WorldWideScience

Sample records for air heater duct

  1. Experimental and simulation studies on a single pass, double duct solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Forson, F.K. [Kwame Nkrumah Univ. of Science and Technology, Dept. of Mechanical Engineering, Kumasi (Ghana); Rajakaruna, H. [De Montfort Univ., School of Engineering and Technology, Leicester (United Kingdom)

    2003-05-01

    A mathematical model of a single pass, double duct solar air heater (SPDDSAH) is described. The model provides a design tool capable of predicting: incident solar radiation, heat transfer coefficients, mean air flow rates, mean air temperature and relative humidity at the exit. Results from the simulation are presented and compared with experimental ones obtained on a full scale air heater and a small scale laboratory one. Reasonable agreement between the predicted and measured values is demonstrated. Predicted results from a parametric study are also presented. It is shown that significant improvement in the SPDDSAH performance can be obtained with an appropriate choice of the collector parameters and the top to bottom channel depth ratio of the two ducts. The air mass flow rate is shown to be the dominant factor in determining the overall efficiency of the heater. (Author)

  2. Heat Transfer Enhancement in Solar Air Heater Duct Fitted With Punched Hole Delta Winglets

    Science.gov (United States)

    Warrier, Hithesh. U.; Kotebavi, Vinod. M.

    2016-09-01

    This paper investigates the thermal performance of solar air heater fitted with delta winglet type vortex generators with holes punched on it by experimental and numerical analysis. Delta winglet type vortex generators having holes punched onto it are fitted in a duct of size 400*300*30mm.it is placed in duct in 3 different configurations, as an array having 5 pair in one row. Delta winglet pair has an attack angle of 30degree, with height of winglet equal to half of duct height. The study is done for Reynolds's no in the range of 9000 to 25000. Thermal performance is evaluated by analyzing both friction factor and Nussult's number using Webb's correlation for surface roughness. Numerical simulation is done using Ansys fluent. Experimental and numerical results are then compared. Results shows that heat transfer enhancement of about 20-150% can be achieved by using punched hole delta winglet.

  3. Performance Analysis of a Shallow Duct Flat Plate Solar Air Heater with and without Porous Media

    Directory of Open Access Journals (Sweden)

    Haroun A.K. Shahad

    2016-12-01

    Full Text Available In this study a flat plate solar air heater with a shallow duct is analyzed experimentally. The collector consists of a 4.5m long air duct with a (20×5cm cross-sectional area. The air duct consists of four channels so that the collector becomes more compact. The collector is studied under the weather conditions of Hilla city – Iraq with latitude and longitude equal 32.3° N and 44.25° E respectively and it is tilted by 45° with the horizontal plane. The effect of the air mass flow rate on the collector performance is also studied.The performance of the collector is analyzed with and without porous media stuffing. The measured parameters are the air and absorber temperatures, air speed and pressure drop. The temperatures are measured by means of type (K thermocouples as this type covers the temperature range of the studied system. The values of the temperature are displayed by temperature data logger devices. The air speed and pressure drop are measured by digital anemometer and manometer devices respectively. The results of the studied system show that as the air mass flow rate increases, the temperature of both the flowing air and the absorber decrease, whilst the efficiency of the collector increases. The results also show that the addition of the steel wool porous material inside the air duct increases the temperature of both the flowing air and the absorber, and by that increases the efficiency of the collector. The porous media also caused an increase in the pressure drop between the outlet air and the atmosphere. This pressure drop increased with the increase in the air mass flow rate

  4. Heat transfer and friction correlations for artificially roughened solar air heater duct with discrete W-shaped ribs

    International Nuclear Information System (INIS)

    Kumar, Arvind; Bhagoria, J.L.; Sarviya, R.M.

    2009-01-01

    An experimental investigation has been carried out to study the heat transfer and friction characteristics in solar air heater by using discrete W-shaped roughness on one broad wall of solar air heater with an aspect ratio of 8:1, the roughened wall being heated while the remaining three walls are insulated. The experiment encompassed Reynolds number (Re) range from 3000 to 15,000, relative roughness height (e/D h ) in the range of 0.0168-0.0338, relative roughness pitch (p/e) 10 and the angle of attack (α) in the range of 30-75 deg. The effect of parameters on the heat transfer and friction are compared with the result of smooth duct under similar flow conditions. Correlations for heat transfer and friction have been developed as a function of roughness and flow parameters.

  5. Heat Transfer Enhancement in a Solar Air Heater with Roughened Duct Having Arc-Shaped Elements as Roughness Element on the Absorber Plate

    Science.gov (United States)

    Singh, Anil Prakash; Goel, Varun; Vashishtha, Siddhartha; Kumar, Amit

    2016-07-01

    An experimental study has been carried out for the heat transfer and friction characteristics for arc shaped roughness element used in solar air heaters. Duct has an aspect ratio (W/H) of 11, relative roughness pitch (p/e) range of 4-16, relative roughness height (e/D) range of 0.027-0.045, Reynolds number ( Re) range of 2200-22,000 and arc angle (α) was kept constant at 60°. The effects of Re, relative roughness pitch (p/e) and relative roughness height (e/D) on heat transfer and friction factor have been discussed. The results obtained for Nusselt number and friction factor has been compared with smooth solar air heater to see the enhancement in heat transfer and friction factor and it is found out that considerable enhancement takes place in case of heat transfer as well as in friction factor. Correlations were also developed for Nusselt number and friction factor. Thermo-hydraulic performance parameter is also calculated for the same.

  6. Regenerative air heater

    Science.gov (United States)

    Hasselquist, Paul B.; Baldner, Richard

    1982-01-01

    A gas-cooled steel skirt is used to support a refractory cored brick matrix and dome structure in a high temperature regenerative air heater useful in magnetohydrodynamic power generation. The steel skirt thermally expands to accommodate the thermal expansion of the dome structure despite substantial temperature differential thereby reducing relative movement between the dome bricks. Gas cooling of the steel skirt allows the structure to operate above its normal temperature during clean-out cycles and also allows for the control of the thermal expansion of the steel skirt.

  7. Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, M. L. [Southface Energy Inst., Atlanta, GA (United States); Francisco, A. [Southface Energy Inst., Atlanta, GA (United States); Roberts, S. G. [Southface Energy Inst., Atlanta, GA (United States)

    2016-05-01

    The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas.

  8. Low cost solar air heater

    International Nuclear Information System (INIS)

    Gill, R.S.; Singh, Sukhmeet; Singh, Parm Pal

    2012-01-01

    Highlights: ► Single glazed low cost solar air heater is more efficient during summer while double glazed is better in winter. ► For the same initial investment, low cost solar air heaters collect more energy than packed bed solar air heater. ► During off season low cost solar air heater can be stored inside as it is light in weight. - Abstract: Two low cost solar air heaters viz. single glazed and double glazed were designed, fabricated and tested. Thermocole, ultraviolet stabilised plastic sheet, etc. were used for fabrication to reduce the fabrication cost. These were tested simultaneously at no load and with load both in summer and winter seasons along with packed bed solar air heater using iron chips for absorption of radiation. The initial costs of single glazed and double glazed are 22.8% and 26.8% of the initial cost of packed bed solar air heater of the same aperture area. It was found that on a given day at no load, the maximum stagnation temperatures of single glazed and double glazed solar air heater were 43.5 °C and 62.5 °C respectively. The efficiencies of single glazed, double glazed and packed bed solar air heaters corresponding to flow rate of 0.02 m 3 /s-m 2 were 30.29%, 45.05% and 71.68% respectively in winter season. The collector efficiency factor, heat removal factor based on air outlet temperature and air inlet temperature for three solar air heaters were also determined.

  9. Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, M. L. [Southface Energy Inst., Upper Marlboro, MD (United States); Francisco, A.; Roberts, S. G.

    2016-05-01

    The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk of condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.

  10. Effect of circularity of perforation holes in V-shaped blockages on heat transfer and friction characteristics of rectangular solar air heater duct

    International Nuclear Information System (INIS)

    Alam, Tabish; Saini, R.P.; Saini, J.S.

    2014-01-01

    Highlights: • Effect of perforation shapes of blocks on heat transfer has been investigated. • A new parameter, circularity which represents perforation shape is proposed. • Effect of angle of attack of V-blocks on heat transfer has been investigated. • Nusselt number and friction factor correlations have been developed. - Abstract: The effect of non-circular perforation holes in term of circularity of V-shaped blockages attached to one heated wall of a rectangular duct of solar air heater. Five different hole shapes ranging from circular to square to rectangular in the circularity range of 1–0.6 have been used with varying relative pitch of 4–12, relative blockage height of 0.4–1.0, open area ratio of 5–25% and angle of attack of 30–75° and Reynolds number of flow was varied between 2000 and 20,000. It has been found that there exists an optimum non-circular shape of perforation holes that yields maximum value of Nusselt number; a perfectly circular hole performs substantially inferior as compared to a non-circular hole of considerable non-circularity (ψ = 0.69). An improvement of Nusselt number value in the ratio of 1.13 has been found when circular perforation holes are replaced by rectangular holes of circularity of 0.69. Correlations of Nusselt number as well of friction factor are established in term of Reynolds number and geometrical parameters of blockages which can be used to predict the values of Nusselt number and friction factor with considerably good accuracy

  11. Second law analysis of a solar air heater having 60° inclined ...

    African Journals Online (AJOL)

    Artificially roughened solar air heaters perform better than the smooth ones under the same operating conditions. However, artificial roughness leads to even more fluid pressure thereby increasing the pumping power. The entropy generation in the duct of solar air heater having 60° inclined discrete rib roughness on one ...

  12. Build Your Own Solar Air Heater.

    Science.gov (United States)

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    The solar air heater is a simple device for catching some of the sun's energy to heat a home. Procedures for making and installing such a heater are presented. Included is a materials list, including tools needed for constructing the heater, sources for obtaining further details, and a list of material specifications. (JN)

  13. 14 CFR 25.1103 - Induction system 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 system ducts and air duct systems....1103 Induction system ducts and air duct systems. (a) Each induction system duct upstream of the first... auxiliary power unit bleed air duct systems, no hazard may result if a duct failure occurs at any point...

  14. MHD air heater development technology. Report for the period October 1978-December 1978

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-04-01

    During the period covered by this report, work was done on all three tasks and is summarized as follows: Under Task 1 (design studies) the influence of heater system layout, duct dimensions, and heater sequencing on flow distribution was studied further. One result was that localizing the bulk of the pressure drop in the heaters tends to minimize heater-to-heater flow differences. The task of integrating the temperature and pressure solvers was pursued further. An analysis of current flow back up the air duct from the combustor was done. Results showed that the voltage gradient and power loss back up the air duct depend on the ratio of electrical conductivities of air and duct wall insulation. Under Task 2 (design support tests) Heat 201 was completed and much of the construction on the valve test rig was completed. Heat 201 was run with a Corhart X-317 (fusion cast magnesia-35% alumina, hereafter referred to as Corhart X-317 as this trade name designates not only composition, but microstructure, impurity level and manufacturer's process) matrix in the rig. Matrix Test 7 (Heat 201) ran for over four hundred hours but was terminated early because of a restriction in the bed. This was caused by failure of the insulating lining in the hot gas duct between the burner and the matrix. This liner of magnesia-chrome bricks (RFG) had been used in earlier tests. Reactions with seed/slag occurred and the resulting high viscosity slag partially plugged the bed. Under Task 3 (preliminary design of 5 MW heater) a topical report describing the design of the 5 MW test heater system was prepared. At the end of this reporting period it was being reviewed.

  15. Performance analysis of solar air heater with jet impingement on corrugated absorber plate

    Directory of Open Access Journals (Sweden)

    Alsanossi M. Aboghrara

    2017-09-01

    Full Text Available This paper deals with the experimental investigation outlet temperature and efficiency, of Solar Air heater (SAH. The experimental test set up designed and fabricated to study the effect of jet impingement on the corrugated absorber plate, through circular jets in a duct flow of solar air heater, and compared with conventional solar air heater on flat plat absorber. Under effect of mass flow rate (ṁ of air and solar radiation on outlet air temperature, and efficiency, are analyzed. Results show the flow jet impingement on corrugated plat absorber is a strong function of heat transfer enhancement. The present investigation concludes that the mass flow rate of air substantially influences the heat transfer on solar air heaters. And the thermal efficiency of proposed design duct is observed almost 14% more as compare to the smooth duct. At solar radiation 500–1000 (W/M2, 308 K ambient temperature and 0.01–0.03 (Kg/S mass flow rate

  16. 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....1103 Induction systems ducts and air duct systems. (a) Each induction system duct upstream of the first... it might cause a fire hazard. (b) Each duct must be strong enough to prevent induction system failure...

  17. Entropy generation and thermodynamic analysis of solar air heaters with artificial roughness on absorber plate

    Directory of Open Access Journals (Sweden)

    Prasad Radha K.

    2017-09-01

    Full Text Available This paper presents mathematical modelling and numerical analysis to evaluate entropy generation analysis (EGA by considering pressure drop and second law efficiency based on thermodynamics for forced convection heat transfer in rectangular duct of a solar air heater with wire as artificial roughness in the form of arc shape geometry on the absorber plate. The investigation includes evaluations of entropy generation, entropy generation number, Bejan number and irreversibilities of roughened as well as smooth absorber plate solar air heaters to compare the relative performances. Furthermore, effects of various roughness parameters and operating parameters on entropy generation have also been investigated. Entropy generation and irreversibilities (exergy destroyed has its minimum value at relative roughness height of 0.0422 and relative angle of attack of 0.33, which leads to the maximum exergetic efficiency. Entropy generation and exergy based analyses can be adopted for the evaluation of the overall performance of solar air heaters.

  18. Entropy generation and thermodynamic analysis of solar air heaters with artificial roughness on absorber plate

    Science.gov (United States)

    Prasad, Radha K.; Sahu, Mukesh K.

    2017-09-01

    This paper presents mathematical modelling and numerical analysis to evaluate entropy generation analysis (EGA) by considering pressure drop and second law efficiency based on thermodynamics for forced convection heat transfer in rectangular duct of a solar air heater with wire as artificial roughness in the form of arc shape geometry on the absorber plate. The investigation includes evaluations of entropy generation, entropy generation number, Bejan number and irreversibilities of roughened as well as smooth absorber plate solar air heaters to compare the relative performances. Furthermore, effects of various roughness parameters and operating parameters on entropy generation have also been investigated. Entropy generation and irreversibilities (exergy destroyed) has its minimum value at relative roughness height of 0.0422 and relative angle of attack of 0.33, which leads to the maximum exergetic efficiency. Entropy generation and exergy based analyses can be adopted for the evaluation of the overall performance of solar air heaters.

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

    African Journals Online (AJOL)

    DR OKE

    The present paper studies the thermal performance of solar air heater which is artificially roughened by providing multiple arcs with gap shaped roughness element. As thermal ..... Farina G, Performance analysis of solar air heaters of conventional design, Solar Energy, Vol. 41, No. 1, pp. 101-107. Bhagoria, J.L., Saini, J.S., ...

  20. Impact of kerosene space heaters on indoor air quality.

    Science.gov (United States)

    Hanoune, B; Carteret, M

    2015-09-01

    In recent years, the use of kerosene space heaters as additional or principal heat source has been increasing, because these heaters allow a continuous control on the energy cost. These devices are unvented, and all combustion products are released into the room where the heaters are operated. The indoor air quality of seven private homes using wick-type or electronic injection-type kerosene space heaters was investigated. Concentrations of CO, CO2, NOx, formaldehyde and particulate matter (0.02-10 μm) were measured, using time-resolved instruments when available. All heaters tested are significant sources of submicron particles, NOx and CO2. The average NO2 and CO2 concentrations are determined by the duration of use of the kerosene heaters. These results stress the need to regulate the use of unvented combustion appliances to decrease the exposure of people to air contaminants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Building America Case Study: Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4, LaFayette, Georgia (CZ4), and Savannah, Georgia (CZ2)

    Energy Technology Data Exchange (ETDEWEB)

    V. Kochkin, M. Sweet

    2017-02-01

    The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk of condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.

  2. Thermography and Sonic Anemometry to Analyze Air Heaters in Mediterranean Greenhouses

    Directory of Open Access Journals (Sweden)

    Araceli Peña

    2012-10-01

    Full Text Available The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while thermography provides accurate crop temperature data. Air distribution by means of perforated polyethylene ducts at ground level, widely used in Mediterranean-type greenhouses, can generate heterogeneous temperature distributions inside the greenhouse when the system is not correctly designed. The system analyzed in this work used a polyethylene duct with a row of hot air outlet holes (all of equal diameter that expel warm air toward the ground to avoid plant damage. We have observed that this design (the most widely used in Almería’s greenhouses produces stagnation of hot air in the highest part of the structure, reducing the heating of the crop zone. Using 88 kW heating power (146.7 W∙m−2 the temperature inside the greenhouse is maintained 7.2 to 11.2 °C above the outside temperature. The crop temperature (17.6 to 19.9 °C was maintained above the minimum recommended value of 10 °C.

  3. Thermography and sonic anemometry to analyze air heaters in Mediterranean greenhouses.

    Science.gov (United States)

    López, Alejandro; Valera, Diego L; Molina-Aiz, Francisco; Peña, Araceli

    2012-10-16

    The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while thermography provides accurate crop temperature data. Air distribution by means of perforated polyethylene ducts at ground level, widely used in Mediterranean-type greenhouses, can generate heterogeneous temperature distributions inside the greenhouse when the system is not correctly designed. The system analyzed in this work used a polyethylene duct with a row of hot air outlet holes (all of equal diameter) that expel warm air toward the ground to avoid plant damage. We have observed that this design (the most widely used in Almería's greenhouses) produces stagnation of hot air in the highest part of the structure, reducing the heating of the crop zone. Using 88 kW heating power (146.7 W ∙ m(-2)) the temperature inside the greenhouse is maintained 7.2 to 11.2 °C above the outside temperature. The crop temperature (17.6 to 19.9 °C) was maintained above the minimum recommended value of 10 °C.

  4. 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%

  5. Experimental study on a solar air heater with various perforated covers

    Indian Academy of Sciences (India)

    Raheleh Nowzari

    2017-08-08

    plate solar air heaters utilize solar energy to heat air. The low heat transfer coefficient between the air and the absorber plate reduces the thermal efficiency of solar air heaters. Another reason for the low thermal performance of.

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

    Science.gov (United States)

    2016-09-01

    climatic conditions and different air distribution systems types. Data on thermal energy and fan power was collected before and after the duct sealant...Expeditionary Warfare Center. This technology internally seals leaks in air distribution ducts by injecting a fog of aerosolized sealant particles...into a pressurized duct system. The product keeps the particles suspended within the air stream. As the duct work is pressurized, the particles

  7. 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.

  8. Comparative performance of coriander dryer coupled to solar air heater and solar air-heater-cum-rockbed storage

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, P.M.; Choudhury, C.; Garg, H.P. [Indian Inst. of Technology, Centre for Energy Studies, New Delhi (India)

    1996-03-01

    In the present communication, efforts have been made to study the drying characteristics of coriander in a stationary 0.5 tonne/batch capacity deep-bed dryer coupled to a solar air heater and a rockbed storage unit to receive hot air during sunshine and off-sunshine hours, respectively. The drying bed was assumed to consist of a number of thin layers of grains stacked upon each other. The theoretical investigation was made by writing the energy and mass balance equations for different components of the dryer-cum-air-heater-cum-storage and by adopting a finite difference approach for simulation. (author)

  9. 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.

  10. Determination of thermal performance of solar air heater

    OpenAIRE

    Kozak, Christina; Zhelykh, Vasil

    2013-01-01

    Considered the basic aspects of passive solar building. Given the main types of solar air heating systems. Proposed heating and ventilation system at the basis of solar air heater. Constructed fourfactors nomohram for determining thermal power of the thermosiphon heliocollector. Obtained analytical dependence of the amount heat of thermo heliocollector from the differential temprature air inlet and outlet, of the area input and output apertures of solar collector, heat fl...

  11. Optimization of air ducts for nuclear reactor power generation station

    International Nuclear Information System (INIS)

    Hirao, Katsumi; Yoshino, Hirokazu; Sonoda, Takayuki

    1991-01-01

    In the optimization study on the heating, ventilating and air conditions system in Nuclear Reactor Power Generation Station, proper arrangement of air ducts has been studied using the experimental and analytical investigation from a viewpoint of duct arrangement optimization. This study consists of two parts. Part I is optimization of air ducts in the corridors and Part II is optimization of air duct in each room. In part I, from viewpoints of confinement of radioactive materials in facilities having possible radioactive contamination and improvement of thermal environment for workers, the authors have studied air ducts system in which fresh air is supplied to corridors and heat removal and ventilation for each room are performed by transferring air from the corridors, instead of current ducts system with supply duct to each room. In part II, the condenser room with complex configuration and large space, and the electrical equipment room with simple space are selected for model areas. Based on these studies, experimental and analytical investigation (using a three-dimensional thermal hydraulic analysis) technique has been established, and the effective design method for duct arrangement of HVAC design has been verified for Boiling Water Reactor Power Station. The air-duct arrangements optimized in this study are applied to an Advanced Boiling Water Reactor Power Station in trial and reduction of the air-duct quantity is confirmed

  12. Performance simulation of a natural circulation solar air heater with ...

    African Journals Online (AJOL)

    Performance simulation of a natural circulation solar air heater with phase change material energy storage. ... The predicted temperatures of the system are compared with the experimental data under daytime no-load condition over the ambient temperature range of 18.5-36.0OC and daily global irradiation of ...

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

    African Journals Online (AJOL)

    The present paper studies the thermal performance of solar air heater which is artificially roughened by providing multiple arcs with gap shaped roughness element. As thermal efficiency of smooth collector is quite low, hence there is a need to augment heat transfer from the absorbing surface. The experimentation has ...

  14. 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.

  15. 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)

  16. 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.

  17. 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.

  18. Liquid films flowing concurrently with air in horizontal duct, 4

    International Nuclear Information System (INIS)

    Fukano, Tohru; Takamatsu, Yasuo; Akenaga, Hiroshi; Ikeda, Masayoshi; Itoh, Akihiko; Kuriwaki, Tessho.

    1984-01-01

    The effect of the aspect ratio of the duct cross-section on a liquid film flowing concurrently with an air stream was investigated using three horizontal ducts. The dimensions of the duct are 10 mm x 40 mm (height x width), 40 mm x 40 mm and 10 mm x 80 mm. The results are summarized as follows: The boundary of flow patterns between the pebble wave flow and the disturbance wave flow strongly depends on the duct height. On the other hand, the boundary between a smooth surface flow and a two-dimensional wave flow as well as the nonwetting regime depends mainly on the duct width. The reason is that the volumetric flux of the liquid flow in the vicinity of the side walls of the duct is considerably larger than that in the central part of the duct width due to the formation of meniscus. Therefore, only the experimental values for the film parameters obtained at the central part of duct width are useful for comparison with the theoretical results obtained by the assumption that the flow is two-dimensional, even if the aspect ratio of duct seems to be sufficiently small. (author)

  19. 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.

  20. Simulation analysis of air flow and turbulence statistics in a rib grit roughened duct.

    Science.gov (United States)

    Vogiatzis, I I; Denizopoulou, A C; Ntinas, G K; Fragos, V P

    2014-01-01

    The implementation of variable artificial roughness patterns on a surface is an effective technique to enhance the rate of heat transfer to fluid flow in the ducts of solar air heaters. Different geometries of roughness elements investigated have demonstrated the pivotal role that vortices and associated turbulence have on the heat transfer characteristics of solar air heater ducts by increasing the convective heat transfer coefficient. In this paper we investigate the two-dimensional, turbulent, unsteady flow around rectangular ribs of variable aspect ratios by directly solving the transient Navier-Stokes and continuity equations using the finite elements method. Flow characteristics and several aspects of turbulent flow are presented and discussed including velocity components and statistics of turbulence. The results reveal the impact that different rib lengths have on the computed mean quantities and turbulence statistics of the flow. The computed turbulence parameters show a clear tendency to diminish downstream with increasing rib length. Furthermore, the applied numerical method is capable of capturing small-scale flow structures resulting from the direct solution of Navier-Stokes and continuity equations.

  1. 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

  2. Effect of Preventive Maintenance on Performance of Air Heater in a Power Plant

    International Nuclear Information System (INIS)

    Jang, Jin Hyung; Hong, Eun Kee; Hwang, Kwang Won; Yun, Rin

    2010-01-01

    Air heater used in power plant helps increase the thermal efficiency of the boiler by recovering the heat from the boiler flue gas and thus preventing the loss of useful heat. This study investigates the effect of preventive maintenance on the performance of the air heater in a power plant. Performance indexes for the air heater are calculated to observe the changes in the performance and operation status of the air heater before and after preventive maintenance. The major performance indexes considered are temperature efficiency of the flue gas side, air leakage rate, heat recovery rate, heat transmission rate, and heat capacity ratio. The performance of the air heater is evaluated before and after preventive maintenance; our results show that all the above mentioned performance indexes are improved after the maintenance

  3. Post-Tensioning Duct Air Pressure Testing Effects on Web Cracking

    Science.gov (United States)

    2015-01-01

    Nevada Department of Transportation (NDOT) post-tensioned concrete bridges have experienced web cracking near the post-tensioning ducts during the construction process. The ducts were air pressure tested to ensure the duct can successfully be grouted...

  4. Air in the main pancreatic duct: a case of innocent air.

    Science.gov (United States)

    Kim, Yun Ji; Kim, Hyung Keun; Cho, Young Seok; Kim, Sung Soo; Chae, Hiun Suk; Kim, Seung Kyong; Kim, Eun Sun; Lee, Su Yeon

    2012-09-28

    Air in the main pancreatic duct has been reported only rarely and might be associated with either a spontaneous or a surgically induced alteration of the anatomy of the biliary tract. We report a case of "innocent" air found incidentally in the main pancreatic duct. To our knowledge, this is only the third such case reported. A 54-year-old woman presented with hemoptysis that had lasted for 3 d. She underwent a chest computed tomography scan, which revealed not only focal bronchiectasis in the left lower lobe, but also air in the main pancreatic duct and dilatation of the common bile duct. She was managed conservatively for the hemoptysis and no further problems developed. She had no specific gastrointestinal symptoms and had no history of surgery or medication. Her laboratory parameters were normal. Magnetic resonance cholangiopancreatography also demonstrated air in the main pancreatic duct and a dilated common bile duct (CBD). Duodenoscopy revealed separate biliary and pancreatic orifices with patulous openings and some air bubbles appearing in the pancreatic orifice. Endoscopic retrograde cholangiopancreatography (ERCP) showed the dilated CBD and pancreatic duct with some air bubbles, but no other abnormal lesions. She was discharged with no further problems. Most patients with air in the main pancreatic duct have had a pancreatobiliary disease, or a history of pancreatobiliary disease, pancreatobiliary surgery or sphincterotomy. If the air is innocent, as in our case, ERCP should be performed to evaluate any altered sphincteric function or anatomy such as patulous openings.

  5. Experimental study on a solar air heater with various perforated covers

    Indian Academy of Sciences (India)

    Raheleh Nowzari

    2017-08-08

    Aug 8, 2017 ... heater with the quarter-perforated cover was slightly higher than that of the one with the half-perforated cover for both single- ... At the same mass flow rate, the average efficiency of the double-pass air heater with normal cover was. 50.92%. ...... characteristics via baffle blocks in a proton exchange mem-.

  6. 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)

  7. Low-noise flow valve for air ducts

    Science.gov (United States)

    Gallo, E. A.

    1970-01-01

    Valve assembly controls air flow from feeder into main duct, with minimum of turbulence, friction, pressure differential, and noise. Valve consists of damper, deflector, and spring. Streamlining of damper and deflector merges flow smoothly, while spring keeps damper and deflector in contact and eliminates valve chatter and damping vibrations.

  8. The transmission of thermal neutrons along air filled ducts in water

    International Nuclear Information System (INIS)

    Piercey, D.C.

    1962-06-01

    Predictions and measurements of thermal neutron transmission along air filled ducts in water have been made. To aid the analysis, the ducts were shielded in various ways using cadmium sheet. The predictions were, in general, in agreement to better than a factor 4 for ducts up to 200 duct radii in length. (author)

  9. 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.

  10. Studi Eksperimen Pengaruh Variasi Kecepatan DanTemperatur Air Heater Terhadap Karakteristik Pengeringan Batubara Pada Coal Dryer Dengan Tube Heater Tersusun Aligned

    OpenAIRE

    Pakarti, Anindya Ayu; Ichsani, Djatmiko

    2013-01-01

    Salah satu model pengeringan batubara adalah coal dryer yang memberikan keuntungan seperti tingginya tingkat perpindahan panas dan massa.Dari penelitian ini dapat diketahui karakteristik pengeringan pada ruang pengering batubara dengan tube heater tersusun aligned. Hasil eksperimen kuantitatif menunjukkan peningkatan temperatur air heater diikuti dengan penurunan moisture content batubara dan peningkatan drying rate. Pengurangan moisture content terbesar dan drying rate tertinggi didapatkan ...

