14 CFR 29.1103 - Induction systems ducts and air duct systems.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction systems ducts and air duct systems. 29.1103 Section 29.1103 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Induction System § 29.1103 Induction systems ducts and air duct...

CFD Analysis to Study Effect of Circular Vortex Generator Placed in Inlet Section to Investigate Heat Transfer Aspects of Solar Air Heater

Directory of Open Access Journals (Sweden)

Vipin B. Gawande

2014-01-01

Full Text Available CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate.

CFD analysis to study effect of circular vortex generator placed in inlet section to investigate heat transfer aspects of solar air heater.

Science.gov (United States)

Gawande, Vipin B; Dhoble, A S; Zodpe, D B

2014-01-01

CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate.

Study of natural convection heat transfer characteristics. (1) Influence of ventilation duct height

International Nuclear Information System (INIS)

Wakamatsu, Mitsuo; Iwaki, Chikako; Ikeda, Tatsumi; Morooka, Shinichi; Ikeda, Hiroshi; Nakada, Kotaro; Masaki, Yoshikazu

2008-01-01

Natural cooling system has been investigated in waste storage. It is important to evaluate the flow by natural draft enough to removal the decay heat from the waste. In this study, we carried out the fundamental experiment of ventilation duct height effect for natural convection on vertical cylindrical heater in atmospheric air. The scale of test facility is about 4m height with single heater. The heating value is varied in the range of 33-110W, where Rayleigh number is over 10 10 . Natural convection flow rate were calculated by measured velocity with thermo anemometer in the inlet duct. The temperature of the cylindrical heater wall and fluid were measured with thermocouples. It was found that the heat transfer coefficient difference between long duct and short duct is small in this experiment. (author)

ECOLO-HOUSE in the snowy town. Study of the ventilating function what the heat collecting system of the air duct utilizing attic has; Yukiguni ECOLO-HOUSE. Kison kaoku no yaneura wo riyoshita duct shunetsu system

Energy Technology Data Exchange (ETDEWEB)

Umemiya, H; Hirosawa, K [Yamagata University, Yamagata (Japan)

1996-10-27

Described in this paper is an air duct heat collecting system, forming a link in the chain of natural energy utilization, in an attic of a house actually in presence. When a sirocco fan (blowing air from an indoor induction duct into the room) at the base of the highblocked floor is turned, air is sucked through an air intake under the eaves into a heat collecting duct (constructed utilizing the tilt roof and rafter). Heat from the roof warmed by sunshine is absorbed by air in the heat collecting duct and is fed to the highblocked floor structure through a heat collecting room and the induction duct. This system functions quite effectively as a ventilating device. Dew condensation on the walls and floor and musty smell have been eliminated. This system is good enough as a heater even on chilly days in early spring when there is sunshine. In the time zone with the sun shining, the system collects 4{times}10{sup 4}kJ per day, exhibiting a heat collecting efficiency of 4%. The heat collecting duct was analyzed for thermal environment, and the heat flux of the collected heat was determined as Qk(W/m{sup 2}=0.1{times}I-1.3{Theta}d-{Theta}a). In this equation, I is the quantity of insolation (W/m{sup 2}), {Theta}d is the temperature in the heat collecting duct, and {Theta}a is the free air temperature. 2 refs., 8 figs.

Flat plate solar air heater with latent heat storage

Science.gov (United States)

Touati, B.; Kerroumi, N.; Virgone, J.

2017-02-01

Our work contains two parts, first is an experimental study of the solar air heater with a simple flow and forced convection, we can use thatlaste oneit in many engineering's sectors as solardrying, space heating in particular. The second part is a numerical study with ansys fluent 15 of the storage of part of this solar thermal energy produced,using latent heat by using phase change materials (PCM). In the experimental parts, we realize and tested our solar air heater in URER.MS ADRAR, locate in southwest Algeria. Where we measured the solarradiation, ambient temperature, air flow, thetemperature of the absorber, glasses and the outlet temperature of the solar air heater from the Sunrise to the sunset. In the second part, we added a PCM at outlet part of the solar air heater. This PCM store a part of the energy produced in the day to be used in peak period at evening by using the latent heat where the PCMs present a grateful storagesystem.A numerical study of the fusion or also named the charging of the PCM using ANSYS Fluent 15, this code use the method of enthalpies to solve the fusion and solidification formulations. Furthermore, to improve the conjugate heat transfer between the heat transfer fluid (Air heated in solar plate air heater) and the PCM, we simulate the effect of adding fins to our geometry. Also, four user define are write in C code to describe the thermophysicalpropriety of the PCM, and the inlet temperature of our geometry which is the temperature at the outflow of the solar heater.

Performance evaluation of a natural-convection solar air-heater with a rectangular-finned absorber plate

International Nuclear Information System (INIS)

Fakoor Pakdaman, M.; Lashkari, A.; Basirat Tabrizi, H.; Hosseini, R.

2011-01-01

This paper deals with an experimental investigation to evaluate different thermal characteristics of a natural-convection flat-plate solar air-heater with longitudinal rectangular fins array. Having determined the thermal performance of the system a Nusselt number correlation is presented for such finned duct devices. In the presented empirical model which may have industrial applications, solar radiation and ambient temperature have been considered as independent parameters. Other characteristics of the system such as different dimensionless variables, plates and outflow temperatures, efficiency, and mass flow rate have been empirically modeled based on these variables. The particular difference in this study in comparison with the other similar studies is the presentation of an empirical model for rectangular-finned solar air-heaters. This model proposes design concepts and rules of thumb, and demonstrates the calculations of the design parameters. Based on the order of magnitude analysis, solar radiation has been found to be the main parameter which characterizes the thermal behavior of the system. Besides, exergy analysis has been carried out, and optimum conditions in which the system has the highest performance have been determined.

Exergy Based Performance Analysis of Double Flow Solar Air Heater with Corrugated Absorber

OpenAIRE

S. P. Sharma; Som Nath Saha

2017-01-01

This paper presents the performance, based on exergy analysis of double flow solar air heaters with corrugated and flat plate absorber. A mathematical model of double flow solar air heater based on energy balance equations has been presented and the results obtained have been compared with that of a conventional flat-plate solar air heater. The double flow corrugated absorber solar air heater performs thermally better than the flat plate double flow and conventional flat-plate solar air heate...

Optimum design of the injection duct system of a stenter machine

Energy Technology Data Exchange (ETDEWEB)

Juraeva, Makhsuda; Song, Dong Joo [Yeungnam University, Geyongsan (Korea, Republic of); Ryu, Kyung Jin [Ajou Motor College, Boryeong (Korea, Republic of)

2017-05-15

Stenter machines are used for drying fabrics in the textile industry and have a heater, injection duct system, and fans inside a chamber. The injection duct system has ducts and air-injecting holes. Plane-type injection duct systems were investigated to obtain uniform airflow at the air-injecting holes. The flow field of the injection duct systems was computed using ANSYS CFX with different heights of the duct end and different shapes for the air-injecting holes. There was a high mass flow rate at the air-injecting holes and high airflow circulation inside both plane-type and mountain-type ducts at the ends. The height of the duct end was varied between 40 mm and 160 mm. The injection duct systems were analyzed with four different shapes of air-injecting holes. The circular and elliptical holes had lower standard deviations of the mass flow rate than other shapes. Relatively uniform mass flow rates were obtained in the plane-type and mountain-type duct systems when the height of the duct end was 40 mm and the shape of the air-injecting holes was circular or elliptical. The developed injection duct systems were improved by obtaining a uniform mass flow rate at the air-injecting holes. A stenter prototype was fabricated with the developed injection duct system to confirm the numerical results. The developed injection duct system had better performance than the original system.

Thermal behaviour of solar air heater with compound parabolic concentrator

International Nuclear Information System (INIS)

Tchinda, Rene

2008-01-01

A mathematical model for computing the thermal performance of an air heater with a truncated compound parabolic concentrator having a flat one-sided absorber is presented. A computer code that employs an iterative solution procedure is constructed to solve the governing energy equations and to estimate the performance parameters of the collector. The effects of the air mass flow rate, the wind speed and the collector length on the thermal performance of the present air heater are investigated. Predictions for the performance of the solar heater also exhibit reasonable agreement, with experimental data with an average error of 7%

Distributed Nonstationary Heat Model of Two-Channel Solar Air Heater

International Nuclear Information System (INIS)

Klychev, Sh. I.; Bakhramov, S. A.; Ismanzhanov, A. I.; Tashiev, N.N.

2011-01-01

An algorithm for a distributed nonstationary heat model of a solar air heater (SAH) with two operating channels is presented. The model makes it possible to determine how the coolant temperature changes with time along the solar air heater channel by considering its main thermal and ambient parameters, as well as variations in efficiency. Examples of calculations are presented. It is shown that the time within which the mean-day efficiency of the solar air heater becomes stable is significantly higher than the time within which the coolant temperature reaches stable values. The model can be used for investigation of the performances of solar water-heating collectors. (authors)

Design data brochure: Solar hot air heater

Science.gov (United States)

1978-01-01

The design, installation, performance, and application of a solar hot air heater for residential, commercial and industrial use is reported. The system has been installed at the Concho Indian School in El Reno, Oklahoma.

Thermal behaviour of a solar air heater with a compound parabolic concentrator

International Nuclear Information System (INIS)

Tchinda, R.

2005-11-01

A mathematical model for computing the thermal performance of an air heater with a truncated compound parabolic concentrator having a flat one-sided absorber is presented. A computed code that employs an iterative solution procedure is constructed to solve the governing energy equations and to estimate the performance parameters of the collector. The effects of the air mass flow rate, the wind speed and the collector length on the thermal performance of the present air heater are investigated. Prediction for the performance of the solar heater also exhibits reasonable agreement with experimental data with an average error of 7%. (author)

Effect of Collector Aspect Ratio on the Thermal Performance of Wavy Finned Absorber Solar Air Heater

OpenAIRE

Abhishek Priyam; Prabha Chand

2016-01-01

A theoretical investigation on the effect of collector aspect ratio on the thermal performance of wavy finned absorber solar air heaters has been performed. For the constant collector area, the various performance parameters have been calculated for plane and wavy finned solar air heaters. It has been found that the performance of wavy finned solar air heater improved with the increase in the collector aspect ratio. The performance of wavy finned solar air heater has been found 30 percent hig...

Discussion on Boiler Efficiency Correction Method with Low Temperature Economizer-Air Heater System

Science.gov (United States)

Ke, Liu; Xing-sen, Yang; Fan-jun, Hou; Zhi-hong, Hu

2017-05-01

This paper pointed out that it is wrong to take the outlet flue gas temperature of low temperature economizer as exhaust gas temperature in boiler efficiency calculation based on GB10184-1988. What’s more, this paper proposed a new correction method, which decomposed low temperature economizer-air heater system into two hypothetical parts of air preheater and pre condensed water heater and take the outlet equivalent gas temperature of air preheater as exhaust gas temperature in boiler efficiency calculation. This method makes the boiler efficiency calculation more concise, with no air heater correction. It has a positive reference value to deal with this kind of problem correctly.

An experimental evaluation of multi-pass solar air heaters

Energy Technology Data Exchange (ETDEWEB)

Satcunanathan, S.; Persad, P.

1980-12-01

Three collectors of identical dimensions but operating in the single-pass, two-pass and three-pass modes were tested simultaneously under ambient conditions. It was found that the two-pass air heater was consistently better than the single-pass air heater over the day for the range of mass flow rates considered. It was also found that at a mass flow rate of 0.0095 kg s/sup -1/ m/sup -2/, the thermal performances of the two-pass and three-pass collectors were identical, but at higher flow rates the two-pass collector was superior to the three-pass collector, the superiority decreasing with increasing mass flow rate.

EXPERIMENTAL STUDY ON DOUBLE PASS SOLAR AIR HEATER WITH MESH LAYERS AS ABSORBER PLATE

Directory of Open Access Journals (Sweden)

Raheleh Nowzaria

2014-01-01

Full Text Available The double pass solar air heater is constructed and tested for thermal efficiency at a geographic location of Cyprus in the city of Famagusta. The absorber plate was replaced by fourteen steel wire mesh layers, 0.2 × 0.2 cm in cross section opening, and they were fixed in the duct parallel to the glazing. The distance between each set of wire mesh layers is 0.5cm to reduce the pressure drop. The wire mesh layers were painted with black before installing them into the collector. The obtained results show that as the mass flow rate increases, the efficiency of the system also increases. The temperature difference (ΔT between the inlet and outlet air through the system increases as the mass flow rate decreases. The maximum ΔT (53°C is achieved at the flow rate of 0.011 kg/s. The range of the mass flow rate used in this work is between 0.011 and 0.037 kg/s. It is also found that the average efficiency obtained for the double pass air collector is 53.7% for the mass flow rate of 0.037 kg/s.

Energy consumption modeling of air source electric heat pump water heaters

International Nuclear Information System (INIS)

Bourke, Grant; Bansal, Pradeep

2010-01-01

Electric heat pump air source water heaters may provide an opportunity for significant improvements in residential water heater energy efficiency in countries with temperate climates. As the performance of these appliances can vary widely, it is important for consumers to be able to accurately assess product performance in their application to maximise energy savings and ensure uptake of this technology. For a given ambient temperature and humidity, the performance of an air source heat pump water heater is strongly correlated to the water temperature in or surrounding the condenser. It is therefore important that energy consumption models for these products duplicate the real-world water temperatures applied to the heat pump condenser. This paper examines a recently published joint Australian and New Zealand Standard, AS/NZS 4234: 2008; Heated water systems - Calculation of energy consumption. Using this standard a series TRNSYS models were run for several split type air source electric heat pump water heaters. An equivalent set of models was then run utilizing an alternative water use pattern. Unfavorable errors of up to 12% were shown to occur in modeling of heat pump water heater performance using the current standard compared to the alternative regime. The difference in performance of a model using varying water use regimes can be greater than the performance difference between models of product.

Testing of nuclear air-cleaning systems

International Nuclear Information System (INIS)

Anon.

1975-01-01

A standard is presented which describes methods for field-testing nuclear power plant air cleaning systems. Included are specifications for visual inspection; duct and housing leak test; mounting frame pressure leak test; airflow capacity, distribution, and residence time tests; air-aerosol mixing uniformity test; in place leak test of HEPA filter banks; multiple sampling technique; in-place leak test of adsorber stage; laboratory testing of adsorbent; and duct heater performance test

Collecting performance of an evacuated tubular solar high-temperature air heater with concentric tube heat exchanger

International Nuclear Information System (INIS)

Wang, Ping-Yang; Li, Shuang-Fei; Liu, Zhen-Hua

2015-01-01

Highlights: • A novel evacuated tube solar high temperature air heater is designed. • The solar air heater system consists of 30 linked collecting units. • Every unit consisted of a evacuated tube, a simplified CPC and concentric tube. • The flow air is heated over temperature of 200 °C. - Abstract: A set of evacuated tube solar high temperature air heaters with simplified CPC (compound parabolic concentrator) and concentric tube heat exchanger is designed to provide flow air with a temperature of 150–230 °C for industrial production. The solar air heater system consists of 30 linked collecting units. Each unit includes a simplified CPC and an all-glass evacuated tube absorber with a concentric copper tube heat exchanger installed inside. A stainless steel mesh layer with high thermal conductivity is filled between the evacuated tube and the concentric copper tube. Air passes through each collecting unit, and its temperature increases progressively. An experimental investigation of the thermal performance of the air heater is performed, and the experimental results demonstrate the presented high-temperature solar air heater has excellent collecting performance and large output power, even in the winter. The measured thermal efficiency corresponding to the air temperature of 70 °C reaches 0.52. With the increase of air temperature, thermal efficiency reaches 0.35 at an air temperature of 150 °C, and 0.21 at an air temperature of 220 °C.

Thermo-hydraulic performance enhancement of solar air heater ...

African Journals Online (AJOL)

DR OKE

Keywords: Solar air heater; Nusselt number; thermal efficiency; multiple arcs with ... loss; and one or two covers of glass or transparent plastic provide resistance to ..... Methods of testing to determine the thermal performance of solar collectors.

Vacuum exhaust duct used for thermonuclear device

International Nuclear Information System (INIS)

Tachikawa, Nobuo; Kondo, Mitsuaki; Honda, Tsutomu.

1990-01-01

The present invention concerns a vacuum exhaust duct used for a thermonuclear device. A cylindrical metal liners is lined with a gap to the inside of a vacuum exhaust duct main body. Bellows are connected to both ends of the metal liners and the end of the bellows is welded to the vacuum exhaust duct main body. Futher, a heater is mounted to the metal liner on the side of the vacuum exhaust duct main body, and the metal liner is heated by the heater to conduct baking for the vacuum exhaust duct main body. Accordingly, since there is no requirement for elevating the temperature of the vacuum exhaust duct upon conducting baking, the vacuum exhaust duct scarcely suffers substantial deformation due to heat expansion. Further, there is also no substantial deformation for the bellows disposed between the outer circumference of the vacuum vessel and a portion of a vacuum exhaust duct, so that the durability of the bellows is greatly improved. (I.S.)

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

International Nuclear Information System (INIS)

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

2014-01-01

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

CREATION OF OPTIMIZATION MODEL OF STEAM BOILER RECUPERATIVE AIR HEATER

Directory of Open Access Journals (Sweden)

N. B. Carnickiy

2006-01-01

Full Text Available The paper proposes to use a mathematical modeling as one of the ways intended to improve quality of recuperative air heater design (RAH without significant additional costs, connected with the change of design materials or fuel type. The described conceptual mathematical AHP optimization model of RAH consists of optimized and constant parameters, technical limitations and optimality criteria.The paper considers a methodology for search of design and regime parameters of an air heater which is based on the methods of multi-criteria optimization. Conclusions for expediency of the given approach usage are made in the paper.

STUDY ON THE OPTIMIZATION OF IGBT THERMAL MANAGEMENT FOR PTC HEATER

Directory of Open Access Journals (Sweden)

J. W. JEONG

2015-12-01

Full Text Available It is essential to optimize HVAC (Heating, Ventilation and Air-Conditioning system for a thermal plant or an electric vehicle since it has a significant effect on the thermal efficiency. PTC (positive temperature coefficient heaters are often used for a heating system and the power module of the PTC heaters, IGBT (insulated gate bipolar mode transistor, requires thermal management. In this study, in order to maximize the cooling performance for IGBT, a novel method that uses forced convection inside the HVAC duct with heat sinks was developed. In addition, heat sinks were optimized in terms of IGBT junction temperature and heat sink weight by 3-dimensional CFD (Computational Fluid Dynamics simulation. The results show that the junction temperature of IGBT for 5.6kW PTC heater can be maintained at about 335K.

Advanced Strategy Guideline: Air Distribution Basics and Duct Design

Energy Technology Data Exchange (ETDEWEB)

Burdick, A.

2011-12-01

This report discusses considerations for designing an air distribution system for an energy efficient house that requires less air volume to condition the space. Considering the HVAC system early in the design process will allow adequate space for equipment and ductwork and can result in cost savings. Principles discussed that will maximize occupant comfort include delivery of the proper amount of conditioned air for appropriate temperature mixing and uniformity without drafts, minimization of system noise, the impacts of pressure loss, efficient return air duct design, and supply air outlet placement, as well as duct layout, materials, and sizing.

Experimental investigation on the performance of an impinging jet solar air heater

Directory of Open Access Journals (Sweden)

T. Rajaseenivasan

2017-03-01

Full Text Available Investigation on an impinging jet solar air heater is performed and reported in this work. The air is supplied through an impinging jet pipe which contains the nozzles to distribute the air in the solar air heater. The air is released from the jet strikes the absorber plate which increases the heat transfer rate by creating turbulent flow in the collector. This study is focused on the parameters that affect the heat transfer characteristics and compared with conventional solar air heater. The system is examined by varying the angle of attack (0°, 10°, 20°, 30°, 60° and 90° and the nozzle diameter (3 mm, 5 mm and 7 mm in the air mass flow rate range of 0.012–0.016 kg/s. The study revealed that the highest performance is achieved with the 30° angle of attack, and the lowest performance is recorded with the 0°. The reduction in jet diameter increases the pressure loss in the collector. The better system performance is observed with the 5 mm diameter hole. The maximum thermal enhancement factor of 2.19 and efficiency of 55.8% are reached with the flow rate of 0.016 kg/s.

Performance of a new solar air heater with packed-bed latent storage energy for nocturnal use

International Nuclear Information System (INIS)

Bouadila, Salwa; Kooli, Sami; Lazaar, Mariem; Skouri, Safa; Farhat, Abdelhamid

2013-01-01

Highlights: • A new solar air heater collector using a phase change material. • Experimental study of the new solar air heater collector with latent storage. • Energy and exergy analysis of the solar heater with latent storage collector. • Nocturnal use of solar air heater collector. - Abstract: An experimental study was conducted to evaluate the thermal performance of a new solar air heater collector using a packed bed of spherical capsules with a latent heat storage system. Using both first and second law of thermodynamics, the energetic and exegetic daily efficiencies were calculated in Closed/Opened and Opened cycle mode. The solar energy was stored in the packed bed through the diurnal period and extracted at night. The experimentally obtained results are used to analyze the performance of the system, based on temperature distribution in different localization of the collectors. The daily energy efficiency varied between 32% and 45%. While the daily exergy efficiency varied between 13% and 25%

Design of Solar Heat Sheet for Air Heaters

Science.gov (United States)

Priya, S. Shanmuga; Premalatha, M.; Thirunavukkarasu, I.

2011-12-01

The technique of harnessing solar energy for drying offers significant potential to dry agricultural products such as food grains, fruits, vegetables and medicinal plants, thereby eliminating many of the problems experienced with open-sun drying and industrial drying, besides saving huge quantities of fossil fuels. A great deal of experimental work over the last few decades has already demonstrated that agricultural products can be satisfactorily dehydrated using solar energy. Various designs of small scale solar dryers have been developed in the recent past, mainly for drying agricultural products. Major problems experienced with solar dryers are their non-reliability as their operation largely depends on local weather conditions. While back-up heaters and hybrid dryers partly solved this issue, difficulties in controlling the drying air temperature and flow rate remains a problem, and affects the quality of the dried product. This study is aimed at eliminating the fluctuations in the quality of hot air supplied by simple solar air heaters used for drying fruits, vegetables and other applications. It is an attempt to analyse the applicability of the combination of an glazed transpired solar collector (tank), thermal storage and a intake fan(suction fan) to achieve a steady supply of air at a different atmospheric temperature and flow rate for drying fruits and vegetables. Development of an efficient, low-cost and reliable air heating system for drying applications is done.

Consistent approach to air-cleaning system duct design

International Nuclear Information System (INIS)

Miller, W.H.; Ornberg, S.C.; Rooney, K.L.

1981-01-01

Nuclear power plant air-cleaning system effectiveness is dependent on the capability of a duct system to safely convey contaminated gas to a filtration unit and subsequently to a point of discharge. This paper presents a logical and consistent design approach for selecting sheet metal ductwork construction to meet applicable criteria. The differences in design engineers' duct construction specifications are acknowledged. Typical duct construction details and suggestions for their effective use are presented. Improvements in duct design sections of ANSI/ASME N509-80 are highlighted. A detailed leakage analysis of a control room HVAC system is undertaken to illustrate the effects of conceptual design variations on duct construction requirements. Shortcomings of previously published analyses and interpretations of a current standard are included

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

Science.gov (United States)

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

2008-03-01

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

The Energy Efficiency of Hot Water Production by Gas Water Heaters with a Combustion Chamber Sealed with Respect to the Room

Directory of Open Access Journals (Sweden)

Grzegorz Czerski

2014-08-01

Full Text Available This paper presents investigative results of the energy efficiency of hot water production for sanitary uses by means of gas-fired water heaters with the combustion chamber sealed with respect to the room in single-family houses and multi-story buildings. Additionally, calculations were made of the influence of pre-heating the air for combustion in the chimney and air supply system on the energy efficiency of hot water production. CFD (Computational Fluid Dynamics software was used for calculation of the heat exchange in this kind of system. The studies and calculations have shown that the use of gas water heaters with a combustion chamber sealed with respect to the room significantly increases the efficiency of hot water production when compared to traditional heaters. It has also been proven that the pre-heating of combustion air in concentric chimney and air supply ducts essentially improves the energy efficiency of gas appliances for hot water production.

Energy and exergy analysis of a new flat-plate solar air heater having different obstacles on absorber plates

International Nuclear Information System (INIS)

Akpinar, Ebru Kavak; Kocyigit, Fatih

2010-01-01

This study experimentally investigates performance analysis of a new flat-plate solar air heater (SAH) with several obstacles (Type I, Type II, Type III) and without obstacles (Type IV). Experiments were performed for two air mass flow rates of 0.0074 and 0.0052 kg/s. The first and second laws of efficiencies were determined for SAHs and comparisons were made among them. The values of first law efficiency varied between 20% and 82%. The values of second law efficiency changed from 8.32% to 44.00%. The highest efficiency were determined for the SAH with Type II absorbent plate in flow channel duct for all operating conditions, whereas the lowest values were obtained for the SAH without obstacles (Type IV). The results showed that the efficiency of the solar air collectors depends significantly on the solar radiation, surface geometry of the collectors and extension of the air flow line. The largest irreversibility was occurring at the SAH without obstacles (Type IV) collector in which collector efficiency is smallest. At the end of this study, the energy and exergy relationships are delivered for different SAHs.

The effect of inlet conditions on the air side hydraulic resistance and flow maldistribution in industrial air heaters

Energy Technology Data Exchange (ETDEWEB)

Hoffmann-Vocke, Jonas, E-mail: jh63@waikato.ac.nz [University of Waikato, Energy Research Group, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand); Neale, James, E-mail: jamesn@waikato.ac.nz [University of Waikato, Energy Research Group, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand); Walmsley, Michael, E-mail: walmsley@waikato.ac.nz [University of Waikato, Department of Engineering, School of Science and Engineering, Private Bag 3105, Hamilton 3240 (New Zealand)

2011-08-15

Highlights: > Measured the effects of air heater inlet header geometry on hydraulic performance. > Measured the effects of inlet header flow maldistribution on hydraulic performance. > Inlet header flow maldistribution increases air heater system hydraulic resistance. - Abstract: Experimental system hydraulic resistance measurements on a scale air heater unit have highlighted the excessive hydraulic resistance of typical industry configurations. Both poor header inlet conditions and large header expansion angles are shown to contribute to system hydraulic resistance magnitudes 20-100% higher than suitable benchmark cases. Typical centrifugal fan system efficiencies well under 80% multiply the system resistance effects resulting in larger fan power penalties. Velocity profile measurements taken upstream and downstream of the test heat exchanger under flow maldistribution conditions provide insight into the flow maldistribution spreading caused by the heat exchanger resistance. The anisotropic resistance of the plate fin-and-tube heat exchanger is shown to result in resistance induced flow dispersion being concentrated in the axis parallel to the plate fins.

The effect of inlet conditions on the air side hydraulic resistance and flow maldistribution in industrial air heaters

International Nuclear Information System (INIS)

Hoffmann-Vocke, Jonas; Neale, James; Walmsley, Michael

2011-01-01

Highlights: → Measured the effects of air heater inlet header geometry on hydraulic performance. → Measured the effects of inlet header flow maldistribution on hydraulic performance. → Inlet header flow maldistribution increases air heater system hydraulic resistance. - Abstract: Experimental system hydraulic resistance measurements on a scale air heater unit have highlighted the excessive hydraulic resistance of typical industry configurations. Both poor header inlet conditions and large header expansion angles are shown to contribute to system hydraulic resistance magnitudes 20-100% higher than suitable benchmark cases. Typical centrifugal fan system efficiencies well under 80% multiply the system resistance effects resulting in larger fan power penalties. Velocity profile measurements taken upstream and downstream of the test heat exchanger under flow maldistribution conditions provide insight into the flow maldistribution spreading caused by the heat exchanger resistance. The anisotropic resistance of the plate fin-and-tube heat exchanger is shown to result in resistance induced flow dispersion being concentrated in the axis parallel to the plate fins.

Modeling of a split type air conditioner with integrated water heater

International Nuclear Information System (INIS)

Techarungpaisan, P.; Theerakulpisut, S.; Priprem, S.

2007-01-01

This paper presents a steady state simulation model to predict the performance of a small split type air conditioner with integrated water heater. The mathematical model consists of submodels of system components such as evaporator, condenser, compressor, capillary tube, receiver and water heater. These submodels were built based on fundamental principles of heat transfer, thermodynamics, fluid mechanics, empirical relationships and manufacturer's data as necessary. The model was coded into a simulation program and used to predict system parameters of interest such as hot water temperature, condenser exit air temperature, evaporator exit air temperature, mass flow rate of refrigerant, heat rejection in the condenser and cooling capacity of the system. The simulation results were compared with experimental data obtained from an experimental rig built for validating the mathematical model. It was found that the experimental and simulation results are in good agreement

Analytical and Experimental Study of Recycling Baffled Double-Pass Solar Air Heaters with Attached Fins

Directory of Open Access Journals (Sweden)

Chun Sheng Lin

2013-03-01

Full Text Available The study of the heat transfer of solar air heaters with a new design using an absorbing plate with fins and baffles, which facilitate the recycling of flowing air, is reported. The mathematical formulation and analytical analysis for such a recyclic baffled double-pass solar air heater were developed theoretically. The performance of the device was studied experimentally as well. The theoretical predicted and experimental results were compared with another design, i.e., a downward-type single-pass solar air heater without recycle and double-pass operations reported in our previous work. Significant improvement in heat-transfer efficiency is achieved with the baffle and fin design due to the recycling heating and the extended heat transfer area. The effects of mass flow rate and recycle ratio on the heat-transfer efficiency enhancement as well as on the power consumption increment are also discussed.

Instrumentation strategies for energy conservation in broiler barns with ventilation air solar pre-heaters

Energy Technology Data Exchange (ETDEWEB)

Cordeau, Sebastien; Barrington, Suzelle [Department of Bioresource Engineering, Macdonald Campus of McGill University, 21 111 Lakeshore, Ste Anne de Bellevue, Quebec H9X 3V9 (Canada)

2010-08-15

At the present consumption rate, world fossil-fuel reserves are expected to be depleted by 2050 unless their consumption is optimized and supplemented with renewable energy sources. The objective of this project was to evaluate the performance of a simple data acquisition system installed to conduct an energy balance and identify energy saving strategies in two commercial broilers barns with ventilation air solar pre-heaters. Located near Montreal, Canada, the two identical barns were instrumented for inside and outside air conditions, ventilation rate and energy recovery by the solar air pre-heaters. Whereas the temperature, relative humidity and radiation sensors were reliable, inside air temperature stratification complicated energy balance analyses and broiler heat production rate calculations. Lack of room air mixing resulted in the loss of 25 and 15% of the generated heater load and recovered solar energy. The proper monitoring of all environmental conditions required their measurement every 5 rather than 20 min. Instead of using a data transmission service found to be unreliable in rural areas, all data loggers were downloaded onto a portable computer every 45 days during regular instrument maintenance. Accordingly, room air mixing is recommended to facilitate energy balance studies and improve the efficient use of heating energies. (author)

Whole house particle removal and clean air delivery rates for in-duct and portable ventilation systems.

Science.gov (United States)

Macintosh, David L; Myatt, Theodore A; Ludwig, Jerry F; Baker, Brian J; Suh, Helen H; Spengler, John D

2008-11-01

A novel method for determining whole house particle removal and clean air delivery rates attributable to central and portable ventilation/air cleaning systems is described. The method is used to characterize total and air-cleaner-specific particle removal rates during operation of four in-duct air cleaners and two portable air-cleaning devices in a fully instrumented test home. Operation of in-duct and portable air cleaners typically increased particle removal rates over the baseline rates determined in the absence of operating a central fan or an indoor air cleaner. Removal rates of 0.3- to 0.5-microm particles ranged from 1.5 hr(-1) during operation of an in-duct, 5-in. pleated media filter to 7.2 hr(-1) for an in-duct electrostatic air cleaner in comparison to a baseline rate of 0 hr(-1) when the air handler was operating without a filter. Removal rates for total particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5) mass concentrations were 0.5 hr(-1) under baseline conditions, 0.5 hr(-1) during operation of three portable ionic air cleaners, 1 hr(-1) for an in-duct 1-in. media filter, 2.4 hr(-1) for a single high-efficiency particle arrestance (HEPA) portable air cleaner, 4.6 hr(-1) for an in-duct 5-in. media filter, 4.7 hr(-1) during operation of five portable HEPA filters, 6.1 hr(-1) for a conventional in-duct electronic air cleaner, and 7.5 hr(-1) for a high efficiency in-duct electrostatic air cleaner. Corresponding whole house clean air delivery rates for PM2.5 attributable to the air cleaner independent of losses within the central ventilation system ranged from 2 m3/min for the conventional media filter to 32 m3/min for the high efficiency in-duct electrostatic device. Except for the portable ionic air cleaner, the devices considered here increased particle removal indoors over baseline deposition rates.

Vibroacoustic Analysis of a Refrigerator Freezer Cabinet Coupled with an Air Duct

Directory of Open Access Journals (Sweden)

Onur Çelikkan

2017-01-01

Full Text Available In this study, the vibration and acoustic interactions between the structure and the cavity inside the freezer cabinet were investigated. Thus, a set of numerical and experimental analyses were performed. In the numerical analysis, the acoustic characteristics of the freezer cavity were solved, and the mixed finite element method was then implemented to analyse the coupled behaviour of the cavity with the air duct using the Acoustic Fluid-Structure Interaction (AFSI technique. In the experimental analyses, an acoustic modal analysis of the freezer cavity and a structural modal analysis of the air duct were performed for the validation process. A good agreement was obtained among the results. Thus, the accuracy of the numerical model was confirmed. The validated models were used for optimizing the design. To solve the noise generation mechanism inside the freezer cabinet, the noise primarily generated by the freezer fan unit was measured under normal working conditions of the refrigerator, and the resonance frequencies were obtained. This information was compared with the normal modes of the air duct, and the overlapping frequencies were identified. To reduce the interaction between the source and the structure, a few design modifications were applied to the air duct. Thus, the structural-borne noise radiating from the air duct into the freezer cavity was reduced.

Quasi-steady state thermal performance of a solar air heater

African Journals Online (AJOL)

2017-01-17

Jan 17, 2017 ... two kind of solar air heaters are commonly used relates ...... step is then initialized with output temperature of the first ..... Where da is the diameter of the aluminum wire making the porous absorber mesh (da 0.45mm) and Dh ...

Research and development of an air-cycle heat-pump water heater. Final report

Energy Technology Data Exchange (ETDEWEB)

Dieckmann, J.T.; Erickson, A.J.; Harvey, A.C.; Toscano, W.M.

1979-10-01

A prototype reverse Brayton air cycle heat pump water heater has been designed and built for residential applications. The system consists of a compressor/expander, an air-water heat exchanger, an electric motor, a water circulation pump, a thermostat, and fluid management controls. The prototype development program consisted of a market analysis, design study, and development testing. A potential residential market for the new high-efficiency water heater of approximately 480,000 units/y was identified. The retail and installation cost of this water heater is estimated to be between $500 and $600 which is approximately $300 more than a conventional electric water heater. The average payback per unit is less than 3-1/2 y and the average recurring energy cost savings after the payback period is approximately $105/y at the average seasonal coefficient of performance (COP) of 1.7. As part of the design effort, a thermodynamic parametric analysis was performed on the water heater system. It was determined that to obtain a coefficient of performance of 1.7, the isentropic efficiency of both the compressor and the expander must be at least 85%. The selected mechanical configuration is described. The water heater has a diameter of 25 in. and a height of 73 in. The results of the development testing of the prototype water heater system showed: the electrical motor maximum efficiency of 78%; the compressor isentropic efficiency is 95 to 119% and the volumetric efficiency is approximately 85%; the expander isentropic efficiency is approximately 58% and the volumetric efficiency is 92%; a significant heat transfer loss of approximately 16% occurred in the expander; and the prototype heat pump system COP is 1.26 which is less than the design goal of at least 1.7. Future development work is recommended.

Practical use of CFD for air conditioning duct and defroster designing; Kucho duct defroster no CFD sekkei katsuyo

Energy Technology Data Exchange (ETDEWEB)

Okumura, K [Daihatsu Motor Co. Ltd., Osaka (Japan)

1997-10-01

The automobile industry have made effort to shorten the development period. Recently CFD (Computational Fluid Dynamics) on initial design stage becomes use for improvement of development efficiency. Although the practical guidepost (computed examples) for air conditioning duct and defroster are a little reported. This report presents how to optimize and standardize the calculational methods, calculational grid, boundary conditions for air conditioning duct and defroster nozzle in the practical use. Also we tried the discontinuous interface grid and the solution adaptive method. 2 refs., 17 figs.

Fire-tube immersion heater optimization program and field heater audit program

Energy Technology Data Exchange (ETDEWEB)

Croteau, P. [Petro-Canada, Calgary, AB (Canada)

2007-07-01

This presentation provided an overview of the top 5 priorities for emission reduction and eco-efficiency by the Petroleum Technology Alliance of Canada (PTAC). These included venting of methane emissions; fuel consumption in reciprocating engines; fuel consumption in fired heaters; flaring and incineration; and fugitive emissions. It described the common concern for many upstream operating companies as being energy consumption associated with immersion heaters. PTAC fire-tube heater and line heater studies were presented. Combustion efficiency was discussed in terms of excess air, fire-tube selection, heat flux rate, and reliability guidelines. Other topics included heat transfer and fire-tube design; burner selection; burner duty cycle; heater tune up inspection procedure; and insulation. Two other programs were also discussed, notably a Petro-Canada fire-tube immersion heater optimization program and the field audit program run by Natural Resources Canada. It was concluded that improved efficiency involves training; managing excess air in combustion; managing the burner duty cycle; striving for 82 per cent combustion efficiency; and providing adequate insulation to reduce energy demand. tabs., figs.

Energy and exergy analysis of a two pass photovoltaic –thermal (PV/T) air heater

Energy Technology Data Exchange (ETDEWEB)

Srinivas, M.; Jayaraj, S. [Department of Mechanical Engineering, National Institute of Technology, Calicut-673601 (India)

2013-07-01

A double pass hybrid solar air (PV/T) heater with slats is designed and fabricated to study elaborately its thermal and electrical performance corresponding to the warm and humid environment. Air as a heat removing fluid is made to flow through upper and lower channels of the collector. The collector is designed in such way that the absorber plate is partially covered by solar cells. Thin metallic strips (called slats) are attached longitudinally at the bottom side of the absorber plate to improve the overall system performance (by increasing the cooling rate of the absorber plate). Thermal and electrical performances of the whole system at different cooling rates are presented. The exergy analysis of double pass hybrid solar air (PV/T) heater with slats has also been carried out. The instantaneous overall energy and overall exergy efficiency of the double pass hybrid (PV/T) solar air heater varies between 29 – 37 percent and 14-17 percent respectively. These obtained values are comparable with that of published results.

Performances of packed bed double pass solar air heater with different inclinations and transverse wire mesh with different intervals

Directory of Open Access Journals (Sweden)

Sugantharaj Gnanadurai Sam Stanley

2016-01-01

Full Text Available Solar air heating is a technology in which the solar energy from the sun is captured by an absorbing medium and used to heat the air flowing through the heater. In this study, thermal performance of a double pass solar air heater has been investigated experimentally at different conditions. The experiments were conducted with different inclinations of the collector, with and without wire mesh vertically fixed at the second pass in transverse direction and with different mass flow rates. The effect of air mass flow rate, wire mesh pitch and collector inclination on temperature rise and thermal efficiency have been studied. Results show that efficiency increases with mass flow rate. For the same mass flow rate, the thermal efficiency increases with the decrease in the wire mesh pitch. The maximum daily average efficiency of air heater was 79.8% at 0.025 kg/s mass flow rate, 10 cm wire mesh gap and 9º collector inclination facing south. The highest collector efficiency was observed in solar air heaters with 10 cm wire mesh gap.

Thermo-hydraulic performance of solar air heater having multiple v-shaped rib roughness on absorber plates

Directory of Open Access Journals (Sweden)

Dhananjay Kumar

2018-03-01

Full Text Available This paper presents the performance analysis of the effect of geometrical parameters having multiple v-shaped rib roughness on the airflow side of the absorber plates. Mathematical approach and solution procedure for the analysis of such a solar air heater has been developed theoretically and MATLAB code generated for the solution of the mathematical equations. The effect of parameters such as flow Reynolds number and Relative roughness height on the thermohydraulic performance have been examined and compared with the conventional flat plate solar air heater. A substantial improvement in thermal efficiency of roughened solar air heater as compared to smooth one due to appreciable enhancement in heat transfer coefficient. The enhancement in heat transfer coefficient is also accompanied by a considerable enhancement in pumping power requirement due to the increase in friction factor.

Experimental and Theoretical Investigation of Impinging Jet Ventilation at Different Cross Sectional Area of Supply Air Duct

Directory of Open Access Journals (Sweden)

Ala'a Abbas Mahdi

2018-03-01

Full Text Available  An experimental and computational analysis of temperature and velocity distribution in an office room have been studied. Office room of dimensions (3m x 1.75m x 3m with two cross sectional types of supply air duct in the experimental part and three different cross sectional types of supply air duct in the theoretical part is usual as a tested model. The RNG k-  turbulence model was employed to solve the governing equations numerically and validated by comparing the numerical results with experimental data. The impinging jet concept has been proposed as a new ventilation strategy for use in office and industrial buildings. The present work focuses on evaluating the performance of a new impinging jet ventilation. In a theoretical study three types of supply air duct are adopted which are square supply air duct (Type-I, semi-elliptic supply air duct (Type-II and rectangle supply air duct (Type-III for two cases of air outlet terminal height from room foot level, 0.14h (case-I & 0.1h (case-II. The third type (rectangle duct gives lowest effective and discomfort conditions when compared with the other two types. This study investigated a number of factors influencing draught discomfort and temperature stratification in an office environment equipped with impinging jet ventilation IJV. The factors considered to be: shape of the air supply device, supply airflow rate and supply air temperature. Acceptable Air Distribution Performance Index (ADPI, effective temperature, and ventilation efficiency obtained that the square cross sectional area of supply air duct at 0.1h (case-II height from foot level gives more acceptable indoor air quality and human thermal comfort when compared with the other types. Also, this type gives good air distribution system not only promotes a comfortable and healthy environment for occupants, but also contributes to energy conservation.

High temperature collecting performance of a new all-glass evacuated tubular solar air heater with U-shaped tube heat exchanger

International Nuclear Information System (INIS)

Wang, Pin-Yang; Guan, Hong-Yang; Liu, Zhen-Hua; Wang, Guo-San; Zhao, Feng; Xiao, Hong-Sheng

2014-01-01

Highlights: • A novel solar air heater with simplified CPC and U-type heat exchanger is designed and tested. • The system is made up of 10 linked collecting panels. • Simplified CPC has a much lower cost at the expense of slight efficiency loss. • The air heater can propose the heated air exceeding 200 °C with great air flow rate. - Abstract: Experiment and simulation are conducted on a new-type all-glass evacuated tubular solar air heater with simplified compound parabolic concentrator (CPC). The system is made up of 10 linked collecting panels and each panel includes a simplified CPC and an all-glass evacuated tube with a U-shaped copper tube heat exchanger installed inside. Air is gradually heated when passing through each U-shaped copper tube. The heat transfer model of the solar air heater is established and the outlet air temperature, the heat power and heat efficiency are calculated. Calculated and experimental results show that the present experimental system can provide the heated air exceeding 200 °C. The whole system has an outstanding high-temperature collecting performance and the present heat transfer model can meet the general requirements of engineering calculations

Experience with vertical down-fired, coal-fuelled, low emissions air heaters incorporating automatic ash removal

Energy Technology Data Exchange (ETDEWEB)

Keller, M.; Noble, R.K.; Keller, J. [Tulsa Combustion LLC, Tulsa, OK (United States)

2009-07-01

This paper discussed the conversion of a horizontally-oriented air heater system with a vertically-oriented pulverized coal-fuelled air heater system. The vertically-oriented heater was used for automatic de-ashing and avoiding the ash accumulation often seen in horizontally-oriented systems. The study showed that the use of the vertical system significantly reduced emissions of nitrous oxides (NO{sub x}), carbon monoxide (CO) and volatile organic compounds (VOCs). Slag and salt attacks on the refractory were also reduced. The vertical systems provided automatic ash removal and eliminated hot spots on the refractory. The potential for variations in composition was also reduced. It was concluded that the system's smaller footprint means that it can be used in retrofits and can be installed in small spaces. 12 figs.

Performance comparison of air-source heat pump water heater with different expansion devices

International Nuclear Information System (INIS)

Peng, Jing-Wei; Li, Hui; Zhang, Chun-Lu

2016-01-01

Highlights: • An air-source heat pump water heater model was developed and validated. • System performance with EEV, capillary tube or short tube orifice were compared. • Short tube orifice is more suitable for heat pump water heater than capillary tube. - Abstract: Air source heat pump water heater (ASHPWH) is designed to work under wide operating conditions. Therefore, both the system and components require higher reliability and stability than ordinary heat pump air-conditioning systems. In this paper, a quasi-steady-state system model of ASHPWH using electronic expansion valve (EEV), capillary tube or short tube orifice as expansion device is developed and validated by a prototype using R134a and scroll compressor, by which the system performance is evaluated and compared at varying water temperature and different ambient temperature. Flow characteristics of those three expansion devices in ASHPWH are comparatively analyzed. Results show that the EEV throttling system performs best. Compared with capillary tube, flow characteristics of short tube orifice are closer to that of EEV and therefore more suitable for ASHPWH. Reliability concern of liquid carryover to the compressor in the system using short tube orifice is investigated as well. Higher superheat or less system refrigerant charge could help mitigate the risk.

Device Performance Improvement of Double-Pass Wire Mesh Packed Solar Air Heaters under Recycling Operation Conditions

Directory of Open Access Journals (Sweden)

Chii-Dong Ho

2016-01-01

Full Text Available The improvement of device performance of a recycling solar air heater featuring a wire mesh packing was investigated experimentally and theoretically. The application of the wire mesh packing and recycle-effect concept to the present study were proposed aiming to strengthen the convective heat-transfer coefficient due to increased turbulence. Comparisons were made among different designs, including the single-pass, flat-plate double-pass and recycling double-pass wire mesh packed operations. The collector efficiency of the recycling double-pass wire mesh packed solar air heater was much higher than that of the other configurations for various recycle ratios and mass flow rates scenarios. The power consumption increment due to implementing wire mesh in solar air heaters was also discussed considering the economic feasibility. A fairly good agreement between theoretical predictions and experimental measurements was achieved with an analyzed error of 1.07%–9.32%.

