Sample records for bayonet heat exchanger

  1. Heat exchanger for reactor core and the like

    DOEpatents

    Kaufman, Jay S.; Kissinger, John A.

    1986-01-01

    A compact bayonet tube type heat exchanger which finds particular application as an auxiliary heat exchanger for transfer of heat from a reactor gas coolant to a secondary fluid medium. The heat exchanger is supported within a vertical cavity in a reactor vessel intersected by a reactor coolant passage at its upper end and having a reactor coolant return duct spaced below the inlet passage. The heat exchanger includes a plurality of relatively short length bayonet type heat exchange tube assemblies adapted to pass a secondary fluid medium therethrough and supported by primary and secondary tube sheets which are releasibly supported in a manner to facilitate removal and inspection of the bayonet tube assemblies from an access area below the heat exchanger. Inner and outer shrouds extend circumferentially of the tube assemblies and cause the reactor coolant to flow downwardly internally of the shrouds over the tube bundle and exit through the lower end of the inner shroud for passage to the return duct in the reactor vessel.

  2. Qualification of Sub-Atmospheric Pressure Sensors for the Cryomagnet Bayonet Heat Exchangers of the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Bager, T.; Casas-Cubillos, J.; Jeanmonod, N.

    2006-04-01

    The superconducting magnets of the Large Hadron Collider (LHC) will be cooled at 1.9 K by distributed cooling loops working with saturated two-phase superfluid helium flowing in 107 m long bayonet heat exchangers located in each magnet cold-mass cell. The temperature of the magnets could be difficult to control because of the large dynamic heat load variations. Therefore, it is foreseen to measure the heat exchangers pressure to feed the regulation loops with the corresponding saturation temperature. The required uncertainty of the sub-atmospheric saturation pressure measurement shall be of the same order of the one associated to the magnet thermometers, in pressure it translates as ±5 Pa at 1.6 kPa. The transducers shall be radiation hard as they will endure, in the worst case, doses up to 10 kGy and 1015 neutronsṡcm-2 over 10 years. The sensors under evaluation were installed underground in the dump section of the SPS accelerator with a radiation environment close to the one expected for the LHC. The monitoring equipment was installed in a remote radiation protected area. This paper presents the results of the radiation qualification campaign with emphasis on the reliability and accuracy of the pressure sensors under the test conditions.

  3. Integrated boiler, superheater, and decomposer for sulfuric acid decomposition

    DOEpatents

    Moore, Robert [Edgewood, NM; Pickard, Paul S [Albuquerque, NM; Parma, Jr., Edward J.; Vernon, Milton E [Albuquerque, NM; Gelbard, Fred [Albuquerque, NM; Lenard, Roger X [Edgewood, NM

    2010-01-12

    A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.

  4. Pre-test analysis of protected loss of primary pump transients in CIRCE-HERO facility

    NASA Astrophysics Data System (ADS)

    Narcisi, V.; Giannetti, F.; Del Nevo, A.; Tarantino, M.; Caruso, G.

    2017-11-01

    In the frame of LEADER project (Lead-cooled European Advanced Demonstration Reactor), a new configuration of the steam generator for ALFRED (Advanced Lead Fast Reactor European Demonstrator) was proposed. The new concept is a super-heated steam generator, double wall bayonet tube type with leakage monitoring [1]. In order to support the new steam generator concept, in the framework of Horizon 2020 SESAME project (thermal hydraulics Simulations and Experiments for the Safety Assessment of MEtal cooled reactors), the ENEA CIRCE pool facility will be refurbished to host the HERO (Heavy liquid mEtal pRessurized water cOoled tubes) test section to investigate a bundle of seven full scale bayonet tubes in ALFRED-like thermal hydraulics conditions. The aim of this work is to verify thermo-fluid dynamic performance of HERO during the transition from nominal to natural circulation condition. The simulations have been performed with RELAP5-3D© by using the validated geometrical model of the previous CIRCE-ICE test section [2], in which the preceding heat exchanger has been replaced by the new bayonet bundle model. Several calculations have been carried out to identify thermal hydraulics performance in different steady state conditions. The previous calculations represent the starting points of transient tests aimed at investigating the operation in natural circulation. The transient tests consist of the protected loss of primary pump, obtained by reducing feed-water mass flow to simulate the activation of DHR (Decay Heat Removal) system, and of the loss of DHR function in hot conditions, where feed-water mass flow rate is absent. According to simulations, in nominal conditions, HERO bayonet bundle offers excellent thermal hydraulic behavior and, moreover, it allows the operation in natural circulation.

  5. Effect of the connection gap on the heat-load characteristics of a liquid nitrogen bayonet coupling

    NASA Astrophysics Data System (ADS)

    Tsai, H. H.; Liu, C. P.; Hsiao, F. Z.; Huang, T. Y.; Li, H. C.; Chiou, W. S.; Chang, S. H.; Lin, T. F.

    2012-12-01

    A transfer system for liquid nitrogen (LN2) installed at National Synchrotron Radiation Research Center (NSRRC) to provide LN2 required for the superconducting equipment and experimental stations has a LN2 transfer line of length 160 m and pipeline of inner diameter 25 mm, a phase separator (250 L) and an automatic filling station. The end uses include two cryogenic systems, one Superconducting Radio Frequency (SRF) cavity, five superconducting magnets, monochromators for the beam line and filling of mobile Dewars. The transfer line is segmented and connected with bayonet couplings. The aim of this work was to investigate, by numerical simulation, the effects on the heat load of the gap thickness of the bayonet assembly and the thickness of vacuum insulation. A numerical correlation was created that has become a basis to minimize the head load for future design of bayonet couplings.

  6. Adaption of the LHC cold mass cooling system to the requirements of the Future Circular Collider (FCC)

    NASA Astrophysics Data System (ADS)

    Kotnig, C.; Tavian, L.; Brenn, G.

    2017-12-01

    The cooling of the superconducting magnet cold masses with superfluid helium (He II) is a well-established concept successfully in operation for years in the LHC. Consequently, its application for the cooling of FCC magnets is an obvious option. The 12-kW heat loads distributed over 10-km long sectors not only require an adaption of the magnet bayonet heat exchangers but also present new challenges to the cryogenic plants, the distribution system and the control strategy. This paper recalls the basic LHC cooling concept with superfluid helium and defines the main parameters for the adaption to the FCC requirements. Pressure drop and hydrostatic head are developed in the distribution and pumping systems; their impact on the magnet temperature profile and the corresponding cooling efficiency is presented and compared for different distribution and pumping schemes.

  7. Apparatus and methods for regeneration of precipitating solvent

    DOEpatents

    Liu, Guohai; Vimalchand, Pannalal; Peng, Wan Wang; Bonsu, Alexander

    2015-08-25

    A regenerator that can handle rich loaded chemical solvent containing precipitated absorption reaction products is disclosed. The invention is particularly suitable for separating CO.sub.2 from large gas streams that are typical of power plant processes. The internally circulating liquid stream in the regenerator (ICLS regenerator) rapidly heats-up the in-coming rich solvent stream in a downcomer standpipe as well as decreases the overall concentration of CO.sub.2 in the mixed stream. Both these actions lead to dissolution of precipitates. Any remaining precipitate further dissolves as heat is transferred to the mixed solution with an inverted bayonet tube heat exchanger in the riser portion of the regenerator. The evolving CO.sub.2 bubbles in the riser portion of the regenerator lead to substantial gas hold-up and the large density difference between the solutions in the downcomer standpipe and riser portions promotes internal circulation of the liquid stream in the regenerator. As minor amounts of solvent components present in the exit gas stream are condensed and returned back to the regenerator, pure CO.sub.2 gas stream exits the disclosed regenerator and condenser system.

  8. Hybrid sulfur cycle operation for high-temperature gas-cooled reactors

    DOEpatents

    Gorensek, Maximilian B

    2015-02-17

    A hybrid sulfur (HyS) cycle process for the production of hydrogen is provided. The process uses a proton exchange membrane (PEM) SO.sub.2-depolarized electrolyzer (SDE) for the low-temperature, electrochemical reaction step and a bayonet reactor for the high-temperature decomposition step The process can be operated at lower temperature and pressure ranges while still providing an overall energy efficient cycle process.