  11. 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.

  12. 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.

  13. Energy and exergy analysis in double-pass solar air heater

    Indian Academy of Sciences (India)

    The effect of varied mass flow rate and solar intensity on temperature rise of air, energy efficiency, exergy gain and pressure drop at steady state condition was determined for different types of solar air heaters utilizing an indoor solar simulator. The temperature rise of air, thermal efficiency and exergy gain depends on mass ...

  14. Cooling air recycling for gas turbine transition duct end frame and related method

    Science.gov (United States)

    Cromer, Robert Harold; Bechtel, William Theodore; Sutcu, Maz

    2002-01-01

    A method of cooling a transition duct end frame in a gas turbine includes the steps of a) directing cooling air into the end frame from a region external of the transition duct and the impingement cooling sleeve; and b) redirecting the cooling air from the end frame into the annulus between the transition duct and the impingement cooling sleeve.

  15. The influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation.

    OpenAIRE

    Jícha M.; Fišer J.

    2013-01-01

    The paper deals with instigation of influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation. CFD approach was used for investigation and model geometry was based on small aircraft cabin mock-up geometry. Model was also equipped by nine seats and five manikins that represent passengers. The air jet direction was observed for selected ambient environment parameters and several types of air duct geometry and influence of main air duct geometry on je...

  16. MHD air heater development technology. Report for the period April 1978-June 1978

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-12-01

    This research program is divided into three tasks. Task 1 (design studies): the objectives of this task are to: (1) evaluate full-scale, direct- and indirect-fired regenerative air heater systems for use in MHD power plants; (2) support testing of refractory materials, hot gas valves, and design concepts; (3) support design of a 5 MW test heater. Task 2 (design support tests): the objectives of this task are to: (1) support design of a 5 MW test heater; (2) identify and evaluate life of promising refractory materials for use in MHD heaters; (3) determine operating conditions and bed geometry (hole size, web thickness) which permit operation without clogging of heater passages due to accumulations of seed/slag or slag alone, (4) test valves for use in hot gas streams which are laden with seed/slag or slag alone. Task 3 (vertical slice test bed): the objective of this task is to provide a preliminary design of a test heater which is a vertical slice of a full-scale heater. It will be sized for a thermal input of 5 MW. Testing with hot gas streams containing seed/slag or slag alone will be accommodated in order to simulate both direct- and indirect-firing. Progress on each of these tasks is described. (WHK)

  17. Energy and exergy analysis in double-pass solar air heater

    Indian Academy of Sciences (India)

    P VELMURUGAN

    paint spraying operations. Numerous solar air heating devices have been devel- oped and used experimentally. The effects of materials and construction of the absorber upon the energy and exergy per- formance of the solar air heaters were also reported in the literature widely. Sopian et al [1] conducted indoor experi-.

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

    African Journals Online (AJOL)

    2017-01-17

    Jan 17, 2017 ... For low temperature solar heating applications two kind of solar air ... very low heat transfer rate because of small exchange surfaces ... In the study, mean temperatures and thermal performances of the solar air heater are modelled in quasi-steady state and compared to experimental data. Nomenclature.

  19. 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)

  20. Automatic air flow control in air conditioning ducts

    Science.gov (United States)

    Obler, H. D.

    1972-01-01

    Device is designed which automatically selects air flow coming from either of two directions and which can be adjusted to desired air volume on either side. Device uses one movable and two fixed scoops which control air flow and air volume.

  1. MHD air heater development technology. Progress report, November 26, 1979-March 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-05-01

    Work on the development of the directly-fired high temperature air heater (HTAH) for MHD power plants is reported. Progress is reported on three tasks: (1) materials selection, evaluation, and development, (2) operability, performance, and materials testing, and (3) full-scale design concepts. Under Task 1, efforts were carried out in several areas. Work on the computer data base for material properties was begun. Data were compiled for several HTAH materials. Materials selections for Valve Test 3 and full-scale studies were made. Test conditions were defined for and creep results obtained from Montana College of Mineral Science and Technology concerning candidate matrix and hot liner materials. Liaison efforts with refractory manufacturers were continued, and information was provided to Argonne National Laboratory and Babcock and Wilcox concerning the HRSR design. Analyses of materials samples from previous matrix and valve tests were completed. Finally, a thermal stress cycling experiment to be carried out at Montana Tech was designed. Under Task 2, efforts were directed toward running Valve Test 3. Problems were encountered with the VTF hot gas supply duct which necessitated two intermediate shutdowns without reaching the final test goal of 300 hours. Modifications necessary to complete the test were begun. Under Task 3, an example HTAH system was defined which will be used as a focal point for screening and definition of control systems and determination of operating methods. The system was defined using the size/cost and other HTAH computer codes. A layout of the system was made, and steady state performance was calculated with the SCAMP code. (WHK)

  2. 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.

  3. 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.

  4. Air in the main pancreatic duct: A case of innocent air

    OpenAIRE

    Kim, Yun Ji; Kim, Hyung Keun; Cho, Young Seok; Kim, Sung Soo; Chae, Hiun Suk; Kim, Seung Kyong; Kim, Eun Sun; Lee, Su Yeon

    2012-01-01

    Air in the main pancreatic duct has been reported only rarely and might be associated with either a spontaneous or a surgically induced alteration of the anatomy of the biliary tract. We report a case of “innocent” air found incidentally in the main pancreatic duct. To our knowledge, this is only the third such case reported. A 54-year-old woman presented with hemoptysis that had lasted for 3 d. She underwent a chest computed tomography scan, which revealed not only focal bronchiectasis in th...

  5. Energy and exergy analysis in double-pass solar air heater

    Indian Academy of Sciences (India)

    P VELMURUGAN

    Abstract. In this study, an attempt is made to improve the energy and exergy performance of solar air heater by employing double pass with different absorber surface geometries (roughened, finned, and v-corrugated wire mesh) in the second pass, and also by mounting longitudinal fins in the back side of the absorber plate ...

  6. 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 ...

  7. 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.

  8. High speed flow of air-oil mixtures in converging-diverging ducts

    International Nuclear Information System (INIS)

    George, C.M.; Poulikakos, D.; Bowman, J.

    1991-01-01

    This paper presents a theoretical model for the high speed flow of homogeneous air-oil mixtures through converging - diverging ducts. This model is used to investigate the effects of friction, oil density, oil mass fraction in the mixture, duct throat clearance, and duct geometry, on the flowrate through the duct. The results indicate that for homogeneous mixtures the effect of the density is marginal. On the other hand, it was found that the surface friction, the size of throat clearance, and the duct geometry affected significantly the mass flowrate. Increasing the gas to liquid mass ratio increases the leakage. This effect diminishes at large values of the mass ratio

  9. Fan Duct Heat Exchanger for Turbine Cooling Air, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposal is for the design of a fan duct heat exchanger in order to improve aircraft fuel burn. The fan duct heat exchanger decreases the temperature of the 15%...

  10. 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)

  11. 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.

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

    OpenAIRE

    Sanjeev Jakhar; Rohit Misra; M.S. Soni; Nikhil Gakkhar

    2016-01-01

    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, ...

  13. Addition of inexpensive solar air-heaters to a pre-engineered metal building. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, R E; McClendon, R W

    1979-05-01

    At Mississippi State University a research project was begun in 1976 to investigate the use of site-built solar collectors for heating air in poultry houses. The purpose of this work was to design and test a functional air heater solar collector which would be inexpensive to construct and acceptable to poultry producers. The results reported are an extension of the original concept. The basic concept is to use a pre-engineered metal building for the structure and incorporate the solar air heaters as an integral part of the south facing wall of the building. The outer skin of the building is used as the absorber plate for the collctors. Construction and testing of the solar collectors and heat storage systems are discussed, and the performance characteristics of the site-built solar collectors are described. (WHK)

  14. The influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation.

    Directory of Open Access Journals (Sweden)

    Jícha M.

    2013-04-01

    Full Text Available The paper deals with instigation of influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation. CFD approach was used for investigation and model geometry was based on small aircraft cabin mock-up geometry. Model was also equipped by nine seats and five manikins that represent passengers. The air jet direction was observed for selected ambient environment parameters and several types of air duct geometry and influence of main air duct geometry on jets direction is discussed. The model was created in StarCCM+ ver. 6.04.014 software and polyhedral mesh was used.

  15. 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.

  16. Air in the main pancreatic duct associated with a pancreatic intraductal papillary mucinous neoplasm.

    Science.gov (United States)

    Yamamoto, Satoshi; Inui, Kazuo; Yoshino, Junji; Miyoshi, Hironao; Kobayashi, Takashi

    2013-12-01

    A 62-year-old man was referred to our hospital after ultrasonographic mass screening detected a pancreatic cyst that proved to be an intraductal papillary mucinous neoplasm. Computed tomography additionally demonstrated air in the main pancreatic duct. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography delineated a filling defect in the main pancreatic duct in the body of the pancreas. The sphincter of Oddi was open. The main pancreatic duct was dilated by viscous mucin; air in the duct was attributed to consequent dysfunction of the sphincter. Laboratory findings included no significant abnormality. The patient has remained asymptomatic during follow-up. Of 25 previously reported cases with air in the duct, only 1 involved an intraductal papillary mucinous neoplasm.

  17. Finding the best configuration for a solar air heater by design and analysis of experiment

    International Nuclear Information System (INIS)

    Nowzari, Raheleh; Mirzaei, Nima; Aldabbagh, L.B.Y.

    2015-01-01

    Highlights: • The theoretical and experimental study on a solar air heaters with different configurations were performed. • Design and analysis of experiment was used to analyze the data from experiment. • Agreement between theoretical and empirical results, verified the exactness of the experimental design. • The highest efficiency was obtained from double pass solar collector with quarter perforated 10D cover. - Abstract: An experimental investigation was performed on a solar air heater with different configurations. The configurations included testing the single- and double-pass solar collectors with normal and perforated covers and with wire mesh layers instead of an absorber plate. Design and analysis of experiment was used to develop a model for the tested solar air heater and IBM’s Statistical Package for the Social Sciences software was used to analyze the model. Strong agreement was found between the results obtained from the theoretical and experimental investigations. Both methods suggested the same configuration for attaining the highest thermal efficiency from the system, i.e., a double-pass solar collector with a quarter-perforated cover with 3-cm hole-to-hole spacing and a mass flow rate of 0.032 kg/s

  18. 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.

  19. A solar air heater with composite-absorber systems for food dehydration

    Energy Technology Data Exchange (ETDEWEB)

    Madhlopa, A. [Malawi Polytechnic, Blantyre (Malawi). Dept. of Applied Sciences; Jones, S.A. [Chancellor College, Zomba (Malawi). Physics Dept.; Kalenga Saka, J.D. [Chancellor College, Zomba (Malawi). Chemistry Dept.

    2002-09-01

    Development of appropriate technologies for conversion of solar radiation to thermal energy is essential for food preservation. A solar air heater, comprising two absorber systems in a single flat-plate collector, was designed on the principles of psychrometry. The heater was integrated to a drying chamber for food dehydration. This collector design offered flexibility in manual adjustment of the thermal characteristics of the solar dryer. The performance of the dryer was evaluated by drying fresh samples of mango (Mangifera indicus). Both fresh and dried mango samples were analysed for moisture content (MC), pH and ascorbic acid. During the dehydration period, meteorological measurements were made. The air heater converted up to 21.3% of solar radiation to thermal power, and raised the temperature of the drying air from about 31.7{sup o}C to 40.1{sup o}C around noon. The dryer reduced the MC of sliced fresh mangoes from about 85% (w/w) to 13% (w/w) on wet basis, and retained 74% of ascorbic acid. It was found that the dryer was suitable for preservation of mangoes and other fresh foods. (author)

  20. 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.

  1. MHD air heater technology development. Annual technical progress report, January 1, 1980-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-03-01

    Progress on the technology development of the directly-fired high temperature air heater (HTAH) for MHD power plants is described in detail. The objective of task 1 is to continue development of ceramic materials technology for the directly-fired HTAH. The objectives of task 2 are to demonstrate the technical feasibility of operating a directly-fired HTAH (including both the heater matrix and valves), to continue obtaining information on life and corrosion resistance of HTAH materials, and to obtain design information for full-scale studies and future design work. The objectives of task 3 are to begin the identification of HTAH control requirements and control system needs, and to continue full-scale study efforts incorporating updated materials and design information in order to identify development needs for the HTAH development program. (WHK)

  2. MHD air heater development technology. Technical progress report, July 1-September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-11-01

    The technology development of the directly-fired high temperature air heater (HTAH) for MHD power plants is described. Progress is reported on the three tasks. The first task is materials selection, evaluation, and development. The objective of this task is to continue development of ceramic materials technology for the directly-fired HTAH. Task two is operability, performance, and materials testing. The objectives of this task are to demonstrate the technical feasibility of operating a directly-fired HTAH (including both the heater matrix and valves), to continue obtaining information on life and corrosion resistance of HTAH materials, and to obtain design information for full-scale studies and future design work. The objectives of the full-scale design task are to begin the identification of HTAH control requirements and control system needs, and to continue full-scale study efforts incorporating updated materials and design information in order to identify development needs for the HTAH development program. (WHK)

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Limit strength of rectangular air ventilation ducts under-seismic design condition

    International Nuclear Information System (INIS)

    Kato, T.; Nakatogawa, T.; Ichihashi, I.; Takenaka, M.; Nomura, T.

    1989-01-01

    The precise estimation of the limiting strength of heating, ventilating, and air conditioning ducts used in nuclear power plants is a key to the safe and economical design of the seismic supports. The formula for estimating the strength of ducts used up to this time, was derived from test results from small size ducts less than 500mm square. This data was extrapolated to obtain the strength of large ducts and therefore big margins had to be used. Consequently the seismic support spans of rectangular ducts are short and a large bulk volume of seismic support spans rectangular ducts are short and a large bulk volume of seismic support material is used in nuclear power plants. Accordingly, the authors carried out overall pure bending moment tests, shearing load tests, and local buckling load tests using large size rectangular ducts. In this paper the authors present the results of these tests and a method of designing seismic supports safely and economically by using the duct limiting strength estimation formula obtained from these tests

  8. 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

    2013-01-01

    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. PMID:25685486

  9. 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)

  10. 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%.

  11. 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

  12. 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.

  13. 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%.

  14. Dust deposition in ventilation and air-conditioning duct bend flows

    International Nuclear Information System (INIS)

    Gao Ran; Li Angui

    2012-01-01

    Highlights: ► We study particle deposition on the four inner surface of the duct bend. ► We analyse the effect of five ways of placements of the bend on particle deposition. ► Gravity and inertia force enhance the deposition as relaxation time rises. ► Deposition coefficient increases as air velocity or particle diameter increases. - Abstract: Particles carried by airflows in ventilation and air-conditioning systems have adverse effects on the quality of air in buildings and hence the health of building occupants. Gaining insight on particle deposition onto ventilation and air-conditioning duct bends is important for controlling pollutant dispersion. Based on the Reynolds stress transport model (RSM), this paper has taken into account the effects of drag, lift force, gravity, inertia force, turbulent diffusions, particle size and air velocity on the dimensionless deposition velocity of particles in smooth duct bends using fully developed velocity profiles. At two different air velocities of 3.0 m/s and 7.0 m/s, the aforementioned effects were predicted by Reynolds-averaged Navier–Stokes (RANS)-Lagrangian simulation on square shaped duct bends with different ways of placement. Preliminary results suggest that gravity and inertia force enhance the dimensionless deposition as dimensionless relaxation time rises. Change tendency of the dimensionless particle deposition velocity on different surfaces of bend duct agrees well with previous studies. As air velocity and particle diameter increase, a significant increase of particle deposition coefficient in the duct bends is observed. Particle deposition to intrados can be intensified by the combined action of gravity and inertia force in different direction.

  15. 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.

  16. 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)

  17. Spectrum measurement of fast neutron through air ducts in water, concrete, and lead

    International Nuclear Information System (INIS)

    Jiang, S.H.; Lin, G.L.; Wu, S.Y.; Liaw, S.Y.

    1983-01-01

    Fast neutron spectral through straight air ducts in water, concrete, and lead have been measured from 1 to 12 MeV by using an NE-213 spectrometer. Wall scattered component has been abstracted from the measured data. It was found that Simon and Clifford's equation can not be applied to describe the measured flux perhaps mainly due to the inadequate assumption of angular distribution of reflected neutrons. The ratio of wall-scattered component to line-of-sight component was found to be dependent on the duct length more or less with an inverse square proportionality for ducts in water and concrete and with an inverse cubic or even more strong proportionality for ducts in lead. (author)

  18. Effect of gas and kerosene space heaters on indoor air quality: a study in homes of Santiago, Chile.

    Science.gov (United States)

    Ruiz, Pablo A; Toro, Claudia; Cáceres, Jorge; López, Gianni; Oyola, Pedro; Koutrakis, Petros

    2010-01-01

    The impact of outdoor and indoor pollution sources on indoor air quality in Santiago, Chile was investigated. Toward this end, 16 homes were sampled in four sessions. Each session included an outdoor site and four homes using different unvented space heaters (electric or central heating, compressed natural gas, liquefied petroleum gas, and kerosene). Average outdoor fine particulate matter (PM2.5) concentrations were very high (55.9 microg x m(-3)), and a large fraction of these particles penetrated indoors. PM2.5 and several PM2.5 components (including sulfate, elemental carbon, organic carbon, metals, and polycyclic aromatic hydrocarbons) were elevated in homes using kerosene heaters. Nitrogen dioxide (NO2) and ultrafine particles (UFPs) were higher in homes with combustion heaters as compared with those with electric heaters or central heating. A regression model was used to assess the effect of heater use on continuous indoor PM2.5 concentrations when windows were closed. The model found an impact only for kerosene heaters (45.8 microg m(-3)).

  19. Heat Transfer and Friction Characteristics of Artificially Roughened Duct used for Solar Air Heaters—a Review

    Science.gov (United States)

    Kumar, Khushmeet; Prajapati, D. R.; Samir, Sushant

    2018-02-01

    Solar air heater uses the energy coming from the sun to heat the air. The conversion rate of solar energy to heat depends upon the efficiency of the solar air heater and this efficiency can be increased by the use of artificial roughness on the surface of absorber plate. Various studies were carried out to analyse the effect of different roughness geometries on heat transfer and friction factor characteristics. The thermo-hydraulic performance of solar air heater can be evaluated in terms of effective efficiency, thermo-hydraulic performance parameter and exergetic efficiency. In this study various geometries used for artificial roughness and to improve the performance of solar air heaters were studied. Also correlations developed by various researchers are presented in this paper.

  20. Design and analysis of Air flow duct for improving the thermal performance of disc brake rotor

    Science.gov (United States)

    Raja, T.; Mathiselvan, G.; Sreenivasulureddy, M.; Goldwin Xavier, X.

    2017-05-01

    safety in automotive engineering has been considered as a number one priority in development of new vehicle. A brake system is one of the most critical systems in the vehicle, without which the vehicle will put a passenger in an unsafe position. Temperature distribution on disc rotor brake and the performance brake of disc rotor is influenced by the air flow around the disc rotor. In this paper, the effect of air flow over the disc rotor is analyzed using the CFD software. The air flow over the disc rotor is increased by using a duct to supply more air flow over the disc rotor. The duct is designed to supply more air to the rotor surface and it can be placed in front of the vehicle for better performance. Increasing the air flow around the rotor will maximize the heat convection from the rotor surface. The rotor life and the performance can be improved.

  1. 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...

  2. MHD air heater development technology. Technical progress report, April 1, 1980-June 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    Technology development for the directly-fired high temperature air heater (HTAH) for MHD power plants is described. Work is being done under three tasks as described in the following. (1) materials selection, evaluation, and development: The objective of this task is to continue development of ceramic materials technology for the directly-fired HTAH. The scope of the work will include compilation of materials data, materials selection for testing and design studies, materials property determination, liaison with refractory manufacturers and other organizations to encourage development of materials and fabrication technology, establishment of preliminary HTAH material specifications, analyses of test materials, and development of criteria for thermal stress limits for crack-tolerant refractory materials. (2) operability, performance, and materials testing: The objectives of this task are to demonstrate the technical feasibility of operating a directly-fired HTAH (including both the heater matrix and valves), to continue obtaining information on life and corrosion resistance of HTAH materials, and to obtain design information for full-scale studies and future design work. (3) full-scale design concepts: The objectives of this task are to begin the identification of HTAH control requirements and control system needs, and to continue full-scale study efforts incorporating updated materials and design information in order to identify development needs for the HTAH development program. Progress is described. (WHK)

  3. Modification of the inlet to the tertiary air duct in the cement kiln installation

    OpenAIRE

    Borsuk Grzegorz; Wydrych Jacek; Dobrowolski Bolesław

    2016-01-01

    Rotary kiln installation forms a very complex system, as it consists of various components which affect cement production. However, some problems with particle settling are encountered during operation of tertiary air installation. This paper reports on the results of a study into gas-particle flow in a tertiary air duct installation. This flow was calculated using Euler method for air motion and Lagrange method for particle motion. The results in this paper demonstrate that study focus on th...

  4. 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.

  5. Exergoeconomic Design of the Geometry of a Vertical, Three Steps, Tubular Air Heater

    Directory of Open Access Journals (Sweden)

    J.J. Marín–Hernández

    2009-10-01

    Full Text Available In this paper, the structural method of thermoeconomics is applied to find the optimal geometrical design to a vertical tubular air heater, whose original design is widely used on boilers installed on sugar mills. The objective function describes the running cost due to the temperature difference and pressure drop in function of the main geometrical parameters. The objective function is continuous in the interval of analysis and has a strong non linear behavior, then for solving it, the Optimization Toolbox from MATLAB 6.5 was used, through the function FMINCON, which uses an algorithm of medium scale, the Sequential Quadratic Programming (SQP and the Cuasi Newton method. The new design reduces the running cost of equipment 1,97 US$/s compared to the one of RETO 45–28 system.

  6. 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.

  7. Development of an Ultrasonic Airflow Measurement Device for Ducted Air

    Science.gov (United States)

    Raine, Andrew B.; Aslam, Nauman; Underwood, Christopher P.; Danaher, Sean

    2015-01-01

    In this study, an in-duct ultrasonic airflow measurement device has been designed, developed and tested. The airflow measurement results for a small range of airflow velocities and temperatures show that the accuracy was better than 3.5% root mean square (RMS) when it was tested within a round or square duct compared to the in-line Venturi tube airflow meter used for reference. This proof of concept device has provided evidence that with further development it could be a low-cost alternative to pressure differential devices such as the orifice plate airflow meter for monitoring energy efficiency performance and reliability of ventilation systems. The design uses a number of techniques and design choices to provide solutions to lower the implementation cost of the device compared to traditional airflow meters. The design choices that were found to work well are the single sided transducer arrangement for a “V” shaped reflective path and the use of square wave transmitter pulses ending with the necessary 180° phase changed pulse train to suppress transducer ringing. The device is also designed so that it does not have to rely on high-speed analogue to digital converters (ADC) and intensive digital signal processing, so could be implemented using voltage comparators and low-cost microcontrollers. PMID:25954952

  8. Development of an Ultrasonic Airflow Measurement Device for Ducted Air

    Directory of Open Access Journals (Sweden)

    Andrew B. Raine

    2015-05-01

    Full Text Available In this study, an in-duct ultrasonic airflow measurement device has been designed, developed and tested. The airflow measurement results for a small range of airflow velocities and temperatures show that the accuracy was better than 3.5% root mean square (RMS when it was tested within a round or square duct compared to the in-line Venturi tube airflow meter used for reference. This proof of concept device has provided evidence that with further development it could be a low-cost alternative to pressure differential devices such as the orifice plate airflow meter for monitoring energy efficiency performance and reliability of ventilation systems. The design uses a number of techniques and design choices to provide solutions to lower the implementation cost of the device compared to traditional airflow meters. The design choices that were found to work well are the single sided transducer arrangement for a “V” shaped reflective path and the use of square wave transmitter pulses ending with the necessary 180° phase changed pulse train to suppress transducer ringing. The device is also designed so that it does not have to rely on high-speed analogue to digital converters (ADC and intensive digital signal processing, so could be implemented using voltage comparators and low-cost microcontrollers.

  9. 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.

  10. 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.

  11. 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)

  12. Engineering analyses and design calculations of NASA, Langley Research Center hydrogen-air-vitiated heater with oxygen replenishment

    Science.gov (United States)

    1973-01-01

    The technical basis is presented for the design of the hydrogen-air-vitiated heater. The heater liner is subjected to a maximum thermal environment at a specified condition, where the combustion gas temperature, pressure and flow rate are 5000 F, 750 psia, and 11.0 lb/sec, respectively, and results in a heat flux of the order of 275 BTU/sec-sq ft. Cooling and stress analyses indicate that water is the logical choice for cooling of the combustor liner. A mixing analysis was undertaken to establish a good combination of combustor length and injector configuration. The analysis, using a conservative analytical approach, indicates a combustor length of the order of 5 ft combined with discrete fuel and oxidizer injection at an approximate 2-1/2 inch radial combustor position, and results in uniform combustion products at the heater exit for all specified envelope conditions.

  13. Modification of the inlet to the tertiary air duct in the cement kiln installation

    Directory of Open Access Journals (Sweden)

    Borsuk Grzegorz

    2016-12-01

    Full Text Available Rotary kiln installation forms a very complex system, as it consists of various components which affect cement production. However, some problems with particle settling are encountered during operation of tertiary air installation. This paper reports on the results of a study into gas-particle flow in a tertiary air duct installation. This flow was calculated using Euler method for air motion and Lagrange method for particle motion. The results in this paper demonstrate that study focus on the tertiary air installation is a practical measure without the analysis of other processes in the rotary kiln. A solution to this problem offers several alternatives of modifying the inlet to the tertiary air duct. As a result of numerical calculations, we demonstrate the influence of geometry of a rotary kiln modification on the number of large particles transported in the tertiary air duct. The results indicate that in order to reduce large particles, rotary kiln head geometry needs to be modified, and a particle settler should be installed at its outlet.

  14. Advanced Strategy Guideline. Air Distribution Basics and Duct Design

    Energy Technology Data Exchange (ETDEWEB)

    Arlan Burdick

    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.

  15. 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.

  16. 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

  17. Should You Have the Air Ducts in Your Home Cleaned?

    Science.gov (United States)

    ... your indoor air. You have probably seen an advertisement, received a coupon in the mail, or been ... Contact Us Hotlines FOIA Requests Frequent Questions Follow. Facebook Twitter YouTube Flickr Instagram Last updated on April ...

  18. STRUCTURAL LEAF CHANGES IN TREES AROUND A SUBWAY AIR DUCT

    OpenAIRE

    Rodrigues, Renato de Aragão Ribeiro; Vaz, Vanderson Corrêa; Sato, Alice; Arruda, Rosani do Carmo de Oliveira; Castro, Wagner Antonio Chiba de; Silva-Matos, Dalva Maria da

    2015-01-01

    ABSTRACTWhile a number of papers have shown that subway systems have an impact on the air quality through the release of particulate matters, no information about the impact of such particles on tree attributes is available. Tree leaves from three different species from the exit side of a subway station in Rio de Janeiro, Brazil, were more asymmetrical than leaves from the entrance side. This leaves also presenting changes in leaves cuticle and chlorophyll content. RESUMOVários artigos vêm...

  19. Structural leaf changes in trees around a subway air duct.

    OpenAIRE

    RODRIGUES, R. de A. R.; VAZ, V. C.; SATO, A.; ARRUDA, R. do C. de O.; CASTRO, W. A. C. de; SILVA-MATOS, D. M. da.

    2016-01-01

    ABSTRACTWhile a number of papers have shown that subway systems have an impact on the air quality through the release of particulate matters, no information about the impact of such particles on tree attributes is available. Tree leaves from three different species from the exit side of a subway station in Rio de Janeiro, Brazil, were more asymmetrical than leaves from the entrance side. This leaves also presenting changes in leaves cuticle and chlorophyll content.

  20. STRUCTURAL LEAF CHANGES IN TREES AROUND A SUBWAY AIR DUCT

    Directory of Open Access Journals (Sweden)

    Renato de Aragão Ribeiro Rodrigues

    2015-06-01

    Full Text Available ABSTRACTWhile a number of papers have shown that subway systems have an impact on the air quality through the release of particulate matters, no information about the impact of such particles on tree attributes is available. Tree leaves from three different species from the exit side of a subway station in Rio de Janeiro, Brazil, were more asymmetrical than leaves from the entrance side. This leaves also presenting changes in leaves cuticle and chlorophyll content.

