 1x10^-25 n_e ergs cm^-3 s^-1. If such a source were present, it would dominate over photoionization heating in regions where n_e < 0.1 cm^-3, producing the observed increases in the [S II]/H-Alpha and [N II]/H-Alpha intensity ratios at large distances from the galactic midplane, as well as accoun...

  17. Rankine cycle waste heat recovery system

    Ernst, Timothy C.; Nelson, Christopher R.

    2016-05-10

    This disclosure relates to a waste heat recovery (WHR) system and to a system and method for regulation of a fluid inventory in a condenser and a receiver of a Rankine cycle WHR system. Such regulation includes the ability to regulate the pressure in a WHR system to control cavitation and energy conversion.

  18. Investigation on Solar Heating System with Building-Integrated Heat Storage

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating and due to storage. The storage affects the heat demand passively due to higher temperatures. Hence heat loss is reduced and passive heating is optioned. In theory, by running the system flow backwards, active heating can...... be self-made to keep the price down. The system is working, but heat exchange from plastic piping to sand is rather poor. The dimensioning of the volume is rather difficult based on common knowledge. Passive heating, hence reduction of heat demand, due to the storage and especially due to the oversized...

  19. LPV Identification of a Heat Distribution System

    Trangbæk, K; Bendtsen, Jan Dimon

    2010-01-01

    This paper deals with incremental system identification of district heating systems to improve control performance. As long as various parameters, e.g. valve settings, are kept fixed, the dynamics of district heating systems can be approximated well by linear models; however, the dynamics change...... significantly when these parameters change. For this reason, we attempt to identify the system using linear parameter varying models. We demonstrate how the so-called ``Hansen Scheme," for linear time-invariant systems, can be employed for incremental identification of linear parameter varying systems as well....... The approach is tested on a laboratory setup emulating a district heating system, where local controllers regulate pumps connected to a common supply. Experiments show that cross-couplings in the system can indeed be identified in closed-loop operation....

  20. Efficiency of insulation passive system of solar heating with transforming flat plate reflector of radiation and accumulator of heat

    Key words: solar radiation, window, reflector of radiation, short-term accumulator of heat, solar heating, insulation passive system, thermal efficiency, heating building. Subjects of research: insulation passive system of solar heating with short-term accumulators of heat, combining the function of collector of solar radiation and hingedly transformed flat plate reflector for additional illumination of heating building and without them. Purpose of work: determination of real possibility of insulation passive system of solar heating with transformed flat plate reflectors of radiation and short-term accumulators of heat and on this basis development of scientific dates for experimental designing and construction of them for natural condition of Uzbekistan. Methods of research: thermal-technical calculation and experiment under natural conditions. The results obtained and their novelty: offered calculation expressions for determining of optimal inclination angle to horizon and coefficient of reflection of direct solar radiation of flat plate reflector with back reflection layer; developed and offered method of calculation of using efficiency of transformed flat plate reflectors of radiation for additional illumination of heating building in the daytime and decreasing of heat losses through window insulation passive systems of solar heating at night; optimized of specific heat of short-time accumulators of heat in insulation passive systems of solar heating; determined real thermal efficiency and replacement coefficient of thermal load to heating of proposed system by the example of operational testing this systems under conditions of Karshi City. Practical value: the results of performed investigations allow to develop the scientific basic dates on designing and marketing on climate conditions in the south of The Republic of Uzbekistan insulation passive systems of solar heating with flat plate reflectors and short-time accumulators of heat, providing to save the

  1. Heat reduction of the MWD telemetry system

    Matviykiv, Taras

    2012-01-01

    In this paper the simplified thermal model of conventional downhole MWD (Measurements While Drilling) telemetry system has been made. The heat reduction methods for the IC (integrated circuits) components of downhole drilling tools have been analyzed.

  2. District heating with SLOWPOKE energy systems

    The SLOWPOKE Energy System, a benign nuclear heat source designed to supply 10 thermal megawatts in the form of hot water for local heating systems in buildings and institutions, is at the forefront of these developments. A demonstration unit has been constructed in Canada and is currently undergoing an extensive test program. Because the nuclear heat source is small, operates at atmospheric pressure, and produces hot water below 100 degrees Celcius, intrinsic safety features will permit minimum operator attention and allow the heat source to be located close to the load and hence to people. In this way, a SLOWPOKE Energy System can be considered much like the oil- or coal-fired furnace it is designed to replace. The low capital investment requirements, coupled with a high degree of localization, even for the first unit, are seen as attractive features for the implementation of SLOWPOKE Energy Systems in many countries

  3. The influence analysis of addition number of plate to heat exchanger performance of TRIGA 2000 reactor

    In order to reduce the existing bubble in the core of Bandung TRIGA 2000 reactor during its operation above 1000 kW, was done by increasing the effectivity of the heat exchanger (HE). One of the methods for increasing this effectivity is done by adding the number of plate to heat exchanger. To get an appropriate number of plate to be added on achieving its requirement, the analysis to know how the comparison of its performance on variation of addition the number of plate, is needed. The analysis was done by using the NTU-Effectivity method. The variables which influence its effectivity was obtained from the operational experiences since of the year 2000 until 2005. Besides that, it was assumed that the properties of working fluid had not much changed on its temperature and its pressure and small fouling deposit on the plate of HE. The results show that generally the addition of the number of plate would increase the effectivity of the heat exchanger. But for the low flow rate of the primary(600 gpm) and the high flow rate of the secondary(6000 gpm), a little bit of increasing effectivity was obtained for the addition the number of plate, and the effectivity had been reached to above 98%. (author)

  4. In situ heat treatment process utilizing a closed loop heating system

    Vinegar, Harold J. (Bellaire, TX); Nguyen, Scott Vinh (Houston, TX)

    2010-12-07

    Systems and methods for an in situ heat treatment process that utilizes a circulation system to heat one or more treatment areas are described herein. The circulation system may use a heated liquid heat transfer fluid that passes through piping in the formation to transfer heat to the formation. In some embodiments, the piping may be positioned in at least two of the wellbores.

  5. Performance improvement of a 330MWe power plant by flue gas heat recovery system

    Xu Changchun; Xu Min; Zhao Ming; Liang Junyu; Sai Juncong; Qiu Yalin; Xiang Wenguo

    2016-01-01

    In a utility boiler, the most heat loss is from the exhaust flue gas. In order to reduce the exhaust flue gas temperature and further boost the plant efficiency, an improved indirect flue gas heat recovery system and an additional economizer system are proposed. The waste heat of flue gas is used for high-pressure condensate regeneration heating. This reduces high pressure steam extraction from steam turbine and more power is generated. The waste heat recov...

  6. Design of biomass district heating systems

    The biomass exploitation takes advantage of the agricultural, forest, and manure residues and in extent, urban and industrial wastes, which under controlled burning conditions, can generate heat and electricity, with limited environmental impacts. Biomass can - significantly - contribute in the energy supplying system, if the engineers will adopt the necessary design changes to the traditional systems and become more familiar with the design details of the biomass heating systems. The aim of this paper is to present a methodology of the design of biomass district heating systems taking into consideration the optimum design of building structure and urban settlement around the plant. The essential energy parameters are presented for the size calculations of a biomass burning-district heating system, as well as for the environmental (i.e. Greenhouse Gas Emissions) and economic evaluation (i.e. selectivity and viability of the relevant investment). Emphasis has been placed upon the technical parameters of the biomass system, the economic details of the boiler, the heating distribution network, the heat exchanger and the Greenhouse Gas Emissions

  7. Design and Evaluation of a Photovoltaic/Thermal-Assisted Heat Pump Water Heating System

    Huan-Liang Tsai

    2014-05-01

    Full Text Available This paper presents the design, modelling and performance evaluation of a photovoltaic/thermal-assisted heat pump water heating (PVTA-HPWH system. The cooling effect of a refrigerant simultaneously enhances the PVT efficiency and effectively improves the coefficient of performance (COP of the HPWH system. The proposed model was built in the MATLAB/Simulink environment by considering the reciprocal energy exchange between a PVT evaporator and a HPWH system. In addition, the power consumption needs of the HPWH are provided by the PV electricity using a model-based control methodology. System performance is evaluated through a real field test. The results have demonstrated the power autarchy of the proposed PVTA-HPWH system with better PVT efficiency and COP. In addition, the good agreement between the model simulation and the experimental measurements demonstrate the proposed model with sufficient confidence.

  8. Ion cyclotron resonance heating system on EAST

    The Ion Cyclotron Resonance Heating (ICRH) system which can provide no less than 10 MW radio frequency (RF) heating power (frequency range from 25 MHz to 100 MHz) is being set up for the experimental advanced superconducting tokamak (EAST) in the institute of plasma physics. System includes High-power and wide-frequency radio amplifier, liquid phase shifter and resonant double loop (RDL) antenna. Now one ICRH system unit whose ultimate output is 2.5 MW has been set up and employed for RF heating experiment and maximum of the injected RF power reached to 200 kW in 2008 EAST tokamak experiment. The results of ICRH heating are satisfying. (author)

  9. Residential solar-heating/cooling system

    1980-01-01

    Report documents progress of residential solar-heating and cooling system development program at 5-month mark of anticipated 17-month program. System design has been completed, and development and component testing has been initiated. Report includes diagrams, operation overview, optimization studies of subcomponents, and marketing plans for system.

  10. Prototype solar heating and cooling systems

    1978-01-01

    A collection of monthly status reports are given on the development of eight prototype solar heating and cooling systems. This effort calls for the development, manufacturing, test, system installation, maintenance, problem resolution, and performance evaluation. The systems are 3-, 25-, and 75-ton size units.

  11. A Freezable Heat Exchanger for Space Suit Radiator Systems

    Nabity, James A.; Mason, Georgia R.; Copeland, Robert J.; Trevino, Luis a.

    2008-01-01

    During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut s metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to space, thus becoming the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the astronaut during an EVA can reduce the amount of expendable water consumed in the sublimator. Radiators have no moving parts and are thus highly reliable. Past freezable radiators have been too heavy, but the weight can be greatly reduced by placing a small and freeze tolerant heat exchanger between the astronaut and radiator, instead of making the very large radiator freeze tolerant. Therefore, the key technological innovation to improve space suit radiator performance was the development of a lightweight and freezable heat exchanger that accommodates the variable heat load generated by the astronaut. Herein, we present the heat transfer performance of a newly designed heat exchanger that endured several freeze / thaw cycles without any apparent damage. The heat exchanger was also able to continuously turn down or turn up the heat rejection to follow the variable load.

  12. The influence of heat accumulation on the surface roughness in powder-bed additive manufacturing

    The influence of heat accumulation on surface roughness during powder-bed additive manufacturing was investigated. A series of Ti-6Al-4V thin plates were produced by using an identical heat input by electron beam melting® (EBM). Spacing distances of 5 mm, 10 mm, and 20 mm were used. The surface roughness of as-built thin plates was measured using a two-axis profilometer. A numerical model was developed to study the influence of spacing distance on heat accumulation. An inverse relationship between the spacing distance and surface roughness was revealed. The experimental and numerical results showed that the surface quality of buildups could be controlled not only by process parameters, but also by the arrangement of components in the buildup chamber. At a constant spacing distance, an increase in the number of powder layers resulted in the accumulation of more heat between the thin plates. An increase in the spacing distance resulted in an upward translation of the Bearing Area Curve (BAC) toward shallower depths, with a reduced core roughness depth (Rk) and peak height (Rpk). A logarithmic regression equation was established from the experimental data. This equation could be used to predict the surface roughness of parts fabricated by EBM® in the studied range of spacing distances. (paper)

  13. Heat Loss Evaluation of the SMART-ITL Primary System

    Ryu, Sung Uk; Bae, Hwang; Kim, Dong Eok; Park, Keun Tae; Park, Hyun Sik; Yi, Sung Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    It is considered that the heat loss rate is one of the critical factors affecting the transient behavior of an integral effect test facility. This paper presents the experimental results of the heat loss rate for the primary system of a SMART-ITL (System-Integrated Modular Advanced ReacTor-Integral Test Loop) facility including the pressurizer (PZR). To evaluate the heat loss rate of the primary system, two different approaches were pursued, i. e., integral and differential approaches. The integral approach is a constant temperature method which controls the core and PZR powers at a desired temperature condition and the differential approach is a natural cooling-down measurement method that lasts for a long period of time. In the present work, the heat losses derived from integral and differential approaches were acquired for the primary system of the SMART-ITL. The results obtained by the two approaches were very similar. In addition, an empirical correlation with respect to the difference between the wall temperature and the ambient temperature was proposed to represent the heat loss characteristics of the SMART-ITL facility. The estimated heat losses could be used to estimate the heat loss during the tests and code simulations.

  14. House owners' perceptions and factors influencing their choice of specific heating systems in Germany

    Against the background of global climate changes and several legal obligations, the target of this paper is to analyze the buying behavior of house owners in Germany with respect to heating systems and the main factors influencing choice when purchasing a specific heating system (e.g., oil heating or wood pellet heating). To investigate these issues, a Germany-wide written survey was conducted and the completed questionnaires of 775 respondents analyzed using multinomial logistic regression. Of 29 different variables influencing the purchase of a heating system, 12 statistically significant variables have been identified which characterize the owners of oil heating, a heat pump, gas heating and wood pellet heating. The membership of different ecological clusters primarily segregates the owners of a specific heating system, but the assessment of the different combustibles also plays a major role in this context. Suppliers of heating systems can use the results of this study to fine-tune their marketing strategies. With respect to policy issues only limited room for additional economic incentives can be identified to promote replacement of fossil-fuel based heating systems in favor of renewable ones. -- Highlights: •Current regulations support renewable heating systems insufficiently in Germany. •We developed a model to characterize the purchasers of different heating systems. •Ecological attitudes differentiate the purchasers of the different heating systems. •Economic reasons are mainly important for owners of gas and oil heating systems

  15. Heat savings in buildings in a 100% renewable heat and power system in Denmark with different shares of district heating

    Zvingilaite, Erika; Balyk, Olexandr

    2014-01-01

    The paper examines implementation of heat saving measures in buildings in 2050, under the assumption that heat and power supply comes solely from renewable resources in Denmark.Balmorel – a linear optimisation model of heat and power sectors in Denmark is used for investigating economically viabl...... penetration of heat savings slightly decreases along with lower capacity investments and system costs.......The paper examines implementation of heat saving measures in buildings in 2050, under the assumption that heat and power supply comes solely from renewable resources in Denmark.Balmorel – a linear optimisation model of heat and power sectors in Denmark is used for investigating economically viable...... levels of heat savings, which can be implemented by reducing heat transmission losses through building elements and by installing ventilation systems with heat recovery, in different future Danish heat and power system scenarios. Today almost 50% of heat demand in Denmark is covered by district heating...

  16. Dual energy use systems: District heating survey

    1980-07-01

    The current status of and problems facing district heating systems operated by electric utilities were identified. The technical and economic factors which can affect the present and future success of district heating systems in the United States were evaluated. A survey of 59 district heating electric utilities was conducted to determine the current status of the industry. Questions developed to obtain data on technical, economic, regulator, and marketing factors were included in the survey. Literature on district heating in the U.S. and abroad was collected from governments, industry and foreign sources and reviewed to aid in evaluating the current and future potential of the industry. Interviews were held with executives of 16 utilities that operate district heating systems in order to determine corporate attitudes. A summary of the literature obtained is provided. Survey results are tabulated and described. The interviews and survey data were used to compile 10 case studies of utilities operating district heating systems under a braod range of circumstances.

  17. Heat transfer and material flow during laser assisted multi-layer additive manufacturing

    A three-dimensional, transient, heat transfer, and fluid flow model is developed for the laser assisted multilayer additive manufacturing process with coaxially fed austenitic stainless steel powder. Heat transfer between the laser beam and the powder particles is considered both during their flight between the nozzle and the growth surface and after they deposit on the surface. The geometry of the build layer obtained from independent experiments is compared with that obtained from the model. The spatial variation of melt geometry, cooling rate, and peak temperatures is examined in various layers. The computed cooling rates and solidification parameters are used to estimate the cell spacings and hardness in various layers of the structure. Good agreement is achieved between the computed geometry, cell spacings, and hardness with the corresponding independent experimental results.

  18. Primary energy savings using heat storage for biomass heating systems

    Mitrović Dejan M.; Janevski Jelena N.; Laković Mirjana S.

    2012-01-01

    District heating is an efficient way to provide heat to residential, tertiary and industrial users. The heat storage unit is an insulated water tank that absorbs surplus heat from the boiler. The stored heat in the heat storage unit makes it possible to heat even when the boiler is not working, thus increasing the heating efficiency. In order to save primary energy (fuel), the boiler operates on nominal load every time it is in operation (for the purpose of this research). The aim of th...

  19. Use of geothermal energy for heating systems

    REZNICHENKO, ARTEM

    2014-01-01

    TFG en intercambio académico. Jade Hochschule (Wilhelmshaven/Oldenburg/Elsfleth) [en] This project makes a study of heat extraction from the soil in order to provide heat to a building. This energy is renewable and clean. Low temperature geothermal energy has very low levels of use. In the last decades, the use of renewable energy is growing exponentially. The biggest part of energy consumption goes to heating systems, that is why the use of geothermal energy can save lots of natural resou...

  20. Project of the solar heating system

    Pořízka, Jaromír

    2008-01-01

    The diploma thesis studies the elaboration of project about thermal solar systém for all- season service. System is used for heating of outdoor pool and in the winter season for the heating of nearby garage in the village Lipůvka. The aim of the work was to make a proportioning, choosing the right parts and calculating the economic and ecologic balance.

  1. Performance analysis of hybrid district heating system

    Mikulandric, Robert; Krajačić, Goran; Khavin, Gennadii;

    2013-01-01

    more extensively used in district heating systems either separately or as a supplement to traditional fossil fuels in order to achieve national energy policy objectives. However, they are still facing problems such as high intermittences, high energy production costs and low load factors as well as...... sources that can complement each other on daily and yearly basis and reduce negative aspects of particular energy source utilisation. In district heating systems, hybridisation could be performed through utilisation of renewable and non-renewable energy sources. Potential of fuel and emission reduction...... could reach up to 20% with utilisation of solar energy as supplement energy source in traditional fossil fuel based district heating systems. In this work, the performance of hybrid district energy system for a particular location will be analysed. For performance analysis, mathematical model that...

  2. Optimising corrosion monitoring in district heating systems

    Hilbert, Lisbeth Rischel; Thorarinsdottir, R.I.; Andersen, A.; Nielsen, Lars Vendelbo

    2002-01-01

    A three-year project - financially supported by the Nordic Industrial Fund - on monitoring of corrosion in district heating systems has been initiated with participation of researchers and industrial partners in Denmark, Finland, Iceland, Norway and Sweden. The primary objective of the project is...... to improve the quality control in district heating systems by corrosion monitoring. In Danish systems electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR), high-sensitive electrical resistance (ER) technology, crevice corrosion probes, as well as weight loss coupons will...

  3. Indoor temperatures for calculating room heat loss and heating capacity of radiant heating systems combined with mechanical ventilation systems

    Wu, Xiaozhou; Olesen, Bjarne W.; Fang, Lei;

    2016-01-01

    In this study, a typical office room with a radiant heating system and a mechanical ventilation system was selected as the research subject. Indoor temperature formulas for calculating the room heat loss (including transmission heat loss and ventilation heat loss) and heating capacity of the hybrid.......0 and 20.3 degrees C and between 19.6 and 20.5 degrees C, respectively, and the indoor temperature for calculating the heating capacity of the hybrid system was between 18.2 and 19.8 degrees C. Accordingly, the relative calculation errors were between 0.3% and 0.5% and between -10.2% and 11.......8% for calculating the transmission heat loss and ventilation heat loss, respectively, and between 16.0% and 17.4% for calculating the heating capacity of the hybrid system. Due to large relative calculation errors, it is necessary to consider the effect of heated surface and cool supply air on indoor temperatures...

  4. Modelling the Size of Seasonal Thermal Storage in the Solar District Heating System

    Giedrė Streckienė; Salomėja Bagdonaitė

    2012-01-01

    The integration of a thermal storage system into the solar heating system enables to increase the use of solar thermal energy in buildings and allows avoiding the mismatch between consumers’ demand and heat production in time. The paper presents modelling a seasonal thermal storage tank various sizes of which have been analyzed in the district solar heating system that could cover a part of heat demand for the district of individual houses in Vilnius. A biomass boiler house, as an additional ...

  5. Exergy Analysis and Second Law Efficiency of a Regenerative Brayton Cycle with Isothermal Heat Addition

    Naser M. Jubeh

    2005-07-01

    Full Text Available Abstract: The effect of two heat additions, rather than one, in a gas turbine engine is analyzed from the second law of thermodynamics point of view. A regenerative Brayton cycle model is used for this study, and compared with other models of Brayton cycle. All fluid friction losses in the compressor and turbine are quantified by an isentropic efficiency term. The effect of pressure ratio, turbine inlet temperature, ambient temperature, altitude, and altitude with variable ambient temperature on irreversibility "exergy destroyed" and second law efficiency was investigated and compared for all models. The results are given graphically with the appropriate discussion and conclusion.

  6. 14 CFR 27.859 - Heating systems.

    2010-01-01

    ...) General. For each heating system that involves the passage of cabin air over, or close to, the exhaust manifold, there must be means to prevent carbon monoxide from entering any cabin or pilot compartment. (b... heater fuel system, fire within the ventilating air passage, or any other heater malfunction, each...

  7. Energy Savings for Solar Heating Systems

    Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

    2004-01-01

    , various simulations of solar heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal system. For some conditions the fuel reduction can be up to the double of the solar...

  8. Demand modelling for central heating systems

    Heller, A.

    2000-07-01

    Most researchers in the field of heat demand estimation have focussed on explaning the load for a given plant based on rather few measurements. This approach is simply the only one adaptable with the very limited data material and limited computer power. This way of dealing with the subject is here called the top-down approach, due to the fact that one tries to explain the load from the overall data. The results of such efforts are discussed in the report, leading to inspiration for own work. Also the significance of the findings to the causes for given heat loads are discussed and summarised. Contrary to the top-down approach applied in literature, a here-called bottom-up approach is applied in this work, describing the causes of a given partial load in detail and combining them to explain the total load for the system. Three partial load 'components' are discussed: 1) Space heating. 2) Hot-Water Consumption. 3) Heat losses in pipe networks. The report is aimed at giving an introduction to these subjects, but at the same time at collecting the previous work done by the author. Space heating is shortly discussed and loads are generated by an advanced simulation model. A hot water consumption model is presented and heat loads, generated by this model, utilised in the overall work. Heat loads due to heat losses in district heating a given a high priority in the current work. Hence a detailed presentation and overview of the subject is given to solar heating experts normally not dealing with district heating. Based on the 'partial' loads generated by the above-mentioned method, an overall load model is built in the computer simulation environment TRNSYS. The final tool is then employed for the generation of time series for heat demand, representing a district heating area. The results are compared to alternative methods for the generation of heat demand profiles. Results form this comparison will be presented. Computerised modelling of systems

  9. Sensitivity of district heating system operation to heat demand reductions and electricity price variations: A Swedish example

    In the future, district heating companies in Sweden must adapt to energy efficiency measures in buildings and variable fuel and electricity prices. Swedish district heating demands are expected to decrease by 1–2% per year and electricity price variations seem to be more unpredictable in the future. A cost-optimisation model of a Swedish local district heating system is constructed using the optimisation modelling tool MODEST. A scenario for heat demand changes due to increased energy efficiency in buildings, combined with the addition of new buildings, is studied along with a sensitivity analysis for electricity price variations. Despite fears that heat demand reductions will decrease co-generation of clean electricity and cause increased global emissions, the results show that anticipated heat demand changes do not increase the studied system's primary energy use or global CO2 emissions. The results further indicate that the heat production plants and the fuels used within the system have crucial importance for the environmental impact of district heat use. Results also show that low seasonal variations in electricity price levels with relatively low winter prices promote the use of electric heat pumps. High winter prices on the other hand promote co-generation of heat and electricity in CHP plants. -- Highlights: ► A MODEST optimisation model of the Uppsala district heating system is built. ► The impact of heat demand change on heat and electricity production is examined. ► An electricity price level sensitivity analysis for district heating is performed. ► Heat demand changes do not increase the primary energy use or global CO2 emissions. ► Low winter prices promote use of electric heat pumps for district heating production.

  10. Use and groundwater risk potential of additives in heat transfer fluids for borehole heat exchangers; Verwendung und Grundwassergefaehrdungspotenzial von Additiven in Waermetraegerfluessigkeiten fuer Erdwaermesonden

    Ilieva, Dafina

    2014-02-25

    Ground based heat exchanger systems need to be evaluated in terms of potential effects on groundwater quality due to the risk of leakage of borehole heat exchanger fluids. The aim of this work was to identify the compounds which are present in additive mixtures and to investigate experimentally their biodegradability and effects on the biodegradation of the major organic component in borehole heat exchanger fluids. A data survey was carried out in cooperation with the State Ministry of the Environment Baden-Wuerttemberg, Germany to collect detailed information about the identity and application amounts of additives in borehole heat exchanger fluids. The survey revealed that numerous additives of various chemical classes and properties are used as corrosion inhibitors, alkalis, dyes, organic solvents, flavors, defoamers and surfactants. Furthermore, it was shown that glycols are among the most often applied antifreeze agents, the main component of the heat exchanger fluids. Based on the prioritization criteria (i) abundance in the borehole heat exchanger fluids, (ii) persistence, and (iii) mobility in the subsurface, the additives benzotriazole, tolyltriazole, 2-ethylhexanoate, benzoate and decane dicarboxylate were selected for further biodegradation experiments. The biodegradation experiments were carried out in batch systems with 60- or 70-m-deep sediments (sandstone or marl) as inoculum. The samples were taken during the installation of borehole heat exchanger systems at two different sites. The microcosms were conducted under oxic, denitrifying, iron- and sulfate-reducing as well as fermentative conditions at the presumed aquifer temperature of 12 C. The major component ethylene glycol was degraded under all conditions studied. The fastest biodegradation occurred under oxic and nitrate-reducing conditions (< 15 days). In all anoxic, nitrate free experiments with marl-sediment fermentation was the predominant process involved in the biodegradation of ethylene

  11. Effects of Si Addition and Heating Ar on the Electromigration Performance of Al-Alloy Interconnects

    Lee, Dok Won; Lee, Byung-Zu; Jeong, Jong Yeul; Park, Hyun; Shim, Kyu Cheol; Kim, Jong Seok; Park, Young Bae; Woo, Sun-Woong; Lee, Jeong-gun

    2002-02-01

    The electromigration (EM) performance of Ti/Al-alloy multilayered metallization with one-step sputtered Al-alloy has been studied. The Al-alloys investigated included Al-1.0%Si-0.5%Cu and Al-0.5%Cu, and the Al-alloy films were prepared with and without heating Ar. The package-level EM test results indicate that the EM resistance of the Al-Si-Cu stack is nearly identical to that of the Al-Cu stack. Si addition was found to degrade the microstructure of the Al-alloy film, while it had the retarding effect on the Ti/Al reaction, which suggests that there exists a trade-off between the film microstructure and the formation of TiAl3 intermetallic compound. The EM performance of the one-step sputtered Al-alloy stack was enhanced by the use of heating Ar during the deposition of Al-alloy film, which has been attributed to the improved microstructure of the Al-alloy film by the use of heating Ar.

  12. Test report - caustic addition system operability test procedure

    This Operability Test Report documents the test results of test procedure WHC-SD-WM-OTP-167 ''Caustic Addition System Operability Test Procedure''. The Objective of the test was to verify the operability of the 241-AN-107 Caustic Addition System. The objective of the test was met

  13. Additive impacts on particle emissions from heating low emitting cooking oils

    Amouei Torkmahalleh, M.; Zhao, Y.; Hopke, P. K.; Rossner, A.; Ferro, A. R.

    2013-08-01

    The effect of five additives, including table salt, sea salt, black pepper, garlic powder, and turmeric, on the emission of PM2.5 and ultrafine particles (UFP) from heated cooking oil (200 °C) were studied. One hundred milligrams of the additives were added individually to either canola or soybean oil without stirring. Black pepper, table salt, and sea salt reduced the PM2.5 emission of canola oil by 86% (p Turmeric and garlic powder showed no changes in the PM2.5 and total number emissions of canola oil. Table salt and sea salt, decreased the level of PM2.5 emissions from soybean oil by 47% (p Turmeric and garlic powder had no effect on soybean oil with respect to total particle number emissions. Our results indicate that table salt, sea salt, and black pepper can be used to reduce the particle total number and PM2.5 emissions when cooking with oil.

  14. House-internal heating systems; Husinterna vaermesystem

    Johansson, Per-Olof; Wollerstrand, Janusz [Lund Univ. (Sweden). Dept. of Heat and Power Engineering

    2005-07-01

    In this report the placement of the circulation-pump in of waterborne radiator systems, as well as their filling and deairation are investigated. The study was done by literature studies and interviews with consultants and companies active on the HVAC-market. It was concluded that different placements of the pump in relationship to the heat exchanger exist, and the arguments for the choice of placement are varying. The main explanation of the choice of placement is that it is based on experience/or by practical reasons. The most important factor influencing the placement of the pump found, was how the pump is situated in relation to the expansion-tank. To maintain pressure in the whole system the expansion-tank should be placed on the suction side of the pump without any intermediate pressure-dropping devices in between. This placement ensures overpressure in the whole radiator-system and reduces the risk of unwanted leak in of air. To avoid cavitation sufficient static pressure on the suction side of the pump is necessary. The pressure increases with the temperature, which must be taken into consideration if the pump is placed on the warm side of the heat-exchanger. From this point of view a placement in the return-pipe from the radiator-system is to be preferred. Before advices for HVAC-branch regarding placement of the circulation-pump in the heating systems can be implemented, it is of big importance to analyse and clearly specify the advantages and disadvantages of a certain placement of the pump. There is a need of directions to get house-internal systems to operate properly together with district heating system. This is especially important when older heating systems with burners and shunt valves are being connected. Filling and deairation of the radiator system is of great importance for the function of the system. A radiator-system with significant level of air remains is difficult to adjust and will not work properly. Air in the radiators leads to

  15. Creep of heat treated silicon nitride with neodymium and yttrium oxides additions

    Research highlights: → In all cases, microstructural examination of crept samples showed that existing phases at grain boundaries were associated to the deformation processes. This highlights the importance of the presence and the amount of grain boundary glass. → Crystallization of the remnant phase during heat treatment in nitrogen atmosphere gives rise to further crystallization of the new phases in the Nd-Si-O-N system such as Nd4Si3O12 and Nd2Si3O3N4. A consequence of this crystallization is a significant reduction in stress exponents and creep rates for the heat treated samples. → Diffusional creep may prevail for lower temperatures, low glass content and stresses. Cavitation would start to operate and become increasingly prevalent with increase in stress, temperature and decrease in crystallinity of the grain boundary phase. - Abstract: At the present work, samples of silicon nitride with 12 wt% of yttrium/neodymium oxides mixture were formed by gas-pressure sintering. Pos sintering heat treatments in nitrogen with a stepwise temperature variation were performed in some samples. The short term compressive creep tests were undertaken in an argon atmosphere, over a stress range of 50-300 MPa and temperature range of 1200-1400 deg. C. Values of stress exponents near unity for (i) low temperature testing in all materials and (ii) all temperatures for heat treated samples suggest diffusion accommodation processes, involving ambipolar diffusion of ionic species in the grain boundary phases. Crystallization of the remnant phase during heat treatment in a nitrogen atmosphere gives rise to further formation of new phases in the Nd-Si-O-N system such as Nd4Si3O12 and Nd2Si3O3N4. A consequence of this crystallization is a significant reduction in stress exponents and creep rates for the heat treated samples. The wedge crack observed after creep testing at specimens in its as-sintered condition may be related to the increased probability of cavitation in the

  16. Creep of heat treated silicon nitride with neodymium and yttrium oxides additions

    Moreira da Silva, Cosme Roberto, E-mail: cosmeroberto@gmail.com [Universidade de Brasilia, UNB, Brasilia-DF 70910-900 (Brazil); Aparecida Pereira Reis, Danieli [Instituto Tecnologico de Aeronautica - Sao Jose dos Campos CEP (Brazil); Santos, Claudinei dos [Faculdade de Engenharia Quimica de Lorena, DEMAR, Lorena 12600-000 (Brazil)

    2010-10-15

    Research highlights: {yields} In all cases, microstructural examination of crept samples showed that existing phases at grain boundaries were associated to the deformation processes. This highlights the importance of the presence and the amount of grain boundary glass. {yields} Crystallization of the remnant phase during heat treatment in nitrogen atmosphere gives rise to further crystallization of the new phases in the Nd-Si-O-N system such as Nd{sub 4}Si{sub 3}O{sub 12} and Nd{sub 2}Si{sub 3}O{sub 3}N{sub 4}. A consequence of this crystallization is a significant reduction in stress exponents and creep rates for the heat treated samples. {yields} Diffusional creep may prevail for lower temperatures, low glass content and stresses. Cavitation would start to operate and become increasingly prevalent with increase in stress, temperature and decrease in crystallinity of the grain boundary phase. - Abstract: At the present work, samples of silicon nitride with 12 wt% of yttrium/neodymium oxides mixture were formed by gas-pressure sintering. Pos sintering heat treatments in nitrogen with a stepwise temperature variation were performed in some samples. The short term compressive creep tests were undertaken in an argon atmosphere, over a stress range of 50-300 MPa and temperature range of 1200-1400 deg. C. Values of stress exponents near unity for (i) low temperature testing in all materials and (ii) all temperatures for heat treated samples suggest diffusion accommodation processes, involving ambipolar diffusion of ionic species in the grain boundary phases. Crystallization of the remnant phase during heat treatment in a nitrogen atmosphere gives rise to further formation of new phases in the Nd-Si-O-N system such as Nd{sub 4}Si{sub 3}O{sub 12} and Nd{sub 2}Si{sub 3}O{sub 3}N{sub 4}. A consequence of this crystallization is a significant reduction in stress exponents and creep rates for the heat treated samples. The wedge crack observed after creep testing at specimens

  17. One—Dimensional Analysis of Thermal Choking in Case of Heat Addition in Ducts

    YoshiakiMiyazato; MasashiKashitani; 等

    2000-01-01

    The thermal choking phenomenon is of great importance in an inlet isolator in dual-mode ram jet/scramjet combustor.In some cases the choked flow creates a pseudo-shock wave including a shock train in it at the engine inlet and causes large amounts of drag and radically reduces the performance of the engine at high flight Mach numbers,The present paper describes a one-dimensional flow model taking account of the upstream boundary-layer as well as heat addition by using a mass-weighted averaging technique.The simple relationships for the flow field in a constant area duct in which the effect of the usptream boundary-layer is considered but the effect of the wall friction in the duct can be neglected are presented.The results of the calculation such as the maximum heat addition when the thermal choking occurs,the downstream Mach number and the static pressure ratio are presented and examined in detail.

  18. IMPROVEMENT OF TYPE IV CRACKING RESISTANCE OF 9Cr HEAT RESISTING STEEL WELDMENT BY BORON ADDITION

    M.Tabuchi; M.Kondo; T.Watanabe; H.Hongo; F.Yin; F.Abe

    2004-01-01

    Creep lives of high Cr ferritic heat resisting steel weldments decrease due to Type IV fracture, which occurs as a result of formation and growth of creep voids and cracks on grain boundaries in fine-grained heat affected zone (HAZ). Because boron is considered to suppress the coarsening of grain boundary precipitates and growth of creep voids, we have investigated the effect of boron addition on the creep properties of 9Cr steel weldments. Four kinds of 9Cr3W3CoVNb steels with boron content varying from 4.7×10-5 to 1.8×10-4 and with nitrogen as low as 2.0×10-5 were prepared.The steel plates were welded by gas tungsten arc welding and crept at 923K. It was found that the microstructures of HAZ were quite different from those of conventional high Cr steels such as P91 and P92, namely the fine-grained HAZ did not exist in the present steel weldments. Boron addition also has the effect to suppress coarsening of grain boundary carbides in HAZ during creep. As a result of these phenomena,the welded joints of present steels showed no Type IV fractures and much better creep lives than those of conventional steels.

  19. Primary energy savings using heat storage for biomass heating systems

    Mitrović Dejan M.

    2012-01-01

    Full Text Available District heating is an efficient way to provide heat to residential, tertiary and industrial users. The heat storage unit is an insulated water tank that absorbs surplus heat from the boiler. The stored heat in the heat storage unit makes it possible to heat even when the boiler is not working, thus increasing the heating efficiency. In order to save primary energy (fuel, the boiler operates on nominal load every time it is in operation (for the purpose of this research. The aim of this paper is to analyze the water temperature variation in the heat storage, depending on the heat load and the heat storage volume. Heat load is calculated for three reference days, with average daily temperatures from -5 to 5°C. The primary energy savings are also calculated for those days in the case of using heat storage in district heating.[Projekat Ministarstva nauke Republike Srbije, br. TR 33051: The concept of sustainable energy supply of settlements with energy efficient buildings

  20. Heat flux dynamics in dissipative cascaded systems

    de Lorenzo, S.; Farace, A.; Ciccarello, F.; De Palma, G; Giovannetti, V.

    2014-01-01

    We study the dynamics of heat flux in the thermalization process of a pair of identical quantum system that interact dissipatively with a reservoir in a {\\it cascaded} fashion. Despite the open dynamics of the bipartite system S is globally Lindbladian, one of the subsystems "sees" the reservoir in a state modified by the interaction with the other subsystem and hence it undergoes a non-Markovian dynamics. As a consequence, the heat flow exhibits a non-exponential time behaviour which can gre...

  1. A simplified heat pump model for use in solar plus heat pump system simulation studies

    Perers, Bengt; Andersen, Elsa; Nordman, Roger; Kovacs, Peter

    2012-01-01

    Solar plus heat pump systems are often very complex in design, with sometimes special heat pump arrangements and control. Therefore detailed heat pump models can give very slow system simulations and still not so accurate results compared to real heat pump performance in a system. The idea here is...

  2. Design software for solar water heating systems

    Zheng Ruicheng; Li Zhong; He Tao; Zhange Xinyu; Feng Airong; Sun Zhifeng [Inst. of Air Conditioning, China Academy of Building Research, BJ (China)

    2008-07-01

    It is introduced that the ''Design Software for Solar Water Heating Systems'' which is the first design software suitable to China's weather condition and product's performance in the paper. The software developed by IAC, CABR independently and has CABR own knowledge property right. There are three databases and four function modules in the software and the capacity of the software is both of system design and system effect analysis. (orig.)

  3. Case Studies in Low-Energy District Heating Systems: Determination of Dimensioning Methods for Planning the Future Heating Infrastructure

    Tol, Hakan; Nielsen, Susanne Balslev; Svendsen, Svend

    The climate crisis and the new technological possibilities for building low energy buildings give the opportunity to improve the municipal heating systems. The heating demand will be less in the future and renewable energy has to be integrated in the design of district heating systems. The paper...... future’s sustainable and energy efficient heating infrastructure. In this paper, a case study which focuses on dimensioning method of piping network of low-energy DH system in a new settlement, located in Roskilde Municipality, Denmark, is presented. In addition to the developed dimensioning method......, results about the optimal network layout and substation type for low-energy DH systems are also pointed out regarding to this case study. A second case study, included in this paper, focuses on technical and economical aspects of replacing natural gas heating system to low-energy DH system in an existing...