UNDERGROUND AIR DUCT TO CONTROL RISING MOISTURE IN HISTORIC BUILDINGS: IMPROVED DESIGN AND ITS DRYING EFFICIENCY

Directory of Open Access Journals (Sweden)

Jiří Pazderka

2017-10-01

Full Text Available The underground air ducts along peripheral walls of a building are a remediation method, which principle is to enable an air flow along the moist building structure’s surface to allow a sufficient evaporation of moisture from the structure. This measure reduces the water transport (rising moisture into the higher parts of the wall where the high water content in masonry is undesirable. Presently, underground air ducts are designed as masonry structures, which durability in contact with ground moisture is limited. The article describes a new design of an underground air duct, which is based on specially shaped concrete blocks (without wet processes, because the blocks are completely precast. The air duct from concrete blocks is situated completely below the ground surface (exterior or below the floor (interior. Thanks to this, the system is invisible and does not disturb the authentic look of rehabilitated historic buildings. The efficiency of the air duct technical solution was verified by the results of tests (based on the measured moisture values conducted on a laboratory model. The experimental study showed that the moisture in the masonry equipped with the presented underground air duct had decreased considerably compared to the reference sample, namely by 43 % on average. The experimental study was numerically validated through numerical simulations performed with the program WUFI 2D.

Quasi-steady state thermal performances of a solar air heater with ...

African Journals Online (AJOL)

Quasi-steady state thermal performance of a solar air heater with a combined absorber is studied. The whole energy balance equations related to the system were articulated as a linear system of temperature equations. Solutions to this linear system were assessed from program based on an iterative process. The mean ...

Alternative for Summer Use of Solar Air Heaters in Existing Buildings

Directory of Open Access Journals (Sweden)

Sergio L. González-González

2017-07-01

Full Text Available Among solar thermal technologies for indoor heating, solar air heaters (SAH are appealing for implementation on existing buildings due to their simplicity, fewer risks related to the working fluid, and possible independence from the building structure. However, existing research work mainly focuses on winter use and still fails in providing effective solutions for yearly operation, which would enhance their interest. With the aim of analysing an alternative summer use, this work firstly characterises a double channel-single pass solar air collector through experimentation. From the obtained results, modelling and simulation tasks have been conducted to evaluate the possibilities of using hot air, provided by the SAH, while operating under summer conditions within a closed loop, to feed an air-to-water heat exchanger for domestic hot water (DHW production. The system is studied through simulation under two different configurations for a case study in Valladolid (Spain, during the period from May to September for different airflows in the closed loop. Results show that daily savings can vary from 27% to 85% among the different operating conditions; a configuration where make-up water is fed to the heat exchanger being preferable, with a dedicated water tank for the solar heated water storage of the minimum possible volume. The more favourable results for the harshest months highlight the interest of extending the use of the solar air heaters to the summer period.

Study on the natural convection heat transfer characteristics in the air duct

Energy Technology Data Exchange (ETDEWEB)

Kim, Y K; Lee, Y B; Choi, S K; Hwang, J S; Nam, H Y [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1998-12-31

Temperature distribution measurements in the mockup apparatus of reactor vessel were performed to determine the effective thermal conductivity of porous media with different geometry and to obtain the experimental data for the heat transfer processes by natural convection occurring in the air duct. The temperature distributions at four separated sections with different arrangements of porous media have different slopes according to the geometrical configuration. From the measured temperature distribution, effective thermal conductivity have been derived using the least square fitting method. The test at air duct was performed to the high heat removal at 3.4kW/m{sup 2} by the natural convection from the outer wall to the air. And also the temperature distributions in the sir duct agree well with the 1/7th power-law turbulent temperature distribution. The obtained heat transfer data have been compared with the Shin`s and Sieger`s correlations. 10 refs., 6 figs. (Author)

Study on the natural convection heat transfer characteristics in the air duct

Energy Technology Data Exchange (ETDEWEB)

Kim, Y. K.; Lee, Y. B.; Choi, S. K.; Hwang, J. S.; Nam, H. Y. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-12-31

Temperature distribution measurements in the mockup apparatus of reactor vessel were performed to determine the effective thermal conductivity of porous media with different geometry and to obtain the experimental data for the heat transfer processes by natural convection occurring in the air duct. The temperature distributions at four separated sections with different arrangements of porous media have different slopes according to the geometrical configuration. From the measured temperature distribution, effective thermal conductivity have been derived using the least square fitting method. The test at air duct was performed to the high heat removal at 3.4kW/m{sup 2} by the natural convection from the outer wall to the air. And also the temperature distributions in the sir duct agree well with the 1/7th power-law turbulent temperature distribution. The obtained heat transfer data have been compared with the Shin`s and Sieger`s correlations. 10 refs., 6 figs. (Author)

Comparison of the Standard of Air Leakage in Current Metal Duct Systems in the World

Science.gov (United States)

Di, Yuhui; Wang, Jiqian; Feng, Lu; Li, Xingwu; Hu, Chunlin; Shi, Junshe; Xu, Qingsong; Qiao, Leilei

2018-01-01

Based on the requirements of air leakage of metal ducts in Chinese design standards, technical measures and construction standards, this paper compares the development history, the classification of air pressure levels and the air tightness levels of air leakage standards of current Chinese and international metal ducts, sums up the differences, finds shortage by investigating the design and construction status and access to information, and makes recommendations, hoping to help the majority of engineering and technical personnel.

Thermal Performance of Solar Air Heater Having Absorber Plate with V-Down Discrete Rib Roughness for Space-Heating Applications

Directory of Open Access Journals (Sweden)

Rajendra Karwa

2013-01-01

Full Text Available The paper presents results of thermal performance analysis of a solar air heater with v-down discrete rib roughness on the air flow side of the absorber plate, which supplies heated air for space heating applications. The air heater operates in a closed loop mode with inlet air at a fixed temperature of 295 K from the conditional space. The ambient temperature varied from 278 K to 288 K corresponding to the winter season of Western Rajasthan, India. The results of the analysis are presented in the form of performance plots, which can be utilized by a designer for calculating desired air flow rate at different ambient temperature and solar insolation values.

Study on Gas Field Optimization Distribution with Parameters Adjustment of the Air Duct Outlet for Mechanized Heading Face in Coal Mine

Science.gov (United States)

Gong, Xiao-Yan; Zhang, Xin-Yi; Wu, Yue; Xia, Zhi-Xin; Li, Ying

2017-12-01

At present, as the increasingly drilling dimensions with cross-section expansion and distance prolong in coal mine, the situation of gas accumulation in mechanized heading face becomes severe. In this paper, optimization research of gas distribution was carried out by adjusting parameters of the air duct outlet, including angle, caliber and the front and rear distance of air duct outlet. Mechanized heading face of Ningtiaota coal mine was taken as the research object, simulated and analyzed the problems of original gas field, the reasonable parameters range of the air duct outlet was determined according to the allowable range of wind speed and the effect of gas dilution, the adjustment range of each parameter of the air duct outlet is preliminarily determined. Base on this, the distribution of gas field under different parameters adjustment of air duct outlet was simulated. The specific parameters under the different distance between the air duct outlet and the mechanized heading face were obtained, and a new method of optimizing the gas distribution by adjusting parameters of the air duct outlet was provided.

Performance analysis of a hybrid photovoltaic thermal solar air heater

International Nuclear Information System (INIS)

Othman, Mohd Yusof; Yatim, Baharudin; Abu Bakar, Mohd Nazari; Sopian, Kamaruzzaman

2006-01-01

A photovoltaic (PV/T) air heater is a collector that combines thermal and photovoltaic systems in one single hybrid generating unit. It generators both thermal and electrical energies simultaneously. A new design of a double-pass photovoltaic-thermal solar air collector with CPC and fins was successfully developed and fabricated at Universiti Kebangsaam Malaysia. This collector tested under actual environmental conditions to study its performance over a range of operating conditions. The test set-up, instrumentation and measurement are described further. It was found that the performance of the collector was in agreement with the theoretical prediction. Results of the outdoors test are presented and discussed(Author)

Low-temperature baseboard heaters with integrated air supply - An analytical and numerical investigation

Energy Technology Data Exchange (ETDEWEB)

Ploskic, Adnan; Holmberg, Sture [Fluid and Climate Technology, School of Architecture and Built Environment, KTH, Marinens vaeg 30, SE-13640 Handen, Stockholm (Sweden)

2011-01-15

The functioning of a hydronic baseboard heating system with integrated air supply was analyzed. The aim was to investigate thermal performance of the system when cold outdoor (ventilation) airflow was forced through the baseboard heater. The performance of the system was evaluated for different ventilation rates at typical outdoor temperatures during the Swedish winter season. Three different analytical models and Computational Fluid Dynamics (CFD) were used to predict the temperature rise of the airflow inside the baseboard heater. Good agreement between numerical (CFD) and analytical calculations was obtained. Calculations showed that it was fully possible to pre-heat the incoming airflow to the indoor temperature and to cover transmission losses, using 45 C supply water flow. The analytical calculations also showed that the airflow per supply opening in the baseboard heater needed to be limited to 7.0 l/s due to pressure losses inside the channel. At this ventilation rate, the integrated system with one air supply gave about 2.1 more heat output than a conventional baseboard heating system. CFD simulations also showed that the integrated system was capable of countering downdraught created by 2.0 m high glazed areas and a cold outdoor environment. Draught discomfort in the case with the conventional system was slightly above the recommended upper limit, but heat distribution across whole analyzed office space was uniform for both heating systems. It was concluded that low-temperature baseboard heating systems with integrated air supply can meet both international comfort requirements, and lead to energy savings in cold climates. (author)

Preventive maintenance plan of the air-conditioning duct using the ACM-sensor

International Nuclear Information System (INIS)

Fukuba, Kazushi; Ito, Takanobu; Kojima, Akiko; Tanji, Kazuhiro; Sato, Yuki

2013-01-01

Air-conditioning duct is difficult to predict the date to occur of corrosion such as affect the function. Therefore, the current conservation method is mostly corrective maintenance. Therefore, we used the test pieces of six types and ACM-sensor in order to solve the corrosion speed from corrosion environment and relationship of corrosion quantity of test pieces. In addition, was used the duct molded articles various in order to check the corrosion degree of when processed the duct. As a result, we were selected crust body constituting a duct and optimal combination of the flange by solve the corrosion speed of the test pieces various. Thus, it performs preventive disposal before to occur of corrosion such as affect the function by predicting the duct life from corrosion speed, and lead to stability and safe operating by appropriate maintenance of equipment. (author)

Design of a Mobile Robot for Air Ducts Exploration

Directory of Open Access Journals (Sweden)

Moses A. Koledoye

2017-10-01

Full Text Available This work presents the solutions adopted for the design and the implementation of an autonomous wheeled robot developed for the exploration and mapping of air ventilation ducts. The hardware is based on commercial off-the-shelf devices, including sensors, motors, processing devices and interfaces. The mechanical chassis was designed from scratch to meet a trade-off between small size and available volume to host the components. The software stack is based on the Robot Operating System (ROS. Special attention was dedicated to the design of the mobility strategy, which must take into account some constraints and issues that are specific to the considered application, such as the relatively small size of ducts, the need to detect and avoid possible holes on the floor of the duct and other unusual obstacles and the unavailability of external reference frameworks for localization. The main contribution of this paper lies in the design, implementation and experimentation of the overall system.

Particulate matter sensor with a heater

Science.gov (United States)

Hall, Matthew [Austin, TX

2011-08-16

An apparatus to detect particulate matter. The apparatus includes a sensor electrode, a shroud, and a heater. The electrode measures a chemical composition within an exhaust stream. The shroud surrounds at least a portion of the sensor electrode, exclusive of a distal end of the sensor electrode exposed to the exhaust stream. The shroud defines an air gap between the sensor electrode and the shroud and an opening toward the distal end of the sensor electrode. The heater is mounted relative to the sensor electrode. The heater burns off particulate matter in the air gap between the sensor electrode and the shroud.

Effectiveness of HVAC duct cleaning procedures in improving indoor air quality.

Science.gov (United States)

Ahmad, I; Tansel, B; Mitrani, J D

2001-12-01

Indoor air quality has become one of the most serious environmental concerns as an average person spends about 22 hr indoors on a daily basis. The study reported in this article, was conducted to determine the effectiveness of three commercial HVAC (Heating Ventilation Air Conditioning) duct cleaning processes in reducing the level of airborne particulate matter and viable bioaerosols. The three HVAC sanitation processes were: (1) Contact method (use of conventional vacuum cleaning of interior duct surfaces); (2) Air sweep method (use of compressed air to dislodging dirt and debris); (3) Rotary brush method (insertion of a rotary brush into the ductwork to agitate and dislodge the debris). Effectiveness of these sanitation processes was evaluated in terms of airborne particulate and viable bioaerosol concentrations in residential homes. Eight identical homes were selected in the same neighborhood. Two homes were cleaned using each procedure and two were used as controls. It was found that both particle count readings and bioaerosol concentrations were higher when cleaning was being performed than before or after cleaning, which suggests that dirt, debris and other pollutants may become airborne as a result of disturbances caused by the cleaning processes. Particle count readings at 0.3 micron size were found to have increased due to cigarette smoking. Particle counts at 1.0 micron size were reduced due to HVAC duct cleaning. Post-level bioaerosol concentrations, taken two days after cleaning, were found to be lower than the pre-level concentrations suggesting that the cleaning procedures were effective to some extent. Homes cleaned with the Air Sweep procedure showed the highest degree of reduction in bioaerosol concentration among the three procedures investigated.

Forecast of thermal-hydrological conditions and air injection test results of the single heater test at Yucca Mountain

International Nuclear Information System (INIS)

Birkholzer, J.T.; Tsang, Y.W.

1996-12-01

The heater in the Single Heater Test (SHT) in alcove 5 of the Exploratory Studies Facility (ESF) was turned on August 26, 1996. A large number of sensors are installed in the various instrumented boreholes to monitor the coupled thermal-hydrological-mechanical-chemical responses of the rock mass to the heat generated in the single heater. In this report the authors present the results of the modeling of both the heating and cooling phases of the Single Heater Test (SHT), with focus on the thermal-hydrological aspect of the coupled processes. Also in this report, the authors present simulations of air injection tests will be performed at different stages of the heating and cooling phase of the SHT

Exergetic performance evaluation of a single pass baffled solar air heater

International Nuclear Information System (INIS)

Sabzpooshani, M.; Mohammadi, K.; Khorasanizadeh, H.

2014-01-01

In this study, the exergetic performance of a baffled type solar air heater has been evaluated theoretically. A detailed parametric study was done to investigate the effect of variation of fin and baffle parameters, number of glass covers, bottom insulation thickness and inlet air temperature at different mass flow rates on the exergy efficiency. The results indicated that attaching fins and baffles at low mass flow rates can lead to noticeable enhancement of the exergy efficiency. The results revealed that the trend of variation of the energy and exergy efficiencies are not the same and the exergy efficiency is the chief criterion for performance evaluation. Increasing the baffles width, reducing the distance between baffles and increasing the number of fins are effective at low mass flow rates, but at high mass flow rates the inverse trend is observable, such that exergy efficiency reduces sharply. The results showed that exergy efficiency increases with increasing the solar radiation intensity. By adding the second glass cover the exergy efficiency enhances at low mass flow rates. Increasing the insulation thickness over an optimum value doesn't improve the exergy efficiency. Increasing the inlet air temperature increases the exergy efficiency especially at high mass flow rates. - Highlights: • We study the exergetic performance of an upward type baffled solar air heater. • The effect of several design parameters on the performance is investigated. • Exergetic performance is very sensitive to the variation of baffles parameters. • Adding fins and baffles and increasing their parameters are efficient at low m . . • At high m . increment of baffles parameters causes decline of the exergy efficiency

Simulation analysis on dynamic performance of a combined solar/air dual source heat pump water heater

International Nuclear Information System (INIS)

Deng, Weishi; Yu, Jianlin

2016-01-01

Highlights: • A modified direct expansion solar-assisted heat pump water heater is investigated. • An additional air source evaporator is used in parallel way in the M-DX-SHPWH system. • The M-DX-SHPWH system displays a higher performance at the low solar radiation. • Effects of solar radiation and air temperature on the performance are discussed. - Abstract: This paper investigated a combined solar/air dual source heat pump water heater system for domestic water heating application. In the dual source system, an additional air source evaporator is introduced in parallel way based on a conventional direct expansion solar-assisted heat pump water heaters (DX-SHPWH) system, which can improve the performance of the DX-SHPWH system at a low solar radiation. In the present study, a dynamic mathematical model based on zoned lump parameter approach is developed to simulate the performance of the system (i.e. a modified DX-SHPWH (M-DX-SHPWH) system). Using the model, the performance of M-DX-SHPWH system is evaluated and then compared with that of the conventional DX-SHPWH system. The simulation results show the M-DX-SHPWH system has a better performance than that of the conventional DX-SHPWH system. At a low solar radiation of 100 W/m"2, the heating time of the M-DX-SHPWH decreases by 19.8% compared to the DX-SHPWH when water temperature reaches 55 °C. Meanwhile, the COP on average increases by 14.1%. In addition, the refrigerant mass flow rate distribution in the air source evaporator and the solar collector of the system, the allocation between the air source evaporator and the solar collector areas and effects of solar radiation and ambient air temperature on the system performance are discussed.

Evaluation of mixing downstream of tees in duct systems with respect to single point representative air sampling.

Science.gov (United States)

Kim, Taehong; O'Neal, Dennis L; Ortiz, Carlos

2006-09-01

Air duct systems in nuclear facilities must be monitored with continuous sampling in case of an accidental release of airborne radionuclides. The purpose of this work is to identify the air sampling locations where the velocity and contaminant concentrations fall below the 20% coefficient of variation required by the American National Standards Institute/Health Physics Society N13.1-1999. Experiments of velocity and tracer gas concentration were conducted on a generic "T" mixing system which included combinations of three sub ducts, one main duct, and air velocities from 0.5 to 2 m s (100 to 400 fpm). The experimental results suggest that turbulent mixing provides the accepted velocity coefficients of variation after 6 hydraulic diameters downstream of the T-junction. About 95% of the cases achieved coefficients of variation below 10% by 6 hydraulic diameters. However, above a velocity ratio (velocity in the sub duct/velocity in the main duct) of 2, velocity profiles were uniform in a shorter distance downstream of the T-junction as the velocity ratio went up. For the tracer gas concentration, the distance needed for the coefficients of variation to drop 20% decreased with increasing velocity ratio due to the sub duct airflow momentum. The results may apply to other duct systems with similar geometries and, ultimately, be a basis for selecting a proper sampling location under the requirements of single point representative sampling.

MHD oxidant intermediate temperature ceramic heater study

Science.gov (United States)

Carlson, A. W.; Chait, I. L.; Saari, D. P.; Marksberry, C. L.

1981-09-01

The use of three types of directly fired ceramic heaters for preheating oxygen enriched air to an intermediate temperature of 1144K was investigated. The three types of ceramic heaters are: (1) a fixed bed, periodic flow ceramic brick regenerative heater; (2) a ceramic pebble regenerative heater. The heater design, performance and operating characteristics under conditions in which the particulate matter is not solidified are evaluated. A comparison and overall evaluation of the three types of ceramic heaters and temperature range determination at which the particulate matter in the MHD exhaust gas is estimated to be a dry powder are presented.

Infrared Heaters

Science.gov (United States)

1979-01-01

The heating units shown in the accompanying photos are Panelbloc infrared heaters, energy savers which burn little fuel in relation to their effective heat output. Produced by Bettcher Manufacturing Corporation, Cleveland, Ohio, Panelblocs are applicable to industrial or other facilities which have ceilings more than 12 feet high, such as those pictured: at left the Bare Hills Tennis Club, Baltimore, Maryland and at right, CVA Lincoln- Mercury, Gaithersburg, Maryland. The heaters are mounted high above the floor and they radiate infrared energy downward. Panelblocs do not waste energy by warming the surrounding air. Instead, they beam invisible heat rays directly to objects which absorb the radiation- people, floors, machinery and other plant equipment. All these objects in turn re-radiate the energy to the air. A key element in the Panelbloc design is a coating applied to the aluminized steel outer surface of the heater. This coating must be corrosion resistant at high temperatures and it must have high "emissivity"-the ability of a surface to emit radiant energy. The Bettcher company formerly used a porcelain coating, but it caused a production problem. Bettcher did not have the capability to apply the material in its own plant, so the heaters had to be shipped out of state for porcelainizing, which entailed extra cost. Bettcher sought a coating which could meet the specifications yet be applied in its own facilities. The company asked The Knowledge Availability Systems Center, Pittsburgh, Pennsylvania, a NASA Industrial Applications Center (IAC), for a search of NASA's files

A parametric study on a humidification–dehumidification (HDH) desalination unit powered by solar air and water heaters

International Nuclear Information System (INIS)

Yıldırım, Cihan; Solmuş, İsmail

2014-01-01

Highlights: • A time dependent humidification–dehumidification desalination process is investigated. • Fourth-order Runge–Kutta method is used to simulate the problem. • Daily and annual performance are examined. • Various operational parameters are investigated. - Abstract: The performance of a solar powered humidification–dehumidification desalination system is theoretically investigated for various operating and design parameters of the system under climatological conditions of Antalya, Turkey. The primary components of the system are a flat plate solar water heater, a flat plate double pass solar air heater, a humidifier, a dehumidifier and a storage tank. The mathematical model of the system is developed and governing conservation equations are numerically solved by using the Fourth order Runge–Kutta method. Daily and annual yields are calculated for different configurations of the system such as only water heating, only air heating and water–air heating

Analyses and Comparison of Solar Air Heater with Various Rib Roughness using Computational Fluid Dynamics (CFD)

Science.gov (United States)

Kumar, K. Ravi; Cheepu, Muralimohan; Srinivas, B.; Venkateswarlu, D.; Pramod Kumar, G.; Shiva, Apireddi

2018-03-01

In solar air heater, artificial roughness on absorber plate become prominent technique to improving heat transfer rate of air flowing passage as a result of laminar sublayer. The selection of rib geometries plays important role on friction characteristics and heat transfer rate. Many researchers studying the roughness shapes over the years to investigate the effect of geometries on the performance of friction factor and heat transfer of the solar air heater. The present study made an attempt to develop the different rib shapes utilised for creating artificial rib roughness and its comparison to investigate higher performance of the geometries. The use of computational fluid dynamics software resulted in correlation of friction factor and heat transfer rate. The simulations studies were performed on 2D computational fluid dynamics model and analysed to identify the most effective parameters of relative roughness of the height, width and pitch on major considerations of friction factor and heat transfer. The Reynolds number is varied in a range from 3000 to 20000, in the current study and modelling has conducted on heat transfer and turbulence phenomena by using Reynolds number. The modelling results showed the formation of strong vortex in the main stream flow due to the right angle triangle roughness over the square, rectangle, improved rectangle and equilateral triangle geometries enhanced the heat transfer extension in the solar air heater. The simulation of the turbulence kinetic energy of the geometry suggests the local turbulence kinetic energy has been influenced strongly by the alignments of the right angle triangle.

Should you get your heating ducts cleaned?

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

Canada Mortgage and Housing Corporation conducted research into duct cleaning during which time several houses were tested for hot air furnace duct performance before and after cleaning. Duct cleaning is a major industry which claims that cleaning of ducts will provide you with better indoor air quality, reduce household molds and allergens, get rid of house dust, result in more airflow and better delivery of warm air and reduce energy costs. This report does not substantiate those claims. Researchers found little or no discernible differences in the concentrations of house airborne particles or in duct airflows due to duct cleaning. This is because ducts are metal passages that cannot create dust. Most household dusts come from outdoors that has been tracked in or blows through windows and other openings. While duct cleaning may be justifiable personally, it does not change the quality of the air you breathe, nor will it significantly affect airflow or heating costs. Some filters effectively clean the air in the ducts but they do not create a dust-free environment because of the above-mentioned dust sources. The only time that duct cleaning may make sense is if you have water in your ducts that can result in mold growth, if you are moving into a newly constructed house to remove drywall dust, if your are having trouble with furnace airflow, or if you see an accumulation of debris in the return air ducts. It was emphasized that broadcast spraying of biocides within the duct system should not be performed.

High accuracy acoustic relative humidity measurement in duct flow with air

NARCIS (Netherlands)

Schaik, van W.; Grooten, M.H.M.; Wernaart, T.; Geld, van der C.W.M.

2010-01-01

An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and

Dual fan, dual-duct system meets air quality, energy-efficiency needs

Energy Technology Data Exchange (ETDEWEB)

Schuler, M. [Pageau Morel and Associates, Montreal, Quebec (Canada)

1996-03-01

Canada`s Space Centre in Saint-Hubert Quebec is a 300,000 ft{sup 2} (27,871 m{sup 2}) complex that houses the headquarters of the Canadian Space Agency, the Canadian Astronaut Training Centre, mission ground control installations, research facilities, offices and the required support facilities. A comfortable, pleasant research environment was a primary concern for the Space Centre, given its elite clientele. The objectives were high indoor-air quality, design flexibility, energy efficiency and low capital costs. Dual duct systems which are the heart of the mechanical concept allowed the designers to meet these objectives. The Space Centre`s offices, laboratories and conference center are all served by dual-duct systems. All operate using an air economizer cycle. Gas boilers provide them with hot water for heating and steam for humidification while centrifugal chillers provide chilled water for cooling. This article describes the design.

Air source heat pump water heater: Dynamic modeling, optimal energy management and mini-tubes condensers

International Nuclear Information System (INIS)

Ibrahim, Oussama; Fardoun, Farouk; Younes, Rafic; Louahlia-Gualous, Hasna

2014-01-01

This paper presents a dynamic simulation model to predict the performance of an ASHPWH (air source heat pump water heater). The developed model is used to assess its performance in the Lebanese context. It is shown that for the four Lebanese climatic zones, the expected monthly values of the average COP (coefficient of performance) varies from 2.9 to 5, leading to high efficiencies compared with conventional electric water heaters. The energy savings and GHG (greenhouse gas) emissions reduction are investigated for each zone. Furthermore, it is recommended to use the ASHPWH during the period of highest daily ambient temperatures (noon or afternoon), assuming that the electricity tariff and hot water loads are constant. In addition, an optimal management model for the ASHPWH is developed and applied for a typical winter day of Beirut. Moreover, the developed dynamic model of ASHPWH is used to compare the performance of three similar systems that differ only with the condenser geometry, where results show that using mini-condenser geometries increase the COP (coefficient of performance) and consequently, more energy is saved as well as more GHG emissions are reduced. In addition, the condenser “surface compactness” is increased giving rise to an efficient compact heat exchanger. - Highlights: • Numerical modeling and experimental validation for ASHPWH (air source heat pump water heater). • Optimization of the ASHPWH-condenser length. • Comparison of the ASHPWH with conventional electric water heater according to energy efficiency and green gas house emissions. • Development of an energetic-economic optimal management model for ASHPWH. • Energetic and environmental assessment of ASHPWH with mini-tubes condensers

Parametric simulation and experimental analysis of earth air heat exchanger with solar air heating duct

Directory of Open Access Journals (Sweden)

Sanjeev Jakhar

2016-06-01

Full Text Available Earth air heat exchanger (EAHE systems are insufficient to meet the thermal comfort requirements in winter conditions. The low heating potential of such systems can be improved by integrating the system with solar air heating duct (SAHD. The aim of this paper is to present a model to estimate the heating potential for EAHE system with and without SAHD. The model is generated using TRNSYS 17 simulation tool and validated against experimental investigation on an experimental set-up in Ajmer, India. The experiment was done during the winter season, where the system was evaluated for different inlet flow velocities, length and depth of buried pipe. From the experimentation, it was observed that the depth of 3.7 m is sufficient for pipe burial and the 34 m length of pipe is sufficient to get optimum EAHE outlet temperature. It is also observed that increase in flow velocity results in drop in EAHE outlet temperature, while room temperature is found to increase for higher velocities (5 m/s. The COP of the system also increased up to 6.304 when assisted with solar air heating duct. The results obtained from the experiment data are in good agreement with simulated results within the variation of up to 7.9%.

Modeling and Simulation of Turbulent Flows through a Solar Air Heater Having Square-Sectioned Transverse Rib Roughness on the Absorber Plate

Directory of Open Access Journals (Sweden)

Anil Singh Yadav

2013-01-01

Full Text Available Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. Use of artificial roughness on a surface is an effective technique to enhance the rate of heat transfer. A CFD-based investigation of turbulent flow through a solar air heater roughened with square-sectioned transverse rib roughness has been performed. Three different values of rib-pitch (P and rib-height (e have been taken such that the relative roughness pitch (P/e=14.29 remains constant. The relative roughness height, e/D, varies from 0.021 to 0.06, and the Reynolds number, Re, varies from 3800 to 18,000. The results predicted by CFD show that the average heat transfer, average flow friction, and thermohydraulic performance parameter are strongly dependent on the relative roughness height. A maximum value of thermohydraulic performance parameter has been found to be 1.8 for the range of parameters investigated. Comparisons with previously published work have been performed and found to be in excellent agreement.

Modeling and simulation of turbulent flows through a solar air heater having square-sectioned transverse rib roughness on the absorber plate.

Science.gov (United States)

Yadav, Anil Singh; Bhagoria, J L

2013-01-01

Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. Use of artificial roughness on a surface is an effective technique to enhance the rate of heat transfer. A CFD-based investigation of turbulent flow through a solar air heater roughened with square-sectioned transverse rib roughness has been performed. Three different values of rib-pitch (P) and rib-height (e) have been taken such that the relative roughness pitch (P/e = 14.29) remains constant. The relative roughness height, e/D, varies from 0.021 to 0.06, and the Reynolds number, Re, varies from 3800 to 18,000. The results predicted by CFD show that the average heat transfer, average flow friction, and thermohydraulic performance parameter are strongly dependent on the relative roughness height. A maximum value of thermohydraulic performance parameter has been found to be 1.8 for the range of parameters investigated. Comparisons with previously published work have been performed and found to be in excellent agreement.

ECOLO-HOUSE in the heavy snow-fall region. Study of the ventilating function that the heat collecting system of the air duct utilizing attic has; Yukiguni ECOLO-HOUSE. Kison kaoku no yaneura wo riyoshita duct shunetsu system kanki kino hyoka

Energy Technology Data Exchange (ETDEWEB)

Umemiya, H; Hirosawa, K [Yamagata University, Yamagata (Japan)

1997-11-25

This paper reports a duct heat collecting system installed in the ECOLO-HOUSE for snow countries. This system is an air heat collecting system of the outside air introducing type utilizing as a solar heat collector the single pitch roof often seen in snow countries. Outside air is introduced from below eaves into a heat collecting duct made by nailing plywoods onto rafters from the attic side to collect heat on the roof. Operating a sirocco fan connected to the induction duct located on the high-floor foundation sucks outside air from an air intake opening under the eaves into the heat collecting duct. Air which has absorbed heat on the roof and been warmed in the heat collecting duct by insolation goes into a heat collecting chamber. The air is sent into the high-floor foundation through the induction duct laid from the heat collecting chamber. Air is exchanged 8.7 times by the fan when it is operated all day continuously. Condensation in the fuel chamber floor and walls during the rainy season has disappeared, and so has odor at the same time. As a result of the humidity measurement, a location into which warm air is sent has difference in humidity as great as 15% from a location where no warm air is sent. 2 refs., 6 figs., 2 tabs.

Specific aspects of turbulent flow in rectangular ducts

Directory of Open Access Journals (Sweden)

Stanković Branislav D.

2017-01-01

Full Text Available The essential ideas of investigations of turbulent flow in a straight rectangular duct are chronologically presented. Fundamentally significant experimental and theoretical studies for mathematical modeling and numerical computations of this flow configuration are analyzed. An important physical aspect of this type of flow is presence of secondary motion in the plane perpendicular to the streamwise direction, which is of interest from both the engineering and the scientific viewpoints. The key facts for a task of turbulence modeling and optimal choice of the turbulence model are obtained through careful examination of physical mechanisms that generate secondary flows. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no.TR-33018: Increase in Energy and Ecology Efficiency of Processes in Pulverized Coal-Fired Furnace and Optimization of Utility Steam Boiler Air Pre-heater by Using In-House Developed Software Tools

Augmentation of Effective Thermal Gain of Solar Air Heater using a Novel Turbulator Design- A CFD Study

Directory of Open Access Journals (Sweden)

Dhagat Animesh

2018-01-01

Full Text Available Augmentation of thermal performance of solar air heater has been the focus of many researchers over the last decades and the use of turbulator or artificial roughness to provide increased fluid mixing in order to achieve augmented heat transfer has been a widely accepted technique. This work aims to evaluate the effect of a novel turbulator design on the effective thermal performance of solar air heater using the methodology of computational fluid dynamics (CFD. A two dimensional CFD analysis is carried out to evaluate the thermal characteristics of solar air heater at various flow Reynolds number conditions for different geometric parameters of the proposed turbulator design. The pitch of the turbulator is varied as 10mm, 20mm, 30mm, 40mm and 50mm for a fixed turbulator height of 2 mm. The Reynolds number is varied from 6,000 to 27,000. The analysis shows that the lower values of pitch produces higher improvement in heat transfer. The maximum increase in Nusselt number is found to be about 2.98 times as compared to the base model for the flow Reynolds number of about 6000. The highest increase in the friction factor is found to be about 3.05 times relative to the base model. The maximum thermal enhancement factor is found to be about 1.99 for the pitch value of 10 mm at a flow Reynolds number of about 6000.

HAARP-Induced Ionospheric Ducts

International Nuclear Information System (INIS)

Milikh, Gennady; Vartanyan, Aram

2011-01-01

It is well known that strong electron heating by a powerful HF-facility can lead to the formation of electron and ion density perturbations that stretch along the magnetic field line. Those density perturbations can serve as ducts for ELF waves, both of natural and artificial origin. This paper presents observations of the plasma density perturbations caused by the HF-heating of the ionosphere by the HAARP facility. The low orbit satellite DEMETER was used as a diagnostic tool to measure the electron and ion temperature and density along the satellite orbit overflying close to the magnetic zenith of the HF-heater. Those observations will be then checked against the theoretical model of duct formation due to HF-heating of the ionosphere. The model is based on the modified SAMI2 code, and is validated by comparison with well documented experiments.

Solar Water-Heater Design and Installation

Science.gov (United States)

Harlamert, P.; Kennard, J.; Ciriunas, J.

1982-01-01

Solar/Water heater system works as follows: Solar--heated air is pumped from collectors through rock bin from top to bottom. Air handler circulates heated air through an air-to-water heat exchanger, which transfers heat to incoming well water. In one application, it may reduce oil use by 40 percent.

Water condensation promotes fungal growth in ventilation ducts

Energy Technology Data Exchange (ETDEWEB)

Pasanen, P.; Pasanen, A.-L. (University of Kupopio, Department of Environmental Sciences, Kuopio (Finland)); Jantunen, M. (National Public Health Institute, Kuopio (Finland))

1993-01-01

In a subarctic climate the diurnal variation in temperature may cause water condensation in ducts placed in the unheated spaces of a building. In this study, germination time and sporulation of a fungus, Penicillium verrucosum, were studied on dusty, galvanized steel sheet under different moisture conditions at room temperature. The effect of condensed water in a supply air duct on spore amplification was studied in an experimental ventilation set-up. In the field, air temperatures and the dew point temperature of air in the duct were monitored continuously for a week. P. verrucosum germinated on steel surfaces during five-hour incubation of the surface under humid conditions, when the surface has been moist for half an hour, germ tubes appeared within 17 hours. During 24-hour incubation under moist conditions, P. verrucosum produced hyphae and spores. In the experimental set-up the airborne spore counts increased when the air passed through a water-condensing section of the duct. Penicillium was the most abundant fungus sporulated on the moist duct surface. In the field, during humid weather, the surface temperature on the air stream surface decreased to the dew point temperature of the air in the duct. thus water condensation in air ducts may promote fungal growth. (au)

The Transmission of Thermal and Fast Neutrons in Air Filled Annular Ducts through Slabs of Iron and Heavy Water

Energy Technology Data Exchange (ETDEWEB)

Nilsson, J; Sandlin, R

1964-12-15

An investigation has been carried out concerning the transmission of thermal and fast neutrons in air filled annular ducts through laminated Fe-D{sub 2}O shields. Measurements have been made with annular air gaps of 0.5, 1.0, 1.5 and 2.0 cm, at a duct length of half a meter. The neutron fluxes were determined with a foil activation technique. The thermal flux was theoretically and experimentally divided into three components, a streaming, a leakage and an albedo component. The fast flux was similarly divided into a streaming component and a 'leakage' component. A calculational model to predict the components was then developed and fitted, to the data obtained by experiments. The model reported here for prediction of neutron attenuation in ducted configurations may be applied to straight annular ducts of arbitrary dimensions and material configurations but is especially designed for the problems met with in short ducts.

A Plug-and-Play Duct System Evaluation

Energy Technology Data Exchange (ETDEWEB)

Beach, R. [IBACOS, Inc., Pittsburgh, PA (United States); Dickson, B. [IBACOS, Inc., Pittsburgh, PA (United States); Grisolia, A. [IBACOS, Inc., Pittsburgh, PA (United States); Poerschke, A. [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, A. [IBACOS, Inc., Pittsburgh, PA (United States)

2017-07-01

This report describes an air distribution system composed of a series of uniformly-sized ducts that terminate in rooms throughout the home and return to a central manifold, similar in fashion to a “home-run” cross-linked polyethylene plumbing system. With a well-designed manifold, each duct receives an equal static pressure potential for airflow from the air handling unit, and the number of needed ducts for each room are simply attached to fittings located on the manifold; in this sense, the system is plug-and-play (PnP). As indicated, all ducts in the PnP system are identical in size and small enough to fit in the ceiling and wall cavities of a house (i.e., less than 3.5-in. outer diameter). These ducts are also more appropriately sized for the lower airflow requirements of modern, energy-efficient homes; therefore, the velocity of the air moving through the duct is between that of conventional duct systems (approximately 700 ft/min) and high-velocity systems (more than 1,500 ft/min) on the market today. The PnP duct system uses semi-rigid plastic pipes, which have a smooth inner wall and are straightforward to install correctly, resulting in a system that has minimal air leakage. However, plastic ducts are currently not accepted by code for use in residential buildings; therefore, the project team considered other duct materials for the system that are currently accepted by code, such as small-diameter, wirehelix, flexible ductwork.

A Plug-and-Play Duct System Evaluation

Energy Technology Data Exchange (ETDEWEB)

Beach, Robert [IBACOS, Inc., Pittsburgh, PA (United States); Dickson, Bruce [IBACOS, Inc., Pittsburgh, PA (United States); Grisolia, Anthony [IBACOS, Inc., Pittsburgh, PA (United States); Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, Ari [IBACOS, Inc., Pittsburgh, PA (United States)

2017-07-10

This report describes an air distribution system composed of a series of uniformly-sized ducts that terminate in rooms throughout the home and return to a central manifold, similar in fashion to a “home-run” cross-linked polyethylene plumbing system. With a well-designed manifold, each duct receives an equal static pressure potential for airflow from the air handling unit, and the number of needed ducts for each room are simply attached to fittings located on the manifold; in this sense, the system is plug-and-play (PnP). As indicated, all ducts in the PnP system are identical in size and small enough to fit in the ceiling and wall cavities of a house (i.e., less than 3.5-in. outer diameter). These ducts are also more appropriately sized for the lower airflow requirements of modern, energy-efficient homes; therefore, the velocity of the air moving through the duct is between that of conventional duct systems (approximately 700 ft/min) and high-velocity systems (more than 1,500 ft/min) on the market today. The PnP duct system uses semi-rigid plastic pipes, which have a smooth inner wall and are straightforward to install correctly, resulting in a system that has minimal air leakage. However, plastic ducts are currently not accepted by code for use in residential buildings; therefore, the project team considered other duct materials for the system that are currently accepted by code, such as small-diameter, wirehelix, flexible ductwork.

Adiabatic packed column supercritical fluid chromatography using a dual-zone still-air column heater.

Science.gov (United States)

Helmueller, Shawn C; Poe, Donald P; Kaczmarski, Krzysztof

2018-02-02

An approach to conducting SFC separations under pseudo-adiabatic condition utilizing a dual-zone column heater is described. The heater allows for efficient separations at low pressures above the critical temperature by imposing a temperature profile along the column wall that closely matches that for isenthalpic expansion of the fluid inside the column. As a result, the efficiency loss associated with the formation of radial temperature gradients in this difficult region can be largely avoided in packed analytical scale columns. For elution of n-octadecylbenzene at 60 °C with 5% methanol modifier and a flow rate of 3 mL/min, a 250 × 4.6-mm column packed with 5-micron Kinetex C18 particles began to lose efficiency (8% decrease in the number of theoretical plates) at outlet pressures below 142 bar in a traditional forced air oven. The corresponding outlet pressure for onset of excess efficiency loss was decreased to 121 bar when the column was operated in a commercial HPLC column heater, and to 104 bar in the new dual-zone heater operated in adiabatic mode, with corresponding increases in the retention factor for n-octadecylbenzene from 2.9 to 6.8 and 14, respectively. This approach allows for increased retention and efficient separations of otherwise weakly retained analytes. Applications are described for rapid SFC separation of an alkylbenzene mixture using a pressure ramp, and isobaric separation of a cannabinoid mixture. Copyright © 2018 Elsevier B.V. All rights reserved.

Particle deposition in ventilation ducts

Energy Technology Data Exchange (ETDEWEB)

Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)

2002-09-01

Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 μm were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the

Heating, ventilating, and air conditioning deactivation thermal analysis of PUREX Plant

Energy Technology Data Exchange (ETDEWEB)

Chen, W.W.; Gregonis, R.A. [Westinghouse Hanford Company, Richland, WA (United States)

1997-08-01

Thermal analysis was performed for the proposed Plutonium Uranium Extraction Plant exhaust system after deactivation. The purpose of the analysis was to determine if enough condensation will occur to plug or damage the filtration components. A heat transfer and fluid flow analysis was performed to evaluate the thermal characteristics of the underground duct system, the deep-bed glass fiber filter No. 2, and the high-efficiency particulate air filters in the fourth filter building. The analysis is based on extreme variations of air temperature, relative humidity, and dew point temperature using 15 years of Hanford Site weather data as a basis. The results will be used to evaluate the need for the electric heaters proposed for the canyon exhaust to prevent condensation. Results of the analysis indicate that a condition may exist in the underground ductwork where the duct temperature can lead or lag changes in the ambient air temperature. This condition may contribute to condensation on the inside surfaces of the underground exhaust duct. A worst case conservative analysis was performed assuming that all of the water is removed from the moist air over the inside surface of the concrete duct area in the fully developed turbulent boundary layer while the moist air in the free stream will not condense. The total moisture accumulated in 24 hours is negligible. Water puddling would not be expected. The results of the analyses agree with plant operating experiences. The filters were designed to resist high humidity and direct wetting, filter plugging caused by slight condensation in the upstream duct is not a concern. 19 refs., 2 figs.

Correlations for heat transfer coefficient and friction factor for turbulent flow of air through square and hexagonal ducts with twisted tape insert

Science.gov (United States)

Yadav, Rupesh J.; Kore, Sandeep S.; Joshi, Prathamesh S.

2018-05-01

The experimental and numerical Nusselt number and friction factor investigation for turbulent flow through a non-circular duct with twisted-tape inserts have been presented. The non-circular ducts include square, hexagonal duct. The results of non-circular ducts are compared with circular duct. All the ducts have same equivalent diameter. The twist ratios used for the experiment are Y = 3.5, 4.5, 5.5 and 6.5. Experiments were carried out on square duct, hexagonal duct and circular duct. The Reynolds number lied between 10,000 and 1, 05,000. The present study is restricted to the flow of air at Pr = 0.7 only and within a narrow temperature range of 40 to 75 ΟC, within which the compressible nature of air can be neglected. The results reveal that, both Nusselt number and friction factor increases as the side of non-circular duct increases. Maximum Nusselt number and friction factor is obtained in case of circular duct with twisted tape. Further the correlations of Nu and f are given for different non circular duct with twisted tape insert for engineering applications for the turbulent regime. Since the thermal performance factor (η) is observed to be within the range of 0.8 to 1.13 for both circular and noncircular ducts, the overall benefit of using twisted tape in the flow field shall nevertheless be marginal.

Evaluation of Solar Air Heater Performance with Artificial Rib Roughness over the Absorber Plate using Finite Element Modelling Analysis

Science.gov (United States)

Kumar, K. Ravi; Nikhil Varma, P.; Jagadeesh, N.; Sandeep, J. V.; Cheepu, Muralimohan; Venkateswarlu, D.; Srinivas, B.

2018-03-01

Among the different renewable energy resources, solar energy is widely used due to its quantitative intensity factor. Solar air heater is cheap, simple in design and has got wide range of applications. A modest solar air heater has a lower in heat transfer and thermal performance as it has heat transfer coefficient lower in between coated absorber plate and the carrier fluid. This low thermal performance can be reduced to a greater extent by introducing the artificially created roughness over the absorber plate of the solar heater. In the present study, the combination of various geometries and roughness’s on the absorber plate are reported. Methods have been developed and implemented in order to improve the rate of the heat transfer. A comparison is drawn among different geometries to select the most effective absorber plate roughness. For flow analysis k-ω SST model was used and the constant heat flux was taken as 1100 W/m2. The Reynolds number is varied in a range from 3000 to 20000. The variation of different parameters temperature, Nusselt number, turbulence kinetic energy and heat transfer coefficient with Reynolds number were examined and discussed.

Techno-economic evaluation of a ventilation system assisted with exhaust air heat recovery, electrical heater and solar energy

OpenAIRE

Özyoğurtçu, Gamze; Mobedi, Moghtada; Özerdem, Barış

2014-01-01

The energy consumed to condition fresh air is considerable, particularly for the buildings such as cinema, theatre or gymnasium saloons. The aim of the present study is to design a ventilation system assisted with exhaust air heat recovery unit, electrical heater and stored solar energy, then to make an economical analysis based on life cycle cost (LCC) to find out its payback period. The system is able to recover thermal energy of exhaust air, store solar energy during the sunlight period an...

Quadcopter thrust optimization with ducted-propeller

Directory of Open Access Journals (Sweden)

Kuantama Endrowednes

2017-01-01

Full Text Available In relation to quadcopter body frame model, propeller can be categorized into propeller with ducted and without ducted. This study present differences between those two using CFD (Computational Fluid Dynamics method. Both categories utilize two blade-propeller with diameter of 406 (mm. Propeller rotation generates acceleration per time unit on the volume of air. Based on the behavior of generated air velocity, ducted propeller can be modeled into three versions. The generated thrust and performance on each model were calculated to determine the best model. The use of ducted propeller increases the total weight of quadcopter and also total thrust. The influence of this modeling were analyzed in detail with variation of angular velocity propeller from 1000 (rpm to 9000 (rpm. Besides the distance between propeller tip and ducted barrier, the size of ducted is also an important part in thrust optimization and total weight minimization of quadcopter.