  1. Summary of Public Comments and Responses for Industrial, Commercial, and Institutional Boilers and Process Heaters National Emission Standards for Hazardous Air Pollutants (NESHAP) for Major Sources

    Science.gov (United States)

    This page has a 12/2012 document that provides EPA’s responses to public comments on EPA’s Proposed National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters

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

    OpenAIRE

    Onur Çelikkan; Haluk Erol

    2017-01-01

    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 experim...

  3. 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.

  4. 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.

  5. High-speed Tests of a Ducted Body with Various Air-outlet Openings

    Science.gov (United States)

    Becker, John V.; Baals, Donald D.

    1942-01-01

    Test of a ducted body with Internal flow were made in the 8-foot high-speed wind tunnel for the purpose of studying the effects on external drag and an critical speed of the addition of efficient inlet and outlet openings to a basic streamline shape. Drag tests of a 13.6- inch-diameter streamline body of fineness ratio 6.14 were made at Mach numbers ranging from 0.20 to 0.75. The model was centrally mounted on a 9-percent-thick airfoil and was designed to have an efficient airfoil-body juncture and a high critical speed. An air inlet at the nose and various outlets at the tail were added: drag and internal-flow data were obtained over the given speed range. The critical speed of the ducted bodies was found to be as high as that of the streamline body. The external - drag with air flow through the body did not exceed the drag of the basic streamline shape. No appreciable variation in the efficiency of the diffuser section of the internal duct occurred throughout the Mach number range of the tests.

  6. Flow characteristics of air in square duct using delta wing vortex generators

    Directory of Open Access Journals (Sweden)

    Mahesh R. Ingalagi

    2016-09-01

    Full Text Available Performance improvement in terms of improving heat transfer coefficient and reducing pressure drop becomes essential in heat exchange applications and a large number of methods for reducing pressure drop exist in the literature and the present work is an investigation on use of delta wings as vortex generators for reducing pressure drop. Methodology includes air from a blower entering the test section through orificemeter and differential-micro manometer to measure the flow rate and pressure drop across the test section. Depending upon the pressure drops, friction factors for smooth and rough surface of the duct are estimated. The effect of geometrical parameters of delta wing and duct aspect ratio on friction factor ratios are reported Based on Reynolds number in the range of 8000−24000. The geometrical parameters of vortex generators varied in this study were the pitch-to-vortex generator height ratio (p/e, vortex generator height to duct hydraulic diameter ratio (e/Dh, aspect ratio of vortex generator (ar. Results are reported for 0.1 < e/Dh < 0.5, p/e = 4,8,12,16, (ar = 1.6,2.3,4, N = 1 in ducts having aspect ratio AR = 1, Detailed friction factor analysis for Re 8000−24000 has been presented for different configurations of vortex generators used in the square duct. The experimental results of the present study for friction factor in smooth square duct matches well with values taken from formula proposed by Blasius. The friction factor ratio increases with increase in e/Dh value, which may be attributed to increased blockage of the flow passage. For a given p/e, increasing e/Dh ratio for the same (ar has the effect of increasing circulation strength and core size of the vortex thereby offering more resistance to flow that results into a higher friction factor ratio. The results have been presented in the form of the friction factor ratio of the roughened and smooth ducts operating at equal Reynolds numbers. Semi

  7. 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.

  8. The study of flow and heat transfer characteristics of impinging jet array mounting air-induced duct

    Science.gov (United States)

    Yeranee, K.; Wae-hayee, M.; Piya, I.; Rao, Y.; Nuntadusit, C.

    2017-09-01

    Impinging jet is widely employed in thermal industrial applications due to having high heat transfer coefficient in impingement region. One method to increase heat transfer on an impingement surface is to increase turbulence intensity in jet flow. The mounting of an air-induced duct at nozzle outlet is a passive method to increase entrainment air resulting on increasing turbulence intensity. The aim of this research is to study flow and heat transfer characteristics of array of impinging jets mounting air-induced ducts. The investigation model was jets discharging from pipe nozzle having an inner diameter of d=17.2 mm and a length of 200 mm. Nozzle arrangement were inline configuration having 5 rows x 5 columns. A jet-to-jet distance (S) was S=6d, 8d and a jet-to-plate distance (H) was H=6d. The inner diameter (D) and the length (L) of the air-induced ducts were D=4d and L=4d, respectively. The Reynolds number was fixed at Re=20,000. In addition, the impinging jets without mounting the air-induced ducts were also investigated for benchmarking with the case of mounting the air-induced ducts. In the study, a thin foil technique was used to measure heat transfer on the impingement surface, and a computational fluid dynamic (CFD) using ANSYS, Fluent (V.15.0) was also adopted. The results showed that the effect of mounting air-induced duct can enhance entrainment air into the jet flow resulting on increasing of heat transfer of impinging jets on target surface, and the effects of mounting air-induced duct on increasing heat transfer in case of larger jet-to-jet distance (S/d=8) was more effective than that of smaller jet-to-jet distance (S/d=6).

  9. 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.

  10. ANALYSES OF RADIATION OF ELECTROMAGNETIC WAVES IN THE HIGH-VOLTAGE AIR DUCT (150 kV CONSTRUCTION ON HEALTH

    Directory of Open Access Journals (Sweden)

    Erwin Azizi Jayadipraja

    2017-12-01

    Full Text Available Background: High-voltage air ducts is the government program to supply electricity needs. However, in practice, obstacles have been identified in the form of rejection from the community due to the outstanding issues that high-voltage air ducts have an impact on health. Aim: This research aims to analysis the magnitude of electromagnetic wave radiation of high-voltage air ducts construction on health. Methods: The study was conducted by measuring electromagnetic wave radiation prior to high-voltage air ducts (150 kV construction and predicting the amount of radiation generated after this operation and its impact on health. Result: The field measurement result showed that the highest strength of magnetic field in the absence of construction and operation activity of high-voltage air ducts 150 kV was 0.00085 mT and the highest electric field was 0.004241251 V/m. The results of the magnetic field strength analysis showed that the highest strength of magnetic field and electric field when the high-voltage air ducts is completed and operated was magnetic field of 0.00415 mT and electric field of 38.4 V/m. The value was far lower than the standard limits recommended by IRPA / INIRC, WHO1990 and SNI 04-6950-2003. The allowed electric field strength is 5 kV / m and the allowed magnetic field strength is 0.1 mT. Conclusion: Electromagnetic wave radiation of High-Voltage Air Ducts is not exceeded the allowed limit, so it will not cause a direct risk to health.

  11. 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

  12. 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.

    2017-12-01

    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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. STS-56 inflight maintenance (IFM) air duct routing on OV-103's middeck

    Science.gov (United States)

    1993-01-01

    STS-56 inflight maintenance (IFM) repair on Discovery's, Orbiter Vehicle (OV) 103's, middeck was required to offset overheating problems with one of the onboard experiments -- Detailed Supplementary Objective (DSO) 322, Human lymphocyte locomotion in microgravity. This 'elephant's trunk' fix was rigged from the airlock's air recirculation duct to DSO 322's forward locker location by Commander Kenneth Cameron. The 'elephant's trunk' was fashioned from trash bags and other plastic items to extend an airline to the troubled area. DSO 322 is collecting data on the locomotion and migration of human lymphocytes through intercellular matrix and is testing the rotating wall vessel and the specimen temperature controller. In the background is the port side wall with the side hatch, middeck accomodations rack (MAR), and shuttle orbiter repackaged galley (SORG) visible.

  19. 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.

  20. 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.

  1. 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.

  2. Sound transmission loss of double plates with an air cavity between them in a rigid duct.

    Science.gov (United States)

    Kim, Hyun-Sil; Kim, Sang-Ryul; Lee, Seong-Hyun; Seo, Yun-Ho; Ma, Pyung-Sik

    2016-05-01

    In this paper, the sound transmission loss (STL) of thin double plates with an air cavity between them in a rigid duct is considered using an analytical approach. The vibration motion of the plate and sound pressure field are expanded in terms of an infinite series of the modal functions. Under the plane wave condition, a low frequency solution is derived by including the first few symmetric modes. It is determined that the peak frequencies of the double plates coincide with those of each single plate. When the two plates are identical, the STL becomes zero at the natural frequencies of the single plate. However, when the two plates are not identical, the STL is always greater than zero. The location and amplitude of the dips are investigated using an approximate solution when the cavity depth is very small. It is observed that dividing the single plate into two plates with an air cavity in between degrades the STL in the low frequency range, while the equivalent surface mass density is preserved. However, when the cavity depth is not small, the STL of the single plate can be smaller than that of the double plates.

  3. 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.

  4. 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.

  5. Heater assembly

    International Nuclear Information System (INIS)

    Lee, K.; Ueng, Tzoushin.

    1991-01-01

    An electrical resistance heater, installed in the H1 borehole, is used to thermally perturb the rock mass through a controlled heating and cooling cycle. Heater power levels are controlled by a Variac power transformer and are measured by wattmeters. Temperatures are measured by thermocouples on the borehole wall and on the heater assembly. Power and temperature values are recorded by the DAS described in Chapter 12. The heater assembly consists of a 3.55-m (11.6-ft) long by 20.3-cm (8-in.) O.D., Type 304 stainless steel pipe, containing a tubular hairpin heating element. The element has a heated length of 3 m (9.84 ft). The power rating of the element is 10 kW; however, we plan to operate the unit at a maximum power of only 3 kW. The heater is positioned with its midpoint directly below the axis of the P2 borehole, as shown in the borehole configuration diagram. This heater midpoint position corresponds to a distance of approximately 8.5 m (27.9 ft) from the H1 borehole collar. A schematic of the heater assembly in the borehole is shown. The distance from the borehole collar to the closest point on the assembly (the front end) is 6.5 m (21.3 ft). A high-temperature inflatable packer, used to seal the borehole for moisture collection, is positioned 50 cm (19.7 in.) ahead of the heater front end. The heater is supported and centralized within the borehole by two skids, fabricated from 25-mm (1-in.) O.D. stainless steel pipe. Thermocouples are installed at a number of locations in the H1 borehole. Four thermocouples that are attached to the heater skin monitor temperatures on the outer surface of the can, while three thermocouples that are held in place by rock sections monitor borehole wall temperatures beneath the heater. Temperatures are also monitored at the heater terminal and on the packer hardware

  6. Transmission of Mycobacterium chimaera from Heater-Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System.

    Science.gov (United States)

    Sommerstein, Rami; Rüegg, Christian; Kohler, Philipp; Bloemberg, Guido; Kuster, Stefan P; Sax, Hugo

    2016-06-01

    Heater-cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices.

  7. 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.

  8. The Influence of Cooling Air Injection on Flow Development and Heat Transfer in a Rotating Leading Edge Coolant Duct of a Film-Cooled Turbine Blade

    National Research Council Canada - National Science Library

    Elfert, Martin

    2003-01-01

    .... This paper provides information about rotational effects on fluid motion and heat transfer within a rotating coolant duct of circular cross section with bleeding of cooling air through a row of film...

  9. 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.

  10. 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...

  11. 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...

  12. Solar air heaters for industrial drying; Aquecedor solar de ar para secagem industrial

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Everaldo Mendes [Governo do Estado da Paraiba, Joao Pessoa, PB (Brazil). Secretaria de Planejamento e Gestao

    2008-07-01

    The objective of this study is to encourage the use of solar energy in industrial drying of fruits, with the producers poles, at the same time, promote the rational use of energy for heat, or replacing the hydroelectric and oil derivatives for this purpose. This study is presented in the following chapters: availability of solar energy; details of constructive solar heated air; drying fruit; market. (author)

  13. FIELD EVALUATION OF IMPROVED METHODS FOR MEASURING THE AIR LEAKAGE OF DUCT SYSTEMS UNDER NORMAL OPERATING CONDITIONS IN 51 HOMES

    Energy Technology Data Exchange (ETDEWEB)

    Paul W. Francisco; Larry Palmiter; Erin Kruse; Bob Davis

    2003-10-18

    Duct leakage in forced-air distribution systems has been recognized for years as a major source of energy losses in residential buildings. Unfortunately, the distribution of leakage across homes is far from uniform, and measuring duct leakage under normal operating conditions has proven to be difficult. Recently, two new methods for estimating duct leakage at normal operating conditions have been devised. These are called the nulling test and the Delta-Q test. Small exploratory studies have been done to evaluate these tests, but previously no large-scale study on a broad variety of homes has been performed to determine the accuracy of these new methods in the field against an independent benchmark of leakage. This sort of study is important because it is difficult in a laboratory setting to replicate the range of leakage types found in real homes. This report presents the results of a study on 51 homes to evaluate these new methods relative to an independent benchmark and a method that is currently used. An evaluation of the benchmark procedure found that it worked very well for supply-side leakage measurements, but not as well on the return side. The nulling test was found to perform well, as long as wind effects were minimal. Unfortunately, the time and difficulty of setup can be prohibitive, and it is likely that this method will not be practical for general use by contractors except in homes with no return ducts. The Delta-Q test was found to have a bias resulting in overprediction of the leakage, which qualitatively confirms the results of previous laboratory, simulation, and small-scale field studies. On average the bias was only a few percent of the air handler flow, but in about 20% of the homes the bias was large. A primary flaw with the Delta-Q test is the assumption that the pressure between the ducts and the house remain constant during the test, as this assumption does not hold true. Various modifications to the Delta-Q method were evaluated as

  14. RESULTS OF INVESTIGATIONS ON THERMAL CHARACTERISTICS OF AIR HEATER BUNDLE MADE OF BIMETALLIC FINNED TUBES

    Directory of Open Access Journals (Sweden)

    V. B. Kuntysh

    2014-01-01

    Full Text Available The paper presents a scheme and description of a new aerodynamic stand that has a 300x300 mm cross-section operating channel. The stand is used for studying thermal and aerodynamic characteristics of bundles made of finned tubes of actual dimensions in crossflow. The paper provides results of an exploratory test pertaining to heat transfer and resistance of four row staggered bundle made of tubes with aluminium spiral fins having outside diameter of 26 mm which are used in the systems of ventilation, air-conditioning and heating of buildings and also in transport heat exchangers.

  15. New type of thermal analyzer with a micro-air-bridge heater

    Science.gov (United States)

    Kimura, Mitsuteru; Hayasaka, Junichi

    1997-11-01

    Miniaturized sensor for thermal analysis is fabricated using micromachining technique and its fundament al characteristics are obtained. This device fabricated in a Si substrate consists of monolithically integrated components of an air-bridge type microheater, a thin film thermocouple and a sample-holder. Boiling points of liquid samples, water and methanol, are observed in the heating curve and the heating-rate curve, and sudden decrease of the temperature at the dropping time of the liquid samples at room temperature due to the effect of evaporation heat is also observed. Loss of the sample due to the evaporation during heating was theoretically discussed.

  16. 46 CFR 116.610 - Ventilation ducts.

    Science.gov (United States)

    2010-10-01

    ... served by the ventilation duct for shutting off the passage of air through the ventilation duct in the... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation ducts. 116.610 Section 116.610 Shipping... Ventilation § 116.610 Ventilation ducts. (a) For the purposes of this section, a ventilation duct includes any...

  17. 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.

  18. Ignition of lean fuel-air mixtures in a premixing-prevaporizing duct at temperatures up to 1000 K

    Science.gov (United States)

    Tacina, R. R.

    1980-01-01

    Conditions were determined in a premixing prevaporizing fuel preparation duct at which ignition occurred. An air blast type fuel injector with nineteen fuel injection points was used to provide a uniform spatial fuel air mixture. The range of inlet conditions where ignition occurred were: inlet air temperatures of 600 to 1000 K air pressures of 180 to 660 kPa, equivalence ratios (fuel air ratio divided by stoichiometric fuel air ratio) from 0.12 to 1.05, and velocities from 3.5 to 30 m/s. The duct was insulated and the diameter was 12 cm. Mixing lengths were varied from 16.5 to 47.6 and residence times ranged from 4.6 to 107 ms. The fuel was no. 2 diesel. Results show a strong effect of equivalence ratio, pressure and temperature on the conditions where ignition occurred. The data did not fit the most commonly used model of auto-ignition. A correlation of the conditions where ignition would occur which apply to this test apparatus over the conditions tested is (p/V) phi to the 1.3 power = 0.62 e to the 2804/T power where p is the pressure in kPa, V is the velocity in m/e, phi is the equivalence ratio, and T is the temperature in K. The data scatter was considerable, varying by a maximum value of 5 at a given temperature and equivalence ratio. There was wide spread in the autoignition data contained in the references.

  19. Ultraviolet germicidal irradiation inactivation of airborne fungal spores and bacteria in upper-room air and HVAC in-duct configurations

    Energy Technology Data Exchange (ETDEWEB)

    Kujundzic, E.; Hernandez, M. [Colorado Univ., Boulder, CO (United States). Dept. of Civil, Environmental and Architectural Engineering; Miller, S.L. [Colorado Univ., Boulder, CO (United States). Dept. of Mechanical Engineering

    2007-01-15

    This article presented an evaluation of the efficiency of ultraviolet germicidal irradiation (UVGI) for inactivating airborne fungal spores and bacterial vegetative cells under 3 configurations, namely intrinsic, upper-room air, and in-duct. Several experiments were conducted in a pilot-scale chamber fitted with 4 corner ultraviolet lamps that irradiated the entire chamber; a full-scale room fitted with a UVGI system that irradiated the top 30 cm of the room; and, the supply air duct of a heating ventilation and air-conditioning (HVAC) system. Fungal spores and vegetative cells of bacterium were aerosolized regularly such that their numbers and physiologic state were comparable both with and without the UVGI lamps operating. The article provided information on the materials and methods used including the experimental facilities (pilot-scale chamber, full-scale room, and in-duct UVGI system and ductwork) as well as the methods used for the three experimental studies. It also discussed the bioaerosol generation and sampling and quantification. These included culturing and direct microscopy. UV fluence rate was described. Last, the the results, discussion and conclusions from the studies were presented. It was shown that increasing the air stream velocity through the supply air duct reduces the residence time of bioaerosol being exposed to in-duct UVGI. 36 refs., 3 figs.

  20. Convective heater

    Science.gov (United States)

    Thorogood, Robert M.

    1983-01-01

    A convective heater for heating fluids such as a coal slurry is constructed of a tube circuit arrangement which obtains an optimum temperature distribution to give a relatively constant slurry film temperature. The heater is constructed to divide the heating gas flow into two equal paths and the tube circuit for the slurry is arranged to provide a mixed flow configuration whereby the slurry passes through the two heating gas paths in successive co-current, counter-current and co-current flow relative to the heating gas flow. This arrangement permits the utilization of minimum surface area for a given maximum film temperature of the slurry consistent with the prevention of coke formation.

  1. Heat-transfer coefficients for air flowing in round tubes, in rectangular ducts, and around finned cylinders

    Science.gov (United States)

    Drexel, Rober E; Mcadams, William H

    1945-01-01

    Report reviews published data and presents some new data on heat transfer to air flowing in round tubes, in rectangular ducts, and around finned cylinders. The available data for heat transfer to air in straight ducts of rectangular and circular cross section have been correlated in plots of Stanton number versus Reynolds number to provide a background for the study of the data for finned cylinders. Equations are recommended for both the streamlined and turbulent regions, and data are presented for the transition region between turbulent and laminar flow. Use of hexagonal ends on round tubes causes the characteristics of laminar flow to extend to high Reynolds numbers. Average coefficients for the entire finned cylinder have been calculated from the average temperature at the base of the fins and an equation which was derived to allow for the effectiveness of the fins. The available results for each finned cylinder are correlated herein in terms of graphs of Stanton number versus Reynolds number. In general, for a given Reynolds number, the Stanton number increases with increases in both spacing and width of the fins, and is apparently independent of cylinder diameter and temperature difference. For a given coefficient of heat transfer improved baffles and rough or wavy surfaces give a substantial reduction in pumping power per unit of heat transfer surface and a somewhat smaller decrease in pressure drop. (author)

  2. 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.

  3. 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.

  4. Studi Numerik Karakteristik Pengeringan Batubara pada Fluidized Bed Coal Dyer Terhadap Pengaruh Variasi Temperatur Air Heater dengan Tube Heater Tersusun Staggered dan Perbandingan Volume Chamber dan Volume Batubara Sebesar 50%

    Directory of Open Access Journals (Sweden)

    Ayu Sarah Novrizqa

    2013-03-01

    Full Text Available Indonesia mempunyai sumber daya batubara yang cukup besar dan sebagian besar sumber daya tersebut termasuk ke dalam batubara peringkat rendah berupa lignit dan sub-bituminus yang memiliki kadar air yang tinggi. Tingginya kadar air menyebabkan rendahnya nilai kalor, sehingga pemanfaatan batubara jenis ini menjadi terbatas dan sulit untuk dipasarkan. Oleh karena itu perlu adanya teknologi pengeringan yang dapat meningkatkan nilai kalor dari batubara tersebut. Dalam proses pengeringan akan melibatkan perpindahan panas dan massa. Proses ini akan didefinisikan dalam suatu studi numerik, dimana penelitian ini dilakukan dengan metode numerik dengan software Fluent 6.3.26. Pemilihan kondisi simulasi digunakan model turbulensi k-ε realizable dan skema interpolasi first-order upwind. Serta mempelajari pengaruh temperatur inlet udara pengering yang divariasikan. Variasi temperatur adalah 316 K, 327 K, 339 K. Dari penelitian ini  dapat diketahui nilai drying rate serta pengaruh temperatur dan posisi batubara dalam proses pengeringan pada drying chamber fluidized bed coal dryer dengan tube heater tersusun staggered serta pengaruh dari perbandingan volume batubara dengan volume chamber sebesar 50%. Moisture content batubara yang paling banyak berkurang dialami oleh temperature outlet terbesar yaitu 339 K dari 0,22 hingga 0,0167. Laju pengeringan yang memiliki waktu paling cepat yaitu pada temperatur 339 K, sekitar 1100 detik, sedangkan yang memiliki waktu paling lama yaitu pada temperatur 316 K, sekitar 4600 detik.

  5. 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

  6. 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.)

  7. 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.

  8. 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

  9. Wind-Tunnel Tests of a 1/6-Scale Model of Republic XF-12 Vertical Tail Incorporating a De-Icing Air Duct

    Science.gov (United States)

    MacLachlan, Robert; Miller, Sadie M.

    1945-01-01

    A 1/6-scale model of the Republic XF-12 vertical tail with stub fuselage, stub horizontal tail, and a de-icing air duct was tested in the Langley stability tunnel. The investigation consisted of a study of the effects of the duct, with and without air flow, on the aerodynamic characteristics of the model. The model tested was a revision of a model previously tested in the Langley stability tunnel. The revised model differed from the original model in that it incorporated a de-icing air duct, included a dorsal fin, and had a larger stub fuselage. A comparison of data obtained form tests of the original and revised models was made. The results of the investigation indicated that the air duct had very little effect on the aerodynamic characteristics of the model. A small change occurred in the variation of rudder hinge-moment coefficient with angle of attack but it is believed that this change can be corrected by a properly applied spring tab.

  10. 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.

  11. 14 CFR 25.859 - Combustion heater fire protection.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Combustion heater fire protection. 25.859....859 Combustion heater fire protection. (a) Combustion heater fire zones. The following combustion... surrounds the combustion chamber. However, no fire extinguishment is required in cabin ventilating air...

  12. 14 CFR 29.859 - Combustion heater fire protection.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Combustion heater fire protection. 29.859... § 29.859 Combustion heater fire protection. (a) Combustion heater fire zones. The following combustion... any ventilating air passage that— (i) Surrounds the combustion chamber; and (ii) Would not contain...

  13. 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

  14. 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)

  15. Study of Air Ingress Across the Duct During the Accident Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Yassin [Texas A & M Univ., College Station, TX (United States)

    2013-05-06

    The goal of this project is to study the fundamental physical phenomena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a rupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefore, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that minimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlying phenomena. The combination of inter-diffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. This project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses; and, Perform computational fluid dynamics analysis of air ingress phenomena.

  16. 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.

  17. FRACTIONAL AEROSOL FILTRATION EFFICIENCY OF IN-DUCT VENTILATION AIR CLEANERS

    Science.gov (United States)

    The filtration efficiency of ventilation air cleaners is highly particle-size dependent over the 0.01 to 3 μm diameter size range. Current standardized test methods, which determine only overall efficiencies for ambient aerosol or other test aerosols, provide data of limited util...

  18. 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)

  19. 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

  20. Cleanliness of ventilation ducts, indoor space and AHU

    OpenAIRE

    Rubina, Aleš; Rubinová, Olga; Blasinski, Petr

    2015-01-01

    Paper deals with analysis of cleanliness air conditioning duct for various stages of construction. There were taken samples and these were analyzed for different type of storage duct on construction. They are compared differences between the "right" stored duct and unprotected duct including the actual interior space and air handling units serving. In the conclusion of this article is summarized the impact of carryover dirt from the duct and an air handling unit to the ventilation s...

  1. 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.

  2. New Design Heaters Using Tubes Finned by Deforming Cutting Method

    Science.gov (United States)

    Zubkov, N. N.; Nikitenko, S. M.; Nikitenko, M. S.

    2017-10-01

    The article describes the results of research aimed at selecting and assigning technological processing parameters for obtaining outer fins of heat-exchange tubes by the deformational cutting method, for use in a new design of industrial water-air heaters. The thermohydraulic results of comparative engineering tests of new and standard design air-heaters are presented.

  3. 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.

  4. Experimental evaluation on the use of capillary tube and thermostatic expansion valve with heat recovery hot spot water heater in air source refrigeration system

    Science.gov (United States)

    Aziz, Azridjal; Mainil, Rahmat Iman; Mainil, Afdhal Kurniawan; Saputra, Eko

    2017-01-01

    The present experimental evaluation has been carried out to investigate the use of capillary tube (CT) and thermostatic expansion valve (TEV) with heat recovery hot spot water heater (HRHSWH) in air source compression refrigeration system. CT and TEV are the two basic types of refrigerant expansion devices that most frequently used in compression refrigeration system, but the identified about HRHSWH in extant literature are limited. The HRHSWH is modified from residential refrigeration system. The heat exchanger coil as HRHSWH was bonded with the compressor discharge pipe line as counter-flow heat exchanger, then insulated and placed them into transparent acrylic box. Water from storage tank with 50L capacity is pumped using circulation pump to the HRHSWH and heating the water in storage tank. The system performance of those two expansion devices in compression refrigeration system are evaluated and compared between with or without modified using HRHSWH. Results show that refrigeration system using TEV performs better performance than CT using HRHSWH compared to standard refrigeration system (without HRHSWH). The use of TEV device in HRHSWH causes a slight decrease in compressor power 0.0198 kW (4%), where the COP increases around 20% higher than the CT device. The finding indicates that the use of HRHSWH generates free hot water for TEV and CT with temperature around 54.06°C and 55.78°C, respectively. In general, HRHSWH give better perfomance than standar refrigeration system.

  5. The estimation of Helmholtz resonator and active noise control to predict noise reduction of fan in an air duct

    Directory of Open Access Journals (Sweden)

    Farhad Forouharmajd

    2015-01-01

    Full Text Available Aims: The main goal of this paper was to evaluate the effectiveness of Helmholtz resonator in noise reduction of duct equipped with active noise control (ANC. Materials and Methods: Noise frequency band was produced by a propeller fan, which was spread into a plexiglas duct. The noise was formed by digital signal processing (DSP to estimate the anti-noise which spreads along the duct to postpone the primary noise as a response to DSP. In this method, fan noise was recorded with a microphone. The anti-noise with the same amplitude was reproduced, and the reverse phase postpones the original noise at the primary noise path by a speaker. The designed Helmholtz resonator was installed on the duct for detecting the reduction noise at the tonal interest frequency of 300 Hz. Helmholtz resonators can give sound attenuation at a narrowband of frequencies, close to its resonance frequency. The overall decline changes were estimated in order to predict the effectiveness of the method. Results: In this study, a noise discount of 5-10 dB at the peak frequencies has been observed. The peak frequency of residual noise has reduced 5-10 dB. The value is more than applying ANC system solely to optimize noise lessening of produced noise by a fan along the designed duct. Conclusion: Use of Helmholtz resonator is proposed as a suggestion to optimize the process of noise fall in duct. This study is concerned with the attenuation of tonal noise transmission in ducts by using ANC and side branch resonators together.

  6. Method and apparatus for duct sealing using a clog-resistant insertable injector

    Science.gov (United States)

    Wang, Duo; Modera, Mark P.

    2010-12-14

    A method for forming a duct access region through one side of a previously installed air duct, wherein the air duct has an air flow with an air flow direction by inserting an aerosol injector into a previously installed air duct through the access region. The aerosol injector includes a liquid tube having a liquid tube orifice for ejecting a liquid to be atomized; and a propellant cap. The method is accomplished by aligning the aerosol injector with the direction of air flow in the duct; activating an air flow within the duct; and spraying a sealant through the aerosol injector to seal the duct in the direction of the air flow.