  9. Space and Missile Systems Center Standard: Technical Requirements for Electronic Parts, Materials, and Processes used in Space Vehicles

    DTIC Science & Technology

    2013-04-12

    DTL-38999 Connector, Electrical, Circular, Miniature, High Density, Quick Disconnect (Bayonet, Threaded , and Breach Coupling), Environment Resistant ...186 Table 1160-1. Resistance Tolerance and Required Derating...For MIL-DTL-5015 Connector, Electrical, Circular Threaded , AN Type, General Specification for MIL-H-6088G(1) Heat Treatment of Aluminum Alloys

  10. Design of an Experimental Facility for Passive Heat Removal in Advanced Nuclear Reactors

    NASA Astrophysics Data System (ADS)

    Bersano, Andrea

    With reference to innovative heat exchangers to be used in passive safety system of Gen- eration IV nuclear reactors and Small Modular Reactors it is necessary to study the natural circulation and the efficiency of heat removal systems. Especially in safety systems, as the decay heat removal system of many reactors, it is increasing the use of passive components in order to improve their availability and reliability during possible accidental scenarios, reducing the need of human intervention. Many of these systems are based on natural circulation, so they require an intense analysis due to the possible instability of the related phenomena. The aim of this thesis work is to build a scaled facility which can reproduce, in a simplified way, the decay heat removal system (DHR2) of the lead-cooled fast reactor ALFRED and, in particular, the bayonet heat exchanger, which transfers heat from lead to water. Given the thermal power to be removed, the natural circulation flow rate and the pressure drops will be studied both experimentally and numerically using the code RELAP5 3D. The first phase of preliminary analysis and project includes: the calculations to design the heat source and heat sink, the choice of materials and components and CAD drawings of the facility. After that, the numerical study is performed using the thermal-hydraulic code RELAP5 3D in order to simulate the behavior of the system. The purpose is to run pretest simulations of the facility to optimize the dimensioning setting the operative parameters (temperature, pressure, etc.) and to chose the most adequate measurement devices. The model of the system is continually developed to better simulate the system studied. High attention is dedicated to the control logic of the system to obtain acceptable results. The initial experimental tests phase consists in cold zero power tests of the facility in order to characterize and to calibrate the pressure drops. In future works the experimental results will be compared to the values predicted by the system code and differences will be discussed with the ultimate goal to qualify RELAP5-3D for the analysis of decay heat removal systems in natural circulation. The numerical data will be also used to understand the key parameters related to the heat transfer in natural circulation and to optimize the operation of the system.

  11. High temperature penetrator assembly with bayonet plug and ramp-activated lock

    NASA Technical Reports Server (NTRS)

    Wood, K. E. (Inventor)

    1982-01-01

    A penetration apparatus, for very high temperature applications in which a base plug is inserted into an opening through a bulkhead is described. The base plug has a head shape and is seated against the highest temperature surface of the bulkhead, which may be the skin of the nose cone or other part of a space vehicle intended for nondestructive atmospheric reentry. From the second side of the bulkhead at which the less severe environment is extant, a bayonet plug is inserted into the base plug and engages an internal shoulder at about 90 deg rotation. The bayonet plug has an integral flanged portion and a pair of ramping washers which are located between the flange and the second bulkhead surface with a spacing washer as necessary.

  12. Reusable Hot-Wire Cable Cutter

    NASA Technical Reports Server (NTRS)

    Pauken, Michael T.; Steinkraus, Joel M.

    2010-01-01

    During the early development stage of balloon deployment systems for missions, nichrome wire cable cutters were often used in place of pyro-actuated cutters. Typically, a nichrome wire is wrapped around a bundle of polymer cables with a low melting point and connected to a relay-actuated electric circuit. The heat from the nichrome reduces the strength of the cable bundle, which quickly breaks under a mechanical load and can thus be used as a release mechanism for a deployment system. However, the use of hand-made heated nichrome wire for cutters is not very reliable. Often, the wrapped nichrome wire does not cut through the cable because it either pulls away from its power source or does not stay in contact with the cable being cut. Because nichrome is not readily soldered to copper wire, unreliable mechanical crimps are often made to connect the nichrome to an electric circuit. A self-contained device that is reusable and reliable was developed to sever cables for device release or deployment. The nichrome wire in this new device is housed within an enclosure to prevent it from being damaged by handling. The electric power leads are internally connected within the unit to the nichrome wire using a screw terminal connection. A bayonet plug, a quick and secure method of connecting the cutter to the power source, is used to connect the cutter to the power leads similar to those used in pyro-cutter devices. A small ceramic tube [0.25-in. wide 0.5-in. long (.6.4-mm wide 13-mm long)] houses a spiraled nichrome wire that is heated when a cable release action is required. The wire is formed into a spiral coil by wrapping it around a mandrel. It is then laid inside the ceramic tube so that it fits closely to the inner surface of the tube. The ceramic tube provides some thermal and electrical insulation so that most of the heat generated by the wire is directed toward the cable bundle in the center of the spiral. The ceramic tube is cemented into an aluminum block, which holds it in position. The leads of the nichrome wire are attached to screw terminals that connect them to power leads. A bayonet plug mounted at the bottom of the rectangular block connects the power leads to a relay circuit. A thin aluminum shell encloses the entire structure, leaving access points to attach to the bayonet plug and to feed a cable into the cylinder. The access holes for the deployment cable are a smaller diameter than the nichrome coil to prevent the cable from coming in direct contact with the nichrome when loaded. It uses the same general method of severing a cable with a heated wire as was used previously, but implements it in such a way that it is more reliable and less prone to failure. It creates a mechanism to create repeatability that was nonexistent in the previous method.

  13. THREADED ADAPTOR FOR LUGGED PIPE ENDS

    DOEpatents

    Robb, J.E.

    1962-06-01

    An adaptor is designed for enabling a threaded part to be connected to a member at a region having lugs normally receiving bayonet slots of another part for attachment of the latter. It has been found desirable to replace a closure cap connected in a bayonet joint to the end of a coolant tube containing nuclear- reactor fuel elements, with a threaded valve. An adaptor is used which has J- slots receiving lugs on the end of the reactor tube, a thread for connection with the valve, and gear-tooth section enabling a gear-type of tool to rotate the adaptor to seal the valve to the end of the reactor tube. (AEC)

  14. Development of the hybrid sulfur cycle for use with concentrated solar heat. I. Conceptual design

    DOE PAGES

    Gorensek, Maximilian B.; Corgnale, Claudio; Summers, William A.

    2017-07-27

    We propose a detailed conceptual design of a solar hybrid sulfur (HyS) cycle. Numerous design tradeoffs, including process operating conditions and strategies, methods of integration with solar energy sources, and solar design options were considered. A baseline design was selected, and process flowsheets were developed. Pinch analyses were performed to establish the limiting energy efficiency. Detailed material and energy balances were completed, and a full stream table prepared. Design assumptions include use of: location in the southwest US desert, falling particle concentrated solar receiver, indirect heat transfer via pressurized helium, continuous operation with thermal energy storage, liquid-fed electrolyzer with PBImore » membrane, and bayonet-type acid decomposer. Thermochemical cycle efficiency for the HyS process was estimated to be 35.0%, LHV basis. The solar-to-hydrogen (STH) energy conversion ratio was 16.9%. This thus exceeds the Year 2015 DOE STCH target of STH >10%, and shows promise for meeting the Year 2020 target of 20%.« less

  15. Development of the hybrid sulfur cycle for use with concentrated solar heat. I. Conceptual design

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gorensek, Maximilian B.; Corgnale, Claudio; Summers, William A.

    We propose a detailed conceptual design of a solar hybrid sulfur (HyS) cycle. Numerous design tradeoffs, including process operating conditions and strategies, methods of integration with solar energy sources, and solar design options were considered. A baseline design was selected, and process flowsheets were developed. Pinch analyses were performed to establish the limiting energy efficiency. Detailed material and energy balances were completed, and a full stream table prepared. Design assumptions include use of: location in the southwest US desert, falling particle concentrated solar receiver, indirect heat transfer via pressurized helium, continuous operation with thermal energy storage, liquid-fed electrolyzer with PBImore » membrane, and bayonet-type acid decomposer. Thermochemical cycle efficiency for the HyS process was estimated to be 35.0%, LHV basis. The solar-to-hydrogen (STH) energy conversion ratio was 16.9%. This thus exceeds the Year 2015 DOE STCH target of STH >10%, and shows promise for meeting the Year 2020 target of 20%.« less

  16. Design of a 0-50 mbar pressure measurement channel compatible with the LHC tunnel radiation environment

    NASA Astrophysics Data System (ADS)

    Casas, Juan; Jelen, Dorota; Trikoupis, Nikolaos

    2017-02-01

    The monitoring of cryogenic facilities often require the measurement of pressure in the sub 5’000 Pa range that are used for flow metering applications, for saturated superfluid helium, etc. The pressure measurement is based on the minute displacement of a sensing diaphragm often through contactless techniques by using capacitive or inductive methods. The LHC radiation environment forbid the use of standard commercial sensors because of the embedded electronics that are affected both by radiation induced drift and transient Single Event Effects (SEE). Passive pressure sensors from two manufacturers were investigated and a CERN designed radiation-tolerant electronics has been developed for measuring variable-reluctance sensors. During the last maintenance stop of the LHC accelerator, four absolute pressure sensors were installed in some of the low pressure bayonet heat exchangers and four differential pressure sensors on the venturi flowmeters that monitor the cooling flow of the 20.5 kA current leads of the ATLAS end-cap superconducting toroids. The pressure sensors operating range is about 1000 to 5000 Pa and the targeted uncertainty is +/- 50 Pa which would permit to measure the equivalent saturation temperature at 1.8 K within better than 0.01 K. This paper describes the radiation hard measuring head that is based on an inductive bridge, its associated radiation-tolerant electronics that is installed under the LHC superconducting magnets or the ATLAS detector cavern; and the first operational experience.