Single and double pass solar air heaters with wire mesh as packing bed

Energy Technology Data Exchange (ETDEWEB)

Aldabbagh, L.B.Y.; Egelioglu, F. [Mechanical Engineering Department, Eastern Mediterranean University, Magosa, Mersin 10 (Turkey); Ilkan, M. [School of Computing and Tecnology, Eastern Mediterranean University, Magosa, Mersin 10 (Turkey)

2010-09-15

The thermal performances of single and double pass solar air heaters with steel wire mesh layers are used instead of a flat absorber plate are investigated experimentally. The effects of mass flow rate of air on the outlet temperature and thermal efficiency were studied. The results indicate that the efficiency increases with increasing the mass flow rate for the range of the flow rate used in this work between 0.012 and 0.038 kg/s. For the same flow rate, the efficiency of the double pass is found to be higher than the single pass by 34-45%. Moreover, the maximum efficiencies obtained for the single and the double pass air collectors are 45.93 and 83.65% respectively for the mass flow rate of 0.038 kg/s. Comparison of the results of a packed bed collector with those of a conventional collector shows a substantial enhancement in the thermal efficiency. (author)

Experimental Research of a Water-Source Heat Pump Water Heater System

OpenAIRE

Zhongchao Zhao; Yanrui Zhang; Haojun Mi; Yimeng Zhou; Yong Zhang

2018-01-01

The heat pump water heater (HPWH), as a portion of the eco-friendly technologies using renewable energy, has been applied for years in developed countries. Air-source heat pump water heaters and solar-assisted heat pump water heaters have been widely applied and have become more and more popular because of their comparatively higher energy efficiency and environmental protection. Besides use of the above resources, the heat pump water heater system can also adequately utilize an available wat...

Thermal-Hydraulic Analysis of an Experimental Reactor Cavity Cooling System with Air. Part I: Experiments; Part II: Separate Effects Tests and Modeling

International Nuclear Information System (INIS)

Corradin, Michael; Dominguez, A.; Tokuhiro, Akira; Hamman, K.

2014-01-01

This experimental study investigates the thermal hydraulic behavior and the heat removal performance for a scaled Reactor Cavity Cooling System (RCCS) with air. A quarter-scale RCCS facility was designed and built based on a full-scale General Atomics (GA) RCCS design concept for the Modular High Temperature Gas Reactor (MHTGR). The GA RCCS is a passive cooling system that draws in air to use as the cooling fluid to remove heat radiated from the reactor pressure vessel to the air-cooled riser tubes and discharged the heated air into the atmosphere. Scaling laws were used to preserve key aspects and to maintain similarity. The scaled air RCCS facility at UW-Madison is a quarter-scale reduced length experiment housing six riser ducts that represent a 9.5° sector slice of the full-scale GA air RCCS concept. Radiant heaters were used to simulate the heat radiation from the reactor pressure vessel. The maximum power that can be achieved with the radiant heaters is 40 kW with a peak heat flux of 25 kW per meter squared. The quarter-scale RCCS was run under different heat loading cases and operated successfully. Instabilities were observed in some experiments in which one of the two exhaust ducts experienced a flow reversal for a period of time. The data and analysis presented show that the RCCS has promising potential to be a decay heat removal system during an accident scenario.

Thermal-Hydraulic Analysis of an Experimental Reactor Cavity Cooling System with Air. Part I: Experiments; Part II: Separate Effects Tests and Modeling

Energy Technology Data Exchange (ETDEWEB)

Corradin, Michael [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Anderson, M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Muci, M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Hassan, Yassin [Texas A & M Univ., College Station, TX (United States); Dominguez, A. [Texas A & M Univ., College Station, TX (United States); Tokuhiro, Akira [Univ. of Idaho, Moscow, ID (United States); Hamman, K. [Univ. of Idaho, Moscow, ID (United States)

2014-10-15

This experimental study investigates the thermal hydraulic behavior and the heat removal performance for a scaled Reactor Cavity Cooling System (RCCS) with air. A quarter-scale RCCS facility was designed and built based on a full-scale General Atomics (GA) RCCS design concept for the Modular High Temperature Gas Reactor (MHTGR). The GA RCCS is a passive cooling system that draws in air to use as the cooling fluid to remove heat radiated from the reactor pressure vessel to the air-cooled riser tubes and discharged the heated air into the atmosphere. Scaling laws were used to preserve key aspects and to maintain similarity. The scaled air RCCS facility at UW-Madison is a quarter-scale reduced length experiment housing six riser ducts that represent a 9.5° sector slice of the full-scale GA air RCCS concept. Radiant heaters were used to simulate the heat radiation from the reactor pressure vessel. The maximum power that can be achieved with the radiant heaters is 40 kW with a peak heat flux of 25 kW per meter squared. The quarter-scale RCCS was run under different heat loading cases and operated successfully. Instabilities were observed in some experiments in which one of the two exhaust ducts experienced a flow reversal for a period of time. The data and analysis presented show that the RCCS has promising potential to be a decay heat removal system during an accident scenario.

HVAC; Heating, Ventilation, Air Conditioning - Aerosol Duct Sealant

Science.gov (United States)

2016-09-01

material was applied. Annual energy and cost savings were predicted based on a typical weather year for each site. The installation of the duct...Balance reports; Visible dust streaks on duct work, ceilings near supply diffusers, or electrical boxes; Comfort complaints Specific Leakage...energy consumption , depending on the HVAC system type and the location of the ducts that were sealed. The cost effectiveness of the technology is

A novel PV/T-air dual source heat pump water heater system: Dynamic simulation and performance characterization

International Nuclear Information System (INIS)

Cai, Jingyong; Ji, Jie; Wang, Yunyun; Zhou, Fan; Yu, Bendong

2017-01-01

Highlights: • The PV/T evaporator and air source evaporator connect in parallel and operate simultaneously. • A dynamic model is developed to simulate the behavior of the system. • The thermal and electrical characteristics of the PV/T evaporator are evaluated. • The contribution of the air source evaporator and PV/T evaporator has been discussed. - Abstract: To enable the heat pump water heater maintain efficient operation under diverse circumstances, a novel PV/T-air dual source heat pump water heater (PV/T-AHPWH) has been proposed in this study. In the PV/T-AHPWH system, a PV/T evaporator and an air source evaporator connect in parallel and operate simultaneously to recover energy from both solar energy and environment. A dynamic model is presented to simulate the behavior of the PV/T-AHPWH system. On this basis, the influences of solar irradiation, ambient temperature and packing factor have been discussed, and the contributions of air source evaporator and PV/T evaporator are evaluated. The results reveal that the system can obtain efficient operation with the average COP above 2.0 under the ambient temperature of 10 °C and solar irradiation of 100 W/m 2 . The PV/T evaporator can compensate for the performance degradation of the air source evaporator caused by the increasing condensing temperature. As the evaporating capacity in PV/T evaporator remains at relatively low level under low irradiation, the air source evaporator can play the main role of recovering heat. Comparing the performance of dual source heat pump system employing PV/T collector with that utilizing normal solar thermal collector, the system utilizing PV/T evaporator is more efficient in energy saving and performance improvement.

CO{sub 2} capture from oil refinery process heaters through oxyfuel combustion

Energy Technology Data Exchange (ETDEWEB)

M.B. Wilkinson; J.C. Boden; T. Gilmartin; C. Ward; D.A. Cross; R.J. Allam; N.W.Ivens [BP, Sunbury-on-Thames (United Kingdom)

2003-07-01

BP has a programme to develop technologies that could reduce greenhouse gas emissions, by the capture and storage of CO{sub 2} from existing industrial boilers and process heaters. One generic technology under development is oxyfuel combustion, with flue gas recycle. Previous studies, by three of the authors, have concluded that refinery steam boilers could be successfully converted to oxyfuel firing. Fired heaters, however, differ from boilers in several respects and so it was decided to study the feasibility of converting process heaters. Three heaters, located on BP s Grangemouth refinery, were chosen as examples, as they are typical of large numbers of heaters worldwide. In establishing the parameters of the study, it was decided that the heat fluxes to the process tubes should not be increased, compared to conventional air firing. For two of the heaters this was achieved by proposing a slightly higher recycle rate than for the boiler conversion studied earlier - the heater duty would be retained with no changes to the tubes. For the third heater, where the process duty uses only the radiant section, the CO{sub 2} capture cost and the firing rate could be reduced by lowering the recycle rate. Some air in leakage to these heaters was considered inevitable, despite measures to control it, and therefore plant to remove residual inerts from the CO{sub 2} product was designed. Cryogenic oxygen production was selected for two heaters, but for the smallest heater vacuum swing adsorption was more economic. 3 refs., 2 figs., 2 tabs.

DEVELOPMENT OF TECHNICAL DECISIONS FOR HEAT SUPPLY WITH TUBULAR GAS HEATERS

Directory of Open Access Journals (Sweden)

IRODOV V. F.

2017-05-01

Full Text Available Annotation. Problems formulation. The problem that is solved is the development of autonomous heat supply systems that reduce the capital costs of construction and increase the efficiency of the use of energy resources. One of the ways to solve this problem is the use of tubular gas heaters. For this, it is necessary to develop new technical solutions for heat supply with tubular gas heaters, as well as scientific and methodological support for the development, construction and operation of heat supply systems with tubular gas heaters. Analysis of recent research. Preliminary studies of infrared tubular gas heaters are considered, which were used to heat industrial enterprises with sufficiently high premises. The task was to extend the principles of heat supply by means of tubular heaters for heating air, water and heating medium in relatively low rooms. Goal and tasks. To lay out the development of technical solutions for heat supply with tubular gas heaters, which increase the efficiency and reliability of heat supply systems and extend the use of tubular gas heaters in heat supply. Results. Technical solutions for heat supply with tubular gas heaters have made it possible to extend their applications for heating air, water and heating medium in relatively low rooms. Scientific novelty. New technical solutions for heat supply with tubular gas heaters increase the efficiency of using fuel and energy resources at low capital costs. Practical significance. Technical solutions for heat supply using tubular heaters have the potential for wide application in the heat supply of industrial, public and residential facilities. Conclusions. For two decades, new technical solutions for heat supply with tubular gas heaters have been developed, which increase the efficiency and reliability of heat supply systems and can be widely used for autonomous heating.

Room chamber assessment of the pollutant emission properties of (nominally) low-emission unflued gas heaters

Energy Technology Data Exchange (ETDEWEB)

Brown, S.K.; Mahoney, K.J., Min Cheng [CSIRO Manufacturing and Infrastructure Technology, Victoria (Australia)

2004-07-01

Pollutant emissions from unflued gas heaters were assessed in CSIRO'a Room Dynamic Environmental Chamber. This paper describes the chamber assessment procedure and presents findings for major commercial heaters that are nominally 'low-emission'. The chamber was operated at controlled conditions of temperature, humidity, ventilation and air mixing, representative of those encountered in typical indoor environments. A fixed rate of heat removal from the chamber air ensured that the heaters operated at constant heating rates, typically {approx}6 MJ/h which simulated operation of a heater after warm-up in an insulated dwelling in south-east Australia. The pollutants assessed were nitrogen dioxide, carbon monoxide, formaldehyde, VOCs and respirable suspended particulates. One type of heater was lower emitting for nigroen dioxide, but emitted greater amounts of carbon monoxide and formaldehyde (the latter becoming significant to indoor air quality). When operated with low line pressure of slight misalignment of the gas burner, this heater became a hazardous source of these pollutants. Emissions from the heates changed little after continous operation for up to 2 months. (au)

Unregulated heat output of a storage heater

OpenAIRE

Lysak, Oleg Віталійович

2017-01-01

In the article the factors determining the heat transfer between the outer surfaces of a storage heater and the ambient air. This heat exchange is unregulated, and its definition is a precondition for assessing heat output range of this type of units. It was made the analysis of the literature on choosing insulating materials for each of the external surfaces of storage heaters: in foreign literature, there are recommendations on the use of various types of insulation depending on the type of...

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

Science.gov (United States)

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

1974-01-01

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

Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater

Directory of Open Access Journals (Sweden)

Foued Chabane

2014-03-01

Full Text Available The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s−1. Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s−1 with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater.

Science.gov (United States)

Chabane, Foued; Moummi, Noureddine; Benramache, Said

2014-03-01

The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s(-1). Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s(-1) with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

COULD A MASONRY HEATER BE THE MAIN HEAT SOURCE IN A TIGHT HOUSE?

OpenAIRE

Kasiliauskas, Jonas

2017-01-01

Masonry heaters are the oldest heating method for one family houses. Earlier houses had high leakage air-flow rates because thermal efficient insulation material was combustible by that time /20/. The masonry heater perfectly fits for air leaky houses. Nowadays, houses are more insulated and have an air tight envelope. People don’t want to spend time for supervising heating systems, that’s the reason they choose a heating system with automatism. The main aim of my thesis is to evaluate if...

Research of Dust Field Optimization Distribution Based on Parameters Change of Air Duct Outlet in Fully Mechanized Excavation Face of Coal Mine

Science.gov (United States)

Gong, Xiao-Yan; Xia, Zhi-Xin; Wu, Yue; Mo, Jin-Ming; Zhang, Xin-Yi

2017-12-01

Aiming at the problem of dust accumulation and pollution risk rising sharply in fully mechanized excavation face, which caused by the unreasonable air duct outlet airflow under the long distance driving, this paper proposes a new idea to optimize the distribution of dust by changing the angle, caliber and the front and rear distance of air duct outlet. Taking the fully mechanized excavation face of Ningtiaota coal mine which located in Shaanxi province as the research object, the numerical simulation scheme of dust field was established, the safety hazard of the distribution of original dust field was simulated and analyzed, the numerical simulation and optimization analysis of the dust distribution by changing the angle, caliber and the front and rear distance of air duct outlet was carried out, and the adjustment scheme of the optimized dust distribution was obtained, which provides a theoretical basis for reducing the probability of dust explosion and the degree of pollution.

Feed water pre-heater with two steam spaces

International Nuclear Information System (INIS)

Tratz, H.; Kelp, F.; Netsch, E.

1976-01-01

A feed water pre-heater for the two stage heating of feed water by condensing steam, having a low installed height is described, which can be installed in the steam ducts of turbines of large output, as in LWRs in nuclear power stations. The inner steam space is closed on one side by the water vessel, while the tubes of the inner steam space go straight from the water vessel, and the tubes of the outer steam space are bent into a U shape and open out into the water vessel. The two-stage preheater is thus surrounded by feedwater in two ways. (UWI) [de

Natural convection in a parallel-plate vertical channel with discrete heating by two flush-mounted heaters: effect of the clearance between the heaters

Science.gov (United States)

Sarper, Bugra; Saglam, Mehmet; Aydin, Orhan; Avci, Mete

2018-04-01

In this study, natural convection in a vertical channel is studied experimentally and numerically. One of the channel walls is heated discretely by two flush-mounted heaters while the other is insulated. The effects of the clearance between the heaters on heat transfer and hot spot temperature while total length of the heaters keeps constant are investigated. Four different settlements of two discrete heaters are comparatively examined. Air is used as the working fluid. The range of the modified Grashof number covers the values between 9.6 × 105 and 1.53 × 10.7 Surface to surface radiation is taken into account. Flow visualizations and temperature measurements are performed in the experimental study. Numerical computations are performed using the commercial CFD code ANSYS FLUENT. The results are represented as the variations of surface temperature, hot spot temperature and Nusselt number with the modified Grashof number and the clearance between the heaters as well as velocity and temperature variations of the fluid.

Collector Efficiency in Downward-Type Internal-Recycle Solar Air Heaters with Attached Fins

Directory of Open Access Journals (Sweden)

Chii-Dong Ho

2013-10-01

Full Text Available The internal-recycle operation effect on collector efficiency in downward-type rectangular solar air heaters with attached fins is theoretically investigated. It is found that considerable collector efficiency is obtainable if the collector has attached fins and the operation is carried out with internal recycling. The recycling operation increases the fluid velocity to decrease the heat transfer resistance, compensating for the undesirable effect of decreasing the heat transfer driving force (temperature difference due to remixing. The attached fins provide an enlarged heat transfer area. The order of performance in a device of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

Noise suppression in duct

International Nuclear Information System (INIS)

Ahmed, A.; Barfeh, M.A.G.

2001-01-01

In air-conditioning system the noise generated by supply fan is carried by conditioned air through the ductwork. The noise created in ductwork run may be transmission, regenerative and ductborne. Transmission noise is fan noise, regenerative noise is due to turbulence in flow and ductborne noise is the noise radiating from duct to surroundings. Some noise is attenuated in ducts also but if noise level is high then it needs to be attenuated. A simple mitre bend can attenuate-noise. This principle is extended to V and M-shape ducts with inside lining of fibreglass, which gave maximum attenuation of 77 dB and 62 dB respectively corresponding to 8 kHz frequency as compared to mitre, bend giving maximum 18 dB attenuation. Sound level meter measured sound levels with octave band filter and tests were conducted in anechoic room. A V-shape attenuator can be used at fan outlet and high frequency noise can be minimized greatly. (author)

Duct System Flammability and Air Sealing Fire Separation Assemblies in the International Residential Code

Energy Technology Data Exchange (ETDEWEB)

Rudd, A. [ABT Systems, LLC, Annville, PA (United States); Prahl, D. [IBACOS, Inc., Pittsburgh, PA (United States)

2014-12-01

IBACOS identified two barriers that limit the ability of builders to cost-effectively achieve higher energy efficiency levels in housing. These are the use of duct system materials that inherently achieve airtightness and are appropriately sized for low-load houses and the ability to air seal fire separation assemblies. The issues identified fall into a gray area of the codes.

Duct System Flammability and Air Sealing Fire Separation Assemblies in the International Residential Code

Energy Technology Data Exchange (ETDEWEB)

Rudd, A.; Prahl, D.

2014-12-01

IBACOS identified two barriers that limit the ability of builders to cost-effectively achieve higher energy efficiency levels in housing. These are (1) the use of duct system materials that inherently achieve airtightness and are appropriately sized for low-load houses and (2) the ability to air seal fire separation assemblies. The issues identified fall into a gray area of the codes.

Design and optimization of resistance wire electric heater for hypersonic wind tunnel

Science.gov (United States)

Rehman, Khurram; Malik, Afzaal M.; Khan, I. J.; Hassan, Jehangir

2012-06-01

The range of flow velocities of high speed wind tunnels varies from Mach 1.0 to hypersonic order. In order to achieve such high speed flows, a high expansion nozzle is employed in the converging-diverging section of wind tunnel nozzle. The air for flow is compressed and stored in pressure vessels at temperatures close to ambient conditions. The stored air is dried and has minimum amount of moisture level. However, when this air is expanded rapidly, its temperature drops significantly and liquefaction conditions can be encountered. Air at near room temperature will liquefy due to expansion cooling at a flow velocity of more than Mach 4.0 in a wind tunnel test section. Such liquefaction may not only be hazardous to the model under test and wind tunnel structure; it may also affect the test results. In order to avoid liquefaction of air, a pre-heater is employed in between the pressure vessel and the converging-diverging section of a wind tunnel. A number of techniques are being used for heating the flow in high speed wind tunnels. Some of these include the electric arc heating, pebble bed electric heating, pebble bed natural gas fired heater, hydrogen burner heater, and the laser heater mechanisms. The most common are the pebble bed storage type heaters, which are inefficient, contaminating and time consuming. A well designed electrically heating system can be efficient, clean and simple in operation, for accelerating the wind tunnel flow up to Mach 10. This paper presents CFD analysis of electric preheater for different configurations to optimize its design. This analysis has been done using ANSYS 12.1 FLUENT package while geometry and meshing was done in GAMBIT.

Application of computational fluid dynamics (CFD) to a gas heater used for the drying of agricultural products

Energy Technology Data Exchange (ETDEWEB)

Costa, Douglas Romeu da; Coradi, Paulo Carteri; Visser, Evan Michael; Martins, Marcio Aredes [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola

2008-07-01

The objective of this study was to evaluate a gas heater used for the drying of agricultural products. The effects of fuel, primary air and secondary air flows on the distribution on temperature and velocity in a heater were evaluated with the objective of rationalizing combustion fuel. LPG was used as the energy source to provide heated air for drying. The Navier-Stokes equations were used to resolve the problem of air and fuel flow, respecting the energy conservation, equations in the heater. From the results generated, it was confirmed that greater temperature were obtained with the convection coefficient was minimal (h = 0.01). Velocity presented a parabolic, fully developed profile. The greatest velocity was encountered in the central region of the flow, obtained when the Reynolds number was at its greatest. CFD software proved to be applicable in order to resolve heat and mass transfer problems in heaters. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

Energy Technology Data Exchange (ETDEWEB)

Beal, D.; McIlvaine , J.; Fonorow, K.; Martin, E.

2011-11-01

This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. This document illustrates guidelines for the efficient installation of interior duct systems in new housing. Interior ducts result from bringing the duct work inside a home's thermal and air barrier. Architects, designers, builders, and new home buyers should thoroughly investigate any opportunity for energy savings that is as easy to implement during construction, such as the opportunity to construct interior duct work. In addition to enhanced energy efficiency, interior ductwork results in other important advantages, such as improved indoor air quality, increased system durability and increased homeowner comfort. While the advantages of well-designed and constructed interior duct systems are recognized, the implementation of this approach has not gained a significant market acceptance. This guideline describes a variety of methods to create interior ducts including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. As communication of the intent of an interior duct system, and collaboration on its construction are paramount to success, this guideline details the critical design, planning, construction, inspection, and verification steps that must be taken. Involved in this process are individuals from the design team; sales/marketing team; and mechanical, insulation, plumbing, electrical, framing, drywall and solar contractors.

Experimental study on split air conditioner with new hybrid equipment of energy storage and water heater all year round

International Nuclear Information System (INIS)

Wang Shaowei; Liu Zhenyan; Li Yuan; Zhao Keke; Wang Zhigang

2005-01-01

This paper presents a split air conditioner with a new hybrid equipment of energy storage and water heater all year round (ACWES). The authors made a special design on the storage tank to adjust the refrigerant capacity in the storage coils under different functions, instead of adding an accumulator to the system. An ACWES prototype, rebuilt from an original split air conditioner, has been finished, and experimental study of the operation processes of the prototype was done from which some important conclusions and suggestions have been made, which were helpful in the primary design and improvement of an ACWES system for potential users

Heat Pump Water Heaters and American Homes: A Good Fit?

Energy Technology Data Exchange (ETDEWEB)

Franco, Victor; Lekov, Alex; Meyers, Steve; Letschert, Virginie

2010-05-14

Heat pump water heaters (HPWHs) are over twice as energy-efficient as conventional electric resistance water heaters, with the potential to save substantial amounts of electricity. Drawing on analysis conducted for the U.S. Department of Energy's recently-concluded rulemaking on amended standards for water heaters, this paper evaluates key issues that will determine how well, and to what extent, this technology will fit in American homes. The key issues include: 1) equipment cost of HPWHs; 2) cooling of the indoor environment by HPWHs; 3) size and air flow requirements of HPWHs; 4) performance of HPWH under different climate conditions and varying hot water use patterns; and 5) operating cost savings under different electricity prices and hot water use. The paper presents the results of a life-cycle cost analysis of the adoption of HPWHs in a representative sample of American homes, as well as national impact analysis for different market share scenarios. Assuming equipment costs that would result from high production volume, the results show that HPWHs can be cost effective in all regions for most single family homes, especially when the water heater is not installed in a conditioned space. HPWHs are not cost effective for most manufactured home and multi-family installations, due to lower average hot water use and the water heater in the majority of cases being installed in conditioned space, where cooling of the indoor environment and size and air flow requirements of HPWHs increase installation costs.

Packaged die heater

Science.gov (United States)

Spielberger, Richard; Ohme, Bruce Walker; Jensen, Ronald J.

2011-06-21

A heater for heating packaged die for burn-in and heat testing is described. The heater may be a ceramic-type heater with a metal filament. The heater may be incorporated into the integrated circuit package as an additional ceramic layer of the package, or may be an external heater placed in contact with the package to heat the die. Many different types of integrated circuit packages may be accommodated. The method provides increased energy efficiency for heating the die while reducing temperature stresses on testing equipment. The method allows the use of multiple heaters to heat die to different temperatures. Faulty die may be heated to weaken die attach material to facilitate removal of the die. The heater filament or a separate temperature thermistor located in the package may be used to accurately measure die temperature.

A simulation study on the operating performance of a solar-air source heat pump water heater

International Nuclear Information System (INIS)

Xu Guoying; Zhang Xiaosong; Deng Shiming

2006-01-01

A simulation study on the operating performance of a new type of solar-air source heat pump water heater (SAS-HPWH) has been presented. The SAS-HPWH used a specially designed flat-plate heat collector/evaporator with spiral-finned tubes to obtain energy from both solar irradiation and ambient air for hot water heating. Using the meteorological data in Nanjing, China, the simulation results based on 150 L water heating capacity showed that such a SAS-HPWH can heat water up to 55 deg. C efficiently under various weather conditions all year around. In this simulation study, the influences of solar radiation, ambient temperature and compressor capacity on the performance of the SAS-HPWH were analyzed. In order to improve the overall operating performance, the use of a variable-capacity compressor has been proposed

Compact Buried Ducts in a Hot-Humid Climate House

Energy Technology Data Exchange (ETDEWEB)

Mallay, Dave [Home Innovation Research Labs, Upper Marlboro, MD (United States)

2016-01-07

"9A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely on encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences; 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs; 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.

Integrated dry NO{sub x}/SO{sub 2} emissions control system sodium-based dry sorbent injection test report. Test period: August 4, 1993--July 29, 1995

Energy Technology Data Exchange (ETDEWEB)

Smith, R.A.; Shimoto, G.H.; Muzio, L.J. [Fossil Energy Research Corp., Laguna Hills, CA (United States); Hunt, T. [Public Service Co. of Colorado, Denver, CO (United States)

1997-04-01

The project goal is to demonstrate up to 70% reductions in NOx and SO{sub 2} emissions through the integration of: (1) down-fired low-NOx burners with overfire air; (2) Selective Non-Catalytic Reduction (SNCR) for additional NOx removal; and (3) dry sorbent injection and duct humidification for SO{sub 2} removal. This report documents the sixth phase of the test program, where the performance of dry sorbent injection with sodium compounds was evaluated as a SO{sub 2} removal technique. Dry sorbent injection was performed in-duct downstream of the air heater (ahead of the fabric filter), as well as at a higher temperature location between the economizer and air heater. Two sodium compounds were evaluated during this phase of testing: sodium sesquicarbonate and sodium bicarbonate. In-duct sodium injection with low levels of humidification was also investigated. This sixth test phase was primarily focused on a parametric investigation of sorbent type and feed rate, although boiler load and sorbent preparation parameters were also varied.

A solar assisted heat-pump dryer and water heater

International Nuclear Information System (INIS)

Hawlader, M.N.A.; Chou, S.K.; Jahangeer, K.A.; Rahman, S.M.A.

2006-01-01

Growing concern about the depletion of conventional energy resources has provided impetus for considerable research and development in the area of alternative energy sources. A solar assisted heat pump dryer and water heater found to be one of the solutions while exploring for alternative energy sources. The heat pump system is used for drying and water heating applications with the major share of the energy derived from the sun and the ambient. The solar assisted heat pump dryer and water heater has been designed, fabricated and tested. The performance of the system has been investigated under the meteorological conditions of Singapore. The system consists of a variable speed reciprocating compressor, evaporator-collector, storage tank, air cooled condenser, auxiliary heater, blower, dryer, dehumidifier, and air collector. The drying medium used is air and the drying chamber is configured to carry out batch drying of good grains. A water tank connected in series with the air cooled condenser delivers hot water for domestic applications. The water tank also ensures complete condensation of the refrigerant vapour. A simulation program is developed using Fortran language to evaluate the performance of the system and the influence of different variables. The performance indices considered to evaluate the performance of the system are: Solar Fraction (SF), Coefficient of Performance (COP) and Specific Moisture Extraction Rate (SMER). A COP value of 7.5 for a compressor speed of 1800 rpm was observed. Maximum collector efficiencies of 0.86 and 0.81 have been found for evaporator-collector and air collector, respectively. A value of the SMER of 0.79 has been obtained for a load of 20 kg and a compressor speed of 1200 rpm

Household wood heater usage and indoor leakage of BTEX in Launceston, Australia: A null result

Science.gov (United States)

Galbally, Ian E.; Gillett, Robert W.; Powell, Jennifer C.; Lawson, Sarah J.; Bentley, Simon T.; Weeks, Ian A.

A study has been conducted in Launceston, Australia, to determine within households with wood heaters the effect of leakage from the heater and flue on the indoor air concentrations of the pollutants: benzene, toluene, ethylbenzene and xylene (BTEX). The study involved three classes: 28 households without wood heaters, 19 households with wood heaters compliant with the relevant Australian Standard and 30 households with non-compliant wood heaters. Outdoor and indoor BTEX concentrations were measured in each household for 7 days during summer when there was little or no wood heater usage, and for 7 days during winter when there was widespread wood heater usage. Each participant kept a household activity diary throughout their sampling periods. For wintertime, there were no significant differences of the indoor BTEX concentrations between the three classes of households. Also there were no significant relationships between BTEX indoor concentrations within houses and several measures of the amount of wood heater use within these houses. For the households sampled in this study, the use of a wood heater within a house did not lead to BTEX release within that house and had no direct detectable influence on the concentrations of BTEX within the house. We propose that the pressure differences associated with the both the leakiness or permeability of the building envelope and the draught of the wood heater have key roles in determining whether there will be backflow of smoke from the wood heater into the house. For a leaky house with a well maintained wood heater there should be no backflow of smoke from the wood heater into the house. However backflow of smoke may occur in well sealed houses. The study also found that wood heater emissions raise the outdoor concentrations of BTEX in winter in Launceston and through the mixing of outdoor air through the building envelopes into the houses, these emissions contribute to increases in the indoor concentrations of BTEX in

Acoustic damping of air ducts. Fundamentals, hall room and real room measurements; Telefoniedaempfung von Luftdurchlaessen Grundlagen, Hallraum- und Realraum-Messungen

Energy Technology Data Exchange (ETDEWEB)

Wolters, T. [TROX GmbH, Neukirchen-Vluyn (Germany). Forschung und Entwicklung

2006-07-01

The methods and concepts of airborne noise measurement and damping are presented. Data for different types of air ducts according to DIN EN ISO7235 are presented in diagrams. Air ducts of similar geometries have similar damping characteristics. The standard measurements are compared with the producers' data, showing that there is no correlation between the measurements and the producers' data. The conclusion is drawn that measuring procedures must be standardized. Structure-borne noise transmission in pipelines is investigated in two real conference rooms. The effectiveness of sound damping measures was illustrated. In cooperation with the Fraunhofer Institute of Constructional Physics (IBPL), calculation methods using existing component characteristics were investigated. Some examples show rather good agreement between calculations and measurements. (orig.)

Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 3, Water heaters, pool heaters, direct heating equipment, and mobile home furnaces

Energy Technology Data Exchange (ETDEWEB)

1993-11-01

This is Volume 3 in a series of documents on energy efficiency of consumer products. This volume discusses energy efficiency of water heaters. Water heaters are defined by NAECA as products that utilize oil, gas, or electricity to heat potable water for use outside the heater upon demand. These are major appliances, which use a large portion (18% on average) of total energy consumed per household (1). They differ from most other appliances in that they are usually installed in obscure locations as part of the plumbing and are ignored until they fail. Residential water heaters are capable of heating water up to 180{degrees}F, although the setpoints are usually set lower.

High-Performance Ducts in Hot-Dry Climates

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, Marc [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chitwood, Rick [National Renewable Energy Laboratory (NREL), Golden, CO (United States); German, Alea [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weitzel, Elizabeth [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2015-07-30

Duct thermal losses and air leakage have long been recognized as prime culprits in the degradation of heating, ventilating, and air-conditioning (HVAC) system efficiency. Both the U.S. Department of Energy’s Zero Energy Ready Home program and California’s proposed 2016 Title 24 Residential Energy Efficiency Standards require that ducts be installed within conditioned space or that other measures be taken to provide similar improvements in delivery effectiveness (DE). Pacific Gas & Electric Company commissioned a study to evaluate ducts in conditioned space and high-performance attics (HPAs) in support of the proposed codes and standards enhancements included in California’s 2016 Title 24 Residential Energy Efficiency Standards. The goal was to work with a select group of builders to design and install high-performance duct (HPD) systems, such as ducts in conditioned space (DCS), in one or more of their homes and to obtain test data to verify the improvement in DE compared to standard practice. Davis Energy Group (DEG) helped select the builders and led a team that provided information about HPD strategies to them. DEG also observed the construction process, completed testing, and collected cost data.

Ventilation and exhaust ducts for dry storage facilities with self-heating radioactive materials

International Nuclear Information System (INIS)

Knappe, O.; Hame, W.

1986-01-01

The storage facilities are cooled by natural convection. In order to achieve this, the air inlet and outlet openings or ducts for the PWR and BWR fuel store are arranged at the level of the roof structure. There are two types of air inlet openings arranged on top and on the sides respectively but having got common inlet ducts. Air supply is improved by means of baffle noses, baffle edges, and baffle plates. The exhaust air ducts terminate near the roof structure, the openings having got dropping edges, protective sills and separating plates. (orig./PW)

Molded polymer solar water heater

Science.gov (United States)

Bourne, Richard C.; Lee, Brian E.

2004-11-09

A solar water heater has a rotationally-molded water box and a glazing subassembly disposed over the water box that enhances solar gain and provides an insulating air space between the outside environment and the water box. When used with a pressurized water system, an internal heat exchanger is integrally molded within the water box. Mounting and connection hardware is included to provide a rapid and secure method of installation.

A Comparison of Simulation Capabilities for Ducts

Energy Technology Data Exchange (ETDEWEB)

Miller, William A [ORNL; Smith, Matt K [ORNL; Gu, Lixing [Florida Solar Energy Center (FSEC); New, Joshua Ryan [ORNL

2014-11-01

Typically, the cheapest way to install a central air conditioning system in residential buildings is to place the ductwork in the attic. Energy losses due to duct-attic interactions can be great, but current whole-house models are unable to capture the dynamic multi-mode physics of the interactions. The building industry is notoriously fragmented and unable to devote adequate research resources to solve this problem. Builders are going to continue to put ducts in the attic because floor space is too expensive to closet them within living space, and there are both construction and aesthetic issues with other approaches such as dropped ceilings. Thus, there is a substantial need to publicly document duct losses and the cost of energy used by ducts in attics so that practitioners, builders, homeowners and state and federal code officials can make informed decisions leading to changes in new construction and additional retrofit actions. Thus, the goal of this study is to conduct a comparison of AtticSim and EnergyPlus simulation algorithms to identify specific features for potential inclusion in EnergyPlus that would allow higher-fidelity modeling of HVAC operation and duct transport of conditioned air. It is anticipated that the resulting analysis from these simulation tools will inform energy decisions relating to the role of ducts in future building energy codes and standards.

Utilization of air conditioner condenser as water heater in an effort to energy conservation

Science.gov (United States)

Sonawan, Hery; Saputro, Panji; Kurniawan, Iden Muhtar

2018-04-01

This paper presents an experimental study of utilization of air conditioner condenser as water heater. Modification of existing air conditioner system is an effort to harvest waste heat energy from condenser. Modification is conducted in order to test the system into two mode tests, first mode with one condenser and second mode with two condensers. Harvesting the waste heat from condenser needs a theoretical and practice study to see how much the AC performance changes if modifications are made. It should also be considered how the technique of harvesting waste heat for water heating purposes. From the problem, this paper presents a comparison between AC performance before and after modification. From the experiment, an increase in compressor power consumption is 4.3% after adding a new condenser. The hot water temperature is attained to 69 °C and ready for warm bath. The increase in power consumption is not too significant compared to the attainable hot water temperature. Also seen that the value of condenser Performance Factor increase from 5.8 to 6.25 or by 7.8%.

Experimental Study of a Novel Direct-Expansion Variable Frequency Finned Solar/Air-Assisted Heat Pump Water Heater

Directory of Open Access Journals (Sweden)

Jing Qin

2018-01-01

Full Text Available A novel direct expansion variable frequency finned solar/air-assisted heat pump water heater was fabricated and tested in the enthalpy difference lab with a solar simulator. A solar/air source evaporator-collector with an automatic lifting glass cover plate was installed on the system. The system could be operated in three modes, namely, air, solar, and dual modes. The effects of the ambient temperature, solar irradiation, compressor frequency, and operating mode on the performance of this system were studied in this paper. The experimental results show that the ambient temperature, solar irradiation, and operating mode almost have no effect on the energy consumption of the compressor. When the ambient temperature and the solar irradiation were increased, the COP was found to increase with decreasing heating time. Also, when the compressor frequency was increased, an increase in the energy consumption of the compressor and the heat gain of the evaporator were noted with a decrease in the heating time.

Measured Performance of a Varied Airflow Small-Diameter Duct System

Energy Technology Data Exchange (ETDEWEB)

Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

2017-03-01

This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

Measured Performance of a Varied Airflow Small-Diameter Duct System

Energy Technology Data Exchange (ETDEWEB)

Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

2017-03-16

This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

The thermal performance of the two-pass, two-glass-cover solar air heater

Energy Technology Data Exchange (ETDEWEB)

Persad, P.; Sateunanathan, S.

1983-08-01

Analytic models are developed for the performance prediction of a two-glass-cover solar air heater operated in both the single-pass and two-pass modes. It is shown that the two-pass mode of operation is superior to the single-pass mode of operation over the range of collector inlet temperatures considered. This is seen to be mainly due to the fact that, in the two-pass mode of operation, the outer glass cover is cooled by the working fluid, thereby reducing the top losses. It is also shown that the performance in the two-pass mode of operation is independent of length, over the range of collector lengths considered, and that a critical plate spacing, dependent on the temperature level of operation of the collector, is indicated. Predicted values of performance are in good agreement with experimental results.

Experimental Research of a Water-Source Heat Pump Water Heater System

Directory of Open Access Journals (Sweden)

Zhongchao Zhao

2018-05-01

Full Text Available The heat pump water heater (HPWH, as a portion of the eco-friendly technologies using renewable energy, has been applied for years in developed countries. Air-source heat pump water heaters and solar-assisted heat pump water heaters have been widely applied and have become more and more popular because of their comparatively higher energy efficiency and environmental protection. Besides use of the above resources, the heat pump water heater system can also adequately utilize an available water source. In order to study the thermal performance of the water-source heat pump water heater (WSHPWH system, an experimental prototype using the cyclic heating mode was established. The heating performance of the water-source heat pump water heater system, which was affected by the difference between evaporator water fluxes, was investigated. The water temperature unfavorably exceeded 55 °C when the experimental prototype was used for heating; otherwise, the compressor discharge pressure was close to the maximum discharge temperature, which resulted in system instability. The evaporator water flux allowed this system to function satisfactorily. It is necessary to reduce the exergy loss of the condenser to improve the energy utilization of the system.

Evaluation of PEGIT duct connection system

Energy Technology Data Exchange (ETDEWEB)

Walker, Iain S.; Brenner, Douglas E.; Sherman, Max H.; Dickerhoff, Darryl J.

2003-08-01

Most air duct system components are assembled in the field and are mechanically fastened by sheet metal screws (for sheet metal-to-sheet metal) or by drawbands (for flex duct-to-sheet metal). Air sealing is separate from this mechanical fastening and is usually achieved using tape or mastic products after mechanical fastening. Field observations have shown that mechanical fastening rarely meets code or manufacturers requirements and that sealing procedures are similarly inconsistent. To address these problems, Proctor Engineering Group (PEG) is developing a system of joining ducts (called PEGIT) that combines the mechanical fastening and sealing into a single self-contained procedure. The PEGIT system uses a shaped flexible seal between specially designed sheet metal duct fittings to both seal and fasten duct sections together. Figure 1 shows the inner duct fitting complete with rubber seal. This seal provides the air seal for the completed fitting and is shaped to allow the inner and outer fittings to slide together, and then to lock the fittings in place. The illustration in Figure 2 shows the approximate cross section of the rubber seal that shows how the seal has a lip that is angled backwards. This angled lip allows the joint to be pushed together by folding flat but then its long axis makes it stiff in the pulling apart direction. This study was undertaken to assist PEG in some of the design aspects of this system and to test the performance of the PEGIT system. This study was carried out in three phases. The initial phase evaluated the performance of a preliminary seal design for the PEGIT system. After the first phase, the seal was redesigned and this new seal was evaluated in the second phase of testing. The third phase performed more detailed testing of the second seal design to optimize the production tolerances of the sheet metal fittings. This report summarizes our findings from the first two phases and provides details about the third phase of testing.

Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 1, Methodology

Energy Technology Data Exchange (ETDEWEB)

1993-11-01

The Energy Policy and Conservation Act (P.L. 94-163), as amended, establishes energy conservation standards for 12 of the 13 types of consumer products specifically covered by the Act. The legislation requires the Department of Energy (DOE) to consider new or amended standards for these and other types of products at specified times. DOE is currently considering amending standards for seven types of products: water heaters, direct heating equipment, mobile home furnaces, pool heaters, room air conditioners, kitchen ranges and ovens (including microwave ovens), and fluorescent light ballasts and is considering establishing standards for television sets. This Technical Support Document presents the methodology, data, and results from the analysis of the energy and economic impacts of the proposed standards. This volume presents a general description of the analytic approach, including the structure of the major models.

Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

Energy Technology Data Exchange (ETDEWEB)

Sparn, B.; Hudon, K.; Christensen, D.

2014-06-01

This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of U.S. climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt™ whole-house building simulations.

Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

Energy Technology Data Exchange (ETDEWEB)

Sparn, B.; Hudon, K.; Christensen, D.

2014-06-01

This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt(tm) whole-house building simulations.

Effect of heat recovery water heater system on the performance of residential split air conditioner using hydrocarbon refrigerant (HCR22)

Science.gov (United States)

Aziz, A.; Thalal; Amri, I.; Herisiswanto; Mainil, A. K.

2017-09-01

This This paper presents the performance of residential split air conditioner (RSAC) using hydrocarbon refrigerant (HCR22) as the effect on the use of heat recovery water heater system (HRWHS). In this study, RSAC was modified with addition of dummy condenser (trombone coil type) as heat recovery water heater system (HRWHS). This HRWHS is installed between a compressor and a condenser by absorbing a part of condenser waste heat. The results show that RSAC with HRWHS is adequate to generate hot water with the temperature range about 46.58˚C - 48.81˚C when compared to without HRWHS and the use of dummy condenser does not give significant effect to the split air conditioner performance. When the use of HRWHS, the refrigerant charge has increase about 19.05%, the compressor power consumption has slightly increase about 1.42% where cooling capacity almost the same with slightly different about 0.39%. The condenser heat rejection is lower about 2.68% and the COP has slightly increased about 1.05% when compared to without HRWHS. The use of HRWHS provide free hot water, it means there is energy saving for heating water without negative impact to the system performance of RSAC.

Characterization of Emissions from Heaters Burning Leaded Diesel Fuel in Unvented Tents

National Research Council Canada - National Science Library

Cheng, Yung-Sung

1999-01-01

.... The air exchange rate ranged from 1 to 3.4/hr when the tent doors were open and closed. The air exchange rate-and the type-of fuel and heater were very important factors in determining the pollutant concentrations inside the tent...

Critical analysis of the condensation of water vapor at external surface of the duct

Science.gov (United States)

Kumar, Dileep; Memon, Rizwan Ahmed; Memon, Abdul Ghafoor; Ali, Intizar; Junejo, Awais

2018-01-01

In this paper, the effects of contraction of the insulation of the air duct of heating, ventilation, and air conditioning (HVAC) system is investigated. The compression of the insulation contracts it at joint, turn and other points of the duct. The energy loss and the condensation resulted from this contraction are also estimated. A mathematical model is developed to simulate the effects of this contraction on the heat gain, supply air temperature and external surface temperature of the duct. The simulation uses preliminary data obtained from an HVAC system installed in a pharmaceutical company while varying the operating conditions. The results reveal that insulation thickness should be kept greater than 30 mm and the volume flow rate of the selected air distribution system should be lower than 1.4m3/s to subside condensation on the external surface of the duct. Additionally, the optimum insulation thickness was determined by considering natural gas as an energy source and fiberglass as an insulation material. The optimum insulation thickness determined for different duct sizes varies from 28 to 45 mm, which is greater than the critical insulation thickness. Therefore, the chances of condensation on the external surface of the duct could be avoided at an optimum insulation thickness. Moreover, the effect of pressure loss coefficient of the duct fitting of air distribution system is estimated. The electricity consumption in air handling unit (AHU) decreases from 2.1 to 1.5 kW by decreasing the pressure loss coefficient from 1.5 to 0.5.

Comparison between predicted duct effectiveness from proposed ASHRAE Standard 152P and measured field data for residential forced air cooling systems; TOPICAL

International Nuclear Information System (INIS)

Siegel, Jeffrey A.; McWilliams, Jennifer A.; Walker, Iain S.

2002-01-01

The proposed ASHRAE Standard 152P ''Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems'' (ASHRAE 2002) has recently completed its second public review. As part of the standard development process, this study compares the forced air distribution system ratings provided by the public review draft of Standard 152P to measured field results. 58 field tests were performed on cooling systems in 11 homes in the summers of 1998 and 1999. Seven of these houses had standard attics with insulation on the attic floor and a well-vented attic space. The other four houses had unvented attics where the insulation is placed directly under the roof deck and the attic space is not deliberately vented. Each house was tested under a range of summer weather conditions at each particular site, and in some cases the amount of duct leakage was intentionally varied. The comparison between 152P predicted efficiencies and the measured results includes evaluation of the effects of weather, duct location, thermal conditions, duct leakage, and system capacity. The results showed that the difference between measured delivery effectiveness and that calculated using proposed Standard 152P is about 5 percentage points if weather data, duct leakage and air handler flow are well known. However, the accuracy of the standard is strongly dependent on having good measurements of duct leakage and system airflow. Given that the uncertainty in the measured delivery effectiveness is typically also about 5 percentage points, the Standard 152P results are acceptably close to the measured data

Experimental investigation of thermal performance of a double-flow solar air heater having aluminium cans

Energy Technology Data Exchange (ETDEWEB)

Ozgen, Filiz; Esen, Mehmet; Esen, Hikmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey)

2009-11-15

This study experimentally investigates a device for inserting an absorbing plate made of aluminium cans into the double-pass channel in a flat-plate solar air heater (SAH). This method substantially improves the collector efficiency by increasing the fluid velocity and enhancing the heat-transfer coefficient between the absorber plate and air. These types of collectors had been designed as a proposal to use aluminium materials to build absorber plates of SAHs at a suitable cost. The collector had been covered with a 4-mm single glass plate, in order to reduce convective loses to the atmosphere. Three different absorber plates had been designed and tested for experimental study. In the first type (Type I), cans had been staggered as zigzag on absorber plate, while in Type II they were arranged in order. Type III is a flat plate (without cans). Experiments had been performed for air mass flow rates of 0.03 kg/s and 0.05 kg/s. The highest efficiency had been obtained for Type I at 0.05 kg/s. Also, comparison between the thermal efficiency of the SAH tested in this study with the ones reported in the literature had been presented, and a good agreement had been found. (author)

Algorithm of dynamic regulation of a system of duct, for a high accuracy climatic system

Science.gov (United States)

Arbatskiy, A. A.; Afonina, G. N.; Glazov, V. S.