  7. 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

  8. Linear concentrating collector as an air heater in the heating system of building in Polish climatic conditions

    Directory of Open Access Journals (Sweden)

    Nemś Magdalena

    2016-01-01

    Full Text Available The article presents the analysis of the performance of a concentrating collector in the heating system of a residential building. Air was used as the working fluid. The heating requirements of the building were determined for each day of the year. The amount of direct irradiation reaching the absorber’s surface on all the days of the year was determined with the use of hourly meteorological data for Wroclaw, shared by the Ministry of Infrastructure and Growth. It was assumed that the collector is equipped with a tracking system working in one axis. Calculations and comparisons were made for the amount of solar irradiation for three values of the receiver’s inclination angle: β1=60°, β2=90° and β3=30°. Statistical method was used in order to determine the optimum inclination of the mirror and the amount of flowing air. This method involves creating a plan of experiment with three levels of changeability for two input factors. In the last stage, the amount of heat obtained from the installation during all the days of the year was analysed. The gains were juxtaposed on the diagram with the building’s heat demand. The analysis has shown that the heat requirements can be met only partially.

  9. Autoignition in a premixing-prevaporizing fuel duct using 3 different fuel injection systems at inlet air temperatures to 1250 K

    Science.gov (United States)

    Tacina, R. R.

    1983-01-01

    Conditions were determined in a continuous-flow, premixing-prevaporizing duct at which autoignition occurred. Test conditions were representative of an advanced, regenerative-cycle, automotive gas turbine. The test conditions inlet air temperatures from 600 to 1250 K (a vitiated preheater was used), pressures from 170 to 600 kPa, air velocities of 10 to 30 m/sec, equivalence ratios from 0.3 to 1.0, mixing lengths from 10 to 60 cm, and residence times of 2 to 100 ms. The fuel was diesel number 2. The duct was insulated and had an inside diameter of 12 cm. Three different fuel injection systems were used: One was a single simplex pressure atomizer, and the other two were multiple-source injectors. The data obtained with the simplex and one of the multiple-source injectors agreed satisfactorily with the references and correlated with an Arrenhius expression. The data obtained with the other multiple source injector, which used multiple cones to improve the fuel-air distribution, did not correlate well with residence time.

  10. The benefits of whole-house in-duct air cleaning in reducing exposures to fine particulate matter of outdoor origin: a modeling analysis.

    Science.gov (United States)

    Macintosh, David L; Minegishi, Taeko; Kaufman, Matthew; Baker, Brian J; Allen, Joseph G; Levy, Jonathan I; Myatt, Theodore A

    2010-03-01

    Health risks of fine particle air pollution (PM(2.5)) are an important public health concern that has the potential to be mitigated in part by interventions such as air cleaning devices that reduce personal exposure to ambient PM(2.5). To characterize exposure to ambient PM(2.5) indoors as a function of residential air cleaners, a multi-zone indoor air quality model was used to integrate spatially resolved data on housing, meteorology, and ambient PM(2.5), with performance testing of residential air cleaners to estimate short-term and annual average PM(2.5) of outdoor origin inside residences of three metropolitan areas. The associated public health impacts of reduced ambient PM(2.5) exposure were estimated using a standard health impact assessment methodology. Estimated indoor levels of ambient PM(2.5) varied substantially among ventilation and air cleaning configurations. The median 24-h average indoor-outdoor ratio of ambient PM(2.5) was 0.57 for homes with natural ventilation, 0.35 for homes with central air conditioning (AC) with conventional filtration, and 0.1 for homes with central AC with high efficiency in-duct air cleaner. Median modeled 24-h average indoor concentrations of PM(2.5) of outdoor origin for those three configurations were 8.4, 5.3, and 1.5 microg/m(3), respectively. The potential public health benefits of reduced exposure to ambient PM(2.5) afforded by air cleaning systems were substantial. If the entire population of single-family homes with central AC in the modeling domain converted from conventional filtration to high-efficiency in-duct air cleaning, the change in ambient PM(2.5) exposure is estimated to result in an annual reduction of 700 premature deaths, 940 hospital and emergency room visits, and 130,000 asthma attacks in these metropolitan areas. In addition to controlling emissions from sources, high-efficiency whole-house air cleaner are expected to reduce exposure to particles of outdoor origin and are projected to be an

  11. Performance investigation of a novel frost-free air-source heat pump water heater combined with energy storage and dehumidification

    International Nuclear Information System (INIS)

    Wang, Fenghao; Wang, Zhihua; Zheng, Yuxin; Lin, Zhang; Hao, Pengfei; Huan, Chao; Wang, Tian

    2015-01-01

    Highlights: • Experiments are carried out to investigate a novel frost-free ASHPWH system. • Dynamic characteristics of the system are studied at different ambient conditions. • Test results confirm the expected potential to control the frost-free process. • The COP increased 17.9% and 3.4% respectively in comparison with RCD at −3 °C and 3 °C. - Abstract: Air-source heat pump (ASHP) often operates with substantial frost formation on the outdoor heat exchanger at low ambient temperature in winter, it insulates the finned surface and also reduces heat transfer rate, leading to performance degradation or even shutdown of ASHP systems. Although several defrosting methods have been reported, the frosting and defrosting processes reduced energy efficiency and resulted in, in some cases, heat pump breakdown. To solve this problem, a novel frost-free air-source heat pump water heater (ASHPWH) system has been developed, which coupled with an extra heat exchanger coated by a solid desiccant (EHECSD) with an energy storage device (ESD). Based on the previous studies, a further analysis and comprehensive research on the novel frost-free ASHPWH system is presented in this paper. The dynamic characteristics of the novel system are investigated experimentally in different ambient conditions. An experimental setup and experimental procedures are described in detail. Thereafter, the dehumidification efficiency and regeneration efficiency of EHECSD, suction and discharge pressures of the compressor, the temperature of PCM are evaluated during the heating and regeneration modes respectively. Results indicate that the system can keep the evaporator frost-free for 32, 34, 36 min during heating mode at the ambient temperatures of −3 °C, 0 °C and 3 °C and 85% RH. Compared with the reverse-cycle defrosting (RCD), COP of the frost-free ASHPWH are 17.9% and 3.4% higher at the ambient temperature of −3 °C and 3 °C respectively. With this innovative technology, it has

  12. Air-filled left hepatic duct: the saber sign as an aid to the radiographic diagnosis of pneumobilia

    International Nuclear Information System (INIS)

    Lewandowski, B.J.; Withers, C.; Winsberg, F.

    1984-01-01

    In the supine patient, gas rises to the left hepatic duct. Radiographically, this can be recognized as a saber-shaped lucency to the right of the spine. In a retrospective analysis and review of the radiographs of 40 patients shown to have gas in the biliary tree by ultrasound (US), computed tomography (CT), or radiography, the diagnosis could be made in 37 patients. In 18 of these 37 cases pneumobilia could be identified by the saber-shaped distribution of gas

  13. Duct injection for SO{sub 2} control, Design Handbook, Volume 1, Process design and engineering guidelines

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    PETC developed a comprehensive program of coal-related, acid-rain research and development with a major activity area centering on flue gas cleanup and control of SO{sub 2} emissions. Particular emphasis was placed on the retrofit measures for older coal-fired power plants which predate the 1971 New Source Performance Standards. Candidate emission control technologies fall into three categories, depending upon their point of application along the fuel path (i.e., pre, during, or post combustion). The post-combustion, in-duct injection of a calcium-based chemical reagent seemed promising. Preliminary studies showed that reagent injection between the existing air heater and electrostatic precipitator (ESP) could remove between 50-60% of the SO{sub 2} and produce an environmentally safe, dry, solid waste that is easily disposed. Although SO{sub 2} removal efficiencies were less, the estimated capital costs for duct injection technology were low making the economics of duct injection systems seem favorable when compared to conventional wet slurry scrubbers under certain circumstances. With the promulgation of the Clean Air Act Amendments of 1990 came more incentive for the development of low capital cost flue gas desulfurization (FGD) processes. A number of technical problems had to be resolved, however, before duct injection technology could be brought to a state of commercial readiness. The Duct Injection Technology Development Program was launched as a comprehensive, four-year research effort undertaken by PETC to develop this new technology. Completed in 1992, this Duct Injection Design Handbook and the three-dimensional predictive mathematical model constitute two primary end products from this development program. The aim of this design handbook and the accompanying math model is to provide utility personnel with sufficient information to evaluate duct injection technology against competing SO{sub 2} emissions reduction strategies for an existing plant.

  14. Investigation Flow Uniformity in a Supersonic Duct with High Enthalpy Flows

    Science.gov (United States)

    Balboni, John; Atler, Doug; Gokcen, Tahir; Hartman, G. Joseph (Technical Monitor)

    1995-01-01

    Flow uniformity in a high enthalpy facility is investigated. The scramjet research facility is composed of a rectangular combustor duct connected to a 100 MW electric arc air heater. The Mach 3.3 flow is accelerated through a two-dimensional contoured nozzle. Instream measurements were made with water-cooled Pitot probes and stagnation point heat flux gages at stream enthalpy levels ranging from 4 to 7 Mj/kg. Flow surveys were made on the flow centerline and off centerline in order to measure the three dimensional uniformity of the flow in the rectangular duct. Measurements indicated that although the flow in the aspect ratio 6:1 duct was relatively uniform on the centerline, three dimensional viscous effects were apparent near the corners. Flow through the nozzle and constant area duct was modeled computationally using a two dimensional, Navier-Stokes, reacting gas code. The computations predict that the flow in the test section is in vibrational equilibrium. The computed and measured Pitot pressure and heat flux profiles are in reasonable agreement with the experimental data.

  15. 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.

  16. Explosives tester with heater

    Science.gov (United States)

    Del Eckels, Joel [Livermore, CA; Nunes, Peter J [Danville, CA; Simpson, Randall L [Livermore, CA; Whipple, Richard E [Livermore, CA; Carter, J Chance [Livermore, CA; Reynolds, John G [San Ramon, CA

    2010-08-10

    An inspection tester system for testing for explosives. The tester includes a body and a swab unit adapted to be removeably connected to the body. At least one reagent holder and dispenser is operatively connected to the body. The reagent holder and dispenser contains an explosives detecting reagent and is positioned to deliver the explosives detecting reagent to the swab unit. A heater is operatively connected to the body and the swab unit is adapted to be operatively connected to the heater.

  17. Aerodynamic Design and Analysis of Propellers for Mini-Remotely Piloted Air Vehicles. Volume 2. Ducted Propellers

    Science.gov (United States)

    1978-05-01

    110 28t UT__n M t : X . (.4 u~..4 I 1: H 1 1I 1C . Al 0 -fUS~PD IM’ T! I I t-n!2n I 0 0 00N 0 n 0 r%~ 00 SON lca . LMNn L 0 M Nm 0nL 300 DUCTED...PROPELLERS The existing RPV’s incorporate shrouds to protect the propeller from damage and operating personnel from injury . The shrouds used are not

  18. 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.

  19. 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)

  20. Note: Improved heater design for high-temperature hollow cathodes.

    Science.gov (United States)

    McDonald, M S; Gallimore, A D; Goebel, D M

    2017-02-01

    We present an improved heater design for thermionic cathodes using a rhenium filament encased in a boron nitride ceramic sleeve. This heater is relatively simple to fabricate, yet has been successfully used to reliably and repeatably light a lanthanum hexaboride (LaB6) hollow cathode based on a previously published design without noticeable filament degradation over hundreds of hours of operation. The high decomposition temperature of boron nitride (2800 C for inert environments) and melting point for rhenium (3180 C) make this heater especially attractive for use with LaB6, which may require operating temperatures upwards of 1700 C. While boron nitride decomposes in air above 1000 C, the heater was used only at vacuum with an inert gas discharge, and no degradation was observed. Limitations of current state of the art cathode heaters are also discussed and compared with the rhenium-boron nitride combination.

  1. “This is not a burning issue for me”: How citizens justify their use of wood heaters in a city with a severe air pollution problem

    International Nuclear Information System (INIS)

    Reeve, Ian; Scott, John; Hine, Donald W.; Bhullar, Navjot

    2013-01-01

    Although wood smoke pollution has been linked to health problems, wood burning remains a popular form of domestic heating in many countries across the world. In this paper, we describe the rhetoric of resistance to wood heater regulation amongst citizens in the regional Australian town of Armidale, where wood smoke levels regularly exceed national health advisory limits. We discuss how this is related to particular sources of resistance, such as affective attachment to wood heating and socio-cultural norms. The research draws on six focus groups with participants from households with and without wood heating. With reference to practice theory, we argue that citizen discourses favouring wood burning draw upon a rich suite of justifications and present this activity as a natural and traditional activity promoting comfort and cohesion. Such discourses also emphasise the identity of the town as a rural community and the supposed gemeinschaft qualities of such places. We show that, in this domain of energy policy, it is not enough to present ‘facts’ which have little emotional association or meaning for the populace. Rather, we need understand how social scripts, often localised, inform identity and practice. - Highlights: ► The negative health effects of wood smoke from wood heaters are known by citizens. ► Continued use of wood heating is justified with a rich suite of rhetorical strategies. ► Some strategies try to negate or diminish the case for phasing out wood heaters. ► Other strategies present wood heating as a natural, traditional and social activity

  2. An Investigation of Aircraft Heaters. 11 - Measured and Predicted Performance of a Slotted-Fin Exhaust Gas and Air Heat Exchanger

    Science.gov (United States)

    1943-04-01

    the heater. “.This result was br~ught abGut b~tli”by docreasin~~the not .cr~ss-secti~nnl arom of fl~w nnd by forcinp tho gas ta flow through the...exhaust gaa is-cooled. The laet term in . equation (11) is negative for the case of a fluld being cooled and ig les ~ negative at high fluld rates, for...transferi T! le use of:~he team , tral cord, ‘hcwevoz, forced the exhaust gee to flow. alorig the slotted fins and, together with the inprease in

  3. INTERIOR DUCT SYSTEM DESIGN, CONSTRUCTION, AND PERFORMANCE

    Energy Technology Data Exchange (ETDEWEB)

    Janet E.R. Mcllvaine; David Beal; Philip Fairey

    2001-10-10

    By removing air distribution and conditioning equipment from unconditioned spaces, homeowners stand to benefit substantially with respect to both energy savings and indoor air quality. Duct leakage introduces: Greater heating and cooling loads from air at extreme temperatures and humidity levels; Outside air and air from unconditioned spaces that may contain air borne contaminants, combustion gases, pollen, mold spores, and/or particles of building materials; and Higher whole-house infiltration/exfiltration rates. Exemplary studies conducted since 1990 have demonstrated the prevalence of duct leakage throughout the United States and measured energy savings of approximately 20% during both heating and cooling seasons from leakage reduction. These all dealt with duct leakage to and/or from unconditioned spaces. In the building science community, leakage within the conditioned space is generally presumed to eliminate the negative consequences of duct leakage with the exception of possibly creating pressure imbalances in the house which relates to higher infiltration and/or exfiltration. The practical challenges of isolating ducts and air handlers from unconditioned spaces require builders to construct an air-tight environment for the ducts. Florida Solar Energy Center researchers worked with four builders in Texas, North Carolina, and Florida who build a furred-down chase located either in a central hallway or at the edges of rooms as an architectural detail. Some comparison homes with duct systems in attics and crawl spaces were included in the test group of more than 20 homes. Test data reveals that all of the duct/AHU systems built inside the conditioned space had lower duct leakage to unconditioned spaces than their conventional counterparts; however, none of the homes was completely free of duct leakage to unconditioned spaces. Common problems included wiring and plumbing penetrations of the chase, failure to treat the chase as an air tight space, and misguided

  4. High Efficiency, Ultra-Low Emission, Integrated Process Heater System

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Howard; Boral, Anindya; Chhotray, San; Martin, Matthew

    2006-06-19

    The team of TIAX LLC, ExxonMobil Research and Engineering Company, and Callidus Technologies, LLC conducted a six-year program to develop an ultra-low emission process heater burner and an advanced high efficiency heater design. This project addresses the critical need of process heater operators for reliable, economical emission reduction technologies to comply with stringent emission regulations, and for heater design alternatives that reduce process heater energy requirements without significant cost increase. The key project targets were NOx emissions of 10 ppm (@ 3% O2), and a heater thermal efficiency of 95 percent. The ultra low NOx burner was developed through a series of pilot-scale and field tests combined with computational fluid dynamic modeling to arrive at simultaneous low emissions and suitable flame shape and stability. Pilot scale tests were run at TIAX, at the 2 MMBtu/hr scale, and at Callidus at 8 MMBtu/hr. The full scale burner was installed on a 14 burner atmospheric pipestill furnace at an ExxonMobil refinery. A variety of burner configurations, gas tips and flame stabilizers were tested to determine the lowest emissions with acceptable flame shape and stability. The resulting NOx emissions were 22 ppm on average. Starting in 2001, Callidus commercialized the original ultra low NOx burner and made subsequent design improvements in a series of commercial burners evolving from the original concept and/or development. Emissions in the field with the ultra low-NOx burner over a broad spectrum of heater applications have varied from 5 ppm to 30 ppm depending on heater geometry, heater service, fuel and firing capacity. To date, 1550 of the original burners, and 2500 of subsequent generation burners have been sold by Callidus. The advanced heater design was developed by parametric evaluations of a variety of furnace and combustion air preheater configurations and technologies for enhancing convective and radiative heat transfer. The design evolution

  5. The effects of a flow obstacle on liquid film flowing concurrently with air in a horizontal rectangular duct

    International Nuclear Information System (INIS)

    Fukano, Tohru; Tominaga, Akira; Morikawa, Kengo.

    1986-01-01

    The aspect of a liquid film flowing near a flat plate type obstacle was observed, and the liquid film thickness and the entrainment were measured under a wide range of gas and liquid flow rates. The results are summarized as follows: (1) The configurations of film flows near the obstacle are classified according to whether (a) the liquid film climbs over the obstacle or not, (b) the air flows under the obstacle or not, or (c) the liquid film swells or sinks just upstream or downstream of the obstacle. (2) The lower the liquid flow rate, the larger the effect of the obstacle on the film thickness. (3) The generation of entrainment is regulated by the obstacle when the air volumetric flux is high and by the disturbance wave when it is low. (author)

  6. Investigation of the use of fly-ash based autoclaved cellular concrete blocks in coal mines for air duct work. Final report, January 25, 1993--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, M.L. [Ohio Edison Co., Akron, OH (United States)

    1995-06-19

    Coal mines are required to provide ventilation to occupied portions of underground mines. Concrete block is used in this process to construct air duct walls. However, normal concrete block is heavy and not easy to work with and eventually fails dramatically after being loaded due to mine ceiling convergence and/or floor heave. Autoclaved cellular concrete block made from (70{plus_minus}%) coal fly ash is lightweight and less rigid when loaded. It is lighter and easier to use than regular concrete block for underground mine applications. It has also been used in surface construction around the world for over 40 years. Ohio Edison along with eight other electric utility companies, the Electric Power Research Institute (EPRI), and North American Cellular Concrete constructed a mobile demonstration plant to produce autoclaved cellular concrete block from utility fly ash. To apply this research in Ohio, Ohio Edison also worked with the Ohio Coal Development Office and CONSOL Inc. to produce autoclaved cellular concrete block not only from coal ash but also from LIMB ash, SNRB ash, and PFBC ash from various clean coal technology projects sponsored by the Ohio Coal Development Office. The purpose of this project was to demonstrate the potential for beneficial use of fly ash and clean coal technology by-products in the production of lightweight block.

  7. Speciated VOC Emissions from an Outdoor Residential Pellet burning Hydronic Heater

    Science.gov (United States)

    Outdoor hydronic heaters used for residential heating emit air pollutants such as particulate matter and volatile organic compounds (VOCs), which can lead to deleterious impacts on local air quality and human health. Detailed speciated emissions measurements are required to accur...

  8. Printed heater on LTCC substrate

    OpenAIRE

    Karhu, A. (Anssi)

    2016-01-01

    Abstract In this bachelor thesis different kinds of printed heaters are discussed, with main attention put on low temperature co-fired ceramics (LTCC) based ones. Other types of printed heaters structures include thick-film, thin-film and micro heaters. LTCC is found to have very good electrical and mechanical properties, high reliability and stability, and furthermore the possibility of making three dimensioal (3D) microst...

  9. 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)

  10. Water heater control module

    Science.gov (United States)

    Hammerstrom, Donald J

    2013-11-26

    An advanced electric water heater control system that interfaces with a high temperature cut-off thermostat and an upper regulating thermostat. The system includes a control module that is electrically connected to the high-temperature cut-off thermostat and the upper regulating thermostat. The control module includes a switch to open or close the high-temperature cut-off thermostat and the upper regulating thermostat. The control module further includes circuitry configured to control said switch in response to a signal selected from the group of an autonomous signal, a communicated signal, and combinations thereof.

  11. Arkansas Solar Retrofit Guide. Greenhouses, Air Heaters and Water Heaters.

    Science.gov (United States)

    Skiles, Albert; Rose, Mary Jo

    Solar retrofits are devices of structures designed to be attached to existing buildings to augment their existing heating sources with solar energy. An investigation of how solar retrofits should be designed to suit the climate and resources of Arkansas is the subject of this report. Following an introduction (section 1), section 2 focuses on…

  12. Mammary Duct Ectasia

    Science.gov (United States)

    ... may worry that it's a sign of breast cancer, especially if you develop a hard lump around a milk duct affected by mammary duct ectasia. While it's important to get signs and symptoms checked out promptly, remember that mammary duct ectasia does not increase your risk of breast cancer. By Mayo ... . Mayo Clinic Footer Legal ...

  13. 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...

  14. 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...

  15. 49 CFR 393.77 - Heaters.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Heaters. 393.77 Section 393.77 Transportation... SAFE OPERATION Miscellaneous Parts and Accessories § 393.77 Heaters. On every motor vehicle, every heater shall comply with the following requirements: (a) Prohibited types of heaters. The installation or...

  16. Biobriefcase aerosol collector heater

    Science.gov (United States)

    Bell, Perry M [Tracy, CA; Christian, Allen T [Madison, WI; Bailey, Christopher G [Pleasanton, CA; Willis, Ladona [Manteca, CA; Masquelier, Donald A [Tracy, CA; Nasarabadi, Shanavaz L [Livermore, CA

    2009-03-17

    A system for sampling air and collecting particles potentially including bioagents entrained in the air for detection. The system comprises collecting a sample of the air with the particles entrained in the air, directing the sample to a receiving surface, directing a liquid to the receiving surface thereby producing a liquid surface, wherein the particles potentially including bioagents become captured in the liquid, and heating the liquid wherein the particles potentially including bioagents become heated to lysis the bioagents.

  17. 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.

  18. ENERGY STAR Certified Water Heaters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.2 ENERGY STAR Program Requirements for Water Heaters that are effective April 16, 2015....

  19. 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.

  20. 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

  1. Development of a High Temperature Heater using an Yttria Stabilized Zirconia Cored Brick Matrix

    Science.gov (United States)

    Smith, K. W.; Decoursin, D. G.

    1971-01-01

    The Ames pilot heater is a ceramic regenerative heater that provides high temperature air for aerodynamic and combustion experiments. The development of this heater to provide a heat storage bed with temperature capability of about 4600 R is described. A bed was designed and installed having cored brick elements of yttria-stabilized zirconia. The bed dimensions were 14 inches in diameter by 10 feet high. The thermal stress limitations of the bed were studied and maximum air flow rates based upon these limits were established. A combustion reheat system was designed and installed to provide the necessary control over the bed temperature distribution. The revised heater system was successfully operated at a maximum bed temperature of 4600 R. The successful operation demonstrated that yttria-stabilized zirconia cored brick can satisfy the high temperature-long duration requirement for storage heater applications.

  2. Emissions Characterization of Residential Wood-Fired Hydronic Heater Technologies

    Science.gov (United States)

    Residential wood-fired hydronic heaters (RWHHs) can negatively impact the local ambient air quality and thus are of major environmental concern in wood burning areas of the U. S. Few studies have been conducted which characterize the emissions from RWHHs. To address the lack of e...

  3. 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.

  4. 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.

  5. 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

  6. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  7. Evaluation of the Improved Flameless Ration Heater

    Science.gov (United States)

    2001-12-01

    heater " puffed up" when it was activated. (Heat may build up inside of the Tempra if it has no where to go, causing this heater to "puff up.") The seams...that the heater expanded (" puffed up") when it was activated. The seams of this heater have 31 sometimes been observed to separate when the heater...0 Did not use MRE heater (Please mark all that apply.) 0 Heated the entree (Chili Mac, etc) 0 Heated the starch ( Rice , etc) 0 Other (Please

  8. Note: Coaxial-heater hollow cathode

    Science.gov (United States)

    Kurt, Huseyin; Kokal, Ugur; Turan, Nazli; Celik, Murat

    2017-06-01

    The design and tests of a LaB6 hollow cathode with a novel heater are presented. In the new design, the heater wire is completely encapsulated around the cathode tube and a coaxial return electrode, thereby eliminating hot spots on the heater wire due to the free hanging regions. Since the new heater confines the Joule heating to the region of interest, where the LaB6 emitter is placed, the heater terminals are further secured from overheating. The cathode with the presented heater design has been successfully tested and is able to deliver currents in the 0.5-15 A range.

  9. Note: Coaxial-heater hollow cathode.

    Science.gov (United States)

    Kurt, Huseyin; Kokal, Ugur; Turan, Nazli; Celik, Murat

    2017-06-01

    The design and tests of a LaB 6 hollow cathode with a novel heater are presented. In the new design, the heater wire is completely encapsulated around the cathode tube and a coaxial return electrode, thereby eliminating hot spots on the heater wire due to the free hanging regions. Since the new heater confines the Joule heating to the region of interest, where the LaB 6 emitter is placed, the heater terminals are further secured from overheating. The cathode with the presented heater design has been successfully tested and is able to deliver currents in the 0.5-15 A range.

  10. An Appraisal of Duct-Related Microwave Link Degradation in Nigeria

    African Journals Online (AJOL)

    Studies have revealed considerable prevalence of surface ducts in Nigeria. This effort examines the climatic conditions that give rise to ducts and assesses their potential for degradation of microwave links in the country. The result based on analysis of clear-air meteorological data shows prevalence of strong surface ducts ...

  11. Patent nasopalatine duct: a diagnostic pitfall

    NARCIS (Netherlands)

    Valstar, M.H.; van den Akker, H.P.

    2008-01-01

    We describe a patient in whom the combination of excessive air in the maxillary sinus and the presence of a patent nasopalatine duct led to misdiagnosis and subsequent treatment of a non-existent oroantral perforation. When a radiograph indicates that antral involvement during removal of a maxillary

  12. Understanding the Residential Wood Heater Rules

    Science.gov (United States)

    Information on the components of the current wood heater new source performance standards (NSPS) and proposed updates to the NSPS including which types of heaters are covered under the rules and the benefits.

  13. Quench Heater Studies for the LHC Magnets

    CERN Document Server

    Rodríguez-Mateos, F

    2001-01-01

    About 2000 LHC (CERN's Large Hadron Collider) superconducting magnets will be protected with quench heaters against development of excessive voltage and overheating after a resistive transition. The quench heater strips are powered by capacitor bank discharge power supplies. The strips are made of stainless steel partially plated with copper to reduce their resistance and to allow for the connection of quench heaters in series. The strips are embedded in between two polyimide foils. The initial power density and the current decay time determine the quench heater effectiveness. Since only one type of heater power supply will be available, the copper plating cycle is adapted for the various magnet types to keep the resistance of the heater circuit constant. Different quench heater designs have been tested on various prototype magnets to optimise the copper-plating cycle and the electric insulation of the heater strip. This paper summarises the experimental results and computations that allowed to finalise the h...

  14. 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.

  15. Mammary Duct Ectasia

    Science.gov (United States)

    ... lumps Mammary duct ectasia Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. 14 CFR 27.833 - Heaters.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Heaters. 27.833 Section 27.833 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Heaters. Each combustion heater must be approved. [Amdt. 27-23, 53 FR 34210, Sept. 2, 1988] Fire...

  1. 14 CFR 29.833 - Heaters.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Heaters. 29.833 Section 29.833 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Heaters. Each combustion heater must be approved. Fire Protection ...

  2. 21 CFR 884.5390 - Perineal heater.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Perineal heater. 884.5390 Section 884.5390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... Perineal heater. (a) Identification. A perineal heater is a device designed to apply heat directly by...

  3. An outbreak of Serratia marcescens infection in a special-care baby unit of a community hospital in United Arab Emirates: the importance of the air conditioner duct as a nosocomial reservoir.