  17. Low energy sign illumination system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Minogue, R.W.

    A low energy sign contruction is illustrated for illumination of signs of the type having translucent illuminated faces. An opaque sign border is bridged by a reflector extending generally parallel to the illuminated face and having a truncated sawtooth profile. For single sided signs, one set of sawtooth points is truncated; for dual sided signs, both set of sawtooth points are truncated. Bayonet mounted lighting sockets are mounted at apertures in the respective truncations and utilize the metallic reflective surface as one side of a low voltage (10.5-volt) ac circuit. The reflector forms a cooled heat sink mounting the bulbsmore » as well as a supporting matrix. The lamps, as mounted to this supporting matrix, are typically spaced at distances which do not exceed twice the distance of the lamp filament to the translucent face. By the expedient of using 14-V lamps, prolonged lamp life with low energy illumination results.« less

  18. Segmented heat exchanger

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron

    2010-12-14

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

  19. Dual source heat pump

    DOEpatents

    Ecker, Amir L.; Pietsch, Joseph A.

    1982-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  20. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1979-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchangers and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  1. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1982-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  2. 40 CFR 63.654 - Heat exchange systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) through (g) of this section if all heat exchangers within the heat exchange system either: (1) Operate... exposure to air for each heat exchange system. (ii) Selected heat exchanger exit line(s) so that each heat exchanger or group of heat exchangers within a heat exchange system is covered by the selected monitoring...

  3. 40 CFR 63.654 - Heat exchange systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) through (g) of this section if all heat exchangers within the heat exchange system either: (1) Operate... exposure to air for each heat exchange system. (ii) Selected heat exchanger exit line(s) so that each heat exchanger or group of heat exchangers within a heat exchange system is covered by the selected monitoring...

  4. 40 CFR 63.654 - Heat exchange systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... section. (1) All heat exchangers that are in organic HAP service within the heat exchange system that...., the heat exchange system does not contain any heat exchangers that are in organic HAP service as... exchange system in organic HAP service or from each heat exchanger exit line for each heat exchanger or...

  5. 40 CFR 63.654 - Heat exchange systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... section. (1) All heat exchangers that are in organic HAP service within the heat exchange system that...., the heat exchange system does not contain any heat exchangers that are in organic HAP service as... exchange system in organic HAP service or from each heat exchanger exit line for each heat exchanger or...

  6. Heat pump with freeze-up prevention

    DOEpatents

    Ecker, Amir L.

    1981-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid prevents freeze up of the second heat exchanger by keeping the temperature above the dew point; and, optionally, provides heat for efficient operation.

  7. Analysis of the heat transfer in double and triple concentric tube heat exchangers

    NASA Astrophysics Data System (ADS)

    Rădulescu, S.; Negoiţă, L. I.; Onuţu, I.

    2016-08-01

    The tubular heat exchangers (shell and tube heat exchangers and concentric tube heat exchangers) represent an important category of equipment in the petroleum refineries and are used for heating, pre-heating, cooling, condensation and evaporation purposes. The paper presents results of analysis of the heat transfer to cool a petroleum product in two types of concentric tube heat exchangers: double and triple concentric tube heat exchangers. The cooling agent is water. The triple concentric tube heat exchanger is a modified constructive version of double concentric tube heat exchanger by adding an intermediate tube. This intermediate tube improves the heat transfer by increasing the heat area per unit length. The analysis of the heat transfer is made using experimental data obtained during the tests in a double and triple concentric tube heat exchanger. The flow rates of fluids, inlet and outlet temperatures of water and petroleum product are used in determining the performance of both heat exchangers. Principally, for both apparatus are calculated the overall heat transfer coefficients and the heat exchange surfaces. The presented results shows that triple concentric tube heat exchangers provide better heat transfer efficiencies compared to the double concentric tube heat exchangers.

  8. Corrosive resistant heat exchanger

    DOEpatents

    Richlen, Scott L.

    1989-01-01

    A corrosive and errosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is conveyed through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium.

  9. The Department of Defense Press Pool: Did in Work in Panama?

    DTIC Science & Technology

    1990-01-01

    who would physically attack a paper and its printer that did not reflect their opinion (Tebbel, 5). Politicians rarely brought the papers to task...Rico single-handedly and James Creelman , a reporter for Hearst, leading a bayonet charge outside Santiago. Military and press relations were good. The

  10. Multiple source heat pump

    DOEpatents

    Ecker, Amir L.

    1983-01-01

    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  11. A corrosive resistant heat exchanger

    DOEpatents

    Richlen, S.L.

    1987-08-10

    A corrosive and erosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium. 3 figs., 3 tabs.

  12. Heat exchanger life extension via in-situ reconditioning

    DOEpatents

    Holcomb, David E.; Muralidharan, Govindarajan

    2016-06-28

    A method of in-situ reconditioning a heat exchanger includes the steps of: providing an in-service heat exchanger comprising a precipitate-strengthened alloy wherein at least one mechanical property of the heat exchanger is degraded by coarsening of the precipitate, the in-service heat exchanger containing a molten salt working heat exchange fluid; deactivating the heat exchanger from service in-situ; in a solution-annealing step, in-situ heating the heat exchanger and molten salt working heat exchange fluid contained therein to a temperature and for a time period sufficient to dissolve the coarsened precipitate; in a quenching step, flowing the molten salt working heat-exchange fluid through the heat exchanger in-situ to cool the alloy and retain a supersaturated solid solution while preventing formation of large precipitates; and in an aging step, further varying the temperature of the flowing molten salt working heat-exchange fluid to re-precipitate the dissolved precipitate.

  13. Development, Fabrication, and Testing of a Liquid/Liquid Microchannel Heat Exchanger for Constellation Spacecrafts

    NASA Technical Reports Server (NTRS)

    Hawkins-Reynolds, Ebony; Le,Hung; Stephans, Ryan A.

    2009-01-01

    Minimizing mass and volume is critically important for space hardware. Microchannel technology can be used to decrease both of these parameters for heat exchangers. Working in concert with NASA, Pacific Northwest National Laboratories (PNNL) has developed a microchannel liquid/liquid heat exchanger that has resulted in significant mass and volume savings. The microchannel heat exchanger delivers these improvements without sacrificing thermal and pressure drop performance. A conventional heat exchanger has been tested and the performance of it recorded to compare it to the microchannel heat exchanger that PNNL has fabricated. The microchannel heat exchanger was designed to meet all of the requirements of the baseline heat exchanger, while reducing the heat exchanger mass and volume. The baseline heat exchanger was designed to have an transfer approximately 3.1 kW for a specific set of inlet conditions. The baseline heat exchanger mass was 2.7 kg while the microchannel mass was only 2.0 kg. More impressive, however, was the volumetric savings associated with the microchannel heat exchanger. The microchannel heat exchanger was an order of magnitude smaller than the baseline heat exchanger (2180cm3 vs. 311 cm3). This paper will describe the test apparatus designed to complete performance tests for both heat exchangers. Also described in this paper will be the performance specifications for the microchannel heat exchanger and how they compare to the baseline heat exchanger.

  14. Heat pump employing optimal refrigerant compressor for low pressure ratio applications

    DOEpatents

    Ecker, Amir L.

    1982-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler for circulating the fluid in heat exchange relationship with a refrigerant fluid; two refrigerant heat exchangers; one for effecting the heat exchange with the fluid and a second refrigerant-heat exchange fluid heat exchanger for effecting a low pressure ratio of compression of the refrigerant; a rotary compressor for compressing the refrigerant with low power consumption at the low pressure ratio; at least one throttling valve connecting at the inlet side of heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit serially connecting the above elements; refrigerant in the circuit; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant.

  15. 40 CFR 63.1409 - Heat exchange system provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and exits each heat exchanger or any combination of heat exchangers. (i) For samples taken at the... entrance and exit of each heat exchanger or any combination of heat exchangers, the entrance is the point at which the cooling water enters the individual heat exchanger or group of heat exchangers, and the...

  16. 40 CFR 63.1409 - Heat exchange system provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and exits each heat exchanger or any combination of heat exchangers. (i) For samples taken at the... entrance and exit of each heat exchanger or any combination of heat exchangers, the entrance is the point at which the cooling water enters the individual heat exchanger or group of heat exchangers, and the...