  4. Assessment of dynamic energy conversion systems for radioisotope heat sources

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 7450C, and case III with a BOL source temperature of 9450C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of 238Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass

  5. Developing the Mathematical Model of Regenerative Heat Exchangers for Energy and Heat Supply Systems of High Temperature Heat Process Units

    Кошельник, Александр Вадимович; Лавинский, Денис Владимирович; Хавин, Евгений Валерьевич; Павлова, Виктория Геннадиевна; Гордиенко, Елена Петровна

    2015-01-01

    A mathematical model for the computation of the heat exchange in the heat accumulation elements of the regenerative heat exchangers of energy and heat supply systems for high temperature heat process units has been presented. The model allows us to obtain the design data about the operation parameters of the regenerators, nozzle temperature state, and a change in heat carrier parameters. The obtained data can be used for the selection of structural and mode-related parameters for the regenera...

  6. Additive Units of Product System of Hilbert Modules

    Biljana Vujosevic

    2016-03-01

    Full Text Available In this paper we consider the notion of additive units and roots of a central unital unit in a spatial product system of two-sided Hilbert C∗-modules. This is a generalization of the notion of additive units and roots of a unit in a spatial product system of Hilbert spaces introduced in [B. V. R. Bhat, M. Lindsay, M. Mukherjee, Additive units of product system, arXiv:1501.07675v1 [math.FA] 30 Jan 2015]. We introduce the notion of continuous additive unit and continuous root of a central unital unit ω in a spatial product system over C∗-algebra B and prove that the set of all continuous additive units of ω can be endowed with a structure of two-sided Hilbert B − B module wherein the set of all continuous roots of ω is a Hilbert B − B submodule.

  7. Analysis and Interpretation of the Plasma Dynamic Response to Additional Heating Power using different Diagnostics

    The main goal in the research of nuclear fusion, and therefore in tokamak research as well, is the development of a high power, steady-state power plant. To obtain the high power required for igniting the plasma, the size of the device must be very large. The performance of the tokamak plasma depends in particular on the plasma shape and on the internal plasma profiles. These profiles include those of the current density and the pressure, two quantities that can be modified by means of auxiliary heating methods such as Electron Cyclotron Heating (ECH). ECH is a very important tool due to its capability of injecting highly localised and intense power. Off-axis ECH and Electron Cyclotron Current Drive (ECCD) modify both current density and electron temperature profiles, leading to modification of confinement and stability properties. in particular, complete stabilisation of magnetohydrodynamic modes using ECCD is feasible. Furthermore, ECH is crucial as a mean of increasing the bootstrap current fraction through the formation of internal transport barriers, so that confinement is also improved. Finally, it is also noted that modulated ECH (MECH) is a very effective tool for perturbative energy transport experiments in many different regimes. Experiments performed in the TCV and the ASDEX Upgrade tokamaks are presented. The role of TCV is very important due to its flexibility of varying the plasma shape, its versatile high power ECH system at both the second and third electron cyclotron harmonics, and due to the numerous diagnostics installed, e.g. the two soft X-ray (SXR) diagnostics which simultaneously allow high temporal and spatial resolutions. The importance of ASDEX Upgrade is related to its large size, which makes it a reactor-relevant experimental facility, and to the Neutral Beam Injection (NBI) and ECH heating facilities, which allow a study of heat and particle transport in either mostly ion-heated or mostly electron-heated regimes. Moreover, for the

  8. Analysis and Interpretation of the Plasma Dynamic Response to Additional Heating Power using different Diagnostics

    Manini, A

    2002-07-01

    The main goal in the research of nuclear fusion, and therefore in tokamak research as well, is the development of a high power, steady-state power plant. To obtain the high power required for igniting the plasma, the size of the device must be very large. The performance of the tokamak plasma depends in particular on the plasma shape and on the internal plasma profiles. These profiles include those of the current density and the pressure, two quantities that can be modified by means of auxiliary heating methods such as Electron Cyclotron Heating (ECH). ECH is a very important tool due to its capability of injecting highly localised and intense power. Off-axis ECH and Electron Cyclotron Current Drive (ECCD) modify both current density and electron temperature profiles, leading to modification of confinement and stability properties. in particular, complete stabilisation of magnetohydrodynamic modes using ECCD is feasible. Furthermore, ECH is crucial as a mean of increasing the bootstrap current fraction through the formation of internal transport barriers, so that confinement is also improved. Finally, it is also noted that modulated ECH (MECH) is a very effective tool for perturbative energy transport experiments in many different regimes. Experiments performed in the TCV and the ASDEX Upgrade tokamaks are presented. The role of TCV is very important due to its flexibility of varying the plasma shape, its versatile high power ECH system at both the second and third electron cyclotron harmonics, and due to the numerous diagnostics installed, e.g. the two soft X-ray (SXR) diagnostics which simultaneously allow high temporal and spatial resolutions. The importance of ASDEX Upgrade is related to its large size, which makes it a reactor-relevant experimental facility, and to the Neutral Beam Injection (NBI) and ECH heating facilities, which allow a study of heat and particle transport in either mostly ion-heated or mostly electron-heated regimes. Moreover, for the

  9. Design of A District Heating System Including The Upgrading of Residual Industrial Waste Heat

    Falcao, P.W.; Mesbah, A.; Suherman, M.V.; Wennekes, S.

    2005-01-01

    This study was aimed to evaluate the feasibility of using a waste heat stream from DSM for a District Heating System. A conceptual design was carried out with emphasis on the unit for upgrading the residual waste heat. Having reviewed heat pump technology, mechanical heat pump was found to be the be

  10. Heat-Flux Gage thermophosphor system

    Tobin, K.W.

    1991-08-01

    This document describes the installation, hardware requirements, and application of the Heat-Flux Gage (Version 1.0) software package developed by the Oak Ridge National Laboratory, Applied Technology Division. The developed software is a single component of a thermographic phosphor-based temperature and heat-flux measurement system. The heat-flux transducer was developed by EG G Energy Measurements Systems and consists of a 1- by 1-in. polymethylpentene sheet coated on the front and back with a repeating thermographic phosphor pattern. The phosphor chosen for this application is gadolinium oxysulphide doped with terbium. This compound has a sensitive temperature response from 10 to 65.6{degree}C (50--150{degree}F) for the 415- and 490-nm spectral emission lines. 3 refs., 17 figs.

  11. Solar water heating systems : a buyer's guide

    Noble, M. [EnerWorks, London, ON (Canada)

    2000-07-01

    The basic operation of domestic solar water heaters was described to inform consumers about the various types currently available on the market and to assist them in choosing a product for residential needs. In addition to reducing energy costs by 50 per cent compared to conventional water heaters, their use minimizes greenhouse gas emissions. A typical unit, which can be easily retrofitted to an existing system for year-round or seasonal use, consists of a solar collector mounted on a roof where sunlight passes through an absorbing material and is converted into heat. It also includes a pump which circulates heat transfer fluid, a heat exchanger, and storage tanks. Dealers recognized by the Canadian Solar Industries Association and the Solar Energy Society of Canada can recommend qualified installers who comply with CSA standards. The primary factors which determine energy conservation are routine maintenance, the size of the collector, appliance efficiency, amount of sunlight and amount of water consumed. Laundering during the day, installing low-flow showerheads, insulating pipes, and using tepid water for laundry can further reduce energy costs. Solar energy can also be used for residential pool heating, passive and active solar space heating and photovoltaic systems which are commonly used in remote off-grid areas. A simple method to calculate annual dollar saving from a solar water heating system was included with this guide along with a glossary, a reader survey and a list of sources for more information on solar energy. 2 tabs., 11 figs.

  12. Dynamic behavior of district heating systems

    The goal of this study is to develop a simulation model of a hot water system taking into account the time dependent phenomena which are important for the operational management of such a system. A state of the art literature review has shown that there is no such model considering all parts from the generation of the heat at the plant to its consumption in the connected buildings so far. First, an exhaustive list of all dynamic phenomena occurring in district heating systems has been drawn and analyzed. Considering this list, this thesis proposes that a model which satisfies the criteria listed above can be developed by superposing four sub-models which are a dynamic model of the heat generation plant, a steady state model of the hydraulic calculation of the distribution network, a dynamic model of the thermal behavior of the network and a dynamic model of the heat consumers. The development of the four sub-models starts from the fundamental conservation equations for fluid systems, i.e. the conservation of mass, momentum and energy. The transformations of those general equations into simple calculation formulas show and justify the hypotheses made in the modeling process. The heat generation plant model itself is a set of sub-models: the models for steam boilers, hot water boilers and heat accumulators which take account of the dynamic evolution of the water temperature by a simple form of the energy conservation equation, as well as the steady state models for circulation pumps and pressurizers. Since the velocities in the network pipes are small, a consideration of steady states is adopted. A network model allowing to calculate the hydraulic variables in every point is adopted from the graph theory. The pressures and flow rates in the network are calculated at discrete time steps and they are considered to be constant for the duration between the time steps. (author) figs., tabs., refs

  13. Geometric principles in additive systems for construction of vaults

    Jaeger, Thomas Arvid

    2015-01-01

    and the reinforced concrete made new large spans possible. These was in-situ casted and not additive systems. Utzon’s Sydney opera house from the mid-fifties combined the additive system, iron reinforcement and concrete into at new prefabricated vault system, which could handle the complex geometry of...... are at last compared to principles of joining elements in other materials. Keywords: Vaults, additive systems, shells, complex geometry, basic geometric principles....... della Fiore. The Barouque style followed with the domes of Borromini; Bernini and Guarini. The Period of Enlightenment had iconic tunnel- and dome vault projects by Etienne l. Boulée. All these stone vaults were made by additive systems in bricks and mortar. In the 20.th century concrete was introduced...

  14. Design and operation of the power installation for the TCV ECR additional heating

    Following a brief introduction to the TCV project, this paper concentrates on the Regulated High Voltage Power Supply (RHVPS) system chosen to supply the nine gyrotrons, distributed in three clusters, that will deliver 4.5 MW of Electron Cyclotron Resonance Heating (ECRH) to TCV plasmas. The configuration of these clusters is described in some detail, including the results of site test both with dummy load (80 kV, 85 A, 2 sec) and the gyrotrons themselves (70 kV, 25 A, 2 sec). Some details are also given of gyrotron auxiliaries, interlock circuitry, control and data acquisition, and integration into TCV control environment. (author) 4 figs., 1 tab., 4 refs

  15. Energy Integrated Lighting-Heating-Cooling System.

    Meckler, Gershon; And Others

    1964-01-01

    Energy balance problems in the design of office buildings are analyzed. Through the use of integrated systems utilizing dual purpose products, a controlled environment with minimum expenditure of energy, equipment and space can be provided. Contents include--(1) office building occupancy loads, (2) office building heating load analysis, (3) office…

  16. Graphene Platelets as Morphology Tailoring Additive in Carbon Nanotube Transparent and Flexible Electrodes for Heating Applications

    Grzegorz Wroblewski

    2015-01-01

    Full Text Available Flexible and transparent electrodes were fabricated with spray coating technique from paints based on multiwalled carbon nanotubes with the addition of graphene platelets. The work presents the influence of graphene platelets on the paints rheology and layers morphology, which has a strong connection to the electrooptical parameters of the electrodes. The paints rheology affects the atomization during spray coating and later the leveling of the coating on the substrate. Both technological aspects shape the morphology of the electrode and the distribution of nanoparticles in the coating. All these factors influence the sheet resistance and roughness, which is linked to the optical transmission and absorbance. In our research the electrode was applied as a transparent and elastic heating element with 68% optical transmission at 550 nm wavelength and 8.4 kΩ/□ sheet resistance. The elastic heating element was tested with a thermal camera at the 3 diverse supply voltages −20, 30, and 60 VDC. The test successfully confirmed and supported our proposed uses of elaborated electrodes.

  17. Corrosion Rate Monitoring in District Heating Systems

    Hilbert, Lisbeth Rischel; Nielsen, Lars Vendelbo; Andersen, A.

    2005-01-01

    Quality control in district heating systems to keep uniform corrosion rates low and localized corrosion minimal is based on water quality control. Side-stream units equipped with carbon steel probes for online monitoring were mounted in district heating plants to investigate which techniques would...... measurements was too long for real time data, and reliable mass loss data could only be obtained after 6 months exposure. It was furthermore found that localized corrosion events detected by the carbon steel crevice corrosion cell correlated with oxygen peaks of even a few hours duration....

  18. Field Measurements of Heating System Efficiency in Nine Electrically-Heated Manufactured Homes.

    Davis, Bob; Siegel, J.; Palmiter, L.; Baylon, D.

    1996-07-01

    This report presents the results of field measurements of heating efficiency performed on nine manufactured homes sited in the Pacific Northwest. The testing procedure collects real-time data on heating system energy use and heating zone temperatures, allowing direct calculation of heating system efficiency.

  19. A heat receiver design for solar dynamic space power systems

    Baker, Karl W.; Dustin, Miles O.; Crane, Roger

    1990-01-01

    An advanced heat pipe receiver designed for a solar dynamic space power system is described. The power system consists of a solar concentrator, solar heat receiver, Stirling heat engine, linear alternator and waste heat radiator. The solar concentrator focuses the sun's energy into a heat receiver. The engine and alternator convert a portion of this energy to electric power and the remaining heat is rejected by a waste heat radiator. Primary liquid metal heat pipes transport heat energy to the Stirling engine. Thermal energy storage allows this power system to operate during the shade portion of an orbit. Lithium fluoride/calcium fluoride eutectic is the thermal energy storage material. Thermal energy storage canisters are attached to the midsection of each heat pipe. The primary heat pipes pass through a secondary vapor cavity heat pipe near the engine and receiver interface. The secondary vapor cavity heat pipe serves three important functions. First, it smooths out hot spots in the solar cavity and provides even distribution of heat to the engine. Second, the event of a heat pipe failure, the secondary heat pipe cavity can efficiently transfer heat from other operating primary heat pipes to the engine heat exchanger of the defunct heat pipe. Third, the secondary heat pipe vapor cavity reduces temperature drops caused by heat flow into the engine. This unique design provides a high level of reliability and performance.

  20. Characterization of a solar photovoltaic/loop-heat-pipe heat pump water heating system

    Highlights: ► Describing concept and operating principle of the PV/LHP heat pump water heating system. ► Developing a numerical model to evaluate the performance of the system. ► Experimental testing of the prototype system. ► Characterizing the system performance using parallel comparison between the modelling and experimental results. ► Investigating the impact of the operating conditions to the system’s performance. -- Abstract: This paper introduced the concept, potential application and benefits relating to a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for hot water generation. On this basis, the paper reported the process and results of characterizing the performance of such a system, which was undertaken through dedicated thermo-fluid and energy balance analyses, computer model development and operation, and experimental verification and modification. The fundamental heat transfer, fluid flow and photovoltaic governing equations were applied to characterize the energy conversion and transfer processes occurring in each part and whole system layout; while the energy balance approach was utilized to enable inter-connection and resolution of the grouped equations. As a result, a dedicated computer model was developed and used to calculate the operational parameters, optimise the geometrical configurations and sizes, and recommend the appropriate operational condition relating to the system. Further, an experimental rig was constructed and utilized to acquire the relevant measurement data that thus enabled the parallel comparison between the simulation and experiment. It is concluded that the testing and modelling results are in good agreement, indicating that the model has the reasonable accuracy in predicting the system’s performance. Under the given experimental conditions, the electrical, thermal and overall efficiency of the PV/LHP module were around 10%, 40% and 50% respectively; whilst the system’s overall performance

  1. Heat storage in solar thermal systems

    Sedmidubský, Petr

    2014-01-01

    This bachelor´s thesis deals with heat storage in solar thermal systems. The first part of the thesis is devoted to the solar energy. The problems with its use are described in this part. The second part is devoted to solar thermal systems. Various types and designs of solar thermal systems are described in this part. The third part of thesis is devoted to the various types of solar thermal systems. The principle of their operation, advantages, disadvantages and the possibility of their pract...

  2. Nonlinear feedback in a six-dimensional Lorenz model: impact of an additional heating term

    Shen, B.-W.

    2015-12-01

    In this study, a six-dimensional Lorenz model (6DLM) is derived, based on a recent study using a five-dimensional (5-D) Lorenz model (LM), in order to examine the impact of an additional mode and its accompanying heating term on solution stability. The new mode added to improve the representation of the streamfunction is referred to as a secondary streamfunction mode, while the two additional modes, which appear in both the 6DLM and 5DLM but not in the original LM, are referred to as secondary temperature modes. Two energy conservation relationships of the 6DLM are first derived in the dissipationless limit. The impact of three additional modes on solution stability is examined by comparing numerical solutions and ensemble Lyapunov exponents of the 6DLM and 5DLM as well as the original LM. For the onset of chaos, the critical value of the normalized Rayleigh number (rc) is determined to be 41.1. The critical value is larger than that in the 3DLM (rc ~ 24.74), but slightly smaller than the one in the 5DLM (rc ~ 42.9). A stability analysis and numerical experiments obtained using generalized LMs, with or without simplifications, suggest the following: (1) negative nonlinear feedback in association with the secondary temperature modes, as first identified using the 5DLM, plays a dominant role in providing feedback for improving the solution's stability of the 6DLM, (2) the additional heating term in association with the secondary streamfunction mode may destabilize the solution, and (3) overall feedback due to the secondary streamfunction mode is much smaller than the feedback due to the secondary temperature modes; therefore, the critical Rayleigh number of the 6DLM is comparable to that of the 5DLM. The 5DLM and 6DLM collectively suggest different roles for small-scale processes (i.e., stabilization vs. destabilization), consistent with the following statement by Lorenz (1972): "If the flap of a butterfly's wings can be instrumental in generating a tornado, it can

  3. 46 CFR 153.430 - Heat transfer systems; general.

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Heat transfer systems; general. 153.430 Section 153.430... Temperature Control Systems § 153.430 Heat transfer systems; general. Each cargo cooling system required by... separated from all other cooling and heating systems; and (c) Allow manual regulation of the system's...

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

    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....

  5. Solar heating and cooling systems design and development

    1977-01-01

    The development and delivery of eight prototype solar heating and cooling systems for installation and operational test was reported. Two heating and six heating and cooling units will be delivered for single family residences, multiple family residences and commercial applications.

  6. A comparison of the heat and mechanical energy of a heat-pump wind turbine system

    Aybek, A.; Arslan, S.; Yildiz, E.; Atik, K. [University of Kahramanmaras (Turkey). Dept. of Agricultural Machinery

    2000-07-01

    While a variety of applications of wind energy have been studied in Turkey, no significant efforts have been made to utilize heat pumps for heat generation. The use of heat pumps in wind energy systems is worth considering because of the high efficiency of heat production. In this study, a directly coupled wind turbine-heat pump system was designed, constructed, and tested. Measurements determined the mechanical energy of the rotors of the wind turbine and the heat energy generated by the heat pump driven by the rotor shaft. Based on the comparisons between the power generated by the heat pump and the power of the Savonius rotors, it was found that the heat energy gained by the heat pump was four times greater than the mechanical energy obtained from the turbine. It was suggested that heat pumps could be efficiently used in wind energy systems. (Author)

  7. A study on the design and analysis of a heat pump heating system using wastewater as a heat source

    Baek, N.C. [Korea Institute of Energy, Daejeon (Korea). Solar Thermal Research Center; Shin, U.C. [Daejeon University (Korea); Yoon, J.H. [Hanbat University, Daejeon (Korea)

    2005-03-01

    In this study, the compression heat pump system using wastewater, as a heat source, from hotel with sauna was designed and analyzed. This study was performed to investigate the feasibility of the wastewater use for heat pump as a heat source and to obtain engineering data for system design. This heat pump system uses off-peak electricity that is a cheap energy compared to fossil fuel in Korea. For this, the charging process of heat into the hot water storage tank is achieved only at night time (22:00-08:00). TRNSYS was used for the system simulation with some new components like the heat pump, which we create ourselves. As a result, it was forecasted that the yearly mean COP of heat pump is about 4.8 and heat pump can supply 100% of hot water load except weekend of winter season. The important thing that should be considered for the system design is to decrease the temperature difference between condenser and evaporator working fluids during the heat charging process by the heat pump. This heat pump system using wastewater from sauna, public bath, building, etc. can therefore be effectively applied not only for water heating but also space heating and cooling in regions like as Korea. (author)

  8. Modelling of the heating system for a building

    The district-heating systems for the heat-energy supply to the building consume substantial resources and the possibility to analyse the behaviour of the building as a part of the system is very important. The dynamic modelling of such a system may be simplified by using modelling software, such as MatLab. The model of the heat flows in the building and in the heating system and domestic water-heating system with heat-energy controllers has been developed. The model is based on the different equations of the heat flows between the elements of the building

  9. 40 CFR 63.104 - Heat exchange system requirements.

    2010-07-01

    ... heat exchange system or at locations where the cooling water enters and exits each heat exchanger or... manufacturing process units. (iii) For samples taken at the entrance and exit of each heat exchanger or any... cooling water enters the individual heat exchanger or group of heat exchangers and the exit is the...

  10. HEAT PIPE RADIATIVE COOLING SYSTEMS FOR SPACE OPTICAL SENSORS

    Baturkin, Volodya

    2007-01-01

    The heat pipes application in passive radiative cooling system is considered on the base of the analysis of thermal balance of consecutive thermal elements in system „Sensor - heat pipe – radiator-space“. This analysis defines the points of main thermal attention – heat leakage from mounting place, heat exchange with external radiative surrounding, minimization of thermal resistance of conductors and interaction between these factors. The secularities of heat pipe application as a heat tra...

  11. CHF enhancement in pool boiling system with additives under atmospheric pressure

    In this study, CHF behavior on a small SS304 plate (200 x 50 x 1 mm) at varying inclination angle of the heated surface under atmospheric pressure was studied in pool boiling system with distilled water or several additive solutions. Four fluids, including distilled water, were used to investigate the effect of each additive on CHF at given condition, which were distilled water, boric acid solution (2000, 4000 ppm), TSP (Tri-sodium phosphate) solution (2000, 5000 ppm). All additives showed CHF enhancement effect in comparison with distilled water. The orientation angle was ranged from 5 degrees (near downward facing position) to 90 degrees (vertical position). CHF was increased with the increase of the tilting angle. For the reason of the enhancement with additives, change of heated surface characteristic was discussed. Contact angle was measured, and change of this surface characteristic was discussed as the dominant factor for the enhancement of CHF. (authors)

  12. Performance of Integrated Hydronic Heating Systems.

    BUTCHER,T.A.

    2007-12-20

    A variety of system configurations are used in North America to meet the heating and domestic hot water needs of single-family homes. This includes, for example: warm air furnaces with electric water heaters; boilers with integrated hot water coils; and boilers with 'indirect' hot water storage tanks. Integrated hydronic systems which provide both heat and hot water are more popular only in the Northeast and mid-Atlantic regions. For those making decisions about configurations of these integrated hydronic systems, including control options, little information is available concerning the annual energy cost implications of these decisions. This report presents results of a project to use a direct load emulation approach to measure the performance of hydronic systems, develop performance curves, and to provide decision tools to consumers. This is a laboratory measurement system involving direct energy input and output measurements under different load patterns. These results are then used to develop performance correlations for specific systems that can be used to predict energy use in specific applications. A wide range of system types have been tested under this project including conventional boilers with 'tankless' internal coils for domestic hot water production, boilers with indirect external storage tanks, tank type water heaters which may also be used for space heating, condensing oil- and gas-fired systems, and systems with custom control features. It is shown that low load and idle energy losses can have a very large impact on the total annual energy use and that the potential energy savings associated with replacing old equipment with newer, high efficiency equipment with low losses at idle or low load can be in the 25% range. These savings are larger than simple combustion efficiency measurements would indicate.

  13. Energy Savings for Solar Heating Systems

    Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

    2006-01-01

    showed a good degree of similarity. With the boiler model, various simulations of solar domestic hot water heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal...... system. For some conditions the fuel reduction can be up to the double of the solar gain due to a strong increase of the system efficiency. As the monitored boilers were not older than 3 years, it can be assumed that the saving potential with older boilers could be even higher than calculated in this...

  14. Preliminary design activities for solar heating and cooling systems

    1978-01-01

    Information on the development of solar heating and cooling systems is presented. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design activities.

  15. Solar system for domestic hot water and space heating

    Weiss, W. [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

    1997-12-31

    The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

  16. Theory of specific heat in glass-forming systems.

    Hentschel, H G E; Ilyin, Valery; Procaccia, Itamar; Schupper, Nurith

    2008-12-01

    Experimental measurements of the specific heat in glass-forming systems are obtained from the linear response to either slow cooling (or heating) or to oscillatory perturbations with a given frequency about a constant temperature. The latter method gives rise to a complex specific heat with the constraint that the zero frequency limit of the real part should be identified with thermodynamic measurements. Such measurements reveal anomalies in the temperature dependence of the specific heat, including the so called "specific heat peak" in the vicinity of the glass transition. The aim of this paper is to provide theoretical explanations of these anomalies in general and a quantitative theory in the case of a simple model of glass formation. We first present interesting simulation results for the specific heat in a classical model of a binary mixture glass former. We show that in addition to the formerly observed specific heat peak there is a second peak at lower temperatures which was not observable in earlier simulations. Second, we present a general relation between the specific heat, a caloric quantity, and the bulk modulus of the material, a mechanical quantity, and thus offer a smooth connection between the liquid and amorphous solid states. The central result of this paper is a connection between the micromelting of clusters in the system and the appearance of specific heat peaks; we explain the appearance of two peaks by the micromelting of two types of clusters. We relate the two peaks to changes in the bulk and shear moduli. We propose that the phenomenon of glass formation is accompanied by a fast change in the bulk and the shear moduli, but these fast changes occur in different ranges of the temperature. Last, we demonstrate how to construct a theory of the frequency dependent complex specific heat, expected from heterogeneous clustering in the liquid state of glass formers. A specific example is provided in the context of our model for the dynamics of

  17. Analysis of a combined system of an earth-heat-exchanger and a heat pump

    Herz, J.; Doll, A. [Umwelt-Campus Birkenfeld (Germany). Automation and Energy System Technology; Brinkmann, K.

    2004-07-01

    This paper presents an analysis of the system technology of an earth-heatexchanger combined to a heat pump, which was (ca. 1995 - 2002) realised at the building of the Umwelt-Campus in Birkenfeld, which belongs to the University of Applied Sciences Trier in Germany. The heat pump works for a recovery of the stored heat in a massive absorber at the air-outlet, in order to minimise energy losses in the atmosphere. Examinations and comparisons to others up to now realised earth-heat-exchanger projects in Germany, done by Joern Herz for reaching his diploma degree, show, that the special configuration at the Umwelt-Campus Birkenfeld seems to be the first of that kind. This presentation gives an overview of the system technology and working principle. Measurements and mathematical modelling were done, in order to evaluate the efficiency of this combined system and to identify to advantages and disadvantages of this realisation. Additional, practical experiences with stability and working conditions etc., made by Andreas Doll, the responsible technical engineer for the Campus Buildings, are integrated. (orig.)

  18. Estimation of Power Efficiency of Combined Heat Pumping Stations in Heat Power Supply Systems

    I. I. Matsko

    2014-07-01

    Full Text Available The paper considers realization of heat pumping technologies advantages at heat power generation for heat supply needs on the basis of combining electric drive heat pumping units with water heating boilers as a part of a combined heat pumping station.The possibility to save non-renewable energy resources due to the combined heat pumping stations utilization instead of water heating boiler houses is shown in the paper.The calculation methodology for power efficiency for introduction of combined heat pumping stations has been developed. The seasonal heat needs depending on heating system temperature schedule, a low potential heat source temperature and regional weather parameters are taken into account in the calculations.

  19. Corrosion and Heat Transfer Characteristics of Water Dispersed with Carboxylate Additives and Multi Walled Carbon Nano Tubes

    Moorthy, Chellapilla V. K. N. S. N.; Srinivas, Vadapalli

    2016-02-01

    This paper summarizes a recent work on anti-corrosive properties and enhanced heat transfer properties of carboxylated water based nanofluids. Water mixed with sebacic acid as carboxylate additive found to be resistant to corrosion and suitable for automotive environment. The carboxylated water is dispersed with very low mass concentration of carbon nano tubes at 0.025, 0.05 and 0.1 %. The stability of nanofluids in terms of zeta potential is found to be good with carboxylated water compared to normal water. The heat transfer performance of nanofluids is carried out on an air cooled heat exchanger similar to an automotive radiator with incoming air velocities across radiator at 5, 10 and 15 m/s. The flow Reynolds number of water is in the range of 2500-6000 indicating developing flow regime. The corrosion resistance of nanofluids is found to be good indicating its suitability to automotive environment. There is a slight increase in viscosity and marginal decrease in the specific heat of nanofluids with addition of carboxylate as well as CNTs. Significant improvement is observed in the thermal conductivity of nanofluids dispersed with CNTs. During heat transfer experimentation, the inside heat transfer coefficient and overall heat transfer coefficient has also improved markedly. It is also found that the velocity of air and flow rate of coolant plays an important role in enhancement of the heat transfer coefficient and overall heat transfer coefficient.

  20. Multilevel Flow Modeling of Domestic Heating Systems

    Hu, Junjie; Lind, Morten; You, Shi;

    2012-01-01

    Multilevel Flow Modeling (MFM) is a well recognized methodology for functional modeling of complex systems which primarily focuses on the representation of their goals and functions. It has been successfully used in industrial process, e.g. nuclear power plant, chemical plants etc. to facilitate ...... the MFM models. The ‘role’ concept is used to associate the relation between physical structures and functions in all MFM models. This study contributes to MFM library expansion and provides a significant test of the expressivity of MFM....... the operation on fault analysis and control. A significant improvement of the MFM methodology has been recently proposed, where the “role” concept was introduced to enable the representation of structural entities and the conveyance of important information for building up knowledge bases, with the purpose...... of complementing this reasoning methodology. Domestic heating systems, as the main resource to meet the thermal requirements of end-users, have different implementations in Europe in order to achieve various degrees of controllability and heating efficiencies. As all the heating systems serve the same basic needs...

  1. Performance Analysis of a Hybrid District Heating System

    Mikulandric, Robert; Krajačić, Goran; Duic, Neven;

    2015-01-01

    Hybridisation of district heating systems can contribute to more efficient heat generation through cogeneration power plants or through the share increase of renewable energy sources in total energy consumption while reducing negative aspects of particular energy source utilisation. In this work...... systems could contribute to heat production costs decrease in district heating systems up to 30% in comparison with highly efficient heat production technologies based on conventional fuels....

  2. The capric and lauric acid mixture with chemical additives as latent heat storage materials for cooling application

    Roxas-Dimaano, M.N. [University of Santo Tomas, Manila (Philippines). Research Center for the Natural Sciences; Watanabe, T. [Tokyo Institute of Technology (Japan). Research Laboratory for Nuclear Reactors

    2002-09-01

    The mixture of capric acid and lauric acid (C-L acid), with the respective mole composition of 65% and 35%, is a potential phase change material (PCM). Its melting point of 18.0{sup o}C, however, is considered high for cooling application of thermal energy storage. The thermophysical and heat transfer characteristics of the C-L acid with some organic additives are investigated. Compatibility of C-L acid combinations with additives in different proportions and their melting characteristics are analyzed using the differential scanning calorimeter (DSC). Among the chemical additives, methyl salicylate, eugenol, and cineole presented the relevant melting characteristics. The individual heat transfer behavior and thermal storage performance of 0.1 mole fraction of these additives in the C-L acid mixture are evaluated. The radial and axial temperature distribution during charging and discharging at different concentrations of selected PCM combinations are experimentally determined employing a vertical cylindrical shell and tube heat exchanger. The methyl salicylate in the C-L acid provided the most effective additive in the C-L acid. It demonstrated the least melting band width aimed at lowering the melting point of the C-L acid with the highest heat of fusion value with relatively comparable rate of heat transfer. Furthermore, the thermal performance based on the total amount of transferred energy and their rates, established the PCM's latent heat storage capability. (author)

  3. Thermal Protection System (Heat Shield) Development - Advanced Development Project

    Kowal, T. John

    2010-01-01

    The Orion Thermal Protection System (TPS) ADP was a 3 1/2 year effort to develop ablative TPS materials for the Orion crew capsule. The ADP was motivated by the lack of available ablative TPS's. The TPS ADP pursued a competitive phased development strategy with succeeding rounds of development, testing and down selections. The Project raised the technology readiness level (TRL) of 8 different TPS materials from 5 different commercial vendors, eventual down selecting to a single material system for the Orion heat shield. In addition to providing a heat shield material and design for Orion on time and on budget, the Project accomplished the following: 1) Re-invigorated TPS industry & re-established a NASA competency to respond to future TPS needs; 2) Identified a potentially catastrophic problem with the planned MSL heat shield, and provided a viable, high TRL alternate heat shield design option; and 3) Transferred mature heat shield material and design options to the commercial space industry, including TPS technology information for the SpaceX Dragon capsule.

  4. OPTIMISATION OF MANTLE TANKS FOR LOW FLOW SOLAR HEATING SYSTEMS

    Shah, Louise Jivan; Furbo, Simon

    1996-01-01

    programme that simulates the thermal behaviour of low flow SDHW systems. The yearly thermal performance of low flow SDHW systems with different designed mantle tanks has been calculated. The influence of the mantle tank design on the thermal performance is investigated by means of the calculations with the...... programme and by means of tests of three SDHW systems with different designed mantle tanks. Based on the investigations design rules for mantle tanks are proposed. The model, describing the heat transfer coefficients in the mantle is approximate. In addition, the measurements have revealed that a...

  5. Prototype solar heating and combined heating and cooling systems

    1978-01-01

    Designs were completed, hardware was received, and hardware was shipped to two sites. A change was made in the heat pump working fluid. Problem investigation of shroud coatings for the collector received emphasis.

  6. Ion cyclotron resonance heating system on Aditya

    D Bora; Sunil Kumar; Raj Singh; S V Kulkarni; A Mukherjee; J P Singh; Raguraj Singh; S Dani; A Patel; Sai Kumar; V George; Y S S Srinivas; P Khilar; M Kushwah; P Shah; H M Jadav; Rajnish Kumar; S Gangopadhyay; H Machhar; B Kadia; K Parmar; A Bhardwaj; Suresh Adav; D Rathi; D S Bhattacharya

    2005-02-01

    An ion cyclotron resonance heating (ICRH) system has been designed, fabricated indigenously and commissioned on Tokamak Aditya. The system has been commissioned to operate between 20·0 and 47·0 MHz at a maximum power of 200 kW continuous wave (CW). Duration of 500 ms is sufficient for operation on Aditya, however, the same system feeds the final stage of the 1·5 MW ICRH system being prepared for the steady-state superconducting tokamak (SST-1) for a duration of 1000 s. Radio frequency (RF) power (225 kW) has been generated and successfully tested on a dummy load for 100s at 30·0 MHz. Lower powers have been coupled to Aditya in a breakdown experiment. We describe the system in detail in this work.

  7. Investigations of Intelligent Solar Heating Systems for Single Family House

    Andersen, Elsa; Chen, Ziqian; Fan, Jianhua;

    2014-01-01

    tank in tank heat storage with domestic hot water in the inner tank and space heating water in the outer tank. The total tank volume is 750 liters and the solar collector area is 9 m2. The auxiliary energy supply system is based on electrical heating element(s)/heat pump and is different for all three...... systems.The system will be equipped with an intelligent control system where the control of the electrical heating element(s)/heat pump is based on forecasts of the variable electricity price, the heating demand and the solar energy production.By means of numerical models of the systems made in Trnsys......, the control strategy of intelligent solar heating systems is investigated and the yearly auxiliary energy use of the systems and the electricity price for supplying the consumers with domestic hot water and space heating are calculated....

  8. Web Based Information System for Heat Supply Monitoring

    Stoyanov, Borislav; Strahilov, Strahil

    2016-01-01

    The paper presents web based information system for heat supply monitoring. The proposed model  and information system for gathering data from heating station heat-flow meters and regulators is software realized. The novel system with proved functionality can be commercialized at the cost of minimal investments, finding wildly use on Bulgarian market as cheap and quality alternative of the western systems.

  9. Solution to problems of bacterial impurity of heating systems

    Sharapov, V. I.; Zamaleev, M. M.

    2015-09-01

    The article describes the problems of the operation of open and closed district heating systems related to the bacteriological contamination of heating-system water. It is noted that district heating systems are basically safe in sanitary epidemiological terms. Data on the dangers of sulfide contamination of heating systems are given. It is shown that the main causes of the development of sulfate-reducing and iron bacteria in heating systems are a significant biological contamination of source water to fuel heating systems, which is determined by water oxidizability, and a low velocity of the motion of heating-system water in the heating system elements. A case of sulfide contamination of a part of the outdoor heat-supply system of the city of Ulyanovsk is considered in detail. Measures for cleaning pipelines and heating system equipment from the waste products of sulfate-reducing bacteria and iron bacteria and for improving the quality of heating-system water by organizing the hydraulic and water-chemistry condition that makes it possible to avoid the bacteriological contamination of heating systems are proposed. The positive effect of sodium silicate on the prevention of sulfide contamination of heating systems is shown.

  10. A survey of district heating systems in the heating regions of northern China

    To investigate the status quo of heating supply and the impact of energy saving policies in northern China, a survey was conducted on the DHSs (district heating systems) in 15 Chinese cities. The average heating energy consumption was 19.2% lower than in 2008 due to the corresponding policies formulated and promoted by the authorities. Additionally, parameters of DHSs in cold and severe cold zones were collected, which include the energy consumption, operating efficiency, monitoring and control level, and gas emissions. These essential data can serve as a reference for energy efficiency retrofits and further analysis of comprehensive energy consumption of the DHSs in northern China. Finally, suggestions for improving existing policies during “the Twelfth Five-Year Plan” period are put forward to further improve the energy efficiency of DHSs. - Highlights: • To find out the status quo of DHSs (district heating systems) in northern China, a survey was conducted. • Through analyzing the results of survey, main parameters of DHS can be concluded. • By analyzing the existing problems of DHS, the way of retrofit is proposed. • Suggestions are presented to improve relevant policies of DHS in northern China

  11. Auxiliary Heating Systems for the Ignitor Project

    Sassi, M.; Mantovani, S.; Coppi, B.

    2013-10-01

    Auxiliary plasma heating systems directed at extending the range of plasma regimes that can be accessed by Ohmic heating only are important components of the Ignitor machine. In order to affect the entire plasma column an appropriate ICRH systemhas been designed and components of it have been tested. The adoption of a 280 GHz system affecting, by ECRH, the outer edge of the plasma column has been proposed in order to influence temperature and density profiles in this important region. The ICRH system will operate over the range 80-120 MHz, consistent with magnetic fields in the range 9-13 T. The maximum delivered power goes from 8 MW (at 80 MHz) to 6 MW (at 120 MHz) distributed over 4 ports. A full size prototype of the VTL between the port flange and the antenna straps, with the external support and precise guiding system has been constructed. The innovative quick latching system located at the end of the coaxial cable has been successfully tested, providing perfect interference with the spring Be-Cu electrical contacts. Vacuum levels of 10-6, compatible with the limit of material degassing, and electrical tests up to 12 kV without discharges have been obtained. Special attention was given to the finishing of the inox surfaces, and to the TIG welds. U.S. DOE sponsored.

  12. Efficiency of heat pump ventilation and water heating system in an indoor swimming pool

    Безродний, Михайло Костянтинович; Кутра, Дмитро Сергійович; Морощук, Олександр Олександрович

    2014-01-01

    The thermodynamic efficiency of the heat pump ventilation and water heating system of indoor swimming pool with partial exhaust air recirculation and heat pump bypass is analyzed in the paper. The purpose of the work is to determine the system efficiency depending on the change of fresh supply air temperature, ventilation system intensity and heat pump bypassing factor. As a result of implementing the developed mathematical model using the method of successive approximations, dependences of t...