    Science.gov (United States)

    Uduman, S A; Farrukh, A S; Nath, K N R; Zuhair, M Y H; Ifrah, A; Khawla, A D; Sunita, P

    2002-11-01

    We report an outbreak of Serratia marcescens infection in a special-care baby unit (SCBU) of a university-affiliated community hospital in the United Arab Emirates. The outbreak involved 36 infants and lasted for 20 weeks. Seven of the colonized infants developed invasive illnesses in the form of bacteraemia (four cases), bacteraemic meningitis (two) and clinical sepsis (one). Three other term infants had purulent conjunctivitis. There were five deaths with an overall mortality of 14%. S. marcescens was cultured from airflow samples from the air conditioning (AC) which was the reservoir of infection in this outbreak. Elimination of the nosocomial source and outbreak containment were eventually achieved by specialized robotic cleaning of the entire AC duct system of the SCBU. Strict adherence to the infection control policies was reinforced to prevent transmission of cross-infection. Copyright 2002 The Hospital Infection Society

  4. 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.

  5. 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.

  6. FFTF reactor immersion heaters. Revision 1

    International Nuclear Information System (INIS)

    Romrell, D.M.

    1994-01-01

    This specification establishes requirements for design, testing, and quality assurance for electric heaters that will be used to maintain primary Sodium temperature in the Fast Test Facility (FFTF) reactor vessel. The Test Specification (WHC-SD-FF-SDS-003) has been revised to Rev. 1. This change modifies the fabrication of approximately 25 feet of the subject heater using ceramic insulators over the heater lead wire rather than compressed magnesium oxide. Also, 304 or 316 stainless steel can be used for the heater sheath. This change should simplify fabrication and improve the heater operational reliability

  7. Solar Air Heaters with Thermal Heat Storages

    OpenAIRE

    Saxena, Abhishek; Goel, Varun

    2013-01-01

    Solar energy can be converted into different forms of energy, either to thermal energy or to electrical energy. Solar energy is converted directly into electrical power by photovoltaic modules, while solar collector converts solar energy into thermal energy. Solar collector works by absorbing the direct solar radiation and converting it into thermal energy, which can be stored in the form of sensible heat or latent heat or a combination of sensible and latent heats. A theoretical study has be...

  8. 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.

  9. Wind-Tunnel Investigation of Rectangular Air-Duct Entrances in the Leading Edge of an NACA 23018 Wing, Special Report

    Science.gov (United States)

    Biermann, David; McLellan, Charles H.

    1940-01-01

    A preliminary investigation of a number of duct entrances of rectangular shape installed in the leading edge of a wing was conducted in the NACA 20-foot tunnel to determine the external drag, the available pressure, the critical Mach numbers, and the effect on the maximum lift. The results showed that the most satisfactory entrances, which had practically no effect on the wing characteristics, had their lips approximately in the vertical plane of the leading edge of the wing. This requirement necessitated extending the lips outside the wing contour for all except the small entrances. Full dynamic pressure was found to be available over a fairly wide range of angle of attack. The critical Mach number for a small entrance was calculated to be as high as that for the plain wing but was slightly lower for the larger entrances tested.

  10. 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

  11. Heater Development, Fabrication, and Testing: Analysis of Fabricated Heaters

    Science.gov (United States)

    Bragg-Sitton, S. M.; Dickens, R. E.; Farmer, J. T.; Davis, J. D.; Adams, M. R.; Martin, J. J.; Webster, K. L.

    2008-01-01

    Thermal simulators (highly designed heater elements) developed at the Early Flight Fission Test Facility (EFF-TF) are used to simulate the heat from nuclear fission in a variety of reactor concepts. When inserted into the reactor geometry, the purpose of the thermal simulators is to deliver thermal power to the test article in the same fashion as if nuclear fuel were present. Considerable effort has been expended to mimic heat from fission as closely as possible. To accurately represent the fuel, the simulators should be capable of matching the overall properties of the nuclear fuel rather than simply matching the fuel temperatures. This includes matching thermal stresses in the pin, pin conductivities, total core power, and core power profile (axial and radial). This Technical Memorandum discusses the historical development of the thermal simulators used in nonnuclear testing at the EFF-TF and provides a basis for the development of the current series of thermal simulators. The status of current heater fabrication and testing is assessed, providing data and analyses for both successes and failures experienced in the heater development and testing program.

  12. 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.

  13. 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.

  14. Convective heat transfer in airflow through a duct with wall thermal radiation

    International Nuclear Information System (INIS)

    Chandratilleke, T T; Narayanaswamy, R; Wangdhamkoom, P

    2010-01-01

    This paper presents a numerical investigation on airflow through a heated horizontal rectangular duct wherein the model considers the combined modes of natural and forced convection heat transfer and the thermal radiation from duct walls. The duct periphery is differentially heated with known temperature profiles imposed on the two opposite vertical sidewalls while the other two walls are treated as adiabatic. The air enters into the duct hydrodynamically fully developed and flows steadily under laminar conditions undergoing thermal development within the duct. Considering several temperature profiles on the two vertical sidewalls, the numerical simulation generates the heat transfer rates and associated fluid flow patterns in the duct for a range of airflow rates, duct aspect ratios and surface emissivity. The variation of local Nusselt number at duct walls and the fluid flow patterns are critically examined to identify thermal instabilities and the significance of wall thermal radiation effects on the overall heat transfer rates.

  15. 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

  16. 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.

  17. Silicon photonic heater-modulator

    Science.gov (United States)

    Zortman, William A.; Trotter, Douglas Chandler; Watts, Michael R.

    2015-07-14

    Photonic modulators, methods of forming photonic modulators and methods of modulating an input optical signal are provided. A photonic modulator includes a disk resonator having a central axis extending along a thickness direction of the disk resonator. The disk resonator includes a modulator portion and a heater portion. The modulator portion extends in an arc around the central axis. A PN junction of the modulator portion is substantially normal to the central axis.

  18. Near-surface heater experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, L.D.; Cuderman, J.F.; Krumhansl, J.L.; Lappin, A.

    1978-12-31

    Full-scale near-surface heater experiments are presently being conducted by Sandia Laboratories in the Conasauga Formation at Oak Ridge, Tennessee, and in the Eleana Formation on the Nevada Test Site, Nevada. The purposes of these experiments are: (1) to determine if argillaceous media can withstand thermal loads characteristic of high level waste; (2) to provide data for improvement of themomechanical modeling of argillaceous rocks; (3) to identify instrumentation development needed for further in situ testing; and (4) to identify unexpected general types of behavior, if any. The basic instrumentation of these tests consists of a heater in a central hole, surrounded by arrays of holes containing various instrumentation. Temperatures, thermal profiles, vertical displacements, volatile pressurization, and changes in in situ stresses are measured in each experiment as a function of time, and compared with pretest modeling results. Results to date, though in general agreement with modeling results assuming conductive heat transfer within the rock, indicate that the presence of even small amounts of water can drastically affect heat transfer within the heater hole itself, and that small amounts of upward convection of water may be occurring in the higher temperature areas of the Conasauga experiments.

  19. Primary zone air proportioner

    Science.gov (United States)

    Cleary, Edward N. G.

    1982-10-12

    An air proportioner is provided for a liquid hydrocarbon fueled gas turbine of the type which is convertible to oil gas fuel and to coal gas fuel. The turbine includes a shell for enclosing the turbine, an air duct for venting air in said shell to a gasifier, and a fuel injector for injecting gasified fuel into the turbine. The air proportioner comprises a second air duct for venting air from the air duct for mixing with fuel from the gasifier. The air can be directly injected into the gas combustion basket along with the fuel from the injector or premixed with fuel from the gasifier prior to injection by the fuel injector.

  20. Bile Duct Exploration

    Science.gov (United States)

    ... 223.2273 Request an Appointment Contact Us Share Facebook Twitter Linkedin Email Bile Duct Exploration Menu Print Full Article Overview Test Details Results and Follow-Up Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We ...

  1. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  2. Entrainment and deposition studies in two-phase cross flow: comparison between air-water and steam-water in a square horizontal duct. Technical report (final)

    International Nuclear Information System (INIS)

    Berryman, R.J.; Ralph, J.C.; Wade, C.D.

    1981-03-01

    Air-water simulation studies of two phase steam water flow relevant to the upper plenum of a PWR during reflood situations have recently been undertaken at Harwell for the US Nuclear Regulatory Commission. In order to give confidence that the simulation fluids were capable of modelling the important features of the actual system, a relatively basic comparison experiment has been carried out. Water entrainment and deposition tests have been carried out on a pair of 2.5 cm diameter vertical rods mounted in a cross flow of steam or air in a 10.2 cm x 10.2 cm tunnel. The air and steam systems exhibited similar characteristics to one another. A 'critical' film flowrate was identified for the rods which, once reached, either by injection through the sinters or by entrainment from the main two phase stream, was not exceeded with further water addition. The 'critical' film flowrate decreased with increase of cross flow velocity and was lower for air than steam at the same velocity. The results from the air and steam tests were found to be reasonably well correlated on the basis of the cross flow momentum flux of the air or steam

  3. 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

  4. Environmental Technology Verification: Supplement to Test/QA Plan for Biological and Aerosol Testing of General Ventilation Air Cleaners; Bioaerosol Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners

    Science.gov (United States)

    The Air Pollution Control Technology Verification Center has selected general ventilation air cleaners as a technology area. The Generic Verification Protocol for Biological and Aerosol Testing of General Ventilation Air Cleaners is on the Environmental Technology Verification we...

  5. 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.

  6. 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.

  7. 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.

  8. Two death cases originating from supplementary heater in the cabins of parked trucks.

    Science.gov (United States)

    Demirci, Serafettin; Dogan, Kamil Hakan; Erkol, Zerrin; Gunaydin, Gursel

    2009-02-01

    A supplementary heater can be mounted in trucks or other transportation vehicles and used to heat the air in the cabin independent of the engine of the vehicle. This apparatus works with diesel fuel or gasoline. Combustion products burning in the pre-combustion chamber heat the fins of the engine. The air passing through the fins is heated and is transferred into the cabin. The malfunction of such an apparatus may be the cause of carbon monoxide (CO) poisoning or fire. In this study, we report two cases in which drivers died while asleep in the cabins of parked trucks. In the first case, a 43-year-old man died because of CO poisoning originating from a broken supplementary heater. In the second case, a 48-year-old man died owing to a fire that resulted from the burning of upholstery cloths in the truck cabin, and which was caused by a supplementary heater set at very high temperatures. In both cases, it was determined by a technical expert that the CO poisoning in the first case and the fire in the second case were caused by the supplementary heater in the trucks. It is emphasized in this article that the supplementary heater in the truck might be the cause of mortal CO poisoning as well as be responsible for fires in the cabins of the trucks. It aims to highlight that a detailed investigation of supplementary heaters at the death scene is required for such death cases in the trucks.

  9. Heat Transfer Enhancement In a Ribbed Duct

    Directory of Open Access Journals (Sweden)

    J.M. Jalil

    2006-12-01

    Full Text Available The rib enhancement of heat transfer in a duct is studied numerically and experimentally, where hot air passes through a duct (0.04 x 0.16 x 1.15 m3 with different rib arrangement. The arranments are lower 12-rib arrangement; upper 12 rib arrangement and 24 rib staggered arrangement. The staggered arrangement gives better performance than the others. Also, the angle of attack was studied for lower arrangement, three different values were tested (45°, 60° and 90°. Angle of 60° gives better performance. Numerically, the three-dimension continuity, Navier-Stokes and energy   by finite volume method of flow of air through (0.04 x 0.16 x 0.6 m3. Validation of the code was performed by comparing the numerical result with the results obtained experimentally for staggered arrangement only. The agreement seems acceptable. The numerical studies were extended to study the case of cold air passing through hot ribbed duct.

  10. 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

  11. 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

  12. Combustion heater for oil shale

    Science.gov (United States)

    Mallon, Richard G.; Walton, Otis R.; Lewis, Arthur E.; Braun, Robert L.

    1985-01-01

    A combustion heater for oil shale heats particles of spent oil shale containing unburned char by burning the char. A delayed fall is produced by flowing the shale particles down through a stack of downwardly sloped overlapping baffles alternately extending from opposite sides of a vertical column. The delayed fall and flow reversal occurring in passing from each baffle to the next increase the residence time and increase the contact of the oil shale particles with combustion supporting gas flowed across the column to heat the shale to about 650.degree.-700.degree. C. for use as a process heat source.

  13. SELECTED ORGANIC POLLUTANT EMISSIONS FROM UNVENTED KEROSENE HEATERS

    Science.gov (United States)

    An exploratory study was performed to assess the semivolatile and nonvolatile organic pollutant emission rates from unvented kerosene space heaters. A well-tuned radiant heater and maltuned convective heater were tested for semivolatile and nonvolatile organic pollutant emiss...

  14. 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

  15. Designing a Methodology for Optimisation of Heater Treater

    OpenAIRE

    Chadha, Deepankar; Chaudhary, Pulkit

    2016-01-01

    Emulsions refer to mixture of two or more immiscible liquids. For an emulsion to form the components should be immiscible with each other. Various equipments are available in the oil and gas industry. Heater treaters are predominantly used in the oil industry. Heater treater, as the name implies, heat the feed to break the emulsion. There are two types of heater treaters i.e. horizontal heater treaters and vertical heater treaters. Vertical heater treaters are used when the flow is coming fro...

  16. 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.

  17. 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.

  18. Cylindrical solar heater for low cost housing

    Energy Technology Data Exchange (ETDEWEB)

    Nahar, N.M.; Malhotra, K.S.

    1981-07-01

    A circular cylindrical type solar water heater has been designed, developed and tested. This heater can supply 50 litres of hot water at 50/sup 0/C in winter afternoon when tap water is 15/sup 0/C. The cost of manufacturing is only Rs. 150. It can be fabricated by any village carpenter blacksmith.

  19. 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)

  20. Examination and life assessment of field-tested heat-pump water heaters

    Science.gov (United States)

    Bernardi, W. P.; Blevins, R. P.; Sloane, B. D.

    1982-12-01

    An electric heat pump water heater (HPWH) was developed for domestic use. This device is interchangeable with conventional electric or oil fired water heaters but significantly reduces energy consumption by using air conditioning technology, the HPWH removes heat from the surrounding air and rejects the heat to its integral water tank. Design, development, and an 85 unit field of the HPWH are demonstrated. The results of destructive examination of 20 units which had operated for 2 years are presented. Life expectancy and the need for redesign are evaluated.

  1. 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).

  2. 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)

  3. 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.

  4. 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

  5. Duct having oscillatory side wall

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Effects of heated seat and foot heater on thermal comfort and heater energy consumption in vehicle.

    Science.gov (United States)

    Oi, Hajime; Yanagi, Kotaro; Tabata, Koji; Tochihara, Yutaka

    2011-08-01

    Subjective experiments involving 12 different conditions were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal sensation and thermal comfort. The experimental conditions involved various combinations of the operative temperature in the test room (10 or 20°C), a heated seat (on/off) and a foot heater (room operative temperature +10 or +20°C). The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. The room operative temperature at which the occupants felt a 'neutral' overall thermal sensation was decreased by about 3°C by using the heated seat or foot heater and by about 6°C when both devices were used. Moreover, the effects of these devices on vehicle heater energy consumption were investigated using simulations. As a result, it was revealed that heated seats and foot heaters can reduce the total heater energy consumption of vehicles. Statement of Relevance: Subjective experiments were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal comfort. The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. These devices can reduce the total heater energy consumption in vehicles.

  7. Condition assessment of closed feedwater heaters

    International Nuclear Information System (INIS)

    Bell, R.J.

    1995-01-01

    Feedwater heaters are often forgotten in condition assessments plans. While they have no moving parts, these components have a significant impact on plant performance equivalent availability. Condition assessment of feedwater heaters includes not only an analysis of the tubing, which because of its thin wall nature is the primary objective of analysis, but other failure causes, such as tube joint leaks, an adverse condition which can and often does occur. For these reasons a comprehensive condition assessment program should be employed. This paper will identify the three level approach suggested by EPRI and many of the testing methods used to assess feedwater heater condition

  8. 14 CFR 23.859 - Combustion heater fire protection.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Combustion heater fire protection. 23.859... Construction Fire Protection § 23.859 Combustion heater fire protection. (a) Combustion heater fire regions. The following combustion heater fire regions must be protected from fire in accordance with the...

  9. 40 CFR 65.149 - Boilers and process heaters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Boilers and process heaters. 65.149... System or a Process § 65.149 Boilers and process heaters. (a) Boiler and process heater equipment and operating requirements. (1) Owners or operators using boilers and process heaters to meet the 98 weight...

  10. 49 CFR 179.12 - Interior heater systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Interior heater systems. 179.12 Section 179.12... Design Requirements § 179.12 Interior heater systems. (a) Interior heater systems shall be of approved... each compartment. (b) Each interior heater system shall be hydrostatically tested at not less than 13...

  11. Modal analysis of an ECC duct for APR+ reactor barrel

    International Nuclear Information System (INIS)

    Kang, H.S.; Lee, K.H.; Kwon, T.S.

    2011-01-01

    Advanced Power Reactor Plus (APR+) provides four Direct Vessel Injection (DVI) ducts on the reactor barrel to enhance the performance of Emergency Core Cooling System (ECCS). Several studies on safety analysis have verified the excellent performance of the DVI duct. In this study, from the viewpoint of mechanical integrity, modal analyses of two full-scaled DVI ducts have been presented; both numerical analysis and modal tests have been performed in air and water. It was found that the numerical simulation and modal test coincide with each other. The DVI duct is a thin shell of 5 mm thickness, so that harmonic responses to RCP blade passing frequencies should be checked. The dominant passing frequencies are known to be 20, 40, 60, 120 and 240 Hz. In addition, an interesting thing in this study is that added mass effect by coolant seems to be so significant that the natural frequency of the ducts under water could be considerably low as compared with those in air; the natural frequency under water is 60 % lower than that in air. (author)

  12. Intrahepatic transposition of bile ducts.

    Science.gov (United States)

    Delić, Jasmin; Savković, Admedina; Isaković, Eldar; Marković, Sergije; Bajtarevic, Alma; Denjalić, Amir

    2012-01-01

    Objective. To describe the intrahepatic bile duct transposition (anatomical variation occurring in intrahepatic ducts) and to determine the frequency of this variation. Material and Methods. The researches were performed randomly on 100 livers of adults, both sexes. Main research methods were anatomical macrodissection. As a criterion for determination of variations in some parts of bile tree, we used the classification of Segmentatio hepatis according to Couinaud (1957) according to Terminologia Anatomica, Thieme Stuugart: Federative Committee on Anatomical Terminology, 1988. Results. Intrahepatic transposition of bile ducts was found in two cases (2%), out of total examined cases (100): right-left transposition (right segmental bile duct, originating from the segment VIII, joins the left liver duct-ductus hepaticus sinister) and left-right intrahepatic transposition (left segmental bile duct originating from the segment IV ends in right liver duct-ductus hepaticus dexter). Conclusion. Safety and success in liver transplantation to great extent depends on knowledge of anatomy and some common embryological anomalies in bile tree. Variations in bile tree were found in 24-43% of cases, out of which 1-22% are the variations of intrahepatic bile ducts. Therefore, good knowledge on ductal anatomy enables good planning, safe performance of therapeutic and operative procedures, and decreases the risk of intraoperative and postoperative complications.

  13. 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....

  14. 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.

  15. 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)

  16. ENERGY STAR Certified Commercial Water Heaters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Commercial Water Heaters that are effective as...

  17. Feedwater heaters functional analysis at Embalse NGS

    International Nuclear Information System (INIS)

    Lolis, R.R.

    1992-01-01

    This study is concerned with the analysis or feedwater heaters, to detect actual failure or a bad trend beyond acceptable operating limits. When these situations are identified, preventive or corrective maintenance must be done. 2 tabs., 14 figs

  18. Note: Improved wire-wound heater.

    Science.gov (United States)

    Steinmann, Ricardo G; Vitoux, Hugo

    2015-01-01

    The authors have measured, at cryogenic temperature, the upper limit of the heat transfer in different configurations of a wire-wound heater. We found that the heat transferred has an upper limit of about 15 W/cm(2) and is dependent on the diameter of the wire. In this paper, we present three ways of increasing the heat transferred by this type of heater and its application in different continuous flow cryostats.

  19. Diesel particulate filter with zoned resistive heater

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-03-08

    A diesel particulate filter assembly comprises a diesel particulate filter (DPF) and a heater assembly. The DPF filters a particulate from exhaust produced by an engine. The heater assembly has a first metallic layer that is applied to the DPF, a resistive layer that is applied to the first metallic layer, and a second metallic layer that is applied to the resistive layer. The second metallic layer is etched to form a plurality of zones.

  20. 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

  1. Measure Guideline: Buried and/or Encapsulated Ducts

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Zoeller, W.; Mantha, P.

    2013-08-01

    Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. This Building America Measure Guideline synthesizes previously published research on BEDs and provides practical information to builders, contractors, homeowners, policy analysts, building professions, and building scientists. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license. Persons implementing duct system improvements should not go beyond their expertise or qualifications. This guideline provides valuable information for a building industry that has struggled to address ductwork thermal losses in new and existing homes. As building codes strengthen requirements for duct air sealing and insulation, flexibility is needed to address energy efficiency goals. While ductwork in conditioned spaces has been promoted as the panacea for addressing ductwork thermal losses, BEDs installations approach - and sometimes exceed - the performance of ductwork in conditioned spaces.

  2. Phase change material storage heater

    Science.gov (United States)

    Goswami, D. Yogi; Hsieh, Chung K.; Jotshi, Chand K.; Klausner, James F.

    1997-01-01

    A storage heater for storing heat and for heating a fluid, such as water, has an enclosure defining a chamber therein. The chamber has a lower portion and an upper portion with a heating element being disposed within the enclosure. A tube through which the fluid flows has an inlet and an outlet, both being disposed outside of the enclosure, and has a portion interconnecting the inlet and the outlet that passes through the enclosure. A densely packed bed of phase change material pellets is disposed within the enclosure and is surrounded by a viscous liquid, such as propylene glycol. The viscous liquid is in thermal communication with the heating element, the phase change material pellets, and the tube and transfers heat from the heating element to the pellets and from the pellets to the tube. The viscous fluid has a viscosity so that the frictional pressure drop of the fluid in contact with the phase change material pellets substantially reduces vertical thermal convection in the fluid. As the fluid flows through the tube heat is transferred from the viscous liquid to the fluid flowing through the tube, thereby heating the fluid.

  3. Air

    Science.gov (United States)

    ... gov/ Home The environment and your health Air Air While we don’t often think about the ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be ...

  4. 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.

  5. Modelling the Pressure Profile for Optical Cables in Ducts

    NARCIS (Netherlands)

    Snippe, A.; Bresser, O.R.; Hoekstra, Sipke; Griffioen, A.

    2013-01-01

    The longitudinal pressure profile is an important parameter when calculating the correct blowing force during the process of installing optical fiber cables using the viscous flow of air. This paper presents a model of the pressure inside the duct that contains a moving cable. This new model of the

  6. 3-D numerical study of the effect of Reynolds number and baffle angle on heat transfer and pressure drop of turbulent flow of air through rectangular duct of very small height

    Directory of Open Access Journals (Sweden)

    Abhijit Paul

    2016-09-01

    Full Text Available Present article illustrates a computational study of three-dimensional steady state heat transfer and high turbulent flow characteristics through a rectangular duct with constant heat fluxed upper wall and single rectangular cross-sectioned baffle insertion at different angles. RNG k–ɛ model along with standard wall function based computations has been accomplished applying the finite volume method, and SIMPLE algorithm has been executed for solving the governing equations. For a Reynolds number, Re of 10,000 to 50,000, Prandtl Number, Pr of 0.707 and baffle angle, α of 30°, 60°, 90°, 120°, 150°, computational studies are executed, centred onto the hydraulic diameter, Dh, test section and hydrodynamic entry length of the duct. Flow field has been solved using Ansys Fluent 14.0 software. Study exposes that baffled rectangular duct has a higher average Nusselt number, Nu and Darcy friction factor, f compared to a smooth rectangular duct. Nu as well as f are found to be maximum at 90° baffle angle. Results illustrate that both α and Re play a significant role in heat transfer as well as flow characteristics and also effects TEF. The correctness of the results attained in this study is corroborated by comparing the results with those existing in the literature for smooth rectangular duct within a precision of ±2% for f and ±4% for Nu.

  7. 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.

  8. 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.

  9. Vortex Shedding Inside a Baffled Air Duct

    Science.gov (United States)

    Davis, Philip; Kenny, R. Jeremy

    2010-01-01

    Common in the operation of both segmented and un-segmented large solid rocket motors is the occurrence of vortex shedding within the motor chamber. A portion of the energy within a shed vortex is converted to acoustic energy, potentially driving the longitudinal acoustic modes of the motor in a quasi-discrete fashion. This vortex shedding-acoustic mode excitation event occurs for every Reusable Solid Rocket Motor (RSRM) operation, giving rise to subsequent axial thrust oscillations. In order to better understand this vortex shedding/acoustic mode excitation phenomena, unsteady CFD simulations were run for both a test geometry and the full scale RSRM geometry. This paper covers the results from the subscale geometry runs, which were based on work focusing on the RSRM hydrodynamics. Unsteady CFD simulation parameters, including boundary conditions and post-processing returns, are reviewed. The results were further post-processed to identify active acoustic modes and vortex shedding characteristics. Probable locations for acoustic energy generation, and subsequent acoustic mode excitation, are discussed.

  10. Salivary duct carcinoma.

    Science.gov (United States)

    D'heygere, Emmanuel; Meulemans, Jeroen; Vander Poorten, Vincent

    2018-01-25

    The review puts new information on geno- and phenotype of salivary duct carcinoma (SDC) in the perspective of the updated 2017 WHO classification. The proportion of SDC is increasing. This may be because of a true rise in incidence, but certainly to better diagnostic tests and changed WHO definitions. In this light, a substantial proportion of carcinoma expleomorphic adenoma is now attributed to the category of SDC. 'Low-grade SDC' and 'SDC in-situ' of the former WHO classification, are now named low-grade and high-grade intraductal carcinoma (IDC), respectively. Recent series quantify biologic aggressiveness: perineural growth, vascular invasion, and extracapsular extension in lymph node metastasis are each observed in two out of three patients with SDC. Most patients die within 3 years, but once 5-year disease-free survival is reached, further disease activity is exceptional. The typical molecular biological profile with high human epidermal growth factor receptor 2 and androgen receptor expression is increasingly successfully exploited in clinical trials for advanced SDC. The aggressive SDC is increasingly diagnosed. Despite intensive combined surgery and radiation therapy, many patients recur, for whom new bullets, targeting the molecular biological mechanisms, are the subject of ongoing clinical trials.

  11. Bonded Invar Clip Removal Using Foil Heaters

    Science.gov (United States)

    Pontius, James T.; Tuttle, James G.

    2009-01-01

    A new process uses local heating and temperature monitoring to soften the adhesive under Invar clips enough that they can be removed without damaging the composite underneath or other nearby bonds. Two 1x1 in. (approx.2.5x2.5 cm), 10-W/sq in. (approx.1.6-W/sq cm), 80-ohm resistive foil Kapton foil heaters, with pressure-sensitive acrylic adhesive backing, are wired in parallel to a 50-V, 1-A limited power supply. At 1 A, 40 W are applied to the heater pair. The temperature is monitored in the clip radius and inside the tube, using a dual thermocouple readout. Several layers of aluminum foil are used to speed the heat up, allowing clips to be removed in less than five minutes. The very local heating via the foil heaters allows good access for clip removal and protects all underlying and adjacent materials.

  12. Substrate heater for thin film deposition

    Science.gov (United States)

    Foltyn, Steve R.

    1996-01-01

    A substrate heater for thin film deposition of metallic oxides upon a target substrate configured as a disk including means for supporting in a predetermined location a target substrate configured as a disk, means for rotating the target substrate within the support means, means for heating the target substrate within the support means, the heating means about the support means and including a pair of heating elements with one heater element situated on each side of the predetermined location for the target substrate, with one heater element defining an opening through which desired coating material can enter for thin film deposition and with the heating means including an opening slot through which the target substrate can be entered into the support means, and, optionally a means for thermal shielding of the heating means from surrounding environment is disclosed.

  13. 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.