2017-11-01

Currently, major part of climatic system, are stationary in projected mode only. At the same time, many modern industrial sites, require constant or periodical changes in technological process. That is 80% of the time, the industrial site is not require ventilation system in projected mode and high precision of climatic parameters must maintain. While that not constantly is in use for climatic systems, which use in parallel for different rooms, we will be have a problem for balance of duct system. For this problem, was created the algorithm for quantity regulation, with minimal changes. Dynamic duct system: Developed of parallel control system of air balance, with high precision of climatic parameters. The Algorithm provide a permanent pressure in main duct, in different a flow of air. Therefore, the ending devises air flow have only one parameter for regulation - flaps open area. Precision of regulation increase and the climatic system provide high precision for temperature and humidity (0,5C for temperature, 5% for relative humidity). Result: The research has been made in CFD-system - PHOENICS. Results for velocity of air in duct, for pressure of air in duct for different operation mode, has been obtained. Equation for air valves positions, with different parameters for climate in room’s, has been obtained. Energy saving potential for dynamic duct system, for different types of a rooms, has been calculated.

Nonequilibrium Supersonic Freestream Studied Using Coherent Anti-Stokes Raman Spectroscopy

Science.gov (United States)

Cutler, Andrew D.; Cantu, Luca M.; Gallo, Emanuela C. A.; Baurle, Rob; Danehy, Paul M.; Rockwell, Robert; Goyne, Christopher; McDaniel, Jim

2015-01-01

Measurements were conducted at the University of Virginia Supersonic Combustion Facility of the flow in a constant-area duct downstream of a Mach 2 nozzle. The airflow was heated to approximately 1200 K in the facility heater upstream of the nozzle. Dual-pump coherent anti-Stokes Raman spectroscopy was used to measure the rotational and vibrational temperatures of N2 and O2 at two planes in the duct. The expectation was that the vibrational temperature would be in equilibrium, because most scramjet facilities are vitiated air facilities and are in vibrational equilibrium. However, with a flow of clean air, the vibrational temperature of N2 along a streamline remains approximately constant between the measurement plane and the facility heater, the vibrational temperature of O2 in the duct is about 1000 K, and the rotational temperature is consistent with the isentropic flow. The measurements of N2 vibrational temperature enabled cross-stream nonuniformities in the temperature exiting the facility heater to be documented. The measurements are in agreement with computational fluid dynamics models employing separate lumped vibrational and translational/rotational temperatures. Measurements and computations are also reported for a few percent steam addition to the air. The effect of the steam is to bring the flow to thermal equilibrium, also in agreement with the computational fluid dynamics.

Building America Case Study: High-Velocity Small-Diameter Duct System, Pittsburgh, Pennsylvania

Energy Technology Data Exchange (ETDEWEB)

2017-04-01

This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

24 CFR 3280.715 - Circulating air systems.

Science.gov (United States)

2010-04-01

... factory-made flexible ducts, including trunks, branches, risers, crossover ducts, and crossover duct... factory-made flexible air ducts and air connectors shall be listed in accordance with UL Standard 181B...

Experimental study on the performance of a multi-functional domestic air conditioner with integrated water heater

International Nuclear Information System (INIS)

Dong, Jiankai; Li, Hui; Yao, Yang; Jiang, Yiqiang; Zhang, Xinran

2017-01-01

Highlights: • A novel MDACWH was presented and experimentally studied. • MDACWH has high performance on making domestic hot water and air conditioning. • The time for heating water reduced to 22.0 min after modification. • Average COP reached 4.32, which was 1.58 times higher than the unmodified unit. - Abstract: The recovery of condenser heat is concerned one of the most effective methods to curb energy consumption in residential dwellings. Aiming at recovering the condenser heat of domestic air conditioner, this paper experimentally studied a multi-functional domestic air conditioner with integrated water heater (MDACWH) which can effectively provide space – cooling and domestic hot water simultaneously. The dynamic operation characteristics, such as hot water supply and energy efficiency were tested to verify the availability of the MDACWH. The results showed that the MDACWH can effectively heat the domestic hot water without losing its cooling capacity. It was also found that with the use of MDACWH, the coefficient of comprehensive energy performance of the MDACWH was about 1.58 times higher than that of the unmodified experimental unit. Furthermore, the water-heating time was shorten remarkably from 128.5 min to 22.0 min. The novel domestic air conditioner, compared with the unmodified initial prototype, can be more practical and provide significant energy savings in space-cooling and hot water supply.

Energy, exergy, environmental and economic analysis of industrial fired heaters based on heat recovery and preheating techniques

International Nuclear Information System (INIS)

Shekarchian, M.; Zarifi, F.; Moghavvemi, M.; Motasemi, F.; Mahlia, T.M.I.

2013-01-01

Highlights: • 4-E analysis of a typical industrial grade fired heater unit is studied. • This analysis is accomplished for the first time in this study. • Heat recovery and air preheating lead to substantial reduction in the fuel consumption. • The company’s current costs are tremendously reduced by these methods. • The methods lead to mitigation in GHG emission and to reduction in the associated taxes. - Abstract: Fired heaters are ubiquitous in both the petroleum and petrochemical industries, due to it being vital in their day to day operations. They form major components in petroleum refineries, petrochemical facilities, and processing units. This study was commissioned in order to analyze the economic benefits of incorporating both heat recovery and air preheating methods into the existing fired heater units. Four fired heater units were analyzed from the energy and environmental point of views. Moreover, the second law efficiency and the rate of irreversibility were also analyzed via the exergy analysis. Both analyses was indicative of the fact that the heat recovery process enhances both the first and second law efficiencies while simultaneously assisting in the production of high and low pressure water steam. The implementation and usage of the process improves the thermal and exergy efficiencies from 63.4% to 71.7% and 49.4%, to 54.8%, respectively. Additionally, the heat recovery and air preheating methods leads to a substantial reduction in fuel consumption, in the realm of up to 7.4%, while also simultaneously decreasing heat loss and the irreversibility of the unit. Nevertheless, the results of the economic analysis posits that although utilizing an air preheater unit enhances the thermal performance of the system, due to the air preheater’s capital and maintenance costs, incorporating an air preheater unit to an existing fired heater is not economically justifiable. Furthermore, the results of the sensitivity analysis and payback period

Energy Efficiency Modelling of Residential Air Source Heat Pump Water Heater

Directory of Open Access Journals (Sweden)

Cong Toan Tran

2016-03-01

Full Text Available The heat pump water heater is one of the most energy efficient technologies for heating water for household use. The present work proposes a simplified model of coefficient of performance and examines its predictive capability. The model is based on polynomial functions where the variables are temperatures and the coefficients are derived from the Australian standard test data, using regression technics. The model enables to estimate the coefficient of performance of the same heat pump water heater under other test standards (i.e. US, Japanese, European and Korean standards. The resulting estimations over a heat-up phase and a full test cycle including a draw off pattern are in close agreement with the measured data. Thus the model allows manufacturers to avoid the need to carry out physical tests for some standards and to reduce product cost. The limitations of the methodology proposed are also discussed.

An experimental investigation of performance of a double pass solar air heater with thermal storage medium

Directory of Open Access Journals (Sweden)

Ali Hafiz Muhammad

2015-01-01

Full Text Available The performance of a double pass solar air heater was experimentally investigated using four different configurations. First configuration contained only absorber plate whereas copper tubes filled with thermal storage medium (paraffin wax were added on the absorber plate in the second configuration. Aluminum and steel rods as thermal enhancer were inserted in the middle of paraffin wax of each tube for configurations three and four respectively. Second configuration provided useful heat for about 1.5 hours after the sunset compared to first configuration. Configurations three and four provided useful heat for about 2 hours after the sunset. The maximum efficiency of about 96% was achieved using configuration three (i.e. using Aluminum rods in the middle of copper tubes filled with paraffin wax.

High accuracy acoustic relative humidity measurement in duct flow with air.

Science.gov (United States)

van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

2010-01-01

An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0-12 m/s with an error of ± 0.13 m/s, temperature 0-100 °C with an error of ± 0.07 °C and relative humidity 0-100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

Modelling the dynamics of the cogeneration power plant gas-air duct

Directory of Open Access Journals (Sweden)

Аnatoliy N. Bundyuk

2014-12-01

Full Text Available Introducing into wide practice the cogeneration power plants (or CHP is one of promising directions of the Ukrainian small-scale power engineering development. Thermal and electric energy generation using the same fuel kind can increase the overall plant efficiency. That makes it appropriate to use CHPs at compact residential areas, isolated industrial enterprises constituting one complex with staff housing area, at sports complexes, etc. The gas-air duct of the cogeneration power plant has been considered as an object of the diesel-generator shaft velocity control. The developed GAD mathematical model, served to analyze the CHP dynamic characteristics as acceleration curves obtained under different external disturbances in the MathWorks MATLAB environment. According to the electric power generation technology requirements a convenient transition process type has been selected, with subsequent identification of the diesel-generator shaft rotation speed control law.

Helium heater design for the helium direct cycle component test facility. [for gas-cooled nuclear reactor power plant

Science.gov (United States)

Larson, V. R.; Gunn, S. V.; Lee, J. C.

1975-01-01

The paper describes a helium heater to be used to conduct non-nuclear demonstration tests of the complete power conversion loop for a direct-cycle gas-cooled nuclear reactor power plant. Requirements for the heater include: heating the helium to a 1500 F temperature, operating at a 1000 psia helium pressure, providing a thermal response capability and helium volume similar to that of the nuclear reactor, and a total heater system helium pressure drop of not more than 15 psi. The unique compact heater system design proposed consists of 18 heater modules; air preheaters, compressors, and compressor drive systems; an integral control system; piping; and auxiliary equipment. The heater modules incorporate the dual-concentric-tube 'Variflux' heat exchanger design which provides a controlled heat flux along the entire length of the tube element. The heater design as proposed will meet all system requirements. The heater uses pressurized combustion (50 psia) to provide intensive heat transfer, and to minimize furnace volume and heat storage mass.

Temperature measurements from a horizontal heater test in G-Tunnel

International Nuclear Information System (INIS)

Lin, Wunan; Ramirez, A.L.; Watwood, D.

1991-10-01

A horizontal heater test was conducted in G-Tunnel, Nevada Test Site, to study the hydrothermal response of the rock mass due to a thermal loading. The results of the temperature measurements are reported here. The measured temperatures agree well with a scoping calculation that was performed using a model which investigates the transport of water, vapor, air, and heat in fractured porous media. Our results indicate that the temperature field might be affected by the initial moisture content of the rock, the fractures in the rock, the distance from the free surface of the alcove wall, and the temperature distribution on the heater surface. Higher initial moisture content, higher fracture density, and cooling from the alcove wall tend to decrease the measured temperature. The temperature on top of the horizontal heater can was about 30 degrees C greater than at the bottom throughout most of the heating phase, causing the rock temperatures above the heater to be greater than those below. Along a radius from the center of the heater, the heating created a dry zone, followed by a boiling zone and condensation zone. Gravity drainage of the condensed water in the condensation zone had a strong effect on the boiling process in the test region. The temperatures below and to the side of the heater indicated a region receiving liquid drainage from an overlying region of condensation. We verified that a thermocouple in a thin-wall tubing measures the same temperature as one grouted in a borehole

Investigations on the performance of a double pass, hybrid - type (PV/T) solar air heater

Energy Technology Data Exchange (ETDEWEB)

Srinivas, M.; Jayaraj, S. [Department of Mechanical Engineering, National Institute of Technology, Calicut-673601 (India)

2013-07-01

A solar hybrid energy system having photovoltaic and thermal (PV/T) devices, which produces both thermal and electrical energies simultaneously is considered for analysis. A double pass hybrid solar air (PV/T) heater with slats is designed and fabricated to study its thermal and electrical performance. Air as a heat removing fluid is made to flow through upper and lower channels of the collector. The collector is designed in such a way that the absorber plate is partially covered by solar cells. The raise in temperature of the solar cell is expected to decrease its electrical performance. Thin metallic strips called slats are attached longitudinally at the bottom side of the absorber plate to improve the system performance by increasing the cooling rate of the absorber plate. Thermal and electrical performances of the whole system at varying cooling conditions are presented. An artificial neural network model is used for forecasting the system performance at any desired conditions. The proposed model can be successfully used for evaluating the effect of different operating parameters under different ambient conditions for predicting the overall performance of the system.

Reverse Flow Engine Core Having a Ducted Fan with Integrated Secondary Flow Blades

Science.gov (United States)

Kisska, Michael K. (Inventor); Princen, Norman H. (Inventor); Kuehn, Mark S. (Inventor); Cosentino, Gary B. (Inventor)

2014-01-01

Secondary air flow is provided for a ducted fan having a reverse flow turbine engine core driving a fan blisk. The fan blisk incorporates a set of thrust fan blades extending from an outer hub and a set of integral secondary flow blades extending intermediate an inner hub and the outer hub. A nacelle provides an outer flow duct for the thrust fan blades and a secondary flow duct carries flow from the integral secondary flow blades as cooling air for components of the reverse flow turbine engine.

SNM holdup assessment of Los Alamos exhaust ducts

International Nuclear Information System (INIS)

Marshall, R.S.

1994-02-01

Fissile material holdup in glovebox and fume hood exhaust ducting has been quantified for all Los Alamos duct systems. Gamma-based, nondestructive measurements were used to quantify holdup. The measurements were performed during three measurement campaigns. The first campaign, Phase I, provided foot-by-foot, semiquantitative measurement data on all ducting. These data were used to identify ducting that required more accurate (quantitative) measurement. Of the 280 duct systems receiving Phase I measurements, 262 indicated less than 50 g of fissile holdup and 19 indicated fissile holdup of 50 or more grams. Seven duct systems were measured in a second campaign, called Series 1, Phase II. Holdup estimates on these ducts ranged from 421 g of 235 U in a duct servicing a shut-down uranium-machining facility to 39 g of 239 Pu in a duct servicing an active plutonium-processing facility. Measurements performed in the second campaign proved excessively laborious, so a third campaign was initiated that used more efficient instrumentation at some sacrifice in measurement quality. Holdup estimates for the 12 duct systems measured during this third campaign ranged from 70 g of 235 U in a duct servicing analytical laboratories to 1 g of 235 U and 1 g of 239 Pu in a duct carrying exhaust air to a remote filter building. These quantitative holdup estimates support the conclusion made at the completion of the Phase I measurements that only ducts servicing shut-down uranium operations contain about 400 g of fissile holdup. No ventilation ducts at Los Alamos contain sufficient fissile material holdup to present a criticality safety concern

Immersible solar heater for fluids

Science.gov (United States)

Kronberg, James W.

1995-01-01

An immersible solar heater comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

High Accuracy Acoustic Relative Humidity Measurement inDuct Flow with Air

Directory of Open Access Journals (Sweden)

Cees van der Geld

2010-08-01

Full Text Available An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0–12 m/s with an error of ±0.13 m/s, temperature 0–100 °C with an error of ±0.07 °C and relative humidity 0–100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

The impact of duct-to-duct interaction on the hex duct dilation

International Nuclear Information System (INIS)

Lee, M.J.; Chang, L.K.; Lahm, C.E.; Porter, D.L.

1992-01-01

Dilation of the hex duct is an important factor in the operational lifetime of fuel subassemblies in liquid metal fast reactors. It is caused primarily by the irradiation-enhanced creep and void swelling of the hex duct material. Excessive dilation may jeopardize subassembly removal from the core or cause a subassembly storage problem where the grid size of the storage basket is limited. Dilation of the hex duct in Experimental Breeder Reactor II (EBR-II) limits useful lifetime because of these storage basket limitations. It is, therefore, important to understand the hex duct dilation behavior to guide the design and in-core management of fuel subassemblies in a way that excessive duct deformation can be avoided. To investigate the dilation phenomena, finite-element models of the hex duct have been developed. The inelastic analyses were performed using the structural analysis code, ANSYS. Both Type 316 and D9 austenitic stainless steel ducts are considered. The calculated dilations are in good agreement with profilometry measurements made after irradiation. The analysis indicates that subassembly interaction is an important parameter in addition to neutron fluence and temperature in determining hex duct dilation. 5 refs

Effect of Ducted HPWH on Space-Conditioning and Water Heating Energy Use -- Central Florida Lab Home

Energy Technology Data Exchange (ETDEWEB)

Colon, Carlos [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Martin, Eric [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Parker, Danny [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States)

2016-11-01

The purpose of this research is to investigate the impact of ducted heat pump water heaters (HPWHs) on space conditioning and water heating energy use in residential applications. Two identical HPWHs, each of 60 gallon capacity were tested side by side at the Flexible Residential Test facility (FRTF) laboratories of the Florida Solar Energy Center (FSEC) campus in Cocoa, Florida. The water heating experiments were run in each test house from July 2014 until February 2015.

Coupled solar still, solar heater

Energy Technology Data Exchange (ETDEWEB)

Davison, R R; Harris, W B; Moor, D H; Delyannis, A; Delyannis, E [eds.

1976-01-01

Computer simulation of combinations of solar stills and solar heaters indicates the probable economic advantage of such an arrangement in many locations if the size of the heater is optimized relative to that of the still. Experience with various low cost solar heaters is discussed.

Effects of explosion-generated shock waves in ducts

International Nuclear Information System (INIS)

Busby, M.R.; Kahn, J.E.; Belk, J.P.

1976-01-01

An explosion in a space causes an increase in temperature and pressure. To quantify the challenge that will be presented to essential components in a ventilation system, it is necessary to analyze the dynamics of a shock wave generated by an explosion, with attention directed to the propagation of such a wave in a duct. Using the equations of unsteady flow and shock tube theory, a theoretical model has been formulated to provide flow properties behind moving shock waves that have interacted with various changes in duct geometry. Empirical equations have been derived to calculate air pressure, temperature, Mach number, and velocity in a duct following an explosion

Rancang Bangun dan Studi Eksperimen Alat Penukar Panas untuk Memanfaatkan Energi Refrigerant Keluar Kompresor AC sebagai Pemanas Air pada ST/D=8 dengan Variasi Volume Air

Directory of Open Access Journals (Sweden)

Fajri Chairbowo

2017-01-01

Full Text Available Abstrak­- Kebutuhan masyarakat terhadap air hangat semakin meningkat. Hal itu disebabkan air hangat mempunyai berbagai manfaat. Air hangat efektif dalam melarutkan lemak ataupun sabun, serta air hangat dapat melancarkan peredaran darah manusia ketika digunakan. Demi efisiensi dalam penggunaan energi, penelitian yang dilakukan tentang pemanfaatan panas buang dari sistem refrigerasi.. Sebelum panas dibuang ke lingkungan, water heater ditambahkan oleh penulis ke sistem refrigerasi yang peletakkannya sesudah proses kompresi. Dimana water heater akan mengambil kalor dari refrigeran pemanas yang melintas sesudah dari kompresor. Sistem refrigerasi yang digunakan mempunyai daya  1 HP (746 Watt. Dalam penelitian ini sudah ditetapkan diameter tube dari water heater adalah 1 cm dengan jarak transversal setiap tube 8 cm, fluida yang mengalir di dalam tube adalah R-22 dan fluida diam yang berada di dalam tangki adalah air. Langkah awal dari penelitian ini  adalah melakukan pengujian  sistem AC split untuk mendapatkan data-data yang dibutuhkan dalam perancangan water heater. Tahap selanjutnya adalah studi numerik dimana studi numerik dilakukan secara dua dimensi dengan kondisi steady, incompressible, dan laminar dengan prinsip Computational Fluid Dynamics (CFD, menggunakan perangkat lunak GAMBIT 2.4.6 untuk tahap pembuatan domain dan disimulasikan dengan perangkat lunak FLUENT 6.3.26. Tahap terakhir adalah eksperimen yang bertujuan untuk mengetahui water heater yang dibuat sesuai dengan rancangan penulis. Kemudian water heater yang sudah dibuat, dipasang ke sistem AC split. Pada tahap eksperimen, penulis melakukan variasi terhadap volume air di tangki, yaitu 75 liter, 85 liter dan 100 liter. Hasil dari simulasi numerik menunjukkan fenomena perpindahan panas pada water heater, yang berupa kontur temperatur, kontur kecepatan dan velocity vector dalam bentuk dua dimensi tampak samping water heater. Hasil dari studi eksperimen ini menunjukkan nilai

46 CFR 182.320 - Water heaters.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Water heaters. 182.320 Section 182.320 Shipping COAST...) MACHINERY INSTALLATION Auxiliary Machinery § 182.320 Water heaters. (a) A water heater must meet the...), except that an electric water heater is also acceptable if it: (1) Has a capacity of not more than 454...

Effectiveness of duct sealing and duct insulation in multi-family buildings. Final report

Energy Technology Data Exchange (ETDEWEB)

Karins, N.H.; Tuluca, A.; Modera, M.

1997-07-01

This research investigated the cost-effectiveness of sealing and insulating the accessible portions of duct systems exposed to unconditioned areas in multifamily housing. Airflow and temperature measurements were performed in 25 apartments served by 10 systems a 9 multi-family properties. The measurements were performed before and after each retrofit, and included apartment airflow (supply and return), duct system temperatures, system fan flow and duct leakage area. The costs for each retrofit were recorded. The data were analyzed and used to develop a prototypical multifamily house. This prototype was used in energy simulations (DOE-2.1E) and air infiltration simulations (COMIS 2.1). The simulations were performed for two climates: New York City and Albany. In each climate, one simulation was performed assuming the basement was tight, and another assuming the basement was leaky. Simulation results and average retrofit costs were used to calculate cost-effectiveness. The results of the analysis indicate that sealing leaks of the accessible ductwork is cost-effective under all conditions simulated (simple payback was between 3 and 4 years). Insulating the accessible ductwork, however, is only cost-effective for buildings with leaky basement, in both climates (simple paybacks were less than 5 years). The simple payback period for insulating the ducts in buildings with tight basements was greater than 10 years, the threshold of cost-effectiveness for this research. 13 refs., 5 figs., 27 tabs.

46 CFR 119.320 - Water heaters.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Water heaters. 119.320 Section 119.320 Shipping COAST... Machinery § 119.320 Water heaters. (a) A water heater must meet the requirements of Parts 53 and 63 in... electric water heater is also acceptable if it: (1) Has a capacity of not more than 454 liters (120 gallons...

Development of design program for small-sized gas absorption chiller/heaters

Energy Technology Data Exchange (ETDEWEB)

Yoon, J.I.; Kwon, O.K.; Moon, C.K. [Pukyong National University, Pusan (Korea); Yang, Y.M.; Kim, H.Y. [R and D Center, Korea Gas Corporation, Ansan (Korea)

1999-10-01

Analysis of basic data is performed for development of small size water-cooled household absorption chiller/heater using non CFC refrigerant, analytic simulation program of air cooling performance is developed that system has 1.5-10RT of air cooling performance, we perform cycle analysis and numerical simulation. We develope a performance analysis of simulation program to perform a basic design for 1.5-10RT apparatus of small size system of development model in gas driven double effect absorption chiller/heater. The system working condition and operation limit condition is decided from the existing data which is analyzed and the conference with KOGAS. After the basic input variable and regular condition is established for heat cycle analysis, the simulation algorithm is set up and performance simulation program is coded according to the organized algorithm. The basic design of optimum system is completed from parametric study using developed simulation program and establishing the design variable range of developing object model. 20 refs., 30 figs., 9 tabs.

Effect of Ducted HPWH on Space-Conditioning and Water Heating Energy Use -- Central Florida Lab Home

Energy Technology Data Exchange (ETDEWEB)

Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States); Martin, Eric [Florida Solar Energy Center, Cocoa, FL (United States); Parker, Danny [Florida Solar Energy Center, Cocoa, FL (United States)

2016-11-01

The purpose of this research is to investigate the impact of ducted heat pump water heaters (HPWH's) on space conditioning and water heating energy use in residential applications. Two identical HPWH's, each of 60 gallon capacity were tested side by side at the Flexible Residential Test facility (FRTF) laboratories of the Florida Solar Energy Center (FSEC) campus in Cocoa, Florida. The water heating experiments were run in each test house from July 2014 until February 2015.

The CNEN Helium-Caesium Blow-Down MPD Facility and Experiments with a Prototype Duct

Energy Technology Data Exchange (ETDEWEB)

Bertolini, E.; Toschi, R. [CNEN, Frascati (Italy); Lindley, B. C. [C.A. Parsons and Co. Ltd (United Kingdom); Brown, R.; McNab, I. R. [International Research and Development Co. Ltd., Newcastle Upon Tyne (United Kingdom)

1966-11-15

The CNEN blow-down loop has been designed to study a helium-caesium MPD generator with particular regard to non-equilibrium ionization effects. An operating condition of the loop is: gas mass flow 0.2 kg/sec, seed fraction 1 at, wt.%, useful pulse duration 20 sec, stagnation temperature 2000 Degree-Sign K, stagnation pressure 5 atm abs, thermal power 1.6 MW, Mach number 0.6, magnetic field 4 Wb/m2, total impurity level less than 100 ppm. A sufficiently wide range of the stagnation conditions can be obtained with the present arrangement of the loop (temperature up to 2000*K, pressure from slightly sub-atmospheric to 6atmabs, gas mass flow from 50 g/sec to 400 g/sec, seed fraction from 0.1 to 2 at. wt.%. The storage heater is an alumina pebble bed electrically heated with tungsten elements and thermally insulated with zirconia fibre; the thermal capacity at 2000 Degree-Sign K is about 1000 MJ. Pure helium is obtained by evaporation of liquid helium at between 4.5 and 5 Degree-Sign K; liquid caesium is injected into a limited section of the pebble bed to provide a mixture of the two gases uniform in density and temperature. The duct is made of boron nitride (5 cm x 3 cm x 22 cm) with 25 pairs of tantalum electrodes whose geometry (electrode width 3 mm, segmentation pitch 9 mm) should prevent current leakage between adjacent electrodes; the duct walls and transfer can be pre-heated up to 1700 Degree-Sign K. A magnetic field of 4 Wb/m{sup 2} is obtained with a pulsed cryogenic magnet with pulse duration of 6 sec. Two series of experiments have been completed to assess the feasibility of the helium-caesium heating system and the generator duct. Heating system experiments, (a) Compatibility of alumina with tungsten, tantalum and caesium, with thermal cycling at 2000 Degree-Sign K; (b) Purification of zirconia fibre and its behaviour at high temperature, with thermal cycling at 2000 Degree-Sign K; (c) Capability of an alumina pebble bed of evaporating, heating and mixing

Laboratory Evaluation of Gas-Fired Tankless and Storage Water Heater Approaches to Combination Water and Space Heating

Energy Technology Data Exchange (ETDEWEB)

Kingston, T.; Scott, S.

2013-03-01

Homebuilders are exploring more cost effective combined space and water heating systems (combo systems) with major water heater manufacturers that are offering pre-engineered forced air space heating combo systems. In this project, unlike standardized tests, laboratory tests were conducted that subjected condensing tankless and storage water heater based combo systems to realistic, coincidental space and domestic hot water loads with the following key findings: 1) The tankless combo system maintained more stable DHW and space heating temperatures than the storage combo system. 2) The tankless combo system consistently achieved better daily efficiencies (i.e. 84%-93%) than the storage combo system (i.e. 81%- 91%) when the air handler was sized adequately and adjusted properly to achieve significant condensing operation. When condensing operation was not achieved, both systems performed with lower (i.e. 75%-88%), but similar efficiencies. 3) Air handlers currently packaged with combo systems are not designed to optimize condensing operation. More research is needed to develop air handlers specifically designed for condensing water heaters. 4) System efficiencies greater than 90% were achieved only on days where continual and steady space heating loads were required with significant condensing operation. For days where heating was more intermittent, the system efficiencies fell below 90%.

Compact Buried Ducts in a Hot-Humid Climate House

Energy Technology Data Exchange (ETDEWEB)

Mallay, D. [Home Innovation Research Labs, Upper Marlboro, MD (United States)

2016-01-01

A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval.

Energy efficiency and indoor thermal perception. A comparative study between radiant panel and portable convective heaters

Energy Technology Data Exchange (ETDEWEB)

Ali, Ahmed Hamza H.; Morsy, Mahmoud Gaber [Department of Mechanical Engineering, Faculty of Engineering, Assiut University, Assiut, 71516 (Egypt)

2010-11-15

This study investigates experimentally the thermal perception of indoor environment for evaluating the ability of radiant panel heaters to produce thermal comfort for space occupants as well as the energy consumption in comparison with conventional portable natural convective heaters. The thermal perception results show that, compared with conventional convection heater, a radiantly heated office room maintains a lower ambient air temperature while providing equal levels of thermal perception on the thermal dummy head as the convective heater and saves up to 39.1% of the energy consumption per day. However, for human subjects' vote experiments, the results show that for an environmentally controlled test room at outdoor environment temperatures of 0C and 5C, using two radiant panel heaters with a total capacity of 580 W leads to a better comfort sensation than the conventional portable natural convective heater with a 670 W capacity, with an energy saving of about 13.4%. In addition, for an outdoor environment temperature of 10C, using one radiant panel heater with a capacity of 290 W leads to a better comfort sensation than the conventional convection heater with a 670 W capacity, with an energy saving of about 56.7%. From the analytical results, it is found that distributing the radiant panel heater inside the office room, one on the wall facing the window and the other on the wall close to the window, provides the best operative temperature distribution within the room.

The results of air treatment process modeling at the location of the air curtain in the air suppliers and ventilation shafts

Directory of Open Access Journals (Sweden)

Nikolaev Aleksandr

2017-01-01

Full Text Available In the existing shaft air heater installations (AHI, that heat the air for air suppliers in cold seasons, a heater channel is used. Some parts of the air from the heater go to the channel, other parts are sucked through a pithead by the general shaft pressure drawdown formed by the main ventilation installation (MVI. When this happens, a mix of two air flows leads to a shaft heat regime violation that can break pressurization of intertubular sealers. The problem of energy saving while airing underground mining enterprises is also very important. The proposed solution of both tasks due to the application of an air curtain is described in the article. In cold seasons the air treatment process should be used and it is offered to place an air curtain in the air suppliers shaft above the place of interface of the calorifer channel to a trunk in order to avoid an infiltration (suction of air through the pithead. It’s recommended to use an air curtain in a ventilation shaft because it reduces external air leaks thereby improving energy efficiency of the MVI work. During the mathematical modeling of ventilation and air preparation process (in SolidWorks Flowsimulation software package it was found out that the use of the air curtain in the air supply shaft can increase the efficiency of the AHI, and reduce the electricity consumption for ventilation in the ventilation shaft.

The Energy Implications of Air-Side Fouling in Constant Air Volume HVAC Systems

Science.gov (United States)

Wilson, Eric J. H.

2011-12-01

This thesis examines the effect of air-side fouling on the energy consumption of constant air volume (CAV) heating, ventilating, and air conditioning (HVAC) systems in residential and small commercial buildings. There is a particular focus on evaluating the potential energy savings that may result from the remediation of such fouling from coils, filters, and other air system components. A computer model was constructed to simulate the behavior of a building and its duct system under various levels of fouling. The model was verified through laboratory and field testing and then used to run parametric simulations to examine the range of energy impacts for various climates and duct system characteristics. A sensitivity analysis was conducted to determine the impact of parameters like duct insulation, duct leakage, duct location, and duct design on savings potential. Duct system pressures, temperatures, and energy consumption for two houses were monitored for one month. The houses' duct systems, which were both in conditioned space, were given a full cleaning, and were then monitored for another month. The flow rates at the houses improved by 10% and 6%. The improvements were primarily due to installing a new filter, as both houses had only light coil fouling. The results indicate that there was negligible change in heating energy efficiency due to the system cleaning. The parametric simulation results are in agreement with the field experiment: for systems in all eight climates, with flowrates degraded by 20% or less, if ducts are located within the thermal zone, HVAC source energy savings from cleaning are negligible or even slightly negative. However, if ducts are outside the thermal zone, savings are in the 1 to 5% range. For systems with flowrates degraded by 40%, if ducts are within the thermal zone, savings from cleaning occurs only for air conditioning energy, up to 8% in climates like Miami, FL. If ducts are outside the thermal zone, savings occurs with both

14 CFR 23.859 - Combustion heater fire protection.

Science.gov (United States)

2010-01-01

... relief of any backfire that, if so restricted, could cause heater failure. (d) Heater controls: general. Provision must be made to prevent the hazardous accumulation of water or ice on or in any heater control... heater in case of leakage. (2) The region surrounding the heater, if the heater fuel system has fittings...

The effects of stroke length and Reynolds number on heat transfer to a ducted confined and semi-confined synthetic air jet

International Nuclear Information System (INIS)

Rylatt, D I; O'Donovan, T S

2014-01-01

Heat transfer to three configurations of ducted jet and un-ducted semiconfined jets is investigated experimentally. The influence of the jet operating parameters, stroke length (L 0 /D) and Reynolds (Re) number on the heat transferred to the jet is of particular interest. Heat transfer distributions to the jet are reported at H/D = 1 for a range of experimental parameters Re (1000 to 4000) and L 0 /D (5 to 20). Secondary and tertiary peaks are discernable in the heat transfer distributions across the range of parameters tested. It is shown that for a fixed Re varying the L 0 /D has little effect on the magnitude of the stagnation region heat transfer but does effect the position and magnitude of the secondary and tertiary peaks in the heat transfer distribution. It is also shown that for a fixed L 0 /D increasing the Re has a significant effect on the magnitude of the stagnation region heat transfer but has little impact on the position of the secondary and tertiary peaks in the heat transfer distributions. Ducting is added to the configuration to improve heat transfer by drawing cold air from a remote location into the jet flow. Ducting is shown to increase stagnation region and area averaged heat transfer across the range of jet parameters tested when compared with an un-ducted jets of equal confinement. Increasing the stroke length from L 0 /D = 5 to 20 for a Reynolds number of 2000 reduces the enhancement in stagnation region heat transfer provided by the ducting from 35% to 10%; the area averaged heat transfer provided by the ducting also changes from a 42% to a 21% enhancement. This is shown to be partly due to relative magnitude of the peaks in heat transfer outwith the stagnation region; at low stroke lengths, the difference in the magnitude of these peaks is large and reduces with increasing L 0 /D. It is also shown that as L 0 /D is increased the stagnation region heat transfer to the un-ducted jets increases while for the ducted jets stagnation region

Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

Science.gov (United States)

1980-01-01

The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

Science.gov (United States)

1980-07-01

The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

Collector Efficiency in Downward-Type Double-Pass Solar Air Heaters with Attached Fins and Operated by External Recycle

Directory of Open Access Journals (Sweden)

Chii-Dong Ho

2012-07-01

Full Text Available The collector efficiency in a downward-type double-pass external-recycle solar air heater with fins attached on the absorbing plate has been investigated theoretically. Considerable improvement in collector efficiency is obtainable if the collector is equipped with fins and the operation is carried out with an external recycle. Due to the recycling, the desirable effect of increasing the heat transfer coefficient compensates for the undesirable effect of decreasing the driving force (temperature difference of heat transfer, while the attached fins provide an enlarged heat transfer area. The order of performances in the devices of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

Low-Temperature Baseboard Heaters in Built Environments

Energy Technology Data Exchange (ETDEWEB)

Ploskic, Adnan

2010-10-15

The European Union has adopted a plan to decrease 20 % of total energy consumption through improved energy efficiency by 2020. One way of achieving this challenging goal may be to use efficient water-based heating systems supplied by heat pumps or other sustainable systems. The goal of this research was to analyze and improve the thermal performance of water-based baseboard heaters at low-temperature water supply. Both numerical (CFD) and analytical simulations were used to investigate the heat efficiency of the system. An additional objective of this work was to ensure that the indoor thermal comfort was satisfied in spaces served by such a low-temperature heating system. Analyses showed that it was fully possible to cover both transmission and ventilation heat losses using baseboard heaters supplied by 45 deg C water flow. The conventional baseboards, however, showed problems in suppressing the cold air down-flow created by 2.0 m high glazing and an outdoor temperature of -12 deg C. The draught discomfort at ankle level was slightly above the upper limit recommended by international and national standards. On the other hand, thermal baseboards with integrated ventilation air supply showed better ability to neutralize cold downdraught at the same height and conditions. Calculations also showed that the heat output from the integrated system with one ventilation inlet was approximately twice as high as that of the conventional one. The general conclusion from this work was that low temperature baseboards, especially with integrated ventilation air supply, are an efficient heating system and able to be combined with devices that utilize the low-quality sustainable energy sources such as heat pumps

78 FR 7394 - Notification of Proposed Production Activity; GE Appliances; Subzone 29C (Electric Water Heaters...

Science.gov (United States)

2013-02-01

..., freezers, apparel washing machines and dryers, electric ranges, and air-conditioners, under FTZ procedures...), fan motors, fans, filter/ dryers, expansion valves, accumulators, parts of electric water heaters...

14 CFR 25.859 - Combustion heater fire protection.

Science.gov (United States)

2010-01-01

..., could cause heater failure. (d) Heater controls; general. Provision must be made to prevent the hazardous accumulation of water or ice on or in any heater control component, control system tubing, or... leakage. (2) The region surrounding the heater, if the heater fuel system has fittings that, if they...

Analysis of the influence of operating conditions on fouling rates in fired heaters

International Nuclear Information System (INIS)

Morales-Fuentes, A.; Picón-Núñez, M.; Polley, G.T.; Méndez-Díaz, S.

2014-01-01

Fouling due to chemical reaction in preheat trains for the processing of crude oil plays a key role in the operation and maintenance costs and on greenhouse emissions to atmosphere in crude processing plants. A preheat train consists of a set of heat transfer units that provide the crude oil stream the required amount of thermal energy to reach its target temperature either by heat recovery or by direct firing. Fired heaters supply external high temperature heating through the burning of fuel which result in complex heat transfer processes due to the large temperature and pressure changes and vaporization that takes place inside the unit. In this work, a thermo-hydraulic analysis of the performance of fired heaters is carried out through the application of commercial software to solve the mathematical models using finite difference methods; the analysis is applied to the crude side of a vertical fired heater in order to evaluate the impact of process conditions such as throughput and crude inlet temperature (CIT) on the fouling that take place at the early stages of operation. Using a fouling rate model based on thermo-hydraulic parameters, fouling rates are predicted assuming steady state operation and clean conditions. Although variations in process conditions are known to influence fouling rates, little work has been done on the subject. In this work excess air and steam injection are studied as a means to mitigate fouling. Results show that throughput reduction brings about a marked increase in the fouling rates. A decrease in CIT affects only the convection zone and it is found that this effect is negligible. In terms of excess air, it is found that although it affects negatively the heater efficiency it can be used to balance heat transfer between the convection and radiation zone in a way that fouling rates are reduced; however this strategy should be considered right from the design stage. Finally it is observed that steam injection is an effective method

Anatomic relationship of intrahepatic bile ducts to portal veins revisited

International Nuclear Information System (INIS)

Bret, P.M.; Stempel, J.; Atri, M.; Lough, J.O.; Illescas, F.F.

1987-01-01

It is well accepted that intrahepatic bile ducts lie in front of corresponding portal vein branches. Since the authors' clinical experience with US was different, they studied 18 normal necropsy cadaver livers. The common bile duct, main portal vein, and hepatic artery were cannulated and injected respectively with air, dilute contrast medium, and mineral oil. The livers were then examined in anatomic position with CT. In the left lobe of the liver, the bile ducts were anterior to the portal vein in seven cases, posterior in seven cases, and were tortuous both anterior and posterior in three cases. In the right lobe, the bile ducts were anterior in nine cases, posterior in five cases, tortuous in one case, and not seen in two cases. In the porta hepatis, the bile ducts were anterior in eight cases, posterior in one case, tortuous in five cases, and not seen in three cases. Histologic specimens confirmed the anterior and posterior location of the bile ducts relative to the portal veins. In conclusion, intrahepatic bile ducts can be either anterior or posterior to the corresponding portal vein branches

Parallel heater system for subsurface formations

Science.gov (United States)

Harris, Christopher Kelvin [Houston, TX; Karanikas, John Michael [Houston, TX; Nguyen, Scott Vinh [Houston, TX

2011-10-25

A heating system for a subsurface formation is disclosed. The system includes a plurality of substantially horizontally oriented or inclined heater sections located in a hydrocarbon containing layer in the formation. At least a portion of two of the heater sections are substantially parallel to each other. The ends of at least two of the heater sections in the layer are electrically coupled to a substantially horizontal, or inclined, electrical conductor oriented substantially perpendicular to the ends of the at least two heater sections.

Environmental aspects of the use of materials for solar water heaters

International Nuclear Information System (INIS)

Van der Leun, C.J.; De Jager, D.

1994-10-01

The study on the title subject has been carried out in order to apply the results in new designs and to improve the production of solar water heating systems. Attention is paid to solar water heaters that are under development and solar water heaters that are commercially available in the Netherlands. Use has been made of a IVAM-developed product analysis method. For seven solar water heater concepts, that were on the market or under development in the Netherlands in 1992, the applied amounts of materials have been inventorized. Data on the environmental effects of the production of these materials are outlined and aggregated on the level of the components and the systems. Based on those data, environmental profiles are drafted, comprising 'effect scores' on 9 environmental criteria. However, the environmental 'effect scores' are not reliable enough to determine the most important factors in order to identify options to reduce the negative environmental effects. Data on the energy consumption of the production of relevant materials are available and reliable. The solar water heaters, considered in this report, do not show large differences for that matter. It appears that the amounts of air pollution, water pollution and waste flow from the production of materials for solar water heaters are no reasons to further reduce environmental effects of the production. It is recommended to focus on the reduction of material quantities and to increase the quantity of recycled material. Also it is recommended that manufacturers of solar boilers set up a take-back system. 43 tabs., 1 appendix, 56 refs

Experiments on MHD Generation with ETL Mark II

Energy Technology Data Exchange (ETDEWEB)

Mori, F.; Fushimi, K.; Ikeda, S. [Electrotechnical Laboratory, Ministry of International Trade and Industry, Tokyo (Japan)

1968-11-15

The experimental results of the ETL Mark II combustion-driven Faraday-type MHD generator are described. The cross-sectional area of the generator duct is 9 x 11 cm{sup 2} at the inlet and 9 x 25 cm{sup 2} at the outlet. The insulating wall of the duct is made of magnesia and the electrode of carbon. There are 30 electrode pairs. The length of the duct is 120 cm and the width of an electrode is 3 cm. The combustion chamber is of cylindrical shape, and from the bottom of the chamber the fuel, the seeding material and the oxidizer are injected. The fuel is diesel oil and the seeding material potassium hydroxide dissolved in methyl alcohol. The oxidizer is oxygen, but air or oxygen-enriched air can be used. In the latter case, the air is pre-heated up to about 1700 Degree-Sign K by a pebble heater containing alumina pebbles to about 7 tons in weight. The heater, which incorporates a propane burner, supplies the pre-heated air to the combustion chamber at a pressure of 5 atm(g) and at a rate of 2.6 kg/s for a period of 5 minutes. The maximum temperature of the air is 1700 Degree-Sign K at the outlet of the heater and the temperature falls by 20 Degree-Sign K after 5 minutes. If pre-heated air (or oxygen-enriched air) is used as the oxidizer, only the methyl alcohol containing the dissolved potassium hydroxide is used as the fuel. The electromagnet, which has an iron core of about 80 tons weight, can generate a maximum flux density of 3.4 T with an air gap of 16 cm. The exciting ampere-turns of the copper coil are then 1.4 x 10{sup 6} AT. The experimental procedure with the generator is as follows. The combustion chamber and the generator duct are heated to about 1300 Degree-Sign K by the combustion products of propane and air, and then the electromagnet is excited and the fuel, oxidizer and seeding material are injected. The load.resistances of each of the 30 electrode pairs are varied and the output voltages and the currents of every second electrode pair are measured

Effect of Fuel Wobbe Number on Pollutant Emissions from Advanced Technology Residential Water Heaters: Results of Controlled Experiments

Energy Technology Data Exchange (ETDEWEB)

Rapp, Vi H.; Singer, Brett C.

2014-03-01

The research summarized in this report is part of a larger effort to evaluate the potential air quality impacts of using liquefied natural gas in California. A difference of potential importance between many liquefied natural gas blends and the natural gas blends that have been distributed in California in recent years is the higher Wobbe number of liquefied natural gas. Wobbe number is a measure of the energy delivery rate for appliances that use orifice- or pressure-based fuel metering. The effect of Wobbe number on pollutant emissions from residential water heaters was evaluated in controlled experiments. Experiments were conducted on eight storage water heaters, including five with “ultra low-NO{sub X}” burners, and four on-demand (tankless) water heaters, all of which featured ultra low-NO{sub X} burners. Pollutant emissions were quantified as air-free concentrations in the appliance flue and fuel-based emission factors in units of nanogram of pollutant emitter per joule of fuel energy consumed. Emissions were measured for carbon monoxide (CO), nitrogen oxides (NO{sub X}), nitrogen oxide (NO), formaldehyde and acetaldehyde as the water heaters were operated through defined operating cycles using fuels with varying Wobbe number. The reference fuel was Northern California line gas with Wobbe number ranging from 1344 to 1365. Test fuels had Wobbe numbers of 1360, 1390 and 1420. The most prominent finding was an increase in NO{sub X} emissions with increasing Wobbe number: all five of the ultra low-NO{sub X} storage water heaters and two of the four ultra low-NO{sub X} on-demand water heaters had statistically discernible (p<0.10) increases in NO{sub X} with fuel Wobbe number. The largest percentage increases occurred for the ultra low-NO{sub X} water heaters. There was a discernible change in CO emissions with Wobbe number for all four of the on-demand devices tested. The on-demand water heater with the highest CO emissions also had the largest CO increase

Study on particle deposition in vertical square ventilation duct flows by different models

International Nuclear Information System (INIS)

Zhang Jinping; Li Angui

2008-01-01

A proper representation of the air flow in a ventilation duct is crucial for adequate prediction of the deposition velocity of particles. In this paper, the mean turbulent air flow fields are predicted by two different numerical models (the Reynolds stress transport model (RSM) and the realizable k-εmodel). Contours of mean streamwise velocity deduced from the k-ε model are compared with those obtained from the Reynolds stress transport model. Dimensionless deposition velocities of particles in downward and upward ventilation duct flows are also compared based on the flow fields presented by the two different numerical models. Trajectories of the particles are tracked using a one way coupling Lagrangian eddy-particle interaction model. Thousands of individual particles are released in the represented flow, and dimensionless deposition velocities are evaluated for the vertical walls in fully developed smooth vertical downward and upward square duct flows generated by the RSM and realizable k-ε model. The effects of particle diameter, dimensionless relaxation time, flow direction and air speed in vertical upward and downward square duct flows on the particle deposition velocities are discussed. The effects of lift and gravity on the particle deposition velocities are evaluated in vertical flows presented by the RSM. It is shown that the particle deposition velocities based on the RSM and realizable k-εmodel have subtle differences. The flow direction and the lift force significantly affect the particle deposition velocities in vertical duct flows. The simulation results are compared with earlier experimental data and the numerical results for fully developed duct flows. It is shown that the deposition velocities predicted are in agreement with the experimental data and the numerical results

Prototype heater test of the environment around a simulated waste package

International Nuclear Information System (INIS)

Ramirez, A.L.; Buscheck, T.A.; Carlson, R.; Daily, W.; Latorre, V.R.; Lee, K; Lin, Wunan; Mao, Nai-hsien; Towse, D.; Ueng, Tzou-Shin; Watwood, D.