  13. Total Energy Recovery System for Agribusiness. [Geothermally heated]. Final Report

    Fogleman, S.F.; Fisher, L.A.; Black, A.R.; Singh, D.P.

    1977-05-01

    An engineering and economic study was made to determine a practical balance of selected agribusiness subsystems resulting in realistic estimated produce yields for a geothermally heated system known as the Total Energy Recovery System for Agribusiness. The subsystem cycles for an average application at an unspecified hydrothermal resources site in the western United States utilize waste and by-products from their companion cycles insofar as practicable. Based on conservative estimates of current controlled environment yields, produce wholesale market prices, production costs, and capital investment required, it appears that the family-operation-sized TERSA module presents the potential for marginal recovery of all capital investment costs. In addition to family- or small-cooperative-farming groups, TERSA has potential users in food-oriented corporations and large-cooperative-agribusiness operations. The following topics are considered in detail: greenhouse tomatoes and cucumbers; fish farming; mushroom culture; biogas generation; integration methodology; hydrothermal fluids and heat exchanger selection; and the system. 133 references. (MHR)

  14. Feasibility study of helically coiled tube condensation heat exchanger for a passive auxiliary feedwater system

    The Passive Auxiliary Feedwater System (PAFS) with nearly-horizontal heat exchangers is one of passive safety features of APR+ (Advanced Power Reactor Plus) which provides the auxiliary feedwater by means of natural circulation with condensation. It is feasible to increase the heat transfer capacity of the PAFS by employing a helically coiled heat exchanger due to additional secondary flow effect by centrifugal force. In addition, a compact and flexible design can be achieved in a fixed volume by using the helically coiled heat exchanger, which is one of the most important merits of implementing this heat exchanger. In this paper, the helically coiled heat exchanger has been employed for the PAFS instead of nearly-horizontal heat exchanger. In order to evaluate the heat transfer performance of the helically coiled heat exchanger, an in-tube condensation heat transfer correlation by Wongwises has been introduced into the system analysis code, MARS-KS. A comparative numerical study was conducted for both heat exchangers. The result shows that helically coiled heat exchanger has 20% higher heat transfer efficiency than existing nearly-horizontal heat exchanger. (author)

  15. Small-Scale Pellet Heating Systems from Consumer Perspective

    A questionnaire survey of 1,500 detached house owners was carried out in the autumn of 2004 to find out the factors influencing the adoption and diffusion of pellet heating systems in the Swedish residential sector. The results revealed that most of the respondents had no plans to install new heating systems as they were satisfied with their existing ones. Economic aspects and functional reliability were the most important factors in the respondents' choice of heating system while environmental factors were of less importance. Therefore, internalizing external costs, such as environmental costs, might be effective in influencing house owners to adopt environmentally benign heating systems. Installers were the most important source of information on heating systems. Hence, it is important that they could inform the consumers comprehensively and accurately about different heating systems. Respondents perceived the relative advantage of pellet boilers over oil or electricity-based heating systems, but bedrock heat pump system was ranked higher than pellet heating system in every aspect except for investment cost. Pellet heating system has advantage over district heating system with respect to investment cost and annual cost of heating. District heating system was considered as most functionally reliable and automatic

  16. Microcontroller based automatic liquid poison addition control system

    Microcontrollers are finding increasing applications in instrumentation where complex digital circuits can be substituted by a compact and simple circuit, thus enhancing the reliability. In addition to this, intelligence and flexibility can be incorporated. For applications not requiring large amount of read/write memory (RAM), microcontrollers are ideally suited since they contain programmable memory (Eprom), parallel input/output lines, data memory, programmable timers and serial interface ports in one chip. This paper describes the design of automatic liquid poison addition control system (ALPAS) using intel's 8 bit microcontroller 8751, which is used to generate complex timing control sequence signals for liquid poison addition to the moderator in a nuclear reactor. ALPAS monitors digital inputs coming from protection system and regulating system of a nuclear reactor and provides control signals for liquid poison addition for long term safe shutdown of the reactor after reactor trip and helps the regulating system to reduce the power of the reactor during operation. Special hardware and software features have been incorporated to improve performance and fault detection. (author)

  17. Test Procedure - pumping system for caustic addition project

    This test procedure provides the requirements for sub-system testing and integrated operational testing of the submersible mixer pump and caustic addition equipment by WHC and Kaiser personnel at the Rotating Equipment Shop run-in pit (Bldg. 272E)

  18. Submersible pumping system with heat transfer mechanism

    Hunt, Daniel Francis Alan; Prenger, F. Coyne; Hill, Dallas D; Jankowski, Todd Andrew

    2014-04-15

    A submersible pumping system for downhole use in extracting fluids containing hydrocarbons from a well. In one embodiment, the pumping system comprises a rotary induction motor, a motor casing, one or more pump stages, and a cooling system. The rotary induction motor rotates a shaft about a longitudinal axis of rotation. The motor casing houses the rotary induction motor such that the rotary induction motor is held in fluid isolation from the fluid being extracted. The pump stages are attached to the shaft outside of the motor casing, and are configured to impart fluid being extracted from the well with an increased pressure. The cooling system is disposed at least partially within the motor casing, and transfers heat generated by operation of the rotary induction motor out of the motor casing.

  19. AUTOMATIC CONTROL SYSTEM OF HEAT PUMP STATION GAS COOLER AT THE WIDE RANGE OF HEAT LOAD

    Juravleov A.A.

    2008-08-01

    Full Text Available There is examined the structure the of control system of gas cooler of heat pump station, which uses the carbon dioxide as the working fluid in the transctitical thermodynamical cycle. It is analiyed the structure of the complex: heat pump station – district heating system.

  20. AUTOMATIC CONTROL SYSTEM OF HEAT PUMP STATION GAS COOLER AT THE WIDE RANGE OF HEAT LOAD

    Juravleov A.A.; Sit M.L.; Sit B.M.; Poponova O.; Zubatii A.

    2008-01-01

    There is examined the structure the of control system of gas cooler of heat pump station, which uses the carbon dioxide as the working fluid in the transctitical thermodynamical cycle. It is analiyed the structure of the complex: heat pump station – district heating system.

  1. Prototype testing of heat pipes for spacecraft heat control systems

    Vasil' ev, L.L.; Gil, V.V.; Zharikov, N.A.; Zelenin, V.E.; Syvorotka, O.M.; Uvarov, E.I.

    1980-05-01

    Prototype testing of heat pipes for spacecraft heat control was done on board the Interkosmos-15 satellite launched on 19 June 1976. The purpose was to gather data for optimizing the design, namely the capillary structure and the selection of heat transfer agent, as well as to verify the soundness of manufacturing technologies and test procedures. Three heat pipes were tested, each 412 mm long with a 14 mm outside diameter. All had been made of an aluminum alloy. In two pipes the capillary structure consisted of 0.6 x 0.5 mm/sup 2/ rectangular channels running axially along the inside wall, in the third pipe a 1 mm thick tubular mesh of Kh18N10T steel wire running coaxially inside served as the capillary structure. The heat transfer agent was Freon-11 in one of the first two pipes and synthetic liquid ammonia in the other two pipes. The three pipes were mounted radially around a radiator as the hub, with the test conditions controllable by means of an electric heater coil along the evaporation zone of each pipe, resistance thermometers for the evaporation zone and for the condensation zone of each, and also an external cooling fan. The radial distribution of temperature drops along the pipes was measured and the thermal fluxes were calculated, these data being indicative of the performance under conditions of weightlessness over the 0 to 70/sup 0/C temperature range. The somewhat worse performance of the heat pipe with a tubular capillary mesh inside is attributable to formation of vapor bubbles which impede the mass transfer along such an artery.

  2. District heating systems for small scale development areas

    McDougall, Rory e-mail: rory.mcdougall@online.no; Jensen, Bjoernulf

    2008-09-15

    Building projects are normally developed without considering integrated heating systems, especially where properties are for further sale. Due to focus on energy efficiency and environmental impact it is worth considering district heating systems, which include several energy carriers. The choice of energy carrier is assessed to optimize energy costs, account for environmental impact and obtain reliable heating supply, thus giving an energy flexible system for several buildings as opposed to individual heating systems in each building

  3. 40 CFR 60.4176 - Additional requirements to provide heat input data.

    2010-07-01

    ... input data. 60.4176 Section 60.4176 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... requirements to provide heat input data. The owner or operator of a Hg Budget unit that monitors and reports Hg... monitor and report heat input rate at the unit level using the procedures set forth in part 75 of...

  4. One-dimensional analysis of unsteady flows due to supercritical heat addition in high speed condensing steam

    Unsteadiness in supersonic flow in nozzles can be generated by the release of heat due to spontaneous condensation. The heat released is termed 'supercritical' and may be responsible for turbine blades failure in turbine cascade as it causes a supersonic flow to decelerate. When the Mach number is reduced to unity, the flow can no longer sustain the additional heat and becomes unstable. This paper aims to numerically investigate the unsteadiness caused by supercritical heat addition in one-dimensional condensing flows. The governing equations for mass, momentum and energy, coupled with the equations describing the wetness fraction and droplet growth are integrated and solved iteratively to reveal the final solution. Comparison is made with well-established experimental and numerical solution done by previous researchers that shows similar phenomena.

  5. Heat Saving Strategies in Sustainable Smart Energy Systems

    Henrik Lund

    2014-06-01

    Full Text Available This paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used in future sustainable smart energy systems. Based on a concrete proposal to implement the Danish governmental 2050 fossil-free vision, this paper identifies marginal heat production costs and compares these to marginal heat savings costs for two different levels of district heating. A suitable least-cost heating strategy seems to be to invest in an approximately 50% decrease in net heat demands in new buildings and buildings that are being renovated anyway, while the implementation of heat savings in buildings that are not being renovated hardly pays. Moreover, the analysis points in the direction that a least-cost strategy will be to provide approximately 2/3 of the heat demand from district heating and the rest from individual heat pumps.

  6. Heat losses and thermal performance of commercial combined solar and pellet heating systems

    Fiedler, Frank; Persson, Tomas; Bales, Chris; Nordlander, Svante

    2004-01-01

    Various pellet heating systems are marketed in Sweden, some of them in combination with a solar heating system. Several types of pellet heating units are available and can be used for a combined system. This article compares four typical combined solar and pellet heating systems: System 1 and 2 two with a pellet stove, system 3 with a store integrated pellet burner and system 4 with a pellet boiler. The lower efficiency of pellet heaters compared to oil or gas heaters increases the primary en...

  7. Operation strategy analysis of a geothermal step utilization heating system

    Geothermal energy has been successfully applied in many district heating systems. In order to promote better use of geothermal energy, it is important to analyze the operation strategy of geothermal heating system. This study proposes a comprehensive and systematic operation strategy for a geothermal step utilization heating system (GSUHS). Calculation models of radiator heating system (RHS), radiant floor heating system (RFHS), heat pump (HP), gas boiler (GB), plate heat exchanger (PHE) and pump are first established. Then the operation strategy of the GSUHS is analyzed with the aim to substantially reduce the conventional energy consumption of the whole system. Finally, the energy efficiency and geothermal tail water temperature are analyzed. With the operation strategy in this study, the geothermal energy provides the main heating amount for the system. The heating seasonal performance factor is 15.93. Compared with coal-fired heating, 75.1% of the standard coal equivalent can be saved. The results provide scientific guidance for the application of an operation strategy for a geothermal step utilization heating system. -- Highlights: ► We establish calculation models for the geothermal step utilization heating system. ► We adopt minimal conventional energy consumption to determine the operation strategy. ► The geothermal energy dominates the heating quantity of the whole system. ► The utilization efficiency of the geothermal energy is high. ► The results provide guidance to conduct operation strategy for scientific operation.

  8. Performance analysis on solar-water compound source heat pump for radiant floor heating system

    曲世林; 马飞; 仇安兵

    2009-01-01

    A solar-water compound source heat pump for radiant floor heating (SWHP-RFH) experimental system was introduced and analyzed. The SWHP-RFH system mainly consists of 11.44 m2 vacuum tube solar collector,1 000 L water tank assisted 3 kW electrical heater,a water source heat pump,the radiant floor heating system with cross-linked polyethylene (PE-X) of diameter 20 mm,temperature controller and solar testing system. The SWHP-RFH system was tested from December to February during the heating season in Beijing,China under different operation situations. The test parameters include the outdoor air temperature,solar radiation intensity,indoor air temperature,radiation floor average surface temperature,average surface temperature of the building envelope,the inlet and outlet temperatures of solar collector,the temperature of water tank,the heat medium temperatures of heat pump condenser side and evaporator side,and the power consumption includes the water source heat pump system,the solar source heat pump system,the auxiliary heater and the radiant floor heating systems etc. The experimental results were used to calculate the collector efficiency,heat pump dynamic coefficient of performance (COP),total energy consumption and seasonal heating performance during the heating season. The results indicate that the performance of the compound source heat pump system is better than that of the air source heat pump system. Furthermore,some methods are suggested to improve the thermal performance of each component and the whole SWHP-RFH system.

  9. Heating Transfer Investigation of Heater in Heat Supply System of Field Hospital Operating in Emergency

    I. L. Kachar

    2014-01-01

    Criteria dependences for assessment of heat transfer value under conditions natural convection (a horizontal slot) have been obtained in the paper. The dependences are applicable for heaters in heat supply systems.

  10. Heating Transfer Investigation of Heater in Heat Supply System of Field Hospital Operating in Emergency

    I. L. Kachar

    2014-08-01

    Full Text Available Criteria dependences for assessment of heat transfer value under conditions natural convection (a horizontal slot have been obtained in the paper. The dependences are applicable for heaters in heat supply systems.

  11. Development and testing of heat transport fluids for use in active solar heating and cooling systems

    Parker, J. C.

    1981-01-01

    Work on heat transport fluids for use with active solar heating and cooling systems is described. Program objectives and how they were accomplished including problems encountered during testing are discussed.

  12. On heat balance in coal-fired MHD systems, channel heat transfer and electrode temperature distribution

    This paper presents results from heat transfer studies performed in 7.5 MW/sub t/ and 15 MW/sub t/ direct coal-fired magnetohydrodynamic systems for electrical power generation. Heat transfer from the various components is measured to determine system heat balance and the influence of parameters related to coal combustion on heat transfer. Measured heat flux from electrode walls is compared with a quasi one-dimensional model and extended for off-design operation. The heat flux values are used in a computer model to evaluate temperature distribution in electrode frames and caps and are compared with measurements taken during power runs. 9 refs

  13. Reliability analysis of the combined district heating systems

    Sharapov, V. I.; Orlov, M. E.; Kunin, M. V.

    2015-12-01

    Technologies that improve the reliability and efficiency of the combined district heating systems in urban areas are considered. The calculation method of reliability of the CHP combined district heating systems is proposed. The comparative estimation of the reliability of traditional and combined district heating systems is performed.

  14. Heat-Transfer Fluids for Solar-Energy Systems

    Parker, J. C.

    1982-01-01

    43-page report investigates noncorrosive heat-transport fluids compatible with both metallic and nonmetallic solar collectors and plumbing systems. Report includes tables and figures of X-ray inspections for corrosion and schematics of solar-heat transport systems and heat rejection systems.

  15. Numerical Investigation of Floor Heating Systems in Low Energy Houses

    Weitzmann, Peter; Kragh, Jesper; Jensen, Claus Franceos

    2002-01-01

    to the room air and between the room surfaces. The simulation model has been used to calculate heating demand and room temperature in a typical well insulated Danish single-family house with a heating demand of approximately 6000 kWh per year, for a 130 m² house. Two different types of floor heating...... heating and cooling systems exist. In Denmark over 80 % of all new single-family houses are using the building integrated floor heating systems. Therefore methods to evaluate building integrated heating must be developed. To examine this a simulation model of a room with floor heating has been created...

  16. Residual heat removal system diagnostic advisor

    This paper reports on the Residual Heat Removal System (RHRS) Diagnostic Advisor which is an expert system designed to alert the operators to abnormal conditions that exits in the RHRS and offer advice about the cause of the abnormal conditions. The Advisor uses a combination of rule-based and model-based diagnostic techniques to perform its functions. This diagnostic approach leads to a deeper understanding of the RHRS by the Advisor and consequently makes it more robust to unexpected conditions. The main window of the interactive graphic display is a schematic diagram of the RHRS piping system. When a conclusion about a failed component can be reached, the operator can bring up windows that describe the failure mode of the component and a brief explanation about how the Advisor arrived at its conclusion

  17. Power system for electric heating of pipelines

    Novik, Frode Karstein

    2008-01-01

    Direct electrical heating (DEH) of pipelines is a flow assurance method that has proven to be a good and reliable solution for preventing the formation of hydrates and wax in multiphase flow lines. The technology is installed on several pipelines in the North Sea and has become StatoilHydros preferred method for flow assurance. Tyrihans is the newest installation with 10 MW DEH for a 43 km pipline. However, the pipeline represents a considerable single-phase load which makes the power system ...

  18. Calculating the cost of heat supply systems

    The question of whether or not a cogeneration unit will be economically successful when realized is decided early on in the planning stage. Indispensable prerequisites are the exact knowledge of the cold, heat, or electricity demand of consumers on an hourly basis and a detailed analysis of the hydraulic and electrical connection possibilites for such systems. Aspects now increasingly considered when deciding on investments are not only which is the most economical form of energy generation but also comparisons regarding emissions of CO2, NOx, and ozone-depleting substances (refrigerants). (orig.)

  19. Modelling the Size of Seasonal Thermal Storage in the Solar District Heating System

    Giedrė Streckienė

    2012-12-01

    Full Text Available The integration of a thermal storage system into the solar heating system enables to increase the use of solar thermal energy in buildings and allows avoiding the mismatch between consumers’ demand and heat production in time. The paper presents modelling a seasonal thermal storage tank various sizes of which have been analyzed in the district solar heating system that could cover a part of heat demand for the district of individual houses in Vilnius. A biomass boiler house, as an additional heat source, should allow covering the remaining heat demand. energyPRO software is used for system modelling. The paper evaluates heat demand, climate conditions and technical characteristics.Article in Lithuanian

  20. Condensing Heat Exchanger Concept Developed for Space Systems

    Hasan, Mohammad M.; Nayagam, Vedha

    2005-01-01

    The current system for moisture removal and humidity control for the space shuttles and the International Space Station uses a two-stage process. Water first condenses onto fins and is pulled through "slurper bars." These bars take in a two-phase mixture of air and water that is then separated by the rotary separator. A more efficient design would remove the water directly from the air without the need of an additional water separator downstream. For the Condensing Heat Exchanger for Space Systems (CHESS) project, researchers at the NASA Glenn Research Center in collaboration with NASA Johnson Space Center are designing a condensing heat exchanger that utilizes capillary forces to collect and remove water and that can operate in varying gravitational conditions including microgravity, lunar gravity, and Martian gravity.

  1. An Integrated Control System for Heating and Indoor Climate Applications

    Tahersima, Fatemeh

    2012-01-01

    Low temperature hydronic heating and cooling systems connected to renewable energy sources have gained more attention in the recent decades. This is due to the growing public awareness of the adverse environmental impacts of energy generation using fossil fuel. Radiant hydronic sub-floor heating...... pipes and radiator panels are two examples of such systems that have reputation of improving the quality of indoor thermal comfort compared to forced-air heating or cooling units. Specifically, a radiant water-based sub-floor heating system is usually combined with low temperature heat sources, among...... which geothermal heat pump, solar driven heat pumps and the other types are categorized as renewable or renewable energy sources. In the present study, we investigated modeling and control of hydronic heat emitters integrated with a ground-source heat pump. Optimization of the system performance...

  2. Heating performance of a ground source heat pump system installed in a school building

    Jaedo; SONG; Kwangho; LEE; Youngman; JEONG; Seongir; CHEONG; Jaekeun; LEE; Yujin; HWANG; Yeongho; LEE; Donghyuk; LEE

    2010-01-01

    The heating performance of a water-to-refrigerant type ground source heat pump system is represented in this paper under the actual working conditions of the GSHP(ground source heat pump) system during the winter season of 2008.Ten heat pump equipments with the capacity of 10 HP each and a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth were constructed.We investigated a variety of working conditions,including the outdoor temperature,the ground temperature,and the water temperature of inlet and outlet of the ground heat exchanger in order to examine the heating performance of the GSHP system.Subsequently,the heating capacity and the input power were investigated to determine the heating performance of the GSHP system.The average heating coefficient of performance(COP) of the heat pump was noted to be 5.1 at partial load of 47%,while the overall system COP was found to be 4.2.Also,performance of the GSHP system was compared with that of air source heat pump.

  3. Limiting biomass consumption for heating in 100% renewable energy systems

    Mathiesen, Brian Vad; Lund, Henrik; Connolly, David

    2012-01-01

    for other sectors, but while still enabling a 100% renewable energy system. The analyses of heating technologies shows that district heating (DH) systems are important in limiting the dependence on biomass and create cost effective solutions. DH systems are especially important in renewable energy...... such as large-scale solar thermal, large heat pumps, geothermal heat, industrial surplus heat, and waste incineration. Where the energy density in the building stock is not high enough for DH to be economical, geothermal heat pumps can be recommended for individual heating systems, even though biomass......The utilisation of biomass poses large challenges in renewable energy systems while buildings account for a substantial part of the energy supply even in 100% renewable energy systems. In this paper the focus is on how the heating sector can reduce its consumption of biomass, thus leaving biomass...

  4. Heat pump system utilizing produced water in oil fields

    As the alternative to the heating furnace for crude oil heating, a heat pump system utilizing produced water, a main byproduct, in oil fields was proposed and the thermodynamic model of the system was established. A particular compression process with inner evaporative spray water cooling was applied in the screw compressor and an analysis method for the variable-mass compression process was introduced. The simulation results showed that the efficiency of the screw compressor, the temperature of produced water and the temperature difference in flash process are key parameters affecting the system performance. The energy cost of the heat pump system was compared to that of the heating furnace, revealing that the heat pump system with EER, 4.67, would save over 20% energy cost as compared with the heating furnace. Thus, the heat pump system was energy saving, money saving and environmentally benign

  5. Texas experimental tokamak electron cyclotron resonant heating system

    Electron cyclotron resonant heating of the plasma in the Texas Experimental Tokamak (TEXT) has been achieved with a single gyrotron system, and is presently being expanded to a three gyrotron system. Each gyrotron can provide up to 200 kilowatts of rf power into the plasma. Future expansion includes a fourth gyrotron capable of delivering an additional 500 kilowatts of rf power into the plasma. A description of the overall system architecture is given in this paper. Also discussed is the overall grounding scheme and the high-voltage power distribution system. The utilization of fiber-optic links in the control system to reduce noise problems associated with high-voltage systems, provide high-voltage isolation, and eliminate ground loops is also discussed. 3 refs., 5 figs

  6. Combined heat transfer in a system for solar heating and radiative cooling

    2009-01-01

    The goal of this work is to study a system, which covers both the demands for heating and cooling of a building. The system is designed to be one large central installation for storage and distribution. Such systems obviously reveal a large cost-competitiveness. The design foresees solar collectors for heating and radiative cooling panels, which could be combined with an external electric fan, for cooling the water in the storage. In the present system design, the heat storage tank is divided...

  7. Electron Cyclotron Resonance Heating (ECRH) Control System

    The ECRH Control System was installed on the Tandem Mirror Experiment-Upgrade (TMX-U) in 1980. The system provides approximately 1 MW of 28 GHz microwave power to the TMX-U plasma. The subsystems of ECRH that must be controlled include high-voltage charging supplies, series pass tubes, and magnet supplies. In addition to the devices that must be controlled, many interlocks must be continuously monitored. The previous control system used relay logic and analog controls to operate the system. This approach has many drawbacks such as lack of system flexibility and maintainability. In order to address these problems, it was decided to go with a CAMAC and Modicon based system that uses a Hewlett-Packard 9836C personal computer to replace the previous analog controls. This paper describes the advantages, disadvantages, and the day-to-day operations of this new computer-based control and data acquisition system

  8. System and method for high power diode based additive manufacturing

    El-Dasher, Bassem S.; Bayramian, Andrew; Demuth, James A.; Farmer, Joseph C.; Torres, Sharon G.

    2016-04-12

    A system is disclosed for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system may make use of a diode array for generating an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.

  9. A Numerical Study on System Performance of Groundwater Heat Pumps

    Jin Sang Kim; Yujin Nam

    2015-01-01

    Groundwater heat pumps have energy saving potential where the groundwater resources are sufficient. System Coefficients of Performance (COPs) are measurements of performance of groundwater heat pump systems. In this study, the head and power of submersible pumps, heat pump units, piping, and heat exchangers are expressed as polynomial equations, and these equations are solved numerically to determine the system performance. Regression analysis is used to find the coefficients of the polynomia...

  10. Prototype solar heating and cooling systems, including potable hot water

    Bloomquist, D.; Oonk, R. L.

    1977-01-01

    Progress made in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water is reported. The system consists of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition. A comparison of the proposed Solaron Heat Pump and Solar Desiccant Heating and Cooling Systems, installation drawings, data on the Akron House at Akron, Ohio, and other program activities are included.

  11. Heat Saving Strategies in Sustainable Smart Energy Systems

    Lund, Henrik; Thellufsen, Jakob Zinck; Aggerholm, Søren;

    One of the important issues related to the implementation of future sustainable smart energy systems based on renewable energy sources is the heating of buildings. Especially, when it comes to long‐term investment in savings and heating infrastructures it is essential to identify long‐term least...... a least‐cost strategy will be to provide approximately 2/3 of the heat demand from district heating and the rest from individual heat pumps. Keywords: Energy Efficiency, Renewable energy, Heating strategy, Heat savings, District heating, Smart energy......‐cost strategies. With Denmark as a case, this paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used. Based on a concrete proposal to implement the Danish governmental long...

  12. Heat Saving Strategies in Sustainable Smart Energy Systems

    Lund, Henrik; Thellufsen, Jakob Zinck; Aggerholm, Søren;

    2014-01-01

    This paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used in future sustainable smart energy systems. Based on a concrete proposal to implement the Danish...... governmental 2050 fossil-free vision, this paper identifies marginal heat production costs and compares these to marginal heat savings costs for two different levels of district heating. A suitable least-cost heating strategy seems to be to invest in an approximately 50% decrease in net heat demands in new...... buildings and buildings that are being renovated anyway, while the implementation of heat savings in buildings that are not being renovated hardly pays. Moreover, the analysis points in the direction that a least-cost strategy will be to provide approximately 2/3 of the heat demand from district heating and...

  13. Compact interior heat exchangers for CO{sub 2} mobile heat pumping systems

    Hafner, Armin

    2003-07-01

    The natural refrigerant carbon dioxide (CO{sub 2}) offers new possibilities for design of flexible, efficient and environmentally safe mobile heat pumping systems. As high-efficient car engines with less waste heat are developed, extra heating of the passenger compartment is needed in the cold season. A reversible transcritical CO{sub 2} system with gliding temperature heat rejection can give high air delivery temperature which results in rapid heating of the passenger compartment and rapid defogging or defrosting of windows. When operated in cooling mode, the efficiency of transcritical CO{sub 2} systems is higher compared to common (HFC) air conditioning systems, at most dominant operating conditions. Several issues were identified for the design of compact interior heat exchangers for automotive reversible CO{sub 2} heat pumping systems. Among theses issues are: (1) Refrigerant flow distribution, (2) Heat exchanger fluid flow circuiting, (3) Air temperature uniformity downstream of the heat exchanger, (4) Minimization of temperature approach, (5) Windshield flash fogging due to retained water inside the heat exchanger, (6) Internal beat conduction in heating mode operation, and (7) Refrigerant side pressure drop In order to provide a basis for understanding these issues, the author developed a calculation model and set up a test facility and investigated different prototype heat exchangers experimentally.

  14. A Numerical Study on System Performance of Groundwater Heat Pumps

    Jin Sang Kim

    2015-12-01

    Full Text Available Groundwater heat pumps have energy saving potential where the groundwater resources are sufficient. System Coefficients of Performance (COPs are measurements of performance of groundwater heat pump systems. In this study, the head and power of submersible pumps, heat pump units, piping, and heat exchangers are expressed as polynomial equations, and these equations are solved numerically to determine the system performance. Regression analysis is used to find the coefficients of the polynomial equations from a catalog of performance data. The cooling and heating capacities of water-to-water heat pumps are determined using Energy Plus. Results show that system performance drops as the water level drops, and the lowest flow rates generally achieve the highest system performance. The system COPs are used to compare the system performance of various system configurations. The groundwater pumping level and temperature provide the greatest effects on the system performance of groundwater heat pumps along with the submersible pumps and heat exchangers. The effects of groundwater pumping levels, groundwater temperatures, and the heat transfer coefficient in heat exchanger on the system performance are given and compared. This analysis needs to be included in the design process of groundwater heat pump systems, possibly with analysis tools that include a wide range of performance data.

  15. Design and demonstration analysis of secondary side passive residual heat removal system

    A new secondary side passive residual heat removal system (PRHRS) was designed, which used high-level tanks as the heat sink and remove residual heat by natural circulation at secondary side of steam generator. Based on the reactor coolant system of Daya Bay NPP, the characteristics of PRHRS during station blackout (SBO) were analyzed by RELAP5/MOD 3.2 code. It is shown that core residual heat is able to be removed effectively by natural circulation at secondary side and the capacity of system can be assured by the PRHRS which is rationally designed. In addition, factors, such as the location of passive heat exchangers, the startup time of PRHRS, and the surface of heat exchangers affecting the capability of residual heat removal were analyzed. (authors)

  16. Mathematical model for calculation of the heat-hydraulic modes of heating points of heat-supplying systems

    Shalaginova, Z. I.

    2016-03-01

    The mathematical model and calculation method of the thermal-hydraulic modes of heat points, based on the theory of hydraulic circuits, being developed at the Melentiev Energy Systems Institute are presented. The redundant circuit of the heat point was developed, in which all possible connecting circuits (CC) of the heat engineering equipment and the places of possible installation of control valve were inserted. It allows simulating the operating modes both at central heat points (CHP) and individual heat points (IHP). The configuration of the desired circuit is carried out automatically by removing the unnecessary links. The following circuits connecting the heating systems (HS) are considered: the dependent circuit (direct and through mixing elevator) and independent one (through the heater). The following connecting circuits of the load of hot water supply (HWS) were considered: open CC (direct water pumping from pipelines of heat networks) and a closed CC with connecting the HWS heaters on single-level (serial and parallel) and two-level (sequential and combined) circuits. The following connecting circuits of the ventilation systems (VS) were also considered: dependent circuit and independent one through a common heat exchanger with HS load. In the heat points, water temperature regulators for the hot water supply and ventilation and flow regulators for the heating system, as well as to the inlet as a whole, are possible. According to the accepted decomposition, the model of the heat point is an integral part of the overall heat-hydraulic model of the heat-supplying system having intermediate control stages (CHP and IHP), which allows to consider the operating modes of the heat networks of different levels connected with each other through CHP as well as connected through IHP of consumers with various connecting circuits of local systems of heat consumption: heating, ventilation and hot water supply. The model is implemented in the Angara data

  17. The heating study 2003. The basis for construction and use of heating energy in the Norwegian energy system

    The heating study is a result of cooperation between Enova and central parties in the Norwegian heating market. The Enova participation shall stimulate to reach the aim of 4 TWh new heating energy before 2010 at the same time as the contractor focuses on cost efficient projects with lasting effects and as large spin-off effects as possible. The study shows that it should be possible to reach the goals with emphasis on a selected portfolio. The study comprises heating energy based on biomass, waste, waste heat and heat pumps. The availability of renewable energy sources is analyzed and compared to the potential in the end user market. Important obstacles for reaching the Enova goals are discussed. The total net energy consumption in Norway in 2001 was 225 TWh, of this approx. 50 TWh was used for heating of residences. Considering the historical development rate, economical conditions and resource accesses it is estimated that the renewable heating supply towards 2010 would be: 1) New process heating supplies to the Norwegian industry from waste based energy recirculation and biomass, approx. 2 TWh. 2) New renewable district heating (waste, energy recirculation and heat pumps), approx. 2 TWh. 3) New heating supplies from heat centers and central heating installations, approx. 1.5 TWh. As heating energy based on energy recirculation from waste is the cheapest alternative for large scale district heating systems possible limitations in the supplies this will influence the national activity level for district heating. Official support of refuse plants should focus on risk reducing projects. For both bio and heat pumps there are needs for both profits increasing and risk reducing measures. The report concludes that it should be possible to reach the goal of 4 TWh renewable heating energy by 2010 but this requires a substantial increase in the construction rate. The success is based on a focus on quality assurance and involvement in the entire activity chain. It is

  18. Environmental issues and competitiveness of district heating systems

    The advantages of district heating systems are evaluated in competition to individual heating for the Swiss markets. The preservation of the environmental quality on the national (clean air concept) and global scale (Toronto recommendation) is formulated as constraint of the energy system. The implications of these constraints for the economic competition of district heating is evaluated. The study estimates the evolution of energy demand in the heating markets and shortly describes the technical possibilities in satisfying demand by a set of conventional heating systems, systems using renewable energy sources, energy conservation measures and district heating systems based on conventional or nuclear energy sources. The main conclusion is that small capacity nuclear district heating systems, if acceptable, could enhance the flexibility of the Swiss energy system in respect to CO2 control. (author) 3 figs., 4 tabs., 9 refs

  19. Investigation of a heat storage for a solar heating system for combined space heating and domestic hot water supply for homeowner´s association "Bakken"

    Vejen, Niels Kristian

    1998-01-01

    A heat storage for a solar heating system for combined space heating and domestic hot water supply was tested in a laboratory test facility.The heat storage consist of a mantle tank with water for the heating system and of a hot water tank, which by means of thermosyphoning is heated by the water...... in the heating system. The heat storage was tested in a heat storage test facility. The most important characteristics of the heat storage were determined by means of the tests and recommendations for the design of the heat storage were given....

  20. Influencing Swedish homeowners to adopt district heating system

    Improved energy efficiency and greenhouse gas mitigation could be achieved by replacing resistance heaters with district heating system. In 2005, only about 8% of the Swedish detached houses had district heating system. The expansion of such systems largely depends on homeowners' adoption decisions. And, to motivate homeowners to adopt district heating, it is essential to understand their decision-making process. In this context, in June 2005 we carried out a questionnaire survey of about 700 homeowners who lived in the city of Ostersund in houses with resistance heaters (baseline survey). About 84% of the respondents did not intend to install a new heating system. Since then these homeowners were influenced by (a) an investment subsidy by the Swedish government to replace resistance heaters with district heating, a brine/water-based heat pump, or a biomass-based heating system and (b) a marketing campaign by the municipality-owned district heating company. This paper analyses how these two measures influenced about 78% of the homeowners to adopt the district heating system. For this purpose we carried out a follow-up survey of the same homeowners in December 2006 (resurvey). Results showed that the investment subsidy and the marketing campaign created a need among the homeowners to adopt a new heating system. The marketing campaign was successful in motivating them to adopt the district heating system. The marketing strategy by the district heating company corresponds to the results obtained in the baseline survey

  1. Solar heating and cooling systems design and development. [prototype development

    1977-01-01

    The development of twelve prototype solar heating/cooling systems, six heating and six heating and cooling systems, two each for single family, multi-family, and commercial applications, is reported. Schedules and technical discussions, along with illustrations on the progress made from April 1, 1977 through June 30, 1977 are detailed.

  2. 40 CFR 63.1328 - Heat exchange systems provisions.

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Heat exchange systems provisions. 63... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1328 Heat exchange... of this subpart. (h) The compliance date for heat exchange systems subject to the provisions of...

  3. Ultimate heat sink and directly associated heat transport systems for nuclear power plants

    The scope of the Guide covers design considerations for various types of ultimate heat sinks (UHS) and directly associated heat transport systems, and for types and sources of related heat transport fluids. The scope encompasses the conditions for using the UHS for reactor safety following postulated initiating events, as well as its selection, sizing and reliability

  4. Optimal Power Consumption in a Central Heating System with Geothermal Heat Pump

    Tahersima, Fatemeh; Stoustrup, Jakob; Rasmussen, Henrik

    2011-01-01

    Driving a ground source heat pump in a central heating system with the minimum power consumption is studied. The idea of control is based on the fact that, in a heat pump, the temperature of the forward water has a strong positive correlation with the consumed electric power by the compressor. Th...

  5. On the development of an innovative gas-fired heating appliance based on a zeolite-water adsorption heat pump; system description and seasonal gas utilization efficiency

    The main objective of this work is to introduce an innovative hybrid heating appliance incorporating a gas condensing boiler and a zeolite-water adsorption heat pump. The condensing boiler is applied to drive the zeolite-water heat pump for the heating base-load and to assist the heat pump in the so called “mixed operation” mode, in which both the heat pump and the condensing boiler are working in series to cover medium heating demands. Peak heating demands are covered by the condensing boiler in the so called “direct heating” mode. The three operation modes of the hybrid heating appliance have been technically described. In addition, the laboratory test conditions for estimating the seasonal heating performance according to the German Guideline VDI 4650-2 have been introduced. For both heating systems 35/28 °C and 55/45 °C, which represent the typical operating conditions of floor and high temperature radiating heating systems in Europe, seasonal heating gas utilization efficiencies of 1.34 and 1.26 have been measured, respectively with a ground heat source. In two field test installations in one-family houses in Germany, the introduced heating appliance showed 27% more seasonal gas utilization efficiency for heating and domestic hot water production, which is equivalent to a CO2-emission reduction of 20% compared to the gas condensing boiler technology

  6. Installation package for a domestic solar heating and hot water system

    1978-08-01

    Fern Engineering Company, Inc. has developed two prototype solar heating and hot water systems. The systems have been installed at Tunkhannock, Pennsylvania, and Lansing, Michigan. The system consists of the following subsystems: solar collector, storage, control, transport, and auxiliary energy. General guidelines which may be utilized in development of detailed installation plans and specifications are presented. In addition, instruction on operation, maintenance, and repair of a solar heating and hot water system is provided.

  7. Development of the strengthened safeguards system and the Additional Protocol

    For the past 30 years, the IAEA's safeguards system has contributed to the international non-proliferation regime by providing, inter alia, assurances regarding the peaceful uses of declared nuclear material. However, the discovery of a clandestine nuclear weapons program in Iraq in 1991 drew world-wide attention to the need to strengthen the system to address the absence of undeclared nuclear material and activities. Efforts to strengthen the IAEA's safeguards system began in 1991 and culminated in 1997 when the IAEA's Board of Governors approved a Model Protocol Additional to IAEA Safeguards Agreements which greatly expands the legal basis and scope of IAEA safeguards. Within this strengthened system it is expected that the IAEA be able to provide assurance not only of the absence of diversion of declared nuclear material but also on the absence of undeclared nuclear material and activities. This is to be done within a safeguards system that uses an optimal combination of all safeguards measures available, thereby achieving maximum effectiveness and efficiency within the available resources. The paper summarizes the evolution of the safeguards system, describes strengthened safeguards, reports on the status of implementing the strengthening measures, and outlines plans for integrating all available safeguards measures. (author)

  8. Nuclear district-heating system with high-temperature reactor

    A nuclear district-heating system is made up of the following subsystems: nuclear heat-and-power plant, long-distance transfer line, interconnected district heating system, ultimate distribution system to the consumer, and fossil-fired peak-load and standby heating plants. The resons for selecting a district-heating feed temperature of 180degC and the annual performance curve for the interconnected system are presented. The reactor building for the high-temperature reactor is shown and a non-integrated prestressed-concrete vessel is proposed. Burst protection is provided for the coaxial duct and for the steam generator pressure vessel. The costs involved in generating district-heating supplies in the nuclear heat-and-power station are given and they are charged to thermal energy generation in the nuclear heat-and-power station. (M.S.)