  17. Comparative analysis of compact heat exchangers for application as the intermediate heat exchanger for advanced nuclear reactors

    DOE PAGES

    Bartel, N.; Chen, M.; Utgikar, V. P.; ...

    2015-04-04

    A comparative evaluation of alternative compact heat exchanger designs for use as the intermediate heat exchanger in advanced nuclear reactor systems is presented in this article. Candidate heat exchangers investigated included the Printed circuit heat exchanger (PCHE) and offset strip-fin heat exchanger (OSFHE). Both these heat exchangers offer high surface area to volume ratio (a measure of compactness [m2/m3]), high thermal effectiveness, and overall low pressure drop. Helium–helium heat exchanger designs for different heat exchanger types were developed for a 600 MW thermal advanced nuclear reactor. The wavy channel PCHE with a 15° pitch angle was found to offer optimummore » combination of heat transfer coefficient, compactness and pressure drop as compared to other alternatives. The principles of the comparative analysis presented here will be useful for heat exchanger evaluations in other applications as well.« less

  18. Comparative analysis of compact heat exchangers for application as the intermediate heat exchanger for advanced nuclear reactors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bartel, N.; Chen, M.; Utgikar, V. P.

    A comparative evaluation of alternative compact heat exchanger designs for use as the intermediate heat exchanger in advanced nuclear reactor systems is presented in this article. Candidate heat exchangers investigated included the Printed circuit heat exchanger (PCHE) and offset strip-fin heat exchanger (OSFHE). Both these heat exchangers offer high surface area to volume ratio (a measure of compactness [m2/m3]), high thermal effectiveness, and overall low pressure drop. Helium–helium heat exchanger designs for different heat exchanger types were developed for a 600 MW thermal advanced nuclear reactor. The wavy channel PCHE with a 15° pitch angle was found to offer optimummore » combination of heat transfer coefficient, compactness and pressure drop as compared to other alternatives. The principles of the comparative analysis presented here will be useful for heat exchanger evaluations in other applications as well.« less

  19. COUPLING

    DOEpatents

    Hawke, B.C.

    1963-02-26

    This patent relates to a releasable coupling connecting a control rod to a control rod drive. This remotely operable coupling mechanism can connect two elements which are laterally and angviarly misaligned, and provides a means for sensing the locked condition of the elements. The coupling utilizes a spherical bayonet joint which is locked against rotation by a ball detent lock. (AEC)

  20. Method for controlling exhaust gas heat recovery systems in vehicles

    DOEpatents

    Spohn, Brian L.; Claypole, George M.; Starr, Richard D

    2013-06-11

    A method of operating a vehicle including an engine, a transmission, an exhaust gas heat recovery (EGHR) heat exchanger, and an oil-to-water heat exchanger providing selective heat-exchange communication between the engine and transmission. The method includes controlling a two-way valve, which is configured to be set to one of an engine position and a transmission position. The engine position allows heat-exchange communication between the EGHR heat exchanger and the engine, but does not allow heat-exchange communication between the EGHR heat exchanger and the oil-to-water heat exchanger. The transmission position allows heat-exchange communication between the EGHR heat exchanger, the oil-to-water heat exchanger, and the engine. The method also includes monitoring an ambient air temperature and comparing the monitored ambient air temperature to a predetermined cold ambient temperature. If the monitored ambient air temperature is greater than the predetermined cold ambient temperature, the two-way valve is set to the transmission position.

  1. Inverse problem and variation method to optimize cascade heat exchange network in central heating system

    NASA Astrophysics Data System (ADS)

    Zhang, Yin; Wei, Zhiyuan; Zhang, Yinping; Wang, Xin

    2017-12-01

    Urban heating in northern China accounts for 40% of total building energy usage. In central heating systems, heat is often transferred from heat source to users by the heat network where several heat exchangers are installed at heat source, substations and terminals respectively. For given overall heating capacity and heat source temperature, increasing the terminal fluid temperature is an effective way to improve the thermal performance of such cascade heat exchange network for energy saving. In this paper, the mathematical optimization model of the cascade heat exchange network with three-stage heat exchangers in series is established. Aim at maximizing the cold fluid temperature for given hot fluid temperature and overall heating capacity, the optimal heat exchange area distribution and the medium fluids' flow rates are determined through inverse problem and variation method. The preliminary results show that the heat exchange areas should be distributed equally for each heat exchanger. It also indicates that in order to improve the thermal performance of the whole system, more heat exchange areas should be allocated to the heat exchanger where flow rate difference between two fluids is relatively small. This work is important for guiding the optimization design of practical cascade heating systems.

  2. 40 CFR 63.1409 - Heat exchange system provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... locations where the cooling water enters and exits each heat exchanger or any combination of heat exchangers.... (iii) For samples taken at the entrance and exit of each heat exchanger or any combination of heat exchangers, the entrance is the point at which the cooling water enters the individual heat exchanger or...

  3. 40 CFR 63.1409 - Heat exchange system provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... locations where the cooling water enters and exits each heat exchanger or any combination of heat exchangers.... (iii) For samples taken at the entrance and exit of each heat exchanger or any combination of heat exchangers, the entrance is the point at which the cooling water enters the individual heat exchanger or...

  4. Pressurized bellows flat contact heat exchanger interface

    NASA Technical Reports Server (NTRS)

    Voss, Fred E. (Inventor); Howell, Harold R. (Inventor); Winkler, Roger V. (Inventor)

    1990-01-01

    Disclosed is an interdigitated plate-type heat exchanger interface. The interface includes a modular interconnect to thermally connect a pair or pairs of plate-type heat exchangers to a second single or multiple plate-type heat exchanger. The modular interconnect comprises a series of parallel, plate-type heat exchangers arranged in pairs to form a slot therebetween. The plate-type heat exchangers of the second heat exchanger insert into the slots of the modular interconnect. Bellows are provided between the pairs of fins of the modular interconnect so that when the bellows are pressurized, they drive the plate-type heat exchangers of the modular interconnect toward one another, thus closing upon the second heat exchanger plates. Each end of the bellows has a part thereof a thin, membrane diaphragm which readily conforms to the contours of the heat exchanger plates of the modular interconnect when the bellows is pressurized. This ensures an even distribution of pressure on the heat exchangers of the modular interconnect thus creating substantially planar contact between the two heat exchangers. The effect of the interface of the present invention is to provide a dry connection between two heat exchangers whereby the rate of heat transfer can be varied by varying the pressure within the bellows.

  5. Spray generators for absorption refrigeration systems

    DOEpatents

    Sibley, Howard W.

    1979-06-19

    A spray generator for an absorption refrigeration system that includes a heat exchanger comprised of a multiplicity of variably spaced heat exchange tubes. The tubes are spaced close together near the top of the heat exchanger and spaced more widely apart near the bottom of the heat exchanger. Dilute absorbent solution is sprayed down through the heat exchanger. The close nesting of the tubes in the top portion of the heat exchanger retards liquid flow and aids heating of the solution. The wide spacing of the tubes in the lower section of the heat exchanger facilitate vapor flow out of the heat exchanger and eliminates liquid "blow-off". The top tubes are covered by a baffle to prevent the liquid solution from splashing out of the heat exchanger off of these top tubes.

  6. 40 CFR 63.1084 - What heat exchange systems are exempt from the requirements of this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 11 2014-07-01 2014-07-01 false What heat exchange systems are exempt... Units: Heat Exchange Systems and Waste Operations Applicability for Heat Exchange Systems § 63.1084 What heat exchange systems are exempt from the requirements of this subpart? Your heat exchange system is...

  7. 40 CFR 63.1084 - What heat exchange systems are exempt from the requirements of this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 11 2013-07-01 2013-07-01 false What heat exchange systems are exempt... Units: Heat Exchange Systems and Waste Operations Applicability for Heat Exchange Systems § 63.1084 What heat exchange systems are exempt from the requirements of this subpart? Your heat exchange system is...

  8. 40 CFR 63.1084 - What heat exchange systems are exempt from the requirements of this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 11 2012-07-01 2012-07-01 false What heat exchange systems are exempt... Units: Heat Exchange Systems and Waste Operations Applicability for Heat Exchange Systems § 63.1084 What heat exchange systems are exempt from the requirements of this subpart? Your heat exchange system is...

  9. 40 CFR 63.1084 - What heat exchange systems are exempt from the requirements of this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 10 2011-07-01 2011-07-01 false What heat exchange systems are exempt... Units: Heat Exchange Systems and Waste Operations Applicability for Heat Exchange Systems § 63.1084 What heat exchange systems are exempt from the requirements of this subpart? Your heat exchange system is...