1991-01-01

This paper presents selected results obtained during the 301 day duration of the Prototype Engineered Barrier System Field Test (PEBSFT) performed in G-Tunnel within the Nevada Test Site. The test described is a precursor to the Engineered Barrier Systems Field Tests (EBSFT) planned for the Exploratory Shaft Facility in Yucca Mountain. The EBSFT will consist of in situ tests of the geohydrologic and geochemical environment in the near field (within a few meters) of heaters emplaced in welded tuff to simulate the thermal effects of waste packages. The paper discusses the evolution of hydrothermal behavior during the prototype test, including rock temperatures, changes in rock moisture content, air permeability of fractures and gas-phase humidity in the heater borehole

One-year assessment of a solar space/water heater--Clinton, Mississippi

Science.gov (United States)

1981-01-01

Unit called "System 4" integrated into space-heating and hot-water systems of dormitory satisfied 32 percent of building heat load. System 4 includes flat-plate air collectors, circulation blowers, rock storage bed with heat exchanger, two hot water tanks, and auxiliary heaters. Report describes performance of system and subsystems, operating-energy requirements and savings, and performance parameters.

Particle loading rates for HVAC filters, heat exchangers, and ducts.

Science.gov (United States)

Waring, M S; Siegel, J A

2008-06-01

The rate at which airborne particulate matter deposits onto heating, ventilation, and air-conditioning (HVAC) components is important from both indoor air quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle mass loading rates for residential and commercial filters, heat exchangers (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted mass loading rates allow for the assessment of pressure drop and indoor air quality consequences that result from particle mass loading onto HVAC system components.

Thermal Hydraulic Performance in a Solar Air Heater Channel with Multi V-Type Perforated Baffles

Directory of Open Access Journals (Sweden)

Anil Kumar

2016-07-01

Full Text Available This article presents heat transfer and fluid flow characteristics in a solar air heater (SAH channel with multi V-type perforated baffles. The flow passage has an aspect ratio of 10. The relative baffle height, relative pitch, relative baffle hole position, flow attack angle, and baffle open area ratio are 0.6, 8.0, 0.42, 60°, and 12%, respectively. The Reynolds numbers considered in the study was in the range of 3000–10,000. The re-normalization group (RNG k-ε turbulence model has been used for numerical analysis, and the optimum relative baffle width has been investigated considering relative baffle widths of 1.0–7.0.The numerical results are in good agreement with the experimental data for the range considered in the study. Multi V-type perforated baffles are shown to have better thermal performance as compared to other baffle shapes in a rectangular passage. The overall thermal hydraulic performance shows the maximum value at the relative baffle width of 5.0.

High-temperature MEMS Heater Platforms: Long-term Performance of Metal and Semiconductor Heater Materials

Directory of Open Access Journals (Sweden)

Theodor Doll

2006-04-01

Full Text Available Micromachined thermal heater platforms offer low electrical power consumptionand high modulation speed, i.e. properties which are advantageous for realizing non-dispersive infrared (NDIR gas- and liquid monitoring systems. In this paper, we report oninvestigations on silicon-on-insulator (SOI based infrared (IR emitter devices heated byemploying different kinds of metallic and semiconductor heater materials. Our resultsclearly reveal the superior high-temperature performance of semiconductor over metallicheater materials. Long-term stable emitter operation in the vicinity of 1300 K could beattained using heavily antimony-doped tin dioxide (SnO2:Sb heater elements.

Bile Duct Exploration

Science.gov (United States)

... Home / Health Library / Diagnostics & Testing / Bile Duct Exploration Bile Duct Exploration Common bile duct exploration is a ... Test Details Results and Follow-Up What is bile, and what is bile duct exploration? Bile is ...

Indoor air quality study of forty east Tennessee homes

Energy Technology Data Exchange (ETDEWEB)

Hawthorne, A.R.; Gammage, R.B.; Dudney, C.S.; Hingerty, B.E.; Schuresko, D.D.; Parzyck, D.C.; Womack, D.R.; Morris, S.A.; Westley, R.R.; White, D.A.

1984-12-01

Over a one-year period, measurements of indoor air pollutants (CO/sub x/, NO/sub x/, formaldehyde, volatile organics, particulates, and radon) were made in 40 homes in East Tennessee. The houses were of various ages with different types of insulation and heating. Over one-half of the houses exceeded the ASHRAE indoor ceiling guideline of 0.1 ppM for formaldehyde on at least one occasion. Over the duration of the study, older houses averaged 0.04 ppM of formaldehyde while houses less than 5 years old averaged 0.08 ppM (P < 0.01). The highest concentration of formaldehyde measured was 0.4 ppM in a new home. Diurnal and seasonal fluctuations in levels of formaldehyde in some homes were as much as twofold and tenfold, respectively. The highest levels of formaldehyde were usually recorded during summer months. The concentration in indoor air of various organics was at least tenfold higher than in outdoor air. Carbon monoxide and nitrgen oxides were usually <2 and <0.02 ppM, respectively, except when gas stoves or kerosene space heaters were operating, or when a car was running in the garage. In 30% of the houses, the annual indoor guideline for radon, 4 pCi/L, was exceeded. The mean radon level in houses built on the ridgelines was 4.4 pCi/L, while houses located in the valleys had a mean level of 1.7 pCi/L (P < 0.01). The factor having the most impact on infiltration was operation of the central duct fan of the heating, ventilation, and air conditioning system. The mean rate of air exchange increased from 0.39 to 0.74 h/sup -1/ when the duct fan was operated (measurements prior to December 1982). This report presents the study design and implementation, describes the monitoring protocols, and provides a complete set of the data collected during the project. 25 references, 29 figures, 42 tables.

Heater Validation for the NEXT-C Hollow Cathodes

Science.gov (United States)

Verhey, Timothy R.; Soulas, George C.; Mackey, Jonathan A.

2018-01-01

Swaged cathode heaters whose design was successfully demonstrated under a prior flight project are to be provided by the NASA Glenn Research Center for the NEXT-C ion thruster being fabricated by Aerojet Rocketdyne. Extensive requalification activities were performed to validate process controls that had to be re-established or revised because systemic changes prevented reuse of the past approaches. A development batch of heaters was successfully fabricated based on the new process controls. Acceptance and cyclic life testing of multiple discharge and neutralizer sized heaters extracted from the development batch was initiated in August, 2016, with the last heater completing testing in April, 2017. Cyclic life testing results substantially exceeded the NEXT-C thruster requirement as well as all past experience for GRC-fabricated units. The heaters demonstrated ultimate cyclic life capability of 19050 to 33500 cycles. A qualification batch of heaters is now being fabricated using the finalized process controls. A set of six heaters will be acceptance and cyclic tested to verify conformance to the behavior observed with the development heaters. The heaters for flight use will be then be provided to the contractor from the remainder of the qualification batch. This paper summarizes the fabrication process control activities and the acceptance and life testing of the development heater units.

An evaluation of damping ratios for HVAC duct systems using vibration test data

International Nuclear Information System (INIS)

Gunyasu, K.; Horimizu, Y.; Kawakami, A.; Iokibe, H.; Yamazaki, T.

1988-01-01

The function of Heating Ventilating Air Conditioning (HVAC) systems must be maintained including HVAC duct systems to keep the operation of safety-related equipment in nuclear power plants during earthquake excitations. Therefore, it is important to carry out seismic design for HVAC duct systems. In the previous aseismic design for HVAC duct systems, the 0.5% damping ratio has been used in Japan. In recent years, vibration tests, held on actual duct systems in nuclear power plants and mockup duct systems were performed in order to investigate damping ratios for HVAC duct systems. Based on the results, it was confirmed that the damping ratio for HVAC duct systems, evaluated from these tests, were much greater than the 0.5% damping ratio used in the previous aseismic design of Japan. The new damping ratio in aseismic design was proposed to be 2.5%. The present paper describes the results of the above mentioned investigation

Natural Flow Air Cooled Photovoltaics

Science.gov (United States)

Tanagnostopoulos, Y.; Themelis, P.

2010-01-01

Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. We performed experiments using a prototype based on three silicon photovoltaic modules placed in series to simulate a typical sloping building roof with photovoltaic installation. In this system the air flows through a channel on the rear side of PV panels. The potential for increasing the heat exchange from the photovoltaic panel to the circulating air by the addition of a thin metal sheet (TMS) in the middle of air channel or metal fins (FIN) along the air duct was examined. The operation of the device was studied with the air duct closed tightly to avoid air circulation (CLOSED) and the air duct open (REF), with the thin metal sheet (TMS) and with metal fins (FIN). In each case the experiments were performed under sunlight and the operating parameters of the experimental device determining the electrical and thermal performance of the system were observed and recorded during a whole day and for several days. We collected the data and form PV panels from the comparative diagrams of the experimental results regarding the temperature of solar cells, the electrical efficiency of the installation, the temperature of the back wall of the air duct and the temperature difference in the entrance and exit of the air duct. The comparative results from the measurements determine the improvement in electrical performance of the photovoltaic cells because of the reduction of their temperature, which is achieved by the naturally circulating air.

Experimental Study of the Slit Spacing and Bed Height on the Thermal Performance of Slit-Glazed Solar Air Heater

Directory of Open Access Journals (Sweden)

Seyyed Mahdi Taheri Mousavi

2017-01-01

Full Text Available The thermal performances of three slit-glazed solar air heaters (SGSAHs were investigated experimentally. Three SGSAHs with different bed heights (7 cm, 5 cm, and 3 cm were fabricated with multiple glass panes used for glazing. The length, width, and thickness of each pane were 154 cm, 6 cm, and 0.4 cm, respectively. Ambient air was continuously withdrawn through the gaps between the glass panes by fans. The experiments were conducted for four different gap distances between the glass panes (0.5 mm, 1 mm, 2 mm, and 3 mm and the air mass flow rate was varied between 0.014 kg/s and 0.057 kg/s. The effects of air mass flux on the outlet temperature and thermal efficiency were studied. For the SGSAH with bed height of 7 cm and glass pane gap distance of 0.5 mm, the highest efficiency was obtained as 82% at a mass flow rate of 0.057 kg/s and the air temperature difference between the inlet and the outlet (∆T was maximum (27°C when the mass flow rate was least. The results demonstrate that for lower mass flow rates and larger gaps, the performance of SGSAH with a bed height of 3 cm was better compared to that of others. However, for higher mass flow rates, the SGSAH with 7 cm bed height performed better.

Heater for Combustible-Gas Tanks

Science.gov (United States)

Ingle, Walter B.

1987-01-01

Proposed heater for pressurizing hydrogen, oxygen, or another combustible liquid or gas sealed in immersion cup in pressurized tank. Firmly supported in finned cup, coiled rod transfers heat through liquid metal to gas tank. Heater assembly welded or bolted to tank flange.

The effect of cleanliness control during installation work on the amount of accumulated dust in ducts of new HVAC installations.

Science.gov (United States)

Holopainen, R; Tuomainen, M; Asikainen, V; Pasanen, P; Säteri, J; Seppänen, O

2002-09-01

The aim of this study was to evaluate the amount of dust in supply air ducts in recently installed ventilation systems. The samples for the determination of dust accumulation were collected from supply air ducts in 18 new buildings that have been constructed according to two different cleanliness control levels classified as category P1 (low oil residues and protected against contaminations) and category P2, as defined in the Classification of Indoor Climate, Construction and Building Materials. In the ducts installed according to the requirements of cleanliness category P1 the mean amount of accumulated dust was 0.9 g/m2 (0.4-2.9 g/m2), and in the ducts installed according to the cleanliness category P2 it was 2.3 g/m2 (1.2-4.9 g/m2). A significant difference was found in the mean amounts of dust between ducts of categories P1 and P2 (P < 0.008). The cleanliness control procedure in category P1 proved to be a useful and effective tool for preventing dust accumulation in new air ducts during the construction process. Additionally, the ducts without residual oil had lower amounts of accumulated dust indicating that the demand for oil free components in the cleanliness classification is reasonable.

Optimization of thermal performance of a smooth flat-plate solar air heater using teaching–learning-based optimization algorithm

Directory of Open Access Journals (Sweden)

R. Venkata Rao

2015-12-01

Full Text Available This paper presents the performance of teaching–learning-based optimization (TLBO algorithm to obtain the optimum set of design and operating parameters for a smooth flat plate solar air heater (SFPSAH. The TLBO algorithm is a recently proposed population-based algorithm, which simulates the teaching–learning process of the classroom. Maximization of thermal efficiency is considered as an objective function for the thermal performance of SFPSAH. The number of glass plates, irradiance, and the Reynolds number are considered as the design parameters and wind velocity, tilt angle, ambient temperature, and emissivity of the plate are considered as the operating parameters to obtain the thermal performance of the SFPSAH using the TLBO algorithm. The computational results have shown that the TLBO algorithm is better or competitive to other optimization algorithms recently reported in the literature for the considered problem.

14 CFR 29.859 - Combustion heater fire protection.

Science.gov (United States)

2010-01-01

... relief of any backfire that, if so restricted, could cause heater failure. (d) Heater controls; general. There must be means to prevent the hazardous accumulation of water or ice on or in any heater control... malfunctioning; or (ii) Allow flammable fluids or vapors to reach the heater in case of leakage. (2) Each part of...

Numerical analysis of the influence of spherical turbulence generators on heat transfer enhancement of flat plate solar air heater

International Nuclear Information System (INIS)

Manjunath, M.S.; Karanth, K.Vasudeva; Sharma, N.Yagnesh

2017-01-01

This paper presents the influence of spherical turbulence generators on thermal efficiency and thermohydraulic performance of flat plate solar air heater. The analysis is carried out for the Reynolds number range of 4000–25000. The thermal performance is investigated for various diameter (D) of sphere consisting of 5,10,15,20 and 25 mm and relative roughness pitch (P/D) of 3, 6 and 12. The simulation is carried out using solar insolation as heat input at 12 noon conditions for the global position of Manipal (74.786°E, 13.343°N) obtained through the solar load model, a feature available in the software tool used for the analysis and Discrete Ordinates radiation model is used to compute the radiation heat interactions within the computational domain. The CFD results for the base model are validated against experimental results and are found to have good agreement. The thermal efficiency is found to increase with increasing sphere diameter and reducing relative roughness pitch. The maximum average percentage increase in thermal efficiency is found to be about 23.4% as compared to the base model for D = 25 mm and P/D = 3. The highest increase in the Nusselt number is found to be 2.5 times higher as compared to the base model for D = 25 mm and P/D = 3 at Re = 23560. The analysis shows that the relative roughness pitch and size of the spherical turbulator have significant influence on the thermohydraulic performance of solar air heater. - Highlights: • Spherical turbulators used create intense turbulent mixing in the vicinity of absorber. • Nusselt number peaks on the upstream surface of spherical turbulators. • Peak thermal efficiency occurs at lower pitch and higher diameter conditions. • Higher diameter and lower pitch values also impose greater pumping power penalty. • Diameter and pitch of spherical turbulator strongly influence the effective efficiency.

Thermal behavior of the duct applied functionally graded material

Energy Technology Data Exchange (ETDEWEB)

Park, Jung Sun; Yoon, Dong Young; Im, Jong Bin [Hankuk Aviation Univ., Goyang (Korea, Republic of)

2004-07-01

In Unmanned Aerial Vehicles (UAV), the high temperature results from friction among the air, combustion of fuel in engine and combustion gas of a nozzle. The high temperature may cause serious damages in UAV structure. The Functionally Graded Material(FGM) is chosen as a material of the engine duct structure. Thermal stress analysis of FGM is performed in this paper. FGM is composed of two constituent materials that are mixed up according to the specific volume fraction distribution in order to withstand high temperature. Therefore, hoop stress, axial stress and shear stress of duct with 2 layers, 4 layers and 8 layers FGM are compared and analyzed respectively. In addition, the creep behavior of FGM used in duct structure of an engine is analyzed for better understanding of FGM characteristics.

49 CFR 179.12 - Interior heater systems.

Science.gov (United States)

2010-10-01

... Design Requirements § 179.12 Interior heater systems. (a) Interior heater systems shall be of approved design and materials. If a tank is divided into compartments, a separate system shall be provided for... 49 Transportation 2 2010-10-01 2010-10-01 false Interior heater systems. 179.12 Section 179.12...

Laboratory Evaluation of Gas-Fired Tankless and Storage Water Heater Approaches to Combination Water and Space Heating

Energy Technology Data Exchange (ETDEWEB)

Kingston, T. [Gas Technology Inst., Des Plaines, IL (United States); Scott, S. [Gas Technology Inst., Des Plaines, IL (United States)

2013-03-01

Homebuilders are exploring more cost-effective combined space and water heating systems (combo systems) with major water heater manufacturers that are offering pre-engineered forced air space heating combo systems. In this project, unlike standardized tests, laboratory tests were conducted that subjected condensing tankless and storage water heater based combo systems to realistic, coincidental space and domestic hot water loads and found that the tankless combo system maintained more stable DHW and space heating temperatures than the storage combo system, among other key findings.

Electrical heaters for thermo-mechanical tests at the Stripa mine

International Nuclear Information System (INIS)

Burleigh, R.H.; Binnall, E.P.; DuBois, A.O.; Norgren, D.U.; Ortiz, A.R.

1979-01-01

Electrical heaters were installed at the Stripa mine in Sweden to simulate the heat flux expected from canisters containing nuclear waste. Three heater types were designed and fabricated: two full scale heaters, 2.6 m in length and 324 mm in diameter, supplying a maximum power output of 5 kW; eight peripheral heaters of 25 mm diameter, supplying 1.1 kW; and eight time scale heaters, one-third the size and power of the full scale heaters. The heater power can be monitored by panel meters as well as by a computer-based data acquisition system. Both the controller and the heater were designed with a high degree of redundancy in case of component failure. Auxiliary items were provided with the heaters to monitor borehole decrepitation and heater temperature, and to dewater the heater holes. This report describes the above systems and relates experience gained during testing, installation, and operation

Building America Case Study: Compact Buried Ducts in a Hot-Humid Climate House, Lady's Island, South Carolina

Energy Technology Data Exchange (ETDEWEB)

2016-02-01

A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely on encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences, 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs, and 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.

Are Ducted Mini-Splits Worth It?

Energy Technology Data Exchange (ETDEWEB)

Winkler, Jonathan M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Maguire, Jeffrey B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Metzger, Cheryn E. [Pacific Northwest National Laboratory; Zhang, Jason [Pacific Northwest National Laboratory

2018-02-01

Ducted mini-split heat pumps are gaining popularity in some regions of the country due to their energy-efficient specifications and their ability to be hidden from sight. Although product and install costs are typically higher than the ductless mini-split heat pumps, this technology is well worth the premium for some homeowners who do not like to see an indoor unit in their living area. Due to the interest in this technology by local utilities and homeowners, the Bonneville Power Administration (BPA) has funded the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL) to develop capabilities within the Building Energy Optimization (BEopt) tool to model ducted mini-split heat pumps. After the fundamental capabilities were added, energy-use results could be compared to other technologies that were already in BEopt, such as zonal electric resistance heat, central air source heat pumps, and ductless mini-split heat pumps. Each of these technologies was then compared using five prototype configurations in three different BPA heating zones to determine how the ducted mini-split technology would perform under different scenarios. The result of this project was a set of EnergyPlus models representing the various prototype configurations in each climate zone. Overall, the ducted mini-split heat pumps saved about 33-60% compared to zonal electric resistance heat (with window AC systems modeled in the summer). The results also showed that the ducted mini-split systems used about 4% more energy than the ductless mini-split systems, which saved about 37-64% compared to electric zonal heat (depending on the prototype and climate).

Solar water heaters in Taiwan

International Nuclear Information System (INIS)

Chang, K.; Lee, T.; Chung, K.

2006-01-01

Solar water heater has been commercialized during the last two decades in Taiwan. The government initiated the incentive programs during 1986-1991 and 2000-2004. This created an economic incentive for the end-users. The total area of solar collectors installed was more than one million square meters. The data also show that most of the solar water heaters are mainly used by the domestic sector for hot water production (about 97%). The regional popularization analysis indicates limited installation of solar water heaters in the northern district. In the eastern district and remote islands, the problems of climatic conditions and availability of localized installers/dealers are addressed. (author)

Solar Water-Heater Design Package

Science.gov (United States)

1982-01-01

Information on a solar domestic-hot water heater is contained in 146 page design package. System consists of solar collector, storage tanks, automatic control circuitry and auxiliary heater. Data-acquisition equipment at sites monitors day-by-day performance. Includes performance specifications, schematics, solar-collector drawings and drawings of control parts.

Adaptive individual-cylinder thermal state control using intake air heating for a GDCI engine

Science.gov (United States)

Roth, Gregory T.; Sellnau, Mark C.

2016-08-09

A system for a multi-cylinder compression ignition engine includes a plurality of heaters, at least one heater per cylinder, with each heater configured to heat air introduced into a cylinder. Independent control of the heaters is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the heater for that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder compression ignition engine, including determining a combustion parameter for combustion taking place in a cylinder of the engine and controlling a heater configured to heat air introduced into that cylinder, is also provided.

Is your electric process heater safe?

Energy Technology Data Exchange (ETDEWEB)

Tiras, C.S.

2000-04-01

Over the past 35 years, electric process heaters (EPHs) have been used to heat flowing fluids in different sectors of the energy industry: oil and gas exploration and production, refineries, petrochemical plants, pipeline compression facilities and power-generation plants. EPHs offer several advantages over fired heaters and shell-and-tube exchangers, which have been around for many years, including: smaller size, lighter weight, cleaner operation, lower capital costs, lower maintenance costs, no emissions or leakage, better control and improved safety. However, while many industrial standards have addressed safety concerns of fired heaters and shell-and-tube exchangers (API, TEMA, NFPA, OSHA and NEC), no standards address EPHs. The paper presents a list of questions that plant operators need to ask about the safety of their electric process heaters. The answers are also given.

Premixed CH4-Air Flame Structure Characteristic and Flow Behavior Induced by Obstacle in an Open Duct

Directory of Open Access Journals (Sweden)

DengKe Li

2015-01-01

Full Text Available To study the fuel gas combustion hazards, the methane/air flame structure and flow characteristic in an open duct influenced by a rectangular obstacle were explored by experiment and realizable k-∊ model (RKE. In the test, the high-speed schlieren photography technology and dynamic detection technology were applied to record the flame propagation behavior. Meanwhile, the interaction between flame front and flame flow field induced by the obstacle was disclosed. In addition, the laminar-turbulence transition was also taken into consideration. The RKE and eddy dissipation concept (EDC premixed combustion model were applied to obtain an insight into the phenomenon of flow change and wrinkle appearing, which potently explained the experimental observations. As a result, the obstacle blocked the laminar flame propagation velocity and increased pressure a little in an open duct. Some small-scale vortices began to appear near the obstacle, mainly due to Kelvin-Helmholtz instability (KHI, and gradually grew into large-scale vortices, which led to laminar-turbulent transition directly. The vortices thickened the reaction area and hastened the reaction rate; reversely, the higher reaction rate induced larger vortices. The RKE model result fitted the test data well and explained the wrinkle forming mechanism of two special vortices in the case.

Air conditioning device for pool facilities in nuclear power plant buildings

International Nuclear Information System (INIS)

Taruishi, Yoshiaki; Ishida, Seiji.

1981-01-01

Purpose: To improve the temperature and humidity conditions for the working circumstance, prevent condensations on the wall surface and enable the reduction in the irradiation exposure to workers. Constitution: Air intake ports are provided on the side wall of a fuel storage pool or an equipment installation pool above the water level and connected by way of their exhaust ducts to the exhaust ducts of an air ventilation system. While on the other hand, air feed ducts having horizontally opened blowing ports and air exhaust ducts having horizontally opened exhaust ports above and in adjacent to the air feed ducts are provided on the side walls of the pool buildings at the height near the floor level. With this structure, fresh outdoor airs blown out horizontally from the blowing ports provided near the floor level can improve the temperature and humidity conditions of the working circumstance for the workers working on the floor. Further, an air clean up device is provided to the feed and exhaust systems for clean up the feed and exhaust airs. (Furukawa, Y.)

Outlook for solar water heaters in Taiwan

International Nuclear Information System (INIS)

Chang, Keh-Chin; Lee, Tsong-Sheng; Chung, Kung-Ming; Lin, Wei-Min

2008-01-01

The share of indigenous energy supply continuously decreases over the last two decades in Taiwan. The development and use of renewable energy sources and technologies are becoming vital for the management of energy supply and demand. For promotion of solar water heaters, the incentive programs were firstly initiated in the period of 1986-1991 and re-initiated from 2000 to the present. These programs create an economic incentive for the end users and have a drastic effect on the popularization of solar water heaters. To further promote solar water heaters during the current incentive program period, several key factors are addressed. In addition to the cost of solar water heaters and energy price index, the potential market of solar water heaters in Taiwan is associated with the climatic conditions, population structure, urbanization, building type of housing and status of new construction. (author)

Outlook for solar water heaters in Taiwan

Energy Technology Data Exchange (ETDEWEB)

Chang, Keh-Chin [Department of Aeronautical and Astronautical Engineering, National Cheng Kung University, Kueijen, Tainan, Taiwan 711 (China); Lee, Tsong-Sheng; Chung, Kung-Ming [Aerospace Science and Technology Research Center, National Cheng Kung University, Kueijen, Tainan, Taiwan 711 (China); Lin, Wei-Min [Tainan University of Technology (China)

2008-01-15

The share of indigenous energy supply continuously decreases over the last two decades in Taiwan. The development and use of renewable energy sources and technologies are becoming vital for the management of energy supply and demand. For promotion of solar water heaters, the incentive programs were firstly initiated in the period of 1986-1991 and re-initiated from 2000 to the present. These programs create an economic incentive for the end users and have a drastic effect on the popularization of solar water heaters. To further promote solar water heaters during the current incentive program period, several key factors are addressed. In addition to the cost of solar water heaters and energy price index, the potential market of solar water heaters in Taiwan is associated with the climatic conditions, population structure, urbanization, building type of housing and status of new construction. (author)

Buffer mass test - Heater design and operation

International Nuclear Information System (INIS)

Nilsson, J.; Ramqvist, G.; Pusch, R.

1984-06-01

The nuclear waste is assumed to be contained in cylindrical metal canisters which will be inserted in deposition holes. Heat is generated as a result of the continuing decay of the radioactive waste and in the Buffer Mass Test (BMT) the heat flux expected from such canisters was simulated by the use of six electric heaters. the heaters were constructed partly of aluminium and partly of stainless steel. They are 1520 mm in length and 380 mm in diameter, and give a maximum power output of 3000 W. The heater power can be monitored by panel meters coupled to a computer-based data acquisition system. Both the heater and the control system were manufactured with a high degree of redundancy in case of component failure. This report describes the design, construction, testing, installation and necessary tools for heater installation and dismantling operation. (author)

Investigation of Counter-Flow in a Heat Pipe-Thermoelectric Generator (HPTEG)

Science.gov (United States)

Remeli, Muhammad Fairuz; Singh, Baljit; Affandi, Nor Dalila Nor; Ding, Lai Chet; Date, Abhijit; Akbarzadeh, Aliakbar

2017-05-01

This study explores a method of generating electricity while recovering waste heat through the integration of heat pipes and thermoelectric generators (i.e. HPTEG system). The simultaneous waste heat recovery and power generation processes are achieved without the use of any moving parts. The HPTEG system consists of bismuth telluride thermoelectric generators (TEG), which are sandwiched between two finned pipes to achieve a temperature gradient across the TEG for electricity generation. A counter-flow heat exchanger was built using two separate air ducts. The air ducts were thermally coupled using the HPTEG modules. The evaporator section of the heat pipe absorbed the waste heat in a hot air duct. The heat was then transferred across the TEG surfaces. The condenser section of the HPTEG collected the excess heat from the TEG cold side before releasing it to the cold air duct. A 2-kW electrical heater was installed in the hot air duct to simulate the exhaust gas. An air blower was installed at the inlet of each duct to direct the flow of air into the ducts. A theoretical model was developed for predicting the performance of the HPTEG system using the effectiveness-number of transfer units method. The developed model was able to predict the thermal and electrical output of the HPTEG, along with the rate of heat transfer. The results showed that by increasing the cold air velocity, the effectiveness of the heat exchanger was able to be increased from approximately 52% to 58%. As a consequence of the improved heat transfer, maximum power output of 4.3 W was obtained.

Assessment of radioisotope heaters for remote terrestrial applications

International Nuclear Information System (INIS)

Uherka, K.L.

1987-05-01

This paper examines the feasibility of using radioisotope byproducts for special heating applications at remote sites in Alaska and other cold regions. The investigation included assessment of candidate radioisotope materials for heater applications, identification of the most promising cold region applications, evaluation of key technical issues and implementation constraints, and development of conceptual heater designs for candidate applications. Strontium-90 (Sr-90) was selected as the most viable fuel for radioisotopic heaters used in terrestrial applications. Opportunities for the application of radioisotopic heaters were determined through site visits to representative Alaska installations. Candidate heater applications included water storage tanks, sludge digesters, sewage lagoons, water piping systems, well-head pumping stations, emergency shelters, and fuel storage tank deicers. Radioisotopic heaters for water storage tank freeze-up protection and for enhancement of biological waste treatment processes at remote sites were selected as the most promising applications

Distribution and Room Air Mixing Risks to Retrofitted Homes

Energy Technology Data Exchange (ETDEWEB)

Burdick, A. [IBACOS, Inc., Pittsburgh, PA (United States)

2014-12-01

An energy efficiency upgrade reduces a home’s heating and cooling load. If the load reduction is great enough and the heating, ventilation, and air conditioning system warrants replacement, that system is often upgraded with a more efficient, lower capacity system that meets the load of the upgraded house. For a single-story house with floor supply air diffusers, the ducts often are removed and upgraded. For houses with ducts that are embedded in walls, the cost of demolition precludes the replacement of ducts. The challenge with the use of existing ducts is that the reduced airflow creates a decreased throw at the supply registers, and the supply air and room air do not mix well, leading to potential thermal comfort complaints. This project investigates this retrofit scenario. The issues and solutions discussed here are relevant to all climate zones, with emphasis on climates that require cooling. In this project, IBACOS performed load calculations for a two-story 1960s house and characterized duct sizes and layouts based on industry “rules of thumb” (Herk et al. 2014). The team performed duct-sizing calculations for unaltered ducts and post-retrofit airflows and examined airflow velocities and pressure changes with respect to various factors. The team then used a mocked-up duct and register setup to measure the characteristics of isothermal air—to reduce the effects of buoyancy from the observations—passing through the duct and leaving the register.

Humidification dehumidification desalination system using parabolic trough solar air collector

International Nuclear Information System (INIS)

Al-Sulaiman, Fahad A.; Zubair, M. Ifras; Atif, Maimoon; Gandhidasan, Palanichamy; Al-Dini, Salem A.; Antar, Mohamed A.

2015-01-01

This paper deals with a detailed thermodynamic analysis to assess the performance of an HDH system with an integrated parabolic trough solar collector (PTSC). The HDH system considered is an open air, open water, air heated system that uses a PTSC as an air heater. Two different configurations were considered of the HDH system. In the first configuration, the solar air heater was placed before the humidifier whereas in the second configuration the solar air heater was placed between the humidifier and the dehumidifier. The current study revealed that PTSCs are well suited for air heated HDH systems for high radiation location, such as Dhahran, Saudi Arabia. The comparison between the two HDH configurations demonstrates that the gained output ratio (GOR) of the first configuration is, on average, about 1.5 whereas for the second configuration the GOR increases up to an average value of 4.7. The study demonstrates that the HDH configuration with the air heater placed between the humidifier and the dehumidifier has a better performance and a higher productivity. - Highlights: • Thermodynamic analysis of an HDH system driven by a parabolic trough solar collector was conducted. • The first configuration reveals a GOR of 1.5 while the second configuration reveals a GOR of 4.7. • Effective heating of the HDH system was obtained through parabolic trough solar collector

Building America Case Study: Effect of Ducted HPWH on Space Conditioning and Water Heating Energy Use - Central Florida Lab Home, Cocoa, Florida

Energy Technology Data Exchange (ETDEWEB)

C. Colon, E. Martin, and D. Parker

2017-04-01

The purpose of this research is to investigate the impact of ducted heat pump water heaters (HPWH's) on space conditioning and water heating energy use in residential applications. Two identical HPWH's, each of 60 gallon capacity were tested side by side at the Flexible Residential Test facility (FRTF) laboratories of the Florida Solar Energy Center (FSEC) campus in Cocoa, Florida. The water heating experiments were run in each test house from July 2014 until February 2015.

Nocturnal reverse flow in water-in-glass evacuated tube solar water heaters

International Nuclear Information System (INIS)

Tang, Runsheng; Yang, Yuqin

2014-01-01

Highlights: • Performance of water-in-glass evacuated tube solar water heaters (SWH) at night was studied. • Experimental measurements showed that reverse flow occurred in SWHs at night. • Reverse flow in SWHs was very high but the heat loss due to reverse flow was very low. • Reverse flow seemed not sensitive to atmospheric clearness but sensitive to collector tilt-angle. - Abstract: In this work, the thermal performance of water-in-glass evacuated tube solar water heaters (SWH) at nights was experimentally investigated. Measurements at nights showed that the water temperature in solar tubes was always lower than that in the water tank but higher than the ambient air temperature and T exp , the temperature of water inside tubes predicted in the case of the water in tubes being naturally cooled without reverse flow. This signified that the reverse flow in the system occurred at nights, making the water in solar tubes higher than T exp . It is found that the reverse flow rate in the SWH, estimated based on temperature measurements of water in solar tubes, seemed not sensitive to the atmospheric clearness but sensitive to the collector tilt-angle, the larger the tilt-angle of the collector, the higher the reverse flow rate. Experimental results also showed that, the reverse flow in the SWH was much higher as compared to that in a thermosyphonic domestic solar water heater with flat-plate collectors, but the heat loss from collectors to the air due to reverse flow in SWHs was very small and only took about 8–10% of total heat loss of systems

Strategy Guideline: Proper Water Heater Selection

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, M. [Alliance for Residential Building Innovation, Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation, Davis, CA (United States); German, A. [Alliance for Residential Building Innovation, Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation, Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation, Davis, CA (United States)

2015-04-01

This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

Strategy Guideline. Proper Water Heater Selection

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

2015-04-09

This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

Transcystic duct treatment of common bile duct stones

International Nuclear Information System (INIS)

Amberg, J.R.; Chun, G.

1981-01-01

Successful removal of 2 retained common bile duct stones following cholecystostomy is described. With the use of the steerable catheter and the wire basket, one stone was crushed and the second was extracted in retrograde fashion through the cystic duct and gallbladder. (orig.)

Biogas Digester with Simple Solar Heater

Directory of Open Access Journals (Sweden)

Kh S Karimov

2012-10-01

persamaan tenaga seimbang untuk jisim statik cecair yang dipanaskan; parameter penebat haba tangki metana telah dikira. Pencerna biogas terdiri dari tangki metana yang dilengkapkan dengan penyerap pemanas beralik untuk menggunakan tenaga solar bagi memanaskan sluri yang disediakan dari bahan buangan organik yang berbeza (najis, sampah, sisa makanan,etc. Tangki metana telah diisi sehingga 70% isipadu buangan oraganik dari institut GIK, pertamanya adalah sampah dan keduanya adalah najis lembu. Pencerna telah dikaji bagi tempoh tiga bulan (Oktober-Disember, 2009 dan dua bulan (Februari-Mac, 2010. Kejadian radiasi solar terhadap penyerap, suhu sluri dan suhu ambien telah diukur. Didapati suhu penahanan adalah empat minggu dan dua minggu masing-masing dengan menggunakan sampah sahaja dan sampah dengan najis lembu, dan kuantiti biogas dihasilkan adalah masing-masing 0.4 m3 and 8.0 m3. Sebagai tambahan, skema peningkatan biogas untuk peranjakan karbon dioksida, hidrogen sulfida dan wap air dari biogas dan penukaran tenaga biogas kepada tenaga elektrik juga dibincangkan.KEYWORDS:  solar biogas; digester; methane tank; reverse absorber; built-in heater; solar energy

Effect of heater geometry and cavity volume on the sensitivity of a thermal convection-based tilt sensor

Science.gov (United States)

Han, Maeum; Keon Kim, Jae; Kong, Seong Ho; Kang, Shin-Won; Jung, Daewoong

2018-06-01

This paper reports a micro-electro-mechanical-system (MEMS)-based tilt sensor using air medium. Since the working mechanism of the sensor is the thermal convection in a sealed chamber, structural parameters that can affect thermal convection must be considered to optimize the performance of the sensor. This paper presents the experimental results that were conducted by optimizing several parameters such as the heater geometry, input power and cavity volume. We observed that an increase in the heating power and cavity volume can improve the sensitivity, and heater geometry plays important role in performance of the sensor.

A prototype construction of bearing heater system

International Nuclear Information System (INIS)

Firman Silitonga

2007-01-01

A bearing heater system has been successfully constructed using transformer-like method of 1000 VA power, 220 V primary voltage, and 50 Hz electrical frequency. The bearing heater consists of primary coil 230 turns, U type and bar-type iron core with 36 cm 2 , 9 cm 2 ,and 3 cm 2 cross-section, and electrical isolation. The bearing heater is used to enlarge the diameter of the bearing so that it can be easily fixed on an electric motor shaft during replacement because the heating is conducted by treated the bearing as a secondary coil of a transformer. This bearing heater can be used for bearing with 3 and 6 cm of inner diameter and 12 cm of maximum outside diameter. (author)

Performance Analysis of a Modular Small-Diameter Air Distribution System

Energy Technology Data Exchange (ETDEWEB)

Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States); Rudd, Armin [ABT Systems, LLC, Annville, PA (United States)

2016-03-01

This report investigates the feasibility of using a home-run manifold small-diameter duct system to provide space-conditioning air to individual thermal zones in a low-load home. This compact layout allows duct systems to easily be brought within conditioned space via interior partition walls. Centrally locating the air handling unit in the house significantly reduces duct lengths. The plenum box is designed so that each connected duct receives a similar amount of airflow—regardless of its position on the box. Furthermore, within a reasonable set of length restrictions each duct continues to receive similar airflow.

Rare bile duct anomaly: B3 duct draining to gallbladder

Directory of Open Access Journals (Sweden)

Seung Eun Lee

2016-01-01

Full Text Available A 10-year-old girl presented with recurrent right upper abdominal pain and dyspepsia. Magnetic resonance cholangiopancreatography revealed a dilated common channel of intrahepatic bile duct of segment 3 (B3 and segment 4 (B4 drained into the gallbladder directly. The patient underwent laparoscopic cholecystectomy and Roux-en Y hepaticojejunostomy (B3-jejunostomy. Among the anatomical variability of the biliary system, the cholecystohepatic ducts are controversial in existence and incidence. We report a very rare variant of a cholecystohepatic duct in which the B3 duct drained into gallbladder directly and to the best of our knowledge this is the first report.

Solar water heaters in China. A new day dawning

International Nuclear Information System (INIS)

Han, Jingyi; Mol, Arthur P.J.; Lu, Yonglong

2010-01-01

Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in China in recent decades. Manufacturing and marketing developments have been especially strong in provinces such as Zhejiang, Shandong and Jiangsu. This paper takes Zhejiang, a relatively affluent province, as a case study area to assess the performance of solar water heater utilization in China. The study will focus on institutional setting, economic and technological performance, energy performance, and environmental and social impact. Results show that China has greatly increased solar water heater utilization, which has brought China great economic, environmental and social benefits. However, China is confronted with malfeasant market competition, technical flaws in solar water heater products and social conflict concerning solar water heater installation. For further development of the solar water heater, China should clarify the compulsory installation policy and include solar water heaters into the current 'Home Appliances Going to the Countryside' project; most of the widely used vacuum tube products should be replaced by flat plate products, and the technology improvement should focus on anti-freezing and water saving; the resources of solar water heater market should be consolidated and most of the OEM manufacturers should evolve to ODM and OBM enterprises. (author)

Experimental and numerical study on premixed hydrogen/air flame propagation in a horizontal rectangular closed duct

Energy Technology Data Exchange (ETDEWEB)

Xiao, Huahua; Wang, Qingsong; He, Xuechao; Sun, Jinhua; Yao, Liyin [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026 (China)

2010-02-15

Hydrogen is a promising energy in the future, and it is desirable to characterize the combustion behavior of its blends with air. The premixed hydrogen/air flame microstructure and propagation in a horizontal rectangular closed duct were recorded using high-speed video and Schlieren device. Numerical simulation was also performed on Fluent CFD code to compare with the experimental result. A tulip flame is formed during the flame propagating, and then the tulip flame formation mechanism was proposed based on the analysis. The induced reverse flow and vortex motion were observed both in experiment and simulation. The interactions among the flame, reverse flow and vortices in the burned gas change the flame shape and ultimately it develops into a tulip flame. During the formation of the tulip flame, the tulip cusp slows down and stops moving after its slightly forward moving, and then, it starts to move backward and keeps on a longer time, after that, it moves forward again. The structure of the tulip flame is becoming less stable with its length decreasing in flame propagation direction. The flame thickness increases gradually which is due to turbulence combustion. (author)

Feedwater heater

International Nuclear Information System (INIS)

Murata, Shigeto; Minato, Akihiko; Yokomizo, Osamu; Masuhara, Yasuhiro.

1991-01-01

The present invention concerns a feedwater heater for a BWR type reactor. A cylinder is fit into the lower portion of a drain inlet pipe, to which drain water inflows from a turbine, and a disk is disposed to the lower end of the cylinder vertically to the axis of the cylinder, to constitute a drain water dispersing mechanism. Drain water inflown from the drain inlet pipe is fallen in the cylinder and collides against the disk. The collided drain water is splashed horizontally by its kinetic energy to reach the heat transfer pipe and conducts heat exchange. In this case, the drain water is converted into fine droplets by the collision against the disk and scattered in a wide range in the heater. As a result, sensible heat in the drain water can be transferred to feedwater effectively. Then, even the heat energy of the drain water can be utilized effectively for heat exchange, to improve the heat exchange efficiency. (I.N.)

Curved-Duct

Directory of Open Access Journals (Sweden)

Je Hyun Baekt

2000-01-01

Full Text Available A numerical study is conducted on the fully-developed laminar flow of an incompressible viscous fluid in a square duct rotating about a perpendicular axis to the axial direction of the duct. At the straight duct, the rotation produces vortices due to the Coriolis force. Generally two vortex cells are formed and the axial velocity distribution is distorted by the effect of this Coriolis force. When a convective force is weak, two counter-rotating vortices are shown with a quasi-parabolic axial velocity profile for weak rotation rates. As the rotation rate increases, the axial velocity on the vertical centreline of the duct begins to flatten and the location of vorticity center is moved near to wall by the effect of the Coriolis force. When the convective inertia force is strong, a double-vortex secondary flow appears in the transverse planes of the duct for weak rotation rates but as the speed of rotation increases the secondary flow is shown to split into an asymmetric configuration of four counter-rotating vortices. If the rotation rates are increased further, the secondary flow restabilizes to a slightly asymmetric double-vortex configuration. Also, a numerical study is conducted on the laminar flow of an incompressible viscous fluid in a 90°-bend square duct that rotates about axis parallel to the axial direction of the inlet. At a 90°-bend square duct, the feature of flow by the effect of a Coriolis force and a centrifugal force, namely a secondary flow by the centrifugal force in the curved region and the Coriolis force in the downstream region, is shown since the centrifugal force in curved region and the Coriolis force in downstream region are dominant respectively.

Architecture for Absorption Based Heaters

Science.gov (United States)

Moghaddam, Saeed; Chugh, Devesh

2018-04-24

An absorption based heater is constructed on a fluid barrier heat exchanging plate such that it requires little space in a structure. The absorption based heater has a desorber, heat exchanger, and absorber sequentially placed on the fluid barrier heat exchanging plate. The vapor exchange faces of the desorber and the absorber are covered by a vapor permeable membrane that is permeable to a refrigerant vapor but impermeable to an absorbent. A process fluid flows on the side of the fluid barrier heat exchanging plate opposite the vapor exchange face through the absorber and subsequently through the heat exchanger. The absorption based heater can include a second plate with a condenser situated parallel to the fluid barrier heat exchanging plate and opposing the desorber for condensation of the refrigerant for additional heating of the process fluid.

Bile Duct Cancer (Cholangiocarcinoma)

Science.gov (United States)

... Home > Types of Cancer > Bile Duct Cancer (Cholangiocarcinoma) Bile Duct Cancer (Cholangiocarcinoma) This is Cancer.Net’s Guide to Bile Duct Cancer (Cholangiocarcinoma). Use the menu below to ...