  9. Control and energy optimization of ground source heat pump systems for heating and cooling in buildings

    Cervera Vázquez, Javier

    2016-01-01

    [EN] In a context of global warming concern and global energy policies, in which heating and cooling systems in buildings account for a significant amount of the global energy consumption, ground source heat pump (GSHP) systems are widely considered as being among the most efficient and comfortable heating and cooling renewable technologies currently available. Nevertheless, both an optimal design of components and an optimal operation of the system as a whole become crucial so that these ...

  10. Reaction phenomena of catalytic partial oxidation of methane under the impact of carbon dioxide addition and heat recirculation

    The reaction phenomena of CPOM (catalytic partial oxidation of methane) in a Swiss-roll reactor are studied numerically where a rhodium-based catalyst bed is embedded at the center of the reactor. CO2 is added into the feed gas and excess enthalpy recovery is performed to evaluate their influences on CPOM performance. In the study, the mole ratio of O2 to CH4 (O2/CH4 ratio) is fixed at 0.5 and the mole ratio of CO2 to O2 (CO2/O2 ratio) is in the range of 0–2. The results reveal that CO2 addition into the influent has a slight effect on methane combustion, but significantly enhances dry reforming and suppresses steam reforming. The reaction extents of steam reforming and dry reforming in CPOM without heat recovery and CO2 addition are in a comparable state. Once CO2 is added into the feed gas, the dry reforming is enhanced, thereby dominating CH4 consumption. Compared to the reactor without excess enthalpy recovery, heat recirculation drastically increases the maximum reaction temperature and CH4 conversion in the catalyst bed; it also intensifies the H2 selectivity, H2 yield, CO2 conversion, and syngas production rate. The predictions indicate that the heat recirculation is able to improve the syngas formation up to 45%. - Highlights: • Catalytic partial oxidation of methane with CO2 addition and heat recovery is studied. • CO2 addition has a slight effect on methane combustion. • CO2 addition significantly enhances dry reforming and suppresses steam reforming. • Dry reforming dominates CH4 consumption when CO2 addition is large. • Heat recirculation can improve the syngas formation up to 45%

  11. Integrated conceptual design of a robust and reliable waste-heat district heating system

    The various governmental policies aimed at reducing the dependence on fossil fuels for space heating and the reduction in its associated emission of greenhouse gases such as CO2 demands innovative measures. District heating systems using residual industrial waste heats could provide such an efficient method for house and space heating. In such systems, heat is produced and/or thermally upgraded in a central plant and then distributed to the final consumers through a pipeline network. This paper studies the technical, economic, institutional and environmental feasibilities of using low-level residual industrial waste heat for the district heating of Delft, The Netherlands. An integrated conceptual design approach that takes into account both the technical and institutional design of the system has been adopted and has resulted in a feasible and robust system design. The technical part of the integrated conceptual design consisted in the estimation of the heat demands, the design of the heat upgrading system, equipment sizing, the network morphology and/or spatial connectivity and the exergy losses in the needed infrastructure as well as the economic viability of the system. An isopropanol-hydrogen-acetone chemical heat pump was selected for the process and has been modelled in ASPEN plus (registered) . The conventional cost estimation model has been modified to account for uncompensated system downtimes

  12. Experimental study of a photovoltaic solar-assisted heat-pump/heat-pipe system

    A practical design for a heat pump with heat-pipe photovoltaic/thermal (PV/T) collectors is presented. The hybrid system is called the photovoltaic solar-assisted heat-pump/heat-pipe (PV-SAHP/HP) system. To focus on both actual demand and energy savings, the PV-SAHP/HP system was designed to be capable of operating in three different modes, namely, the heat-pipe, solar-assisted heat pump, and air-source heat-pump modes. Based on solar radiation, the system operates in an optimal mode. A series of experiments were conducted in Hong Kong to study the performance of the system when operating in the heat-pipe and the solar-assisted heat-pump modes. Moreover, energy and exergy analyses were used to investigate the total PV/T performance of the system. - Highlights: ► A novel PV-SAHP/HP system with three different operating modes was proposed. ► Performance of the PV-SAHP/HP system was studied experimentally. ► A optimal operating mode of the PV-SAHP/HP system was suggested in this paper.

  13. Monitoring system for the quality assessment in additive manufacturing

    Additive Manufacturing (AM) refers to a process by which a set of digital data -representing a certain complex 3dim design - is used to grow the respective 3dim real structure equal to the corresponding design. For the powder-based EOS manufacturing process a variety of plastic and metal materials can be used. Thereby, AM is in many aspects a very powerful tool as it can help to overcome particular limitations in conventional manufacturing. AM enables more freedom of design, complex, hollow and/or lightweight structures as well as product individualisation and functional integration. As such it is a promising approach with respect to the future design and manufacturing of complex 3dim structures. On the other hand, it certainly calls for new methods and standards in view of quality assessment. In particular, when utilizing AM for the design of complex parts used in aviation and aerospace technologies, appropriate monitoring systems are mandatory. In this respect, recently, sustainable progress has been accomplished by joining the common efforts and concerns of a manufacturer Additive Manufacturing systems and respective materials (EOS), along with those of an operator of such systems (MTU Aero Engines) and experienced application engineers (Carl Metrology), using decent know how in the field of optical and infrared methods regarding non-destructive-examination (NDE). The newly developed technology is best described by a high-resolution layer by layer inspection technique, which allows for a 3D tomography-analysis of the complex part at any time during the manufacturing process. Thereby, inspection costs are kept rather low by using smart image-processing methods as well as CMOS sensors instead of infrared detectors. Moreover, results from conventional physical metallurgy may easily be correlated with the predictive results of the monitoring system which not only allows for improvements of the AM monitoring system, but finally leads to an optimisation of the quality

  14. Monitoring system for the quality assessment in additive manufacturing

    Carl, Volker

    2015-03-01

    Additive Manufacturing (AM) refers to a process by which a set of digital data -representing a certain complex 3dim design - is used to grow the respective 3dim real structure equal to the corresponding design. For the powder-based EOS manufacturing process a variety of plastic and metal materials can be used. Thereby, AM is in many aspects a very powerful tool as it can help to overcome particular limitations in conventional manufacturing. AM enables more freedom of design, complex, hollow and/or lightweight structures as well as product individualisation and functional integration. As such it is a promising approach with respect to the future design and manufacturing of complex 3dim structures. On the other hand, it certainly calls for new methods and standards in view of quality assessment. In particular, when utilizing AM for the design of complex parts used in aviation and aerospace technologies, appropriate monitoring systems are mandatory. In this respect, recently, sustainable progress has been accomplished by joining the common efforts and concerns of a manufacturer Additive Manufacturing systems and respective materials (EOS), along with those of an operator of such systems (MTU Aero Engines) and experienced application engineers (Carl Metrology), using decent know how in the field of optical and infrared methods regarding non-destructive-examination (NDE). The newly developed technology is best described by a high-resolution layer by layer inspection technique, which allows for a 3D tomography-analysis of the complex part at any time during the manufacturing process. Thereby, inspection costs are kept rather low by using smart image-processing methods as well as CMOS sensors instead of infrared detectors. Moreover, results from conventional physical metallurgy may easily be correlated with the predictive results of the monitoring system which not only allows for improvements of the AM monitoring system, but finally leads to an optimisation of the quality

  15. Monitoring system for the quality assessment in additive manufacturing

    Carl, Volker, E-mail: carl@t-zfp.de [Carl Messtechnik, Thyssenstrasse 183a, 46535 Dinslaken (Germany)

    2015-03-31

    Additive Manufacturing (AM) refers to a process by which a set of digital data -representing a certain complex 3dim design - is used to grow the respective 3dim real structure equal to the corresponding design. For the powder-based EOS manufacturing process a variety of plastic and metal materials can be used. Thereby, AM is in many aspects a very powerful tool as it can help to overcome particular limitations in conventional manufacturing. AM enables more freedom of design, complex, hollow and/or lightweight structures as well as product individualisation and functional integration. As such it is a promising approach with respect to the future design and manufacturing of complex 3dim structures. On the other hand, it certainly calls for new methods and standards in view of quality assessment. In particular, when utilizing AM for the design of complex parts used in aviation and aerospace technologies, appropriate monitoring systems are mandatory. In this respect, recently, sustainable progress has been accomplished by joining the common efforts and concerns of a manufacturer Additive Manufacturing systems and respective materials (EOS), along with those of an operator of such systems (MTU Aero Engines) and experienced application engineers (Carl Metrology), using decent know how in the field of optical and infrared methods regarding non-destructive-examination (NDE). The newly developed technology is best described by a high-resolution layer by layer inspection technique, which allows for a 3D tomography-analysis of the complex part at any time during the manufacturing process. Thereby, inspection costs are kept rather low by using smart image-processing methods as well as CMOS sensors instead of infrared detectors. Moreover, results from conventional physical metallurgy may easily be correlated with the predictive results of the monitoring system which not only allows for improvements of the AM monitoring system, but finally leads to an optimisation of the quality

  16. Investigation of Condensation Heat Transfer Correlation of Heat Exchanger Design in Secondary Passive Cooling System

    Recently, condensation heat exchangers have been studied for applications to the passive cooling systems of nuclear plants. To design vertical-type condensation heat exchangers in secondary passive cooling systems, TSCON (Thermal Sizing of CONdenser), a thermal sizing program for a condensation heat exchanger, was developed at KAERI (Korea Atomic Energy Research Institute). In this study, the existing condensation heat transfer correlation of TSCON was evaluated using 1,157 collected experimental data points from the heat exchanger of a secondary passive cooling system for the case of pure steam condensation. The investigation showed that the Shah correlation, published in 2009, provided the most satisfactory results for the heat transfer coefficient with a mean absolute error of 34.8%. It is suggested that the Shah correlation is appropriate for designing a condensation heat exchanger in TSCON

  17. A new heating system based on coupled air source absorption heat pump for cold regions: Energy saving analysis

    Highlights: • A double-stage coupled air source absorption heat pump (ASAHP) is proposed. • The coupled ASAHP exhibits stable and high performance in very cold regions. • Energy-saving rate of the coupled ASAHP in all the typical cities is above 20%. - Abstract: Energy consumption for heating and domestic hot water is very high. The heating system based on an air source absorption heat pump (ASAHP) had been assessed to have great energy saving potential. However, the single-stage ASAHP exhibits poor performance when the outdoor air temperature is very low. A double-stage coupled ASAHP is proposed to improve the energy-saving potential of single-stage ASAHP in cold regions. The heating capacity and primary energy efficiency (PEE) of the proposed system operated in both coupled mode and single-stage mode are simulated under various working conditions. The building load and primary energy consumption of different heating systems applied in cold regions are analyzed comparatively to investigate the energy-saving potential of the coupled ASAHP. Results show that the coupled ASAHP exhibits stable PEE and provides high heating capacity in very cold conditions. The energy-saving rate of the coupled ASAHP in all the typical cities is above 20%. In addition, the energy-saving potential of the single-stage ASAHP in severely cold areas can be improved obviously by coupled ASAHP, with an improvement of 7.73% in Harbin

  18. Laser heat treatment of aerosol-jet additive manufactured graphene patterns

    Jabari, Elahe; Toyserkani, Ehsan

    2015-09-01

    In this article, a laser processing protocol for heat treatment of micro-scale printed graphene patterns is developed, and the results are compared with the counterpart results obtained by the conventional heat treatment process carried out in a furnace. A continuous-wave Erbium fiber laser is used to enhance electrical properties of the aerosol-jet printed graphene patterns through removing solvents and a stabilizer polymer. The laser power and the process speed are optimized to effectively treat the printed patterns without compromising the quality of the graphene flakes. Furthermore, a heat transfer model is developed and its results are utilized to optimize the laser treatment process. It is found that the laser heat treatment process with a laser speed of 0.03 mm s-1, a laser beam diameter ~50 μm, and a laser power of 10 W results in pure graphene patterns with no excessive components. The ratio of D to G bands ({{I}\\text{D}}/{{I}\\text{G}}) in Raman graph of the laser treated pure graphene, which is an indicator of the level of the active defects in graphene structures, is 0.52. The laser treated pure graphene structures also have a C/O ratio and an electrical resistivity of ~4.5 and 0.022 Ω cm, respectively. These values are fairly comparable with the results of samples treated in a furnace. The results suggest that the laser processing has the capability of removing stabilizer polymers and solvents through a localized moving heat source, which is preferable for flexible electronics with low working temperature substrates.

  19. Censored data treatment using additional information in intelligent medical systems

    Zenkova, Z. N.

    2015-11-01

    Statistical procedures are a very important and significant part of modern intelligent medical systems. They are used for proceeding, mining and analysis of different types of the data about patients and their diseases; help to make various decisions, regarding the diagnosis, treatment, medication or surgery, etc. In many cases the data can be censored or incomplete. It is a well-known fact that censorship considerably reduces the efficiency of statistical procedures. In this paper the author makes a brief review of the approaches which allow improvement of the procedures using additional information, and describes a modified estimation of an unknown cumulative distribution function involving additional information about a quantile which is known exactly. The additional information is used by applying a projection of a classical estimator to a set of estimators with certain properties. The Kaplan-Meier estimator is considered as an estimator of the unknown cumulative distribution function, the properties of the modified estimator are investigated for a case of a single right censorship by means of simulations.

  20. The Synergism Between Heat and Mass Transfer Additive and Advanced Surfaces in Aqueous LiBr Horizontal Tube Absorbers

    Miller, W.A.

    1999-03-24

    Experiments were conducted in a laboratory to investigate the absorption of water vapor into a falling-film of aqueous lithium bromide (LiBr). A mini-absorber test stand was used to test smooth tubes and a variety of advanced tube surfaces placed horizontally in a single-row bundle. The bundle had six copper tubes; each tube had an outside diameter of 15.9-mm and a length of 0.32-m. A unique feature of the stand is its ability to operate continuously and support testing of LiBr brine at mass fractions {ge} 0.62. The test stand can also support testing to study the effect of the failing film mass flow rate, the coolant mass flow rate, the coolant temperature, the absorber pressure and the tube spacing. Manufacturers of absorption chillers add small quantities of a heat and mass transfer additive to improve the performance of the absorbers. The additive causes surface stirring which enhances the transport of absorbate into the bulk of the film. Absorption may also be enhanced with advanced tube surfaces that mechanically induce secondary flows in the falling film without increasing the thickness of the film. Several tube geometry's were identified and tested with the intent of mixing the film and renewing the interface with fresh solution from the tube wall. Testing was completed on a smooth tube and several different externally enhanced tube surfaces. Experiments were conducted over the operating conditions of 6.5 mm Hg absorber pressure, coolant temperatures ranging from 20 to 35 C and LiBr mass fractions ranging from 0.60 through 0.62. Initially the effect of tube spacing was investigated for the smooth tube surface, tested with no heat and mass transfer additive. Test results showed the absorber load and the mass absorbed increased as the tube spacing increased because of the improved wetting of the tube bundle. However, tube spacing was not a critical factor if heat and mass transfer additive was active in the mini-absorber. The additive dramatically

  1. List of criteria for additves light heating oil, standard light heating oil, low sulphur light heating oil a bio; Kriterienkatalog fuer Additive Heizoel EL, Standard Heizoel EL, schwefelarm Heizoel EL A Bio

    Lohmann, Gabriele [Innospec Deutschland GmbH, Herne (Germany); Ludzay, Jan [Deutsche Wissenschaftliche Gesellschaft fuer Erdoel, Erdgas und Kohle e.V., Hamburg (Germany)

    2011-10-15

    According to DIN 51603-1 and DIN SPEC 51603-6, the use of additives for quality improvement and control of light heating oil and light heating oil A is approved under certain conditions. In this project, minimum test criteria are established; the compliance with these criteria shall possibly exclude undesired side-effects of the additives used in light heating oil. For these minimum test criteria, test methods were selected and investigated by laboratories with regard to their ability to differentiate and their handling capacity. Against the background that some test methods cannot be applied for the assessment of all heating oil qualities, the established minimum test criteria vary depending on the heating oil quality: Five minimum test criteria were defined for additives to be used in light heating oil according to DIN 51603-1. Four minimum test criteria were established for additives to be applied in light heating oil A Bio according to DIN SPEC 51603-6. This report contains recommendations for the selection of additives. (orig.)

  2. An innovative pool with a passive heat removal system

    Heat removal systems are of primary importance in several industrial processes. As heat sink, a water pool or atmospheric air may be selected. The first solution takes advantage of high heat transfer coefficient with water but it requires active systems to maintain a constant water level; the second solution takes benefit from the unlimited heat removal capacity by air, but it requires a larger heat exchanger to compensate the lower heat transfer coefficient. In NPPs (nuclear power plants) during a nuclear reactor shutdown, as well as in some chemical plants to control runaway reactions, it is possible to use an innovative heat sink that joins the advantages of the two previous solutions. This solution is based on a special heat exchanger submerged in a water pool designed so that when heat removal is requested, active systems are not required to maintain the water level; due to the special design, when the pool is empty, atmospheric air becomes the only heat sink. The special heat exchanger design allows to have a heat exchanger without being oversized and to have a system able to operate for unlimited period without external interventions. This innovative system provides an economic advantage as well as enhanced safety features.

  3. Waste heat conducting system for side burner regenerative coke oven batteries with divided heating system. [German Patent

    Thiersch, F.; Strobel, M.; Schmitz, T.

    1980-08-21

    In the well known waste heat removal system for side burner regenerative coking over batteries with divided heating system both flues could be used simultaneously and equally. The flues in the longitudinal direction of the battery open into a common chimney foot connection at one end of the battery. They are individually connected via opposite groups of transverse flues to opposite groups of waste heat elbows of waste heat valves on the machine and on the coke side.

  4. Integration of large-scale heat pumps in the district heating systems of Greater Copenhagen

    Bach, Bjarne; Werling, Jesper; Ommen, Torben Schmidt;

    2016-01-01

    This study analyses the technical and private economic aspects of integrating a large capacity of electric driven HP (heat pumps) in the Greater Copenhagen DH (district heating) system, which is an example of a state-of-the-art large district heating system with many consumers and suppliers....... The analysis was based on using the energy model Balmorel to determine the optimum dispatch of HPs in the system. The potential heat sources in Copenhagen for use in HPs were determined based on data related to temperatures, flows, and hydrography at different locations, while respecting technical constraints...

  5. Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium.

    Amin Yavari, S; Chai, Y C; Böttger, A J; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

    2015-06-01

    Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20V anodizing time: 30min to 3h) are used for anodizing porous titanium structures that were later heat treated at 500°C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500°C improve the cell culture response of porous titanium. PMID

  6. Application of Predictive Control in District Heating Systems

    Palsson, Olafur Petur; Madsen, Henrik; Søgaard, Henning Tangen

    1993-01-01

    In district heating systems, and in particular if the heat production cakes place at a combined heat and power (CHP) plant, a reasonable control strategy is to keep the supply temperature from the district heating plant as low as possible. However, the control is subject to some restrictions, for...... example, that the total heat requirement for all consumers is supplied at any time and each individual consumer is guaranteed some minimum supply temperature at any time. A lower supply temperature implies lower heat loss from the transport and the distribution network, and lower production costs. A...... district heating system is an example of a non-stationary system, and the model parameters have to be time varying. Hence, the classical predictive control theory has to be modified. Simulation experiments are performed in order to study the performance of modified predictive controllers. The systems ape...

  7. Sensible heat receiver for solar dynamic space power system

    Perez-Davis, Marla E.; Gaier, James R.; Petrefski, Chris

    1991-01-01

    A sensible heat receiver is considered which uses a vapor grown carbon fiber-carbon (VGCF/C) composite as the thermal storage medium and which was designed for a 7-kW Brayton engine. This heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver thermal analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The sensible heat receiver compares well with other latent and advanced sensible heat receivers analyzed in other studies, while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The concept also satisfies the design requirements for a 7-kW Brayton engine system. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material.

  8. Power systems utilizing the heat of produced formation fluid

    Lambirth, Gene Richard

    2011-01-11

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method includes treating a hydrocarbon containing formation. The method may include providing heat to the formation; producing heated fluid from the formation; and generating electricity from at least a portion of the heated fluid using a Kalina cycle.

  9. Rational choice systems control compressor station heat pump

    Чермалых, А.В.; Чермалых, В. М.

    2012-01-01

    Based on the analysis of the heat pump mode, the possible structures of the control electric compressor heat pump installation. Using structural models obtained graphs of the controlled variables. Simulation results are given guidance on the application of rational management systems compressor station, depending on the evaluation criteria and the technological regime of the heat pump

  10. Solar/electric heating systems for the future energy system

    Furbo, Simon; Dannemand, Mark; Perers, Bengt;

    The project “Solar/electric heating systems in the future energy system” was carried out in the period 2008‐2013. The project partners were DTU Byg, DTU Informatics (now DTU Compute), DMI, ENFOR A/S and COWI A/S. The companies Ajva ApS, Ohmatex ApS and Innogie ApS worked together with the project...... partners in two connected projects in order to develop solar/electric heating systems for laboratory tests. The project was financed by the Danish Agency for Science, Technology and Innovation under the Danish Council for Strategic Research in the program Sustainable Energy and Environment. The DSF number...... of the project is 2104‐07‐0021/09‐063201/DSF. This report is the final report of the project. The aim of the project is to elucidate how individual heating units for single family houses are best designed in order to fit into the future energy system. The units are based on solar energy, electrical...

  11. Margins in Swedish district heating systems; Marginaler i Fjaerrvaermesystem

    Selinder, Patrik; Zinko, Heimo [ZW Energiteknik AB, Nykoeping (Sweden)

    2003-03-01

    It can be assumed on good reasons that the Swedish district heating nets are designed with relatively large margins concerning the transportable power. This is done historically to be able to transport the necessary power that can be called for on the coldest winter days but which occur rarely and also due to the former (until 2001) applied recommendations for the dimensioning of hot water flows. The aim of this project was to investigate the possibilities of reducing the connecting power to customers, both from a technical and from the customer point of view. The heating system of a building in Sweden is normally dimensioned according to a certain outdoor air temperature (DUT in Swedish). According to the Swedish Building Code, DUT20 is defined for a given location in such a way that if the heating system is designed for this temperature, the room temperature is allowed to decrease by 3 deg C in the average once in 20 years. That means that for economical reasons, a power deficiency is accounted for in the case of strong cold. The value of DUT is depending on the thermal inertia of the building. Buildings with high thermal inertia can have a higher DUT and vice versa. A reduced system size can in principle mean smaller size of pipes and consumer substations and more power available for additional customers to be connected. In principle, that means a more profitable district heating operation. Besides costs, another problem with oversized capacities are possible operational problems due to slow dynamic system responses, for instance at restarting occasions after a pump stop. A smaller valve size will result in a better system dynamic and may result in a more compliant system operation and increased delivery quality. By choosing just right DUT for every building and abandoning safety margins, it is shown in the report that the connecting power can be reduced in especially medium light to heavy buildings with larger time constants. However, this also means that the

  12. Analysis of Geothermal Heating System for Buildings

    Pal, R. K.

    2013-01-01

    One-third of the world energy utilization is for space heating and cooling. Steady increase in the prices of sources of energy and electricity has resulted in more and more use of alternate sources of energy such as geothermal energy for heating and cooling. Maximum heat loss from the building and water flow rate are for the month of January. The value of maximum heat loss is 3.41 kW and that for water flow rate is 0.84 m3/hrespectively. The maximum savings in terms of value and energy by usi...

  13. Operation of Geothermal Heat System in The Hague, Netherlands; Bedrijfsvoering Aardwarmte Den Haag

    Schoof, F.

    2010-01-15

    Geothermal Heat system The Hague needs a provision in the shape of a geothermal heat system for additional heat supply to approximately 4000 dwellings in the Southwest of The Hague. Some interested persons and residents have questions about the operation of the system, the linkage to the source of geothermal heat, the need for an auxiliary heat boiler, the emission, the operating hours, the noise and the plume formation. This memo contains an explanation of the various components of the geothermal heat plant. [Dutch] Aardwarmte Den Haag (ADH) heeft een voorziening in de vorm van een aardwarmtecentrale nodig voor aanvullende warmtelevering aan circa 4000 woningen in Den Haag Zuid-West. Bij sommige geinteresseerden en omwonenden bestaan vragen over de werking van het systeem, de koppeling met de aardwarmtebron, de noodzaak van een hulpwarmteketel, de uitstoot, de bedrijfsuren, het geluid en de 'pluimvorming'. Deze notitie bevat een toelichting op de verschillende onderdelen van de aardwarmtecentrale.

  14. Addition Theorems, Formal Group Laws and Integrable Systems

    Buchstaber, V. M.; Bunkova, E. Yu.

    2010-11-01

    We consider elliptic curves, given in the Weierstrass parametrization by the equation y2+μ1xy+μ3y = x3+μ2x2+μ4x+μ6. In Tate coordinates t = -x/y and s = -1/y, the geometric addition laws on this curves correspond to the general elliptic formal group law over the ring Z[μ1,μ2,μ3,μ4,μ6]. This formal group law is well-known in the number theory and cryptography. One can find this law in recent works on the theory of elliptic functions and algebraic topology. In the focus of our interest are questions, important from the point of view of Hirzebruch genera and the theory of integrable systems (see references).

  15. Experimental research on LiBr refrigeration - Heat pump system applied in CCHP system

    A new heat recovery technique for a LiBr refrigeration-heat pump system applied in CCHP(Combined Cooling, Heating and Power system) system is proposed in this paper. The system can recover the heat of the LiBr refrigeration cooling water to heat the demineralized water of the boiler. Experimental research on the operating characteristics of the compound system is carried out and the obtained conclusions are as follows: The LiBr refrigeration-heat pump system is able to perform stably and flexibly. The heat pump system has a relative large coefficient of performance (COPP) which can be as high as 6.13. When the outlet temperature of the demineralized water is 67.8 oC, the CCHP system brings 26.6% decrease in primary energy rate consumption compared with the combined heat and power production system (CHP) plus electricity-driven refrigeration. It is suggested that heat pumps should be used in CCHP system to heat the demineralized water of the boiler by recovering the exhaust heat of the LiBr refrigeration system. - Highlights: → LiBr refrigeration-heat pump system applied in CCHP system is proposed. → This system can recover the heat of the LiBr refrigeration cooling water to heat the demineralized water of the boiler. → Using heat pump to recover exhaust heat can increase the energy efficiency of the whole CCHP.

  16. BUYING BEHAVIOUR RELATED TO HEATING SYSTEMS IN GERMANY

    Decker, Thomas; Zapilko, Marina; Menrad, Klaus

    2010-01-01

    The decision for buying a heating system is a long-term one, as many different aspects have an influence on this choice which were analysed in a Germany-wide, written survey. The respondents (only owners of a private house) had to answer questions about their attitude towards e.g. economics, convenience or ecological aspects related to heating systems and the respective combustibles. Using a multinomial logistic regression model the choice of the heating system is mainly explained by ecologic...

  17. Energy efficiency and energy saving in heat supply systems

    Anastasiia Dmitrievna Avsiukevich

    2013-01-01

    The issue of necessity of clear reasoning behind the indicators of efficiency operation of heat supply systems is discussed in the research. The issue of finding out the main methods of improvement of efficiency operation of heat supply systems was also discussed in the work. The analysis of definition of theory of efficiency was carried out. The main indicators of energy saving are introduced. The methods of improvement of efficiency operation of heat supply systems are discussed...

  18. Solar-heating and cooling system design package

    1980-01-01

    Package of information includes design data, performance specifications, drawings, hazard analysis, and spare parts list for commercially produced system installed in single-family dwelling in Akron, Ohio. System uses air flat-plate collectors, 12000 kg rock storage and backup heat pump. Solar portion requires 0.7 kW, and provides 35% of average total heating load including hot water. Information aids persons considering installing solar home-heating systems.

  19. Simulation of a heat pump system for total heat recovery from flue gas

    This paper introduces an approach of using an open-cycle absorption heat pump (OAHP) for recovering waste heat from the flue gas of a gas boiler with a system model. And equivalent energy efficiency is used to evaluate two other heat recovery systems that integrate an electric compression heat pump (EHP) or an absorption heat pump (AHP) with a boiler. The key factors influencing the systems are evaluated. The OAHP system efficiency is improved by 11% compared to the base case. And the OAHP system is more efficient than the AHP or the EHP systems, especially when the solution mass flow rate is only a little less than the cold water mass flow rate. The energy efficiency comparison is supplemented with a simplified economic analysis. The results indicate that the OAHP system is the best choice for the current prices of electricity and natural gas in Beijing. - Highlights: • An OAHP system is analyzed to improve heat recovery from natural gas flue gas. • OAHP system models are presented and analyzed. • The key factors influencing the OAHP systems are analyzed. • The OAHP system is most efficient for most cases compared with other systems. • The OAHP system is more economic than other systems

  20. Fluctuation theorems for excess and housekeeping heats for underdamped systems

    Lahiri, Sourabh; Jayannavar, A. M.

    2013-01-01

    We present a simple derivation of the integral fluctuation theorems for excess housekeeping heat for an underdamped Langevin system, without using the concept of dual dynamics. In conformity with the earlier results, we find that the fluctuation theorem for housekeeping heat holds when the steady state distributions are symmetric in velocity, whereas there is no such requirement for the excess heat. We first prove the integral fluctuation theorem for the excess heat, and then show that it nat...

  1. Assessment of two-level heat pump installations’ power efficiency for heat supply systems

    Аlla Е. Denysova

    2015-06-01

    Full Text Available The problem of energy saving becomes one of the most important in power engineering. It is caused by exhaustion of world reserves in hydrocarbon fuel, such as gas, oil and coal representing sources of traditional heat supply. Conventional sources has essential shortcomings: low power, ecological and economic efficiencies, that can be eliminated by using alternative methods of power supply, like the considered one: low-temperature natural heat of ground waters of on the basis of heat pump installations application. The heat supply system considered provides an effective use of two-level heat pump installation operating as heat source the Odessa city ground waters during the lowest ambient temperature period. Proposed is a calculation method of heat pump installations on the basis of geothermal heat supply. Calculated are the values of electric energy consumption N by the compressors’ drive, and the heat supply system transformation coefficient µ for a source of geothermal heat from ground waters of Odessa city allowing to estimate efficiency of two-level heat pump installations.

  2. Simulation of embedded heat exchangers of solar aided ground source heat pump system

    王芳; 郑茂余; 邵俊鹏; 李忠建

    2008-01-01

    Aimed at unbalance of soil temperature field of ground source heat pump system, solar aided energy storage system was established. In solar assisted ground-source heat pump (SAGSHP) system with soil storage, solar energy collected in three seasons was stored in the soil by vertical U type soil exchangers. The heat abstracted by the ground-source heat pump and collected by the solar collector was employed to heating. Some of the soil heat exchangers were used to store solar energy in the soil so as to be used in next winter after this heating period; and the others were used to extract cooling energy directly in the soil by circulation pump for air conditioning in summer. After that solar energy began to be stored in the soil and ended before heating period. Three dimensional dynamic numerical simulations were built for soil and soil heat exchanger through finite element method. Simulation was done in different strata month by month. Variation and restoration of soil temperature were studied. Economy and reliability of long term SAGSHP system were revealed. It can be seen that soil temperature is about 3 ℃ higher than the original one after one year’s running. It is beneficial for the system to operate for long period.

  3. Theoretical Investigation of the Performance of a Novel Loop Heat Pipe Solar Water Heating System for Use in Beijing, China

    ZHAO, Xudong; Wang, Zhangyuan; Tang, Qi

    2010-01-01

    Abstract A novel loop heat pipe (LHP) solar water heating system for typical apartment buildings in Beijing was designed to enable effective collection of solar heat, distance transport, and efficient conversion of solar heat into hot water. Taking consideration of the heat balances occurring in various parts of the loop, such as the solar absorber, heat pipe loop, heat exchanger and storage tank, a computer model was developed to investigate the thermal performance of the system. ...

  4. Retrofitting Combined Space and Water Heating Systems: Laboratory Tests

    Schoenbauer, B.; Bohac, D.; Huelman, P.; Olson, R.; Hewitt, M.

    2012-10-01

    Better insulated and tighter homes can often use a single heating plant for both space and domestic water heating. These systems, called dual integrated appliances (DIA) or combination systems, can operate at high efficiency and eliminate combustion safety issues associated by using a condensing, sealed combustion heating plant. Funds were received to install 400 DIAs in Minnesota low-income homes. The NorthernSTAR DIA laboratory was created to identify proper system components, designs, operating parameters, and installation procedures to assure high efficiency of field installed systems. Tests verified that heating loads up to 57,000 Btu/hr can be achieved with acceptable return water temperatures and supply air temperatures.

  5. Retrofitting Combined Space and Water Heating Systems. Laboratory Tests

    Schoenbauer, B. [NorthernStar Building America Partnership, St. Paul, MN (United States); Bohac, D. [NorthernStar Building America Partnership, St. Paul, MN (United States); Huelman, P. [NorthernStar Building America Partnership, St. Paul, MN (United States); Olsen, R. [NorthernStar Building America Partnership, St. Paul, MN (United States); Hewett, M. [NorthernStar Building America Partnership, St. Paul, MN (United States)

    2012-10-01

    Better insulated and tighter homes can often use a single heating plant for both space and domestic water heating. These systems, called dual integrated appliances (DIA) or combination systems, can operate at high efficiency and eliminate combustion safety issues associated by using a condensing, sealed combustion heating plant. Funds were received to install 400 DIAs in Minnesota low-income homes. The NorthernSTAR DIA laboratory was created to identify proper system components, designs, operating parameters, and installation procedures to assure high efficiency of field installed systems. Tests verified that heating loads up to 57,000 Btu/hr can be achieved with acceptable return water temperatures and supply air temperatures.

  6. Vapor Compression and Thermoelectric Heat Pump Heat Exchangers for a Condensate Distillation System: Design and Experiment

    Erickson, Lisa R.; Ungar, Eugene K.

    2013-01-01

    Maximizing the reuse of wastewater while minimizing the use of consumables is critical in long duration space exploration. One of the more promising methods of reclaiming urine is the distillation/condensation process used in the cascade distillation system (CDS). This system accepts a mixture of urine and toxic stabilizing agents, heats it to vaporize the water and condenses and cools the resulting water vapor. The CDS wastewater flow requires heating and its condensate flow requires cooling. Performing the heating and cooling processes separately requires two separate units, each of which would require large amounts of electrical power. By heating the wastewater and cooling the condensate in a single heat pump unit, mass, volume, and power efficiencies can be obtained. The present work describes and compares two competing heat pump methodologies that meet the needs of the CDS: 1) a series of mini compressor vapor compression cycles and 2) a thermoelectric heat exchanger. In the paper, the system level requirements are outlined, the designs of the two heat pumps are described in detail, and the results of heat pump performance tests are provided. A summary is provided of the heat pump mass, volume and power trades and a selection recommendation is made.

  7. A heating system for piglets in farrowing house using waste heat from biogas engine

    Payungsak Junyusen

    2008-12-01

    Full Text Available The aim of this study is to design and test a heating system for piglets in farrowing house by utilising the waste heat from a biogas engine as a heat source. The study was separated into three parts: the study on the biogas combined heat and power plant, the investigation on the properties of the heat panel, and the installation and testing of the heating system. From the experiment, the condition producing 60 kW of electrical power was a proper one, in which electrical efficiency and specific fuel consumption were 14% and 1.22 m3/kWh respectively. Generating both electricity and heat increased the overall efficiency to 37.7% and decreased the specific fuel consumption to 0.45 m3/kWh. The heat panel, which was made of a plastic material, had a thermal conductivity of 0.58 W/mC and the maximum compressive force and operating pressure of 8.1 kN and 0.35 bar respectively. The surface temperature of the panel was dependent on the inlet water temperature. When hot water of 44C was supplied into the farrowing house with room temperature of 26C, the average surface temperature was 33C. The developed heating system could provide heat for 4.3 farrowing houses. The payback period of this project was 2.5 years.

  8. System Analysis on Absorption Chiller Utilizing Intermediate Wasted Heat

    Yamada, Miki; Suzuki, Hiroshi; Usui, Hiromoto

    A system analysis has been performed for the multi-effect absorption chiller (MEAC) applied as a bottoming system of 30kW class hybrid system including micro gas turbine (MGT) and solid oxide fuel cell (SOFC) hybrid system. In this paper, an intermediate wasted heat utilization (IWHU) system is suggested for lifting up the energy efficiency of the whole system and coefficient of performance (COP) of MEAC. From the results, the suggested IWHU system was found to show the very high energy efficiency compared with a terminal wasted heat utilization (TWHU) system that uses only the heat exhausted from the terminal of MGT/SOFC system. When TWHU system is applied for MEAC, the utilized heat from the MGT/SOFC system is found to remain low because the temperature difference between the high temperature generator and the wasted heat becomes small. Then, the energy efficiency does not become high in spite of high COP of MEAC. On the other hand, the IWHU system could increase the utilized heat for MEAC as performs effectively. The exergy efficiency of IWHU system is also revealed to be higher than that of a direct gas burning system of MEAC, because the wasted heat is effectively utilized in the IWHU system.

  9. COMPARATIVE EFFICIENCY OF HEAT-PUMPS APPLICATION IN LOW TEMPERATURE HEAT SUPPLY SYSTEMS

    M. N. Chepurnoy; N. V. Resident

    2015-01-01

    The  article  considers  comparative  operation-efficiency  of  the  low-temperature  heatsupply systems with heat pumping plants (HPP) and with hot-water boilers. The paper shows that for energy evaluation of the alternative heat-supply systems effectiveness one cannot employ the transformation ratio (heating coefficient) and the fuel heat-utilization factor in the HPP. Nonetheless the transformation ratio enters the formulae designating the efficiency of HPP operation. The authors obtain a ...

  10. Faxing Structures to the Moon: Freeform Additive Construction System (FACS)

    Howe, A. Scott; Wilcox, Brian; McQuin, Christopher; Townsend, Julie; Rieber, Richard; Barmatz, Martin; Leichty, John

    2013-01-01

    Using the highly articulated All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) robotic mobility system as a precision positioning tool, a variety of print head technologies can be used to 3D print large-scale in-situ structures on planetary surfaces such as the moon or Mars. In effect, in the same way CAD models can be printed in a 3D printer, large-scale structures such as walls, vaults, domes, berms, paving, trench walls, and other insitu derived elements can be FAXed to the planetary surface and built in advance of the arrival of crews, supplementing equipment and materials brought from earth. This paper discusses the ATHLETE system as a mobility / positioning platform, and presents several options for large-scale additive print head technologies, including tunable microwave "sinterator" approaches and in-situ concrete deposition. The paper also discusses potential applications, such as sintered-in-place habitat shells, radiation shielding, road paving, modular bricks, and prefabricated construction components.