  10. Secondary Heat Exchanger Design and Comparison for Advanced High Temperature Reactor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Piyush Sabharwall; Ali Siahpush; Michael McKellar

    2012-06-01

    The goals of next generation nuclear reactors, such as the high temperature gas-cooled reactor and advance high temperature reactor (AHTR), are to increase energy efficiency in the production of electricity and provide high temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process heat transport system. The need for efficiency, compactness, and safety challenge the boundaries of existing heat exchanger technology, giving rise to the following study. Various studies have been performed in attempts to update the secondarymore » heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more efficient conversion cycles, such as the Rankine super critical and subcritical cycles. This study considers two different types of heat exchangers—helical coiled heat exchanger and printed circuit heat exchanger—as possible options for the AHTR secondary heat exchangers with the following three different options: (1) A single heat exchanger transfers all the heat (3,400 MW(t)) from the intermediate heat transfer loop to the power conversion system or process plants; (2) Two heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants, each exchanger transfers 1,700 MW(t) with a parallel configuration; and (3) Three heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants. Each heat exchanger transfers 1,130 MW(t) with a parallel configuration. A preliminary cost comparison will be provided for all different cases along with challenges and recommendations.« less

  11. Effectiveness of a heat exchanger in a heat pump clothes dryer

    NASA Astrophysics Data System (ADS)

    Nasution, A. H.; Sembiring, P. G.; Ambarita, H.

    2018-02-01

    This paper deals with study on a heat pump clothes dryer coupled with a heat exchanger. The objective is to explore the effects of the heat exchanger on the performance of the heat pump dryer. The heat pump dryer consists of a vapor compression cycle and integrated with a drying room with volume 1 m3. The power of compressor is 800 Watt and the refrigerant of the cycle is R22. The heat exchanger is a flat plate type with dimensions of 400 mm × 400 mm × 400 mm. The results show the present of the heat exchanger increase the performance of the heat pump dryer. In the present experiment the COP, TP and SMER increase 15.11%, 4.81% and 58.62%, respectively. This is because the heat exchanger provides a better drying condition in the drying room with higher temperature and lower relative humidity in comparison with heat pump dryer without heat exchanger. The effectiveness of the heat exchanger is also high, it is above 50%. It is suggested to install a heat exchanger in a heat pump dryer.

  12. A Review of Industrial Heat Exchange Optimization

    NASA Astrophysics Data System (ADS)

    Yao, Junjie

    2018-01-01

    Heat exchanger is an energy exchange equipment, it transfers the heat from a working medium to another working medium, which has been wildly used in petrochemical industry, HVAC refrigeration, aerospace and so many other fields. The optimal design and efficient operation of the heat exchanger and heat transfer network are of great significance to the process industry to realize energy conservation, production cost reduction and energy consumption reduction. In this paper, the optimization of heat exchanger, optimal algorithm and heat exchanger optimization with different objective functions are discussed. Then, optimization of the heat exchanger and the heat exchanger network considering different conditions are compared and analysed. Finally, all the problems discussed are summarized and foresights are proposed.

  13. Refrigerant charge management in a heat pump water heater

    DOEpatents

    Chen, Jie; Hampton, Justin W.

    2014-06-24

    Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

  14. Identification of Selected Child-Resistant Closures (Continuous Thread, Lug-Bayonet, and Snap Closures).

    ERIC Educational Resources Information Center

    Gross, Rosalind L.; White, Harry E.

    This publication describes a selected group of child-resistant closures used in packaging five categories of medicine and household products. The material in the document was collected to train survey personnel to identify closures for a planned household study of the effectiveness of child-resistant packaging. The 39 closures described are of…

  15. Reliability and Characterization of High Voltage Power Capacitors

    DTIC Science & Technology

    2014-03-01

    Cable The HVPS cable is a specialized coaxial cable that utilizes a high voltage bayonet connector. The cable itself has a voltage rating in excess...the( LabVIEW(program( GPIB( CABLE ( HVPS( HVPS( COAXIAL ( CABLE ( BNC( COAXIAL ( CABLE ( BNC( COAXIAL ( CABLE ( CAPACITOR(‘C’(DATA( CAPACITOR(‘A’(DATA( Circuit...16   F.   CABLES AND CONNECTORS ...................................................................16

  16. Triple loop heat exchanger for an absorption refrigeration system

    DOEpatents

    Reimann, Robert C.

    1984-01-01

    A triple loop heat exchanger for an absorption refrigeration system is disclosed. The triple loop heat exchanger comprises portions of a strong solution line for conducting relatively hot, strong solution from a generator to a solution heat exchanger of the absorption refrigeration system, conduit means for conducting relatively cool, weak solution from the solution heat exchanger to the generator, and a bypass system for conducting strong solution from the generator around the strong solution line and around the solution heat exchanger to an absorber of the refrigeration system when strong solution builds up in the generator to an undesirable level. The strong solution line and the conduit means are in heat exchange relationship with each other in the triple loop heat exchanger so that, during normal operation of the refrigeration system, heat is exchanged between the relatively hot, strong solution flowing through the strong solution line and the relatively cool, weak solution flowing through the conduit means. Also, the strong solution line and the bypass system are in heat exchange relationship in the triple loop heat exchanger so that if the normal flow path of relatively hot, strong solution flowing from the generator to an absorber is blocked, then this relatively, hot strong solution which will then be flowing through the bypass system in the triple loop heat exchanger, is brought into heat exchange relationship with any strong solution which may have solidified in the strong solution line in the triple loop heat exchanger to thereby aid in desolidifying any such solidified strong solution.

  17. Woven heat exchanger

    DOEpatents

    Piscitella, R.R.

    1984-07-16

    This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  18. The study of the mobile compressor unit heat losses recovery system waste heat exchanger thermal insulation types influence on the operational efficiency

    NASA Astrophysics Data System (ADS)

    Yusha, V. L.; Chernov, G. I.; Kalashnikov, A. M.

    2017-08-01

    The paper examines the mobile compressor unit (MCU) heat losses recovery system waste heat exchanger prototype external thermal insulation types influence on the operational efficiency. The study is conducted by means of the numerical method through the modellingof the heat exchange processes carried out in the waste heat exchanger in ANSUS. Thermaflex, mineral wool, penofol, water and air were applied as the heat exchanger external insulation. The study results showed the waste heat exchanger external thermal insulationexistence or absence to have a significant impact on the heat exchanger operational efficiency.

  19. Refrigerant charge management in a heat pump water heater

    DOEpatents

    Chen, Jie; Hampton, Justin W.

    2016-07-05

    Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, and methods of managing refrigerant charge. Various embodiments remove idle refrigerant from a heat exchanger that is not needed for transferring heat by opening a refrigerant recovery valve and delivering the idle refrigerant from the heat exchanger to an inlet port on the compressor. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled by controlling how much refrigerant is drawn from the heat exchanger, by letting some refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and various components can be interconnected with refrigerant conduit. Some embodiments deliver refrigerant gas to the heat exchanger and drive liquid refrigerant out prior to isolating the heat exchanger.

  20. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1983-01-01

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  1. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1977-01-01

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  2. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1983-06-21

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  3. Fabrication of High-Temperature Heat Exchangers by Plasma Spraying Exterior Skins on Nickel Foams

    NASA Astrophysics Data System (ADS)

    Hafeez, P.; Yugeswaran, S.; Chandra, S.; Mostaghimi, J.; Coyle, T. W.

    2016-06-01

    Thermal-sprayed heat exchangers were tested at high temperatures (750 °C), and their performances were compared to the foam heat exchangers made by brazing Inconel sheets to their surface. Nickel foil was brazed to the exterior surface of 10-mm-thick layers of 10 and 40 PPI nickel foam. A plasma torch was used to spray an Inconel coating on the surface of the foil. A burner test rig was built to produce hot combustion gases that flowed over exposed face of the heat exchanger. Cooling air flowed through the foam heat exchanger at rates of up to 200 SLPM. Surface temperature and air inlet/exit temperature were measured. Heat transfer to air flowing through the foam was significantly higher for the thermally sprayed heat exchangers than for the brazed heat exchangers. On an average, thermally sprayed heat exchangers show 36% higher heat transfer than conventionally brazed foam heat exchangers. At low flow rates, the convective resistance is large (~4 × 10-2 m2 K/W), and the effect of thermal contact resistance is negligible. At higher flow rates, the convective resistance decreases (~2 × 10-3 m2 K/W), and the lower contact resistance of the thermally sprayed heat exchanger provides better performance than the brazed heat exchangers.