Low-frequency noise reduction of fans using the acoustically treated duct; Kyuon duct ni yoru fan soon no teishuhaiki teigen

Energy Technology Data Exchange (ETDEWEB)

Kaneko, K; Fujii, S [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering; Shirasaya, H [Kawasaki Heavy Industries, Ltd., Tokyo (Japan)

1994-12-25

Reducing noise in a low frequency region of 1 kHz or less has become an important problem as a result of emergence of an ultra-high bypass engine in aircraft engines. Therefore, an attempt was made of experimenting and analyzing noise absorption characteristics in low-frequency noises. In the experiment, a low-frequency flow with an air volume of about 3 m{sup 3}/minute was made at a stable operating point of a fan device consisting of moving blades and static blades, with a sound absorbing duct disposed in the forward section. The duct is a 500-mm long steel box with an oblong cross section, in which the top and the bottom parts can move vertically, and a variable air layer was formed between a sound absorbing material (a sheet material made of microfine spherical resin powders solidified to a thickness of 6 mm) and a rigid wall made of iron plate. Noise waves and sound absorption amount were measured on different air layer thicknesses, and analyzed theoretically. As a result, such findings were obtained as: the sound absorption amount is affected by the main stream direction mode of sound pressures in cavity; valleys are formed where the sound absorption amount decreases remarkably in a specific cycle; and peaks are built where the sound absorption amount increases in other regions. 7 refs., 12 figs.

Energy discharge heater power supply

International Nuclear Information System (INIS)

Jaskierny, W.

1992-11-01

The heater power supply is intended to supply capacitively stored,energy to embedded heater strips in cryo magnets. The amount of energy can be controlled by setting different charge different capacitor values. Two chassis' can be operated in series or interlocks are provided. The charge voltage, number of capacitors pulse can be monitored. There and dual channel has two discharge supplies in one chassis. This report reviews the characteristics of this power supply further

Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

Energy Technology Data Exchange (ETDEWEB)

Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

2017-03-01

High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

Energy Technology Data Exchange (ETDEWEB)

Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

2017-03-28

High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

MATHEMATICAL AND INFORMATION SUPPORT FOR CALCULATION AND DESIGN OF TUBE GAS HEATERS LOCATED IN STRUCTURES

Directory of Open Access Journals (Sweden)

CHORNOMORETS H. Y.

2016-02-01

Full Text Available Raising of problem. For the design and construction of tube gas heaters in building structures to need solve the problems of analysis and synthesis of such heating system. The mathematical model of this system is consists of: mathematical model of the tube gas heater, mathematical model of heat distribution in the building structure and corresponding boundary conditions. To solve the tasks of analysis and synthesis must be appropriate mathematical and information support. Purpose. The purpose of this paper is to describe the developed mathematical and information support that solve the problems of analysis and synthesis of heating systems with gas tube heaters, located in building constructions.Conclusion. Mathematical support includes the development of algorithms and software for the numerical solution of problems analysis and synthesis heating system. Information support includes all the necessary parameters characterizing the thermal properties of materials which used in the heating system, and the parameters characterizing the heat exchange between the coolant and components of the heating system. It was developed algorithms for solving problems of analysis and synthesis heating system with tube gas heater located in structures to use evolutionary search algorithm and software. It was made experimental study and was obtained results allow to calculate the heat transfer from the gas-air mixture to the boundary surface of the building structure. This results and computation will provide full information support for solving problems of analysis and synthesis of the heating system. Was developed mathematical and software support, which allows to solve the problems of analysis and synthesis heating systems with gas tube heaters, located in building structures. Tube gas heaters located in the building structures allows with small capital expenditures to provide space heating. Is necessary to solve the problems of analysis (calculation and

Computational Fluid Dynamics Model for Solar Thermal Storage Tanks with Helical Jacket Heater and Upper Spiral Coil Heater

Energy Technology Data Exchange (ETDEWEB)

Baek, Seung Man [Seoul Nat' l Univ., Seoul (Korea, Republic of); Zhong, Yiming; Nam, Jin Hyun [Daegu Univ., Daegu (Korea, Republic of); Chung, Jae Dong [Sejong Univ., Seoul (Korea, Republic of); Hong, Hiki [Kyung Hee Univ., Seoul (Korea, Republic of)

2013-04-15

In a solar domestic hot water (Shadow) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (Test) as hot water. In this study, a computational fluid dynamics (CAD) model was developed to predict the solar thermal energy storage in a hybrid type Test equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a Test, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the Test. The developed model was validated by the good agreement between the CAD results and the experimental results performed with the hybrid-type Test in Shadow settings.

Computational Fluid Dynamics Model for Solar Thermal Storage Tanks with Helical Jacket Heater and Upper Spiral Coil Heater

International Nuclear Information System (INIS)

Baek, Seung Man; Zhong, Yiming; Nam, Jin Hyun; Chung, Jae Dong; Hong, Hiki

2013-01-01

In a solar domestic hot water (Shadow) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (Test) as hot water. In this study, a computational fluid dynamics (CAD) model was developed to predict the solar thermal energy storage in a hybrid type Test equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a Test, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the Test. The developed model was validated by the good agreement between the CAD results and the experimental results performed with the hybrid-type Test in Shadow settings

Developing flow in S-shaped ducts. 2: Circular cross-section duct

Science.gov (United States)

Taylor, A. M. K. P.; Whitelaw, J. H.; Yianneskis, M.

1984-01-01

Laser-Doppler velocimetry measured the laminar and turbulent streamwise flow in a S-duct. The wall pressure distribution and one component of cross-stream velocity were also obtained for the turbulent flow case. Boundary layers near the duct inlet were about 25 percent of the hydraulic diameter in the laminar flow and varied around the periphery of the pipe between 10 percent and 20 percent in turbulent flow. Pressure-driven secondary flows develop in the first half of the S-duct and are attenuated and reversed in the second half. For both Reynolds numbers there is a region near the outer wall of the second half of the duct where the sign of the radial vorticity results in an enforcement of the secondary flow which was established in the first half of the S-duct. The core flow migrates, for both Reynolds numbers, to the outside wall of the first half and lies towards the inside wall of the second half of the S-duct at the outlet. The thinner inlet boundary layers in the turbulent flow give rise to weaker secondary motion.

Flow Simulation of Modified Duct System Wind Turbines Installed on Vehicle

Science.gov (United States)

Rosly, N.; Mohd, S.; Zulkafli, M. F.; Ghafir, M. F. Abdul; Shamsudin, S. S.; Muhammad, W. N. A. Wan

2017-10-01

This study investigates the characteristics of airflow with a flow guide installed and output power generated by wind turbine system being installed on a pickup truck. The wind turbine models were modelled by using SolidWorks 2015 software. In order to investigate the characteristic of air flow inside the wind turbine system, a computer simulation (by using ANSYS Fluent software) is used. There were few models being designed and simulated, one without the rotor installed and another two with rotor installed in the wind turbine system. Three velocities being used for the simulation which are 16.7 m/s (60 km/h), 25 m/s (90 km/h) and 33.33 m/s (120 km/h). The study proved that the flow guide did give an impact to the output power produced by the wind turbine system. The predicted result from this study is the velocity of the air inside the ducting system of the present model is better that reference model. Besides, the flow guide implemented in the ducting system gives a big impact on the characteristics of the air flow.

Process and device for replacing heater in PWR pressurizer

International Nuclear Information System (INIS)

Gente, D.; Giron, M.

1990-01-01

To assure the tight fixation of replacing heater on a pressurizer penetration sleeve, a gas metal-arc welding single pass is executed. A tubular shaft is fixed over end of heater projecting from penetration sleeve. Over shaft is fixed tubular support for the torch which can rotate about axis of support axis heater. Welding torch and welding wire feeder roll are rotated in synchronisation by appropriate motors. Weld is made in single pass round periphery of heater and penetration sleeve [fr

Heater improves cold-temperature capacity of silver-cadmium batteries

Science.gov (United States)

Webster, W. H., Jr.; Jackson, T. P.

1975-01-01

Eight heaters are included in 14-cell package to provide 14-Vdc. Each heater is 11-ohm self-adhesive strip placed across broad face of each pair of cells. They are installed before cells are wired. Heaters are in series and are connected through pair of redundant thermostats.

Multi-step heater deployment in a subsurface formation

Science.gov (United States)

Mason, Stanley Leroy [Allen, TX

2012-04-03

A method for installing a horizontal or inclined subsurface heater includes placing a heating section of a heater in a horizontal or inclined section of a wellbore with an installation tool. The tool is uncoupled from the heating section. A lead in section is mechanically and electrically coupled to the heating section of the heater. The lead-in section is located in an angled or vertical section of the wellbore.

Experimental test of a novel multi-surface trough solar concentrator for air heating

International Nuclear Information System (INIS)

Zheng Hongfei; Tao Tao; Ma Ming; Kang Huifang; Su Yuehong

2012-01-01

Highlights: ► We made a prototype novel multi-surface trough solar concentrator for air heating. ► Circular and rectangular types of receiver were chosen for air heating in the test. ► The changes of instantaneous system efficiency with different air flow were obtained. ► The system has the advantage of high collection temperature, which can be over 140 °C. ► The average efficiency can exceed 45% at the outlet temperature of above 60 °C. - Abstract: This study presents the experimental test of a novel multi-surface trough solar concentrator for air heating. Three receivers of different air flow channels are individually combined with the solar concentrator. The air outlet temperature and solar irradiance were recorded for different air flow rates under the real weather condition and used to determine the collection efficiency and time constant of the air heater system. The characteristics of the solar air heater with different airflow channels are compared, and the variation of the daily efficiency with the normalized temperature change is also presented. The testing results indicates that the highest temperature of the air heater with a circular glass receiver can be over 140 °C. When the collection temperature is around 60 °C, the collection efficiency can be over 45%. For the rectangular receivers, the system also has a considerable daily efficiency at a larger air flow rate. The air heater based on the novel trough solar concentrator would be suitable for space heating and drying applications.

Measure Guideline: Heat Pump Water Heaters in New and Existing Homes

Energy Technology Data Exchange (ETDEWEB)

Shapiro, C.; Puttagunta, S.; Owens, D.

2012-02-01

This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Heat pump water heaters (HPWHs) promise to significantly reduce energy consumption for domestic hot water (DHW) over standard electric resistance water heaters (ERWHs). While ERWHs perform with energy factors (EFs) around 0.9, new HPWHs boast EFs upwards of 2.0. High energy factors in HPWHs are achieved by combining a vapor compression system, which extracts heat from the surrounding air at high efficiencies, with electric resistance element(s), which are better suited to meet large hot water demands. Swapping ERWHs with HPWHs could result in roughly 50% reduction in water heating energy consumption for 35.6% of all U.S. households. This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. While HPWHs promise to significantly reduce energy use for DHW, proper installation, selection, and maintenance of HPWHs is required to ensure high operating efficiency and reliability. This document is intended to explore the issues surrounding HPWHs to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Section 1 of this guideline provides a brief description of HPWHs and their operation. Section 2 highlights the cost and energy savings of HPWHs as well as the variables that affect HPWH performance, reliability, and efficiency. Section 3 gives guidelines for proper installation and maintenance of HPWHs, selection criteria for locating HPWHs, and highlights of important differences between ERWH and HPWH installations. Throughout this document, CARB has included results from the evaluation of 14 heat pump water heaters (including three recently released HPWH

Heater experiments in the Climax Stock, Nevada Test Site

International Nuclear Information System (INIS)

Ramspott, L.; Ballou, L.

1977-01-01

The Climax Stock is a composite granitic intrusive at the Nevada Test Site, with an existing shaft and an open drift about 1400 ft. below the surface. In September 1977, the Lawrence Livermore Laboratory plans to operate three in-situ heater experiments in this area. The first experiment consists of a single heater surrounded by thermocouples at distances of from 1/10 to 5 meters. The close spacing will scale down the time required for useful thermal measurements. The heater, which is 3 meters long and capable of about 3 kW, will be energized for a month, turned off for a month, and the cycle repeated. The rock surface temperature in the heater hole is not expected to exceed 500 to 600 0 C, and the temperature beyond 0.1 m into the rock is not expected to exceed 400 0 C. Measurements will be taken during all four months. These measurements will be compared with numerical simulations to determine the thermal properties of the medium. The second experiment, also involving only a single heater, will be more completely instrumented to include the measurement of permeability, rock displacement, stress/strain, and possibly acoustic emission measurements. The scale of the experiment will be larger, and the heater will be energized continuously for about 4 months. The third test in the series is envisioned to be a scale-up of the second, except that multiple heaters will be used. These heaters will be energized for about a year. They will be arranged around a pillar structure left in the room to obtain information on mine stability in the presence of multiple heaters

ERROR REDUCTION IN DUCT LEAKAGE TESTING THROUGH DATA CROSS-CHECKS

Energy Technology Data Exchange (ETDEWEB)

ANDREWS, J.W.

1998-12-31

One way to reduce uncertainty in scientific measurement is to devise a protocol in which more quantities are measured than are absolutely required, so that the result is over constrained. This report develops a method for so combining data from two different tests for air leakage in residential duct systems. An algorithm, which depends on the uncertainty estimates for the measured quantities, optimizes the use of the excess data. In many cases it can significantly reduce the error bar on at least one of the two measured duct leakage rates (supply or return), and it provides a rational method of reconciling any conflicting results from the two leakage tests.

Highly flexible transparent thin film heaters based on silver nanowires and aluminum zinc oxides

Energy Technology Data Exchange (ETDEWEB)

Cheong, Hahn-Gil; Kim, Jin-Hoon; Song, Jun-Hyuk; Jeong, Unyong; Park, Jin-Woo, E-mail: jwpark09@yonsei.ac.kr

2015-08-31

In this work, we developed highly flexible transparent film heaters (f-TFHs) composed of Ag nanowire networks (AgNWs) and aluminum zinc oxide (AZO). Uniform AgNWs were roll-to-roll coated on polyethylene terephthalate (PET) substrates using the Mayer rod method, and AZO was sputter-deposited atop the AgNWs at room temperature. The sheet resistance (R{sub s}) and transparency (T{sub opt}) of the AZO-coated AgNWs changed only slightly compared with the uncoated AgNWs. AZO is thermally less conductive than the heat pipes, but increases the thermal efficiency of the heaters blocking the heat convection through the air. Based on Joule heating, a higher average film temperature (T{sub ave}) is attained at a fixed electric potential drop between electrodes (ϕ) as the R{sub s} of the film decreases. Our experimental results revealed that T{sub ave} of the hybrid f-TFH is higher than AgNWs when the ratio of the area coverage of AgNWs to AZO is over a certain value. When a ϕ as low as 3 V/cm was applied to 5 cm × 5 cm f-TFHs, the maximum temperature of the hybrid film was over 100 °C, which is greater than that of AgNWs by more than 30 °C. Furthermore, uniform heating throughout the surfaces is achieved in the hybrid films while heating begins in small areas where densities of the nanowires (NWs) are the highest in the bare network. The non-uniform heating decreases the lifetime of f-TFHs by forming hot spots. Cyclic bending test results indicated that the hybrid films were as flexible as the AgNWs, and the R{sub s} of the hybrid films changes only slightly until 5000 cycles. Combined with the high-throughput coating technology presented here, the hybrid films will provide a robust and scalable strategy for large-area f-TFHs with highly enhanced performance. - Highlights: • We developed highly efficient flexible thin film heaters based on Ag nanowires and AZO composites. • In the composite, AZO plays an important role as an insulation blanket to block heat loss to

The effects of air leaks on solar air heating systems

Science.gov (United States)

Elkin, R.; Cash, M.

1979-01-01

This paper presents the results of an investigation to determine the effects of leakages in collector and duct work on the system performance of a typical single-family residence solar air heating system. Positive (leakage out) and negative (leakage in) pressure systems were examined. Collector and duct leakage rates were varied from 10 to 30 percent of the system flow rate. Within the range of leakage rates investigated, solar contribution to heated space and domestic hot water loads was found to be reduced up to 30 percent from the no-leak system contribution with duct leakage equally divided between supply and return duct; with supply duct leakage greater than return leakage a reduction of up to 35 percent was noted. The negative pressure system exhibited a reduction in solar contribution somewhat larger than the positive pressure system for the same leakage rates.

A mixed air/air and air/water heat pump system ensures the air-conditioning of a cinema; Un systeme mixte PAC air/air et air/eau climatise un cinema

Energy Technology Data Exchange (ETDEWEB)

Anon.

2001-03-01

This article presents the air conditioning system of a new cinema complex of Boulogne (92, France) which comprises a double-flux air processing plant and two heat pumps. Each heat pump has two independent refrigerating loops: one with a air condenser and the other with a water condenser. This system allows to limit the power of the loop and to reduce the size of the cooling tower and of the vertical ducts. This article describes the technical characteristics of the installation: thermodynamic units, smoke clearing, temperature control, air renewing. (J.S.)

A New Type of Complex System of Solar Energy Air Source Heat Pump Water Heater%一种新型的太阳能——空气源复合热泵热水器系统

Institute of Scientific and Technical Information of China (English)

王军军

2011-01-01

基于太阳能热利用技术、空气源热泵热水器理论，介绍了一种将太阳能与空气源相结合的双热源热泵热水器系统。该系统可充分利用太阳能加热生活用热水，辅以空气源热泵来满足太阳辐射照度不足时的用热水需求，同时用太阳能辅助加热来解决低温环境下空气源热泵运行工况恶劣的问题。系统充分利用了低品位的太阳能，保证稳定性，又可提高夏季阴雨天气、过渡季节及冬季太阳能热水器的热水温度，对于节约能源和环境保护具有重要意义。%Based on the technology of solar thermal and the theory of air-source heat pump water heater, a combined water heater system about solar and air source heat pump was introduced. The system Could make full use of solar energy to heat domestic hot water, combined with air-source heat pump to meet the shortage of solar irradiance when the hot water demand, and the auxiliary heating with solar energy to solve the problems of air source heat pump operating conditions in low temperature. The system took full use of the low-grade solar energy, and stability could be assured. And it could improve the temperature of the water in solar water heaters in rainy summers, transition seasons and winters. The system had significance for energy conservation and environmental protection.

Research and development of a high efficiency gas-fired water heater. Volume 2. Task reports

Energy Technology Data Exchange (ETDEWEB)

Vasilakis, A.D.; Pearson, J.F.; Gerstmann, J.

1980-01-01

Design and development of a cost-effective high efficiency gas-fired water heater to attain a service efficiency of 70% (including the effect of exfiltration) and a service efficiency of 78% (excluding exfiltration) for a 75 GPD draw at a 90/sup 0/F temperature rise, with a stored water to conditioned air temperature difference of 80/sup 0/F, are described in detail. Based on concept evaluation, a non-powered natural draft water heater was chosen as the most cost-effective design to develop. The projected installed cost is $374 compared to $200 for a conventional unit. When the project water heater is compared to a conventional unit, it has a payback of 3.7 years and life cycle savings of $350 to the consumer. A prototype water heater was designed, constructed, and tested. When operated with sealed combustion, the unit has a service efficiency of 66.4% (including the effect of exfiltration) below a burner input of 32,000 Btu/h. In the open combustion configuration, the unit operated at a measured efficiency of 66.4% Btu/h (excluding exfiltration). This compares with a service efficiency of 51.3% for a conventional water heater and 61% for a conventional high efficiency unit capable of meeting ASHRAE 90-75. Operational tests showed the unit performed well with no evidence of stacking or hot spots. It met or exceeded all capacity or usage tests specified in the program test plan and met all emission goals. Future work will concentrate on designing, building, and testing pre-production units. It is anticipated that both sealed combustion and open draft models will be pursued.

Solar-powered hot-air system

Science.gov (United States)

1979-01-01

Solar-powered air heater supplies part or all of space heating requirements of residential or commercial buildings and is interfaced with air to water heat exchanger to heat domestic hot water. System has potential application in drying agricultural products such as cotton, lumber, corn, grains, and peanuts.

Distribution and Room Air Mixing Risks to Retrofitted Homes

Energy Technology Data Exchange (ETDEWEB)

Burdick, A. [IBACOS, Inc., Pittsburgh, PA (United States)

2014-12-01

Energy efficiency upgrades reduce heating and cooling loads on a house. With enough load reduction and if the HVAC system warrants replacement, the HVAC system is often upgraded with a more efficient, lower capacity system that meets the loads of the upgraded house. For a single-story house with ceiling supply air diffusers, ducts are often removed and upgraded. For houses with ducts that are embedded in walls, the cost of demolition precludes the replacement of ducts. The challenge with the use of existing ducts is that the reduced airflow creates a decreased throw at the supply registers, and the supply air and room air do not mix well, leading to potential thermal comfort complaints. This project investigates this retrofit scenario. The issues and solutions discussed here are relevant to all climate zones, with emphasis on climates that require cooling.

Analysis of polymer foil heaters as infrared radiation sources

International Nuclear Information System (INIS)

Witek, Krzysztof; Piotrowski, Tadeusz; Skwarek, Agata

2012-01-01

Infrared radiation as a heat source is used in many fields. In particular, the positive effect of far-infrared radiation on living organisms has been observed. This paper presents two technological solutions for infrared heater production using polymer-silver and polymer-carbon pastes screenprinted on foil substrates. The purpose of this work was the identification of polymer layers as a specific frequency range IR radiation sources. The characterization of the heaters was determined mainly by measurement of the surface temperature distribution using a thermovision camera and the spectral characteristics were determined using a special measuring system. Basic parameters obtained for both, polymer silver and polymer carbon heaters were similar and were as follows: power rating of 10–12 W/dm 2 , continuous working surface temperature of 80–90 °C, temperature coefficient of resistance (TCR) about +900 ppm/K for polymer-carbon heater and about +2000 ppm/K for polymer-silver, maximum radiation intensity in the wavelength range of 6–14 μm with top intensity at 8.5 μm and heating time about 20 min. For comparison purposes, commercial panel heater was tested. The results show that the characteristics of infrared polymer heaters are similar to the characteristics of the commercial heater, so they can be taken into consideration as the alternative infrared radiation sources.

Effects of heater location and heater size on the natural convection heat transfer in a square cavity using finite element method

Energy Technology Data Exchange (ETDEWEB)

Ngo, Ich Long; Byon, Chan [Yeungnam University, Gyeongsan (Korea, Republic of)

2015-07-15

Finite element method was used to investigate the effects of heater location and heater size on the natural convection heat transfer in a 2D square cavity heated partially or fully from below and cooled from above. Rayleigh number (5 X 10{sup 2} ≤ Ra ≤ 5X10{sup 5}), heater size (0.1 ≤ D/L ≤ 1.0), and heater location (0.1 ≤ x{sub h}/L ≤ 0.5) were considered. Numerical results indicated that the average Nusselt number (Nu{sub m}) increases as the heater size decreases. In addition, when x{sub h}/L is less than 0.4, Nu{sub m} increases as x{sub h}/L increases, and Num decreases again for a larger value of x{sub h}/L. However, this trend changes when Ra is less than 10{sup 4}, suggesting that Nu{sub m} attains its maximum value at the region close to the bottom surface center. This study aims to gain insight into the behaviors of natural convection in order to potentially improve internal natural convection heat transfer.

Householders' use of storage heaters

Energy Technology Data Exchange (ETDEWEB)

Crawshaw, C M; Williams, D I; Steele, L M

1986-11-01

An investigation into the understanding and use of storage heater controls was carried out. The general level of satisfaction with storage heating was high (90%) and most people had a reasonable idea of how the system works, what the controls do and of the tariff costs. However, the study did find substantial areas of ignorance; 37% could not say what controls their heater had and 15% did not know what tariff they were on. This lack of knowledge may prevent users getting the best performance from their heating system, resulting in discomfort and large bills.

Propagation of sound waves in ducts

DEFF Research Database (Denmark)

Jacobsen, Finn

2000-01-01

Plane wave propagation in ducts with rigid walls, radiation from ducts, classical four-pole theory for composite duct systems, and three-dimentional waves in wave guides of various cross-sectional shape are described.......Plane wave propagation in ducts with rigid walls, radiation from ducts, classical four-pole theory for composite duct systems, and three-dimentional waves in wave guides of various cross-sectional shape are described....

Thermohydraulic analysis of smooth and finned annular ducts

International Nuclear Information System (INIS)

Braga, C.V.M.

1987-01-01

The present work is concerned with the turbulent heat transfer and pressure drop in smooth and finned annular ducts overage heat transfer coefficients have been obtained by means of the heat exchanger theory. In addition, friction factors have also been determined. The experiments were performed by utilizing four double-pipe heat exchangers. The flowing fluids, in the heat exchangers, were air and water. The average heat transfer coefficients, for air flowing in the annular section, were determined by measuring the overall heat transfer coefficients of the heat exchangers. In order to attain fully developed conditions, the heat exchangers had a starting length of 30 hydraulic diameters. The thermal boundary conditions consisted of uniform temperature on the inner surface, the outer surface being insulated. The heat transfer coefficients and friction factors are presented in dimensionaless forms, as functions of the Reynolds number of the flow. The results for the smooth and finned annular ducts were compared. The purpose of such comparison was to study the influence of the fins on the pressure drop and heat transfer rate. In the case of the finned nular ducts, it is shown that the fin efficiency has some fluence on the heat transfer rates. The, a two-dimensional at transfer analysis was performed in order to obtain the n efficiency and the annular region efficiency. It is also shown that the overall thermal performance of finned surfaces epends mainly on the Nusselt number and on the region eficiency. These parameters are presented as functions of the Reynolds number of the flow and the geometry of the problem. (author) [pt

Duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma.

Science.gov (United States)

Wu, Wen-Guang; Gu, Jun; Dong, Ping; Lu, Jian-Hua; Li, Mao-Lan; Wu, Xiang-Song; Yang, Jia-Hua; Zhang, Lin; Ding, Qi-Chen; Weng, Hao; Ding, Qian; Liu, Ying-Bin

2013-04-21

At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a single-layer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow-up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.

A visual study of forced convection boiling. Part I: Results for a flat vertical heater

International Nuclear Information System (INIS)

Kirby, G.J.; Staniforth, R.; Kinneir, J.H.

1965-03-01

This report presents the first results of a visual study of the hydrodynamics of boiling in channels and of burnout. It was found that the bubbles formed did not diffuse into the main stream at high heat fluxes, but remained close to the heater. Consequently severe coalescence took place, resulting in the formation of large regularly shaped bubbles. An analysis of the forces acting on these bubbles is given; this accounts qualitatively for the observed behaviour. The above bubble formations result from the addition of heat at a wall so that clearly isothermal models, such as those using air-water mixtures, cannot give a true representation of the flow pattern. Attempts to view the heater surface at burnout were frustrated by poor visibility through the boiling mixture. (author)

Infrared transparent graphene heater for silicon photonic integrated circuits.

Science.gov (United States)

Schall, Daniel; Mohsin, Muhammad; Sagade, Abhay A; Otto, Martin; Chmielak, Bartos; Suckow, Stephan; Giesecke, Anna Lena; Neumaier, Daniel; Kurz, Heinrich

2016-04-18

Thermo-optical tuning of the refractive index is one of the pivotal operations performed in integrated silicon photonic circuits for thermal stabilization, compensation of fabrication tolerances, and implementation of photonic operations. Currently, heaters based on metal wires provide the temperature control in the silicon waveguide. The strong interaction of metal and light, however, necessitates a certain gap between the heater and the photonic structure to avoid significant transmission loss. Here we present a graphene heater that overcomes this constraint and enables an energy efficient tuning of the refractive index. We achieve a tuning power as low as 22 mW per free spectral range and fast response time of 3 µs, outperforming metal based waveguide heaters. Simulations support the experimental results and suggest that for graphene heaters the spacing to the silicon can be further reduced yielding the best possible energy efficiency and operation speed.

Research and development of a heat-pump water heater. Volume 2. R and D task reports

Energy Technology Data Exchange (ETDEWEB)

Dunning, R.L.; Amthor, F.R.; Doyle, E.J.

1978-08-01

The heat pump water heater is a device that works much like a window air conditioner except that heat from the home is pumped into a water tank rather than to the outdoors. The objective established for the device is to operate with a Coefficient of Performance (COP) of 3 or, an input of one unit of electric energy would create three units of heat energy in the form of hot water. With such a COP, the device would use only one-third the energy and at one-third the cost of a standard resistance water heater. This Volume 2 contains the final reports of the three major tasks performed in Phase I. In Task 2, a market study identifies the future market and selects an initial target market and channel of distribution, all based on an analysis of the parameters affecting feasibility of the device and the factors that will affect its market acceptance. In the Task 3 report, the results of a design and test program to arrive at final designs of heat pumps for both new water heaters and for retrofitting existing water heaters are presented. In the Task 4 report, a plan for an extensive field demonstration involving use in actual homes is presented. Volume 1 contains a final summary report of the information in Volume 2.

Reciprocity principle in duct acoustics

Science.gov (United States)

Cho, Y.-C.

1979-01-01

Various reciprocity relations in duct acoustics have been derived on the basis of the spatial reciprocity principle implied in Green's functions for linear waves. The derivation includes the reciprocity relations between mode conversion coefficients for reflection and transmission in nonuniform ducts, and the relation between the radiation of a mode from an arbitrarily terminated duct and the absorption of an externally incident plane wave by the duct. Such relations are well defined as long as the systems remain linear, regardless of acoustic properties of duct nonuniformities which cause the mode conversions.

A theoretical model for flow boiling CHF from short concave heaters

International Nuclear Information System (INIS)

Galloway, J.E.; Mudawar, I.

1995-01-01

Experiments were performed to enable the development of a new theoretical mode for the enhancement in CHF commonly observed with flow boiling on concave heater as compared to straight heaters. High-speed video imaging and photomicrography were employed to capture the trigger mechanism for CHF each type heater. A wavy vapor layer was observed to engulf the heater surface in each case, permitting liquid access to the surface only in regions where depressions (troughs) in the liquid vapor interface made contact with the surface. CHF in each case occurred when the pressure force exerted upon the wavy vapor-liquid inter ace in the contact region could no longer overcome the momentum of the vapor produced in these regional. Shorter interfacial wavelengths with greater curvature were measured on the curve, heater than on the straight heater, promoting a greater pressure force on the wave interface and a corresponding increase in CHF for the curved heater. A theoretics. CHF model is developed from these observations, based upon a new theory for hydrodynamic instability, along a curved interface. CHF data are predicted with good accuracy for both heaters. 23 refs., 9 figs

Thermally driven self-healing using copper nanofiber heater

Science.gov (United States)

Lee, Min Wook; Jo, Hong Seok; Yoon, Sam S.; Yarin, Alexander L.

2017-07-01

Nano-textured transparent heaters made of copper nanofibers (CuNFs) are used to facilitate accelerated self-healing of bromobutyl rubber (BIIR). The heater and BIIR layer are separately deposited on each side of a transparent flexible polyethylene terephthalate (PET) substrate. A pre-notched crack on the BIIR layer was bridged due to heating facilitated by CuNFs. In the corrosion test, a cracked BIIR layer covered a steel substrate. An accelerated self-healing of the crack due to the transparent copper nanofiber heater facilitated an anti-corrosion protective effect of the BIIR layer.

Implementation of heaters on thermally actuated spacecraft mechanisms

Science.gov (United States)

Busch, John D.; Bokaie, Michael D.

1994-01-01

This paper presents general insight into the design and implementation of heaters as used in actuating mechanisms for spacecraft. Problems and considerations that were encountered during development of the Deep Space Probe and Science Experiment (DSPSE) solar array release mechanism are discussed. Obstacles included large expected fluctuations in ambient temperature, variations in voltage supply levels outgassing concerns, heater circuit design, materials selection, and power control options. Successful resolution of these issues helped to establish a methodology which can be applied to many of the heater design challenges found in thermally actuated mechanisms.

Reference values of MRI measurements of the common bile duct and pancreatic duct in children

Energy Technology Data Exchange (ETDEWEB)

Gwal, Kriti; Bedoya, Maria A.; Patel, Neal; Darge, Kassa; Anupindi, Sudha A. [University of Pennsylvania Perelman School of Medicine, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Rambhatla, Siri J. [Beth Israel Medical Center, Department of Pediatrics, Newark, NJ (United States); Sreedharan, Ram R. [University of Pennsylvania, Departments of Gastroenterology, Hepatology and Nutrition, The Children' s Hospital of Philadelphia, Perelman School of Medicine, Philadelphia, PA (United States)

2015-08-15

Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial

Reference values of MRI measurements of the common bile duct and pancreatic duct in children

International Nuclear Information System (INIS)

Gwal, Kriti; Bedoya, Maria A.; Patel, Neal; Darge, Kassa; Anupindi, Sudha A.; Rambhatla, Siri J.; Sreedharan, Ram R.

2015-01-01

Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial

Bile duct stricture

Science.gov (United States)

... duct, the tube that moves bile from the liver to the small intestine. Bile is a substance that helps with digestion. ... causes of this condition include: Cancer of the bile duct, liver or pancreas Damage and scarring due to a ...

Blocked Tear Duct

Science.gov (United States)

... of the nose (lacrimal sac). From there tears travel down a duct (the nasolacrimal duct) draining into your nose. Once in the nose, tears are reabsorbed. A blockage can occur at any point in the tear drainage system, from the puncta ...

Experimental and theoretical investigation of Stirling engine heater: Parametrical optimization

International Nuclear Information System (INIS)

Gheith, R.; Hachem, H.; Aloui, F.; Ben Nasrallah, S.

2015-01-01

Highlights: • A Stirling engine was investigated to optimize its operation and its performance. • The porous medium present the highest amount of heat exchanged in a Stirling engine. • The heater characteristics are determinant points to enhance the thermal exchange in Stirling engine. • All operation parameters influence the heater performances. • Thermal and exergy heater efficiencies are sensible to temperature and pressure. - Abstract: The aim of this work is to optimize γ Stirling engine performances with a special care given to the heater. This latter consists of 20 tubes in order to increase the exchange area between the working gas and the hot source. Different parameters were chosen to evaluate numerically and experimentally the heater. The selected four independent parameters are: heating temperature (300–500 °C), initial filling pressure (3–8 bar), cooling water flow rate (0.2–3 l/min) and frequency (2–7 Hz). The amount of energy exchanged in the heater is significantly influenced by the frequency and heating temperature but it is slightly enhanced with the increase in the cooling water flow rate. The thermal and the exergy efficiencies of the heater are very sensible to the temperature and pressure variations.

Recovery Act: Water Heater ZigBee Open Standard Wireless Controller

Energy Technology Data Exchange (ETDEWEB)

Butler, William P. [Emerson Electric Co., St. Louis, MO (United States); Buescher, Tom [Emerson Electric Co., St. Louis, MO (United States)

2014-04-30

The objective of Emerson's Water Heater ZigBee Open Standard Wireless Controller is to support the DOE's AARA priority for Clean, Secure Energy by designing a water heater control that levels out residential and small business peak electricity demand through thermal energy storage in the water heater tank.

A silicon nanowire heater and thermometer

Science.gov (United States)

Zhao, Xingyan; Dan, Yaping

2017-07-01

In the thermal conductivity measurements of thermoelectric materials, heaters and thermometers made of the same semiconducting materials under test, forming a homogeneous system, will significantly simplify fabrication and integration. In this work, we demonstrate a high-performance heater and thermometer made of single silicon nanowires (SiNWs). The SiNWs are patterned out of a silicon-on-insulator wafer by CMOS-compatible fabrication processes. The electronic properties of the nanowires are characterized by four-probe and low temperature Hall effect measurements. The I-V curves of the nanowires are linear at small voltage bias. The temperature dependence of the nanowire resistance allows the nanowire to be used as a highly sensitive thermometer. At high voltage bias, the I-V curves of the nanowire become nonlinear due to the effect of Joule heating. The temperature of the nanowire heater can be accurately monitored by the nanowire itself as a thermometer.

Study on heat and mass transfer between a greenhouse considered as a solar air heater and a rock packed bed as ambient control system

International Nuclear Information System (INIS)

Ajona Maeztu, J.I.

1990-01-01

A general study on heat transfer in dry packed beds is made, with special emphasis in comparing different transient models and in identifying the required conditions by which the attained results are equivalent. The differences in thermal behaviour on packed beds, when simultaneous heat mass transfer occurs as wet air is used as heat transfer fluid and exchanges heat and water with the solid in the bed, is analyzed. We modelize wet packed beds considering them as one dimension adsorbents beds, with dispersive and non-dispersive models, where adsorption, condensation-evaporation and liquid water downward flow from condensate phenomena are present. Models were solved numerically and experiments with a rock bed with dry and wet air through it, were made to test assumptions and to further understand the behavior of the system, obtaining a pretty good agreement between expected and measured profiles of the temperature evolution within the packed bed. As a possible application of the wet rock bed for storage purposes, a forced ventilation greenhouse was characterized as a wet air solar heater and analyzed the energetic potential of storing the heat that has to be rejected during daytime to control the crop ambient conditions, in a rock bed for later use at night for heating. (author)

Solar project description for Public Service Company of New Mexico (lot 7) single family residence, Rio Rancho, New Mexico

Science.gov (United States)

1981-08-01

A solar space heating/domestic hot water system employing 150 square feet air flat plate collectors and 20,000 pounds of rock for storage is described. The collector, storage, energy to load, and auxiliary heat subsystems and five modes of operation are described. Auxiliary space heating is provided by an electric strip heater in the air ducts. The hot water system consists of an 80 gallon solar preheating tank which supplies a 40 gallon conventional tank. An electric heating element provides auxiliary heating in the preheat tank.

Partial Avulsion of Common Bile Duct and Duodenal Perforation in a Blunt Abdominal Trauma

OpenAIRE

Mirza, Bilal; Ijaz, Lubna; Iqbal, Shahid; Sheikh, Afzal

2010-01-01

Complete or partial avulsion of common bile duct is a very rare injury following blunt abdominal trauma in children. A 7-year old boy presented to ER following blunt abdominal trauma by a moving motorcycle. X ray abdomen revealed free air under diaphragm and CT scan showed pancreatic contusion injury. At operation anterior wall of common bile duct (CBD) along with a 2mm rim of duodenal tissue on either side of anterior wall of CBD were found avulsed from the duodenum. The avulsed portion of C...

Test design requirements: Canister-scale heater test

International Nuclear Information System (INIS)

Schauer, M.I.; Craig, P.A.; Stickney, R.G.

1986-03-01

This document establishes the Test Design Requirements for the design of a canister scale heater test to be performed in the Exploratory Shaft test facility. The purpose of the test is to obtain thermomechanical rock mass response data for use in validation of the numerical models. The canister scale heater test is a full scale simulation of a high-level nuclear waste container in a prototypic emplacement borehole. Electric heaters are used to simulate the heat loads expected in an actual waste container. This document presents an overview of the test including objectives and justification for the test. A description of the test as it is presently envisioned is included. Discussions on Quality Assurance and Safety are also included in the document. 12 refs., 1 fig

Filament heater current modulation for increased filament lifetime

International Nuclear Information System (INIS)

Paul, J.D.; Williams, H.E. III.

1996-01-01

The surface conversion H-minus ion source employs two 60 mil tungsten filaments which are approximately 17 centimeters in length. These filaments are heated to approximately 2,800 degrees centigrade by 95--100 amperes of DC heater current. The arc is struck at a 120 hertz rate, for 800 microseconds and is generally run at 30 amperes peak current. Although sputtering is considered a contributing factor in the demise of the filament, evaporation is of greater concern. If the peak arc current can be maintained with less average heater current, the filament evaporation rate for this arc current will diminish. In the vacuum of an ion source, the authors expect the filaments to retain much of their heat throughout a 1 millisecond (12% duty) loss of heater current. A circuit to eliminate 100 ampere heater currents from filaments during the arc pulse was developed. The magnetic field due to the 100 ampere current tends to hold electrons to the filament, decreasing the arc current. By eliminating this magnetic field, the arc should be more efficient, allowing the filaments to run at a lower average heater current. This should extend the filament lifetime. The circuit development and preliminary filament results are discussed

40 CFR Table 2 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Particulate Matter Emission Limits

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Operating Limits for Boilers and Process Heaters With Particulate Matter Emission Limits 2 Table 2 to Subpart DDDDD of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION...

Experimental study of neutron streaming through steel-walled annular ducts in reactor shields

International Nuclear Information System (INIS)

Toshimas, M.; Nobuo, S.

1983-01-01

For the purpose of providing experimental data to assess neutron streaming calculations, neutron flux measurements were performed along the axes of the steel-walled annular ducts set up in a water shield of the pool-type reactor JRR-4. An annular duct simulated the air gap around the main coolant pipe. Another duct simulated the streaming path around the primary circulating pump of the integrated-type marine reactor. A 90-deg bend annular duct was also studied. In a set of measurements, the distance Z between the core center and the duct axis and the annular gap width delta were taken as parameters, that is, Z = 0, 80, and 160 cm and delta = 2.2, 4.7, and 10.1 cm. The reaction rates and the fluxes measured by the activation method are given in terms of absolute magnitude within an accuracy of + or - 30%. An empirical formula is derived based on those measured data, which describes the axial distribution of the neutron flux in the steel-walled annular duct in reactor shields. It is expressed by a simple function of the axial distance in units of the square root of the line-of-sight area, S /SUB l/ . The accuracy of the formula is examined by taking into account the duct location with respect to the reactor core, the neutron energy, the steel wall thickness, and the media outside of the steel wall. The accuracy of the formula is, in general, <30% in the axial distance between 3√S /SUB l/ and 30√S /SUB l/

Navier-Stokes analysis and experimental data comparison of compressible flow within ducts

Science.gov (United States)

Harloff, G. J.; Reichert, B. A.; Sirbaugh, J. R.; Wellborn, S. R.

1992-01-01

Many aircraft employ ducts with centerline curvature or changing cross-sectional shape to join the engine with inlet and exhaust components. S-ducts convey air to the engine compressor from the intake and often decelerate the flow to achieve an acceptable Mach number at the engine compressor by increasing the cross-sectional area downstream. Circular-to-rectangular transition ducts are used on aircraft with rectangular exhaust nozzles to connect the engine and nozzle. To achieve maximum engine performance, the ducts should minimize flow total pressure loss and total pressure distortion at the duct exit. Changes in the curvature of the duct centerline or the duct cross-sectional shape give rise to streamline curvature which causes cross stream pressure gradients. Secondary flows can be caused by deflection of the transverse vorticity component of the boundary layer. This vortex tilting results in counter-rotating vortices. Additionally, the adverse streamwise pressure gradient caused by increasing cross-sectional area can lead to flow separation. Vortex pairs have been observed in the exit planes of both duct types. These vortices are due to secondary flows induced by pressure gradients resulting from streamline curvature. Regions of low total pressure are produced when the vortices convect boundary layer fluid into the main flow. The purpose of the present study is to predict the measured flow field in a diffusing S-duct and a circular-to-rectangular transition duct with a full Navier-Stokes computer program, PARC3D, and to compare the numerical predictions with new detailed experimental measurements. The work was undertaken to extend previous studies and to provide additional CFD validation data needed to help model flows with strong secondary flow and boundary layer separation. The S-duct computation extends the study of Smith et al, and Harloff et al, which concluded that the computation might be improved by using a finer grid and more advanced turbulence models

Energy efficiency improvement and fuel savings in water heaters using baffles

International Nuclear Information System (INIS)

Moeini Sedeh, Mahmoud; Khodadadi, J.M.

2013-01-01

Highlights: ► Thermal efficiency improved by simple/novel design of baffles inside water reservoir. ► Noticeable steady-state natural gas savings of about 5%. ► Extensive 3-D numerical investigations followed by experimental verifications. ► Baffle designs prototyped in identical water heaters for ANSI/US DOE test protocols. ► Numerical/experimental results verified thermal efficiency improvement and fuel savings. -- Abstract: Thermal efficiency improvement of a water heater was investigated numerically and experimentally in response to presence of a baffle, particularly designed for modifying the flow field within the water reservoir and enhancing heat transfer extracted into the water tank. A residential natural gas-fired water heater was selected for modifying its water tank through introducing a baffle for lowering natural gas consumption by 5% as a target. Based on the geometric features of the selected water heater, three-dimensional models of the water heater subsections were developed. Upon detailed studies of flow and heat transfer in each subsection, various sub-models were integrated to a complete model of the water heater. Thermal performance of the selected water heater was investigated numerically using computational fluid dynamics analysis. Prior to baffle design process and in order to verify the developed model of the water heater, time-dependent numerically-predicted temperatures were compared to the experimentally-measured temperatures under the same conditions at six (6) different locations inside the water tank and good agreement was observed. Upon verifying the numerical model, the fluid flow and heat transfer patterns were characterized for the selected water heater. The overall design of the baffle and its location and orientation were finalized based on the numerical results and a set of parametric studies. Finally, two baffle designs were proposed, with the second design being an optimized version of the first design. The

Solar-Powered Cooler and Heater for an Automobile Interior

Science.gov (United States)

Howard, Richard T.

2006-01-01

The apparatus would include a solar photovoltaic panel mounted on the roof and a panellike assembly mounted in a window opening. The window-mounted assembly would include a stack of thermoelectric devices sandwiched between two heat sinks. A fan would circulate interior air over one heat sink. Another fan would circulate exterior air over the other heat sink. The fans and the thermoelectric devices would be powered by the solar photovoltaic panel. By means of a double-pole, double-throw switch, the panel voltage fed to the thermoelectric stack would be set to the desired polarity: For cooling operation, the chosen polarity would be one in which the thermoelectric devices transport heat from the inside heat sink to the outside one; for heating operation, the opposite polarity would be chosen. Because thermoelectric devices are more efficient in heating than in cooling, this apparatus would be more effective as a heater than as a cooler. However, if the apparatus were to include means to circulate air between the outside and the inside without opening the windows, then its effectiveness as a cooler in a hot, sunny location would be increased.

Feasibility of applying coal-fired boiler technology to process heaters

Energy Technology Data Exchange (ETDEWEB)

O' Sullivan, T F

1978-01-01

The preponderance of coal in US fossil fuel reserves has raised the question of the conversion of hydrocarbon process heaters to coal firing. A review undertaken in 1977 by an API sub-committee concluded that neither existing heaters nor existing heater designs were capable of modification or revision to burn coal, and that new coal-fired design consistent with process requirements would be needed for this purpose. In recognition of this need a cooperative investigation was undertaken by Combustion Engineering and Lummus. The present paper, reporting on this investigation, reviews existing coal-fired boiler equipment and techniques and describes their adaptation to the development of a design concept for a coal-fired process heater. To this end, the design parameters for both steam boilers and fired heaters have been compared and have been incorporated into a workable coal-fired process heater design which includes the following features; a coutant bottom for ash removal, an ash-hopper located under both radiant and convection chambers, a tangent type finned wall construction, a straight through gas flow pattern, a vertical tube convection section, horizontal firing using round burners, and an overall geometry allowing a coil arrangement capable of accommodating varying numbers of parallel serpentine coils. These features are integrated into a conceptual heater design which is detailed in a series of illustrations.

Ducted fuel injection

Energy Technology Data Exchange (ETDEWEB)

Mueller, Charles J.