  11. Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium

    Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20 V anodizing time: 30 min to 3 h) are used for anodizing porous titanium structures that were later heat treated at 500 °C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55 nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500 °C improve the cell culture response of porous titanium

  12. Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium

    Amin Yavari, S., E-mail: s.aminyavari@tudelft.nl [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Chai, Y.C. [Prometheus, Division of Skeletal Tissue Engineering, Bus 813, O& N1, Herestraat 49, KU Leuven, 3000 Leuven (Belgium); Tissue Engineering Laboratory, Skeletal Biology and Engineering Research Center, Bus 813, O& N1, Herestraat 49, KU Leuven, 3000 Leuven (Belgium); Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Böttger, A.J. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Wauthle, R. [KU Leuven, Department of Mechanical Engineering, Section Production Engineering, Machine Design and Automation (PMA), Celestijnenlaan 300B, 3001 Leuven (Belgium); 3D Systems — LayerWise NV, Grauwmeer 14, 3001 Leuven (Belgium); Schrooten, J. [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 — PB2450, B-3001 Heverlee (Belgium); Weinans, H. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Department of Orthopedics and Dept. Rheumatology, UMC Utrecht, Heidelberglaan100, 3584CX Utrecht (Netherlands); Zadpoor, A.A. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands)

    2015-06-01

    Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20 V anodizing time: 30 min to 3 h) are used for anodizing porous titanium structures that were later heat treated at 500 °C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55 nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500 °C improve the cell culture response of porous titanium

  13. Effect of additional element and heat treating temperature on micro-structure and mechanical behavior of Ag alloy thin film

    JU Dong-ying; ISHIGURO S; ARIZONO T; HASEGAWA K

    2006-01-01

    For Ag alloy film used for the storage media,it is required to have heat-resistance,anti-constant temperature and anti-constant humidity characteristics,corrosion resistance,while high reflectivity over Al is maintained. An Ag alloy thin film (additive element Pd,Cu,P) was created on glass substrates,and various heat treatment was conducted. Then,fine structure was observed on this thin film using AFM,and fine structure evaluation of the inside was carried out by the in-plane diffractometry and X-ray diffractometry,and in addition,residual stress analysis was carried out. These results were compared and were examined,and fine structure and physical property in a metallic thin film were evaluated,and usefulness of evaluation method was verified.

  14. Active heat exchange system development for latent heat thermal energy storage

    Lefrois, R.T.; Knowles, G.R.; Mathur, A.K.; Budimir, J.

    1979-02-01

    The report describes active heat exchange concepts for use with thermal energy storage systems in the temperature range of 250/sup 0/C to 350/sup 0/C, using the heat of fusion of molten salts for storing thermal energy. It identifies over 25 novel techniques for active heat exchange thermal energy storage systems. Salt mixtures that freeze and melt in appropriate ranges are identified and are evaluated for physico-chemical, economic, corrosive and safety characteristics. Eight active heat exchange concepts for heat transfer during solidification are conceived and conceptually designed for use with selected storage media. The concepts are analyzed for their scalability, maintenance, safety, technological development and costs. A model for estimating and scaling storage system costs is developed and is used for economic evaluation of salt mixtures and heat exchange concepts for a large scale application. The importance of comparing salts and heat exchange concepts on a total system cost basis, rather than the component cost basis alone, is pointed out. Comparison of these costs with current state-of-the-art systems should be avoided due to significant differences in developmental status. The heat exchange concepts were sized and compared for 6.5 MPa/281/sup 0/C steam conditions and a 1000 MW(t) heat rate for six hours. A cost sensitivity analysis for other design conditions is also carried out. The study resulted in the selection of a shell and coated-tube heat exchanger concept and a direct contact-reflux boiler heat exchange concept. For the storage medium, a dilute eutectic mixture of 99 wt % NaNO/sub 3/ and 1 wt % NaOH is selected for use in experimenting with the selected heat exchanger concepts in subsequent tasks.

  15. [Carbon monoxide poisoning by a heating system].

    Dietz, Eric; Gehl, Axel; Friedrich, Peter; Kappus, Stefan; Petter, Franz; Maurer, Klaus; Püschel, Klaus

    2016-01-01

    A case of accidental carbon monoxide poisoning in several occupants of two neighboring residential buildings in Hamburg-Harburg (Germany) caused by a defective gas central heating system is described. Because of leaks in one of the residential buildings and the directly adjacent wall of the neighboring house, the gas could spread and accumulated in both residential buildings, which resulted in a highly dangerous situation. Exposure to the toxic gas caused mild to severe intoxication in 15 persons. Three victims died still at the site of the accident. Measures to protect the occupants were taken only with a great delay. As symptoms were unspecific, it was not realized that the various alarms given by persons involved in the accident were related to the same cause. In order to take appropriate measures in time it is indispensible to recognize, assess and check potential risks, which can be done by using carbon monoxide warning devices and performing immediate COHb measurements with special pulse oximeters on site. Moreover, the COHb content in the blood should be routinely determined in all patients admitted to an emergency department with unspecific symptoms. PMID:27120897

  16. Conventional heating systems is heating with geothermal water, v. 15(60)

    The Geothermal Energy (GE) is a new renewable energy source with many advantages and specifics. Present mainly application of GE is in agriculture. In Geothermal System Kochani the GE uses for district heating and industrial uses also. There are many problems to solve before using the geothermal energy for district heating: direct application feasibility for heating rooms and industrial using existing heating installation system (90/70°C); the level of heating needs covering without installation reconstruction; techno-economical justification of this reconstruction ; covering of pike heating needs. The answers of these enigmas you have in this written effort. The results were practically justified in about ten object in Kochani. (Author)

  17. Conventional heating systems is heating with geothermal water, v. 15(59)

    The Geothermal Energy (GE) is a new renewable energy source with many advantages and specifics. Present mainly application of GE is in agriculture. In Geothermal System Kochani the GE uses for district heating and industrial uses also. There are many problems to solve before using the geothermal energy for district heating: direct application feasibility for heating rooms and industrial using existing heating installation system (90/70°C); the level of heating needs covering without installation reconstruction; techno-economical justification of this reconstruction ; covering of pike heating needs. The answers of these enigmas you have in this written effort. The results were practically justified in about ten object in Kochani. (Author)

  18. Performance improvement of a 330MWe power plant by flue gas heat recovery system

    Xu Changchun

    2016-01-01

    Full Text Available In a utility boiler, the most heat loss is from the exhaust flue gas. In order to reduce the exhaust flue gas temperature and further boost the plant efficiency, an improved indirect flue gas heat recovery system and an additional economizer system are proposed. The waste heat of flue gas is used for high-pressure condensate regeneration heating. This reduces high pressure steam extraction from steam turbine and more power is generated. The waste heat recovery of flue gas decreases coal consumption. Other approaches for heat recovery of flue gas, direct utilization of flue gas energy and indirect flue gas heat recovery system, are also considered in this work. The proposed systems coupled with a reference 330MWe power plant are simulated using equivalent enthalpy drop method. The results show that the additional economizer scheme has the best performance. When the exhaust flue gas temperature decreases from 153℃ to 123℃, power output increases by 6.37MWe and increment in plant efficiency is about 1.89%. For the improved indirect flue gas heat recovery system, power output increases by 5.68MWe and the increment in plant efficiency is 1.69%.

  19. Magnetocaloric heat pump device, a heating or cooling system and a magnetocaloric heat pump assembly

    2014-01-01

    The invention provides a magnetocaloric heat pump device, comprising a magnetocaloric bed; a magnetic field source, the magnetocaloric bed and the magnetic field source being arranged to move relative to each other so as to generate a magnetocaloric refrigeration cycle within the heat pump, wherein...

  20. Emulsifying properties and oil/water (O/W) interface adsorption behavior of heated soy proteins: effects of heating concentration, homogenizer rotating speed, and salt addition level.

    Cui, Zhumei; Chen, Yeming; Kong, Xiangzhen; Zhang, Caimeng; Hua, Yufei

    2014-02-19

    The adsorption of heat-denatured soy proteins at the oil/water (O/W) interface during emulsification was studied. Protein samples were prepared by heating protein solutions at concentrations of 1-5% (w/v) and were then diluted to 0.3% (w/v). The results showed that soy proteins that had been heated at higher concentrations generated smaller droplet size of emulsion. Increase in homogenizer rotating speed resulted in higher protein adsorption percentages and lower surface loads at the O/W interface. Surface loads for both unheated and heated soy proteins were linearly correlated with the unadsorbed proteins' equilibrium concentration at various rotating speeds. With the rise in NaCl addition level, protein adsorption percentage and surface loads of emulsions increased, whereas lower droplet sizes were obtained at the ionic strength of 0.1 M. The aggregates and non-aggregates displayed different adsorption behaviors when rotating speed or NaCl concentration was varied. PMID:24460091

  1. Solar dynamic heat rejection technology. Task 1: System concept development

    Gustafson, Eric; Carlson, Albert W.

    1987-01-01

    The results are presented of a concept development study of heat rejection systems for Space Station solar dynamic power systems. The heat rejection concepts are based on recent developments in high thermal transport capacity heat pipe radiators. The thermal performance and weights of each of the heat rejection subsystems is addressed in detail, and critical technologies which require development tests and evaluation for successful demonstration are assessed and identified. Baseline and several alternate heat rejection system configurations and optimum designs are developed for both Brayton and Rankine cycles. The thermal performance, mass properties, assembly requirements, reliability, maintenance requirements and life cycle cost are determined for each configuration. A specific design was then selected for each configuration which represents an optimum design for that configuration. The final recommendations of heat rejection system configuration for either the Brayton or Rankine cycles depend on the priorities established for the evaluation criteria.

  2. A study of a small nuclear power plant system for district heating

    We have studied nuclear power plant for district heating. Already some towns and villages in Hokkaido have requested small reactor for district heating. Using existing technology allows us to shorten development period and to keep a lid on development cost. We decided to develop new reactor based on 'MUTSU' reactor technology because 'MUTSU' had already proved its safety. And this reactor was boron free reactor. It allows plant system to reduce the chemical control system. And moderator temperature coefficient is deeply negative. It means to improve its operability and leads to dependability enhancement. We calculated burn-up calculation of erbium addition fuel. In the result, the core life became about 10 years. And we adapt the cassette type refueling during outagein in order to maintain nonproliferation. In the district heating system, a double heat exchanger system enables to response to load change in season. To obtain the acceptance of public, this system has a leak prevention system of radioactive materials to public. And road heating system of low grade heat utilization from turbine condenser leads to improve the heat utilization efficiency. We carried out performance evaluation test of district heating pipeline. Then the heat loss of pipeline is estimated at about 0.440degC/km. This result meets general condition, which is about 1degC/km. This small plant has passive safety system. It is natural cooling of containment vessel. In case of loss of coolant accident, decay heat can remove by natural convection air cooling after 6 hours. Decay heat within 6 hours can remove by evaporative heat transfer of pool on containment vessel. (author)

  3. Thermoelectric and heat flow phenomena in mesoscopic systems

    Matthews, Jason E.

    Low-dimensional electronic systems, systems that are restricted to single energy levels in at least one of the three spatial dimensions, have attracted considerable interest in the field of thermoelectric materials. At these scales, the ability to manipulate electronic energy levels offers a great deal of control over a device's thermopower, that is, its ability to generate a voltage due to a thermal gradient. In addition, low-dimensional devices offer increased control over phononic heat flow. Mesoscale geometry can also have a large impact on both electron and phonon dynamics. Effects such as ballistic transport in a two-dimensional electron gas structure can lead to the enhancement or attenuation of electron transmission probabilities in multi-terminal junctions. The first half of this dissertation investigates the transverse thermoelectric properties of a four-terminal ballistic junction containing a central symmetry-breaking scatterer. It is believed that the combined symmetry of the scatterer and junction is the key component to understanding non-linear and thermoelectric transport in these junctions. To this end, experimental investigations on this type of junction were carried out to demonstrate its ability to generate a transverse thermovoltage. To aid in interpreting the results, a multi-terminal scattering-matrix theory was developed that relates the junction's non-linear electronic properties to its thermoelectric properties. The possibility of a transverse thermoelectric device also motivated the first derivation of the transverse thermoelectric efficiency. This second half of this dissertation focuses on heat flow phenomena in InAs/InP heterostructure nanowires. In thermoelectric research, a phononic heat flow between thermal reservoirs is considered parasitic due to its minimal contribution to the electrical output. Recent experiments involving heterostructure nanowires have shown an unexpectedly large heat flow, which is attributed in this

  4. Development of Vertical Ground Heat Exchanger for Ground-Source Heat Pump System

    Jalaluddin

    2012-01-01

    ABSTRACT: Geothermal energy as environmentally friendly energy source with wide range of applications such as for space heating and cooling, hot water supply and applications in the agricultural field has been used in practical engineering. The well-known application is for space heating and cooling in residential and commercial buildings with using ground-source heat pump (GSHP) system. An advantage of using the geothermal energy is the stability of the temperature range of ground at tens...

  5. The Added Economic and Environmental Value of Solar Thermal Systems in Microgrids with Combined Heat and Power

    Marnay, Chris

    2010-01-01

    The addition of solar thermal and heat storage systems can improve the economic, as well as environmental attraction of micro-generation systems, e.g. fuel cells with or without combined heat and power (CHP) and contribute to enhanced CO2 reduction. However, the interactions between solar thermal collection and storage systems and CHP systems can be complex, depending on the tariff structure, load profile, etc. In order to examine the impact of solar thermal and heat storage on CO2 emissions ...

  6. Modelling temperature dynamics of a district heating system in Naestved, Denmark-A case study

    Modelling the temperature dynamics of a district heating system is typically validated for a single pipe or a system with limited information about dynamic consumer behaviour. In the present work, time dependent consumer data from the Naestved district heating system was used to investigate the ability of modelling tools to represent the temperature profile distortion throughout an entire heating system network. The Naestved district heating subsystem was modelled by two approaches (the node method developed at the Technical University of Denmark and the software TERMIS), and these modelling results were compared with measured data. The results indicate that the discrepancies between the predicted and measured temperatures are pronounced for consumers located in pipelines at distant pipelines containing numerous bends and fittings. Additionally, it was found that representing the consumer behaviour on an annual average basis introduced a deviation between the predicted and the measured return temperatures at the heat source

  7. Present status and future perspective of nuclear heat application systems

    Inaba, Yoshitomo; Fumizawa, Motoo; Hishida, Makoto [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1996-05-01

    We need to intensely investigate real possibilities of nuclear heat application systems which exploit high potential of nuclear energy as a promising candidate of the future energy resource in the world. In this paper, we considered social, economical, technical conditions necessary for the development of nuclear heat application systems. We also investigated several nuclear heat application systems which reform coal into traffic fuel like hydrogen, methane and methanol, and discussed advantages and disadvantages of the systems. We showed it was possible to reduce carbon dioxide emission of the systems compared with old systems, but we found carbon dioxide tax was the key issue from the viewpoint of economical competitiveness. (author).

  8. Effects of Ce-rich RE additions and heat treatment on the microstructure and tensile properties of Mg-Li-Al-Zn-based alloy

    Research highlights: → Adding Ce-rich RE leads to the formation of Al2RE/Al3RE phases in LAZ532 alloy. → Ce-rich RE additions improve the tensile properties of the alloy. → The tensile properties of alloys processed by heat treatment are increased greatly. → Adding RE changes the fracture pattern of the alloy. - Abstract: As-cast Mg-5Li-3Al-2Zn-xRE (x = 0-2.5 wt.%) alloys were prepared under the ambient of pure argon, and the effects of Ce-rich rare earths (RE) and heat treatment on the microstructure and mechanical properties of Mg-Li-Al-Zn-based alloy were investigated. The results show that the main phase compositions of Mg-5Li-3Al-2Zn (LAZ532) alloy consist of α-Mg and AlLi. With the addition of RE, Al-RE precipitate forms, and increases gradually, whereas AlLi phase decreases. The room temperature tensile test reveals that the addition of RE could clearly improves the mechanical properties of alloys which are further improved after heat treatment. In more detail, excellent tensile strength and ductility are obtained in 1.5 wt.% RE containing alloy in as-cast state. After heat treatment, the 1.0 wt.% RE containing alloy attains superior tensile strength. The differences in tensile strength are related to the morphology, distribution of second phases and solid-solution strengthening in different alloy systems. In addition, the fracture pattern of the alloy is predominantly brittle cleavage and tends to be quasi-cleavage with RE addition.

  9. Applicability of sewage heat pump air-conditioning system

    陈金华; 刘猛; 刘勇; 靳鸣; 陈洁

    2009-01-01

    A sewage heat pump system and its application based on a project in Chongqing,China,were discussed. Based on the sewage conditions,a feasibility analysis of the sewage heat pump air conditioning system was conducted. The theoretical and quantitative calculations indicate that sewage flux in the city sewage main pipe in the project can satisfy heat exchange requirements,and taking water from the pipes has relatively small influence on the pipe net in summer and winter. The sewage heat pump air-conditioning system can save 21.5% operating cost in one year,which is energy efficient and environmentally friendly.

  10. Residential heat pumps in the future Danish energy system

    Petrovic, Stefan; Karlsson, Kenneth Bernard

    2016-01-01

    . The improved modelling of residential heat pumps proved to have influence on the results. First, it would be optimal to invest in more ground-source heat pumps, but there is not enough available ground area. Second, the total system costs are higher when COPs are modelled as temperature......Denmark is striving towards 100% renewable energy system in 2050. Residential heat pumps are expected to be a part of that system.We propose two novel approaches to improve the representation of residential heat pumps: Coefficients of performance (COPs) are modelled as dependent on air and ground...

  11. Advanced Supermarket Refrigeration/Heat Recovery Systems. Country Report, Denmark

    Knudsen, Hans-Jørgen Høgaard; Christensen, K. G.

    Annex 26 is the first international project under the IEA Heat Pump Programme that links refrigeration and heat pump technology. Recovering heat from advanced supermarket refrigeration systems for space and water heating seems obvious and is beneficial for owners and operators. Because the great...... number of supermarkets that offer frozen and chilled food and further growth of this sector may be expected, the amount of energy used for refrigeration is enormous and will likely increase in the near future. Annex 26 analysed several advanced supermarket refrigeration systems and came to remarkable...... provide valuable information for practitioners (designers, installers) and manufactures of supermarket refrigeration systems....

  12. Simultaneous power generation and heat recovery using a heat pipe assisted thermoelectric generator system

    Highlights: • A new passive power cogeneration system using industrial waste heat was introduced. • Heat pipes and thermoelectrics were used for recovering waste heat and electricity. • Theoretical model predicted the 2 kW test rig could recover 1.345 kW thermal power. • 10.39 W electrical power was produced equivalent to 0.77% conversion efficiency. - Abstract: This research explores a new method of recovering waste heat and electricity using a combination of heat pipes and thermoelectric generators (HP-TEG). The HP-TEG system consists of Bismuth Telluride (Bi2Te3) based thermoelectric generators (TEGs), which are sandwiched between two finned heat pipes to achieve a temperature gradient across the TEG for thermoelectricity generation. A theoretical model was developed to predict the waste heat recovery and electricity conversion performances of the HP-TEG system under different parametric conditions. The modelling results show that the HP-TEG system has the capability of recovering 1.345 kW of waste heat and generating 10.39 W of electrical power using 8 installed TEGs. An experimental test bench for the HP-TEG system is under development and will be discussed in this paper

  13. Optimization of Developing Heat Supply System in Competitive Market Environment

    V. A. Stennikov; O. V. Khamisov; A. V. Penkovsky

    2013-01-01

    The paper is aimed at working out the mathematical models and methods to solve the problems of operation of developing heat supply systems in a competitive market environment. The formation of new principles of functioning in this field is conditioned by the market mechanisms emerging due to the interaction between different owners of heat economy facilities within the single system. Today heat energy markets are represented by a great number of enterprises with different types of ownership t...

  14. Generalized Performance Characteristics of Refrigeration and Heat Pump Systems

    Mahmoud Huleihil; Bjarne Andresen

    2010-01-01

    A finite-time generic model to describe the behavior of real refrigeration systems is discussed. The model accounts for finite heat transfer rates, heat leaks, and friction as different sources of dissipation. The performance characteristics are cast in terms of cooling rate (r) versus coefficient of performance (w). For comparison purposes, various types of refrigeration/heat pump systems are considered: the thermoelectric refrigerator, the reverse Brayton cycle, and the reverse Rankine ...

  15. External costs and taxes in heat supply systems

    A systems approach was used to compare different heating systems from a consumer perspective. The whole energy system was considered from natural resources to the required energy services. District heating, electric heat pumps, electric boilers, natural-gas-, oil- or pellet-fired local boilers were considered when supplying heat to a detached house. The district heat production included wood-chip-fired and natural-gas-fired cogeneration plants. Electricity other than cogenerated electricity was produced in wood-chip- and natural-gas-fired stand-alone power plants. The analysis includes four tax scenarios, as well as the external cost of environmental and health damage arising from energy conversion emission based on the ExternE study of the European Commission. The most cost-efficient systems were the natural-gas and oil boiler systems, followed by the heat pump and district heating systems, when the external cost and taxes were excluded. When including the external costs of CO2 emission, the wood-fuel-based systems were much more cost efficient than the fossil-fuel-based systems, also when CO2 capture and storage were applied. The external costs are, however, highly uncertain. Taxes steer towards lowering energy use and lowering CO2 emission if they are levied solely on all the fossil-fuel-related emission and fuel use in the systems. If consumer electricity and heat taxes are used, the taxes have an impact on the total cost, regardless of the fuel used, thereby benefiting fuel-based local heating systems. The heat pump systems were the least affected by taxes, due to their high energy efficiency. The electric boiler systems were the least cost-efficient systems, also when the external cost and taxes were included

  16. Performance analysis of different high-temperature heat pump systems for low-grade waste heat recovery

    Different heat pump systems were used to recover the heat from waste water with mean temperature of 45 °C and produce hot water with the temperature up to 95 °C. Those systems include single-stage vapor compression heat pump (system 1), two-stage heat pump with external heat exchanger (system 2), two-stage heat pump with refrigerant injection (system 3), two-stage heat pump with refrigerant injection and internal heat exchanger (system 4), two-stage heat pump with flash tank (system 5) and two-stage heat pump with flash tank and intercooler (system 6). Thermodynamic and economic analyses were conducted to compare the performance of each system. Results showed that the COP and exergy efficiency for both system 5 and system 6 are quite close, and much higher than those of other systems. Besides, the payback period of both system 5 and system 6 are also shorter as compared to other systems. Considering both the thermodynamic performance and economic quality of the system, system 5 is finally preferred since less initial investment is required for system 5 as compared to system 6. - Highlights: • Different heat pump systems were introduced to recover the heat of waste water. • Thermodynamic and economic performances of those systems were analyzed and compared. • The two-stage heat pump system with flash tank was preferred

  17. Formation and reduction of carcinogenic furan in various model systems containing food additives.

    Kim, Jin-Sil; Her, Jae-Young; Lee, Kwang-Geun

    2015-12-15

    The aim of this study was to analyse and reduce furan in various model systems. Furan model systems consisting of monosaccharides (0.5M glucose and ribose), amino acids (0.5M alanine and serine) and/or 1.0M ascorbic acid were heated at 121°C for 25 min. The effects of food additives (each 0.1M) such as metal ions (iron sulphate, magnesium sulphate, zinc sulphate and calcium sulphate), antioxidants (BHT and BHA), and sodium sulphite on the formation of furan were measured. The level of furan formed in the model systems was 6.8-527.3 ng/ml. The level of furan in the model systems of glucose/serine and glucose/alanine increased 7-674% when food additives were added. In contrast, the level of furan decreased by 18-51% in the Maillard reaction model systems that included ribose and alanine/serine with food additives except zinc sulphate. PMID:26190608

  18. Mirror Advanced Reactor Study (MARS) plasma heating systems

    Plasma heating systems are critical to the operation of a high Q tandem mirror reactor. Two electron cyclotron resonance heating (ECRH) systems, a high energy negative ion-based neutral beam, and an anchor ion cyclotron resonance heating (ICRH) system create the proper axial density, pressure and potential profiles in the endcells. The proper profiles electrostatically plug the central cell plasma, and provide an adequate margin with respect to MHD- and micro-stability for the device. An ICRH system in the central cell is also required to heat the plasma to ignition. Each MARS plasma heating system is at a higher power than that has yet been utilized in any fusion experiments; the use of innovative concepts has lead to compact, efficient, and affordable ECRH and negative beam systems. (orig.)

  19. Hydro-Quebec REC system: probe positioning system for heat exchanger inspection

    In 2002, Hydro-Quebec's Gentilly-2 (G2) Nuclear Power Plant commissioned the Hydro-Quebec Research Institute to integrate its SCOMPI technology into their Eddy Current heat exchanger inspection setup. The purpose of this project was to develop an automated, fast, precise, and reliable positioning device, which would be adaptable to several heat exchangers, including steam generators. Hydro-Quebec's SCOMPI robot is a portable, six axes robot, developed in 1992 for the repair and maintenance of turbine runners. Given the name 'REC System', the integrated SCOMPI robot was first used during the 2003 moderator and shut-down cooler heat exchanger inspections. In 2005, the REC System replaced its SCOMPI technology with that of the newer Mini-SCOMPI, and was afterwards used to inspect two G2 steam generators. The Mini-SCOMPI is a smaller version of the SCOMPI which allows one-man, quick and easy installation. Both the 2003 and the 2005 campaigns were successful, with the REC system integration proving to be nearly transparent to the inspection process. No failure or time losses occurred during these inspections and all of the heat exchangers' tubes were accessible. In addition, probe positioning was very efficient thanks to the Mini-SCOMPI and the vision system. In 2005, half of the tubes belonging to Steam Generators 1 and 2 were inspected from the inlet side. In the future, all heat exchanger inspections with the REC System will be performed using the Mini-SCOMPI. The 5th CNS International Steam Generator Conference provides us with an excellent forum for presenting the successful integration of a new technology into an existing system for the inspection of various types of heat exchangers. (author)

  20. Heat storage systems. 5. rev. ed.; Waermespeicher

    Hauer, Andreas [ZAE Bayern, Garching (Germany); Hiebler, Stefan [ZAE Bayern, Garching (Germany). Gruppe Waermespeichersysteme; Reuss, Manfred [ZAE Bayern (Germany). Arbeitsgruppe Solarthermie/Oberflaechennahe Geothermie

    2013-11-01

    Heat storages provide a means of adapting heat supply to demand both over time and in terms of quantity. Efficient heat storages are a prerequisite for making cost-effective use of waste and solar heat. The BINE reference book presents different storage technologies, offering planners, consultants and real estate professionals an overview of different storage media, capacity categories and types, these including long-term as well as high-temperature storages, along with information on economic efficiency. [German] Waermespeicher ermoeglichen es, das Waermeangebot im Zeitverlauf und in der Leistung dem Bedarf anzupassen. Erst durch effiziente Waermespeicher lassen sich Abwaerme oder solare Waerme wirtschaftlich nutzen. Das BINE-Fachbuch stellt die verschiedenen Speichertechnologien vor und bietet Planern, Beratern und der Immobilienwirtschaft einen Ueberblick ueber unterschiedliche Speichermedien, -groessen und -typen, Langzeit- und Hochtemperaturspeicher und die Wirtschaftlichkeit.

  1. Analytical and experimental studies of heat pipe radiation cooling of hypersonic propulsion systems

    Martin, R. A.; Merrigan, M. A.; Elder, M. G.; Sena, J. T.; Keddy, E. S.; Silverstein, C. C.

    1992-01-01

    Analytical and experimental studies were completed to assess the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This new approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal radiation from an external heat pipe nacelle. For propulsion systems using heat pipe radiation cooling (HPRC), it is possible to continue to use hydrocarbon fuels into the Mach 4 to Mach 6 speed range, thereby enhancing the economic attractiveness of commercial or military hypersonic flight. In the second-phase feasibility program recently completed, it is found that heat loads produced by considering both convection and radiation heat transfer from the combustion gas can be handled with HPRC design modifications. The application of thermal insulation to ramburner and nozzle walls was also found to reduce the heat load by about one-half and to reduce peak HPRC system temperatures to below 2700 F. In addition, the operation of HPRC at cruise conditions of around Mach 4.5 and at an altitude of 90,000 ft lowers the peak hot-section temperatures to around 2800 F. An HPRC heat pipe was successfully fabricated and tested at Mach 5 conditions of heat flux, heat load, and temperature.

  2. An investigation of energy efficient and sustainable heating systems for buildings : Combining photovoltaics with heat pump

    Hesaraki, Arefeh; Holmberg, Sture

    2013-01-01

    Renewable energy sources contribute considerable amounts of energy when natural phenomena are converted into useful forms of energy. Solar energy, i.e. renewable energy, is converted to electricity by photovoltaic systems (PV). This study was aimed at investigating the possibility of combining PV with Heat Pump (HP) (PV-HP system). HP uses direct electricity to produce heat. In order to increase the sustainability and efficiency of the system, the required electricity for the HP was supposed ...

  3. Combustion Air Pre-heating from Ash Sensible Heat in Municipal Waste Incineration Systems

    Zakariya Kaneesamkandi

    2014-01-01

    Heat recovery from bottom ash is more important in municipal waste combustion systems than in any other solid fuel combustion since almost 50% of it comprises of non-combustibles. In this study, an ash cooling system using air as the cooling medium has been modeled for pre-heating the combustion air. Air cooling has several advantages over water cooling methods. The study involves modeling using Gambit tool and is solved with the fluent solver. Municipal solid waste incineration systems have ...

  4. Heat pipe gas combustion system endurance test for Stirling engine

    Mahrle, P.

    1990-12-01

    Stirling Thermal Motors, Inc. has been developing a general purpose Heat Pipe Gas Combustion (HPGC) system suitable for use with the STM4-120 Stirling engine. The HPGC consists of a parallel plate recuperative preheater, a finned heat pipe evaporator, and a film-cooled gas combustor. The principal component is the heat pipe evaporator which collects and distributes the liquid sodium over the heat transfer surfaces. The liquid sodium evaporates and flows to the condensers where it delivers its latent heat. Given here are the test results of the endurance tests run on a Gas Fired Stirling Engine (GFSE).

  5. Experiments on novel solar heating and cooling system

    Solar heating and nocturnal radiant cooling techniques are united to produce a novel solar heating and cooling system. The radiant panel with both heating and cooling functions can be used as structural materials for the building envelope, which realizes true building integrated utilization of solar energy. Based on the natural circulation principle, the operation status can be changed automatically between the heating cycle and the cooling cycle. System performances under different climate conditions using different covers on the radiant panel are studied. The results show that the novel solar heating and cooling system has good performance of heating and cooling. For the no cover system, the daily average heat collecting efficiency is 52% with the maximum efficiency of 73%, while at night, the cooling capacity is about 47 W/m2 on a sunny day. On a cloudy day, the daily average heat collecting efficiency is 47% with the maximum of 84%, while the cooling capacity is about 33 W/m2. As a polycarbonate (PC) panel or polyethylene film are used as covers, the maximum heat collecting efficiencies are 75% and 72% and the daily average heat collecting efficiencies are 61% and 58%, while the cooling capacities are 50 W/m2 and 36 W/m2, respectively

  6. Prototype solar heating and cooling systems including potable hot water

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  7. Analysis of thermosyphon heat exchangers for use in solar domestic hot water heating systems

    Dahl, Scott David

    1998-11-01

    A recent innovation in the solar industry is the use of thermosyphon heat exchangers. Determining the performance of these systems requires knowledge of how thermosyphon flow rate and heat exchanger performance vary with operating conditions. This study demonstrates that several thermosyphon heat exchanger designs operate in the laminar mixed convection regime. Empirical heat transfer and pressure drop correlations are obtained for three tube-in-shell heat exchangers (four, seven, and nine tube). Thermosyphon flow is on the shell side. Correlations are obtained with uniform heat flux on the tube walls and with a mixture of glycol and water circulating inside the tubes. Ranges of Reynolds, Prandtl, and Grashof numbers are 50 to 1800, 2.5 and 6.0, and 4×105 to 1×108, respectively. Nusselt number correlations are presented in a form that combines the contributions of forced and natural convection, Nu4Mixed=Nu4Forced+Nu4Natural. The Nusselt number is influenced by natural convection when the term Raq0.25/(Re0.5Pr0.33) is greater than unity. Pressure drop through these three designs is not significantly affected by mixed convection because most pressure drop losses are at the heat exchanger inlet and outlet. A comparison and discussion of the performance of several other heat exchanger designs (tube-in-shell and coil-in- shell designs) are presented. Generally, the coil-in- shell heat exchangers perform better than the tube-in- shell heat exchangers. Data from all heat exchanger designs is used to develop a new one-dimensional model for thermosyphon heat exchangers in solar water heating systems. The model requires two empirically determined relationships, pressure drop as a function of water mass flow rate and the overall heat transfer coefficient-area product (UA) as a function of Reynolds, Prandtl, and Grashof number. A testing protocol is presented that describes the procedure to obtain the data for the correlations. Two new TRNSYS component models are presented

  8. Combustion Air Pre-heating from Ash Sensible Heat in Municipal Waste Incineration Systems

    Zakariya Kaneesamkandi

    2014-01-01

    Full Text Available Heat recovery from bottom ash is more important in municipal waste combustion systems than in any other solid fuel combustion since almost 50% of it comprises of non-combustibles. In this study, an ash cooling system using air as the cooling medium has been modeled for pre-heating the combustion air. Air cooling has several advantages over water cooling methods. The study involves modeling using Gambit tool and is solved with the fluent solver. Municipal solid waste incineration systems have the advantage of being located near the waste collection area apart from the high volume reduction ratio. Improvements in the emission control systems and combustion technology can make incineration a highly feasible disposal method. Low furnace temperature due to heat losses through fuel moisture loss and ash sensible heat loss has been a disadvantage with these systems. In this study, a small percentage of the combustion air is pre-heated in a non-contact type heat exchanger and its effect on the available energy of combustion gases at the evaporator outlet is studied. The study is performed for two different waste samples. Results indicate significant increase in available energy at the evaporator outlet and better relative performance for the lower grade fuel. A comparison is made with similar methods reported in the literature along with a brief discussion on the methodologies adopted. The results confirm the importance of installing ash sensible heat recovery mechanism for waste incineration systems as well as the feasibility of the air based method.

  9. Heat pipe radiators for solar dynamic space power system heat rejection

    Gustafson, Eric; Carlson, Albert

    1987-01-01

    The paper presents the results of a concept development study of heat rejection systems for Space Station solar dynamic power systems. The thermal performance and weights of each of the heat rejection subsystems have been addressed in detail, and critical technologies which require development tests and evaluation for successful demonstration were assessed and identified. Baseline and several alternate heat rejection system configurations and optimum designs were developed for both Brayton and Rankine cycles. The thermal performance, mass properties, assembly requirements, reliability, maintenance requirements, and life cycle costs were determined for each of the system configurations. Trade studies were performed on each configuration with respect to the heat pipe wall thickness and the amount of redundancy to determine the effects on system reliability, maintenance requirements, and life cycle costs. An optimum design was then selected for each configuration.

  10. Heating and Domestic Hot Water Systems in Buildings Supplied by Low-Temperature District Heating

    Brand, Marek

    District heating (DH) systems supplied by renewable energy sources are one of the main solutions for achieving a fossil-free heating sector in Denmark by 2035. To reach this goal, the medium temperature DH used until now needs to transform to a new concept reflecting the requirement for lower heat...... loss from DH networks required by the reduced heating demand of low-energy and refurbished buildings combined with the lower supply temperatures required by using renewable heat sources. Both these needs meet in the recently developed concept of low-temperature DH designed with supply....../return temperatures as low as 50°C/25°C and highly insulated pipes with reduced inner diameter. With this design, the heat loss from the DH networks can be reduced to one quarter of the value for traditional DH designed and operated for temperatures of 80°C/40°C. However, such low temperatures bring challenges...

  11. Characterization of a mini-channel heat exchanger for a heat pump system

    In this paper a mini-channel aluminum heat exchanger used in a reversible heat pump is presented. Mini-channel finned heat exchangers are getting more and more interest for refrigeration systems, especially when compactness and low refrigerant charge are desired. Purpose of this paper was to characterize the mini-channel heat exchanger used as evaporator in terms of heat transfer performance and to study the refrigerant distribution in the manifold. The heat exchanger characterization was performed experimentally by means of a test rig built up for this purpose. It is composed of an air-to-air heat pump, air channels for the external and internal air circulation arranged in a closed loop, measurement sensors and an acquisition system. The overall heat transfer capacity was assessed. Moreover, in order to characterize the flow field of the refrigerant in the manifold of the heat exchanger, a numerical investigation of the fluid flow by means of CFD was performed. It was meant to evaluate the goodness of the present design and to identify possible solutions for the future improvement of the manifold design.

  12. Characterization of a mini-channel heat exchanger for a heat pump system

    Arteconi, A.; Giuliani, G.; Tartuferi, M.; Polonara, F.

    2014-04-01

    In this paper a mini-channel aluminum heat exchanger used in a reversible heat pump is presented. Mini-channel finned heat exchangers are getting more and more interest for refrigeration systems, especially when compactness and low refrigerant charge are desired. Purpose of this paper was to characterize the mini-channel heat exchanger used as evaporator in terms of heat transfer performance and to study the refrigerant distribution in the manifold. The heat exchanger characterization was performed experimentally by means of a test rig built up for this purpose. It is composed of an air-to-air heat pump, air channels for the external and internal air circulation arranged in a closed loop, measurement sensors and an acquisition system. The overall heat transfer capacity was assessed. Moreover, in order to characterize the flow field of the refrigerant in the manifold of the heat exchanger, a numerical investigation of the fluid flow by means of CFD was performed. It was meant to evaluate the goodness of the present design and to identify possible solutions for the future improvement of the manifold design.

  13. Analysis of the location for peak heating in CHP based combined district heating systems

    Combined heat and power (CHP) is the main technology for providing the base load of district heating in China. However, CHP is not efficient for providing the peak load; instead, a peak boiler with high efficiency could be used to compensate the peak load. This paper studies how the location of the peak boiler can affect the energy efficiency and economic performance of such CHP based combined district heating system. Firstly, the connection mode and the control strategy for different peak heating locations are analyzed. Then the effect of the peak boiler's location on the initial investment of the network and the cost for distributing heat is studied. The objective is to place the peak boiler in a location where the overall costs are the smallest. Following this rule, the results indicate that the peak boiler should be located at the CHP plant if that allows using cheaper ‘self-use electricity’ in CHP for distributing the heat. However, if the market electricity price is used everywhere, or if energy efficiency is more emphasized, the location of the peak boiler should be closer to the users with dense heat loads. - Highlights: • Location for peak heating in the CHP based combined DH system is studied. • Regulation or control strategies for combined DH are summarized. • The heat load duration curve for combined DH is demonstrated. • Network design for combined DH with peak boiler outside of the CHP is analyzed

  14. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods.

    Kou, Xiao-Xi; Li, Rui; Hou, Li-Xia; Huang, Zhi; Ling, Bo; Wang, Shao-Jin

    2016-01-01

    Knowledge of bacteria's heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria's heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample's thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS's performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria's thermo-tolerances. PMID:27465120

  15. Effect of solution heat treatment and additives on the microstructure of Al - Si (A413.1) automotive alloys

    Moustafa, M.A. [Central Metallurgical Research and Development Inst., Helwan, Cairo (Egypt); Dept. des Sciences appliquees, Univ. du Quebec a Chicoutimi, Chicoutimi (Canada); Samuel, F.H. [Dept. des Sciences appliquees, Univ. du Quebec a Chicoutimi, Chicoutimi (Canada); Doty, H.W. [GM Powertrain Group, Metal Casting Technology, Inc., Milford, NH (United States)

    2004-07-01

    A study was carried out to determine the role of additives such as Mg and Cu on the microstructural characteristics of grain refined, Sr-modified eutectic A413.1 alloy (Al-11.7% Si) during solution heat treatment. For comparison purposes, some of the alloys were also studied in the non-modified condition. The alloys were cast in a steel permanent mold preheated at 425 C that provided a microstructure with an average dendrite arm spacing (DAS) of {proportional_to}22 {mu}m. Castings were solution heat treated at 500 {+-} 2 C for time up 24 h, followed by quenching in warm water (at 60 C). Microstructural analysis of the as-cast and heat-treated castings was carried out using optical microscopy in conjunction with image analysis. Phase identifications were done using the electron probe microanalysis (EPMA) technique. In the as-cast condition, the addition of 0.42 wt% Mg to the unmodified alloy produced relatively arge Si particles compared to the base A413.1 alloy. The Si particle size remained more or less the same with increase in solution treatment time and Mg level. Both Mg{sub 2}Si and Al{sub 2}Cu phases were observed to dissolve almost completely after 8 h solution time, while the Al{sub 5}Cu{sub 2}Mg{sub 8}Si{sub 6} phase was found to persist even after 24 h. (orig.)