  4. Diffusion-Welded Microchannel Heat Exchanger for Industrial Processes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Piyush Sabharwall; Denis E. Clark; Michael V. Glazoff

    The goal of next generation reactors is to increase energy ef?ciency in the production of electricity and provide high-temperature heat for industrial processes. The ef?cient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process. The need for ef?ciency, compactness, and safety challenge the boundaries of existing heat exchanger technology. Various studies have been performed in attempts to update the secondary heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more ef?cientmore » industrial processes. Modern compact heat exchangers can provide high compactness, a measure of the ratio of surface area-to-volume of a heat exchange. The microchannel heat exchanger studied here is a plate-type, robust heat exchanger that combines compactness, low pressure drop, high effectiveness, and the ability to operate with a very large pressure differential between hot and cold sides. The plates are etched and thereafter joined by diffusion welding, resulting in extremely strong all-metal heat exchanger cores. After bonding, any number of core blocks can be welded together to provide the required ?ow capacity. This study explores the microchannel heat exchanger and draws conclusions about diffusion welding/bonding for joining heat exchanger plates, with both experimental and computational modeling, along with existing challenges and gaps. Also, presented is a thermal design method for determining overall design speci?cations for a microchannel printed circuit heat exchanger for both supercritical (24 MPa) and subcritical (17 MPa) Rankine power cycles.« less

  5. Heat Exchangers for Utilization of the Heat of High-Temperature Geothermal Brines

    NASA Astrophysics Data System (ADS)

    Alkhasov, A. B.; Alkhasova, D. A.

    2018-03-01

    The basic component of two-circuit geothermal systems is the heat exchanger. When used in geothermal power systems, conventional shell-and-tube and plate heat exchangers cause problems related to the cleaning of the latter from salt-deposition and corrosion products. Their lifetime does not exceed, as a rule, 1 year. To utilize the heat of high-temperature geothermal brines, a heat exchanger of the "tube-in-tube" type is proposed. A heat exchanger of this design has been operated for several years in Ternair geothermal steam field; in this heat exchanger, the thermal potential of the saline thermal water is transferred to the fresh water of the secondary circuit of the heating system for apartment houses. The reduction in the weight and size characteristics of the heat exchangers is a topical problem that can be solved with the help of heat transfer enhancers. To enhance the heat transfer process in the heat exchanger, longitudinal ribbing of the heat exchange surface is proposed. The increase in the heat exchange surface from the heat carrier side by ribbing results in an increase in the amount of the heat transferred from the heating agent. The heat exchanger is easy to manufacture and is assembled out of components comprised of two concentrically positioned tubes of a definite length, 3-6 m, serially connected with each other. The method for calculation of the impact of the number and the size of the longitudinal ribs on the heat transfer in the well heat exchanger is presented and a criterion for the selection of the optimal number and design parameters of the ribs is formulated. To prevent the corrosion and salt deposition in the heat exchanger, the use of an effective OEDFK (oxyethylidenediphosphonic acid) agent is proposed. This agent has a long-lasting corrosion-inhibiting and antiscaling effect, which is explained by the formation of a strongly adhesive chelate layer difficult to wash off the surface. The passivating OEDFK layer is restored by periodical pulsed introduction of the agent solution into the brine at the heat exchanger inlet.

  6. Fault-Tolerant Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Crowley, Christopher J.

    2005-01-01

    A compact, lightweight heat exchanger has been designed to be fault-tolerant in the sense that a single-point leak would not cause mixing of heat-transfer fluids. This particular heat exchanger is intended to be part of the temperature-regulation system for habitable modules of the International Space Station and to function with water and ammonia as the heat-transfer fluids. The basic fault-tolerant design is adaptable to other heat-transfer fluids and heat exchangers for applications in which mixing of heat-transfer fluids would pose toxic, explosive, or other hazards: Examples could include fuel/air heat exchangers for thermal management on aircraft, process heat exchangers in the cryogenic industry, and heat exchangers used in chemical processing. The reason this heat exchanger can tolerate a single-point leak is that the heat-transfer fluids are everywhere separated by a vented volume and at least two seals. The combination of fault tolerance, compactness, and light weight is implemented in a unique heat-exchanger core configuration: Each fluid passage is entirely surrounded by a vented region bridged by solid structures through which heat is conducted between the fluids. Precise, proprietary fabrication techniques make it possible to manufacture the vented regions and heat-conducting structures with very small dimensions to obtain a very large coefficient of heat transfer between the two fluids. A large heat-transfer coefficient favors compact design by making it possible to use a relatively small core for a given heat-transfer rate. Calculations and experiments have shown that in most respects, the fault-tolerant heat exchanger can be expected to equal or exceed the performance of the non-fault-tolerant heat exchanger that it is intended to supplant (see table). The only significant disadvantages are a slight weight penalty and a small decrease in the mass-specific heat transfer.

  7. Multi-zone cooling/warming garment

    NASA Technical Reports Server (NTRS)

    Leon, Gloria R. (Inventor); Koscheyev, Victor S. (Inventor); Dancisak, Michael J. (Inventor)

    2006-01-01

    A thermodynamically efficient garment for cooling and/or heating a human body. The thermodynamic efficiency is provided in part by targeting the heat exchange capabilities of the garment to specific areas and/or structures of the human body. The heat exchange garment includes heat exchange zones and one or more non-heat exchange zones, where the heat exchange zones are configured to correspond to one or more high density tissue areas of the human body when the garment is worn. A system including the garment can be used to exchange heat with the adjacent HD tissue areas under the control of a feedback control system. Sensed physiological parameters received by the feedback control system can be used to adjust the characteristics of heat exchange fluid moving within the heat exchange garment.

  8. 40 CFR 63.104 - Heat exchange system requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  9. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood or...

  10. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood or...

  11. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood or...

  12. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood or...

  13. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood or...

  14. Perspectives of advanced thermal management in solar thermochemical syngas production using a counter-flow solid-solid heat exchanger

    NASA Astrophysics Data System (ADS)

    Falter, Christoph; Sizmann, Andreas; Pitz-Paal, Robert

    2017-06-01

    A modular reactor model is presented for the description of solar thermochemical syngas production involving counter-flow heat exchangers that recuperate heat from the solid phase. The development of the model is described including heat diffusion within the reactive material as it travels through the heat exchanger, which was previously identified to be a possibly limiting factor in heat exchanger design. Heat transfer within the reactive medium is described by conduction and radiation, where the former is modeled with the three-resistor model and the latter with the Rosseland diffusion approximation. The applicability of the model is shown by the analysis of heat exchanger efficiency for different material thicknesses and porosities in a system with 8 chambers and oxidation and reduction temperatures of 1000 K and 1800 K, respectively. Heat exchanger efficiency is found to rise strongly for a reduction of material thickness, as the element mass is reduced and a larger part of the elements takes part in the heat exchange process. An increase of porosity enhances radiation heat exchange but deteriorates conduction. The overall heat exchange in the material is improved for high temperatures in the heat exchanger, as radiation dominates the energy transfer. The model is shown to be a valuable tool for the development and analysis of solar thermochemical reactor concepts involving heat exchange from the solid phase.

  15. CFD analysis of the plate heat exchanger - Mathematical modelling of mass and heat transfer in serial connection with tubular heat exchanger

    NASA Astrophysics Data System (ADS)

    Bojko, Marian; Kocich, Radim

    2016-06-01

    Application of numerical simulations based on the CFD calculation when the mass and heat transfer between the fluid flows is essential component of thermal calculation. In this article the mathematical model of the heat exchanger is defined, which is subsequently applied to the plate heat exchanger, which is connected in series with the other heat exchanger (tubular heat exchanger). The present contribution deals with the possibility to use the waste heat of the flue gas produced by small micro turbine. Inlet boundary conditions to the mathematical model of the plate heat exchanger are obtained from the results of numerical simulation of the tubular heat exchanger. Required parameters such for example inlet temperature was evaluated from temperature field, which was subsequently imported to the inlet boundary condition to the simulation of plate heat exchanger. From the results of 3D numerical simulations are evaluated basic flow variables including the evaluation of dimensionless parameters such as Colburn j-factor and friction ft factor. Numerical simulation is realized by software ANSYS Fluent15.0.

  16. Woven heat exchanger

    DOEpatents

    Piscitella, Roger R.

    1987-01-01

    In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  17. 40 CFR 63.1083 - Does this subpart apply to my heat exchange system?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CATEGORIES (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Applicability for Heat Exchange Systems § 63.1083 Does this subpart apply to my heat exchange system? The provisions of this subpart apply to your heat exchange system if you own...

  18. 40 CFR 63.1083 - Does this subpart apply to my heat exchange system?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CATEGORIES (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Applicability for Heat Exchange Systems § 63.1083 Does this subpart apply to my heat exchange system? The provisions of this subpart apply to your heat exchange system if you own...

  19. 40 CFR 63.1083 - Does this subpart apply to my heat exchange system?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CATEGORIES (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Applicability for Heat Exchange Systems § 63.1083 Does this subpart apply to my heat exchange system? The provisions of this subpart apply to your heat exchange system if you own...