2018-03-06

Various technologies presented herein relate to enhancing mixing inside a combustion chamber to form one or more locally premixed mixtures comprising fuel and charge-gas with low peak fuel to charge-gas ratios to enable minimal, or no, generation of soot and other undesired emissions during ignition and subsequent combustion of the locally premixed mixtures. To enable sufficient mixing of the fuel and charge-gas, a jet of fuel can be directed to pass through a bore of a duct causing charge-gas to be drawn into the bore creating turbulence to mix the fuel and the drawn charge-gas. The duct can be located proximate to an opening in a tip of a fuel injector. The duct can comprise of one or more holes along its length to enable charge-gas to be drawn into the bore, and further, the duct can cool the fuel and/or charge-gas prior to combustion.

Life cycle assesment for glasswool panels of HVAC ducts. External Verification

Directory of Open Access Journals (Sweden)

S. Herranz García

2018-02-01

Full Text Available This paper presents the current situation of the environmental behavior, throughout its life cycle, of air conditioning ducts made of glass wool panels. Their use is more and more common in the realization of high efficiency installations, frequently replacing sheet metal ducts coated with glass wool blankets, due to the advantages they bring to the installation. The life cycle analysis allows us to quantify the environmental impact of these products. The procedure will be based on the UNE-EN 15804: 2012 + A1 standard, which defines the common framework for harmonizing the structure of Environmental Product Declarations in building materials and gives veracity scientific based on the environmental data provided, when verified by a third part.

Water hammers in direct contact heater systems

International Nuclear Information System (INIS)

Uffer, R.

1983-01-01

This paper discusses the causes and mitigation or prevention of water hammers occurring in direct contact heaters and their attached lines. These water hammers are generally caused by rapid pressure reductions in the heaters or by water lines not flowing full. Proper design and operating measures can prevent or mitigate water hammer occurrence. Water hammers often do not originate at the areas where damage is noted

Temperature limited heater utilizing non-ferromagnetic conductor

Science.gov (United States)

Vinegar,; Harold J. , Harris; Kelvin, Christopher [Houston, TX

2012-07-17

A heater is described. The heater includes a ferromagnetic conductor and an electrical conductor electrically coupled to the ferromagnetic conductor. The ferromagnetic conductor is positioned relative to the electrical conductor such that an electromagnetic field produced by time-varying current flow in the ferromagnetic conductor confines a majority of the flow of the electrical current to the electrical conductor at temperatures below or near a selected temperature.

Thermal neutrons streaming in straight duct

International Nuclear Information System (INIS)

Jehouani, A.; Boulkheir, M.; Ichaoui, R.

2000-01-01

The neutron streaming in duct is due to two phenomena: a) direct propagation and b) reflection on duct wall. We have used the Monte Carlo method to evaluate the ratio of the reflected neutrons flux by the duct wall to the total flux at the exit of the duct for iron and aluminium. Ten neutrons energy groups are considered between 10 -5 eV and 10 eV. A Fortran program is developed to evaluate the neutron double differential albedo. It is shown that the two following approximations are largely justified: i) Three collisions in the duct wall are sufficient to attain the asymptotic limit of the multiscattered neutron double differential albedo ii) The points of entry and exit of the neutron in the duct wall may be considered the same for the multiscattered neutrons. For a punctual source at the mouth of the duct, we have determined the direct and the reflected part of the total thermal neutron flux at the exit of the duct for different lengths and different radius of the duct. For a punctual source, we have found that the major contribution to the total flux of neutrons at the exit is due to the neutron reflection by walls and the reflection contribution decreases when the neutron energy decreases. For a constant length of the duct, the reflected part decreases when the duct radius increases while for the disk shaped source we have found the opposite phenomena. The transmitted neutron flux distribution at the exit of the duct are determined for disk shaped source for different neutron energy and for different distance from the exit center. (author)

The inaccuracy of heat transfer characteristics of insulated and non-insulated circular duct while neglecting the influence of heat radiation

International Nuclear Information System (INIS)

Hsien, T.-L.; Wong, K.-L.; Yu, S.-J.

2009-01-01

The non-insulated and insulated ducts are commonly applied in the industries and various buildings, because the heat radiation equation contains the 4th order exponential of temperature which is very complicate in calculations. Most heat transfer experts recognized from their own experiences that the heat radiation effect can be ignored due to the small temperature difference between insulated and non-insulated surface and surroundings. This paper studies in detail to check the inaccuracies of heat transfer characteristics non-insulated and insulated duct by comparing the results between considering and neglecting heat radiation effect. It is found that neglecting the heat radiation effect is likely to produce large errors of non-insulated and thin-insulated ducts in situations of ambient air with low external convection heat coefficients and larger surface emissivity, especially while the ambient air temperature is different from that of surroundings and greater internal fluid convection coefficients. It is also found in this paper that using greater duct surface emissivity can greatly improve the heat exchanger effect and using smaller insulated surface emissivity can obtain better insulation.

Experimental Analysis on Solar Desiccant Air Conditioner

OpenAIRE

Dr. U. V. Kongre, C. M. Singh, A. B. Biswas

2014-01-01

The experiment investigated and evaluated the feasibility of an solar desiccant air conditioner. Its effectiveness as a possible air conditioner option used in household air conditioner or as an energy efficient and environmentally friendly alternative to conventional air conditioning units used in houses are evaluated. A solar water heater was used as heat gain. The model utilizes the technology of solar air conditioner system. The purpose in the long term wou...

Feasibility of using electrical downhole heaters in Faja heavy oil reservoirs

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, R.; Bashbush, J.L.; Rincon, A. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Schlumberger, Sugar Land, TX (United States)

2008-10-15

Numerical models were used to examine the effect of downhole heaters in enhanced oil recovery (EOR) processes in Venezuela's Orinoco reservoir. The downhole heaters were equipped with mineral-insulated cables that allowed alternating currents to flow between 2 conductors packed in a resistive core composed of polymers and graphite. The heaters were used in conjunction with steam assisted gravity drainage (SAGD) processes and also used in horizontal wells for limited amounts of time in order to accelerate production and pressure declines. The models incorporated the petrophysical and fluid characteristics of the Ayacucho area in the Faja del Orinoco. A compositional-thermal simulator was used to describe heat and fluid flow within the reservoir. A total of 8 scenarios were used to examine the electrical heaters with horizontal and vertical wells with heaters of various capacities. Results of the study were then used in an economic analysis of capitalized and operating costs. Results of the study showed that downhole heaters are an economically feasible EOR option for both vertical and horizontal wells. Use of the heaters prior to SAGD processes accelerated production and achieved higher operational efficiencies. 5 refs., 9 tabs., 15 figs.

Vitellointestinal Duct Anomalies in Infancy

OpenAIRE

Kadian, Yogender Singh; Verma, Anjali; Rattan, Kamal Nain; Kajal, Pardeep

2016-01-01

Background: Vitellointestinal duct (VID) or omphalomesenteric duct anomalies are secondary to the persistence of the embryonic vitelline duct, which normally obliterates by weeks 5–9 of intrauterine life. Methods: This is a retrospective analysis of a total of 16 patients of symptomatic remnants of vitellointestinal duct from period of Jan 2009 to May 2013. Results: Male to female ratio (M:F) was 4.3:1 and mean age of presentation was 2 months and their mode of presentation was: paten...

Gravity and Heater Size Effects on Pool Boiling Heat Transfer

Science.gov (United States)

Kim, Jungho; Raj, Rishi

2014-01-01

The current work is based on observations of boiling heat transfer over a continuous range of gravity levels between 0g to 1.8g and varying heater sizes with a fluorinert as the test liquid (FC-72/n-perfluorohexane). Variable gravity pool boiling heat transfer measurements over a wide range of gravity levels were made during parabolic flight campaigns as well as onboard the International Space Station. For large heaters and-or higher gravity conditions, buoyancy dominated boiling and heat transfer results were heater size independent. The power law coefficient for gravity in the heat transfer equation was found to be a function of wall temperature under these conditions. Under low gravity conditions and-or for smaller heaters, surface tension forces dominated and heat transfer results were heater size dependent. A pool boiling regime map differentiating buoyancy and surface tension dominated regimes was developed along with a unified framework that allowed for scaling of pool boiling over a wide range of gravity levels and heater sizes. The scaling laws developed in this study are expected to allow performance quantification of phase change based technologies under variable gravity environments eventually leading to their implementation in space based applications.

Air Conditioner/Dehumidifier

Science.gov (United States)

1986-01-01

An ordinary air conditioner in a very humid environment must overcool the room air, then reheat it. Mr. Dinh, a former STAC associate, devised a heat pipe based humidifier under a NASA Contract. The system used heat pipes to precool the air; the air conditioner's cooling coil removes heat and humidity, then the heat pipes restore the overcooled air to a comfortable temperature. The heat pipes use no energy, and typical savings are from 15-20%. The Dinh Company also manufactures a "Z" coil, a retrofit cooling coil which may be installed on an existing heater/air conditioner. It will also provide free hot water. The company has also developed a photovoltaic air conditioner and solar powered water pump.

40 CFR Table 4 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Hydrogen Chloride Emission Limits

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Operating Limits for Boilers and Process Heaters With Hydrogen Chloride Emission Limits 4 Table 4 to Subpart DDDDD of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS...

Field Performance of Heat Pump Water Heaters in the Northeast

Energy Technology Data Exchange (ETDEWEB)

Shapiro, Carl [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

2016-02-01

Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads.

Optimal and Learning-Based Demand Response Mechanism for Electric Water Heater System

Directory of Open Access Journals (Sweden)

Bo Lin

2017-10-01

Full Text Available This paper investigates how to develop a learning-based demand response approach for electric water heater in a smart home that can minimize the energy cost of the water heater while meeting the comfort requirements of energy consumers. First, a learning-based, data-driven model of an electric water heater is developed by using a nonlinear autoregressive network with external input (NARX using neural network. The model is updated daily so that it can more accurately capture the actual thermal dynamic characteristics of the water heater especially in real-life conditions. Then, an optimization problem, based on the NARX water heater model, is formulated to optimize energy management of the water heater in a day-ahead, dynamic electricity price framework. A genetic algorithm is proposed in order to solve the optimization problem more efficiently. MATLAB (R2016a is used to evaluate the proposed learning-based demand response approach through a computational experiment strategy. The proposed approach is compared with conventional method for operation of an electric water heater. Cost saving and benefits of the proposed water heater energy management strategy are explored.

Particle deposition from turbulent flow: Review of published research and its applicability to ventilation ducts in commercial buildings

Energy Technology Data Exchange (ETDEWEB)

Sippola, Mark R.; Nazaroff, William W.

2002-06-01

This report reviews published experimental and theoretical investigations of particle deposition from turbulent flows and considers the applicability of this body of work to the specific case of particle deposition from flows in the ducts of heating, ventilating and air conditioning (HVAC) systems. Particle deposition can detrimentally affect the performance of HVAC systems and it influences the exposure of building occupants to a variety of air pollutants. The first section of this report describes the types of HVAC systems under consideration and discusses the components, materials and operating parameters commonly found in these systems. The second section reviews published experimental investigations of particle deposition rates from turbulent flows and considers the ramifications of the experimental evidence with respect to HVAC ducts. The third section considers the structure of turbulent airflows in ventilation ducts with a particular emphasis on turbulence investigations that have been used as a basis for particle deposition models. The final section reviews published literature on predicting particle deposition rates from turbulent flows.

Patent arterial duct

Directory of Open Access Journals (Sweden)

Martin Robin P

2009-07-01

Full Text Available Abstract Patent arterial duct (PAD is a congenital heart abnormality defined as persistent patency in term infants older than three months. Isolated PAD is found in around 1 in 2000 full term infants. A higher prevalence is found in preterm infants, especially those with low birth weight. The female to male ratio is 2:1. Most patients are asymptomatic when the duct is small. With a moderate-to-large duct, a characteristic continuous heart murmur (loudest in the left upper chest or infraclavicular area is typical. The precordium may be hyperactive and peripheral pulses are bounding with a wide pulse pressure. Tachycardia, exertional dyspnoea, laboured breathing, fatigue or poor growth are common. Large shunts may lead to failure to thrive, recurrent infection of the upper respiratory tract and congestive heart failure. In the majority of cases of PAD there is no identifiable cause. Persistence of the duct is associated with chromosomal aberrations, asphyxia at birth, birth at high altitude and congenital rubella. Occasional cases are associated with specific genetic defects (trisomy 21 and 18, and the Rubinstein-Taybi and CHARGE syndromes. Familial occurrence of PAD is uncommon and the usual mechanism of inheritance is considered to be polygenic with a recurrence risk of 3%. Rare families with isolated PAD have been described in which the mode of inheritance appears to be dominant or recessive. Familial incidence of PAD has also been linked to Char syndrome, familial thoracic aortic aneurysm/dissection associated with patent arterial duct, and familial patent arterial duct and bicuspid aortic valve associated with hand abnormalities. Diagnosis is based on clinical examination and confirmed with transthoracic echocardiography. Assessment of ductal blood flow can be made using colour flow mapping and pulsed wave Doppler. Antenatal diagnosis is not possible, as PAD is a normal structure during antenatal life. Conditions with signs and symptoms of

PWR pressurizer with heaters well which can be obturate and sealing process

International Nuclear Information System (INIS)

Godin, B.; Guicherd, L.

1991-01-01

Each heater well is prolongated at the end located outer the pressurizer containment by a sleeve internally tapped which is prolongated at the other end by a guiding and fixation sleeve for welding the heater. The heater well can be obturated by a threaded plug introduce in the tapped part of the sleeve after cutting the welding sleeve and extraction of the heater [fr

A Numerical Study on the Light-Weight Design of PTC Heater for an Electric Vehicle Heating System

Directory of Open Access Journals (Sweden)

Hyun Sung Kang

2018-05-01

Full Text Available As the market for electric vehicles grows at a remarkable rate, various models of electric vehicles are currently in development, in parallel to the commercialization of components for diverse types of power supply. Cabin heating and heat management components are essential to electric vehicles. Any design for such components must consider the requirements for heating capacity and power density, which need to reflect both the power source and weight reduction demand of any electric vehicle. In particular, design developments in electric heaters have predominantly focused on experimental values because of structural characteristics of the heater and the variability of heat sources, requiring considerable cost and duration. To meet the ever-changing demands of the market, an improved design process for more efficient models is essential. To improve the efficacy of the design process for electric heaters, this study conducted a Computational Fluid Dynamics (CFD analysis of an electric heater with specific dimensions by changing design parameters and operating conditions of key components. The CFD analysis modeled heat characteristics through the application of user-defined functions (UDFs to reflect temperature properties of Positive Temperature Coefficient (PTC elements, which heat an electric heater. Three analysis models, which included fin as well as PTC elements and applied different spaces between the heat rods, were compared in terms of heating performance. In addition, the heat performance and heat output density of each analysis model was analyzed according to the variation of air flow at the inlet of the radiation section of an electric heater. Model B was selected, and a prototype was fabricated based on the model. The performance of the prototype was evaluated, and the correlation between the analysis results and the experimental ones was identified. The error rate between performance change rates was approximately 4%, which indicated

40 CFR 63.7506 - Do any boilers or process heaters have limited requirements?

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Do any boilers or process heaters have..., and Institutional Boilers and Process Heaters General Compliance Requirements § 63.7506 Do any boilers or process heaters have limited requirements? (a) New or reconstructed boilers and process heaters in...

How to reduce risk of climate change: Domestic hot water production methanization and programmed timing of heaters

International Nuclear Information System (INIS)

Silvestrini, G.

1992-01-01

This paper first identifies a significant and deleterious trend, in terms of poor energy efficiency and high carbon dioxide emissions, towards the increased use of electric water heaters for sanitary hot water production in single family units. It then points out how the use of wall mounted methane fired boilers can result in overall energy savings (overall electric power consumption for domestic hot water production is estimated to represent one- quarter of Italy's total domestic power demand), as well as air pollution abatement. The feasibility of other methods of energy conservation and pollution abatement in domestic water heating are also examined. These include the use of solar hot water heaters, computerized timers which allow users to program the operation of their heating plants, and the adoption by residential communities of methane fuelled district heating plants

Eversion Bile Duct Anastomosis: A Safe Alternative for Bile Duct Size Discrepancy in Deceased Donor Liver Transplantation.

Science.gov (United States)

Leal-Leyte, Pilar; McKenna, Greg J; Ruiz, Richard M; Anthony, Tiffany L; Saracino, Giovanna; Giuliano, Testa; Klintmalm, Goran B; Kim, Peter Tw

2018-04-10

Introduction Bile duct size discrepancy in liver transplantation may increase the risk of biliary complications. The aim of this study was to evaluate the safety and outcomes of the eversion bile duct anastomosis technique in deceased donor liver transplantation (DDLT) with duct to duct anastomosis. Methods A total of 210 patients who received a DDLT with duct to duct anastomosis from 2012 to 2017 were divided into two groups: those who had eversion bile duct anastomosis (N=70) and standard bile duct anastomosis (N=140). Biliary complications rates were compared between the two groups. Results There was no difference in the cumulative incidence of biliary strictures (P=0.20) and leaks (P=0.17) between the two groups. The biliary complication rate in the eversion group was 14.3% and 11.4% in the standard anastomosis group. All the biliary complications in the eversion group were managed with endoscopic stenting. A severe size mismatch (≥3:1 ratio) was associated with a significantly higher incidence of biliary strictures (44.4%) compared to 2:1 ratio (8.2%), (P=0.002). Conclusion The use of the eversion technique is a safe alternative for bile duct discrepancy in deceased donor liver transplantation; however, severe bile duct size mismatch may be a risk factor for biliary strictures with such technique. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

An overview of the development of solar water heater industry in China

International Nuclear Information System (INIS)

Runqing, Hu; Peijun, Sun; Zhongying, Wang

2012-01-01

This article introduce the development of China solar water heater industry .Gives an overview of stages, market, manufacturing, application and testing about China solar water heater industry. Show the market data from 1998 to 2009. Analyze the experiences and features about the industry. The article also introduces the policy for solar hot water industry in China. These policies have accelerated the development of industry in which the main two incentive policies have the greatest influence on solar water heater industry. First one is the policy of mandatory installation of solar water heater implemented since 2007 by some local governments at provincial and municipal levels. Second is the subsidy policy for solar water heaters in the household appliances going to the countryside scheme implemented since 2009. At last the article gives the reason why China solar water heater industry have so rapid growth. From technology research, industrialization, prices and policy environment gives analysis. - Highlights: ► We compared International and China market about solar thermal products. ► The reason for rapid development of China solar water heater is explained. ► The experience of China solar water heater industry would give reference to other develop country. ► “Meet the demands of customer” is the main driver for the solar water heater industry development. ► The policy framework about China solar thermal industry was introduced. The industry achieved commercial operation without subsidy.

Structural Benchmark Testing for Stirling Convertor Heater Heads

Science.gov (United States)

Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.

2007-01-01

The National Aeronautics and Space Administration (NASA) has identified high efficiency Stirling technology for potential use on long duration Space Science missions such as Mars rovers, deep space missions, and lunar applications. For the long life times required, a structurally significant design limit for the Stirling convertor heater head is creep deformation induced even under relatively low stress levels at high material temperatures. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and much creep data is available for the proposed Inconel-718 (IN-718) and MarM-247 nickel-based superalloy materials of construction. However, very little experimental creep information is available that directly applies to the atypical thin walls, the specific microstructures, and the low stress levels. In addition, the geometry and loading conditions apply multiaxial stress states on the heater head components, far from the conditions of uniaxial testing. For these reasons, experimental benchmark testing is underway to aid in accurately assessing the durability of Stirling heater heads. The investigation supplements uniaxial creep testing with pneumatic testing of heater head test articles at elevated temperatures and with stress levels ranging from one to seven times design stresses. This paper presents experimental methods, results, post-test microstructural analyses, and conclusions for both accelerated and non-accelerated tests. The Stirling projects use the results to calibrate deterministic and probabilistic analytical creep models of the heater heads to predict their life times.

A study of air breathing rockets. 3: Supersonic mode combustors

Science.gov (United States)

Masuya, G.; Chinzel, N.; Kudo, K.; Murakami, A.; Komuro, T.; Ishii, S.

An experimental study was made on supersonic mode combustors of an air breathing rocket engine. Supersonic streams of room-temperature air and hot fuel-rich rocket exhaust were coaxially mixed and burned in a concially diverging duct of 2 deg half-angle. The effect of air inlet Mach number and excess air ratio was investigated. Axial wall pressure distribution was measured to calculate one dimensional change of Mach number and stagnation temperature. Calculated results showed that supersonic combustion occurred in the duct. At the exit of the duct, gas sampling and Pitot pressure measurement was made, from which radial distributions of various properties were deduced. The distribution of mass fraction of elements from rocket exhaust showed poor mixing performance in the supersonic mode combustors compared with the previously investigated cylindrical subsonic mode combustors. Secondary combustion efficiency correlated well with the centerline mixing parameter, but not with Annushkin's non-dimensional combustor length. No major effect of air inlet Mach number or excess air ratio was seen within the range of conditions under which the experiment was conducted.

Compact instantaneous water heater

Energy Technology Data Exchange (ETDEWEB)

Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

2012-07-01

This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

Ultrathin Polyimide-Stainless Steel Heater for Vacuum System Bake-out

CERN Document Server

Rathjen, Christian; Henrist, Bernard; Kölemeijer, Wilhelmus; Libera, Bruno; Lutkiewicz, Przemyslaw

2005-01-01

Space constraints in several normal conducting magnets of the LHC required the development of a dedicated permanent heater for vacuum chamber bake-out. The new heater consists of stainless steel bands inside layers of polyimide. The overall heater thickness is about 0.3 mm. The low magnetic permeability is suitable for applications in magnetic fields. The material combination allows for temperatures high enough to activate a NEG coating. Fabrication is performed in consecutive steps of tape wrapping. Automation makes high volume production at low costs possible. About 800 m of warm vacuum system of the long straight sections of the LHC will be equipped with the new heater. This paper covers experience gained at CERN from studies up to industrialization.

Performance Analysis of a Modular Small-Diamter Air Distribution System

Energy Technology Data Exchange (ETDEWEB)

Poerschke, Andrew [IBACOS, Inc., Pitsburgh, PA (United States); Rudd, Armin [ABT Systems, LLC, Annville, PA (United States)

2016-03-01

This report investigates the feasibility of using a home-run manifold small-diameter duct system to provide space conditioning air to individual thermal zones in a low-load home. This compact layout allows duct systems to be brought easily within conditioned space via interior partition walls. Centrally locating the air handler unit in the house significantly reduces duct lengths. The plenum box is designed so that each connected duct receives an equal amount of airflow, regardless of the duct position on the box. Furthermore, within a reasonable set of length restrictions, each duct continues to receive similar airflow. The design method uses an additive approach to reach the total needed zonal airflow. Once the cubic feet per minute needed to satisfy the thermal load of a zone has been determined, the total number of duct runs to a zone can be calculated by dividing the required airflow by the standard airflow from each duct. The additive approach greatly simplifies the design effort and reduces the potential for duct design mistakes to be made. Measured results indicate that this plenum design can satisfy the heating load. However, the total airflow falls short of satisfying the cooling load in a hypothetical building. Static pressure inside the plenum box of 51.5 Pa limited the total airflow of the attached mini-split heat pump blower, thus limiting the total thermal capacity. Fan energy consumption is kept to 0.16 to 0.22 watt/CFM by using short duct runs and smooth duct material.

Bile Duct Adenoma with Oncocytic Features

Directory of Open Access Journals (Sweden)

E. J. Johannesen

2014-01-01

Full Text Available Bile duct adenomas are benign bile duct proliferations usually encountered as an incidental finding. Oncocytic bile duct neoplasms are rare and the majority are malignant. A 61-year-old male with a diagnosis of colorectal adenocarcinoma was undergoing surgery when a small white nodule was discovered on the surface of the right lobe of his liver. This lesion was composed of cytologically bland cells arranged in tightly packed glands. These cells were immunopositive for cytokeratin 7, negative for Hep Par 1, contained mucin, and had a Ki67 proliferation index of 8%. The morphology, immunophenotype, presence of mucin, and normal appearing bile ducts, as well as the increased Ki67 proliferation rate, were consistent with a bile duct adenoma with oxyphilic (oncocytic change. Oncocytic tumors in the liver are rare; the first described in 1992. Only two bile duct adenomas with oncocytic change have been reported and neither of them had reported mucin production or the presence of normal appearing bile ducts within the lesion.

Endolymphatic Thoracic Duct Stent-Graft Reconstruction for Chylothorax: Approach, Technical Success, Safety, and Short-term Outcomes.

Science.gov (United States)

Srinivasa, Rajiv N; Chick, Jeffrey Forris Beecham; Hage, Anthony N; Gemmete, Joseph J; Murrey, Douglas C; Srinivasa, Ravi N

2018-04-01

To report approach, technical success, safety, and short-term outcomes of thoracic duct stent-graft reconstruction for the treatment of chylothorax. Two patients, 1 (50%) male and 1 (50%) female, with mean age of 38 years (range: 16-59 years) underwent endolymphatic thoracic duct stent-graft reconstruction between September 2016 and July 2017. Patients had radiographic left-sided chylothoraces (n = 2) from idiopathic causes (n = 1) and heart transplantation (n = 1). In both (100%) patients, antegrade lymphatic access was used to opacify the thoracic duct after which retrograde access was used for thoracic duct stent-graft placement. Pelvic lymphangiography technical success, antegrade cisterna chyli cannulation technical success, thoracic duct opacification technical success, retrograde thoracic duct access technical success, thoracic duct stent-graft reconstruction technical success, ethiodized oil volume, contrast volume, estimated blood loss, procedure time, fluoroscopy time, radiation dose, clinical success, complications, deaths, and follow-up were recorded. Pelvic lymphangiography, antegrade cisterna chyli cannulation, thoracic duct opacification, retrograde thoracic duct access, and thoracic duct stent-graft reconstruction were technically successful in both (100%) patients. Mean ethiodized oil volume was 8 mL (range: 5-10 mL). Mean contrast volume was 13 mL (range: 5-20 mL). Mean estimated blood loss was 13 mL (range: 10-15 mL). Mean fluoroscopy time was 50.4 min (range: 31.2-69.7 min). Mean dose area product and reference air kerma were 954.4 μGmy 2 (range: 701-1,208 μGmy 2 ) and 83.5 mGy (range: 59-108 mGy), respectively. Chylothorax resolved in both (100%) patients. There were no minor or major complications directly related to the procedure. Thoracic duct stent-graft reconstruction may be a technically successful and safe alternative to thoracic duct embolization, disruption, and surgical ligation for the treatment of chylothorax

High-Temperature Compatible Nickel Silicide Thermometer And Heater For Catalytic Chemical Microreactors

DEFF Research Database (Denmark)

Jensen, Søren; Quaade, U.J.; Hansen, Ole

2005-01-01

Integration of heaters and thermometers is important for agile and accurate control and measurement of the thermal reaction conditions in microfabricated chemical reactors (microreactors). This paper describes development and operation of nickel silicide heaters and temperature sensors...... for temperatures exceeding 700 °C. The heaters and thermometers are integrated with chemical microreactors for heterogeneous catalytic conversion of gasses, and thermally activated catalytic conversion of CO to CO2 in the reactors is demonstrated. The heaters and thermometers are shown to be compatible...

SINGLE HEATER TEST FINAL REPORT

International Nuclear Information System (INIS)

J.B. Cho

1999-01-01

The Single Heater Test is the first of the in-situ thermal tests conducted by the U.S. Department of Energy as part of its program of characterizing Yucca Mountain in Nevada as the potential site for a proposed deep geologic repository for the disposal of spent nuclear fuel and high-level nuclear waste. The Site Characterization Plan (DOE 1988) contained an extensive plan of in-situ thermal tests aimed at understanding specific aspects of the response of the local rock-mass around the potential repository to the heat from the radioactive decay of the emplaced waste. With the refocusing of the Site Characterization Plan by the ''Civilian Radioactive Waste Management Program Plan'' (DOE 1994), a consolidated thermal testing program emerged by 1995 as documented in the reports ''In-Situ Thermal Testing Program Strategy'' (DOE 1995) and ''Updated In-Situ Thermal Testing Program Strategy'' (CRWMS M and O 1997a). The concept of the Single Heater Test took shape in the summer of 1995 and detailed planning and design of the test started with the beginning fiscal year 1996. The overall objective of the Single Heater Test was to gain an understanding of the coupled thermal, mechanical, hydrological, and chemical processes that are anticipated to occur in the local rock-mass in the potential repository as a result of heat from radioactive decay of the emplaced waste. This included making a priori predictions of the test results using existing models and subsequently refining or modifying the models, on the basis of comparative and interpretive analyses of the measurements and predictions. A second, no less important, objective was to try out, in a full-scale field setting, the various instruments and equipment to be employed in the future on a much larger, more complex, thermal test of longer duration, such as the Drift Scale Test. This ''shake down'' or trial aspect of the Single Heater Test applied not just to the hardware, but also to the teamwork and cooperation between

Radiation resistant ducted superconductive coil

International Nuclear Information System (INIS)

Schleich, A.

1976-01-01

The radiation-resistant ducted superconductive coil consists of a helically wound electrical conductor constituted by an electrically conductive core of superconductive material provided with a longitudinally extending cooling duct. The core is covered with a layer of inorganic insulating material and the duct is covered by an electrically conductive metallic gas-tight sheath. The metallic sheaths on adjacent turns of the coil are secured together. 2 Claims, 4 Drawing Figures

Vibrational response of a rectangular duct of finite length excited by a turbulent internal flow

Science.gov (United States)

David, Antoine; Hugues, Florian; Dauchez, Nicolas; Perrey-Debain, Emmanuel

2018-05-01

Gas transport ductwork in industrial plants or air conditioning networks can be subject to vibrations induced by the internal flow. Most studies in this matter have been carried out on circular ducts. This paper focuses specifically on the vibratory response of a rectangular duct of finite length excited by an internal turbulent flow. A semi-analytical model taking into account the modal response of the structure due to both aerodynamic and acoustic contributions is derived. The aerodynamic component of the excitation is applied on the basis of Corcos model where the power spectral density of the wall pressure is determined experimentally. The acoustic component is based on the propagating modes in the duct where the acoustic modal contribution are extracted via cross-spectral densities. The vibrational response is given for a 0.2 × 0.1 × 0.5 m3 duct made of 3 mm steel plates excited by 20 m/s or 30 m/s flows. Comparisons between experimental results and numerical predictions show a good agreement. The competition between acoustic and aerodynamic components is highlighted.

Numerical model describing the heat transfer between combustion products and ventilation-system duct walls

International Nuclear Information System (INIS)

Bolstad, J.W.; Foster, R.D.; Gregory, W.S.

1983-01-01

A package of physical models simulating the heat transfer processes occurring between combustion gases and ducts in ventilation systems is described. The purpose of the numerical model is to predict how the combustion gas in a system heats up or cools down as it flows through the ducts in a ventilation system under fire conditions. The model treats a duct with (forced convection) combustion gases flowing on the inside and stagnant ambient air on the outside. The model is composed of five submodels of heat transfer processes along with a numerical solution procedure to evaluate them. Each of these quantities is evaluated independently using standard correlations based on experimental data. The details of the physical assumptions, simplifications, and ranges of applicability of the correlations are described. A typical application of this model to a full-scale fire test is discussed, and model predictions are compared with selected experimental data

Space Station solar water heater

Science.gov (United States)

Horan, D. C.; Somers, Richard E.; Haynes, R. D.

1990-01-01

The feasibility of directly converting solar energy for crew water heating on the Space Station Freedom (SSF) and other human-tended missions such as a geosynchronous space station, lunar base, or Mars spacecraft was investigated. Computer codes were developed to model the systems, and a proof-of-concept thermal vacuum test was conducted to evaluate system performance in an environment simulating the SSF. The results indicate that a solar water heater is feasible. It could provide up to 100 percent of the design heating load without a significant configuration change to the SSF or other missions. The solar heater system requires only 15 percent of the electricity that an all-electric system on the SSF would require. This allows a reduction in the solar array or a surplus of electricity for onboard experiments.

Protection Heater Design Validation for the LARP Magnets Using Thermal Imaging

CERN Document Server

Marchevsky, M; Cheng, D W; Felice, H; Sabbi, G; Salmi, T; Stenvall, A; Chlachidze, G; Ambrosio, G; Ferracin, P; Izquierdo Bermudez, S; Perez, J C; Todesco, E

2016-01-01

Protection heaters are essential elements of a quench protection scheme for high-field accelerator magnets. Various heater designs fabricated by LARP and CERN have been already tested in the LARP high-field quadrupole HQ and presently being built into the coils of the high-field quadrupole MQXF. In order to compare the heat flow characteristics and thermal diffusion timescales of different heater designs, we powered heaters of two different geometries in ambient conditions and imaged the resulting thermal distributions using a high-sensitivity thermal video camera. We observed a peculiar spatial periodicity in the temperature distribution maps potentially linked to the structure of the underlying cable. Two-dimensional numerical simulation of heat diffusion and spatial heat distribution have been conducted, and the results of simulation and experiment have been compared. Imaging revealed hot spots due to a current concentration around high curvature points of heater strip of varying cross sections and visuali...

Remote Visual Testing (RVT) for the diagnostic inspection of feedwater heaters

International Nuclear Information System (INIS)

Nugent, M.J.; Pellegrino, B.A.

1993-01-01

Feedwater heaters are an important component in the overall plant heat rate, reliability, availability, performance and maintenance considerations at power stations. The ability to diagnose heater problems in-situ properly can lead to: (1) Preventative plugging of damaged, but unfailed tubes; (2) In-place repair procedures; (3) Incorporation of corrective actions into replacement designs or heater/unit operations. The benefits and limitations of Non-Destructive Testing (NDT) on feedwater heaters are briefly reviewed. All Remote Visual Testing (RVT) including borescopes, fiberscopes, videoborescopes and Closed Circuit Television (CCTV) cameras are discussed along with currently accepted formats for documentation. The benefits of a comprehensive in-place inspection involving Remote Visual Testing are discussed in relationship to its diagnostic capabilities. The results of eight post-service heater inspections are discussed along with the root cause of failure of seven unique failure mechanisms. These inspections, including FWH access, RVT tool and data analysis, are detailed. 13 figs

Integrated collector-storage solar water heater with extended storage unit

International Nuclear Information System (INIS)

Kumar, Rakesh; Rosen, Marc A.

2011-01-01

The integrated collector-storage solar water heater (ICSSWH) is one of the simplest designs of solar water heater. In ICSSWH systems the conversion of solar energy into useful heat is often simple, efficient and cost effective. To broaden the usefulness of ICSSWH systems, especially for overnight applications, numerous design modifications have been proposed and analyzed in the past. In the present investigation the storage tank of an ICSSWH is coupled with an extended storage section. The total volume of the modified ICSSWH has two sections. Section A is exposed to incoming solar radiation, while section B is insulated on all sides. An expression is developed for the natural convection flow rate in section A. The inter-related energy balances are written for each section and solved to ascertain the impact of the extended storage unit on the water temperature and the water heater efficiency. The volumes of water in the two sections are optimized to achieve a maximum water temperature at a reasonably high efficiency. The influence is investigated of inclination angle of section A on the temperature of water heater and the angle is optimized. It is determined that a volume ratio of 7/3 between sections A and B yields the maximum water temperature and efficiency in the modified solar water heater. The performance of the modified water heater is also compared with a conventional ICSSWH system under similar conditions.

Modified nasolacrimal duct stenting

International Nuclear Information System (INIS)

Tian Min; Jin Mei; Chen Huanjun; Li Yi

2008-01-01

Objective: Traditional nasolacrimal duct stenting possesses some shortcoming including difficulty of pulling ball head guide wire from the nasal cavity with turbinate hypertrophy and nasal septal deviation. The new method of nose-oral tube track establishment can overcome the forementioned and increase the successful rate. Methods: 5 F catheter and arterial sheath were modified to be nasolacrimal duct stent delivery device respectively. Antegrade dacryocystography was taken firstly to display the obstructed site and followed by the modified protocol of inserting the guide wire through nasolacrimal duct and nasal cavity, and establishing the stent delivery track for retrograde stent placement. Results: 5 epiphora patients with failure implantation by traditional method were all succeeded through the modified stenting (100%). During 6-mouth follow-up, no serious complications and reocclusion occurred. Conclusion: The establishment of eye-nose-mouth-nose of external nasal guide wire track can improve the successful rate of nasolacrimal duct stenting. (authors)

The "flying" bile duct: avulsion of the common bile duct in a plane crash survivor.

LENUS (Irish Health Repository)

Mohan, H

2012-02-01

Blunt trauma is an unusual cause of extrahepatic bile duct injury. This is a case of a 51-year-old gentleman who sustained a significant seatbelt injury in a plane crash. Laparotomy, performed due to persistent abdominal pain, revealed that the common bile duct (CBD) was completely avulsed from the duodenum. Following insertion of drains and transfer to a hepatobiliary centre, the devascularised CBD was excised and replaced with a roux-en-y hepaticojejunostomy. Necrotic tissue was debrided from the pancreatic head. A persistent bile leak developed from the sub-hepatic drain. Repeat laparotomy revealed a bile leak from small ducts on the liver surface. Ligation of the ducts and bioglue sealing of the area were successfully performed. Subsequent to this a pancreatic fistula developed from the main pancreatic duct, which has since resolved. This unusual case illustrates the need for prompt recognition and early repair to optimise outcomes in traumatic CBD injury.

Management of aging of water heaters in nuclear power plants

International Nuclear Information System (INIS)

Martin-Serrano Ledesma, C.; Toro del toro, J.; Real Rubio, I.; Garcia Montejano, A.

2014-01-01

The scope of this work includes the study of all feedwater heaters (from 1 to 6) in their two trains (A and B). In this study the main degradation phenomena that affect them, the operating parameters that can warn of a possible malfunction of the heater and possible strategies inspection, repair and replacement are analyzed. As a result of this study, a higher priority is obtained at a lower state of degradation of the heaters, possibly with a strategy inspection, repair or replacement, for each recharge, until the end of life of the plant. This will be a live program, which must be fed back to the studies of the parameters of operation of the heater during operation and results of the inspection of each recharge. May verify the effectiveness of aging management program using different indicators. (Author)

Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

OpenAIRE

Toffoli, Valeria; Carrato, Sergio; Lee, Dongkyu; Jeon, Sangmin; Lazzarino, Marco

2013-01-01

The design and characteristics of a micro-system for thermogravimetric analysis (TGA) in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using mill...

Duct having oscillatory side wall

Science.gov (United States)

Sprouse, Kenneth M.

2018-04-03

A pump system includes a particulate consolidator pump that has a pump outlet. A duct is coupled to the pump outlet. The duct has a wall that is coupled with an oscillator. The oscillator is operable to oscillate the wall at a controlled frequency. The controlled frequency is selected with respect to breaking static bridging of particulate in the duct due, at least in part, to consolidation of the particulate from a downstream check valve.

Studies on ultraviolet inactivation of air-borne microorganisms, 1

International Nuclear Information System (INIS)

Adachi, Shin-ichi; Doi, Hitoshi; Yamayoshi, Takao; Nunoura, Masako; Tatsumi, Noriyuki.

1989-01-01

UV(254nm) inactivation of air-borne bacteria in an air-controlling apparatus was studied. The appratus was composed of a chamber for vaporizing a bacterial suspension and an irradiation duct equipped with an UV lamp(GL-30). The bacterial which passed through the irradiation duct impinged on a petri dish by an air slit sampler. Selected bacteria for the experiment were Serratia marcescens, Escherichia coli, Sarcina lutea and Bacillus subtilis(spores). The apparatus was useful for the study of the susceptibility of air-borne bacteria to UV radiation. UV dose necessary to inhibit colony formation in 90% of individual bacteria in the controlled air was as low as 27 to 35% of the dose required for the agar plate method. (author)

The correlation between the dilated extent of bile duct and gallbladder and low bile duct obstructive jaundice diseases

International Nuclear Information System (INIS)

Wang Zhongqiu; Lu Guangming; Li Jieshou; Li Weiqin

2005-01-01

Objective: To evaluate the diagnostic value about the dilated extent of bile duct and gallbladder in low biliary obstructive diseases. Methods: CT and ERCP findings of 105 patients with low biliary obstructive disease were retrospectively analyzed. The dilated extent of intrahepatic and extra- hepatic bile duct and gallbladder were classified into seven types: Type I: severe dilatation of intrahepatic and extrahepatic bile duct and gallbladder; Type II: severe dilatation of extrahepatic bile duct and gallbladder and slight dilated intrahapetic bile duct; Type III: severe dilatation of intrahepatic and extrahepatic bile duct without or slight dilatation of gallbladder; Type IV: severe extrahepatic bile duct dilatation without or slight dilatation of intrahepatic bile duct and gallbladder; Type V: severe intrahepatic bile duct dilatation without or with slight dilatation of extrahepatic bile duct and gallbladder; Type VI: severe gallbladder dilatation without or with slight intrahepatic and extra- hepatic bile duct dilatation; Type VII: without or with slight dilatation of intrahepatic and extrahepatic bile duct and gallbladder. The biliary system dilated extent of low biliary obstructive disease on CT and ERCP were compared with results of clinical, operation, and pathology. Results: Thirty-three cases of tumor and 72 cases of non-tumor were proved by clinical and operation in 105 patients with low biliary obstructive disease. In 33 tumor patients, 16 patients were identified as Type I, 10 patients Type II, 4 patients Type III, 1 patient Type IV, 2 patients Type VII. In 72 non-tumor patients, 4 patients were identified as Type I, 4 patients Type II, 9 patients Type III, 33 patients Type IV, 2 patients Type V, 11 patients Type VI, 19 patients Type VII. A large difference between I, II type and III-VII type biliary dilatation existed in tumor and non-tumor group (χ 2 =47.33, P<0.01). Conclusion:Low obstructive biliary diseases are closely correlated with the dilated

Long-term follow-up after choledochojejunostomy for bile duct stones with complex clearance of the bile duct

NARCIS (Netherlands)

Gouma, D. J.; Konsten, J.; Soeters, P. B.; Von Meyenfeldt, M.; Obertop, H.

1989-01-01

In this retrospective study, the long-term follow-up of patients undergoing choledochojejunostomy (Roux-en-Y) for bile duct stones with complex clearance of the bile duct is evaluated. Bile duct exploration and subsequent choledochojejunostomy (Roux-en-Y) was performed in 43 patients (median age 67

Numerical analysis of thermal-hydrological conditions in the single heater test at Yucca Mountain

International Nuclear Information System (INIS)

Birkholzer, Jens T.; Tsang, Yvonne W.

1998-01-01

The Single Heater Test (SHT) is one of two in-situ thermal tests included in the site characterization program for the potential underground nuclear waste repository at Yucca Mountain. The heating phase of the SHT started in August 1996, and was completed in May 1997 after 9 months of heating. The coupled processes in the unsaturated fractured rock mass around the heater were monitored by numerous sensors for thermal, hydrological, mechanical and chemical data. In addition to passive monitoring, active testing of the rock mass moisture content was performed using geophysical methods and air injection testing. The extensive data set available from this test gives a unique opportunity to improve the understanding of the thermal-hydrological situation in the natural setting of the repository rocks. The present paper focuses on the 3-D numerical simulation of the thermal-hydrological processes in the SHT using TOUGH2. In the comparative analysis, they are particularly interested in the accuracy of different fracture-matrix-interaction concepts such as the Effective Continuum (ECM), the Dual Continuum (DKM), and the Multiple Interacting Continua (MINC) method

Evaluating The Operation Of Three Air Cleaners Working Individually In A Clean Room

DEFF Research Database (Denmark)

Ardkapan, Siamak Rahimi; Afshari, Alireza; Bergsøe, Niels Christian

2011-01-01

The use of portable air cleaners is becoming increasingly popular in many countries including Denmark. Portable air cleaners are known for not only removing but also generating particles and gases. To clarify this, three air cleaning technologies were evaluated. They were nonthermal plasma......, photochemical air purifier and corona discharge ionizer. The concentrations of ultrafine particles, ozone and total volatile organic compounds were measured both in a duct and in a clean room. It was found that the studied air cleaning technologies increased the ozone level in the clean room and the duct....... The increase of ozone level in the clean room was more than that was measured in the duct. Additionally, it was found that the number of ultrafine particles in the room increased due to the generated ozone. The number of generated particles changed with the season. The study leads to the recommendation...

Experimental study on a comparison of typical premixed combustible gas-air flame propagation in a horizontal rectangular closed duct.

Science.gov (United States)

Jin, Kaiqiang; Duan, Qiangling; Liew, K M; Peng, Zhongjing; Gong, Liang; Sun, Jinhua

2017-04-05

Research surrounding premixed flame propagation in ducts has a history of more than one hundred years. Most previous studies focus on the tulip flame formation and flame acceleration in pure gas fuel-air flame. However, the premixed natural gas-air flame may show different behaviors and pressure dynamics due to its unique composition. Natural gas, methane and acetylene are chosen here to conduct a comparison study on different flame behaviors and pressure dynamics, and to explore the influence of different compositions on premixed flame dynamics. The characteristics of flame front and pressure dynamics are recorded using high-speed schlieren photography and a pressure transducer, respectively. The results indicate that the compositions of the gas mixture greatly influence flame behaviors and pressure. Acetylene has the fastest flame tip speed and the highest pressure, while natural gas has a faster flame tip speed and higher pressure than methane. The Bychkov theory for predicting the flame skirt motion is verified, and the results indicate that the experimental data coincide well with theory in the case of equivalence ratios close to 1.00. Moreover, the Bychkov theory is able to predict flame skirt motion for acetylene, even outside of the best suitable expansion ratio range of 6

Safety grade pressurizer heater power supply connector assembly

International Nuclear Information System (INIS)

Burnett, J.M.; Daftari, R.M.; Reyns, R.M.

1987-01-01

This patent describes a pressurizer heater power supply connector assembly for attaching a power cable to an electric heater within a pressurizer of a pressurized water nuclear reactor system, the electric heater having pin contacts. The assembly comprises: a pin-socket type connector including a tubular body having a first open end carrying a pin-socket contact member and an insert intermediate a shell and the pin-socket contact member, the contact member having socket means for electrically receiving and contacting the pin contacts, and a second open end; a flexible sealed conduit including a flexible corrugated tube having one end connected to the second open end of the pin-socket type connector, and another end; and a shop splice assembly including a header adapter and a hose clamp interconnected between the header adapter and another end of the flexible corrugated tube

Nasopalatine duct cyst: A case report

Directory of Open Access Journals (Sweden)

Saikrishna Pasupuleti

2015-01-01

Full Text Available Nasopalatine duct cyst (NPDC is the most common non-odontogenic cyst of oral cavity. Clinically, Nasopalatine duct cyst manifests as an asymptomatic swelling of the palate or the upper lip. Radiographically, it is seen as a heart-shaped radiolucency and can be confused with periapical pathology. The aim of this article is to report a case of a nasopalatine duct cyst in a 36-year-old patient which was misinterpreted for a periapical cyst. Diagnosis of a Nasopalatine duct cyst can be given through clinical, radiographical, and histopathological examination.