  16. Effects of Heat Addition After the Exhaust Valve on a Small Turbocharged Diesel Engine

    Brandon, Sidney Jordan

    2006-01-01

    Designers of engines have always looked for ways to improve the power to weight ratio of mobile internal combustion engines. This was especially true in aircraft engine design and engines for various forms of racing. Today designers are looking for ways to make everything from cars to road tractors to farm tractors lighter and thereby more efficient. In addition, in many cases these vehicles only need the maximum power that an engine can produce for a small amount of time. What is needed is ...

  17. Solar heating and cooling technical data and systems analysis

    Christensen, D. L.

    1977-01-01

    The research activities described herein were concentrated on the areas of economics, heating and cooling systems, architectural design, materials characteristics, climatic conditions, educational information packages, and evaluation of solar energy systems and components.

  18. Preliminary design package for prototype solar heating and cooling systems

    1978-01-01

    A summary is given of the preliminary analysis and design activity on solar heating and cooling systems. The analysis was made without site specific data other than weather; therefore, the results indicate performance expected under these special conditions. Major items include a market analysis, design approaches, trade studies and other special data required to evaluate the preliminary analysis and design. The program calls for the development and delivery of eight prototype solar heating and cooling systems for installation and operational test. Two heating and six heating and cooling units will be delivered for Single Family Residences, Multiple-family Residences and commercial applications.

  19. Design of annual storage solar space heating systems

    Hooper, F.C.; Cook, J.D.

    1979-11-01

    Design considerations for annual storage solar space heating systems are discussed. A simulation model for the performance of suh systems is described, and a method of classifying system configurations is proposed. It is shown that annual systems sized for unconstrained performance, with no unused collector or storage capacity, and no rejected heat, minimize solar acquisition costs. The optimal performance corresponds to the condition where the marginal storage-to-collector sizing ratio is equal to the corresponding marginal cost ratio.

  20. Active heat exchange system development for latent heat thermal energy storage

    Lefrois, R. T.; Knowles, G. R.; Mathur, A. K.; Budimir, J.

    1979-01-01

    Active heat exchange concepts for use with thermal energy storage systems in the temperature range of 250 C to 350 C, using the heat of fusion of molten salts for storing thermal energy are described. Salt mixtures that freeze and melt in appropriate ranges are identified and are evaluated for physico-chemical, economic, corrosive and safety characteristics. Eight active heat exchange concepts for heat transfer during solidification are conceived and conceptually designed for use with selected storage media. The concepts are analyzed for their scalability, maintenance, safety, technological development and costs. A model for estimating and scaling storage system costs is developed and is used for economic evaluation of salt mixtures and heat exchange concepts for a large scale application. The importance of comparing salts and heat exchange concepts on a total system cost basis, rather than the component cost basis alone, is pointed out. The heat exchange concepts were sized and compared for 6.5 MPa/281 C steam conditions and a 1000 MW(t) heat rate for six hours. A cost sensitivity analysis for other design conditions is also carried out.

  1. Heat transfer and fluid flow in nuclear systems

    The present publication is an attempt to provide a bridge between fundamental principles and current design practice. It is intended to serve the need of: engineers, scientists and graduate students active in thermal and hydraulics problems and to those interested to keep abreast of the field. The text is addressed to readers with previous knowledge in heat transfer and fluid flow equvalent to a one year university graduate course in that field. Because of the high degree of specialization covered in the six chapters of the book, individual authors of international reputation and active in their respective area of specialization were selected to contribute their knowledge. Each of the six chapters or sub-chapters are self-contained. They are followed by problem sets to enable the reader to check his level of comprehension of the material presented. The nuclear systems covered in separate chapters include: the pressurized and boiling water reactors (PWR, BWR), the helium cooled high temperature reactors (HTGR and HTR), the breeders helium cooled (GCFR) and sodium cooled (LMFBR). In addition the heat-exchangers and steam generators commonly associated with the above systems are covered in Chapter 6

  2. Operation Performance of Air Source Heat Pump System for Space Heating in Tianjin

    ZHAO Jun; CHEN Yan; QU Hang; LI Xinguo

    2007-01-01

    An air source heat pump system (ASHPS) used in an office building is set up and studied experimentally. Its operating performance in winter is evaluated based on test data and a comparative discussion is given on the effect of climate conditions and heating load ratio on the operation behavior.Then heating capacity variation caused by evaporator frosting is analyzed as well. Finally, the defrosting parameters and the technical feasibility are studied for a constant heating demand. The experimental results indicate that both the outlet water temperature drop and the system COP should be taken into account when setting defrosting parameters, and ASHPS is a viable technology for space heating and hotwater production in winter in Tianjin, which can maintain the room temperature above 19 ℃ when the outdoor temperature is -2 ℃.

  3. Building integration of concentrating solar systems for heating applications

    A new solar collection system integrated on the façade of a building is investigated for Dutch climate conditions. The solar collection system includes a solar façade, a receiver tube and 10 Fresnel lenses. The Fresnel lenses Fresnel lenses considered were linear, non-imaging, line – focused with a system tracking the position of the sun that ensures vertical incidence of the direct solar radiation on the lenses. For the heating system a double-effect absorption heat pump, which requires high temperature of the heating fluid, was used, working with water and lithium-bromide as refrigerant and solution respectively. The Fresnel lens system is connected with the absorption heat pump through a thermal energy storage tank which accumulates the heat from the Fresnel lens system to provide it to the high pressure generator of the absorption heat pump. - Highlights: • The integration of Fresnel lenses in solar thermal building façades is investigated. • Using building integrated Fresnel lenses, 43% heating energy can be saved. • Energy savings in Mediterranean countries are significantly larger. • The absorption heat pump could make great contribution to energy savings for Dutch climate conditions

  4. Hybrid Ventilation with Innovative Heat Recovery—A System Analysis

    Bengt Hellström

    2013-02-01

    Full Text Available One of the most important factors when low energy houses are built is to have good heat recovery on the ventilation system. However, standard ventilation units use a considerable amount of electricity. This article discusses the consequences on a system level of using hybrid ventilation with heat recovery. The simulation program TRNSYS was used in order to investigate a ventilation system with heat recovery. The system also includes a ground source storage and waste water heat recovery system. The result of the analysis shows that the annual energy gain from ground source storage is limited. However, this is partly a consequence of the fact that the well functioning hybrid ventilation system leaves little room for improvements. The analysis shows that the hybrid ventilation system has potential to be an attractive solution for low energy buildings with a very low need for electrical energy.

  5. Experimental study of the solar district heating system

    Baek, Nam-Choon; Jin-Kook, Lee; Eung-Sang, Yoon; Mun-Chang, Joo [Korea Inst. of Energy Research, Yusung, Daejeon (Korea, Republic of); Shin, U-Chul [Daejeon Univ., Dong-gu, Daejeon (Korea, Republic of); Yoon, Seok-Man [Korea District Heating Co. (Korea, Republic of)

    2008-07-01

    This study was carried out the performance analysis of district solar heating system which was installed in Bundang district heating area in the end of 2006. The flat plate and vacuum tube solar collector are combined in one system. So district heating water is heated first by flat plate solar collector and than by vacuum tube solar collector. This solar heating system has not a solar buffer tank and is operating with variable flow rate to obtain a setting temperature of 85{proportional_to}95 C. As a result, the daily solar thermal collection efficiency is about 30 to 40% for the plate type and 50 to 57% for the evacuated type solar collector. It varied especially depend on the weather condition like as solar radiation and ambient temperature. This variable flow rate system can be also reduced much pumping power more than 50%. (orig.)

  6. Flathead Electric Cooperative Facility Geothermal Heat Pump System Upgrade

    Liu, Xiaobing [Oak Ridge National Lab

    2014-06-01

    High initial cost and lack of public awareness of ground source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects have been competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This paper highlights findings of a case study of one of the ARRA-funded GSHP demonstration projects, which is a heating only central GSHP system using shallow aquifer as heat source and installed at a warehouse and truck bay at Kalispell, MT. This case study is based on the analysis of measured performance data, utility bills, and calculations of energy consumptions of conventional central heating systems for providing the same heat outputs as the central GSHP system did. The evaluated performance metrics include energy efficiency of the heat pump equipment and the overall GSHP system, pumping performance, energy savings, carbon emission reductions, and cost-effectiveness of GSHP system compared with conventional heating systems. This case study also identified areas for reducing uncertainties in performance evaluation, improving operational efficiency, and reducing installed cost of similar GSHP systems in the future. Publication of ASHRAE at the annual conference in Seattle.

  7. Flathead Electric Cooperative Facility Geothermal Heat Pump System Upgrade.

    Liu, Xiaobing [Oak Ridge National Lab

    2014-06-01

    High initial cost and lack of public awareness of ground source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects have been competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This paper highlights findings of a case study of one of the ARRA-funded GSHP demonstration projects, which is a heating only central GSHP system using shallow aquifer as heat source and installed at a warehouse and truck bay at Kalispell, MT. This case study is based on the analysis of measured performance data, utility bills, and calculations of energy consumptions of conventional central heating systems for providing the same heat outputs as the central GSHP system did. The evaluated performance metrics include energy efficiency of the heat pump equipment and the overall GSHP system, pumping performance, energy savings, carbon emission reductions, and cost-effectiveness of GSHP system compared with conventional heating systems. This case study also identified areas for reducing uncertainties in performance evaluation, improving operational efficiency, and reducing installed cost of similar GSHP systems in the future. Publication of ASHRAE at the annual conference in Seattle June 2014.

  8. Theoretical energy and exergy analyses of solar assisted heat pump space heating system

    Atmaca Ibrahim

    2014-01-01

    Full Text Available Due to use of alternative energy sources and energy efficient operation, heat pumps come into prominence in recent years. Especially in solar-assisted heat pumps, sizing the required system is difficult and arduous task in order to provide optimum working conditions. Therefore, in this study solar assisted indirect expanded heat pump space heating system is simulated and the results of the simulation are compared with available experimental data in the literature in order to present reliability of the model. Solar radiation values in the selected region are estimated with the simulation. The case study is applied and simulation results are given for Antalya, Turkey. Collector type and storage tank capacity effects on the consumed power of the compressor, COP of the heat pump and the overall system are estimated with the simulation, depending on the radiation data, collector surface area and the heating capacity of the space. Exergy analysis is also performed with the simulation and irreversibility, improvement potentials and exergy efficiencies of the heat pump and system components are estimated.

  9. Optimized shape of system for levitation heating

    Mach, M.; Ulrych, B.; Doležel, Ivo; Nečesaný, Jakub

    Poznan: Poznan University of Technology, 2006 - (Nawrowski, R.), s. 192-204 ISBN 83-922049-3-X Institutional research plan: CEZ:AV0Z20570509 Keywords : levitation induction heating * electromagnetic field * temperature field Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  10. Performance of Space Heating in a Modern Energy System

    Elmegaard, Brian

    2011-01-01

    In the paper we study the performance of a number of heat supply technologies. The background of the study is the changes in the Danish energy systems over the last three decades which have caused integration of large shares of combined heat and power (CHP), renewable fuels and wind power. These ...... the technologies with best performance, unless we consider solar heating and biomass from the viewpoints of CO2 emissions and fossil fuel consumption....

  11. Commercial high efficiency dehumidification systems using heat pipes

    1993-09-01

    An improved heat pipe design using separately connected two-section one-way flow heat pipes with internal microgrooves instead of wicks is described. This design is now commercially available for use to increase the dehumidification capacity of air conditioning systems. The design also includes a method of introducing fresh air into buildings while recovering heat and controlling the humidity of the incoming air. Included are applications and case studies, load calculations and technical data, and installation, operation, and maintenance information.

  12. An Integrated Control System for Heating and Indoor Climate Applications

    Tahersima, Fatemeh

    2012-01-01

    In the present study, we investigated modeling and control of hydronic heat emitters integrated with a ground-source heat pump. Optimization of the system performance in terms of energy efficiency, associated energy cost and occupants' thermal comfort is the main objective to be fulfilled via de-sign of an integrated controller. We also proposed control strategies to manage energy consumption of the building to turn domestic heat demands into a flexible load in the smart electricity grid. We ...

  13. TO THE SUBJECT OF DEVELOPMENT OF POWER SUPPLY PROCESS FOR INDUSTRIAL HEAT TECHNOLOGIES AND HEAT SUPPLY SYSTEMS IN BELARUS

    B. M. Khrоustalev

    2015-02-01

    Full Text Available Considers the current key energy problem – the rational and efficient use of energy resources, and the possibility of its solution, based on the concept of intensive energy conservation. As a result, the way of primary energy consumption reduction in Belarus is provided. The initial situation in the frame of program of further improvement of energy consumption until 2030 is estimated. It is shown, that for Belarus the first place in energy saving measures takes the efficiency improvement of natural gas consumption, what allows reducing the investment and saving energy resources.The possibility of usage of waste energy flows of medium-and low-temperature from industrial and municipal enterprises are discussed. To realize the described possibilities, some changes of heat supply system of enterprises and plants are required. Changes in heat supply system of the industrial enterprises, related with usage of low-temperature waste energy flows in a thermal energy generation process for heating, require the installation of additional equipment in existing heat energy supply system, such as absorption heat pumps, which are easily joint and successfully work at boiler Houses as well as at CHP. The numerous examples of fuel consumption reduction via heat industrial waste and sewage usage are shown in this article. It must be emphasized, that such an expansion of energy-saving framework not only reduce the primary energy consumption by heat generating sources, but also significantly improves the conditions of the Belarusian electrical grid operation under the conditions of nuclear power plant commissioning. The existing technical framework, that ensured the proposed changes, is also taking into account.

  14. Radio frequency auxiliary heating systems design in ITER

    A combination of radio frequency (RF) auxiliary heating systems will provide at least one half of the required 100 MW of auxiliary power in ITER. Five of the 20 equatorial ports are assigned to RF heating systems. Recent work has focused on developing an integrated equatorial port-plug design concept for all of the RF auxiliary heating systems as well as other equatorial port systems such as diagnostics. Common features of the design approach include the use of identical interfaces to services such as cooling water, vacuum, mechanical connection to the vessel, and maintenance. Based on the integrated port concept, a high level of design integration has been achieved for the RF heating systems. Implementation of the integrated design concept has been accomplished without significantly affecting the individual system performance and with limited impact on the torus layout. (author)

  15. Optimum structural design of a heat exchanger for gas-circulation systems

    Highlights: • The fluid flow structure and heat transfer characters of a finned-tube heat exchanger was numerically investigated. • The optimized heat exchanger is more compact and easy to be miniaturized and utilized. • A novel configuration of tubes region is proposed to reduce the pressure drop penalty of the optimized heat exchanger. • The comprehensive performance of the optimized heat exchanger is enhanced. - Abstract: T-type gas-circulation systems are widely used in gas lasers to remove waste heat from the discharge process. The structure of the heat exchanger is a very important factor that affects the performance of a T-type gas-circulation system. To develop a high-performance heat exchanger for such a gas-circulation application, a computational fluid dynamics approach was adopted for this study. A three-dimensional numerical model was established. A detailed study focused on the influence of the shape of the channel and the location of the finned tubes on the performance of the heat exchanger. Based on the heat-transfer characteristics and the flow structure, a novel geometric structure was proposed to reduce the volume of the heat exchanger. Comprehensive simulations to determine the optimum locations for the finned tubes were also conducted. As a result of this optimization, the heat exchanger for a T-type gas-circulation system could be made more compact and its pressure loss penalty decreased by 11.5% even though its heat-transfer ability remained unchanged. In addition, the results of a theoretical analysis and numerical simulation were found to be in good agreement with the results of the experiment, indicating the validity of the results of the research

  16. Experimental Study of the Performance of Air Source Heat Pump Systems Assisted by Low-Temperature Solar-Heated Water

    Jinshun Wu; Chao Chen; Song Pan; Jun Wei; Tianquan Pan; Yixuan Wei; Yunmo Wang; Xinru Wang; Jiale Su

    2013-01-01

    Due to the low temperatures, the heating efficiency of air source heat pump systems during the winter is very low. To address this problem, a low-temperature solar hot water system was added to a basic air source heat pump system. Several parameters were tested and analyzed. The heat collection efficiency of the solar collector was analyzed under low-temperature conditions. The factors that affect the performance of the heat pumps, such as the fluid temperature, pressure, and energy savings, ...

  17. Predicting the Heat Consumption in District Heating Systems using Meteorological Forecasts

    Nielsen, Henrik Aalborg, orlov 31.07.2008; Madsen, Henrik

    Methods for on-line prediction of heat consumption in district heating systems hour by hour for horizons up to 72 hours are considered in this report. Data from the district heating system Vestegnens Kraftvarmeselskab I/S is used in the investigation. During the development it has been assumed...... predictions is 3.8% for data in November, 1995 (17% when no climate information is used). However, at some occasions large deviations occur and in January 1996 a value of 5.5% is obtained. The relative prediction error tends to increase with decreasing heat consumption. Approaches to implementation...... are suggested in a separate chapter of the report. The methods of prediction applied are based on adaptive estimation, whereby the methods adapt to slow changes in the system. This approach is also used to track the transition from e.g. warm to cold periods. Due to different preferences of the households...

  18. Characteristics of cooling water fouling in a heat exchange system

    This study investigated the efficiency of the physical water treatment method in preventing and controlling fouling accumulation on heat transfer surfaces in a laboratory heat exchange system with tap and artificial water. To investigate the fouling characteristics, an experimental test facility with a plate type heat exchange system was newly built, where cooling and hot water moved in opposite directions forming a counter-flow heat exchanger. The obtained fouling resistances were used to analyze the effects of the physical water treatment on fouling mitigation. Furthermore, the surface tension and pH values of water were also measured. This study compared the fouling characteristics of cooling water in the heat exchange system with and without the mitigation methods for various inlet velocities. In the presence of the electrode devices with a velocity of 0.5m/s, the fouling resistance was reduced by 79% compared to that in the absence of electrode devices

  19. Development of a combined heat exchanger design concept for an SFR decay heat removal system

    A fast neutron spectrum reactor is one of the most promising options for efficient uranium resources utilization and a substantial reduction of radioactive waste to be disposed. To this end, the Korea Atomic Energy Research Institute (KAERI) has developed the own sodium cooled fast reactor(SFR) design concept since 1992, and recent efforts putting into this area have been focused on enhancement of plant safety complying with the lessons learned from the Fukushima nuclear power plant accident. In particular, a reliable decay heat removal (DHR) becomes one of the most important tasks in successful SFR design. Therefore, to achieve more reliable DHR performance, KAERI has developed the innovative design concept called the PDRC, which is similar to conventional DRACS but its detailed flow path inside the reactor vessel is very creative. The schematic of the heat transport system in DSFR 600 is depicted in Figure 1 as an example. In regard to the DHR operation, the internal flow path passing through the reactor core should be maintained at all time but, in accident conditions, converted from the normal heat transport mode using the intermediate heat transport system (IHTS) to the alternate path with the DRACS loops. If the normal heat transport path via the IHTS is not available, the DRACS shall substitute the normal path and remove total heat load including core decay and sensible heat from the primary sodium pool. Since heat rejection from the intermediate heat exchanger (IHX) is not guaranteed in this situation, the decay heat exchanger (DHX) becomes the only heat sink and thus its arrangement inside the reactor vessel plays an important role in determining DHR capability. In the current SFR design, however, the internal flow path from the hot pool to the cold pool is somewhat ambiguous due to the split flow ratio formed in a parallel path between IHXs and DHXs. This ambiguity results in a large uncertainty in DHX shell side flowrate and corresponding heat transfer

  20. Additive manufacturing of Co-Cr-Mo alloy: Influence of heat treatment on microstructure, tribological and electrochemical properties

    Kedar Mallik Mantrala

    2015-03-01

    Full Text Available Co-Cr-Mo alloy samples, fabricated using Laser Engineered Net Shaping – a laser based additive manufacturing technology, have been subjected heat treatment to study its influence on microstructure, wear and corrosion properties. Following L9 Orthogonal array of Taguchi method, the samples were solutionized at 1200oC for 30, 45 and 60 min followed by water quenching. Ageing treatment was done at 815oC and 830oC for 2, 4 and 6 h. Heat treated samples were evaluated for their microstructure, hardness, wear resistance and corrosion resistance. The results revealed that highest hardness of 512 ± 58 Hv and wear rate of 0.90 ± 0.14 × 10-4 mm3/N.m can be achieved with appropriate post-fabrication heat treatment. ANOVA and grey relational analysis on the experimental data revealed that the samples subjected to solution treatment for 60 min, without ageing, exhibit best combination of hardness, wear and corrosion resistance.

  1. Zinc Oxide Nanoparticles Prepared By a Simple Heating: Effect of Polymer Addition and Polymer Absence on the Morphology

    Mikrajuddin Abdullah

    2004-11-01

    Full Text Available Zinc oxide (ZnO nanoparticles were prepared by a simple heating of precursors in a furnace at temperatures of below 1000˚C in an air environment. If zinc nitrate was used as precursor, polymer (e.g., polyethylene glycol (PEG must be added into the precursor to produce ZnO in nanometer size. The absence of polymer led to the presence of several micrometer-sized flakes. In addition, the heating temperatures must be higher than 500˚C to completely decompose the organic material in final product. However, if zinc acetate was used as precursor, nanometer-sized ZnO having a high crystallinity can be obtained even when the polymer was absent. Interestingly, we also found that heating at low temperatures (e.g. 400˚C resulted in ZnO nanorods with an elongation ratio of around 5. This method is rapid, economically efficient, and readily scalable for industrial applications.

  2. Effect of Zr addition on phase constitution and heat treatment behavior of Ti-25mass%Nb alloys

    In an attempt to optimize the shape recovery temperature, the effect of Zr addition on phase constitution and heat treatment behavior is investigated by electrical resistivity and Vickers hardness (HV) measurements, X-ray diffractometry (XRD) and shape recovery tests. Ti-25mass%Nb-0, 2, 7 and 12mass%Zr alloys (abbreviated as 0Zr, 2Zr, 7Zr and 12Zr, respectively) were prepared using an arc-furnace. Specimens were solution-treated at 1273 K for 3.6 ks and then quenched by iced water (STQ). STQed specimens were isochronally heat-treated. In 0Zr and 2Zr, only the orthorhombic martensite phase α'' was identified by XRD, while the two-phase alloys α'' and β were identified in 7Zr and 12Zr. In 7Zr, resistivity at liquid nitrogen and room temperature (ρLN and ρRT, respectively) and resistivity ratio (ρLN/ρRT) drastically increased at 523 K because of the reverse-transformation of α'' into β phase. Thereafter, resistivity and resistivity ratio decreased with increasing heat treatment temperature due to isothermal ω precipitation. Starting temperature of shape recovery is 623 K in 7Zr and 523 K in 12Zr. In 7Zr, shape recovery ratio is about 80% at 723 K, which is the maximum obtained in this study. (orig.)

  3. CHARACTERISTICS OF FLUORIDE EMISSION FROM FIVE CLAY MINERALS AS AFFECTED BY TEMPERATURE,HEATING TIME AND ADDITION OF CALCIUM COMPOUNDS

    2001-01-01

    Characteristics of fluoride emission from five clay minerals (montmorillonite, kaolinite, vermiculite, geothite, and allophane) as affected by temperature, heating time and addition of calcium compounds were studied. Marked increase of the fluoride emission rate was noticed with increase of temperature. The fluoride release, began at 500 ℃-600 ℃, and the main bulk of the fluoride emission occurred at the temperature of about 800 ℃. The loss of crystalline water was primarily responsible for the increase of fluoride emission. When minerals were heated at 800 ℃, The fluoride emission rate from the clay minerals reached the highest after heating for 1 hour. The samples treated by CaO, CaCO3, Ca(OH)2, Ca3(PO4)2, and CaSO4 had 55.45%, 59.58%, 46.45%, 54.31%, 31.25% reduction in the fluoride emission from montmorillonite at the temperature of 800 ℃, respectively. CaCO3 had the highest fluoride fixing capacity compared to other calcium compounds.

  4. Device with Complex System for Heat Utilization and Reduction of Hazardous Air Emissions

    O. Kascheeva

    2012-01-01

    Full Text Available Investigations concern heat utilization and reduction of hazardous emissions occurring in residential buildings and accompanying operation of a great number of industrial enterprises in particular heat and power objects, and firstly, heat-generating units of small power located in densely populated residential areas without centralized heat supply.The investigation target is to reduce cost of heat produced by independent system of building heat supply, reduction of air pollution  due to hazardous gas emissions and reduction of heat pollution of the environment as a result of building ventilation system operation, ventilation of their internal and external sewerage network and higher reliability of their operation.The target is achieved because the device with complex system for heat utilization and reduction of hazardous air emissions has additionally an assembly tank for mixing flue gases, ventilation emissions and atmospheric air, heat pump. Evaporation zone of the pump is a condensator of the gas mixture and its condensate zone contains a heat supply line for a heat consumer. The line is equipped with assembling  and distributing collectors, pipeline connecting the heat supply line with the system of direct and return delivery water from a boiler house, a separator for division of liquid and gaseous mixture phases, neutralizing devices for separate reduction of concentrations of hazardous and odorous substances being released in gaseous and liquid portions of the mixture, a pipeline for periodic supply of air with higher concentration of hazardous and odorous substances in the boiler furnace. The supplied air is obtained as a result of its passing through gas filters at their regeneration when their exchange capacity is exhausted.

  5. On-line corrosion monitoring in geothermal district heating systems

    Richter, S.; Hilbert, Lisbeth Rischel; Thorarinsdottir, R.I.

    2006-01-01

    General corrosion rates in the geothermal district heating systems in Iceland are generally low, of the magnitude 1 lm/y. The reason is high pH (9.5), low-conductivity (200 lm/y) and negligible dissolved oxygen. The geothermal hot water is either used directly from source or to heat up cold ground...

  6. Expedient arrangement of newly constructed systems for centralized heat supply

    Zeigarnik, Yu. A.; Rotinov, A. G.

    2008-11-01

    It is shown that for newly constructed combined-cycle cogeneration plants and nuclear cogeneration plants, the optimum arrangement of the centralized heat supply system is the combination of a cogeneration plant and a district heat-supply station (a boiler house).

  7. Buying behaviour related to heating systems in Germany

    Decker, T.; Zapilko, M. (Straubing Center of Science, Straubing (Germany), Univ. of Applied Sciences Weibenstephan- Triesdorf), e-mail: t.decker@wz-straubing.de

    2010-07-01

    The decision for buying a heating system is a long-term one, as many different aspects have an influence on this choice which were analyzed in a Germany-wide, written survey. The respondents (only owners of a private house) has to answer questions about their attitude towards e.g. economic, convenience or ecological aspects related to heating systems and the respective combustibles. Using a multinomial logistic regression model the choice of the heating system is mainly explained by ecological attitudes and the estimation of different combustibles. (orig.)

  8. Energy source completion for geothermal district heating systems

    Geothermal district heating systems differs from the others mainly in the part of energy source completion and its connection to the heat distribution systems rather known problem. Even rather known problematic in the countries where geothermal energy is in wide application, new appearances of mistakes are always present due to the fact that necessary literature is difficult to be found. Essentials of the geothermal well completion and connection of geothermal source to the district heating distribution system are summarized in the paper and several examples of geothermal projects in flow are presented. (Author)

  9. Microwave Sinterator Freeform Additive Construction System (MS-FACS)

    Howe, Alan S.; Wilcox, Brian H.; Barmatz, Martin B.; Mercury, Michael B.; Siebert, Michael A.; Rieber, Richard R.

    2013-01-01

    The harmful properties of lunar dust, such as small size, glass composition, abnormal surface area, and coatings of imbedded nanophase iron, lead to a unique coupling of the dust with microwave radiation. This coupling can be exploited for rapid sintering of lunar soil for use as a construction material that can be formed to take on an infinite number of shapes and sizes. This work describes a system concept for building structures on the lunar surface using lunar regolith (soil). This system uses the ATHLETE (All-Terrain Hex- Limbed Extra-Terrestrial Explorer) mobility system as a positioning system with a microwave print head (similar to that of a smaller-scale 3D printer). A processing system delivers the lunar regolith to the microwave print head, where the microwave print head/chamber lays down a layer of melted regolith. An arm on the ATHLETE system positions the layer depending on the desired structure.

  10. Experimental analysis on performance of high temperature heat pump and desiccant wheel system

    Sheng, Ying; Zhang, Yufeng; Deng, Na;

    2013-01-01

    In order to solve the problem of high energy consumption for regeneration of desiccant wheel in the rotary desiccant system, high temperature heat pump and desiccant wheel (HTHP&DW) system and corresponding air conditioning unit is built and tested in the extensive thermal hygrometric environment....... When the mixture refrigerant BY-3 is involved in the air source heat pump, the supply air temperatures are in the range as expected except that when in the extreme hot environment (above 36°C), dehumidification capability are satisfied and the regeneration temperatures can satisfy the regeneration...... requirement of desiccant without additional heat. It is also found that outdoor air temperature, humidity ratio and regeneration air flow rate have great impact on the performance of heat pump based on the coefficient of performance (COP) evaluated. COP is not quite high, as the maximum value is 2.26 for heat...

  11. An active and selective heterogeneous catalytic system for Michael addition

    Hoda Keipour; Mohammad A. Khalilzadeh; Abolfazl Hosseini; Afsaneh Pilevar; Daryoush Zareyee

    2012-01-01

    Potassium fluoride doped natural zeolite was found to be an efficient and selective solid base catalyst for 1,4-Michael addition.The catalyst is easily prepared and the workup procedure simplified by simple filtration.All products were obtained in high yields as well as short reaction times.

  12. [The Bridgelok system for additional retention of bonded prostheses].

    Maroto García, J; Gutiérrez Molero, F; López Montero, M V

    1989-04-01

    The partial protesis with metal carving and cemented with composite resin is used frequently as a reversible method in order to substitute teeth, due to the light preparation necessary for the original teeth. Recently, a new system (Bridgelok) with pins has been proposed as safer for this kind of protesis. This paper studies if this new system originates a higher resistance compared to other system without pins. PMID:2699415

  13. Ash reduction system using electrically heated particulate matter filter

    Gonze, Eugene V [Pinckney, MI; Paratore, Jr., Michael J; He, Yongsheng [Sterling Heights, MI

    2011-08-16

    A control system for reducing ash comprises a temperature estimator module that estimates a temperature of an electrically heated particulate matter (PM) filter. A temperature and position estimator module estimates a position and temperature of an oxidation wave within the electrically heated PM filter. An ash reduction control module adjusts at least one of exhaust flow, fuel and oxygen levels in the electrically heated PM filter to adjust a position of the oxidation wave within the electrically heated PM filter based on the oxidation wave temperature and position.

  14. Contribution of domestic heating systems to smart grid control

    Tahersima, Fatemeh; Stoustrup, Jakob; Meybodi, Soroush Afkhami;

    2011-01-01

    is to deviate power consumption of the heat pump from its optimal value, in order to compensate power imbalances in the grid. Heating systems could be forced to consume energy, i.e. storing it in heat buffers when there is a power surplus in the grid; and be prevented from using power, in case of...... power shortage. We have investigated how much power imbalance could be compensated, provided that a certain, yet user adjustable, level of residents' thermal comfort is satisfied. It is shown that the large heat capacity of the concrete floor alleviates undesired temperature fluctuations. Therefore...

  15. Experimental Investigation on Decay Heat Removal System of CEFR

    2001-01-01

    The decay heat exists in a relative long time period after reactor shut down. The decay heat is removed by the decay heat removal system (DHRS).The manager of CEFR demanded that experiments should be carried out to make sure that natural circulation could be established under the conditions of < 1.0 percent of the normal power. Experiments are therefore performed under the heating power of 2, 3, 4, 6 and 8.5 kW respectively. The measured temperature in the hot plenum will be used to validate the computer codes. Moreover,

  16. Low exhaust temperature electrically heated particulate matter filter system

    Gonze, Eugene V.; Paratore, Jr., Michael J.; Bhatia, Garima

    2012-02-14

    A system includes a particulate matter (PM) filter, a sensor, a heating element, and a control module. The PM filter includes with an upstream end that receives exhaust gas, a downstream end and multiple zones. The sensor detects a temperature of the exhaust gas. The control module controls current to the heating element to convection heat one of the zones and initiate a regeneration process. The control module selectively increases current to the heating element relative to a reference regeneration current level when the temperature is less than a predetermined temperature.

  17. Dynamic performance of a novel solar photovoltaic/loop-heat-pipe heat pump system

    Highlights: • A transient model was developed to predict dynamic performance of new PV/LHP system. • The model accuracy was validated by experiment giving less than 9% in error. • The new system had basic and advanced performance coefficients of 5.51 and 8.71. • The new system had a COP 1.5–4 times that for conventional heat pump systems. • The new system had higher exergetic efficiency than PV and solar collector systems. - Abstract: Objective of the paper is to present an investigation into the dynamic performance of a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for potential use in space heating or hot water generation. The methods used include theoretical computer simulation, experimental verification, analysis and comparison. The fundamental equations governing the transient processes of solar transmission, heat transfer, fluid flow and photovoltaic (PV) power generation were appropriately integrated to address the energy balances occurring in different parts of the system, e.g., glazing cover, PV cells, fin sheet, loop heat pipe, heat pump cycle and water tank. A dedicated computer model was developed to resolve the above grouping equations and consequently predict the system’s dynamic performance. An experimental rig was constructed and operated under the real weather conditions for over one week in Shanghai to evaluate the system living performance, which was undertaken by measurement of various operational parameters, e.g., solar radiation, photovoltaic power generation, temperatures and heat pump compressor consumption. On the basis of the first- (energetic) and second- (exergetic) thermodynamic laws, an overall evaluation approach was proposed and applied to conduct both quantitative and qualitative analysis of the PV/LHP module’s efficiency, which involved use of the basic thermal performance coefficient (COPth) and the advanced performance coefficient (COPPV/T) of such a system. Moreover, a simple comparison

  18. Contracting at Lilienthal. Heating systems in the communal heat supply; Contracting in Lilienthal. Heiztechnik in der kommunalen Waermeversorgung

    Henze, Martin; Last, Dieter

    2009-07-01

    In the community of Lilienthal near Bremen, several communal buildings had to be modernized. A contracting model was chosen for the heating systems. New components of the heating system and control system were provided by an established producer of heating systems. (orig.)

  19. Green certificate system for heating - principal and practical challenges

    A certificate system with an obligation to buying is a very relevant instrument in energy policy in order to stimulate the implementation of new renewable energy sources. This solution is widely supported; it is being institutionalized in many countries, especially in Europe and in the electricity sector, and the heating sector is soon to follow. This report discusses the broad lines of a possible green certificate system for the heating sector in Norway and concludes that it is might well be linked with a similar system for the electricity sector. For Norway, an isolated certificate system for the electricity sector would not be cost-effective. This is because this system would emphasize relatively expensive renewable electric energy rather than utilizing the large potential for replacing the electric heating of buildings with much cheaper renewable heat

  20. IEA Annex 26: Advanced Supermarket Refrigeration/Heat Recovery Systems

    Baxter, VAN

    2003-05-19

    With increased concern about the impact of refrigerant leakage on global warming, a number of new supermarket refrigeration system configurations requiring significantly less refrigerant charge are being considered. In order to help promote the development of advanced systems and expand the knowledge base for energy-efficient supermarket technology, the International Energy Agency (IEA) established IEA Annex 26 (Advanced Supermarket Refrigeration/Heat Recovery Systems) under the ''IEA Implementing Agreement on Heat Pumping Technologies''. Annex 26 focuses on demonstrating and documenting the energy saving and environmental benefits of advanced systems design for food refrigeration and space heating and cooling for supermarkets. Advanced in this context means systems that use less energy, require less refrigerant and produce lower refrigerant emissions. Stated another way, the goal is to identify supermarket refrigeration and HVAC technology options that reduce the total equivalent warming impact (TEWI) of supermarkets by reducing both system energy use (increasing efficiency) and reducing total refrigerant charge. The Annex has five participating countries: Canada, Denmark, Sweden, the United Kingdom, and the United States. The working program of the Annex has involved analytical and experimental investigation of several candidate system design approaches to determine their potential to reduce refrigerant usage and energy consumption. Advanced refrigeration system types investigated include the following: distributed compressor systems--small parallel compressor racks are located in close proximity to the food display cases they serve thus significantly shortening the connecting refrigerant line lengths; secondary loop systems--one or more central chillers are used to refrigerate a secondary coolant (e.g. brine, ice slurry, or CO2) that is pumped to the food display cases on the sales floor; self-contained display cases--each food display case

  1. Influence green sand system by core sand additions

    N. Špirutová

    2012-01-01

    Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

  2. Effect of soluble additives, boric acid (H3BO3) and salt (NaCI), in pool boiling heat transfer

    The effects on pool boiling heat transfer of aqueous solutions of boric acid (H3BO3) and sodium chloride (NaCl) as working fluids have been studied. Borated and NaCl water were prepared by dissolving 0.5∼5% volume concentration of boric acid and NaCl in distilled-deionized water. The pool boiling tests were conducted using 1 x 1 cm2 flat heaters at 1 atm. The critical heat flux (CHF) dramatically increased compared to boiling pure water. At the end of boiling tests it was observed that particles of boric acid and NaCl had deposited and formed a coating on the heater surface. The CHF enhancement and surface modification during boiling tests were very similar to those obtained from boiling with nanofluids. Additional experiments were carried out to investigate the reliability of the additives deposition in pure water. The boric acid and NaCl coatings disappeared after repeated boiling tests on the same surface due to the soluble nature of the coatings, thus CHF enhancement no longer existed. These results demonstrate that not only insoluble nanoparticles but also soluble salts can be deposited during boiling process and the deposited layer is solely responsible for significant CHF enhancement

  3. Segmented heat exchanger

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  4. Horizontal Heat Exchanger Design and Analysis for Passive Heat Removal Systems

    Vierow, Karen

    2005-08-29

    This report describes a three-year project to investigate the major factors of horizontal heat exchanger performance in passive containment heat removal from a light water reactor following a design basis accident LOCA (Loss of Coolant Accident). The heat exchanger studied in this work may be used in advanced and innovative reactors, in which passive heat removal systems are adopted to improve safety and reliability The application of horizontal tube-bundle condensers to passive containment heat removal is new. In order to show the feasibility of horizontal heat exchangers for passive containment cooling, the following aspects were investigated: 1. the condensation heat transfer characteristics when the incoming fluid contains noncondensable gases 2. the effectiveness of condensate draining in the horizontal orientation 3. the conditions that may lead to unstable condenser operation or highly degraded performance 4. multi-tube behavior with the associated secondary-side effects This project consisted of two experimental investigations and analytical model development for incorporation into industry safety codes such as TRAC and RELAP. A physical understanding of the flow and heat transfer phenomena was obtained and reflected in the analysis models. Two gradute students (one funded by the program) and seven undergraduate students obtained research experience as a part of this program.

  5. Solar heating and cooling system design and development

    1979-01-01

    The design and development of marketable solar heating and cooling systems for single family and commercial applications is described. The delivery, installation, and monitoring of the prototype systems are discussed. Seven operational test sites are discussed in terms of system performance. Problems encountered with equipment and installation were usually due to lack of skills required for solar system installation.