  14. The effect of duct cleaning on perceived work environment and symptoms of office employees in non-problem buildings

    Energy Technology Data Exchange (ETDEWEB)

    Kolari, Sirpa; Luoma, Marianna [VTT Technical Research Centre of Finland, P.O. Box 1804, 02044 VTT (Finland); Heikkilae-Kallio, Ulla; Korhonen, Pirjo; Nykyri, Erkki; Reijula, Kari [Finnish Institute of Occupational Health, Arinatie 3 A, 00370 Helsinki (Finland); Pasanen, Pertti [Department of Environmental Sciences, University of Kuopio, P.O. Box 1627, 70211 Kuopio (Finland)

    2005-12-01

    The effect of duct cleaning on perceived work environment and symptom prevalence was investigated in ten non-problem office buildings. The supply air quality, duct hygiene, ventilation rate and air flow were measured. A questionnaire (MM-40-FIN) on work environment and symptoms was carried out. Duct cleaning had no detectable effect on measured air quality. As expected, the only change was the amount of dust deposited on inner duct surfaces, which decreased significantly due to cleaning. The most significant improvement in work environment factors due to duct cleaning was detected with stuffy 'bad' air (p<0.001) and work-related nasal symptoms (p<0.01). (author)

  15. Optimum cystic duct closure: a comparative study using metallic clips, ENSEAL, and ENDOLOOP in swine.

    Science.gov (United States)

    McVay, Derek; Nelson, Daniel; Porta, Christopher R; Blair, Kelly; Martin, Matthew

    2013-05-01

    Metal clips are commonly used to secure the cystic duct during cholecystectomy, although use of an ENDOLOOP (Ethicon Endo-Surgery, Blue Ash, OH) is often touted as a more secure closure when postoperative endoscopic retrograde cholangiopancreatography (ERCP) is anticipated. The objective of this study was to test the strength of 3 different cystic duct closure methods in a model simulating postoperative biliary insufflation. The extrahepatic biliary system, including common bile duct, gallbladder, and cystic duct, was harvested en bloc from 22 swine postmortem. A cholecystectomy was performed and the cystic duct was secured using 1 of 3 randomly assigned methods: metallic clips (Ethicon Endo-Surgery), an ENDOLOOP (Ethicon Endo-Surgery), or an ENSEAL tissue sealing device (Ethicon Endo-Surgery). The common bile duct was cannulated with a pressure-monitoring system and insufflated with air. The burst pressures, location of rupture, and size of the common bile duct and cystic duct were recorded and compared. There were 7 pigs each in the ENDOLOOP and ENSEAL groups and 8 in the metallic clip group, with no statistical significance between cystic and common bile duct size. Mean burst pressure was 432 mm Hg for metallic clips, 371 mm Hg for the ENDOLOOP, and 238 mm Hg for the ENSEAL device (P = .02). Post hoc analysis revealed clips to be statistically superior when compared with the ENSEAL (P= .01). There was no statistical difference between the ENDOLOOP and metal clips or between the ENDOLOOP and the ENSEAL. All 3 closure methods successfully secured the cystic duct, with mean burst pressures exceeding 195 mm Hg. Metallic clips demonstrated the highest burst pressures and no cystic duct stump leaks. This study challenges the traditional dogma of additionally securing the cystic duct with an ENDOLOOP when postoperative biliary instrumentation is expected and also suggests that an adequately secure closure may be obtained with thermal sealing devices. Published by

  16. Measure Guideline. Transitioning to a Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Brozyna, K. [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, A. [IBACOS, Inc., Pittsburgh, PA (United States)

    2012-09-01

    This measure guideline provides information to help residential builders and retrofitters with the design, specification, selection, implementation, installation, and maintenance issues of transitioning from tank-type water heaters to tankless water heaters.

  17. 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.

  18. Analysis of the performance and space-conditioning impacts of dedicated heat-pump water heaters

    Science.gov (United States)

    Morrison, L.; Swisher, J.

    1980-12-01

    The operation of a newly marketed dedicated heat pump water heater (HPWH) which utilizes an air to water heat pump, costs about $1000 installed, and obtains a coefficient of performance (COP) of about 2.0 in laboratory and field tests, is a space conditioning benefit if an air conditioning load exists and a penalty if a space heating load exists. A simulation was developed to model the thermal performance of a residence with resistance baseboard heat, air conditioning, and either heat pump or resistance water heating. The building characteristics were adapted (Madison, Wisconsin; Washington, DC; and Ft. Worth, Texas) and the system was simulated for a year with typical weather data. For each city, HPWH COPs are calculated monthly and yearly. The water heating and space conditioning energy requirements of HPWH operation are compared with those of resistance water heater operation to determine the relative performance ratio of the HPWH.

  19. 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

  20. Heater size effect on subcooled pool boiling of FC-72

    Energy Technology Data Exchange (ETDEWEB)

    Raj, Rishi; Kim, Jungho [University of Maryland, College Park, MD (United States). Dept. of Mechanical Engineering

    2009-07-01

    Extensive research has been conducted on pool boiling using heaters larger than the capillary length. For large heaters and/or high gravity conditions, boiling is dominated by buoyancy, and the heat transfer is heater size independent. Much less is known about boiling on small heaters and at low gravity levels. The ratio of heater size L{sub h} to capillary length L{sub c} is an important parameter in the determination of heater size dependence on heat transfer. As the ratio L{sub h}/L{sub c} decreases due to a decrease in either heater size or gravity, surface tension forces become dominant. It is proposed that transition from buoyancy to surface tension dominated boiling occurs when the heater size and bubble departure diameter are of the same order. Previous work in variable gravity with flat surfaces has shown that the heat transfer was heater size independent only when the ratio L{sub h}/L{sub c} was considerably larger than 1. An array of 96 platinum resistance heater elements in a 10 x 10 configuration with individual elements 0.7 x 0.7 mm{sup 2} in size was used to vary heater size and measure the heat transfer. The threshold value of L{sub h}/L{sub c} above which pool boiling is heater size independent was found to be about 2.8. (author)

  1. 21 CFR 868.5270 - Breathing system heater.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing system heater. 868.5270 Section 868.5270...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5270 Breathing system heater. (a) Identification. A breathing system heater is a device that is intended to warm breathing gases before they enter...

  2. Heater size effect on subcooled pool boiling of FC-72

    International Nuclear Information System (INIS)

    Raj, Rishi; Kim, Jungho

    2009-01-01

    Extensive research has been conducted on pool boiling using heaters larger than the capillary length. For large heaters and/or high gravity conditions, boiling is dominated by buoyancy, and the heat transfer is heater size independent. Much less is known about boiling on small heaters and at low gravity levels. The ratio of heater size L h to capillary length L c is an important parameter in the determination of heater size dependence on heat transfer. As the ratio L h /L c decreases due to a decrease in either heater size or gravity, surface tension forces become dominant. It is proposed that transition from buoyancy to surface tension dominated boiling occurs when the heater size and bubble departure diameter are of the same order. Previous work in variable gravity with flat surfaces has shown that the heat transfer was heater size independent only when the ratio L h /L c was considerably larger than 1. An array of 96 platinum resistance heater elements in a 10 x 10 configuration with individual elements 0.7 x 0.7 mm 2 in size was used to vary heater size and measure the heat transfer. The threshold value of L h /L c above which pool boiling is heater size independent was found to be about 2.8. (author)

  3. 46 CFR 111.70-5 - Heater circuits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Heater circuits. 111.70-5 Section 111.70-5 Shipping... REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-5 Heater circuits. (a) If an enclosure for a motor, master switch, or other equipment has an electric heater inside the enclosure that is energized...

  4. 7 CFR 58.215 - Pre-heaters.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Pre-heaters. 58.215 Section 58.215 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....215 Pre-heaters. The pre-heaters shall be of stainless steel or other equally corrosion resistant...

  5. Infrared heater arrays for warming grazingland field plots

    Science.gov (United States)

    In order to study the likely effects of global warming on rangeland and other ecosystems in the future, we developed arrays of infrared heaters that can produce uniform warming across 3-m-diameter field plots. The efficiency of the heaters was higher than that of the heaters used in most previous in...

  6. Demonstration of Tankless Water Heaters in Army Family Housing

    Science.gov (United States)

    1992-11-01

    electric tankless water heaters were laboratory tested, and five units of each type...collected. The tankless electric water heater provided a safe, sustained hot water supply, but the flow rate was lower than desirable. The average...energy cost for the tankless unit was about 26 percent lower than for the conventional electric water heater . However, the tankless electric water

  7. Water loss from the skin of term and preterm infants nursed under a radiant heater.

    Science.gov (United States)

    Kjartansson, S; Arsan, S; Hammarlund, K; Sjörs, G; Sedin, G

    1995-02-01

    The rate of evaporation from the skin (g/m2/h) was measured in 12 full-term and 16 preterm infants (gestational age 25-34 wk) both during incubator care and when nursed under a radiant heater. The method for evaporation rate measurement is noninvasive and based on determination of the water vapor pressure gradient close to the skin surface. Measurements were first made with the infant nursed in an incubator with a controlled environment with respect to humidity, temperature, and air velocity. The measurements in the term infants were performed at an ambient relative humidity (RH) of 50%, and in the preterm infants first at 50% and subsequently at 30-40%. Evaporation rate was then measured with the infant nursed under a radiant heater. In term infants, mean evaporation rate was 3.3 g/m2/h during incubator care (RH 50%) and 4.4 g/m2/h during care under the radiant heater. In preterm infants, the corresponding values were 15.5 g/m2/h in the incubator at RH 50%, 16.7 g/m2/h at RH 30-40%, and 17.9 g/m2/h under the radiant heater. It is concluded that the evaporative water loss from the skin depends on the ambient water vapor pressure, irrespective of whether the infant is nursed in an incubator or under a radiant heater. The higher rate of evaporation during care under a radiant heater is due to the lower ambient water vapor pressure and not to any direct effect of the nonionizing radiation on the skin.

  8. 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

  9. Fired heater for coal liquefaction process

    Science.gov (United States)

    Ying, David H. S.

    1984-01-01

    A fired heater for a coal liquefaction process is constructed with a heat transfer tube having U-bends at regular intervals along the length thereof to increase the slug frequency of the multi-phase mixture flowing therethrough to thereby improve the heat transfer efficiency.

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

    OpenAIRE

    Spannhake, Jan; Schulz, Olaf; Helwig, Andreas; Krenkow, Angelika; M?ller, Gerhard; Doll, Theodor

    2006-01-01

    Micromachined thermal heater platforms offer low electrical power consumption and 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 on investigations on silicon-on-insulator (SOI) based infrared (IR) emitter devices heated by employing different kinds of metallic and semiconductor heater materials. Our results clearly reveal the superior high-temperature performance of semicon...

  11. 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 ...

  12. Solar dryer with thermal storage and biomass-backup heater

    Energy Technology Data Exchange (ETDEWEB)

    Madhlopa, A. [Department of Physics and Biochemical Sciences, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi); Ngwalo, G. [Department of Mechanical Engineering, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi)

    2007-04-15

    An indirect type natural convection solar dryer with integrated collector-storage solar and biomass-backup heaters has been designed, constructed and evaluated. The major components of the dryer are biomass burner (with a rectangular duct and flue gas chimney), collector-storage thermal mass and drying chamber (with a conventional solar chimney). The thermal mass was placed in the top part of the biomass burner enclosure. The dryer was fabricated using simple materials, tools and skills, and it was tested in three modes of operation (solar, biomass and solar-biomass) by drying twelve batches of fresh pineapple (Ananas comosus), with each batch weighing about 20 kg. Meteorological conditions were monitored during the dehydration process. Moisture and vitamin C contents were determined in both fresh and dried samples. Results show that the thermal mass was capable of storing part of the absorbed solar energy and heat from the burner. It was possible to dry a batch of pineapples using solar energy only on clear days. Drying proceeded successfully even under unfavorable weather conditions in the solar-biomass mode of operation. In this operational mode, the dryer reduced the moisture content of pineapple slices from about 669 to 11% (db) and yielded a nutritious dried product. The average values of the final-day moisture-pickup efficiency were 15%, 11% and 13% in the solar, biomass and solar-biomass modes of operation respectively. It appears that the solar dryer is suitable for preservation of pineapples and other fresh foods. Further improvements to the system design are suggested. (author)

  13. Development of High Efficiency Carbon Dioxide Commercial Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Michael PETERSEN; Chad D. BOWERS; Stefan ELBEL; Pega HRNJAK

    2012-07-01

    Although heat pump water heaters are today widely accepted in both Japan and Europe, where energy costs are high and government incentives for their use exist, acceptance of such products in the US has been limited. While this trend is slowly changing with the introduction of heat pump water heaters into the residential market, but acceptance remains low in the commercial sector. The objective of the presented work is the development of a high efficiency R744 heat pump water heater for commercial applications with effective utilization of the cooling capability for air conditioning and/or refrigeration. The ultimate goal is to achieve total system COP of up to 8. This unit will be targeted at commercial use where some cooling load is typically needed year round, such as restaurants, hotels, nursing homes, and hospitals. This paper presents the performance results from the development of four R744 commercial heat pump water heater packages of approximately 35 kW and comparison to a commercially available baseline R134a unit of the same capacity and footprint. In addition, the influences of an internal heat exchanger and an enhanced evaporator on the system performance are described and recommendations are made for further improvements of the R744 system.

  14. Duct effects on the distribution of γ-rays from a mixed radiation field in an ilmenite-concrete shield

    International Nuclear Information System (INIS)

    Megahid, R.M.; Eid, A.M.

    1981-01-01

    The effects of ducts on the dose distribution of γ-rays in an ilmenite-concrete shield have been investigated using a collimated beam of neutrons and γ-rays from a reactor. Measurements were performed in a homogeneous concrete medium and repeated in a medium containing cylindrical air-filled ducts having different lengths and diameters. The γ-ray doses were measured using 7 LiF in Teflon matrix discs. The results show that the presence of ducts increases the γ-ray doses in the regions surrounding the ducts except for thicknesses less than 20 cm. This increase has a maximum value at positions located approx. 10 cm after the duct ends. The observed increase at peak positions depends on the duct diameters and vertical distances. (author)

  15. Temperature changes in contact lenses in connection with radiation from infrared heaters.

    Science.gov (United States)

    Lövsund, P; Nilsson, S E; Oberg, P A

    1979-09-01

    A number of reports have appeared over the past few years with warnings about the wearing of contact lenses in certain trades involving exposure to are flash. In view of these reports and in light of knowledge on the marked absorption by contact lenses, within the infrared (IR) region, temperature changes were measured in soft contact lenses under radiation from IR heaters used, for example, in the motor industry for drying paint. The lenses were tested while free-hanging and when applied to rabbit eyes. Great increases in temperature were noted with one of the heaters at a distance corresponding to "safe." During 10 min of exposure the temperature of a free-hanging lens rose from 21 to 59 degrees C, whereas the temperature in the surrounding air increased only from 26 to 30 degrees C. The final temperature of the lens was thus 29 degrees C higher than that of the air. In lenses applied to rabbit eyes the temperature rose within only 0.5, 1.0, and 1.5 min from approximately 33 degrees C to about 44, 49, and 51 degrees C, respectively; the air temperature rose from 25 to only 28 degrees C. In other words, the ultimate lens temperature was 23 degrees C higher than the ambient air temperature. In the rabbit experiments most of the lenses dried out completely. There would thus seem to be considerable risk of contact lenses drying and becoming adherent to and damaging the corneal surface among workers exposed to powerful radiation from IR radiators (IR heaters), unless they use efficient eye protectors. IR heaters appear to be associated with greater hazards than are flashes, since there is no warning from powerful visible light and because they are capable of causing a very rapid increase in temperature.

  16. Field Monitoring Protocol. Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Earle, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maguire, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wilson, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hancock, C. E. [Mountain Energy Partnership, Longmont, CO (United States)

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  17. Field Monitoring Protocol: Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Earle, L.; Christensen, D.; Maguire, J.; Wilson, E.; Hancock, E.

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  18. Improving Heat Pump Water Heater Effeciency by Avoiding Electric Resistance Heater Use

    Energy Technology Data Exchange (ETDEWEB)

    Boudreaux, Philip R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parkison, April E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nutaro, James J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-09-01

    Heat pump water heaters (HPWHs) are a promising technology that can decrease the domestic hot water energy consumption over an electric resistance storage water heater by up to 50%. Heat pump water heaters are really two water heaters in one; they can heat water by using a heat pump or by using electric resistance elements. During large water draw events the HPWHs will use the resistance elements that decrease the overall efficiency of the units. ORNL proposed and tested an advanced control algorithm that anticipates the large water draw events and appropriately sets-up the temperature of the tank water using only the heat pump. With sufficient energy stored in the tank at the elevated temperature, the large water draw is provided for and electric resistance use is avoided. Simulations using a validated heat pump water heater model, and measured water draw data from 25 homes, show average yearly energy savings of 9% for the advanced control algorithm. If the advanced control algorithm perfectly predicts the large water draw events then the savings increase to 19%. This discrepancy could be due to a lack of predictability of water draw patterns in some homes, or the water draw forecasting algorithm could be improved.

  19. Improved Duct Systems Task Report with StageGate 2 Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Neil [Florida Solar Energy Center, Cocoa, FL (United States); Stroer, Dennis [Calcs-Plus, Venice, FL (United States)

    2007-12-31

    This report is about Building America Industrialized Housing Partnership's work with two industry partners, Davalier Homes and Southern Energy Homes, in constructing and evaluating prototype interior duct systems. Issues of energy performance, comfort, DAPIA approval, manufacturability and cost is addressed. A stage gate 2 analysis addresses the current status of project showing that there are still refinements needed to the process of incorporating all of the ducts within the air and thermal boundaries of the envelope.

  20. 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... Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers and Process Heaters Pt. 63, Subpt. DDDDD, Table 4 Table 4 to Subpart DDDDD of Part 63—Operating Limits for Boilers and Process...

  1. 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... Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers and Process Heaters Pt. 63, Subpt. DDDDD, Table 2 Table 2 to Subpart DDDDD of Part 63—Operating Limits for Boilers and Process...

  2. A super flexible and custom-shaped graphene heater.

    Science.gov (United States)

    Zhang, Tian-Yu; Zhao, Hai-Ming; Wang, Dan-Yang; Wang, Qian; Pang, Yu; Deng, Ning-Qin; Cao, Hui-Wen; Yang, Yi; Ren, Tian-Ling

    2017-10-05

    In this paper, we fabricate a graphene film heater through laser reduction on graphene oxide, which is a two-step process. The electrothermal performance of the graphene heater can be adjusted by the laser energy density. While the applied voltage is 18 V, the graphene heater reaches a steady-state temperature of 247.3 °C within 20 s. After the graphene heater is folded in half 100 times, its output temperature remains to be precisely controlled by the input power and the temperature distribution is uniform. In addition, the flexibility of the graphene heater is superior to a heater based on a commercial indium tin oxide film. It's worth noting that the graphene heater can be fabricated with desired shapes directly and easily, which is rare among the reported film heaters. In consideration of the high performance of the graphene film heater, we demonstrate its three application scenarios: portable warmers applied in medical infusion apparatus, flexible custom-shaped heaters for special requirements and displays.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Plasma transport in magnetic duct filter

    International Nuclear Information System (INIS)

    Zhang Tao; Chu, Paul K; Fu, Ricky K Y; Brown, Ian G

    2002-01-01

    A cathodic arc plasma source equipped with a curved magnetic duct to filter macro-particles was used to study plasma transport through the duct. The optimal duct bias, at which the magnetic duct produces the maximum plasma output, for titanium cathodic arc plasma at 50, 100 and 150 A arc current was determined and the parametric effects of the arc current and guiding magnetic field on the optimal duct bias were investigated. The optimal bias decreased as the guiding magnetic field increased from 100 to 400 G and was almost independent of the guiding magnetic field when it was between 400 and 600 G, the upper limit for our equipment. The optimal duct bias at 400 G guiding magnetic field decreased with increasing arc current. Our results indicate that the optimal duct bias is related not only to the structure of the plasma source, but is also influenced by many other factors including cathode material and other plasma properties

  8. 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

  9. 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.

  10. Insulated conductor temperature limited heater for subsurface heating coupled in a three-phase WYE configuration

    Science.gov (United States)

    Vinegar, Harold J.; Sandberg, Chester Ledlie

    2010-11-09

    A heating system for a subsurface formation is described. The heating system includes a first heater, a second heater, and a third heater placed in an opening in the subsurface formation. Each heater includes: an electrical conductor; an insulation layer at least partially surrounding the electrical conductor; and an electrically conductive sheath at least partially surrounding the insulation layer. The electrical conductor is electrically coupled to the sheath at a lower end portion of the heater. The lower end portion is the portion of the heater distal from a surface of the opening. The first heater, the second heater, and the third heater are electrically coupled at the lower end portions of the heaters. The first heater, the second heater, and the third heater are configured to be electrically coupled in a three-phase wye configuration.

  11. Fluctuating pressure forces acting on the hot gas duct of a high temperature reactor

    International Nuclear Information System (INIS)

    Achenbach, E.

    1977-01-01

    In the hot gas ducts of high temperature reactors high velocities (70 0 -bends of segmental design; 90 0 -bends, mitred; 90 0 -mitred, rectangular channel. For comparison the pressure fluctuations of the straight tube were also determined. The experiments were conducted in air, pressurized air and helium. The pressure fluctuations were measured by means of condenser microphones. (Auth.)

  12. 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

  13. 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.

  14. 76 FR 63211 - Energy Efficiency Program: Test Procedures for Residential Water Heaters, Direct Heating...

    Science.gov (United States)

    2011-10-12

    ... Efficiency Program: Test Procedures for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters... residential water heaters, direct heating equipment, and pool heaters. This rulemaking is intended to fulfill... water heaters, possible clarifications and improvement of the direct heating equipment test procedures...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Measure Guideline: Transitioning to a Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Brozyna, K.; Rapport, A.

    2012-09-01

    This Measure Guideline provides information to help residential builders and retrofitters with the design, specification, selection, implementation, installation, and maintenance issues of transitioning from tank-type water heaters to tankless water heaters. The report compares the differences between tankless and tank-type water heaters, highlighting the energy savings that can be realized by adopting tankless water heaters over tank-type water heaters. Selection criteria and risks discussed include unit sizing and location, water distribution system, plumbing line length and diameter, water quality, electrical backup, and code issues. Cost and performance data are provided for various types of tankless and tank-type water heaters, both natural gas fired and electric. Also considered are interactions between the tankless water heater and other functional elements of a house, such as cold water supply and low-flow devices. Operating costs and energy use of water distribution systems for single- and two-story houses are provided, along with discussion of the various types of distribution systems that can be used with tankless water heaters. Finally, details to prepare for proper installation of a tankless water heater are described.

  1. 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.

  2. Laser microdissection of the alveolar duct enables single-cell genomic analysis

    Directory of Open Access Journals (Sweden)

    Robert eBennett

    2014-09-01

    Full Text Available Complex tissues such as the lung are composed of structural hierarchies such as alveoli, alveolar ducts and lobules. Some structural units, such as the alveolar duct, appear to selectively participate in tissue regeneration. Here, we demonstrate an approach to conduct laser microdissection of the lung alveolar duct for single-cell PCR analysis. Our approach involved three steps. 1 The initial preparation used mechanical sectioning of the lung tissue with sufficient thickness to encompass the structure of interest. In the case of the alveolar duct, the precision-cut lung slices were 200um thick; the slices were processed using near-physiologic conditions to preserve the state of viable cells. 2 The lung slices were examined by transmission light microscopy to target the alveolar duct. The air-filled lung was sufficiently accessible by light microscopy that counterstains or fluorescent labels were unnecessary to identify the alveolar duct. 3 The enzymatic and microfluidic isolation of single cells allowed for the harvest of as few as several thousand cells for PCR analysis. Microfluidics based arrays were used to measure the expression of selected marker genes in individual cells to characterize different cell populations. Preliminary work suggests the unique value of this approach to understanding the intra- and intercellular interactions within the regenerating alveolar duct.

  3. Thirsty Walls - A new paradigm for air revitalization in life support

    Data.gov (United States)

    National Aeronautics and Space Administration — Historically, air revitalization is performed by routing air through a complex set of ducts and removal beds that restrict airflow. Microgravity considerations...

  4. Fast nanotopography imaging using a high speed cantilever with integrated heater-thermometer.

    Science.gov (United States)

    Lee, Byeonghee; Somnath, Suhas; King, William P

    2013-04-05

    This paper presents a high speed tapping cantilever with an integrated heater-thermometer for fast nanotopography imaging. The cantilever is much smaller and faster than previous heated cantilevers, with a length of 35 μm and a resonant frequency of 1.4 MHz. The mechanical response time is characterized by scanning over a backward-facing step of height 20 nm. The mechanical response time is 77 μs in air and 448 μs in water, which compares favorably to the fastest commercial cantilevers that do not have integrated heaters. The doped silicon cantilever is designed with an integrated heater that can heat and cool in about 10 μs and can operate in both air and water. We demonstrate standard laser-based topography imaging along with thermal topography imaging, when the cantilever is actuated via the piezoelectric shaker in an atomic force microscope system and when it is actuated by Lorentz forces. The cantilever can perform thermal topography imaging in tapping mode with an imaging resolution of 7 nm at a scan speed of 1.46 mm s(-1).

  5. Assessing a novel contact heater as a new method of recovering explosives traces from porous surfaces.

    Science.gov (United States)

    Yu, Holly A; Lewis, Simon W; Beardah, Matthew S; NicDaeid, Niamh

    2016-02-01

    It can be very challenging to recover explosives traces from porous surfaces, such as clothing and car seats, compared to non-porous surfaces. The contact heater has been developed as a novel instrument designed to recover explosives traces from porous surfaces. Samples are taken by heating and drawing air across a surface, with the air flowing through a sampling cartridge containing adsorbent polymer beads, which act to trap any recovered explosive material. Any collected explosive can then be eluted from this cartridge using a solvent, prior to analysis. This paper outlines work performed to evaluate the usefulness of the contact heater with regards to the recovery of explosives traces from porous materials. Ethylene glycol dinitrate (EGDN) and triacetone triperoxide (TATP) were chosen as two representative explosives for this study. Quantification was performed using GC-MS for EGDN and LC-MS/MS for TATP. Different sampling temperatures, sampling times and elution solvents were investigated. Recovery was trialled from leather, carpet and denim. Recoveries of up to 71% were obtained following optimisation. It was also possible to recover TATP from fabrics exposed to TATP vapour in a vapour-laden jar up to two hours after exposure. The contact heater therefore appears to be a very useful tool for the recovery of explosives traces from porous materials. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. 75 FR 32682 - National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...

    Science.gov (United States)

    2010-06-09

    ... 2050-AG44 National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters; National Emission Standards for Hazardous Air..., Administrative practice and procedure, Air pollution control, Hazardous substances, Incorporation by reference...

  7. 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

  8. 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)

  9. Commercial Absorption Heat Pump Water Heater: Beta Prototype Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Geoghegan, Patrick [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ally, Moonis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sharma, Vishaldeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-14

    The Beta version of the Commercial Absorption Heat Pump (CAHP) water heater was evaluated in the environmental chambers at Oak Ridge National Laboratory. Ambient air conditions ranged from 17 to 75 oF and inlet water temperatures ranged from 100 to 120oF in order to capture trends in performance. The unit was operated under full fire (100%) and partial fire (55%). The unit was found to perform at 90% of the project goal at the design conditions of 47oF ambient and 100oF water temperatures. The trends across the full range of environmental conditions were as expected for ambient air temperatures above 32oF. Below this temperature and for the full fire condition, frost accumulated on the evaporator coil. In future work a defrost strategy will be enabled, the unit will be thoroughly cleaned of an oil contamination and the rectifier will be reconfigured in order to meet the design goals and have a field test unit ready in early 2017.

  10. 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)

  11. 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...

  12. Intraoperative cholangiographic findings of intrahepatic duct stones

    International Nuclear Information System (INIS)

    Kim, Mi Young; Suh, Chang Hae; Choi, Hye Ran; Ahn, Byeong Yeob; Chung, Woun Kyun; Lee, Yong

    1989-01-01

    Operative cholangiography is considered essential during biliary operation in order to minimise the chance of negative exploration and to demonstrate the anatomy and pathology of intra and extrahepatic biliary tree. Although many authors have evaluated and accepted various techniques for operative cholangiography, the image of operative cholangiography is affected mainly by intrahepatic duct stones and anatomic characteristic of biliary tree. In case of intrahepatic duct stones accurate evaluation of the operative cholangiographic findings is important for a plan of further treatment including interventional procedures. We reviewed 45 operative cholangiograms of 30 patients with intrahepatic duct stones from January,1986 to September, 1988, and analysed operative cholangiographic findings with a special attention to the correlation between cholangiographic findings and the location of intrahepatic duct stones. The results were as follows: 1. Common bile duct stones were found in 72%, and generalized cholangitis was combined in 43% of patient with intrahepatic duct stones. 2. Incomplete ductal filling of contrast media was the most frequent findings of left intrahepatic duct stones in operative cholangiograms with four different cholangiogram catheters. 3. Nonfilling and partial filling were the most frequent findings; nonfilling was prevalent in right anterior and left medial ducts, and partial filling was prevalent in left medial and left lateral ducts

  13. design and construction of a water heater controller

    African Journals Online (AJOL)

    DESIGN AND CONSTRUCTION OF A WATER HEATER CONTROLLER. ... In this design, a real time emulator driven by software controls a water heater using a micro-controller. Keywords. Micro-controller, geyser, keypad, interface, design, construction. African Journal of Science and Technology Vol.5(1) 2004: 1-5.

  14. 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.

  15. 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

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

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 8, No 1 (2016) >. Log in or Register to get access to full text downloads.

  17. 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.