Radiologic imaging of bile duct changes by clonorchiasis

International Nuclear Information System (INIS)

Kim, Myung Joon; Yoo, Hyung Sik; Lee, Jong Tae; Jung, Soon Hee

1988-01-01

The changes of the bile ducts were reviewed retrospectively in 38 patients of clonorchiasis by ultrasonography and/or CT. Diagnosis was made in 13 patients by cholecystectomy and exploration of the common bile duct, another 2 patients by segmentectomy and wedge resection of the liver, and 23 patients by stool examination. 14 of 36 cases done ultrasonography showed the parallel channel sign, and small nodular echoes around the dilated bile ducts. And 3 cases showed the echoes of worm of clonorchis sinensis in the common bile duct. 22 of 36 cases showed the parallel channel signs only. All cases (11) done CT showed diffuse dilatation of the peripheral bile ducts. 5 of 11 cases showed ring or tubular contrast enhancement around the dilated bile ducts. In 2 cases of liver resection, the bile ducts showed adenomatous hyperplasia and severe periductal fibrosis. Proliferation of blood vessels and infiltration of inflammatory cells were also seen. So we consider that the increased echoes of the bile duct wall, small nodular echoes around the bile ducts were attributed to the bile duct dilatation, severe adenomatous hyperplasia and periductal fibrosis. The ring or tubular contrast enhancement of the dilated bile ducts seems to be caused by the marked periductal inflammation resulting in capillary proliferation and the periductal fibrosis.

Radiologic imaging of bile duct changes by clonorchiasis

Energy Technology Data Exchange (ETDEWEB)

Kim, Myung Joon; Yoo, Hyung Sik; Lee, Jong Tae; Jung, Soon Hee [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1988-10-15

The changes of the bile ducts were reviewed retrospectively in 38 patients of clonorchiasis by ultrasonography and/or CT. Diagnosis was made in 13 patients by cholecystectomy and exploration of the common bile duct, another 2 patients by segmentectomy and wedge resection of the liver, and 23 patients by stool examination. 14 of 36 cases done ultrasonography showed the parallel channel sign, and small nodular echoes around the dilated bile ducts. And 3 cases showed the echoes of worm of clonorchis sinensis in the common bile duct. 22 of 36 cases showed the parallel channel signs only. All cases (11) done CT showed diffuse dilatation of the peripheral bile ducts. 5 of 11 cases showed ring or tubular contrast enhancement around the dilated bile ducts. In 2 cases of liver resection, the bile ducts showed adenomatous hyperplasia and severe periductal fibrosis. Proliferation of blood vessels and infiltration of inflammatory cells were also seen. So we consider that the increased echoes of the bile duct wall, small nodular echoes around the bile ducts were attributed to the bile duct dilatation, severe adenomatous hyperplasia and periductal fibrosis. The ring or tubular contrast enhancement of the dilated bile ducts seems to be caused by the marked periductal inflammation resulting in capillary proliferation and the periductal fibrosis.

Heat exchanger inventory cost optimization for power cycles with one feedwater heater

International Nuclear Information System (INIS)

Qureshi, Bilal Ahmed; Antar, Mohamed A.; Zubair, Syed M.

2014-01-01

Highlights: • Cost optimization of heat exchanger inventory in power cycles is investigated. • Analysis for an endoreversible power cycle with an open feedwater heater is shown. • Different constraints on the power cycle are investigated. • The constant heat addition scenario resulted in the lowest value of the cost function. - Abstract: Cost optimization of heat exchanger inventory in power cycles with one open feedwater heater is undertaken. In this regard, thermoeconomic analysis for an endoreversible power cycle with an open feedwater heater is shown. The scenarios of constant heat rejection and addition rates, power as well as rate of heat transfer in the open feedwater heater are studied. All cost functions displayed minima with respect to the high-side absolute temperature ratio (θ 1 ). In this case, the effect of the Carnot temperature ratio (Φ 1 ), absolute temperature ratio (ξ) and the phase-change absolute temperature ratio for the feedwater heater (Φ 2 ) are qualitatively the same. Furthermore, the constant heat addition scenario resulted in the lowest value of the cost function. For variation of all cost functions, the smaller the value of the phase-change absolute temperature ratio for the feedwater heater (Φ 2 ), lower the cost at the minima. As feedwater heater to hot end unit cost ratio decreases, the minimum total conductance required increases

Evaluation of a high-temperature burner-duct-recuperator system

Science.gov (United States)

1990-07-01

The U.S. Department of Energy's (DOE) Office of Industrial Technologies (OIT) sponsors research and development (R and D) to improve the energy efficiency of American industry and to provide for fuel flexibility. OIT has funded a multiyear R and D project by the Babcock and Wilcox Company (B and W) to design, fabricate, field test, and evaluate a high-temperature burner-duct-recuperator (HTBDR) system. This ceramic-based recuperator system recovers waste heat from the corrosive, high-temperature (2170 F) flue gas stream of a steel soaking pit to preheat combustion air to as high as 1700 F. The preheated air is supplied to a high-temperature burner. The B and W R and D program, which is now complete, involved several activities, including selecting and evaluating ceramic materials, designing the system, and developing and evaluating the prototype. In addition, a full-scale unit was tested at a B and W steel soaking pit. The full-scale system consisted of a modular single-stage ceramic recuperator, a conventional two-pass metallic recuperator, a high-temperature burner, fans, insulated ducting, and associated controls and instrumentation. The metallic recuperator preheated combustion air to about 750 F before it passed to the ceramic module. This technical case study describes the DOE/B and W recuperator project and highlights the field tests of the full-scale recuperator system. The document makes results of field tests and data analysis available to other researchers and private industry. It discusses project status, summarizes field tests, and reviews the potential effects the technology will have on energy use and system economics.

Solair heater program: solair applications study. Final report

Energy Technology Data Exchange (ETDEWEB)

1977-12-01

General Electric has designed and tested a low-cost solar system using a vacuum tube solar air heater under ERDA Contract E(11-1)-2705. This contract extension has been provided to evaluate various applications of this solar collector. The evaluation identified attractive applications, evaluated corresponding control procedures, estimated system performance, compared economically insolation and insulation, and evaluated the repackaging of off-the-shelf equipment for improved cost effectiveness. The results of this study prompted General Electric's marketing group to do a detailed commercialization study of a residential domestic water heating system using the Solair concept which has been selected as the most attractive application. Other attractive applications are space/domestic water heating and a heat pump assisted solar system/domestic water heating where the heat pump and the solar system function in parallel. A prime advantage of heated air solar systems over liquid systems is cost and longer life which results in higher BTU's/dollar. Other air system advantages are no liquid leakage problems, no toxicity of freezing problems, and less complicated equipment. A hybrid solar system has been identified that can improve the market penetration of solar energy. This system would use the existing mass of the house for energy storage thereby reducing solar cost and complexity. Adequate performance can be obtained with house temperature swings comparable to those used in nighttime setback of the thermostat. Details of this system are provided.

Ansys Benchmark of the Single Heater Test

International Nuclear Information System (INIS)

H.M. Wade; H. Marr; M.J. Anderson

2006-01-01

The Single Heater Test (SHT) is the first of three in-situ thermal tests included in the site characterization program for the potential nuclear waste monitored geologic repository at Yucca Mountain. The heating phase of the SHT started in August 1996 and was concluded in May 1997 after 9 months of heating. Cooling continued until January 1998, at which time post-test characterization of the test block commenced. Numerous thermal, hydrological, mechanical, and chemical sensors monitored the coupled processes in the unsaturated fractured rock mass around the heater (CRWMS M and O 1999). The objective of this calculation is to benchmark a numerical simulation of the rock mass thermal behavior against the extensive data set that is available from the thermal test. The scope is limited to three-dimensional (3-D) numerical simulations of the computational domain of the Single Heater Test and surrounding rock mass. This calculation supports the waste package thermal design methodology, and is developed by Waste Package Department (WPD) under Office of Civilian Radioactive Waste Management (OCRWM) procedure AP-3.12Q, Revision 0, ICN 3, BSCN 1, Calculations

Computational Fluid Dynamics Analysis of Flexible Duct Junction Box Design

Energy Technology Data Exchange (ETDEWEB)

Beach, Robert [IBACOS Inc., Pittsburgh, PA (United States); Prahl, Duncan [IBACOS Inc., Pittsburgh, PA (United States); Lange, Rich [IBACOS Inc., Pittsburgh, PA (United States)

2013-12-01

IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics (CFD) simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance. Current Air Conditioning Contractors of America (ACCA) guidance (Group 11, Appendix 3, ACCA Manual D, Rutkowski 2009) allows for unconstrained variation in the number of takeoffs, box sizes, and takeoff locations. The only variables currently used in selecting an equivalent length (EL) are velocity of air in the duct and friction rate, given the first takeoff is located at least twice its diameter away from the inlet. This condition does not account for other factors impacting pressure loss across these types of fittings. For each simulation, the IBACOS team converted pressure loss within a box to an EL to compare variation in ACCA Manual D guidance to the simulated variation. IBACOS chose cases to represent flows reasonably correlating to flows typically encountered in the field and analyzed differences in total pressure due to increases in number and location of takeoffs, box dimensions, and velocity of air, and whether an entrance fitting is included. The team also calculated additional balancing losses for all cases due to discrepancies between intended outlet flows and natural flow splits created by the fitting. In certain asymmetrical cases, the balancing losses were significantly higher than symmetrical cases where the natural splits were close to the targets. Thus, IBACOS has shown additional design constraints that can ensure better system performance.

Heater head for stirling engine

Science.gov (United States)

Corey, John A.

1985-07-09

A monolithic heater head assembly which augments cast fins with ceramic inserts which narrow the flow of combustion gas and obtains high thermal effectiveness with the assembly including an improved flange design which gives greater durability and reduced conduction loss.

Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater

Energy Technology Data Exchange (ETDEWEB)

David Yuill

2008-06-30

The following document is the final report for DE-FC26-05NT42327: Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater. This work was carried out under a cooperative agreement from the Department of Energy's National Energy Technology Laboratory, with additional funding from Keltech, Inc. The objective of the project was to improve the temperature control performance of an electric tankless water heater (TWH). The reason for doing this is to minimize or eliminate one of the barriers to wider adoption of the TWH. TWH use less energy than typical (storage) water heaters because of the elimination of standby losses, so wider adoption will lead to reduced energy consumption. The project was carried out by Building Solutions, Inc. (BSI), a small business based in Omaha, Nebraska. BSI partnered with Keltech, Inc., a manufacturer of electric tankless water heaters based in Delton, Michigan. Additional work was carried out by the University of Nebraska and Mike Coward. A background study revealed several advantages and disadvantages to TWH. Besides using less energy than storage heaters, TWH provide an endless supply of hot water, have a longer life, use less floor space, can be used at point-of-use, and are suitable as boosters to enable alternative water heating technologies, such as solar or heat-pump water heaters. Their disadvantages are their higher cost, large instantaneous power requirement, and poor temperature control. A test method was developed to quantify performance under a representative range of disturbances to flow rate and inlet temperature. A device capable of conducting this test was designed and built. Some heaters currently on the market were tested, and were found to perform quite poorly. A new controller was designed using model predictive control (MPC). This control method required an accurate dynamic model to be created and required significant tuning to the controller before good control was achieved. The MPC

Effect of duct geometry on Wells turbine performance

International Nuclear Information System (INIS)

Shaaban, S.; Abdel Hafiz, A.

2012-01-01

Highlights: ► A Wells turbine duct design in the form of venturi duct is proposed and investigated. ► Optimum duct geometry is identified. ► Up to 14% increase of the turbine power can be achieved using the optimized duct geometry. ► Up to 9% improve of the turbine efficiency is attained by optimizing the turbine duct geometry. ► The optimized duct geometry results in tangible delay of the turbine stalling point. - Abstract: Wells turbines can represent important source of renewable energy for many countries. An essential disadvantage of Wells turbines is their low aerodynamic efficiency and consequently low power produced. In order to enhance the Wells turbine performance, the present research work proposes the use of a symmetrical duct in the form of a venturi tube with turbine rotor located at throat. The effects of duct area ratio and duct angle are investigated in order to optimize Wells turbine performance. The turbine performance is numerically investigated by solving the steady 3D incompressible Reynolds Averaged Navier–Stocks equation (RANS). A substantial improve of the turbine performance is achieved by optimizing the duct geometry. Increasing both the duct area ratio and duct angle increase the acceleration and deceleration upstream and downstream the rotor respectively. The accelerating flow with thinner boundary layer thickness upstream the rotor reduces the flow separation on the rotor suction side. The downstream diffuser reduces the interaction between tip leakage flow and blade suction side. Up to 14% increase in turbine power and 9% increase in turbine efficiency are achieved by optimizing the duct geometry. On other hand, a tangible delay of the turbine stall point is also detected.

Sheathed electrical resistance heaters for nuclear or other specialized service - approved 1973

International Nuclear Information System (INIS)

Anon.

1976-01-01

This specification presents the requirements for cylindrical metal-sheathed, electrical resistance heaters with compacted mineral-oxide insulation for nuclear or other specialized service. The intended use of a sheathed heater in a specific nuclear or general application will require an evaluation by the purchaser of the compatibility of the heater assembly in the proposed application including the effects of the integrated proposed application including the effects of the integrated neutron flux, temperature, and atmosphere on the properties of the materials of construction. This specification does not include all possible specifications, standards, etc. for materials that may be used in sheathing, insulation, resistance wire, or conductors wire in nuclear environments. The requirements of this specification include only the austenitic stainless steels and nickel-based alloys for sheathing; magnesium oxide, aluminum oxide, beryllium oxide for insulation; and nickel-chromium or iron-chromium-aluminum heater elements with or without low-resistance connecting wires. The intent of this specification is to present the requirements for heaters capable of operating at sheath temperatures and heat fluxes that will limit the maximum internal heater-element temperature to 1050 0 C

Measured data from the Avery Island Site C heater test

International Nuclear Information System (INIS)

Waldman, H.; Stickney, R.G.

1984-11-01

Over the past six years, a comprehensive field testing program was conducted in the Avery Island salt mine. Three single canister heater tests were included in the testing program. Specifically, electric heaters, which simulate canisters of heat-generating nuclear waste, were placed in the floor of the Avery Island salt mine, and measurements were made of the response of the salt to heating. These tests were in operation by June 1978. One of the three heater tests, Site C, operated for a period of 1858 days and was decommissioned during July and August 1983. This data report presents the temperature and displacement data gathered during the operation and decommissioning of the Site C heater test. The purpose of this data report is to transmit the data to the scientific community. Rigorous analysis and interpretation of the data are considered beyond the scope of a data report. 6 references, 21 figures, 1 table

SINGLE HEATER TEST FINAL REPORT

Energy Technology Data Exchange (ETDEWEB)

J.B. Cho

1999-05-01

The Single Heater Test is the first of the in-situ thermal tests conducted by the U.S. Department of Energy as part of its program of characterizing Yucca Mountain in Nevada as the potential site for a proposed deep geologic repository for the disposal of spent nuclear fuel and high-level nuclear waste. The Site Characterization Plan (DOE 1988) contained an extensive plan of in-situ thermal tests aimed at understanding specific aspects of the response of the local rock-mass around the potential repository to the heat from the radioactive decay of the emplaced waste. With the refocusing of the Site Characterization Plan by the ''Civilian Radioactive Waste Management Program Plan'' (DOE 1994), a consolidated thermal testing program emerged by 1995 as documented in the reports ''In-Situ Thermal Testing Program Strategy'' (DOE 1995) and ''Updated In-Situ Thermal Testing Program Strategy'' (CRWMS M&O 1997a). The concept of the Single Heater Test took shape in the summer of 1995 and detailed planning and design of the test started with the beginning fiscal year 1996. The overall objective of the Single Heater Test was to gain an understanding of the coupled thermal, mechanical, hydrological, and chemical processes that are anticipated to occur in the local rock-mass in the potential repository as a result of heat from radioactive decay of the emplaced waste. This included making a priori predictions of the test results using existing models and subsequently refining or modifying the models, on the basis of comparative and interpretive analyses of the measurements and predictions. A second, no less important, objective was to try out, in a full-scale field setting, the various instruments and equipment to be employed in the future on a much larger, more complex, thermal test of longer duration, such as the Drift Scale Test. This ''shake down'' or trial aspect of the Single Heater Test applied

Assessment of a Hybrid Retrofit Gas Water Heater

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, Marc [Davis Energy Group, Davis, CA (United States); Weitzel, Elizabeth [Davis Energy Group, Davis, CA (United States); Backman, Christine [Davis Energy Group, Davis, CA (United States)

2017-02-28

This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

Assessment of a Hybrid Retrofit Gas Water Heater

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

2017-02-01

This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

Feedwater heater performance evaluation using the heat exchanger workstation

International Nuclear Information System (INIS)

Ranganathan, K.M.; Singh, G.P.; Tsou, J.L.

1995-01-01

A Heat Exchanger Workstation (HEW) has been developed to monitor the condition of heat exchanging equipment power plants. HEW enables engineers to analyze thermal performance and failure events for power plant feedwater heaters. The software provides tools for heat balance calculation and performance analysis. It also contains an expert system that enables performance enhancement. The Operation and Maintenance (O ampersand M) reference module on CD-ROM for HEW will be available by the end of 1995. Future developments of HEW would result in Condenser Expert System (CONES) and Balance of Plant Expert System (BOPES). HEW consists of five tightly integrated applications: A Database system for heat exchanger data storage, a Diagrammer system for creating plant heat exchanger schematics and data display, a Performance Analyst system for analyzing and predicting heat exchanger performance, a Performance Advisor expert system for expertise on improving heat exchanger performance and a Water Calculator system for computing properties of steam and water. In this paper an analysis of a feedwater heater which has been off-line is used to demonstrate how HEW can analyze the performance of the feedwater heater train and provide an economic justification for either replacing or repairing the feedwater heater

Welding shield for coupling heaters

Science.gov (United States)

Menotti, James Louis

2010-03-09

Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

40 CFR 63.7491 - Are any boilers or process heaters not subject to this subpart?

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Are any boilers or process heaters not..., and Institutional Boilers and Process Heaters What This Subpart Covers § 63.7491 Are any boilers or process heaters not subject to this subpart? The types of boilers and process heaters listed in paragraphs...

Numerical analysis of flow in a solar heater of air packing with shavings; Analisis numerico del flujo en un calentador solar de aire empacado con viruta

Energy Technology Data Exchange (ETDEWEB)

Lopez C, Raymundo; Morales G, Juan R; Diaz C, Alen; Lara V, Araceli; Lizardi R, Arturo [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D.F. (Mexico); Vaca M, Mabel [UNAM, Mexico, D.F. (Mexico)

2000-07-01

The temperature distribution of air through a solar heater is determined by means of the equations of heat, mass, momentum, and energy conservation. The solution is obtained by means of the numeric model of finite volume, using the CFC2000 software, V. 3.3. The studied flow is laminar. The temperature distribution resulted quite similar for different Reynolds numbers; the greatest difference was less than 4 Celsius degrees, for similar ranges of solar radiation. The influence of the separation that exists between the clear cover and the free surface of the material used as thermal summit (b) was analyzed. A difference up to 41 Celsius degrees for a Reynolds number of 1000 and values of b between 3 and 7 cm. For a Reynolds of 2000, the difference was of 29 Celsius degrees, in the same range of b. [Spanish] Se determinan la distribucion de temperaturas del aire, a lo largo de un calentador solar, aplicando las ecuaciones de conservacion de masa, cantidad de movimiento y energia. La solucion se obtiene con el modelo numerico de volumen finito y la utilizacion del programa de computadora llamado CFC2000 version 3.3. El flujo estudiado es del tipo laminar. La distribucion de temperaturas resulto ser muy semejante para diferentes valores del numero de Reynolds, la diferencia mayor resulto menor a 4 grados Celsius, para rangos similares de radiacion solar. Se analizo la influencia de la separacion que existe entre la cubierta transparente y la superficie libre del material que sirve como almacen termico (b). Se encontro una diferencia maxima de hasta 41 grados celsius para un numero de Reynolds de 1000 y los valores de b entre 3 y 7 cm. Cuando el Reynolds fue de 2000 la diferencia fue de 29 grados Celsius, en el mismo rango de b.

Development and Validation of a Gas-Fired Residential Heat Pump Water Heater - Final Report

Energy Technology Data Exchange (ETDEWEB)

Michael Garrabrant; Roger Stout; Paul Glanville; Janice Fitzgerald; Chris Keinath

2013-01-21

For gas-fired residential water heating, the U.S. and Canada is predominantly supplied by minimum efficiency storage water heaters with Energy Factors (EF) in the range of 0.59 to 0.62. Higher efficiency and higher cost ($700 - $2,000) options serve about 15% of the market, but still have EFs below 1.0, ranging from 0.65 to 0.95. To develop a new class of water heating products that exceeds the traditional limit of thermal efficiency, the project team designed and demonstrated a packaged water heater driven by a gas-fired ammonia-water absorption heat pump. This gas-fired heat pump water heater can achieve EFs of 1.3 or higher, at a consumer cost of $2,000 or less. Led by Stone Mountain Technologies Inc. (SMTI), with support from A.O. Smith, the Gas Technology Institute (GTI), and Georgia Tech, the cross-functional team completed research and development tasks including cycle modeling, breadboard evaluation of two cycles and two heat exchanger classes, heat pump/storage tank integration, compact solution pump development, combustion system specification, and evaluation of packaged prototype GHPWHs. The heat pump system extracts low grade heat from the ambient air and produces high grade heat suitable for heating water in a storage tank for domestic use. Product features that include conventional installation practices, standard footprint and reasonable economic payback, position the technology to gain significant market penetration, resulting in a large reduction of energy use and greenhouse gas emissions from domestic hot water production.

ITER L 6 equatorial maintenance duct remote handling study

International Nuclear Information System (INIS)

Millard, J.

1996-09-01

The status and conclusions of a preliminary study of equatorial maintenance duct remote handling is reported. Due to issues with the original duct design a significant portion of the study had to be refocused on equatorial duct layout studies. The study gives an overview of some of the options for design of these ducts and the impact of the design on the equipment to work in the duct. To develop a remote handling concept for creating access through the ducts the following design tasks should be performed: define the operations sequences for equatorial maintenance duct opening and closing; review the remote handling requirements for equatorial maintenance duct opening and closing; design concept for door and pipe handling equipment and to propose preliminary procedures for material handling outsides the duct. 35 figs

Spectral measurements of gamma radiation streaming through ducts

International Nuclear Information System (INIS)

Meenakshisundaram, P.K.; Bhatnagar, V.M.; Raghunath, V.M.; Gopinath, D.V.

1979-01-01

The paper presents the spectral measurements of gamma radiation streaming through multi-legged rectangular concrete ducts for cesium-137 and cobald-60 sources. Effect of lead lining the inner surface of the duct on the streaming radiation spectrum and optimization of liner thickness for minimum streaming radiation dose have been studied. For three-legged ducts, a comparative analysis of lead lining the entire duct as against lining any one or both the corners of the duct is reported. It is seen that lead lining any one of the corners would reduce the streaming radiation dose by a factor of 5 to 12. Lining both the corners which is nearly as effective as lining the entire duct reduces the dose by a factor of 16 to 60 depending on the soruce energy and duct dimensions. (orig.)

Finite element analyses of a heater-interruption in the HAW test field

International Nuclear Information System (INIS)

Horn, B.A. van den.

1991-09-01

In this report the results of two finite element analyses of the HAW field are presented. The determination of the influence of a heater-interruption on the tube load as well as the differences in the evaluation of the tube load for both types of boreholes (type A and type B) are the main objectives of this report. Axisymmetric models are made for both type of boreholes in order to simulate this heater-interruption. It appeared that a heater-interruption of 4 hours leads to a temperature drop of 17.2deg C at the borehole wall and to a maximum reduction of the tube load of 1.76 MPa. About 20 days after reparation of the heaters of the heaters the evolution of the maximum temperature and the maximum tube load will be rehabilitated; the difference with the corresponding evolutions due to an uninterrupted heat-production are negligible. (author). 9 refs.; 25 figs.; 5 tabs

Effects of bending-torsional duct-induced swirl distortion on aerodynamic performance of a centrifugal compressor

Science.gov (United States)

Hou, Hongjuan; Wang, Leilei; Wang, Rui; Yang, Yanzhao

2017-04-01

A turbocharger compressor working in commercial vehicles, especially in some passenger cars, often works together with some pipes with complicated geometry as an air intake system, due to limit of available space in internal combustion engine compartments. These pipes may generate various distortions of physical parameters of the air at the inlet of the compressor and therefore the compressor aerodynamic performance deteriorates. Sometimes, the turbocharging engine fails to work at some operation points. This paper investigates the effects of various swirl distortions induced by different bending-torsional intake ducts on the aerodynamic performance of a turbocharger compressor by both 3D numerical simulations and experimental measurements. It was found that at the outlet of the pipes the different inlet ducts can generate different swirl distortions, twin vortices and bulk-like vortices with different rotating directions. Among them, the bulk-like vortices not only affect seriously the pressure distribution in the impeller domain, but also significantly deteriorate the compressor performance, especially at high flow rate region. And the rotating direction of the bulk-like vortices is also closely associated with the efficiency penalty. Besides the efficiency, the transient flow rate through a single impeller channel, or the asymmetric mass flow crossing the whole impeller, can be influenced by two disturbances. One is from the upstream bending-torsional ducts; other one is from the downstream volute.

Experimental investigation of a Hybrid Solar Drier and Water Heater System

International Nuclear Information System (INIS)

Mohajer, Alireza; Nematollahi, Omid; Joybari, Mahmood Mastani; Hashemi, Seyed Ahmad; Assari, Mohammad Reza

2013-01-01

Highlights: • A Hybrid Solar Drier and Water Heater System experimentally investigated. • Using collected data, GIS maps were plotted for solar energy of Khuzestan Province. • System is presented which facilitates a dual-purpose solar collector. • The system includes a 100 l water storage tank, a solar dryer with 5 trays. • Experiments were carried out to dry vegetables (parsley, dill and coriander). - Abstract: Drying process is of great importance in food industries. One of the best methods of food drying is using solar dryers. For initial estimation of solar energy, calculations were made for statistical information measured by Renewable Energy Organization of Iran. Using collected data, GIS maps were plotted for solar energy of Khuzestan Province, Iran. In this study, a new hybrid system is presented which facilitates a dual-purpose solar collector to simultaneously support a dryer system and provide consumptive hot water. The system includes a 100 l water storage tank, a solar dryer with 5 trays, and a dual-purpose collector. Experiments were carried out to dry a mixture of vegetables (parsley, dill and coriander) at constant air and water flow rates. Besides, an electrical heater has been used as an auxiliary source for heating. The results indicated that the system optimally dried the vegetables and simultaneously provided the consumptive hot water

Financial Aspects of Bile Duct Injuries.

Science.gov (United States)

Palaz Alı, Ozgkıour; Ibis, Abdil Cem; Gurtekin, Basak

2017-11-04

BACKGROUND Major bile duct injury is the most worrisome complication of cholecystectomy. There is no detailed data about the incidence or treatment-related costs of bile duct injuries in Turkey. We aimed to determine prevalence and therapeutic costs of patients with major biliary duct injuries managed in our department, and further estimate a projection of these parameters at the national level. MATERIAL AND METHODS All patients admitted due to bile duct injury during cholecystectomy from 2011 to 2014 were included. Healthcare costs were calculated by summing of their all treatment-related costs in Istanbul Medical Faculty. We collected 2014-2015 data on number of patients diagnosed with cholecystitis in Turkey, the number of cholecystectomies, and the number of the interventions performed following these initial surgeries, which were obtained from the Turkish Social Security Institution. RESULTS Forty-nine patients were enrolled and bilioenteric diversion was performed in 39 patients: 20.4% of patients had Bismuth II, 38.8% had Bismuth III, and 40.8% had Bismuth IV biliary stricture. Comparison of stricture types with total costs, days of hospitalization, and outpatient clinic costs revealed significant differences. Mean total cost of corrective surgeries was 9199 TRY. We estimated that 1.5% to 2.4% of patients who underwent cholecystectomy in Turkey have bile duct injury (including 0.3% with major bile duct injury). CONCLUSIONS New preventive strategies should be used to avoid bile duct injuries, which have a huge financial impact on the national economy.

Vitellointestinal Duct Anomalies in Infancy.

Science.gov (United States)

Kadian, Yogender Singh; Verma, Anjali; Rattan, Kamal Nain; Kajal, Pardeep

2016-01-01

Vitellointestinal duct (VID) or omphalomesenteric duct anomalies are secondary to the persistence of the embryonic vitelline duct, which normally obliterates by weeks 5-9 of intrauterine life. This is a retrospective analysis of a total of 16 patients of symptomatic remnants of vitellointestinal duct from period of Jan 2009 to May 2013. Male to female ratio (M:F) was 4.3:1 and mean age of presentation was 2 months and their mode of presentation was: patent VID in 9 (56.25%) patients, umbilical cyst in 2(12.25%), umbilical granuloma in 2 (12.25%), and Meckel diverticulum as content of hernia sac in obstructed umbilical hernia in 1 (6.25%) patient. Two patients with umbilical fistula had severe electrolyte disturbance and died without surgical intervention. Persistent VID may have varied presentations in infancy. High output umbilical fistula and excessive bowel prolapse demand urgent surgical intervention to avoid morbidity and mortality.

An Integrated Heavy Fuel Piston Engine Ducted Fan Propulsion Unit for Personal Air Vehicles, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The proposed PAVE propulsion system technology demonstration combines an innovative high-speed aero-diesel engine with a novel ducted fan assembly resulting in a low...

An Integrated Heavy Fuel Piston Engine Ducted Fan Propulsion Unit for Personal Air Vehicles, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed PAVE propulsion system technology demonstration combines an innovative high-speed aero-diesel engine with a novel ducted fan assembly resulting in a low...

Cholangiographic evaluation of bile duct carcinoma

International Nuclear Information System (INIS)

Nichols, D.A.; MacCarty, R.L.; Gaffey, T.A.

1983-01-01

Cholangiograms and clinical histories of 82 patients with biopsy-proved bile duct carcinoma were reviewed. The carcinomas were classified according to morphologic findings and clinical outcome. Ulcerative colitis and antecedent inflammatory disease of the biliary tree, particularly primary sclerosing cholangitis, seem to predispose to the development of bile duct carcinoma. Focal stenotic lesions were the most common morphologic type (62/82). Polypoid carcinomas and diffuse sclerosing carcinomas were less common and of about equal frequency. Prognosis was best for patients with polypoid carcinomas and worst for those with diffuse sclerosing carcinomas. In 69 cases (84%), the tumors involved the intrahepatic or proximal extrahepatic ducts, makin curative resection difficult or impossible. Patients with carcinomas limited to the more distal extrahepatic bile ducts had a longer average survival and a higher probability of surgical cure. Proper management of patients with bile duct carcinoma requires a complete and accurate cholangiographic evaluation of the morphology, location, and extent of the disease

Characteristics of indoor radon and its progeny in a Japanese dwelling while using air appliances

International Nuclear Information System (INIS)

Pornnumpa, C.; Tokonami, S.; Sorimachi, A.; Kranrod, C.

2015-01-01

Characteristics of radon and its progeny were investigated in different air conditions by turning four types of indoor air appliances on and off in a two-story concrete Japanese dwelling. The four appliances were air conditioner, air cleaner, gas heater and cooker hood. The measurements were done using two devices: (1) a Si-based semiconductor detector for continuous measurement of indoor radon concentration and (2) a ZnS(Ag) scintillation counting system for equilibrium-equivalent radon concentration. Throughout the entire experiment, the cooker hood was the most effective in decreasing indoor radon concentration over a long period of time and the less effective was the air conditioner, while the air cleaner and gas heater did not affect the concentration of radon. However, the results measured in each air condition will differ according to the lifestyles and activities of the inhabitants. In this study, indoor radon and its progeny in a Japanese dwelling will be characterised by the different air conditions. (authors)

Theoretical temperature fields for the Stripa heater project. Vol. 1

International Nuclear Information System (INIS)

Chan, T.; Cook, N.G.W.; Tsang, C.F.

1978-09-01

The report concerns thermal conduction calculations for the three in-situ heater experiments at Stripa which constitute part of the Swedish-American Cooperative Program on Radioactive Waste Storage in Mined Caverns. A semianalytic solution based on the Green's function method has been developed for an array of arbitrary time-dependent finite line heaters in a semi-infinite medium. This method as well as a three dimensional numerical model using IFD (Integrated Finite Difference) technique has been applied to model the field situations at Stripa. Comparison has demonstrated that the finite line source solution for the rock temperature is in excellent agreement with the numerical model solution as well as with a closed form finite cylinder source solution. It was found that maximum temperature rise in the rock within the two year experiment period will be 178 0 C for the 3.6 kW full-scale heater experiment, 345 0 C for the full-scale experiment with a 5 kW central heater and eight 0.72 kW peripheral heaters, and less than 200 0 C for the time-scaled experiment. The ring of eight peripheral heaters in the second full-scale experiment will provide a nominally uniform temperature rise within its perimeter a few weeks after turn-on. The high temperature zone is localized throughout the duration of all three experiments. Nevertheless, the effect of different spacings on the thermal interaction between adjacent radioactive waste canisters will be demonstrated by the time-scaled experiment. Detailed results are presented in the form of tables, temperature profiles and contour plots. Predicted temperatures have been stored in an on-site computer for real-time comparison with field data. 56 figures, 7 tables

Hazardous air pollutant emissions from gas-fired combustion sources: emissions and the effects of design and fuel type

Energy Technology Data Exchange (ETDEWEB)

England, G.C.; McGrath, T.P. [GE-Energy and Environmental Research Corp., Irvine, CA (United States); Gilmer, L. [Equilon Enterprises, Bellaire, TX (United States); Seebold, J.G. [Chevron Research and Technology Co., Richmond, CA (United States); Lev-On, M. [ARCO, Los Angeles, CA (United States); Hunt, T. [American Petroleum Institute, Washington, DC (United States)

2001-07-01

Air emissions from gas-fired combustion devices such as boilers, process heaters, gas turbines and stationary reciprocating engines contain hazardous air pollutants (HAPs) subjected to consideration under the federal clean air act (CAA). This work presents a recently completed major research project to develop an understanding of HAP emissions from gas-fired boilers and process heaters and new HAP emission factors based on field emission tests of gas-fired external combustion devices used in the petroleum industry. The effect of combustion system design and operating parameters on HAP emissions determined by both field and research tests are discussed. Data from field tests of gas-fired petroleum industry boilers and heaters generally show very low emission levels of organic HAPs. A comparison of the emission data for boilers and process heaters, including units with and without various forms of NO{sub x} emission controls, showed no significant difference in organic HAP emission characteristics due to process or burner design. This conclusion is also supported by the results of research tests with different burner designs. Based on field tests of units fired with natural gas and various petroleum industry process gases and research tests in which gas composition was intentionally varied, organic HAP emissions were not determined to be significantly affected by the gas composition. Research data indicate that elevated organic HAP emission levels are found only under extreme operating conditions (starved air or high excess air combustion) associated with poor combustion. (author)

Hazardous air pollutant emissions from gas-fired combustion sources: emissions and the effects of design and fuel type

International Nuclear Information System (INIS)

England, G.C.; McGrath, T.P.; Gilmer, L.; Seebold, J.G.; Lev-On, M.; Hunt, T.

2001-01-01

Air emissions from gas-fired combustion devices such as boilers, process heaters, gas turbines and stationary reciprocating engines contain hazardous air pollutants (HAPs) subjected to consideration under the federal clean air act (CAA). This work presents a recently completed major research project to develop an understanding of HAP emissions from gas-fired boilers and process heaters and new HAP emission factors based on field emission tests of gas-fired external combustion devices used in the petroleum industry. The effect of combustion system design and operating parameters on HAP emissions determined by both field and research tests are discussed. Data from field tests of gas-fired petroleum industry boilers and heaters generally show very low emission levels of organic HAPs. A comparison of the emission data for boilers and process heaters, including units with and without various forms of NO x emission controls, showed no significant difference in organic HAP emission characteristics due to process or burner design. This conclusion is also supported by the results of research tests with different burner designs. Based on field tests of units fired with natural gas and various petroleum industry process gases and research tests in which gas composition was intentionally varied, organic HAP emissions were not determined to be significantly affected by the gas composition. Research data indicate that elevated organic HAP emission levels are found only under extreme operating conditions (starved air or high excess air combustion) associated with poor combustion. (author)

Borehole heater test at KAERI Underground Research Tunnel

International Nuclear Information System (INIS)

Kwon, S. K.; Cho, W. J.; Jeon, S. W.

2009-09-01

At HLW repository, the temperature change due to the decay heat in near field can affect the hydraulic, mechanical, and chemical behaviors and influence on the repository safety. Therefore, the understanding of the thermal behavior in near field is essential for the site selection, design, as well as operation of the repository. In this study, various studies for the in situ heater test, which is for the investigation of the thermo-mechanical behavior in rock mass, were carried out. At first, similar in situ tests at foreign URLs were reviewed and summarized the major conclusions from the tests. After then an adequate design of heater, observation sensors, and data logging system were developed and installed with a consideration of the site condition and test purposes. In order to minimize the effect of hydraulic phenomenon, a relatively day zone was chosen for the in situ test. Joint distribution and characteristics in the zone were surveyed and the rock mass properties were determined with various laboratory tests. In this study, an adequate location for an in situ borehole heater test was chosen. Also a heater for the test was designed and manufactured and the sensors for measuring the rock behavior were installed. It was possible to observe that stiff joints are developed overwhelmingly in the test area from the joint survey at the tunnel wall. The major rock and rock mass properties at the test site could be determined from the thermo-mechanical laboratory tests using the rock cores retrieved from the site. The measured data were implemented in the three-dimensional computer simulation. From the modeling using FLAC3D code, it was possible to find that the heat convection through the tunnel wall can influence on temperature distribution in rock. Because of that it was necessary to installed a blocking wall to minimize the effect of ventilation system on the heater test, which is carrying out nearby the tunnel wall. The in situ borehole heater test is the first

New concept of the buildup factor in bent ducts

International Nuclear Information System (INIS)

Faik Ouahab, Z.; Jehouani, A.; Groetz, J.-E.

2011-01-01

A major problem confronting the radiation shielding designer is the accurate determination of neutron streaming through various penetrations in walls, ducts and mazes. The previous studies on neutron transmission were performed through empty ducts. The aim of this work is to evaluate the neutron transmission probability through a filled bent duct and the proposition of a new concept of the buildup factor for neutrons in multilegged ducts. An angular biaising technique is used in the Monte Carlo simulations to accelerate the calculation convergence. Results are first compared with those obtained by the MCNPX code. For an empty bent duct, the neutron transmission is only due to the neutron reflection on the duct wall. For a filled duct, the major contribution is due to the scattering on the atoms filling the duct.

Molecular Mechanisms of Bile Duct Development

OpenAIRE

Zong, Yiwei; Stanger, Ben Z.

2010-01-01

The mammalian biliary system, consisting of the intrahepatic and extrahepatic bile ducts, is responsible for transporting bile from the liver to the intestine. Bile duct dysfunction, as is seen in some congenital biliary diseases such as Alagille syndrome and biliary atresia, can lead to the accumulation of bile in the liver, preventing the excretion of detoxification products and ultimately leading to liver damage. Bile duct formation requires coordinated cell-cell interactions, resulting in...

Design and performance of low-wattage electrical heater probe

International Nuclear Information System (INIS)

Biddle, R.; Wetzel, J.R.; Cech, R.

1997-01-01

A mound electrical calibration heater (MECH) has been used in several EG and G Mound developed calorimeters as a calibration tool. They are very useful over the wattage range of a few to 500 W. At the lower end of the range, a bias develops between the MECH probe and calibrated heat standards. A low-wattage electrical calibration heater (L WECH) probe is being developed by the Safeguards Science and Technology group (NIS-5) of Los Alamos National Laboratory based upon a concept proposed by EG and G Mound personnel. The probe combines electrical resistive heating and laser-light powered heating. The LWECH probe is being developed for use with power settings up to 2W. The electrical heater will be used at the high end of the range, and laser-light power will be used low end of the wattage range. The system consists of two components: the heater probe and a control unit. The probe is inserted into the measuring cavity through an opening in the insulating baffle, and a sleeve is required to adapt to the measuring chamber. The probe is powered and controlled using electronics modules located separately. This paper will report on the design of the LWECH probe, initial tests, and expected performance

Unilateral Duplication Of Parotid Duct. A Rare Anatomical Variation

Directory of Open Access Journals (Sweden)

Humberto Ferreira Arquez

2017-11-01

Full Text Available Background: The paired parotid glands are the largest of the major salivary glands and produces mainly serous secretions. The secretion of this gland reaches the oral cavity through single parotid duct (Stensen’s duct. The parotid duct begins at the anterior border of the gland, crosses the masseter muscle, and then pierces the buccinator muscle to reach the mucosa lining the mouth at the level of the cheek. The purpose of this study is determine the morphologic features of the parotid duct and describe an anatomical variation until now unreported. Methods and Findings: A total of 17 cadavers were used for this study in the Morphology Laboratory at the University of Pamplona. In a cadaver were findings: The main parotid duct originated two conducts: Left superior parotid duct and Left inferior parotid duct, is observed the criss-cross of the ducts, and then perforated the buccinator muscle and entered the oral cavity at a double parotid papilla containing a double opening, separated from each other in 0,98 mm. In the remaining  33 parotid regions (97.06% the parotid duct is conformed to the classical descriptions given in anatomical textbooks. Conclusions: The parotid duct anatomy is important for duct endoscopy, lithotripsy, sialography and trans-ductal facial nerve stimulation in the early stage of facial palsy in some cases. The anatomical variations also has clinical importance for parotid gland surgery and facial cosmetic surgery. To keep in mind the parotid duct variation will reduce iatrogenic injury risks and improve diagnosis of parotid duct injury.

Thoracic duct lymphography by subcutaneous contrast agent ...

African Journals Online (AJOL)

A second lymphography revealed a collateral thoracic duct that was not detected during the first lymphography. The collateral duct was ligated and chylothorax was resolved after the second surgery. The lymphography applied in this study was minimally-invasive and easily provided images of the thoracic duct in a dog with ...

Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

Science.gov (United States)

Toffoli, Valeria; Carrato, Sergio; Lee, Dongkyu; Jeon, Sangmin; Lazzarino, Marco

2013-01-01

The design and characteristics of a micro-system for thermogravimetric analysis (TGA) in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using milli-Q water and polyurethane microcapsule. The results demonstrated that our approach provides a faster and more sensitive TGA with respect to commercial systems.

Air quality inside the passenger compartment of a bus.

Science.gov (United States)

Conceição, E Z; Silva, M C; Viegas, D X

1997-01-01

The indoor air quality in the passenger compartment of an intercity bus is studied. A system used for the remotion of the contaminants from the compartment, based on an extraction duct, was projected using a simple, unidimensional flow model with capability to predict the air exchange rate as a function of the vehicle velocity. Some tests using tracer gan methods were performed in a real vehicle with the contaminant remotion system mounted, in order to validate the calculation model and evaluate the performances of the system. A good agreement between the predicted and the experimental results was verified and the obtained air exchange rate was quite reasonable when compared with the former situation, without extraction duct.

Performance Analysis of a Solar Dryer Equipped with a Recycling Air System and Desiccant Chamber

Directory of Open Access Journals (Sweden)

M.H Aghkhani

2013-09-01

Full Text Available Drying is a high energy consuming process. Solar drying is one of the most popular methods for dehydration of agricultural products. In the present study, the performance of a forced convection solar dryer equipped with recycling air system and desiccant chamber was investigated. The solar dryer is comprised of solar collector, drying chamber, silica jell desiccant chamber, air ducts, fan and measuring and controlling system. Drying rate and energy consumption in three levels of air temperature (40, 45 and 50 oC and two modes of drying (with recycling air and no-recycling with open duct system were measured and compared. The results showed that increasing the drying air temperature decreased the drying time and increased the energy consumption in the mode of non-recycling air system. The dryer efficiency and drying rate were better in the mode of recycling air system than open duct system. The highest dryer efficiency was obtained from drying air temperature of 50 oC and the mode of recycling air system. In general, the efficiency of solar collector and the highest efficiency of the dryer were 0.34 and 0.41, respectively.

Stretchable Tattoo-Like Heater with On-Site Temperature Feedback Control

Directory of Open Access Journals (Sweden)

Andrew Stier

2018-04-01

Full Text Available Wearable tissue heaters can play many important roles in the medical field. They may be used for heat therapy, perioperative warming and controlled transdermal drug delivery, among other applications. State-of-the-art heaters are too bulky, rigid, or difficult to control to be able to maintain long-term wearability and safety. Recently, there has been progress in the development of stretchable heaters that may be attached directly to the skin surface, but they often use expensive materials or processes and take significant time to fabricate. Moreover, they lack continuously active, on-site, unobstructive temperature feedback control, which is critical for accommodating the dynamic temperatures required for most medical applications. We have developed, fabricated and tested a cost-effective, large area, ultra-thin and ultra-soft tattoo-like heater that has autonomous proportional-integral-derivative (PID temperature control. The device comprises a stretchable aluminum heater and a stretchable gold resistance temperature detector (RTD on a soft medical tape as fabricated using the cost and time effective “cut-and-paste” method. It can be noninvasively laminated onto human skin and can follow skin deformation during flexure without imposing any constraint. We demonstrate the device’s ability to maintain a target temperature typical of medical uses over extended durations of time and to accurately adjust to a new set point in process. The cost of the device is low enough to justify disposable use.

Cystic Duct Closure by Sealing With Bipolar Electrocoagulation

Science.gov (United States)

Damgaard, B.; Jorgensen, L. N.; Larsen, S. S.; Kristiansen, V. B.

2010-01-01

Background: Cystic duct leakage after cholecystectomy is not uncommon and is a potentially serious complication. The aim of this study was to assess a bipolar sealing system (LigaSure®) for closure of the cystic duct. Methods: The records from consecutive laparoscopic cholecystectomies performed in 2 hospitals with closure of the cystic duct with LigaSure after informed consent were recorded and complications and morbidity registered. The records were compared with those of patients undergoing laparoscopic cholecystectomy with closure of the cystic duct with clips during the same period. Results: During the study period, 218 laparoscopic cholecystectomies were performed; 102 of these were performed with the LigaSure. One patient was excluded due to violation of the protocol. We experienced no cases of cystic duct leakage, but in one patient, bile leakage from the gallbladder bed was observed probably due to a small aberrant duct. Conclusion: The LigaSure system was safe and effective for closure and division of the cystic duct in laparoscopic cholecystectomy. PMID:20412641