  20. 40 CFR 63.1083 - Does this subpart apply to my heat exchange system?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CATEGORIES (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Applicability for Heat Exchange Systems § 63.1083 Does this subpart apply to my heat exchange system? The provisions of this subpart apply to your heat exchange system if you own...

  1. Woven heat exchanger

    DOEpatents

    Piscitella, Roger R.

    1987-05-05

    In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  2. Heat exchanger containing a component capable of discontinuous movement

    DOEpatents

    Wilson, D.G.

    1993-11-09

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices. 11 figures.

  3. Heat exchanger containing a component capable of discontinuous movement

    DOEpatents

    Wilson, David Gordon

    2001-04-17

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  4. Heat exchanger containing a component capable of discontinuous movement

    DOEpatents

    Wilson, David G.

    1993-01-01

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  5. Heat exchanger containing a component capable of discontinuous movement

    DOEpatents

    Wilson, David Gordon

    2002-01-01

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  6. Test results of a Stirling engine utilizing heat exchanger modules with an integral heat pipe

    NASA Astrophysics Data System (ADS)

    Skupinski, Robert C.; Tower, Leonard K.; Madi, Frank J.; Brusk, Kevin D.

    1993-04-01

    The Heat Pipe Stirling Engine (HP-1000), a free-piston Stirling engine incorporating three heat exchanger modules, each having a sodium filled heat pipe, has been tested at the NASA-Lewis Research Center as part of the Civil Space Technology Initiative (CSTI). The heat exchanger modules were designed to reduce the number of potential flow leak paths in the heat exchanger assembly and incorporate a heat pipe as the link between the heat source and the engine. An existing RE-1000 free-piston Stirling engine was modified to operate using the heat exchanger modules. This paper describes heat exchanger module and engine performance during baseline testing. Condenser temperature profiles, brake power, and efficiency are presented and discussed.

  7. Test results of a Stirling engine utilizing heat exchanger modules with an integral heat pipe

    NASA Technical Reports Server (NTRS)

    Skupinski, Robert C.; Tower, Leonard K.; Madi, Frank J.; Brusk, Kevin D.

    1993-01-01

    The Heat Pipe Stirling Engine (HP-1000), a free-piston Stirling engine incorporating three heat exchanger modules, each having a sodium filled heat pipe, has been tested at the NASA-Lewis Research Center as part of the Civil Space Technology Initiative (CSTI). The heat exchanger modules were designed to reduce the number of potential flow leak paths in the heat exchanger assembly and incorporate a heat pipe as the link between the heat source and the engine. An existing RE-1000 free-piston Stirling engine was modified to operate using the heat exchanger modules. This paper describes heat exchanger module and engine performance during baseline testing. Condenser temperature profiles, brake power, and efficiency are presented and discussed.

  8. QUICK DISCONNECT ELECTRICAL CONNECTOR

    DOEpatents

    None

    1962-08-14

    A remotely actuated quick-dlsconnect electrical connector which comprises a pair of mating portrons releasably retained together by a bayonet- type joint with a rotatable sleeve on one of the mating portions providing for engagement and disengagement of the joint is described. A lanyard with ends passed through fulcrums and affixed to the sleeve erfects rotation of the sleeve and disengages the joint. (AEC)

  9. 40 CFR Table 6 to Subpart Hhhhh of... - Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Requirements for Heat Exchange Systems... Manufacturing Pt. 63, Subpt. HHHHH, Table 6 Table 6 to Subpart HHHHH of Part 63—Requirements for Heat Exchange... your heat exchange systems. For each . . . You must . . . Heat exchange system, as defined in § 63.101...

  10. 40 CFR Table 6 to Subpart Hhhhh of... - Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 14 2014-07-01 2014-07-01 false Requirements for Heat Exchange Systems... Manufacturing Pt. 63, Subpt. HHHHH, Table 6 Table 6 to Subpart HHHHH of Part 63—Requirements for Heat Exchange... your heat exchange systems. For each . . . You must . . . Heat exchange system, as defined in § 63.101...

  11. 40 CFR Table 6 to Subpart Hhhhh of... - Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 14 2012-07-01 2011-07-01 true Requirements for Heat Exchange Systems... Manufacturing Pt. 63, Subpt. HHHHH, Table 6 Table 6 to Subpart HHHHH of Part 63—Requirements for Heat Exchange... your heat exchange systems. For each . . . You must . . . Heat exchange system, as defined in § 63.101...

  12. 40 CFR Table 6 to Subpart Hhhhh of... - Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 14 2013-07-01 2013-07-01 false Requirements for Heat Exchange Systems... Manufacturing Pt. 63, Subpt. HHHHH, Table 6 Table 6 to Subpart HHHHH of Part 63—Requirements for Heat Exchange... your heat exchange systems. For each . . . You must . . . Heat exchange system, as defined in § 63.101...

  13. 40 CFR Table 6 to Subpart Hhhhh of... - Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 13 2011-07-01 2011-07-01 false Requirements for Heat Exchange Systems... Manufacturing Pt. 63, Subpt. HHHHH, Table 6 Table 6 to Subpart HHHHH of Part 63—Requirements for Heat Exchange... your heat exchange systems. For each . . . You must . . . Heat exchange system, as defined in § 63.101...

  14. Modular Heat Exchanger With Integral Heat Pipe

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.

    1992-01-01

    Modular heat exchanger with integral heat pipe transports heat from source to Stirling engine. Alternative to heat exchangers depending on integrities of thousands of brazed joints, contains only 40 brazed tubes.

  15. Information technology equipment cooling system

    DOEpatents

    Schultz, Mark D.

    2014-06-10

    According to one embodiment, a system for removing heat from a rack of information technology equipment may include a sidecar indoor air to liquid heat exchanger that cools warm air generated by the rack of information technology equipment. The system may also include a liquid to liquid heat exchanger and an outdoor heat exchanger. The system may further include configurable pathways to connect and control fluid flow through the sidecar heat exchanger, the liquid to liquid heat exchanger, the rack of information technology equipment, and the outdoor heat exchanger based upon ambient temperature and/or ambient humidity to remove heat from the rack of information technology equipment.

  16. Determination of Ground Heat Exchangers Temperature Field in Geothermal Heat Pumps

    NASA Astrophysics Data System (ADS)

    Zhurmilova, I.; Shtym, A.

    2017-11-01

    For the heating and cooling supply of buildings and constructions geothermal heat pumps using low-potential ground energy are applied by means of ground exchangers. The process of heat transfer in a system of ground exchangers is a phenomenon of complex heat transfer. The paper presents a mathematical modeling of heat exchange processes, the temperature fields are built which are necessary for the determination of the ground array that ensures an adequate supply of low potential energy excluding the freezing of soil around the pipes in the ground heat exchangers and guaranteeing a reliable operation of geothermal heat pumps.

  17. Numerical simulation of tubes-in-tube heat exchanger in a mixed refrigerant Joule-Thomson cryocooler

    NASA Astrophysics Data System (ADS)

    Damle, R. M.; Ardhapurkar, P. M.; Atrey, M. D.

    2017-02-01

    Mixed refrigerant Joule-Thomson (MRJT) cryocoolers can produce cryogenic temperatures with high efficiency and low operating pressures. As compared to the high system pressures of around 150-200 bar with nitrogen, the operational pressures with non-azeotropic mixtures (e.g., nitrogen-hydrocarbons) come down to 10-25 bar. With mixtures, the heat transfer in the recuperative heat exchanger takes place in the two-phase region. The simultaneous boiling and condensation of the cold and hot gas streams lead to higher heat transfer coefficients as compared to single phase heat exchange. The two-phase heat transfer in the recuperative heat exchanger drastically affects the performance of a MRJT cryocooler. In this work, a previously reported numerical model for a simple tube-in-tube heat exchanger is extended to a multi tubes-in-tube heat exchanger with a transient formulation. Additionally, the J-T expansion process is also considered to simulate the cooling process of the heat exchanger from ambient temperature conditions. A tubes-in-tube heat exchanger offers more heat transfer area per unit volume resulting in a compact design. Also, the division of flow in multiple tubes reduces the pressure drop in the heat exchanger. Simulations with different mixtures of nitrogen-hydrocarbons are carried out and the numerical results are compared with the experimental data.

  18. Experimental investigation of heat transfer and effectiveness in corrugated plate heat exchangers having different chevron angles

    NASA Astrophysics Data System (ADS)

    Kılıç, Bayram; İpek, Osman

    2017-02-01

    In this study, heat transfer rate and effectiveness of corrugated plate heat exchangers having different chevron angles were investigated experimentally. Chevron angles of plate heat exchangers are β = 30° and β = 60°. For this purpose, experimentally heating system used plate heat exchanger was designed and constructed. Thermodynamic analysis of corrugated plate heat exchangers having different chevron angles were carried out. The heat transfer rate and effectiveness values are calculated. The experimental results are shown that heat transfer rate and effectiveness values for β = 60° is higher than that of the other. Obtained experimental results were graphically presented.