  6. Design studies of supplemental-heating systems. Quarterly report No. 2

    The first objective is to summarize and evaluate the data base for Tokamak heating systems, in order to understand thoroughly the technology, cost and risk implications associated with the selection of any particular heating technique. A preliminary selection of optimized RF and neutral beam systems will be made for a near-term device (TFTR), based on existing data. This will provide a technical and cost base for the second phase where concept and design selection will be performed for an advanced reactor system. In addition, the analysis procedure will be carefully documented, together with a program plan for the development of each of the systems and a detailed cost estimate

  7. 3D Additive Construction with Regolith for Surface Systems Project

    National Aeronautics and Space Administration — Recent work in the NASA Kennedy Space Center (KSC) Surface Systems Office (NE-S) Swamp Works and at the University of Southern California (USC) under two...

  8. Flexibility of a combined heat and power system with thermal energy storage for district heating

    Highlights: ► A generic model for flexibility assessment of thermal systems is proposed. ► The model is applied to a combined heat and power system with thermal energy storage. ► A centrally located storage offers more flexibility compared to individual units. ► Increasing the flexibility requires both a more powerful CHP and a larger buffer. - Abstract: The trend towards an increased importance of distributed (renewable) energy resources characterized by intermittent operation redefines the energy landscape. The stochastic nature of the energy systems on the supply side requires increased flexibility at the demand side. We present a model that determines the theoretical maximum of flexibility of a combined heat and power system coupled to a thermal energy storage solution that can be either centralized or decentralized. Conventional central heating, to meet the heat demand at peak moments, is also available. The implications of both storage concepts are evaluated in a reference district. The amount of flexibility created in the district heating system is determined by the approach of the system through delayed or forced operation mode. It is found that the distinction between the implementation of the thermal energy storage as a central unit or as a collection of local units, has a dramatic effect on the amount of available flexibility

  9. Passive ventilation systems with heat recovery and night cooling

    Hviid, Christian Anker; Svendsen, Svend

    University of Denmark. Through building integration in high performance offices the system is optimized to incorporate multiple functions like heating, cooling and ventilation, thus saving the expenses of separate cooling and heating systems. The simulation results are derived using the state......In building design the requirements for energy consumption for ventilation, heating and cooling and the requirements for increasingly better indoor climate are two opposing factors. This paper presents the schematic layout and simulation results of an innovative multifunc-tional ventilation concept...... with little energy consumption and with satisfying indoor climate. The concept is based on using passive measures like stack and wind driven ventilation, effective night cooling and low pressure loss heat recovery using two fluid coupled water-to-air heat exchangers developed at the Technical...

  10. On the control of heating systems in the UK

    Liao, Z.; Swainson, M. [BRE, Watford (United Kingdom); Dexter, A.L. [University of Oxford (United Kingdom). Dept. of Engineering Science

    2005-03-01

    This paper reviews current heating system control practice in the UK through surveys, computer simulation and experimental studies. It is evident from the survey results that both boiler and heat emitter controls in the UK are generally poor. Computer simulation of a heating system demonstrated that the use of poorly commissioned boiler controls and the use of thermostatic valves with limited flow control leads to buildings not maintaining the desired internal temperatures. This results in occupant discomfort when under-heating occurs and excess fuel consumption when over-heating occurs. Finally, an experimental study demonstrated that a newly developed boiler control algorithm can offer significant energy savings by controlling the boiler more appropriately and reducing the effect of poor thermostatic radiator valve use. (author)

  11. Combined solar heat and power system with a latent heat storage - system simulations for an economic assessment

    Zipf, Verena; Neuhäuser, Anton

    2016-05-01

    Decentralized solar combined heat and power (CHP) systems can be economically feasible, especially when they have a thermal storage. In such systems, heat provided by solar thermal collectors is used to generate electricity and useful heat for e.g. industrial processes. For the supply of energy in times without solar irradiation, a thermal storage can be integrated. In this work, the performance of a solar CHP system using an active latent heat storage with a screw heat exchanger is investigated. Annual yield calculations are conducted in order to calculate annual energy gains and, based on them; economic assumptions are used to calculated economic numbers in order to assess the system performance. The energy savings of a solar system, compared to a system with a fossil fuel supply, are calculated. Then the net present value and the dynamic payback are calculated with these savings, the initial investment costs and the operational costs. By interpretation and comparison of these economic numbers, an optimum system design in terms of solar field size and storage size was determined. It has been shown that the utilization of such systems can be economical in remote areas without gas and grid connection. Optimal storage design parameters in terms of the temperature differences in the heat exchanger and the storage capacity have been determined which can further increase the net present value of such system.

  12. Simulation of a solar assisted combined heat pump – Organic rankine cycle system

    Highlights: • Addition of an ORC to a solar thermal and ground source heat pump system. • Reverse operation of the scroll compressor in ORC mode. • Annual simulations for application in a single-family house at three locations. • By introducing the ORC the net electricity demand is reduced by 1–9%. • Over the lifetime of the system savings can cover additional investments. - Abstract: A novel solar thermal and ground source heat pump system that harnesses the excess heat of the collectors during summer by an Organic Rankine Cycle (ORC) is simulated. For the ORC the heat pump process is reversed. In this case the scroll compressor of the heat pump runs as a scroll expander and the working fluid is condensed in the ground heat exchanger. Compared to a conventional solar thermal system the only additional investments for the combined system are a pump, valves and upgraded controls. The goal of the study is to simulate and optimize such a system. A brief overview of the applied models and the evolutionary algorithm for the optimization is given. A system with 12 m2 of flat plate collectors installed in a single family house is simulated for the locations Ankara, Denver and Bochum. The ORC benefits add up to 20–140 kW h/a, which reduces the net electricity demand of the system by 1–9%. Overall 180–520 € are saved over a period of 20 years, which can be enough to cover the additional investments

  13. Design of Heat Integrated Low Temperature Distillation Systems

    Sonia Farrokhpanah

    2009-01-01

    This work addresses the challenges in design of heat integrated low-temperatureseparation processes. A novel, systematic and robust methodology is developed,which contributes to the design practice of heat-integrated separation sequenceand the refrigeration system in the context of low-temperature separationprocesses. Moreover, the methodology exploits the interactions between theseparation and refrigeration systems systematically in an integrated designcontext.The synthesis and optimisation ...

  14. Decentralized Architecture for Load Balancing in District Heating Systems

    Rodriguez, German Darío Rivas

    2011-01-01

    Context. In forthcoming years, sustainability will lead the development of society. Implementation of innovative systems to make the world more sustainable is becoming one of the key points for science. Load balancing strategies aim to reduce economic and ecological cost of the heat production in district heating systems. Development of a decentralized solution lies in the objective of making the load balancing more accessible and attractive for the companies in charge of providing district-h...

  15. Exact non-additive kinetic potentials in realistic chemical systems.

    de Silva, Piotr; Wesolowski, Tomasz A

    2012-09-01

    In methods based on frozen-density embedding theory or subsystem formulation of density functional theory, the non-additive kinetic potential (v(t)(nad)(r)) needs to be approximated. Since v(t)(nad)(r) is defined as a bifunctional, the common strategies rely on approximating v(t)(nad)[ρ(A),ρ(B)](r). In this work, the exact potentials (not bifunctionals) are constructed for chemically relevant pairs of electron densities (ρ(A) and ρ(B)) representing: dissociating molecules, two parts of a molecule linked by a covalent bond, or valence and core electrons. The method used is applicable only for particular case, where ρ(A) is a one-electron or spin-compensated two-electron density, for which the analytic relation between the density and potential exists. The sum ρ(A) + ρ(B) is, however, not limited to such restrictions. Kohn-Sham molecular densities are used for this purpose. The constructed potentials are analyzed to identify the properties which must be taken into account when constructing approximations to the corresponding bifunctional. It is comprehensively shown that the full von Weizsäcker component is indispensable in order to approximate adequately the non-additive kinetic potential for such pairs of densities. PMID:22957558

  16. Buildings as solar heat stores. Heating system control and room activation; Das Gebaeude als Solarspeicher. Heizungsregelung mit Raumaktivierung

    Heckmeier, J. [Orange Energy, Schweitenkirchen (Germany); SHK-Betrieb Josef Heckmeier Haustechnik (Germany)

    2007-08-15

    When solar heating systems are used as auxiliary heating systems, there is often a gap between heat production and heat demand, especially with large collector surfaces. An intelligent control concept (innovative room bus system) is presented which narrows this gap and makes a significant contribution to energy conservation and CO2 reduction. The newly developed system also offers high comfort and user-friendliness. (orig.)

  17. The right technology for energy measuring in district heating systems

    Danfoss recommends ultrasonic flow metering as an efficient way to eliminate the threat of magnetite to electromagnetic flowmeters in district heating systems. Considering the enormous amount of money passing through any district heating system, the choice of metering technology is crucial to profitability. Even minor metering inaccuracies will soon burst budgets. This is why Danfoss after decades of experience in the industry strongly recommends the use of ultrasonic heat meters in all district heating applications from production plant to end user. The paramount benefit of the ultrasonic measurement technology is the certainty of always getting accurate results, thanks to the facts that: 1) The heat meters do not depend on conductivity. 2) Magnetite layers in the measuring pipe cannot influence the measurement. Avoiding these two main dangers to measurement accuracy in any district heating system makes ultrasonic heat metering unsurpassed. And the view is strongly confirmed by the fact that more and more authorities in Europe are considering to prolong the period for recalibration from 5 years up to 8-10 years in systems equipped with this technology. The paper deals with the advantages of this technology. (Authors)

  18. Heat Exchanger System Piping Design for a Tube Rupture Event

    Wakim, Fadi Antoine; Kavcar, Pinar Cakir; Samad, Mustafa

    2012-01-01

    ABSTRACT: Tube-rupture events in shell and tube heat exchangers can result in significantly high surge pressures. Steady state and dynamic methods can be used to assess the impacts of these events on heat exchanger system piping networks. This paper presents the findings of a set of dynamic surge simulations on the impacts of tube-rupture events in a Propane-Feed Gas Heat Exchanger System. Once adjacent piping design is considered, the Joukowsky formulation-based method is not always appropri...

  19. Laboratory research on combined cooling, heating and power (CCHP) systems

    Fu, L.; Zhao, X.L.; Zhang, S.G.; Jiang, Y.; Li, H.; Yang, W.W. [Department of Building Science, School of Architecture, Tsinghua University, Beijing (China)

    2009-04-15

    Combined cooling, heating and power (CCHP) systems offer the potential for a significant increase in fuel use efficiency by generating electricity onsite and recycling the exhaust gas for heating, cooling, or dehumidifying. A challenge for CCHP system is the efficient integration of distributed generation (DG) equipment with thermally-activated (TA) technologies. The China Ministry of Science and Technology and Tsinghua University launched the 863 Hi-Tech Program in 2007 to focus on laboratory and demonstration research to study the critical issues of CCHP systems, advance the technology and accelerate its application. The research performed at the Building Energy Research Center (BERC) Laboratory focuses on assessing the operational performance and energy efficiency of the integration of current DG and TA technologies; developing and verifying mathematical models of the individual devices and all the systems. The test laboratory is a flexible test-bed for the configuration of DG (presently a 70-kW natural gas-fired internal combustion engine (ICE) with various heat recovery units, such as an flue gas-to-water heat recovery unit (FWRU), a jacket water heat recovery unit (JRU), liquid desiccant dehumidification systems (LDS), an exhaust-gas-driven double-effect absorption heat pump (EDAHP), and a condensation heat recovery unit (CRU)). In the winter, the exhaust gas from the ICE is used in the FWRU or used to drive the EDAHP directly, and the exhaust gas from the EDAHP is used in the CRU. The water flows from the CRU can be directed to the evaporator side of the EDAHP as the low-grade heat source. The water flows from the condensation side of the EDAHP, in conjunction with the jacket water flows from the JRU, is used for heating. In the summer, the exhaust gas from the ICE is used to drive the EDAHP for cooling directly, the exhaust gas from the EDAHP is bypassed to the exit via automated damper controls. The waste heat of the jacket water is used to drive the

  20. Impact of Correlated Noises on Additive Dynamical Systems

    Chujin Li

    2014-01-01

    Full Text Available Impact of correlated noises on dynamical systems is investigated by considering Fokker-Planck type equations under the fractional white noise measure, which correspond to stochastic differential equations driven by fractional Brownian motions with the Hurst parameter H>1/2. Firstly, by constructing the fractional white noise framework, one small noise limit theorem is proved, which provides an estimate for the deviation of random solution orbits from the corresponding deterministic orbits. Secondly, numerical experiments are conducted to examine the probability density evolutions of two special dynamical systems, as the Hurst parameter H varies. Certain behaviors of the probability density functions are observed.

  1. Fault isolability conditions for linear systems with additive faults

    Niemann, Hans Henrik; Stoustrup, Jakob

    2006-01-01

    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...... can occur simultaneously, whereas faults belonging to different fault sets appear disjoint in time. The proposed fault detection and isolation (FDI) scheme consists of three steps. A fault detection (FD) step is followed by a fault set isolation (FSI) step. Here the fault set is isolated wherein the...... faults have occurred. The last step is a fault isolation (FI) of the faults occurring in a specific fault set, i.e. equivalent with the standard FI step....

  2. Application of waste heat powered absorption refrigeration system to the LNG recovery process

    Kalinowski, Paul; Hwang, Yunho; Radermacher, Reinhard [Center for Environmental Energy Engineering, Department of Mechanical Engineering, University of Maryland, College Park, MD 20742 (United States); Al Hashimi, Saleh; Rodgers, Peter [The Petroleum Institute, Abu Dhabi (United Arab Emirates)

    2009-06-15

    The recovery process of the liquefied natural gas requires low temperature cooling, which is typically provided by the vapor compression refrigeration systems. The usage of an absorption refrigeration system powered by waste heat from the electric power generating gas turbine could provide the necessary cooling at reduced overall energy consumption. In this study, a potential replacement of propane chillers with absorption refrigeration systems was theoretically analyzed. From the analysis, it was found that recovering waste heat from a 9 megawatts (MW) electricity generation process could provide 5.2 MW waste heat produced additional cooling to the LNG plant and save 1.9 MW of electricity consumption. Application of the integrated cooling, heating, and power is an excellent energy saving option for the oil and gas industry. (author)

  3. Optimization of Serial Combined System of Ground-Coupled Heat Pump and Solar Collector

    ZHAO Jun; CHEN Yan; LU Suzhen; CUI Junkui

    2009-01-01

    A mathematical optimization model was set up for a ground-solar combined system based on in-situ experimental results,in which the solar collector was combined serially with a ground-coupled heat pump(GCHP).The universal optimal equations were solved by the constrained variable metric method considering both the performance and economics.Then the model was applied to a specific case concerning an actual solar assisted GCHP system for space heating.The results indicated a system coefficient of performance(COP)of 3.9 for the optimal method under the seriaI heating mode,and 3.2 for the conventional one.In addition,the optimum solution also showed advantages in energy and cost saving.1eading to a 16.7%improvement in the heat pump performance at 17.2%less energy consumption and 11.8%lower annual cost,respectively.

  4. Technoeconomic analysis of a biomass based district heating system

    This paper discussed a proposed biomass-based district heating system to be built for the Pictou Landing First Nation Community in Nova Scotia. The community centre consists of 6 buildings and a connecting arcade. The methodology used to size and design heating, ventilating and air conditioning (HVAC) systems, as well as biomass district energy systems (DES) were discussed. Annual energy requirements and biomass fuel consumption predictions were presented, along with cost estimates. A comparative assessment of the system with that of a conventional oil fired system was also conducted. It was suggested that the design and analysis methodology could be used for any similar application. The buildings were modelled and simulated using the Hourly Analysis Program (HAP), a detailed 2-in-1 software program which can be used both for HVAC system sizing and building energy consumption estimation. A techno-economics analysis was conducted to justify the viability of the biomass combustion system. Heating load calculations were performed assuming that the thermostat was set constantly at 22 degrees C. Community centre space heating loads due to individual envelope components for 3 different scenarios were summarized, as the design architecture for the buildings was not yet finalized. It was suggested that efforts should be made to ensure air-tightness and insulation levels of the interior arcade glass wall. A hydronic distribution system with baseboard space heating units was selected, comprising of a woodchip boiler, hot water distribution system, convective heating units and control systems. The community has its own logging operation which will provide the wood fuel required by the proposed system. An outline of the annual allowable harvest covered by the Pictou Landing Forestry Management Plan was presented, with details of proposed wood-chippers for the creation of biomass. It was concluded that the woodchip combustion system is economically preferable to the

  5. Optimizing the Heat Exchanger Network of a Steam Reforming System

    Nielsen, Mads Pagh; Korsgaard, Anders Risum; Kær, Søren Knudsen

    2004-01-01

    steam reforming reaction and steam must be generated. The dependence of the temperature profiles on conversion in shift reactors for gas purification is also significant. The optimum heat integration in the system is thus imperative in order to minimize the need for hot and cold utilities. A rigorous 1D......Proton Exchange Membrane (PEM) based combined heat and power production systems are highly integrated energy systems. They may include a hydrogen production system and fuel cell stacks along with post combustion units optionally coupled with gas turbines. The considered system is based on a natural...... gas steam reformer along with gas purification reactors to generate clean hydrogen suited for a PEM stack. The temperatures in the various reactors in the fuel processing system vary from around 1000°C to the stack temperature at 80°C. Furthermore, external heating must be supplied to the endothermic...

  6. Waste heat utilization in an anaerobic digestion system

    Boissevain, Brett

    Anaerobic digestion has great potential as an energy source. Not only does it provide an effective method for waste mitigation, but it has the potential to generate significant quantities of fuel and electricity. In order to ensure efficient digestion and biomass utilization, however, the system must be continuously maintained at elevated temperatures. It is technically feasible to supplement such a system with outside energy, but it is more cost effective to heat the system using only the produced biogas. While there is considerable literature covering the theory of anaerobic digestion, there are very few practical studies to show how heat utilization affects system operation. This study considers the effect of major design variables (i.e. heat exchanger efficiencies and biogas conditioning) on promoting a completely self-sustaining digestion system. The thesis considers a real world system and analyzes how it can be improved to avoid the need of an external energy source.

  7. Time-delay models of heat transfer systems

    The paper deals with a new approach to modeling the heat transfer phenomena by means of differential equations with delays. The infinite order dynamics of thermal processes by suitable combinations of capacitance and delay elements is presented. An identification of transfer function of heat exchangers is presented. In the mathematical treatment of heat transfer systems, it is usually quite advantageous to deal in the frequency domain rather than the time. In such cases, the response of the system to sinusoidal inputs over a band of frequencies must be known. Identification is based on the least square method, which is based on minimization of the weighted sum of the squares of the errors between the absolute magnitudes of the frequency characteristic real object and the frequency characteristic of time-delay model of heat transfer system, which is proposed in this paper. (author)

  8. Inhibitor analysis for a solar heating and cooling system

    Tabony, J. H.

    1977-01-01

    A study of potential corrosion inhibitors for the NASA solar heating and cooling system which uses aluminum solar panels is provided. Research consisted of testing using a dynamic corrosion system, along with an economic analysis of proposed corrosion inhibitors. Very good progress was made in finding a suitable inhibitor for the system.

  9. Space Heating Load Estimation Procedure for CHP Systems sizing

    Vocale, P.; Pagliarini, G.; Rainieri, S.

    2015-11-01

    Due to its environmental and energy benefits, the Combined Heat and Power (CHP) represents certainly an important measure to improve energy efficiency of buildings. Since the energy performance of the CHP systems strongly depends on the fraction of the useful cogenerated heat (i.e. the cogenerated heat that is actually used to meet building thermal demand), in building applications of CHP, it is necessary to know the space heating and cooling loads profile to optimise the system efficiency. When the heating load profile is unknown or difficult to calculate with a sufficient accuracy, as may occur for existing buildings, it can be estimated from the cumulated energy uses by adopting the loads estimation procedure (h-LEP). With the aim to evaluate the useful fraction of the cogenerated heat for different operating conditions in terms of buildings characteristics, weather data and system capacity, the h-LEP is here implemented with a single climate variable: the hourly average dry- bulb temperature. The proposed procedure have been validated resorting to the TRNSYS simulation tool. The results, obtained by considering a building for hospital use, reveal that the useful fraction of the cogenerated heat can be estimated with an average accuracy of ± 3%, within the range of operative conditions considered in the present study.

  10. Performance of active solar space-heating systems, 1980-1981 heating season

    Welch, K.; Kendall, P.; Pakkala, P.; Cramer, M.

    1981-01-01

    Data are provided on 32 solar heating sites in the National Solar Data Network (NSDN). Of these, comprehensive data are included for 14 sites which cover a range of system types and solar applications. A brief description of the remaining sites is included along with system problems experienced which prevented comprehensive seasonal analyses. Tables and discussions of individual site parameters such as collector areas, storage tank sizes, manufacturers, building dimensions, etc. are provided. Tables and summaries of 1980-1981 heating season data are also provided. Analysis results are presented in graphic form to highlight key summary information. Performance indices are graphed for two major groups of collectors - liquid and air. Comparative results of multiple NSDN systems' operation for the 1980-1981 heating season are summarized with discussions of specific cases and conclusions which may be drawn from the data. (LEW)

  11. Dynamic behavior of district heating systems. 1. Report

    In this study a comprehensive model simulating the dynamic behavior of an entire district heating system has been developed. The model consists of four partial models, namely a model of the hydraulic behavior of a heat distribution network, another model of the thermal behavior of this network, a model of the heat generation plants and one of the heat consumers connected to the system. For the hydraulic simulation of the distribution network, a classical steady state approach has proved to be sufficient. The evolution of the temperatures in the network is given by the equation of transport. A numerical resolution scheme, which is adapted to the special case of a heat distribution network was developed for this equation. The model developed for the heating plant is simple but it is sufficiently detailed to determine the operation of its elements. A more complex model would take much more calculation time, but with such a simple model, it is possible to include it in the global model of the entire system. Each heat consumer is represented by a simple one cell model. The difficulty in such an approach is to determine the characteristics of each building in a simple manner. A classification, which allows to find the essential parameters from few and easily available data, has been defined. This model is not sufficiently accurate to calculate the thermal behavior of one specific building but it allows to determine the average dynamic evolution of the heat demand for a set of buildings with a good precision.The developed models have been programmed on a personal computer and the entire district heating network of the city of Lausanne has been simulated with this calculation code. Measurements have been taken on this network and the comparison with calculated results has allowed to calibrate the model. The comparison of measurements and calculations shows, that each part of the system is simulated realistically by the proposed model. (author) figs., tabs., refs

  12. Development of hybrid solar-assisted cooling/heating system

    Huang, B.J.

    2010-08-01

    A solar-assisted ejector cooling/heating system (SACH) was developed in this study. The SACH combines a pump-less ejector cooling system (ECS) with an inverter-type heat pump (R22) and is able to provide a stable capacity for space cooling. The ECS is driven by solar heat and is used to cool the condenser of the R22 heat pump to increase its COP and reduce the energy consumption of the compressor by regulating the rotational speed of the compressor through a control system. In a complete SACH system test run at outdoor temperature 35 °C, indoor temperature 25 °C and compressor speed 20-80 Hz, and the ECS operating at generator temperature 90 °C and condensing temperature 37 °C, the corresponding condensing temperature of the heat pump in the SACH is 24.5-42 °C, cooling capacity 1.02-2.44 kW, input power 0.20-0.98 kW, and cooling COPc 5.11-2.50. This indicates that the use of ECS in SACH can effectively reduce the condensing temperature of the heat pump by 12.6-7.3 °C and reduce the power consumption by 81.2-34.5%. The SACH can also supply heat from the heat pump. At ambient temperature from 5 °C to 35 °C, the heating COPh is in the range 2.0-3.3. © 2010 Elsevier Ltd. All rights reserved.

  13. Additive Manufacturing of 17-4 PH Stainless Steel: Post-processing Heat Treatment to Achieve Uniform Reproducible Microstructure

    Cheruvathur, Sudha; Lass, Eric A.; Campbell, Carelyn E.

    2016-03-01

    17-4 precipitation hardenable (PH) stainless steel is a useful material when a combination of high strength and good corrosion resistance up to about 315°C is required. In the wrought form, this steel has a fully martensitic structure that can be strengthened by precipitation of fine Cu-rich face-centered cubic phase upon aging. When fabricated via additive manufacturing (AM), specifically laser powder-bed fusion, 17-4 PH steel exhibits a dendritic structure containing a substantial fraction of nearly 50% of retained austenite along with body centered cubic/martensite and fine niobium carbides preferentially aligned along interdendritic boundaries. The effect of post-build thermal processing on the material microstructure is studied in comparison to that of conventionally produced wrought 17-4 PH with the intention of creating a more uniform, fully martensitic microstructure. The recommended stress relief heat treatment currently employed in industry for post-processing of AM 17-4 PH steel is found to have little effect on the as-built dendritic microstructure. It is found that, by implementing the recommended homogenization heat treatment regimen of Aerospace Materials Specification 5355 for CB7Cu-1, a casting alloy analog to 17-4 PH, the dendritic solidification structure is eliminated, resulting in a microstructure containing about 90% martensite with 10% retained austenite.

  14. Influence of tribomechanical micronization and hydrocolloids addition on enthalpy and apparent specific heat of whey protein model solutions

    Zoran Herceg

    2002-01-01

    Full Text Available Knowledge of thermophysical properties, especially the phase transitions temperature, specific heat and enthalpy, are essential in defining the freezing process parameters as well as storage conditions of frozen food. In this work thermophysical properties of 10% model solutions prepared with 60% whey protein concentrate (WPC with various hydrocolloids addition (HVEP, YO-EH, YO-L i YO-M were investigated. Powdered whey protein concentrate was treated in equipment for tribomechanical micronization and activation at 40000 rpm (Patent: PCT/1B99/00757 just before model solutions preparation. Particle size analysis was performed using Frich –laser particle sizer “analysette 22”. The phase transition temperatures were determined by differential thermal analysis (DTA, while specific heat and enthalpy were calculated according to several mathematical equations. The results have shown that, due to tribomechanical treatment, certain changes in thermophysical and energetic properties of materials occurred. Tribomechanical treatment affects changes in granulometrical composition of WPC which result in higher abilities of reactions with hydrocolloids in model solutions and significant changes in thermophysical properties of the mentioned models.

  15. Parametric Integral Equations Systems Method In Solving Unsteady Heat Transfer Problems For Laser Heated Materials

    Sawicki Dominik

    2015-09-01

    Full Text Available One of the most popular applications of high power lasers is heating of the surface layer of a material, in order to change its properties. Numerical methods allow an easy and fast way to simulate the heating process inside of the material. The most popular numerical methods FEM and BEM, used to simulate this kind of processes have one fundamental defect, which is the necessity of discretization of the boundary or the domain. An alternative to avoid the mentioned problem are parametric integral equations systems (PIES, which do not require classical discretization of the boundary and the domain while being numerically solved. PIES method was previously used with success to solve steady-state problems, as well as transient heat transfer problems. The purpose of this paper is to test the efficacy of the PIES method with time discretization in solving problem of laser heating of a material, with different pulse shape approximation functions.

  16. Exergy analysis of gas turbine trigeneration system for combined production of power heat and refrigeration

    Khaliq, Abdul [Department of Mechanical Engineering, Faculty of Engineering and Technology, Jamia Millia Islamia, New Delhi 110025 (India)

    2009-05-15

    A conceptual trigeneration system is proposed based on the conventional gas turbine cycle for the high temperature heat addition while adopting the heat recovery steam generator for process heat and vapor absorption refrigeration for the cold production. Combined first and second law approach is applied and computational analysis is performed to investigate the effects of overall pressure ratio, turbine inlet temperature, pressure drop in combustor and heat recovery steam generator, and evaporator temperature on the exergy destruction in each component, first law efficiency, electrical to thermal energy ratio, and second law efficiency of the system. Thermodynamic analysis indicates that exergy destruction in combustion chamber and HRSG is significantly affected by the pressure ratio and turbine inlet temperature, and not at all affected by pressure drop and evaporator temperature. The process heat pressure and evaporator temperature causes significant exergy destruction in various components of vapor absorption refrigeration cycle and HRSG. It also indicates that maximum exergy is destroyed during the combustion and steam generation process; which represents over 80% of the total exergy destruction in the overall system. The first law efficiency, electrical to thermal energy ratio and second law efficiency of the trigeneration, cogeneration, and gas turbine cycle significantly varies with the change in overall pressure ratio and turbine inlet temperature, but the change in pressure drop, process heat pressure, and evaporator temperature shows small variations in these parameters. Decision makers should find the methodology contained in this paper useful in the comparison and selection of advanced heat recovery systems. (author)

  17. Ground-source heat pump systems in Norway

    The Norwegian ground source heat pump (GSHP) market is reviewed. Boreholes in bedrock are of growing interest for residential systems and of growing interest for larger systems with thermal recharging or thermal energy storage. Ground water is limited to areas where the water has acceptable purity. Challenges and important boundary conditions include 1) high quality GSHP system requires engineering expertise, 2) new building codes and EU directive 'energy performance of buildings.'(2006), and 3) hydronic floor heating systems in 50 percent of new residences (author) (ml)

  18. Maximum-power-point tracking control of solar heating system

    Huang, Bin-Juine

    2012-11-01

    The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

  19. Heat recovery from wastewater systems; Waermerueckgewinnung aus Abwassersystemen

    Wanner, O.

    2004-07-01

    Wastewater contains large amounts of heat energy which can be recovered by means of a heat pump and a heat exchanger installed in the sewer system. Practical problems, which may arise and have been investigated in this research project, are the reduction of the heat transfer efficiency due to heat exchanger fouling and the reduction of the nitrification capacity of downstream wastewater treatment plants due to lower wastewater temperatures. A mathematical model was developed by which the decrease of the wastewater temperature in the treatment plant influent can be determined as a function of the amount of heat energy gathered from the wastewater in the sewer system. By this model the variation in time and space of the wastewater temperature in a sewer pipe is calculated for given hydraulics, geometry and environmental conditions. By analysis of data from a large wastewater treatment plant and simulations with a calibrated model, the effect of lowered influent temperatures on nitrification safety, total nitrogen removal efficiency and ammonium effluent concentrations could be quantified. A procedure is suggested by which the reserve nitrification capacity of an existing treatment plant and the increase of the ammonium effluent concentration resulting from a permanent decrease of the wastewater influent temperature can be estimated. By experiments with a pilot scale heat exchanger in a small wastewater channel, the significance of parameters known to have an effect on fouling was investigated and measures to reduce fouling were tested. The measures tested included controlled variation of the wastewater flow velocity (flushing), coatings and finish of the heat exchanger surface and obstacles mounted on the surface. The best results were obtained by regular short term increases of the flow velocity. By this measure, the efficiency of the fouled heat exchanger, which on the average was 60% of the efficiency of the clean heat exchanger, could repeatedly be raised to an

  20. Simulation on Cooling System of Automotive Waste Heat Thermoelectric Generator

    Xiaohong Yuan; Sufen Yuan; Changsheng Chen; Yadong Deng

    2013-01-01

    The cooling system of automobile waste heat Thermoelectric Generator (TEG) is researched in the study. Integrated model of cooling system and vehicle is built based on GT-Cool, analysis of the different cooling ways shows that when using independent cooling system, the ratio between power consumption and output is high and system performance is poor; By using integrated cooling system, the expectation of keep constant engine warm up time and synchronous change of water temperature between dif...

  1. Heat-pump-centered integrated community energy systems. Final report

    1979-11-01

    A Heat Pump Centered-Integrated Community Energy System (HP-ICES) concept was explored and developed that is based on use of privately owned ice-making heat pumps in each building or complex within a community. These heat pumps will provide all of the space heating, space cooling and domestic hot water needs. All of the community input energy required is provided by electrical power, thereby eliminating a community's dependence on gas or oil supplies. The heat pumps will operate in both air and water source modes, deriving performance advantages of both. The possible forms of an HP-ICES system, the technical and economic limitations, environmental impacts and other factors are discussed from a general viewpoint. The concept is applied to a specific planned community and its performance and economic features are examined in detail. It is concluded that the HP-ICES concept is technically viable, but that its economic desirability as compared with conventional heat pump systems is hampered by much higher initial costs, and that the economic feasibility of HP-ICES systems will depend on future fuel source costs and supply and on electric power rates. (LCL)

  2. Investigation of evacuated tube heated by solar trough concentrating system

    Two types of solar evacuated tube have been used to measure their heating efficiency and temperature with fluids of water and N2 respectively with a parabolic trough concentrator. Experiments demonstrate that both evacuated tubes present a good heat transfer with the fluid of water, the heating efficiency is about 70-80%, and the water is easy to boil when liquid rate is less than 0.0046 kg/s. However, the efficiency of solar concentrating system with evacuated tube for heating N2 gas is less than 40% when the temperature of N2 gas reaches 320-460 deg. C. A model for evacuated tube heated by solar trough concentrating system has been built in order to further analyze the characteristics of fluid which flow evacuated tube. It is found that the model agrees with the experiments to within 5.2% accuracy. The characteristics of fluid via evacuated tube heated by solar concentrated system are analyzed under the varying conditions of solar radiation and trough aperture area. This study supports research work on using a solar trough concentrating system to perform ammonia thermo-chemical energy storage for 24 h power generation. The current research work also has application to solar refrigeration

  3. Regional energy system optimization - Potential for a regional heat market

    Energy supply companies and industrial plants are likely to face new situations due to, for example, the introduction of new energy legislation, increased fuel prices and increased environmental awareness. These new prerequisites provide companies with new challenges but also new possibilities from which to benefit. Increased energy efficiency within companies and increased cooperation between different operators are two alternatives to meet the new conditions. A region characterized by a high density of energy-intensive processes is used in this study to find the economic potential of connecting three industrial plants and four energy companies, within three local district heating systems, to a regional heat market, in which different operators provide heat to a joint district heating grid. Also, different investment alternatives are studied. The results show that the economical potential for a heat market amounts to between 5 and 26 million EUR/year with payback times ranging from two to eleven years. However, the investment costs and the net benefit for the total system need to be allotted to the different operators, as they benefit economically to different extents from the introduction of a heat market. It is also shown that the emissions of CO2 from the joint system would decrease compared to separate operation of the systems. However, the valuation of CO2 emissions from electricity production is important as the difference of emitted CO2 between the accounting methods exceeds 650 kton/year for some scenarios. (author)

  4. Power generation and heating performances of integrated system of ammonia–water Kalina–Rankine cycle

    Highlights: • Integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) is investigated. • Ammonia–water Rankine cycle is operated for cogenerating room heating-water in winter. • Kalina cycle with higher efficiency is operated for power generation in other seasons. • Power recovery efficiency accounts thermal efficiency and waste heat absorbing ratio. • Heating water with 70 °C and capacity of 55% total reclaimed heat load is cogenerated. - Abstract: An integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) for power generation and heating is introduced. The Kalina cycle has large temperature difference during evaporation and small one during condensation therefore with high thermal efficiency for power generation, while the ammonia–water Rankine cycle has large temperature difference during condensation as well as evaporation, thus it can be adopted to generate heating-water as a by-product in winter. The integrated system is based on the Kalina cycle and converted to the Rankine cycle with a set of valves. The performances of the AWKRC system in different seasons with corresponding cycle loops were studied and analyzed. When the temperatures of waste heat and cooling water are 300 °C and 25 °C respectively, the thermal efficiency and power recovery efficiency of Kalina cycle are 20.9% and 17.4% respectively in the non-heating seasons, while these efficiencies of the ammonia–water Rankine cycle are 17.1% and 13.1% respectively with additional 55.3% heating recovery ratio or with comprehensive efficiency 23.7% higher than that of the Kalina cycle in heating season

  5. High Performance Operation Control for Heat Driven Heat Pump System using Metal Hydride

    Okamoto, Hideyuki; Masuda, Masao; Kozawa, Yoshiyuki

    lt is recognized that COP of heat driven heat pump system using metal hydride is 0.3-0.4 in general. In order to rise COP, we have proposed two kinds of specific operation control; the control of cycle change time according to cold heat load and the control of cooling water temperature according to outside air wet-bulb temperature. The characteristics of the heat pump system using metal hydride have grasped by various experiments and simulations. The validity of the simulation model has been confirmed by comparing with experimental results. As results of the simulations programmed for the actual operation control month by month, yearly COP has risen till 0.5-0.6 for practical scale air-conditioning system without regard for the building use. By the operation control hour by hour, yearly COP has risen till 0.6-0.65. Moreover, in the office building case added 40% sensible heat recovery, yearly COP has risen more than 0.8.