  18. Laparoscopic common bile duct exploration.

    Science.gov (United States)

    Shuchleib, S; Chousleb, A; Mondragon, A; Torices, E; Licona, A; Cervantes, J

    1999-07-01

    Since the introduction of laparoscopic cholecystectomy, the management of common bile duct (CBD) stones has undergone significant change. Preoperative endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy is now routinely done in cases where the diagnosis of choledocholithiasis is suspected preoperatively, with clearance of the bile ducts before laparoscopic cholecystectomy. Intraoperative discovery of CBD stones by cholangiography represents a challenge to the surgeon, who must make a decision about when to perform laparoscopic CBD exploration, convert to open surgery, or send the patient for ERCP during the postoperative period. Because ERCP has a definite failure rate, laparoscopic CBD exploration can be a treatment option. Among 2500 laparoscopic cholecystectomies done by our group from January 1991 to June 1997, 50 patients (2%) underwent laparoscopic CBD exploration, 13 by the transcystic technique and 37 by choledocotomy, with a conversion rate of 8% and a hospital stay of 4.3 days. One patient died from complicated pancreatitis following ERCP and unsuccessful extraction of a CBD stone. We obtained our goal of a CBD free of stones in 92% of the cases. We conclude that laparoscopic CBD exploration is an effective method for treating choledocolithiasis that allows management of this pathology in one stage, although it requires advanced laparoscopic skills and adequate equipment.

  19. Measure Guideline. Sealing and Insulating Ducts in Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, S. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2011-12-01

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  20. Measure Guideline: Sealing and Insulating of Ducts in Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Puttagunta, S.

    2011-12-01

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  1. 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

  2. Persistent Mullerian Duct Syndrome with Transverse Testicular ...

    African Journals Online (AJOL)

    The Mullerian duct regresses in male due to a glycoprotein secreted by the developing testes called. Mullerian inhibiting factor (MIF). Failure to regress may be due to lack of MIF or defective MIF receptor, resulting in various disorders of regression, and one such disorder is persistent Mullerian duct syndrome (PMDS).

  3. Prostatic Duct Adenocarcinoma with Endometrioid Features: Report ...

    African Journals Online (AJOL)

    mn

    4, 2009. 257. 257-258. Case Report. Prostatic Duct Adenocarcinoma with Endometrioid. Features: Report of a Rare Case and Brief Review of the Literature ... 3. adenocarcinoma of the prostate: A distinctive tumor of probable prostatic duct origin. Cancer. 1976;. May;37(5):2255-62. Cohen RJ, Wheeler TM, Bonkhoff H, ...

  4. Calcium influx pathways in rat pancreatic ducts

    DEFF Research Database (Denmark)

    Hug, M J; Pahl, C; Novak, I

    1996-01-01

    A number of agonists increase intracellular Ca2+ activity, [Ca2+]i, in pancreatic ducts, but the influx/efflux pathways and intracellular Ca2+ stores in this epithelium are unknown. The aim of the present study was to characterise the Ca2+ influx pathways, especially their pH sensitivity, in native...... pathways in pancreatic ducts cells....

  5. 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

  6. Salivary Duct Cyst: Histo-pathologic Correlation

    Directory of Open Access Journals (Sweden)

    Divya Vinayachandran

    2013-01-01

    Full Text Available Non-neoplastic cysts of the salivary glands are uncommon and represent 2-5% of all salivary gland lesions. They are mainly mucoceles or salivary duct cysts. Unlike a mucocele, which is surrounded by granulation tissue, the salivary duct cyst is lined by epithelium. Salivary duct cysts are more common in the oral minor salivary glands and rarely occur in the major salivary glands, show a marked predilection for the superficial lobe of the parotid, and represent 10% of all salivary gland cysts. Neoplastic differentiation of the lining of the salivary duct cyst has been reported. We report a case of a salivary duct cyst of the left parotid gland, with a review of radiographic and histopathologic features.

  7. Integrity Assessment of GOH Heater Tube

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Sang; Hong, J. H.; Oh, Y. J.; Yoon, J. H.; Oh, J. M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-08-01

    An assessment of structural integrity of ASTM A312-TP347 GOH heater tube was performed. The surface notches which had been produced during tube manufacturing process were analyzed microscopically. Chemical analysis, hardness tests, tensile tests, and J-Integral fracture resistance tests were carried out to compare the mechanical properties with those of the material specification and also with the other material of the same type. The test results showed the mechanical properties of the GOH tube material are within the specification range. An elastic-plastic fracture mechanics analysis based on the DPFAD method reveals the tube an appropriate safety margin for the normal operation. 13 refs., 5 tabs., 24 figs. (author)

  8. Fluid bed solids heater. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Preuit, L. C.

    1980-01-01

    A solids heater which operates at up to 2000 F was designed, fabricated, installed and operated through checkout at the Morgantown Energy Technology Center at Morgantown, West Virginia. The system, designated the 2000 F Fluid Bed Solids Heater (FBSH) uses a fluidized bed to heat limestone to 600 F and aluminium oxide or silicon carbide to 2000 F and discharges heated solids upon demand. The FBSH with added valve handling and pressurization equipment is known as the Valve Hot Solids Test Unit and is intended for use by the US Department of Energy for testing of valves for severe service applications in coal conversion and utilization processes. The FBSH as designed and supplied by Combustion Power Company includes process equipment, controls, the enclosing building and other associated equipment. In the 600 F range of operation it can circulate limestone through two valve test trains simultaneously on a continuous basis. Only one valve test train is used for 2000 F solids and operation in that range is also continuous. Limestone, crushed to minus 5/16 size, is heated, discharged, and recycled at a maximum average rate of 250 lb/min while aluminum oxide or silicon carbide, No. 8 grit, is circulated at rates up to 167 lb/min. The FBSH control system is designed for automatic operation, and capability is included for external computerized data acquisition and/or supervisory control. An operating and maintenance manual and as-built drawings have been submitted. This report describes the FBSH equipment, its design basis, and its operation. It has been prepared and submitted in fulfillment of Contract Number DIAC05-77ET10499.

  9. 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.

  10. 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.

  11. Field investigation of duct system performance in California light commercial buildings

    Energy Technology Data Exchange (ETDEWEB)

    Delp, W.W.; Matson, N.E.; Tschudy, E. [and others

    1997-12-09

    This paper discusses field measurements of duct system performance in fifteen systems located in eight northern California buildings. Light commercial buildings, one- and two-story with package roof-top HVAC units, make up approximately 50% of the non-residential building stock in the U.S. Despite this fact little is known about the performance of these package roof-top units and their associated ductwork. These simple systems use similar duct materials and construction techniques as residential systems (which are known to be quite leaky). This paper discusses a study to characterize the buildings, quantify the duct leakage, and analyze the performance of the ductwork in these types of buildings. The study tested fifteen systems in eight different buildings located in northern California. All of these buildings had the ducts located in the cavity between the drop ceiling and the roof deck. In 50% of these buildings, this cavity was functionally outside the building`s air and thermal barriers. The effective leakage area of the ducts in this study was approximately 2.6 times that in residential buildings. This paper looks at the thermal analysis of the ducts, from the viewpoint of efficiency and thermal comfort. This includes the length of a cycle, and whether the fan is always on or if it cycles with the cooling equipment. 66% of the systems had frequent on cycles of less than 10 minutes, resulting in non-steady-state operation.

  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.; 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%.

  13. Air

    CERN Document Server

    Rivera, Andrea

    2017-01-01

    Air is all around us. Learn how it is used in art, technology, and engineering. Five easy-to-read chapters explain the science behind air, as well as its real-world applications. Vibrant, full-color photos, bolded glossary words, and a key stats section let readers zoom in even deeper. Aligned to Common Core Standards and correlated to state standards. Abdo Zoom is a division of ABDO.

  14. 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

  15. 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.

  16. Substrate heater for the growth of epitaxial silicon films

    Science.gov (United States)

    Deming, Matthew; Varhue, Walter; Adams, Edward; Lavoie, Mark

    1999-03-01

    The single wafer processing of epitaxial Si films requires that special attention be paid to the design of the substrate heater assembly. This document describes the evolution and testing of an in situ heater used to deposit epitaxial Si films at temperatures as high as 700 °C. One problem encountered was the production of excessive levels of ultraviolet radiation which contributed to the desorption of water vapor from the vacuum chamber walls during the in situ cleaning process. A second problem involved the formation of a molybdenum containing film that poisoned epitaxial growth. A final proven in situ heater design is presented which avoids these problems.

  17. Design and Implementation of the MSL Cruise Propulsion Tank Heaters

    Science.gov (United States)

    Krylo, Robert; Mikhaylov, Rebecca; Cucullu, Gordon; Watkins, Brenda

    2008-01-01

    This slide presentation reviews the design and the implementation of the heaters for the Mars Science Laboratory (MSL). The pressurized tanks store hydrazine that freezes at 2 C, this means that heaters are required to keep the hydrazine and the helium at 36 C for the trip to Mars. Using the TMG software the heat loss was analyzed, and a thermal model simulates a half full tank which yielded a 13W heating requirement for each hemisphere. Views of the design, and the heater are included.

  18. Friction coefficient measurements of silencers on specialized duct tract

    Directory of Open Access Journals (Sweden)

    Sehnalek Stanislav

    2016-01-01

    Full Text Available This article describes test methods on air duct track in Laboratory of Environmental Engineering. It focuses on measurement of silencer parameter like is pressure loss coeffcient. Firstly, the paper describe the measurement apparatus with description of calculation method by standard ISO 7235 and energy equation. Then the paper presents three ways how to accomplish measurement because such way is not covered by procedure in standard. Then follows the evaluation of results of measurements on three types of silencer designed for HVAC applications. The article is concluded with discussion over measured data with outline for further research.

  19. Conjugate heat and mass transfer in heat mass exchanger ducts

    CERN Document Server

    Zhang, Li-Zhi

    2013-01-01

    Conjugate Heat and Mass Transfer in Heat Mass Exchanger Ducts bridges the gap between fundamentals and recent discoveries, making it a valuable tool for anyone looking to expand their knowledge of heat exchangers. The first book on the market to cover conjugate heat and mass transfer in heat exchangers, author Li-Zhi Zhang goes beyond the basics to cover recent advancements in equipment for energy use and environmental control (such as heat and moisture recovery ventilators, hollow fiber membrane modules for humidification/dehumidification, membrane modules for air purification, desi

  20. 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

  1. 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...

  2. 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...

  3. 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.

  4. Air

    International Nuclear Information System (INIS)

    Gugele, B.; Scheider, J.; Spangl, W.

    2001-01-01

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  5. 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.

  6. [Salivary gland drainage into the thyroglossal duct].

    Science.gov (United States)

    Siem, G; Natvig, K; Kolbenstvedt, A; Lømo, J

    2001-01-20

    Failure in regression of the thyroglossal duct is one of the most common reasons for midline swellings in the neck. Several authors have described recurrent thyroglossal duct remnants with persisting draining sinuses. However, few have described accessory salivary glands that drain into the thyroglossal duct. In this article we report two such cases with midline salivary glands in the floor of the mouth. These two patients were subsequently successfully treated with radical tissue resection in the area between the hyoid bone and foramen cecum. Preoperative fistulography or sinography was useful to demonstrate the ductal ramification of the salivary glands, and use of methylene blue during surgery proved of significant value for the result.

  7. 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)

  8. A High Performance Cathode Heater for Hall Thrusters, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The current state-of-the-art co-axial swaged tantalum (Ta) heaters use magnesium oxide (MgO) insulators, which limits their operation to temperatures well below...

  9. Thermometry of a high temperature high speed micro heater.

    Science.gov (United States)

    Xu, M; Slovin, G; Paramesh, J; Schlesinger, T E; Bain, J A

    2016-02-01

    A high temperature high-speed tungsten micro heater was fabricated and tested for application in phase change switches to indirectly heat and transform phase change material. Time domain transmissometry was used to measure heater temperature transients for given electrical inputs. Finite element modeling results on heater temperature transients show a good consistency between experiments and simulations with 0.2% mismatch in the best case and 13.1% in the worst case. The heater described in this work can reliably reach 1664 K at a rate of 1.67 × 10(10) K/s and quench to room temperature with a thermal RC time constant (time for T to fall by a factor of e) of less than 40 ns.

  10. Electron beam irradiated silver nanowires for a highly transparent heater.

    Science.gov (United States)

    Hong, Chan-Hwa; Oh, Seung Kyu; Kim, Tae Kyoung; Cha, Yu-Jung; Kwak, Joon Seop; Shin, Jae-Heon; Ju, Byeong-Kwon; Cheong, Woo-Seok

    2015-12-07

    Transparent heaters have attracted increasing attention for their usefulness in vehicle windows, outdoor displays, and periscopes. We present high performance transparent heaters based on Ag nanowires with electron beam irradiation. We obtained an Ag-nanowire thin film with 48 ohm/sq of sheet resistance and 88.8% (substrate included) transmittance at 550 nm after electron beam irradiation for 120 sec. We demonstrate that the electron beam creates nano-soldering at the junctions of the Ag nanowires, which produces lower sheet resistance and improved adhesion of the Ag nanowires. We fabricated a transparent heater with Ag nanowires after electron beam irradiation, and obtained a temperature of 51 °C within 1 min at an applied voltage of 7 V. The presented technique will be useful in a wide range of applications for transparent heaters.

  11. 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

  12. New Home Buyer Solar Water Heater Trade-Off Study

    International Nuclear Information System (INIS)

    Symmetrics Marketing Corporation

    1999-01-01

    This report details the results of a research conducted in 1998 and 1999 and outlines a marketing deployment plan designed for businesses interested in marketing solar water heaters in the new home industry

  13. Regulated heater and controller for safe, rapid warming of helium Dewars

    International Nuclear Information System (INIS)

    Mueller, R.M.; Ihas, G.G.; Adams, E.D.

    1982-01-01

    A 120-W heater and its control circuit for the safe warming of a helium Dewar to room temperature are described. The controller senses the temperature of the heater by a thermistor attached to it and shuts the heater off when it is just above room temperature. In the case of a dangerous malfunction, a meltable link mounted on the heater opens the electrical circuit when the heater reaches 61 0 C

  14. Replacement of the condenser necked feedwater heaters for nuclear power plant

    International Nuclear Information System (INIS)

    Shimada, A.; Yamaguchi, H.; Kimura, M.; Ooshima, Y.; Nakashima, Y.; Ogawa, K.; Akiba, T.; Hoshi, T.

    2008-01-01

    In Fukushima Daiichi Nuclear Power Station Unit 2, the feedwater heaters, which were placed in the condenser neck, were replaced in 2006. Many feedwater heaters had been replaced in BWR plants, but, only a few condenser necked heaters were replaced. As the necked heaters were large-scale and placed in the condenser, various technical problems should be solved for replacing. This report shows some solutions applied in the condenser necked feedwater heater replacement. (author)

  15. 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.

  16. Traumatic resin ducts as indicators of bark beetle outbreaks

    Science.gov (United States)

    R. Justin DeRose; Matthew F. Bekker; James N. Long

    2017-01-01

    The formation of traumatic resin ducts (TRDs) represents an important induced defense in woody plants that enhances oleoresin production and flow in response to environmental perturbations. In some genera (Pinus), resin ducts are copious and conspicuous; however, in others (Picea), resin ducts are relatively rare. The occurrence and strength of resin ducts, in...

  17. 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

  18. 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.

  19. 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

  20. Primary hepatocellular carcinoma in extrahepatic bile duct

    International Nuclear Information System (INIS)

    Jeong, Seok Tae; Ham, Soo Youn; Park, Cheol Min; Kim, Jung Hyuk; Cha, In Ho; Chung, Kyoo Byung; Suh, Woon Hyuck; Lee, Chang Hong

    1991-01-01

    Obstructive jaundice due to hepatocellular carcinoma in an extrahepatic bile duct, without a mass lesion in the liver parenchyma, is extremely rare. We experienced two cases of primary hepatocellular carcinoma arising from an extrahepatic bile duct: one in a 53-year-old man whose α -fetoprotein value was 800 ng/ml, and another in a 39-year-old woman, in whom the mass lesion was found to be attached to an extrahepatic bile duct. These tumors had a well-marginated sausage-like shape on CT and US, and the contrast media passed freely along their margins on both PTC and ERCP. Recurrences of these tumors were observed in the extrahepatic bile duct 6 and 2 months after surgery, respectively

  1. Unusually large sialolith of Wharton's duct

    Science.gov (United States)

    Iqbal, Ali; Gupta, Anup K.; Natu, Subodh S.; Gupta, Atul K.

    2012-01-01

    The formation of calcific concretions in the salivary duct or glands is a common disorder, especially in the submandibular glands. Most of the salivary calculi are small in size, in contrast to those that reach several centimeters, which are reported as megaliths or giant calculi in the literature. They may occur in any of the salivary gland ducts but are most common in Wharton's duct and the submandibular gland. This report presents clinical and radiographical sign of an unusually large sialolith. There was painless swelling on the floor of the edentulous mouth and patient was unaware of it. Radiographical examination revealed large irregular radio-opaque mass superimposed on right canine and premolar areas. This case report describes a patient presenting with an unusually large submandibular gland duct sialolith, the subsequent patient management, the aetiology, diagnosis and its treatment. PMID:23483770

  2. 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

  3. 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

  4. 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

  5. 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

  6. Error analysis for duct leakage tests in ASHRAE standard 152P

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.

    1997-06-01

    This report presents an analysis of random uncertainties in the two methods of testing for duct leakage in Standard 152P of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). The test method is titled Standard Method of Test for Determining Steady-State and Seasonal Efficiency of Residential Thermal Distribution Systems. Equations have been derived for the uncertainties in duct leakage for given levels of uncertainty in the measured quantities used as inputs to the calculations. Tables of allowed errors in each of these independent variables, consistent with fixed criteria of overall allowed error, have been developed.

  7. 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.

  8. 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/

  9. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation; Weitzel, E. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation

    2017-03-03

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  10. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-03-01

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  11. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2013-11-22

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  12. 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...

  13. Enucleation or exenteration in two dogs with previous parotid duct transposition: parotid duct ligation versus reverse parotid duct transposition.

    Science.gov (United States)

    Young, Whitney M; Betbeze, Caroline M; Fisher, Stephen C; Boulay, James P

    2017-08-27

    Two dogs with previous parotid duct transpositions presented with unrelated ocular disease. In both cases, ophthalmic examination revealed the need for enucleation or exenteration. In case 1, systemic coccidioidomycosis was diagnosed with panuveitis and secondary glaucoma of the left eye. In this case, the parotid duct was ligated at the time of enucleation to stop salivary secretions. This dog encountered morbidity in the form of a sialocele that did not resolve for 11 months. In case 2, ultrasound and computed tomography revealed a discrete mass within the left medial orbit that was suspected to arise from the nictitating membrane. A combination of exenteration and parotid duct transposition reversal was performed to avoid morbidity associated with ligation of the parotid duct. The dog encountered no complications from this novel procedure. This case report represents the first report of re-routing a transposed parotid duct from the ventral conjunctival sac back to the mouth at the time of enucleation or exenteration in the dog. © 2017 American College of Veterinary Ophthalmologists.

  14. Ultrasound appearance of chronic mammary duct ectasia

    Energy Technology Data Exchange (ETDEWEB)

    Duchesne, N. [Ottawa Hospital, Dept. of Radiology, Ottawa, Ontario (Canada)]. E-mail: nathalie_duchesne_22@yahoo.ca; Skolnik, S. [Univ. of Toronto, Dept. of Family Medicine, Toronto, Ontario (Canada); Bilmer, S. [Ottawa Hospital, Dept. of Radiology, Ottawa, Ontario (Canada)

    2005-12-15

    Mammary duct ectasia (MDE), also called periductal mastitis, mammary dysplasia, or plasma cell mastitis, is a benign condition of the mammary gland first described by Haagensen in 1951. The etiology of MDE is unknown and its pathogenesis still controversial; the periductal inflammation could be either the cause or the result of dilated damaged ducts. The process is usually bilateral and asymptomatic, with only a small percentage of patients presenting with symptoms that may include long course of tumour formation, usually subareolar breast lumps, nipple discharge, nipple retraction, mastalgia, and mammary abscess or fistulas. Mammographic presentation of MDE is well known; its features include periductal calcification, benign intraductal calcification, and retroareolar duct dilatation. The periductal calcification results from dystrophic calcification and forms calcified rings or very dense, oval, elongated calcifications, each with a central lucency representing the dilated duct. Intraductal calcifications of duct ectasia represent inspissated intraductal material and are typically of uniform high density, often needle-like, and occasionally branching. Occasionally, there are no mammographic findings, and the diagnosis must rely on sonographic features. Appearance of MDE on ultrasonography (US) depends on the stage of the disease and the contents of the dilated ducts. The acute presentation has been demonstrated in the literature more often than has its chronic counterpart. In the former, duct content can vary from anechoic to isoechoic with surrounding fatty tissue. In chronic MDE, episodes of inflammation are longer. This tends to result in secretions that have a more solid, cheesy texture, partly due to cholesterol crystals, foam cells, and inflammatory cells. For both types of MDE, the appearance can mimic high-grade ductal carcinoma in situ (DCIS) on US. In this essay, 2 chronic MDE cases are presented and their US appearance discussed. Our goal is to explore

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

    OpenAIRE

    Czerski, Grzegorz; Strugała, Andrzej

    2014-01-01

    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 calcu...

  16. 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.

  17. 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

  18. Analysis of the performance and space conditioning impacts of dedicated heat pump water heaters

    Science.gov (United States)

    Morrison, L.; Swisher, J.

    The development and testing of the newly-marketed dedicated heat pump water heater (HPWH) are described. This system utilizes an air-to-water heat pump, costs about $1,000 installed, and obtains a coefficient of performance (COP) of about 2.0 in laboratory and field tests. To investigate HPWH performance and space conditioning impacts, a simulation was developed to mode the thermal performance of a residence with resistance baseboard heat, air conditioning, and either heat pump or resistance water heating. The building characteristics are adapted for three U.S. geographical areas (Madison, Wisconsin; Washington, D.C.; and Ft. Worth, Texas), and the system is simulated for a year with typical weather data. The thermal network includes both a house node and a basement node so that the water heating equipment can be simulated in an unconditioned basement in Northern cities and in a conditioned first-floor utility room in Southern cities.

  19. 24 CFR 3280.715 - Circulating air systems.

    Science.gov (United States)

    2010-04-01

    ... applied only to surfaces that are dry and dust-, dirt-, oil-, and grease-free. Tapes and mastic closure..., Factory Made Air Ducts and Connectors. Air supply terminal devices (registers) when installed in kitchen...

  20. 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.

  1. Air conditioner in reactor container

    International Nuclear Information System (INIS)

    Nishiyama, Kunio; Yamazaki, Toshihiko.

    1978-01-01

    Purpose: To provide the subject air conditioner wherein cooled gas is blown to circulate in the direction from the bottom part toward the top part within a reactor container thereby making uniform the atmospheric temperature within the vessel and suppressing the same to a temperature below the predetermined temperature. Constitution: At the bottom part of a pressure containment vessel (PCV) are provided a plurality of fan coil units provided with heat exchangers and blowers for cooling gas within the PCV at predetermined intervals. Gas which has been cooled in these units and delivered therefrom is introduced through a connecting air duct into an annular blow-off air duct, and blown out of blow-off ports provided at equal intervals on the upper surface of the air duct. The thus blown off gas is subjected to heat exchange within the PCV, and thereafter sucked up through suction ports formed on the upper and lower surfaces of the annular suction air duct provided at the lower part of the partition plate, thus the gas being circulated to the fan coil units by means of connecting air ducts. (Yoshino, Y.)

  2. 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.

  3. Highly integrated synthesis of heterogeneous nanostructures on nanowire heater array.

    Science.gov (United States)

    Jin, Chun Yan; Yun, Jeonghoon; Kim, Jung; Yang, Daejong; Kim, Dong Hwan; Ahn, Jae Hyuk; Lee, Kwang-Cheol; Park, Inkyu

    2014-11-06

    We have proposed a new method for the multiplexed synthesis of heterogeneous nanostructures using a top-down fabricated nanowire heater array. Hydrothermally synthesized nanostructures can be grown only on the heated nanowire through nanoscale temperature control using a Joule heated nanowire. We have demonstrated the selective synthesis of zinc oxide (ZnO) nanowires and copper oxide (CuO) nanostructures, as well as their surface modification with noble metal nanoparticles, using a nanowire heater array. Furthermore, we could fabricate an array of heterogeneous nanostructures via Joule heating of individual nanowire heaters and changing of the precursor solutions in a sequential manner. We have formed a parallel array of palladium (Pd) coated ZnO nanowires and gold (Au) coated ZnO nanowires, as well as a parallel array of ZnO nanowires and CuO nanospikes, in the microscale region by using the developed method.

  4. Percutaneous electrohydraulic lithotripsy of bile duct stones

    International Nuclear Information System (INIS)

    Juliani, E.; Righi, D.; Cesarani, F.; Regge, D.; Gandini, G.

    1988-01-01

    The results are reported of percutaneous transhepatic tratment with an electrohydraulic stone disintegrator in 4 cases of bile duct lithiasis. An electri discharge, generated by a bipolar electrode, gives origin to high-amplitude and low-frequency shoc waves in the fluid medium-which cause the stone to fragment. Complete resolution of lithiasis was obtained in 2 patients with intrahepatic calculosis. In the other 2 cases of massive lithiasis of intra and extrahepatic bile ducts the treatment, however incomplete, proved to be useful, as the biliary flux was reabilitated and clinical symptoms disappeared. No relevant immediate side-effects were observed, except for well-tolerated pain during the discharges, and transitory hemobilia which solved spontaneously. No complications were observed in this series of patients. Electrohydraulic lithotripsy proves thus to be useful for supporting standard interventional radiology techniques in very complex cases of intra and extrahepatic bile duct stones

  5. Xylometazoline hydrochloride nasal spray combined with laser artificial nasolacrimal duct implantation for nasolacrimal duct obstruction

    Directory of Open Access Journals (Sweden)

    Xiao-Zhao Yang

    2017-02-01

    Full Text Available AIM: To study the role of xylometazoline hydrochloride nasal spray in combination therapy of nasolacrimal duct obstruction and to investigate the effect of nasal inflammation on nasolacrimal duct obstruction. METHODS: Totally 279 patients with nasolacrimal duct obstruction were collected, who received lacrimal passage irrigation, CT angiography for lacrimal passage and nasal endoscope before treated by lacrimal laser forming and artificial nasolacrimal duct implantation combined with xylometazoline hydrochloride nasal spray. In group A, 137 patients were treated with antibiotic eye drop and non-steroidal anti-inflammatory drugs after operations. In group B, 142 patients were treated with xylometazoline hydrochloride nasal spray besides the same treatment for group A. RESULTS:In the 279 patients 217(77.8%, in which 105 cases(76.6%were in group A and 112 cases(78.9%were in group B, were suffered with nasal inflammation, including nasal mucosal hyperemia, inferior turbinate hypertrophy, middle turbinate hypertrophy. At 3mo after the ducts were drawn, efficacy of group B was 95.8%, which was significant better than that of group A(86.1%, PCONCLUSION: Nasal inflammation was an important factor in the incidence of nasolacrimal duct obstruction, which shoud pay more attention in the process of diagnosis and treatment. Combination therapy could improve the cure rate of nasolacrimal duct obstruction.

  6. Percutaneous treatment of benign bile duct strictures

    Energy Technology Data Exchange (ETDEWEB)

    Koecher, Martin [Department of Radiology, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic)]. E-mail: martin.kocher@seznam.cz; Cerna, Marie [Department of Radiology, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Havlik, Roman [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Kral, Vladimir [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Gryga, Adolf [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Duda, Miloslav [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic)

    2007-05-15

    Purpose: To evaluate long-term results of treatment of benign bile duct strictures. Materials and methods: From February 1994 to November 2005, 21 patients (9 men, 12 women) with median age of 50.6 years (range 27-77 years) were indicated to percutaneous treatment of benign bile duct stricture. Stricture of hepatic ducts junction resulting from thermic injury during laparoscopic cholecystectomy was indication for treatment in one patient, stricture of hepaticojejunostomy was indication for treatment in all other patients. Clinical symptoms (obstructive jaundice, anicteric cholestasis, cholangitis or biliary cirrhosis) have appeared from 3 months to 12 years after surgery. Results: Initial internal/external biliary drainage was successful in 20 patients out of 21. These 20 patients after successful initial drainage were treated by balloon dilatation and long-term internal/external drainage. Sixteen patients were symptoms free during the follow-up. The relapse of clinical symptoms has appeared in four patients 9, 12, 14 and 24 months after treatment. One year primary clinical success rate of treatment for benign bile duct stricture was 94%. Additional two patients are symptoms free after redilatation (15 and 45 months). One patient is still in treatment, one patient died during secondary treatment period without interrelation with biliary intervention. The secondary clinical success rate is 100%. Conclusion: Benign bile duct strictures of hepatic ducts junction or biliary-enteric anastomosis are difficult to treat surgically and endoscopically inaccessible. Percutaneous treatment by balloon dilatation and long-term internal/external drainage is feasible in the majority of these patients. It is minimally invasive, safe and effective.

  7. Percutaneous treatment of benign bile duct strictures

    International Nuclear Information System (INIS)

    Koecher, Martin; Cerna, Marie; Havlik, Roman; Kral, Vladimir; Gryga, Adolf; Duda, Miloslav

    2007-01-01

    Purpose: To evaluate long-term results of treatment of benign bile duct strictures. Materials and methods: From February 1994 to November 2005, 21 patients (9 men, 12 women) with median age of 50.6 years (range 27-77 years) were indicated to percutaneous treatment of benign bile duct stricture. Stricture of hepatic ducts junction resulting from thermic injury during laparoscopic cholecystectomy was indication for treatment in one patient, stricture of hepaticojejunostomy was indication for treatment in all other patients. Clinical symptoms (obstructive jaundice, anicteric cholestasis, cholangitis or biliary cirrhosis) have appeared from 3 months to 12 years after surgery. Results: Initial internal/external biliary drainage was successful in 20 patients out of 21. These 20 patients after successful initial drainage were treated by balloon dilatation and long-term internal/external drainage. Sixteen patients were symptoms free during the follow-up. The relapse of clinical symptoms has appeared in four patients 9, 12, 14 and 24 months after treatment. One year primary clinical success rate of treatment for benign bile duct stricture was 94%. Additional two patients are symptoms free after redilatation (15 and 45 months). One patient is still in treatment, one patient died during secondary treatment period without interrelation with biliary intervention. The secondary clinical success rate is 100%. Conclusion: Benign bile duct strictures of hepatic ducts junction or biliary-enteric anastomosis are difficult to treat surgically and endoscopically inaccessible. Percutaneous treatment by balloon dilatation and long-term internal/external drainage is feasible in the majority of these patients. It is minimally invasive, safe and effective

  8. Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

    Directory of Open Access Journals (Sweden)

    Valeria Toffoli

    2013-12-01

    Full Text Available 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.

  9. Salivary duct carcinoma of the palate

    Directory of Open Access Journals (Sweden)

    Ponniah I

    2005-01-01

    Full Text Available Salivary duct carcinoma is a rare high-grade neoplasm that more frequently affects the parotid gland. Though neoplasms of this type are infrequent in minor salivary glands, they are less aggressive and may lead to early diagnosis before distant metastases could occur. Salivary duct carcinoma is also the most frequent epithelial component of carcinosarcoma. The present article reports a case of SDC of the palate in a 26-year-old male and discusses SDC as a malignant epithelial component in carcinosarcoma.

  10. 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

  11. 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.

  12. 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.

  13. 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...

  14. Marketers across the U. S. find propane water heaters a viable load-builder

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    Rather than the usual annual update reporting on specific models and upgrades from water heater manufacturers, the authors concentrate on water heater marketing in the propane industry. Some of the marketing strategies they present are the result of exclusive interviews and some are recaps of water heater marketing plans mentioned in the AFRED study, but marketers across the country are unanimous in their appreciation of the lowly water heater.

  15. 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

  16. Savings on natural gas consumption by doubling thermal efficiencies of balanced-flue space heaters

    Energy Technology Data Exchange (ETDEWEB)

    Juanico, Luis E. [Conicet, and Centro Atomico Bariloche e Instituto Balseiro, Av. Bustillo 9500, 8400 Bariloche, Rio Negro (Argentina); Gonzalez, Alejandro D. [Grupo de Estudios Ambientales, Instituto de Investigaciones en Biodiversidad y Medio Ambiente (Inibioma-Conicet), 8400 Bariloche, Rio Negro (Argentina)

    2008-07-01

    Natural gas is a relatively clean fossil fuel for space heating. However, when it is not used efficiently high consumption can become an environmental problem. In Argentina, individual balanced-flue space heaters are the most extensively used in temperate and cold regions. This furnace is a simple device with a burner set into a metal chamber, separated from the indoor ambient by an enclosing cabinet, and both inlet and outgas chimneys are connected to the outdoor ambient. In previous studies, we measured the performance of these commercial devices, and found very low thermal efficiency (in the range of 39-63% depending on the chimney configuration). The extensive use of these devices is possible due to the availability of unlimited amount of subsidised natural gas to households and businesses. In the present work, we developed a prototype with simple and low cost modifications made on commercial models, and measured the improvements on the thermal efficiency. Findings showed better infrared radiation, enhanced indoor air convection, and passive chimney flow regulation leading to thermal efficiency in the range of 75-85%. These values represent an improvement of 100% when compared to marketed models, and hence, the specific cost of the heater per unit of useful heating power delivered was actually reduced. Considering the large market presence of these furnaces in both residential and business sectors in Argentina, the potential benefits related to gas consumption and environmental emissions are very significant. (author)

  17. 75 FR 52892 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

    Science.gov (United States)

    2010-08-30

    ... for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters AGENCY: Office of Energy... ``Energy Conservation Program for Consumer Products Other Than Automobiles,'' including residential water... energy consumption, and because off mode is not applicable to water heaters, no amendment is required...

  18. 77 FR 74559 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

    Science.gov (United States)

    2012-12-17

    ... Energy (DOE) is amending its test procedures for residential water heaters, direct heating equipment (DHE... procedures for residential water heaters include a full- year accounting of energy use, both electricity and... water heaters already account for standby mode and off mode energy consumption. III. Discussion In the...

  19. Mountain Plains Learning Experience Guide: Appliance Repair. Course: Heater-Type Appliances.

    Science.gov (United States)

    Ziller, T.

    One of two individualized courses included in an appliance repair curriculum (see CE 027 767), this course covers minor and major heater-type appliances. The course is comprised of six units: (1) Irons, (2) Roasters, (3) Space Heaters, (4) Water Heaters, (5) Electric Ranges, and (6) Gas Ranges. Each unit begins with a Unit Learning Experience…

  20. 49 CFR 392.67 - Heater, flame-producing; on commercial motor vehicle in motion.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Heater, flame-producing; on commercial motor... SAFETY REGULATIONS DRIVING OF COMMERCIAL MOTOR VEHICLES Prohibited Practices § 392.67 Heater, flame-producing; on commercial motor vehicle in motion. No open flame heater used in the loading or unloading of...

  1. 46 CFR 61.30-5 - Preparation of thermal fluid heater for inspection and test.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Preparation of thermal fluid heater for inspection and... ENGINEERING PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-5 Preparation of thermal fluid heater for inspection and test. For visual inspection, access plates and manholes...

  2. 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.

  3. TOTAL PARTICLE, SULFATE, AND ACIDIC AEROSOL EMISSIONS FROM KEROSENE SPACE HEATERS

    Science.gov (United States)

    Chamber studies were conducted on four unvented kerosene space heaters to assess emissions of total particle, sulfate, and acidic aerosol. The heaters tested represented four burner designs currently in use by the public. Kerosene space heaters are a potential source of fine part...

  4. 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.

  5. Solitary intrahepatic bile-duct cyst presenting with Jaundice

    International Nuclear Information System (INIS)

    Park, Jeong Mi; Chun, Ki Sung; Ha, Hyun Kwon; Shinn, Kyung Sub; Bahk, Yong Whee; Kim, Jun Gi

    1989-01-01

    Caroli's disease is an uncommon condition, and characterized by congenital segmental saccular dilatation of intrahepatic bile ducts. A case of Caroli's disease, manifested by only a large communicating cystic dilatation of left intrahepatic bile duct and causing extrinsic pressure over the extrahepatic bile duct, is presented. The patient was 43-year-old housewife, hospitalized because of abdominal distension and severe jaundice. To relieve jaundice and alleviate surgical intervention, percutaneous drainage of the bile-duct cyst preceded surgery

  6. Mechanisms of Lower Bile Duct Stricture in Autoimmune Pancreatitis

    OpenAIRE

    Watanabe, Takayuki; Maruyama, Masahiro; Ito, Tetsuya; Maruyama, Masafumi; Muraki, Takashi; Hamano, Hideaki; Arakura, Norikazu; Hasebe, Osamu; Kawa, Shigeyuki

    2014-01-01

    Objectives We attempted to clarify the mechanism underlying lower bile duct stricture in autoimmune pancreatitis. Methods Imaging and histologic finding of the bile duct were assessed for 73 patients with autoimmune pancreatitis to clarify whether IgG4-related biliary inflammation or pancreatic head swelling is associated with lower bile duct stricture. Results Lower bile duct stricture was found in 59 (81%) patients. Pancreatic head swelling was significantly more frequent among patients wit...

  7. 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.

  8. ACCESSORY CYSTIC DUCT IDENTIFIED IN LAPAROSCOPIC CHOLECYSTECTOMY: A RARE CASE

    OpenAIRE

    Kumar; Kumar; Shaleen; Wasif; Amit

    2014-01-01

    We report the case of a 53 year old lady who underwent laparoscopic cholecystectomy and was found to have an accessory cystic duct close to the fundus. Careful dissection of the liver bed was done and the duct clipped preventing a bile leak. The presence of such ducts though rare should be identified during surgery to prevent potential complications.

  9. Persistent Mullerian Duct Syndrome (PMDS With Large Intraabdominal Seminoma

    Directory of Open Access Journals (Sweden)

    Della Harigovind

    2017-07-01

    Full Text Available Persistent Mullerian Duct Syndrome, a form of male pseudohermaphroditism is characterized by the presence of the Mullerian duct derivatives in an otherwise phenotypically as well as genotypically normal male. We report a case of large intra abdominal seminoma in a male patient with cryptorchidism, along with persistence of Mullerian duct derivatives (uterus.

  10. A case of fascioliasis in common bile duct

    International Nuclear Information System (INIS)

    Ham, Soo Youn; Park, Cheol Min; Chung, Kyu Byung; Lee, Chang Hong; Park, Seung Chul; Choi, Sang Yong; Lim, Han Jong

    1989-01-01

    A case of Fascioliasis of common bile duct is confirmed by visualization of adult fluke. Fascioliasis caused by Fasciola hepatica, is common parasitic disease in cattle and sheep. Human is an accidental host. ERCP demonstrated irregular linear conglomerated filling defects in common bile duct. Through surgical intervention, we found adult flukes of F. hepatica and adenomatous hyperplasia of common bile duct

  11. A case of fascioliasis in common bile duct

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Soo Youn; Park, Cheol Min; Chung, Kyu Byung; Lee, Chang Hong; Park, Seung Chul; Choi, Sang Yong; Lim, Han Jong [Korea University College of Medicine, Seoul (Korea, Republic of)

    1989-10-15

    A case of Fascioliasis of common bile duct is confirmed by visualization of adult fluke. Fascioliasis caused by Fasciola hepatica, is common parasitic disease in cattle and sheep. Human is an accidental host. ERCP demonstrated irregular linear conglomerated filling defects in common bile duct. Through surgical intervention, we found adult flukes of F. hepatica and adenomatous hyperplasia of common bile duct.

  12. Iatrogenic injury of an aberrant right posterior sectoral bile duct

    African Journals Online (AJOL)

    (Figs 1 and 2). A week later, an endoscopic retrograde cholangiopancreatography. (ERCP) examination was performed. This showed no filling of the right posterior sectoral ducts but normal opacification of the other ducts. (Figs 3a and b). These findings led to the diagnosis of an aberrant right posterior sectoral bile duct that ...

  13. Surgical management of Stenson's duct injury using epidural ...

    African Journals Online (AJOL)

    Surgical management of Stenson's duct injury using epidural catheter: A novel technique. ... It is in the form of ductal exposure, laceration, total severing, or crushing of the duct. These conditions are difficult to ... Many techniques have been proposed for diagnosis and management of parotid duct injuries. This article ...

  14. Termination pattern of the main and accessory pancreatic ducts ...

    African Journals Online (AJOL)

    The pancreas has the main and occasionally a patent accessory pancreatic ducts that carry secretions to the duodenum. Anatomical studies on these ducts are limited. The present study observed the anatomy of the two ducts in eighty six Tanzanians' autopsy subjects to find out if the pattern is similar to those reported from ...

  15. Experimental Research and Modeling of Particle Deposition in Ventilation Ducts

    Directory of Open Access Journals (Sweden)

    Hongming Fan

    2013-01-01

    Full Text Available The model to predict particle deposition velocity on rough walls in fully developed turbulent duct flows has been developed in previous studies. For particle deposition model boundary conditions, it is assumed that the concentration of the particle is zero on the surface and the resuspension velocity is constant. However, the resuspension velocity may not be constant with the increase in mass of the deposited dust. To analyze the behavior of resuspension in air flow, a set of experiments were designed and conducted. Results showed that there was a linear relationship between the mass of resuspension and deposited dust. Also, the particle deposition model was improved by adding a resuspension item to the equation, and the steady-state equation was developed into a time-varying equation. The analysis results are presented in this paper.

  16. MR findings in thyroglossal duct cysts

    International Nuclear Information System (INIS)

    Blandino, A.; Salvi, L.; Chirico, G.; Scribano, E.; Longo, M.; Pandolfo, I.

    1990-01-01

    Two patients with thyroglossal duct cysts have been studied with CT and MR. The typical CT feature of these cystic upper-neck lesions are depicted in literature, conversely MR findings are not well known. The homogeneous high intensity on T1-weighted images, higher than simple cyst or fluid, is the most typical feature of the thyroglossal cyst. (author). 12 refs.; 5 figs

  17. Whistler instability in a magnetospheric duct

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, I.; Tripathi, V.K. (Indian Inst. of Tech., New Delhi (India). Dept. of Physics); Jain, V.K. (Jawaharlal Nehru Univ., New Delhi (India). School of Environmental Sciences)

    1989-04-01

    A whistler wave propagating through a preformed magnetospheric duct is susceptible to growth/amplification by an electron beam. The interaction is non-local and could be of Cerenkov or slow-cyclotron type. First-order perturbation theory is employed to obtain the growth rate for flat and Gaussian beam densities. (author).

  18. Ducted wind turbines : A potential energy shaper

    NARCIS (Netherlands)

    Dighe, V.V.

    2016-01-01

    In order to harvest wind resources more efficiently and to the greatest extent possible, unconventional wind turbine designs have been proposed, but never gained any acceptance in the marketplace. A team of researchers from TU Delft plans to revisit the concept of ducted wind turbines, which have

  19. [Cervical thoracic duct cyst: An uncommon entity].

    Science.gov (United States)

    Carreira-Delgado, Manuel; Fernández-Rodríguez, Elvira; Martínez-Míguez, Marta; Álvarez-Martín, María Jesús; Nuño Vázquez-Garza, José Manuel

    2017-12-01

    Cervical thoracic duct cysts are a rare anomaly. To report a case of cervical thoracic duct cyst, and perform a literature review. A 78-year-old female, with a one-year history of a left-sided asymptomatic supraclavicular cystic mass. Computerized tomography revealed a cystic mass 42mm in diameter. We performed a fine needle aspiration puncture, obtaining a thick, milky, whitish liquid. The patient underwent surgery; finding a left-sided supraclavicular cystic mass, with some lymph vessels heading towards the jugulo subclavian venous junction. We performed a ligation of these lymph vessels and resection of the mass. The histopathologic study confirmed the diagnosis of thoracic duct cyst. Diagnosis of cervical thoracic duct cyst should be suspected with a cystic lesion in the left supraclavicular region, which when perforated exudes a very distinctive thick milky, whitish liquid with a high content of lymphocytes and triglycerides. Treatment should be complete removal with ligation of the lymphatic afferent vessels. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  20. Demand Response Performance of GE Hybrid Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Parker, Graham B.; Petersen, Joseph M.; Baechler, Michael C.

    2013-07-01

    This report describes a project to evaluate and document the DR performance of HPWH as compared to ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with GE second-generation “Brillion”-enabled GeoSpring hybrid water heaters in the PNNL Lab Homes, with one GE GeoSpring water heater operating in “Standard” electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in “Heat Pump” mode to provide the comparison to heat pump-only demand response. It is expected that “Hybrid” DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. This report presents the results of the evaluation, which documents the demand-response capability of the GE GeoSpring HPWH for peak load reduction and regulation services. The sections describe the experimental protocol and test apparatus used to collect data, present the baselining procedure, discuss the results of the simulated DR events for the HPWH and ERWH, and synthesize key conclusions based on the collected data.

  1. 40 CFR 63.988 - Incinerators, boilers, and process heaters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Incinerators, boilers, and process... Routing to a Fuel Gas System or a Process § 63.988 Incinerators, boilers, and process heaters. (a) Equipment and operating requirements. (1) Owners or operators using incinerators, boilers, or process...

  2. Severe burns due to biofuel heater injury: A case series.

    Science.gov (United States)

    Heald, Alicia; Muller, Michael

    2016-03-01

    Biofuel heaters are a new form of flame heating for indoor and outdoor use. Fuelled by methylated spirits, they are simple structures with few safety features, and can be associated with severe burn. We report five cases of severe burns in adults that occurred when refilling these heaters. We undertook a retrospective audit of all adults presenting to the Royal Brisbane and Women's Hospital (RBWH) with a biofuel heater-related burn between 20 and 30th June 2014. Five patients required admission for management of their burns. Three were admitted to ICU for greater than 3 weeks, and remained inpatients for up to 78 days. Two did not require ICU and were managed in the burns unit. Average total body surface area (TBSA) burned was 24.7%, and patients went to theatre up to seven times for debridement and skin grafting. Average length of stay was 41.8 days. Biofuel heaters are easily accessible yet there is no Australian Standard to ensure they are safe or perform in the way they were intended. As such, people using them are at undue risk of severe burn, even when following the operating instructions. These products should be removed from the market to prevent further harm and potential mortality. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  3. Laser/TIG Hybrid Welding of Pot for Induction Heater

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove; Sondrup, Lars de Caldas

    2004-01-01

    In this paper, systematic work is presented that shows the steps for realizing a hybrid welded tailored blank that is formed to a pot for induction heating. The bottom is made of ferritic stainless steel and the sides of austenitic stainless steel. Only the bottom will then interact directly with...... with the induction heater....

  4. An Automatic Safety Control for Immersion Water Heater | Enokela ...

    African Journals Online (AJOL)

    The heating of liquids, especially water, is carried out in the homes and industries for various reasons. The domestic water heater has become a near- ubiquitous appliance in the Nigerian homes. An important source of concern with this appliance is the frequent possibility of outbreak of fire due to negligence on the part of ...

  5. Fast thermal nanoimprint lithography by a stamp with integrated heater

    DEFF Research Database (Denmark)

    Tormen, Massimo; Malureanu, Radu; Pedersen, Rasmus Haugstrup

    2008-01-01

    We propose fast nanoimprinting lithography (NIL) process based on the use of stamps with integrated heater. The latter consists of heavily ion implantation n-type doped silicon layer buried below the microstructured surface of the stamp. The stamp is heated by Joule effect, by 50 μs 25 Hz...

  6. 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

  7. Solar water heaters in China: A new day dawning

    NARCIS (Netherlands)

    Han, Jingyi; Mol, A.P.J.; Lu, Y.

    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

  8. 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.

  9. South Africa. Fertile ground for solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Oirere, Shem

    2012-07-01

    The national solar water heating plan, launched by South Africa's state power utility Eskom, seems to be making good progress with the power generator saying at least 215,000 solar water heater (SWH) systems had been installed by February this year. (orig.)

  10. Silicon microbench heater elements for packaging opto-electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Combs, R.; Keiser, P.; Kleint, K.; Pocha, M.; Patterson, F.; Strand, O.T.

    1995-09-01

    Examples are presented of the application of Lawrence Livermore National Laboratory`s expertise in photonics packaging. Several examples of packaged devices will be described. Particular attention is given to silicon microbenches incorporating heaters and their use in semiconductor optical amplifier fiber pigtailing and packaging.

  11. solar dryer with biomass backup heater for drying fruits

    African Journals Online (AJOL)

    Most solar dryers rely on only solar energy as the heat source. This condition limits its use in off -sunny periods such as cloudy, rainy seasons and after sunset. The objectives of this study were to: develop a solar dryer with biomass backup heater for drying fruits; analyze its performance; and carry out comparative analysis ...

  12. CHARACTERIZATION OF POPULATION AND USAGE OF UNVENTED KEROSENE SPACE HEATERS

    Science.gov (United States)

    The report gives results of a study of the market penetration of unvented kerosene space heaters (UKSHs) in the residential sector, The study was aimed at gathering baseline information to help assess the magnitude and potential severity of a problem involving emissions from unve...

  13. 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.

  14. Nuclear plant power up-rate study: feedwater heater evaluations

    International Nuclear Information System (INIS)

    Svensson, Eric; Catapano, Michael; Coakley, Michael; Thomas, Dan

    2014-01-01

    Given today's nuclear industry business climate, it has become common for Utility companies to consider increasing unit capacities through turbine replacement and power up-rates. An integral part of the studies conducted by many towards this end, involve the generation of a set of turbine cycle heat balances with predicted performance parameters for the up-rated condition. Once these tentative operating values are established, it becomes necessary to evaluate the suitability of the existing components within each system to ensure they are capable of continued safe and reliable operation. The ultimate cost for the up-rate, including the cost for any major required modifications or significant replacements is weighed against increased revenue generated from the up-rate over time. Exelon's Peach Bottom Atomic Power Station (PBAPS) is currently planning for an Extended Power up-rate (EPU) for both units. To ensure the existing Feedwater Heaters (FWH) could maintain the operating and transient response margins at the EPU condition, an engineering study was conducted. Powerfect Inc. in conjunction with SPX Heat Transfer LLC were contracted to provide engineering services to analyze the design, thermal performance, reliability and operating conditions at projected EPU conditions. Specifically, to address the following with regard to the station's Feedwater Heaters (FWHs): 1. Evaluate Drain Cooler (DC) Velocities - including zone inlet velocity, cross and window velocities and outlet velocities. 2. Evaluate Drain Cooler Zone Pressure Drop for effect on drain cooler margins to flashing. 3. Evaluate differential pressure allowable across the pass partition plate. 4. Evaluate Drain Cooler Tube Vibration Potential. 5. Perform detailed steam dome velocity calculations. The goal of the study was to identify the most susceptible areas within the heaters for problems and potential failures when operating at the higher duty of the EPU condition for the remaining life

  15. CT findings of thyroglossal duct cyst

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Oh; Kim, Hong Soo; So, Hyun Soon; Nam, Mee Young; Choi, Jae Ho; Rhee, Hak Song [Presbyterian Medical Center, Jeonju (Korea, Republic of)

    1995-05-15

    The purpose of this study was to evaluate the CT findings of thyroglossal duct cysts. Sixteen patients with pathologically proved thyroglossal duct cysts were included in the study. CT scans were assessed retrospectively for shape, size, location, density of the central portions, septations, rim enhancement, changes in the adjacent fascial planes and investment within the strap muscles in the infrahyoid cysts. Thirteen cases of thyroglossal duct cysts were seen as round or oval cystic masses, two cases of them were seen as irregular-shaped lobulated cystic masses, and one case was seen as ovoid soft tissue mass. The cysts were from 1.4 to 5.7 cm in diameter (mean, 2.6 cm). The cyst was infrahyoid in 15 cases and suprahyoid in one case. The cyst was located in midline in eight cases, off midline in four cases, and both midline and off midline in four cases. The density of the central portions ranged from 15 to 82HU (mean, 32HU). Septations were noted in four cases. Rim enhancement was seen in 14 cases (93%), and heterogeneously enhancing soft tissue mass was seen in one case. In four cases, abnormal fascial planes were observed. All but one of the infrahyoid cysts (14/15) were embedded within the strap muscles, and one case of them was located anteriorly to strap muscles. CT permits one to make the diagnosis a thyroglossal duct cyst with a high degree of accuracy, as it can differentiate thyroglossal duct cysts from the other anterior neck masses by their typical location, characteristic morphology, and investment within the strap muscles.

  16. Tolerance of bile duct to intraoperative irradiation

    International Nuclear Information System (INIS)

    Sindelar, W.F.; Tepper, J.; Travis, E.L.

    1982-01-01

    In order to determine the effects of intraoperative radiation therapy of the bile duct and surrounding tissues, seven adult dogs were subjected to laparotomy and intraoperative irradiation with 11 MeV electrons. Two animals were treated at each dose level of 2000, 3000, and 4500 rads. A single dog which received a laparotomy and sham irradiation served as a control. The irradiation field consisted of a 5 cm diameter circle encompassing the extrahepatic bile duct, portal vein, hepatic artery, and lateral duodenal wall. The animals were followed clinically for mor than 18 months after treatment, and autopsies were performed on dogs that died to assess radiation-induced complications or tissue damage. All dogs developed fibrosis and mural thickening of the common duct, which appeared by 6 weeks following irradiation and which was dose-related, being mild at low doses and more severe at high doses. Hepatic changes were seen as early as 6 weeks after irradiation, consisting of periportal inflammation and fibrosis. The hepatic changes appeared earliest at the highest doses. Frank biliary cirrhosis eventually developed at all dose levels. Duodenal fibrosis appeared in the irradiation portal, being most severe at the highest doses and in some animals resulting in duodenal obstruction. No changes were observed in irradiated portions of portal vein and hepatic artery at any dose level. It was concluded that intraoperative radiation therapy delivered to the region of the common duct leads to ductal fibrosis, partial biliary obstruction with secondary hepatic changes, and duodenal fibrosis if bowel wall is included in the field. Clinical use of intraoperative radiation therapy to the bile duct in humans may require routine use of biliary and duodenal bypass to prevent obstructive complications

  17. CT findings of thyroglossal duct cyst

    International Nuclear Information System (INIS)

    Kim, Dong Oh; Kim, Hong Soo; So, Hyun Soon; Nam, Mee Young; Choi, Jae Ho; Rhee, Hak Song

    1995-01-01

    The purpose of this study was to evaluate the CT findings of thyroglossal duct cysts. Sixteen patients with pathologically proved thyroglossal duct cysts were included in the study. CT scans were assessed retrospectively for shape, size, location, density of the central portions, septations, rim enhancement, changes in the adjacent fascial planes and investment within the strap muscles in the infrahyoid cysts. Thirteen cases of thyroglossal duct cysts were seen as round or oval cystic masses, two cases of them were seen as irregular-shaped lobulated cystic masses, and one case was seen as ovoid soft tissue mass. The cysts were from 1.4 to 5.7 cm in diameter (mean, 2.6 cm). The cyst was infrahyoid in 15 cases and suprahyoid in one case. The cyst was located in midline in eight cases, off midline in four cases, and both midline and off midline in four cases. The density of the central portions ranged from 15 to 82HU (mean, 32HU). Septations were noted in four cases. Rim enhancement was seen in 14 cases (93%), and heterogeneously enhancing soft tissue mass was seen in one case. In four cases, abnormal fascial planes were observed. All but one of the infrahyoid cysts (14/15) were embedded within the strap muscles, and one case of them was located anteriorly to strap muscles. CT permits one to make the diagnosis a thyroglossal duct cyst with a high degree of accuracy, as it can differentiate thyroglossal duct cysts from the other anterior neck masses by their typical location, characteristic morphology, and investment within the strap muscles

  18. Mockup Small-Diameter Air Distribution System

    Energy Technology Data Exchange (ETDEWEB)

    A. Poerschke and A. Rudd

    2016-05-01

    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 hander 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.

  19. Evaluation of the Demand Response Performance of Electric Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widder, Sarah H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Parker, Steven A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pratt, Richard M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chassin, Forrest S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    The purpose of this project is to verify or refute many of the concerns raised by utilities regarding the ability of large tank HPWHs to perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. This project was divided into three phases. Phase 1 consisted of week-long laboratory experiments designed to demonstrate technical feasibility of individual large-tank HPWHs in providing DR services compared to large-tank ERWHs. In Phase 2, the individual behaviors of the water heaters were then extrapolated to a population by first calibrating readily available water heater models developed in GridLAB-D simulation software to experimental results obtained in Phase 1. These models were used to simulate a population of water heaters and generate annual load profiles to assess the impacts on system-level power and residential load curves. Such population modeling allows for the inherent and permanent load reduction accomplished by the more efficient HPWHs to be considered, in addition to the temporal DR services the water heater can provide by switching ON or OFF as needed by utilities. The economic and emissions impacts of using large-tank water heaters in DR programs are then analyzed from the utility and consumer perspective, based on National Impacts Analysis in Phase 3. Phase 1 is discussed in this report. Details on Phases 2 and 3 can be found in the companion report (Cooke et al. 2014).

  20. CFD validation by measurement of specialized ventilation equipments on duct tract

    Directory of Open Access Journals (Sweden)

    Sehnalek Stanislav

    2017-01-01

    Full Text Available This article describes measurement of HVAC distribution box on air duct track in Laboratory of Environmental Engineering (LEE. Firstly, the paper describes the LEE and then measurement apparatus with description of calculation methods. Then follows specification of sample with introduction to newly developed equipment for positioning of the anemometer. The evaluation of results of measurements with CFD comparison follows. The article is concluded with discussion over measured data with an outline for further research.