  6. Bulk additive system reduces mud costs and waste

    Today, personnel safety and environmental acceptability are high priorities in oil and gas operations. Many advances have been made, but packaging and handling of drilling mud has not changed in 35 years. In most cases, bulk barite is available, however, drilling muds are typically built from chemicals contained in 50 to 100-lb sacks or 5-gal buckets. Materials must be physically opened by rig personnel and mixed into drilling mud. Chemical exposure liability, and lifting or housekeeping related injuries associated with large quantities of packaging pose serious occupational safety risk. Figures from OSHA (1986) indicate that of 1,492 serious injury cases in Louisiana oil and gas operations, 42% were to back and lower extremities, 3% were eye injuries and 1% were chemical burns. Although exact figures are not available, experience suggests that a significant number of injuries are related to mud product physical handling. Another problem with current mud packaging is generated waste. Mud material lost because of broken sacks, inefficient transfer and as residue is unacceptable. Most mud engineers agree that 5 to 15% of mud products are lost or damaged on typical offshore jobs, depending on weather. When material that is spilled or left in packages, probably 2 to 3%, is added, the total is significant. Reusable containers for drilling mud products and manifold system design effectively eliminate these problems

  7. Molten Chloride Salts for Heat Transfer in Nuclear Systems

    Ambrosek, James Wallace

    2011-12-01

    A forced convection loop was designed and constructed to examine the thermal-hydraulic performance of molten KCl-MgCl2 (68-32 at %) salt for use in nuclear co-generation facilities. As part of this research, methods for prediction of the thermo-physical properties of salt mixtures for selection of the coolant salt were studied. In addition, corrosion studies of 10 different alloys were exposed to the KCl-MgCl2 to determine a suitable construction material for the loop. Using experimental data found in literature for unary and binary salt systems, models were found, or developed to extrapolate the available experimental data to unstudied salt systems. These property models were then used to investigate the thermo-physical properties of the LINO3-NaNO3-KNO 3-Ca(NO3), system used in solar energy applications. Using these models, the density, viscosity, adiabatic compressibility, thermal conductivity, heat capacity, and melting temperatures of higher order systems can be approximated. These models may be applied to other molten salt systems. Coupons of 10 different alloys were exposed to the chloride salt for 100 hours at 850°C was undertaken to help determine with which alloy to construct the loop. Of the alloys exposed, Haynes 230 had the least amount of weight loss per area. Nickel and Hastelloy N performed best based on maximum depth of attack. Inconel 625 and 718 had a nearly uniform depletion of Cr from the surface of the sample. All other alloys tested had depletion of Cr along the grain boundaries. The Nb in Inconel 625 and 718 changed the way the Cr is depleted in these alloys. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. A high temperature pump, thermal flow meter, and pressure differential device was designed, constructed and tested for use in the loop, The heat transfer of the molten chloride salt was found to

  8. Integrated system of nuclear reactor and heat exchanger

    The invention concerns PWRs in which the heat exchanger is associated with a pressure vessel containing the core and from which it can be selectively detached. This structural configuration applies to electric power generating uses based on land or on board ships. An existing reactor of this kind is fitted with a heat exchanger in which the tubes are 'U' shaped. This particular design of heat exchangers requires that the ends of the curved tubes be solidly maintained in a tube plate of great thickness, hence difficult to handle and to fabricate and requiring unconventional fine control systems for the control rods and awkward coolant pump arrangements. These complications limit the thermal power of the system to level below 100 megawatts. On the contrary, the object of this invention is to provide a one-piece PWR reactor capable of reaching power levels of 1500 thermal megawatts at least. For this, a pressure vessel is provided in the cylindrical assembly with not only a transversal separation on a plane located between the reactor and the heat exchanger but also a cover selectively detachable which supports the fine control gear of the control rods. Removing the cover exposes a part of the heat exchanger for easy inspection and maintenance. Further, the heat exchanger can be removed totally from the pressure vessel containing the core by detaching the cylindrical part, which composes the heat exchanger section, from the part that holds the reactor core on a level with the transversal separation

  9. Investigating the impact of heat demand reductions on Swedish district heating production using a set of typical system models

    Highlights: • Four typical district heating systems is defined to represent the entire Swedish DH sector. • A scenario for heat demand reductions due to building energy efficiency improvements is studied. • Heat demand reductions in Swedish district heating systems reduce CO2 emissions and reduce the use of biomass and fossil fuels. • The heat production in different district heating systems should be considered to maximise the reduction of CO2 emissions. - Abstract: The European Union (EU) aims at reducing its CO2 emissions and use of primary energy. The EU also aims to improve the energy efficiency in buildings and promote the use of combined heat and power (CHP) plants in district heating (DH) systems. Due to significant differences among DH systems regarding fuel use and heat production units, results for one individual DH systems are not generally valid for other DH systems. Therefore, there is a need to generally describe entire DH sectors in a way that considers the heat production plant merit-orders of the individual DH systems. Here, four models of typical DH systems are defined to represent the Swedish DH sector. A scenario for stepwise heat demand reductions due to building energy efficiency improvements is studied. The results show that heat demand reductions in Swedish DH systems generally reduce global CO2 emissions and mainly reduce the use of biomass and fossil fuels, while the use of waste and industrial waste heat (IWH) is less influenced. The results further show that in order to maximise the reduction of CO2 emissions by energy conservation in buildings, the heat production technologies of the DH system should be considered. A large share of CHP production with a high electricity-to-heat output ratio decreases the possibilities to reduce global CO2 emissions through heat demand reductions

  10. Experimental study on the effects of the number of heat exchanger modules on thermal characteristics in a premixed combustion system

    Yu, Byeonghun; Lee, Chang-Eon [Inha University, Incheon (Korea, Republic of); Kum, Sung Min [Halla University, Wonju (Korea, Republic of); Lee, Seungro [Chonbuk National University, Jeonju (Korea, Republic of)

    2016-01-15

    The effects of the number of heat exchanger modules on thermal characteristics were experimentally studied in a premixed combustion system with a cross-flow staggered-tube heat exchanger. The various heat exchanger modules, from 4 to 8, combined with a premixed burner were tested to investigate the performance of the heat exchanger through the surface area of the heat exchanger at various equivalence ratios. Additionally, the performance of the heat exchanger was analyzed by applying entropy generation theory to the heat exchanger system. As a result, although the heat transfer rate increases with the increase of the equivalence ratio, the NOx and CO concentrations also increase due to the increasing flame temperature. In addition, the entropy generation increases with an increase of the equivalence ratio. Furthermore, the heat transfer rate and the effectiveness are increased with the increase of the number of the heat exchanger modules. Also, the effectiveness is sharply increased when the number of the heat exchanger modules is increased from 4 to 5. Consequently, the optimal operating conditions regarding pollutant emission, effectiveness and entropy generation in this experimental range are 0.85 for the equivalence ratio and 8 for the number of heat exchanger modules.

  11. Experimental study on the effects of the number of heat exchanger modules on thermal characteristics in a premixed combustion system

    The effects of the number of heat exchanger modules on thermal characteristics were experimentally studied in a premixed combustion system with a cross-flow staggered-tube heat exchanger. The various heat exchanger modules, from 4 to 8, combined with a premixed burner were tested to investigate the performance of the heat exchanger through the surface area of the heat exchanger at various equivalence ratios. Additionally, the performance of the heat exchanger was analyzed by applying entropy generation theory to the heat exchanger system. As a result, although the heat transfer rate increases with the increase of the equivalence ratio, the NOx and CO concentrations also increase due to the increasing flame temperature. In addition, the entropy generation increases with an increase of the equivalence ratio. Furthermore, the heat transfer rate and the effectiveness are increased with the increase of the number of the heat exchanger modules. Also, the effectiveness is sharply increased when the number of the heat exchanger modules is increased from 4 to 5. Consequently, the optimal operating conditions regarding pollutant emission, effectiveness and entropy generation in this experimental range are 0.85 for the equivalence ratio and 8 for the number of heat exchanger modules

  12. Health Externalities and Heat savings in Energy System Modelling

    Zvingilaite, Erika

    and technologies, more remote location of energy plants and by reducing energy consumption. Considerable technical potential for energy demand reduction exists, particularly in buildings. In countries with cold climate, such as Denmark, energy demand for heating of buildings accounts for a significant share...... and included in an energy system optimisation model. The performed analysis of the Danish heat and power sector concludes that accounting for spatial variation of health damage costs in heat and power system optimisation model has an effect on the optimal technology mix and distribution of energy plants among...... and are popular as secondary heating technologies in Denmark, can cause indoor and outdoor air pollution locally. Hence, consumers can be exposed to their own air pollution, which can cause damage to their health. Such damage costs should be internalised in consumer decision making. The PhD study demonstrates...

  13. Heats of Mixing in Binary Systems of Molten Salts

    The heat of mixing is an important thermodynamic property in binary mixtures. As a result of the recent development of high-temperature calorimetry we have been able to determine directly the heat of mixing in binary systems of molten salts. In this work we present the results of thermochemical measurements carried out in our laboratories for the systems (Rb-K)Cl; (Rb-Na)Cl; (Ag-Na)Cl; (Na-K)Br and(Br-Cl)Na for different concentrations and temperatures. In our view, the most significant components of the heat of mixing are the ionic contribution and the polarization energy of the ions. Consequently, use could be made of a relation of the form: ΔHM = Qi - Qp. The heat of mixing can then have either positive or negative values depending on the sign and the preponderance of the Qi and Qp energies. (author)

  14. Implementing Geothermal Plants in the Copenhagen District Heating System

    Jensen, Louise Overvad; Hallgreen, Christine Erikstrup; Larsen, Esben

    2003-01-01

    The possibility of implementing geothermal heating in the Copenhagen district-heating system is assessed. This is done by building up general knowledge on the geological factors that influence the development of useable geothermal resources, factors concerning the exploration and utilization...... of geothermal energy in Denmark as well as the Danish potential, which, in former investigations, has been found to be around 100.000 PJ annually, and the economical potential is less, about 15 PJ/year. Since a considerable amount of the Danish power supply is tied to weather and the demand for heating......, an increasing demand for flexibility has been raised. Implementing geothermal heating would improve the flexibility in the Eastern Danish power system. Based on this information, as well as, on the hourly values of the expected production and consumption in 2010 and 2020, a model of the Copenhagen power...

  15. Heat savings in energy systems with substantial distributed generation

    Østergaard, PA

    2003-01-01

    . A lowered district heating demand and thereby lowered CHP-bound electricity generation would appear to increase the possibility of integration wind power but due to the ancillary services supplied by CHP plants, the situation is in fact the opposite. Heat savings may not be technically feasible, if...... a certain production is required regardless of whether over-all electricity generation is sufficient. This article analyses this and although heat savings do have a negative impact on the amount of wind power the system may integrate a given moment in certain cases, associated fuel savings are...

  16. Ventilation system with improved heat buffer; Ventilatieinrichting met verbeterde warmtebuffer

    Akkerman, H.

    1995-10-02

    The invention concerns heat buffers of a ventilation system in combination with heat recovery. Hot and a cold air flows through the buffer elements alternately, regulated by a valve. The buffer elements are placed in an improved framework by which the surface area (and thus the efficiency) is increased. Also rain caps can be integrated such that freezing up does not occur anymore and the pollution slows down, which also improves the efficiency and reduces the number of maintenance inspections. Finally, coupling pieces can be installed, by which chinks can be prevented, which again reduces the loss of efficiency between the heat buffer modules. 2 figs.

  17. Economics of residential solar hot water heating systems in Malaysia

    Malaysia has favorable climatic conditions for the development of solar energy due to the abundant sunshine and is considered good for harnessing energy from the sun. This is because solar hot water can represent the large energy consumer in Malaysian households but, because of the high initial cost of Solar Water Heating Systems (SWHSs) and easily to install and relatively inexpensive to purchase electric water heaters, many Malyaysian families are still using Electric Water Heaters to hot their water needs. This paper is presented the comparing of techno-economic feasibility of some models of SWHS from Malaysian's market with the Electric Water Heaters )EWH) by study the annual cost of operation for both systems. The result shows that the annual cost of the electrical water heater becomes greater than than the annual cost of the SWHS for all models in long-team run so it is advantageous for the family to use the solar water heater, at least after 4 years. In addition with installation SWHS the families can get long-term economical benefits, environment friendly and also can doing its part to reduce this country's dependence on foreign oil that is price increase day after day.(Author)

  18. Effect of heat treatment and packaging systems on the stability of fish sausage

    Bruna Rafaela Dallabona; Laura Beatriz Karam; Roberta Wagner; Dayse Aline Ferreira Silva Bartolomeu; Jorge Daniel Mikos; João Gabriel Phabiano Francisco; Renata Ernlund Freitas de Macedo; Peter Gaberz Kirschnik

    2013-01-01

    The purpose of this study was to evaluate the physicochemical and microbiological stability of sausages produced from mechanically separated fish meat (MSM) obtained from Nile tilapia filleting residues. Different heat treatments (pasteurization or smoking) and packaging systems (conventional or vacuum) were used. The sausages were characterized for chemical composition, weight loss, water activity, instrumental texture and sensorial analysis. Additionally, microbiological analysis, instrumen...

  19. Waste heat recovery system with new thermoelectric materials

    Borgström, Fredrik; Coyet, Jonas

    2015-01-01

    Increasing fuel prices, higher demands on "greener" transports and tougher international emission regulations puts requirements on companies in the automotive industry in improving their vehicle fuel efficiency. On a typical heavy duty Scania truck around 30% of the total fuel energy is wasted through the exhaust system in terms of heat dissipated to the environment. Hence, several investigations and experiments are conducted trying to find ways to utilize this wasted heat in what is called a...

  20. Combined system for heating and cooling entirely using solar energy

    The paper presents an original technical solution for heating and cooling of premises using solar energy only. The main equipment is thermo-pump fed by photo-voltaic system. This combination permits the conversion of 45% of the solar energy to heat regardless of winter conditions. It is investigated the possibility for the use of an inverter air conditioning installation to maintain the conditions

  1. Comparison of Systems for Levitation Heating of Electrically Conductive Bodies

    Ivo Dolezel

    2004-01-01

    Full Text Available Levitation heating of nonmagnetic electrically conductive bodies can be realized in various systems consisting of one of more inductors. The paper deals with compassion of the resultant. Lorentz lifts force acting on such a body (cylinder, sphere and velocity of its heating for different shapes of coils and parameters of the field currents (amplitudes, frequency. The tack is solved in quasi-coupled formulation. Theoretical considerations are supplemented with an illustrative example whose results are discussed.

  2. Time resolved heat exchange in driven quantum systems

    We study time-dependent heat transport in systems composed of a resonant level periodically forced with an external power source and coupled to a fermionic continuum. This simple model contains the basic ingredients to understand time resolved energy exchange in quantum capacitors that behave as single particle emitters. We analyse the behaviour of the dynamic heat current for driving frequencies within the non-adiabatic regime, showing that it does not obey a Joule dissipation law

  3. Heat of fusion storage systems for combined solar systems in low energy buildings

    Schultz, Jørgen Munthe; Furbo, Simon

    2004-01-01

    Solar heating systems for combined domestic hot water and space heating has a large potential especially in low energy houses where it is possible to take full advantage of low temperature heating systems. If a building integrated heating system is used – e.g. floor heating - the supply temperature...... (and the the return temperature) would only be a few degrees above room temperature due to the very low heating demand and the large heat transfer surface area. One of the objectives in a newly started IEA Task 32 project is to investigate and develop improved thermal storages for combined solar...... a stable super cooling, i.e. the material is able to cool down below its freezing point (Tfusion) and still be liquid, the possibility exist for a storage with a very low heat loss. When energy is needed from the storage the solidification is activated and the temperature rises almost instantly to...

  4. Recovery Act: Cedarville School District Retrofit of Heating and Cooling Systems with Geothermal Heat Pumps and Ground Source Water Loops

    Jarrell, Mark

    2013-09-30

    Cedarville School District retrofitted the heating and cooling systems in three campus areas (High School, Middle School, and Upper Elementary School) with geothermal heat pumps and ground source water loops, as a demonstration project for the effective implementation of geothermal heat pump systems and other energy efficiency and air quality improvements.

  5. Solar water heating system for a lunar base

    Somers, Richard E.; Haynes, R. Daniel

    1992-01-01

    An investigation of the feasibility of using a solar water heater for a lunar base is described. During the investigation, computer codes were developed to model the lunar base configuration, lunar orbit, and heating systems. Numerous collector geometries, orientation variations, and system options were identified and analyzed. The results indicate that the recommended solar water heater could provide 88 percent of the design load and would not require changes in the overall lunar base design. The system would give a 'safe-haven' water heating capability and use only 7 percent to 10 percent as much electricity as an electric heating system. As a result, a fixed position photovoltaic array can be reduced by 21 sq m.

  6. Optimization design of emergency decay heat removal system for CEFR

    Background: China experimental fast reactor (CEFR) is the first fast reactor in China, the piping designs are very important for the fast reactor. Purpose: The purpose is to improve the economy of pipeline design for the fast reactor. Methods: According to the optimization principles, redesign the support system of emergency decay heat removal system. Results: The piping of emergency decay heat removal system meets the ASME standard stress limit value under various prospective loads, and reduces the number of dampers, spring hangers. Conclusions: We accumulate layout experience for the support design of high temperature piping by the optimization design for emergency decay heat removal system, lay the foundation for the fast reactor piping design in the future. (authors)

  7. System design package for a solar heating and cooling system installed at Akron, Ohio

    1979-01-01

    Information used to evaluate the design of a solar heating, cooling, and domestic hot water system is given. A conventional heat pump provides summer cooling items as the design data brochure, system performance specification, system hazard analysis, spare parts list, and detailed design drawings. A solar system is installed in a single-family dwelling at Akron, Ohio, and at Duffield, Virginia.

  8. Heat transfer and fluid flow in nuclear systems

    Fenech, Henri

    1982-01-01

    Heat Transfer and Fluid in Flow Nuclear Systems discusses topics that bridge the gap between the fundamental principles and the designed practices. The book is comprised of six chapters that cover analysis of the predicting thermal-hydraulics performance of large nuclear reactors and associated heat-exchangers or steam generators of various nuclear systems. Chapter 1 tackles the general considerations on thermal design and performance requirements of nuclear reactor cores. The second chapter deals with pressurized subcooled light water systems, and the third chapter covers boiling water reacto

  9. Increasing RES Penetration and Security of Energy Supply by Use of Energy Storages and Heat Pumps in Croatian Energy System

    Krajačić, Goran; Mathiesen, Brian Vad; Duić, Neven;

    2010-01-01

    electricity, heat and transport demands, and including renewable energy, power plants, and combined heat and power production (CHP) for district heating. Using the 2007 energy system the wind power share is increased by two energy storage options: Pumped hydro and heat pumps in combination with heat storages......In this paper integration of wind power generation into the Croatian electricity supply is analysed using available technologies. The starting point is a model of the energy system in Croatia in 2007. Comprehensive hour-by-hour energy system analyses are conducted of a complete system meeting...... with specific regulation of power system could additionally increase wind penetration for 0.37 TWh. Hence, with the current technologies installed in the Croatian energy system the installed pumped hydro-plant may facilitate more than 10% wind power in the electricity system. Large-scale integration of...

  10. Planning of community heating systems modernization and development

    New approach to community heating systems modernization and development planning process has been proposed. It is based on the general decision making aid algorithm. The proposed algorithm takes into account both demand and supply side of community heat market modernization and development. The first step of algorithm - analytical step, refers to data base creation, which is needed for the description of community heating system energy, ecology and economic characteristics. Analysis of those characteristics allows for the identification of heating system market modernization and development potential scenarios. The second algorithm step - decision step, allows for the identification of the most compromise scenarios of system modernization and development. To make the planning process more transparent and to increase the influence of decision makers on the planning process the ELECTRE III method was chosen as the tool of decision aid. The ELECTRE III method is based on the construction of outranking relation and definition of pseudo-criterion. The iteration mode of method application allows the decision maker and analyst for the investigation of the sensitivity of final solution to the changing preference model. One of the methods of statistics - the creditability of mean range method was used for the determination of initial definition of pseudo-criterion. Proposed algorithm and decision aid method were employed for the case study analysis referring to the choice of the heating system for new developing urban area. (author)

  11. Prototype solar heating and cooling systems

    1979-01-01

    A combination of monthly progress reports are presented. It contains a summary of activities and progress made from November 1, 1978, to February 28, 1979. The effort calls for the development, manufacture, test, system installation, maintenance, problem resolution, and performance evaluation.

  12. Solar residential heating and cooling system development test program

    Humphries, W. R.; Melton, D. E.

    1974-01-01

    A solar heating and cooling system is described, which was installed in a simulated home at Marshall Space Flight Center. Performance data are provided for the checkout and initial operational phase for key subsystems and for the total system. Valuable information was obtained with regard to operation of a solar cooling system during the first summer of operation. Areas where improvements and modifications are required to optimize such a system are discussed.

  13. Problems encountered in solar heating and cooling systems

    Cash, M.

    1979-01-01

    Report discussing various experiences of workers at Marshall Space Flight Center in developing solar heating and cooling systems is presented. Presents compilation of problems and their resolutions which can assist designers of solar-energy systems and prevent repetition of errors.

  14. Backfitting the NANO bunkered emergency heat removal system at Beznau

    Baschek, Heinz

    1987-09-01

    Construction is due to start in 1988 of bunkered emergency heat removal systems at Beznau nuclear power station. Ten hours core cooling will be maintained by new emergency systems, located in bunkered buildings, in the event of a loss of primary coolant with the primary loop remaining intact.

  15. MATHEMATICAL MODELING OF THERMOPHYSICAL PARAMETERS OF VORTEX HEAT EXCHANGER OF HEATING SYSTEMS OF GAS DISTRIBUTION POINTS PREMISES

    V. A. Lapin; V. N. Melkumov; A. N. Kobelev

    2009-01-01

    The mathematical model of heat transfer in vortex heat exchanger using natural gas energy which is released under decompression in gas-main pipe-lines for consumers of gas supply systems (dwellings, public and industrial buildings).

  16. Application possibilities for nuclear heating plants in the energy system of the Federal Republic of Germany

    The field of application for nuclear heating plants is the so-called low-temperature heating market. It includes the energy demand for space heating, hot water an low-temperature process heat. The analysis of technical potentials for heating reactors considers two different levels. The structure of the district heating system determines the technical potential in the now existing energy system, it amounts to a total power of 9,8 to 14,3 GWth of heating reactors. For a possible extended use of heating reactors in future which goes beyond the existing district heating system the technical circumstances and the local distribution of the low-temperature heating market define the technical potential which ranges from 126 to 160 GWth on todays basis. The chance of implementing nuclear heating plants is strongly influenced by the economy of their heat generation. The economic situation of heat generation with heating reactors is estimated in comparison to current fossil district heating production systems. In the low-temperature heating market the heat supply by nuclear fed district heating systems is compared to the heat production in houses. Considering the assumptions the analysis indicates that nuclear heating plants can compete with existing fossil heat sources. The analysis shows that heating reactors are an interesting and powerful option for the supply of the district heating market in future. The underlying economic assumptions would allow the use of nuclear heating plants and it seems that they could contribute to reduce the environmental stress. (orig.)

  17. Method and means for heating buildings in a district heating system with waste heat from a thermal power plant

    The waste heat from a thermal power plant is transported through a municipal heating network to a plurality of buildings to be heated. The quantity of heat thus supplied to the buildings is higher than that required for the heating of the buildings. The excess heat is released from the buildings to the atmosphere in the form of hot air

  18. Residual heat use generated by a 12 kW fuel cell in an electric vehicle heating system

    A diesel or gasoline vehicle heating is produced by the heat of the engine coolant liquid. Nevertheless, electric vehicles, due to the fact that electric motor transform directly electricity into mechanical energy through electromagnetic interactions, do not generate this heat so other method of providing it has to be developed. This study introduces the system developed in a fuel cell electric vehicle (lithium-ion battery – fuel cell) with residual heat use. The fuel cell electric vehicle is driven by a 12 kW PEM (proton exchange membrane) fuel cell. This fuel cell has an operating temperature around 50 °C. The residual heat generated was originally wasted by interaction with the environment. The new developed heating system designed integrates the heat generated by the fuel cell into the heating system of the vehicle, reducing the global energy consumption and improving the global efficiency as well. - Highlights: • Modification of heating system was done by introducing the residual heat from fuel cell. • Maximum heat achieved by the heating radiator of 9.27 kW. • Reduction of the heat dissipation by the fuel cell cooling system 1.5 kW. • Total efficiency improvement of 20% with an autonomy increase of 21 km

  19. Circuit breaker for OHMIC-heating systems

    A circuit breaker for power amplification in inductive energy storage systems is described using commercially ac breakers in connection with a ''High-Pressure-Breaking-Element'' (HPBE). Dimensioning values for the HPBE are given. Currents up to 30 kA have been interrupted by paralleling 3 HPBEs. With one HPBE a current of 10 kA was switched off producing a voltage of 30 kV

  20. Development of KSTAR Neutral Beam Heating System

    Oh, B. H.; Song, W. S.; Yoon, B. J. (and others)

    2007-10-15

    The prototype components of a neutral beam injection (NBI) system have been developed for the KSTAR, and a capability of the manufactured components has been tested. High power ion source, acceleration power supply, other ion source power supplies, neutralizer, bending magnet for ion beam separation, calorimeter, and cryo-sorption pump have been developed by using the domestic technologies and tested for a neutral beam injection of 8 MW per beamline with a pulse duration of 300 seconds. The developed components have been continuously upgraded to achieve the design requirements. The development technology of high power and long pulse neutral beam injection system has been proved with the achievement of 5.2 MW output for a short pulse length and 1.6 MW output for a pulse length of 300 seconds. Using these development technologies, the domestic NB technology has been stabilized under the development of high power ion source, NB beamline components, high voltage and current power supplies, NB diagnostics, NB system operation and control.

  1. Efficiency and cost analysis of a designed in-line water heating system compared to a conventional water heating system in South Africa

    Gouws, Rupert; Le Roux, Estie

    2012-01-01

    In this paper, the authors compares the efficiency and cost of a designed in-line water heating system with a conventional water heating system (geyser) in South Africa. The paper provides an overview on water heating systems and heating elements and provides the typical water consumption required by an average household in South Africa. A summary on the design of the in-line water heating system together with a system cost analysis is provided. The designed in-line water heating system ta...

  2. Ultrasonic temperature profiling system for detecting critical heat flux in non-uniformly heated tube bundles

    A new ultrasonic instrument system was developed and applied to the problem of detecting critical heat flux (CHF) in experiments that simulate a nuclear reactor fuel assembly. This instrumentation system used the principles of ultrasonic thermometry to detect and localte CHF in a tube bundle with non-uniform axial heat generation. The technique consists of measuring the time between pairs of ultrasonic echoes that reflect from a sequence of evenly spaced discontinuities along a sensor. Each measurement of time is directly related to the temperature of a specific segment of a sensor. The system was designed to handle many 16-zone sensors at a high rate of data acquisition so that CHF could be rapidly detected and accurately located. This paper includes a description of the sensor and the signal processing techniques as well as examples of the system's response to CHF

  3. A modeling approach for district heating systems with focus on transient heat transfer in pipe networks

    Mohammadi, Soma; Bojesen, Carsten

    2015-01-01

    operational temperature. However, in order to implement low temperature concept for existing DH systems, there is a need to apply a stepwise changes in the existing systems. This study emphasis on improving the existing DH pipes networks. For this purpose the first step is developing a model, which comprises...... approximately 14 km pipelines (supply and return pipes). At the first stage, the Studstrup DH system is developed in TERMIS, which is commercial software for district heating system simulation, and then the developed model is validated and compared with the results obtained from TERMIS and measurements. The...... TERMIS model is already validated towards measurements. This paper explains the developed model, which is going to be used for performing possible scenarios to improve the existing DHN from heat and temperature loss viewpoints. Moreover, it provides a platform to add and extend different aspect of DH...

  4. Behavior study on Na heat pipe in passive heat removal system of new concept molten salt reactor

    The high temperature Na heat pipe is an effective device for transporting heat, which is characterized by remarkable advantages in conductivity, isothermally and passively working. The application of Na heat pipe on passive heat removal system of new concept molten salt reactor (MSR) is significant. The transient performance of high temperature Na heat pipe was simulated by numerical method under the MSR accident. The model of the Na heat pipe was composed of three conjugate heat transfer zones, i.e. the vapor, wick and wall. Based on finite element method, the governing equations were solved by making use of FORTRAN to acquire the profiles of the temperature, velocity and pressure for the heat pipe transient operation. The results show that the high temperature Na heat pipe has a good performance on operating characteristics and high heat transfer efficiency from the frozen state. (authors)

  5. An Overview of Liquid Fluoride Salt Heat Transport Systems

    Holcomb, David Eugene [ORNL; Cetiner, Sacit M [ORNL

    2010-09-01

    Heat transport is central to all thermal-based forms of electricity generation. The ever increasing demand for higher thermal efficiency necessitates power generation cycles transitioning to progressively higher temperatures. Similarly, the desire to provide direct thermal coupling between heat sources and higher temperature chemical processes provides the underlying incentive to move toward higher temperature heat transfer loops. As the system temperature rises, the available materials and technology choices become progressively more limited. Superficially, fluoride salts at {approx}700 C resemble water at room temperature being optically transparent and having similar heat capacity, roughly three times the viscosity, and about twice the density. Fluoride salts are a leading candidate heat-transport material at high temperatures. Fluoride salts have been extensively used in specialized industrial processes for decades, yet they have not entered widespread deployment for general heat transport purposes. This report does not provide an exhaustive screening of potential heat transfer media and other high temperature liquids such as alkali metal carbonate eutectics or chloride salts may have economic or technological advantages. A particular advantage of fluoride salts is that the technology for their use is relatively mature as they were extensively studied during the 1940s-1970s as part of the U.S. Atomic Energy Commission's program to develop molten salt reactors (MSRs). However, the instrumentation, components, and practices for use of fluoride salts are not yet developed sufficiently for commercial implementation. This report provides an overview of the current understanding of the technologies involved in liquid salt heat transport (LSHT) along with providing references to the more detailed primary information resources. Much of the information presented here derives from the earlier MSR program. However, technology has evolved over the intervening years

  6. Heat transfer effect of entrained gas in liquid sodium systems

    An analysis was made and a correlation developed to determine the reduction in heat transfer caused by entrained inert gas in sodium-cooled liquid metal systems. A 1% void fraction (1.62% volumetric flow rate of inert gas) is calculated to reduce the heat transfer coefficient by approximately 4% in a typical LMFBR. This reduction will not occur over the entire reactor, but only near the inlet of the radial blanket. It was concluded that a reduction in heat transfer in a system having a low oxygen concentration (0C (10000F), if the Reynolds number is greater than approximately 105, and if the operating time is longer than that required for complete wetting at the reference temperature, no reduction in heat transfer is expected. The cause of the reduction in heat transfer is postulated to be a reduction in the thermal conductivity of a two-phase sodium-gas lay er near the heated surface. It is proposed to calculate the thermal conductivity reduction using the average inert gas void fraction and a sintered-metal model. (Auth.)

  7. Water heating solar system using collector with polycarbonate absorber surface

    Souza, Luiz Guilherme Meira de; Sodre, Dilton; Cavalcanti, Eduardo Jose Cidade; Souza, Luiz Guilherme Vieira Meira de; Mendes, Jose Ubiragi de Lima [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)], e-mails: lguilherme@dem.ufrn.br, diltonsodre@ifba.edu.br, ubiragi@ct.ufrn.br

    2010-07-01

    It is presented s solar collector to be used in a heating water for bath system, whose main characteristics are low cost and easy fabrication and assembly processes. The collector absorber surface consists of a polycarbonate plate with an area of 1.5 m{sup 2}. The water inlet and outlet are made of PVC 50mm, and were coupled to a 6mm thick polycarbonate plate using fiberglass resin. A 200 liters thermal reservoir will be used. This reservoir is also alternative. The absorber heating system works under thermo-siphon regimen. Thermal parameters will be evaluated to prove the feasibility of the studied solar heating system to obtain bath water for a four people family. (author)

  8. Sample heating system for spin-polarized scanning electron microscopy.

    Kohashi, Teruo; Motai, Kumi

    2013-08-01

    A sample-heating system for spin-polarized scanning electron microscopy (spin SEM) has been developed and used for microscopic magnetization analysis at temperatures up to 500°C. In this system, a compact ceramic heater and a preheating operation keep the ultra-high vacuum conditions while the sample is heated during spin SEM measurement. Moreover, the secondary-electron collector, which is arranged close to the sample, was modified so that it is not damaged at high temperatures. The system was used to heat a Co(1000) single-crystal sample from room temperature up to 500°C, and the magnetic-domain structures were observed. Changes of the domain structures were observed around 220 and 400°C, and these changes are considered to be due to phase transitions of this sample. PMID:23349241

  9. Removal heat extraction systems in advanced reactors

    The two main problems generally attributed to the electricity generation by nuclear power are the security of the facility and the radioactivity of the nuclear wastes, in a way that the only tasks of the European Commission on this matter are to make sure a high level of security in the facilities, as well as an adequate fuel and waste management. In this paper we discuss about the main lines in which the CIEMAT and the Polytechnic University of Valencia are working relative to the study of the passive working systems of the advanced designs reactors. (Author) 24 refs

  10. Optimization of microwave heating in an existing cubicle cavity by incorporating additional wave guide and control components

    The use of microwave energy to thermally treat Low Level (LLW), Transuranic (TRU), and mixed waste has been under development at the Rocky Flats Environmental Technology Site (Site) since 1986. During that time, the technology has progressed from bench-scale tests, through pilot-scale tests, and finally to a full-scale demonstration unit. Experimental operations have been conducted on a variety of non-radioactive surrogates and actual radioactive waste forms. Through these studies and development efforts, the Microwave Vitrification Engineering Team (MVET) at Rocky Flats has successfully proven the application of microwave energy for waste treatment operations. In the microwave solidification process, microwave energy is used to heat a mixture of waste and glass frit to produce a vitrified product that meets all the current acceptance criteria at the final disposal sites. All of the development to date has utilized a multi-mode microwave system to provide the energy to treat the materials. Currently, evaluations are underway on modifications to the full-scale demonstration system that provide a single-mode operation as a possible method to optimize the system. This poster presentation describes the modifications made to allow the single-mode operation

  11. Preliminary Test of a small heat pipe for hybrid control rod in-core passive decay heat removal system

    This paper introduces 'Hybrid control rod' combining its original function and heat removal ability. The high temperature operation and high resistance of radiation should be considered to adopt the hybrid heat pipe at the in-core condition. Other design consideration is to make extra inlet parts because it has a high risk of inlet boundary failure. It means that the introduction of heat pipe system is difficult to present nuclear power plants. The other concepts are presented to out-core cooling design but it has low performance compared with in-core heat removal system. Hybrid heat pipe for in-core heat removal system suggests the solution of these problems. Ultimate objective of this research is to develop the passive emergency decay heat removal system using hybrid heat pipes targeting design bases accidents such as station black-out (SBO) and small break loss of coolant accident (SBLOCA). The purpose of this work is to confirm the performance and heat transfer behavior of hybrid heat pipe. The hybrid heat pipe has special condition for operation. Therefore, it is hard to analyze their behavior in core. Table I shows the characteristics of hybrid heat pipe and consideration for manufacturing the heat pipe

  12. Preliminary Test of a small heat pipe for hybrid control rod in-core passive decay heat removal system

    Kim, In Guk; Ban, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    This paper introduces 'Hybrid control rod' combining its original function and heat removal ability. The high temperature operation and high resistance of radiation should be considered to adopt the hybrid heat pipe at the in-core condition. Other design consideration is to make extra inlet parts because it has a high risk of inlet boundary failure. It means that the introduction of heat pipe system is difficult to present nuclear power plants. The other concepts are presented to out-core cooling design but it has low performance compared with in-core heat removal system. Hybrid heat pipe for in-core heat removal system suggests the solution of these problems. Ultimate objective of this research is to develop the passive emergency decay heat removal system using hybrid heat pipes targeting design bases accidents such as station black-out (SBO) and small break loss of coolant accident (SBLOCA). The purpose of this work is to confirm the performance and heat transfer behavior of hybrid heat pipe. The hybrid heat pipe has special condition for operation. Therefore, it is hard to analyze their behavior in core. Table I shows the characteristics of hybrid heat pipe and consideration for manufacturing the heat pipe.

  13. Calculation methods for SPF for heat pump systems for comparison, system choice and dimensioning

    Nordman, Roger; Andersson, Kajsa; Axell, Monica; Lindahl, Markus

    2010-09-15

    In this project, results from field measurements of heat pumps have been collected and summarised. Also existing calculation methods have been compared and summarised. Analyses have been made on how the field measurements compare to existing calculation models for heat pumps Seasonal Performance Factor (SPF), and what deviations may depend on. Recommendations for new calculation models are proposed, which include combined systems (e.g. solar - HP), capacity controlled heat pumps and combined DHW and heating operation

  14. Internal dust recirculation system for a fluidized bed heat exchanger

    Gamble, Robert L.; Garcia-Mallol, Juan A.

    1981-01-01

    A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided in a heat exchange relation to the bed and includes a steam drum disposed adjacent the bed and a tube bank extending between the steam drum and a water drum. The tube bank is located in the path of the effluent gases exiting from the bed and a baffle system is provided to separate the solid particulate matter from the effluent gases. The particulate matter is collected and injected back into the fluidized bed.

  15. Heat transfer study on dry vault storage system

    IHI has been studying the dry vault storage system based on the experience of the vitrified products storage facility. Maximum allowable temperature of fuel cladding was decided by creep strain criteria for long term dry storage environment to avoid cladding degradation. It was necessary to establish the evaluation method of heat transfer inside and outside the fuel loaded canisters for the design of storage facility. Therefore, the experimental and analytical studies of heat transfer of dry vault storage system were carried out using the experimental apparatus and the analysis program based on finite element method. (author)

  16. Solar dynamic organic Rankine cycle heat rejection system simulation

    Havens, V. N.; Ragaller, D. R.; Namkoong, D.

    1987-01-01

    The use of a rotary fluid management device (RFMD) and shear flow condenser for two-phase fluid management in microgravity organic Rankine cycle (ORC) applications is examined. A prototype of the proposed Space Station ORC heat rejection system was constructed to evaluate the performance of the inventory control method. The design and operation of the RFMD, shear flow condenser, and inventory control fluid accumulator are described. A schematic diagram of the ORC, RFMD, and condenser, and a functional diagram of the heat rejection system for the ORC are presented.

  17. Solar heating and hot water system installed at Listerhill, Alabama

    1978-12-01

    The solar system was installed into a new buildng and was designed to provide 79% of the estimated annual space heating load and 59% of the estimated annual potable hot water requirement. The collectors are flat plate, liquid manufactured by Reynolds Metals Company and cover a total area of 2344 square feet. The storage medium is water inhibited with NALCO 2755 and the container is an underground, unpressurized steel tank with a capacity of 5000 gallons. This final report describes in considerable detail the solar heating facility and contains detailed drawings of the completed system.

  18. Advances in the optimisation of apparel heating products: A numerical approach to study heat transport through a blanket with an embedded smart heating system

    The optimisation of the performance of products with smart/active functionalities (e. g. in protective clothing, home textiles products, automotive seats, etc.) is still a challenge for manufacturers and developers. The aim of this study was to optimise the thermal performance of a heating product by a numerical approach, by analysing several opposing requirements and defining solutions for the identified limitations, before the construction of the first prototype. A transfer model was developed to investigate the transport of heat from the skin to the environment, across a heating blanket with an embedded smart heating system. Several parameters of the textile material and of the heating system were studied, in order to optimise the thermal performance of the heating blanket. Focus was put on the effects of thickness and thermal conductivity of each layer, and on parameters associated with the heating elements, e.g. position of the heating wires relative to the skin, distance between heating wires, applied heating power, and temperature range for operation of the heating system. Furthermore, several configurations of the blanket (and corresponding heating powers) were analysed in order to minimise the heat loss from the body to the environment, and the temperature distribution along the skin. The results show that, to ensure an optimal compromise between the thermal performance of the product and the temperature oscillation along its surface, the distance between the wires should be small (and not bigger than 50 mm), and each layer of the heating blanket should have a specific thermal resistance, based on the expected external conditions during use and the requirements of the heating system (i.e. requirements regarding energy consumption/efficiency and capacity to effectively regulate body exchanges with surrounding environment). The heating system should operate in an ON/OFF mode based on the body heating needs and within a temperature range specified based on

  19. Techno-economic evaluation of a solar assisted combined heat pump – Organic Rankine Cycle system

    Highlights: • Addition of an ORC to a solar thermal and ground source heat pump system. • Additional investments comprise only 400 € for a single-family house unit. • Recharging the ground during ORC has negligible impact on the COP of the HP. • Economics studied for application in Bochum, Denver and Ankara; only small benefits. • Use of isobutane instead of R134a would increase the profit of the ORC system. - Abstract: The economic feasibility of the addition of an ORC to a combined solar system coupled to a ground-source heat pump is discussed. The ORC prevents the stagnation of the solar loop and reverses the heat pump cycle. The working fluid is evaporated in the condenser of the heat pump, expanded in the scroll compressor, which becomes a scroll expander, and condensed in the brine heat exchanger. The only additional investments for the ORC system comprise a pump, valves and upgraded controls and are estimated to be 400 € for a single-family-house unit. Flat-plate collectors are the preferred collector type as the higher collector efficiency of evacuated tube collectors does not outweigh the higher costs. The thermal recharging of the ground during ORC has a negligible impact on the COP of the heat pump. However, the recharging leads to less deep boreholes compared to a conventional system. Because of the low investments for the ORC, even small reductions in borehole depth make a significant contribution to the economic feasibility of the system. The addition of the ORC overall generates a small profit of 155 € at Ankara and 74 € at Denver for a rocky soil and a thermally enhanced grout. On the contrary, the conventional solar combisystem coupled to a ground source heat pump was found to be economically unreasonable at all locations. The working fluid isobutane is interesting for future applications because of the lower global warming potential and the smaller saturation pressures compared to R134a. The latter allow for the installation of a

  20. BETTER DUCT SYSTEMS FOR HOME HEATING AND COOLING.

    ANDREWS,J.

    2001-01-01

    This is a series of six guides intended to provide a working knowledge of residential heating and cooling duct systems, an understanding of the major issues concerning efficiency, comfort, health, and safety, and practical tips on installation and repair of duct systems. These guides are intended for use by contractors, system designers, advanced technicians, and other HVAC professionals. The first two guides are also intended to be accessible to the general reader.