  19. Lightweight Long Life Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Moore, E. K.

    1976-01-01

    A shuttle orbiter flight configuration aluminum heat exchanger was designed, fabricated, and tested. The heat exchanger utilized aluminum clad titanium composite parting sheets for protection against parting sheet pin hole corrosion. The heat exchanger, which is fully interchangeable with the shuttle condensing heat exchanger, includes slurpers (a means for removing condensed water from the downstream face of the heat exchanger), and both the core air passes and slurpers were hydrophilic coated to enhance wettability. The test program included performance tests which demonstrated the adequacy of the design and confirmed the predicted weight savings.

  20. 14 CFR 29.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Exhaust heat exchangers. 29.1125 Section 29... exchangers. For reciprocating engine powered rotorcraft the following apply: (a) Each exhaust heat exchanger... is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff may have stagnant...

  1. 14 CFR 29.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Exhaust heat exchangers. 29.1125 Section 29... exchangers. For reciprocating engine powered rotorcraft the following apply: (a) Each exhaust heat exchanger... is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff may have stagnant...

  2. 14 CFR 25.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Exhaust heat exchangers. 25.1125 Section 25... exchangers. For reciprocating engine powered airplanes, the following apply: (a) Each exhaust heat exchanger... provisions wherever it is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff...

  3. 14 CFR 25.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Exhaust heat exchangers. 25.1125 Section 25... exchangers. For reciprocating engine powered airplanes, the following apply: (a) Each exhaust heat exchanger... provisions wherever it is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff...

  4. 14 CFR 29.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Exhaust heat exchangers. 29.1125 Section 29... exchangers. For reciprocating engine powered rotorcraft the following apply: (a) Each exhaust heat exchanger... is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff may have stagnant...

  5. 14 CFR 25.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Exhaust heat exchangers. 25.1125 Section 25... exchangers. For reciprocating engine powered airplanes, the following apply: (a) Each exhaust heat exchanger... provisions wherever it is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff...

  6. 14 CFR 25.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Exhaust heat exchangers. 25.1125 Section 25... exchangers. For reciprocating engine powered airplanes, the following apply: (a) Each exhaust heat exchanger... provisions wherever it is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff...

  7. 14 CFR 29.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Exhaust heat exchangers. 29.1125 Section 29... exchangers. For reciprocating engine powered rotorcraft the following apply: (a) Each exhaust heat exchanger... is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff may have stagnant...

  8. 14 CFR 25.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Exhaust heat exchangers. 25.1125 Section 25... exchangers. For reciprocating engine powered airplanes, the following apply: (a) Each exhaust heat exchanger... provisions wherever it is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff...

  9. 14 CFR 29.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Exhaust heat exchangers. 29.1125 Section 29... exchangers. For reciprocating engine powered rotorcraft the following apply: (a) Each exhaust heat exchanger... is subject to contact with exhaust gases; and (4) No exhaust heat exchanger or muff may have stagnant...

  10. Experimental study on heat transfer performance of fin-tube exchanger and PSHE for waste heat recovery

    NASA Astrophysics Data System (ADS)

    Chen, Ting; Bae, Kyung Jin; Kwon, Oh Kyung

    2018-02-01

    In this paper, heat transfer characteristics of fin-tube heat exchanger and primary surface heat exchanger (PSHE) used in waste heat recovery were investigated experimentally. The flow in the fin-tube heat exchanger is cross flow and in PSHE counter flow. The variations of friction factor and Colburn j factor with air mass flow rate, and Nu number with Re number are presented. Various comparison methods are used to evaluate heat transfer performance, and the results show that the heat transfer rate of the PSHE is on average 17.3% larger than that of fin-tube heat exchanger when air mass flow rate is ranging from 1.24 to 3.45 kg/min. However, the PSHE causes higher pressure drop, and the fin-tube heat exchanger has a wider application range which leads to a 31.7% higher value of maximum heat transfer rate compared to that of the PSHE. Besides, under the same fan power per unit frontal surface, a higher heat transfer rate value is given in the fin-tube heat exchanger.

  11. The solution of private problems for optimization heat exchangers parameters

    NASA Astrophysics Data System (ADS)

    Melekhin, A.

    2017-11-01

    The relevance of the topic due to the decision of problems of the economy of resources in heating systems of buildings. To solve this problem we have developed an integrated method of research which allows solving tasks on optimization of parameters of heat exchangers. This method decides multicriteria optimization problem with the program nonlinear optimization on the basis of software with the introduction of an array of temperatures obtained using thermography. The author have developed a mathematical model of process of heat exchange in heat exchange surfaces of apparatuses with the solution of multicriteria optimization problem and check its adequacy to the experimental stand in the visualization of thermal fields, an optimal range of managed parameters influencing the process of heat exchange with minimal metal consumption and the maximum heat output fin heat exchanger, the regularities of heat exchange process with getting generalizing dependencies distribution of temperature on the heat-release surface of the heat exchanger vehicles, defined convergence of the results of research in the calculation on the basis of theoretical dependencies and solving mathematical model.

  12. Information technology equipment cooling method

    DOEpatents

    Schultz, Mark D.

    2015-10-20

    According to one embodiment, a system for removing heat from a rack of information technology equipment may include a sidecar indoor air to liquid heat exchanger that cools air utilized by the rack of information technology equipment to cool the rack of information technology equipment. The system may also include a liquid to liquid heat exchanger and an outdoor heat exchanger. The system may further include configurable pathways to connect and control fluid flow through the sidecar heat exchanger, the liquid to liquid heat exchanger, the rack of information technology equipment, and the outdoor heat exchanger based upon ambient temperature and/or ambient humidity to remove heat generated by the rack of information technology equipment.

  13. Dual Expander Cycle Rocket Engine with an Intermediate, Closed-cycle Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Greene, William D. (Inventor)

    2008-01-01

    A dual expander cycle (DEC) rocket engine with an intermediate closed-cycle heat exchanger is provided. A conventional DEC rocket engine has a closed-cycle heat exchanger thermally coupled thereto. The heat exchanger utilizes heat extracted from the engine's fuel circuit to drive the engine's oxidizer turbomachinery.

  14. Fluidized bed heat exchanger with water cooled air distributor and dust hopper

    DOEpatents

    Jukkola, Walfred W.; Leon, Albert M.; Van Dyk, Jr., Garritt C.; McCoy, Daniel E.; Fisher, Barry L.; Saiers, Timothy L.; Karstetter, Marlin E.

    1981-11-24

    A fluidized bed heat exchanger is provided in which air is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat exchange and the housing of the heat exchanger has a water-wall type construction. Vertical in-bed heat exchange tubes are provided and the air distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat exchange tubes are provided to extract heat from the exiting combustion gases.

  15. 40 CFR 63.1085 - What are the general requirements for heat exchange systems?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... heat exchange systems? 63.1085 Section 63.1085 Protection of Environment ENVIRONMENTAL PROTECTION... Exchange Systems and Waste Operations Heat Exchange System Requirements § 63.1085 What are the general requirements for heat exchange systems? Unless you meet one of the requirements for exemptions in § 63.1084...

  16. 40 CFR 63.1085 - What are the general requirements for heat exchange systems?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... heat exchange systems? 63.1085 Section 63.1085 Protection of Environment ENVIRONMENTAL PROTECTION... Exchange Systems and Waste Operations Heat Exchange System Requirements § 63.1085 What are the general requirements for heat exchange systems? Unless you meet one of the requirements for exemptions in § 63.1084...

  17. 40 CFR 63.1085 - What are the general requirements for heat exchange systems?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... heat exchange systems? 63.1085 Section 63.1085 Protection of Environment ENVIRONMENTAL PROTECTION... Exchange Systems and Waste Operations Heat Exchange System Requirements § 63.1085 What are the general requirements for heat exchange systems? Unless you meet one of the requirements for exemptions in § 63.1084...

  18. 40 CFR 63.1085 - What are the general requirements for heat exchange systems?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... heat exchange systems? 63.1085 Section 63.1085 Protection of Environment ENVIRONMENTAL PROTECTION... Exchange Systems and Waste Operations Heat Exchange System Requirements § 63.1085 What are the general requirements for heat exchange systems? Unless you meet one of the requirements for exemptions in § 63.1084...

  19. High temperature heat exchangers for gas turbines and future hypersonic air breathing propulsion

    NASA Astrophysics Data System (ADS)

    Avran, Patrick; Bernard, Pierre

    After surveying the results of ONERA's investigations to date of metallic and ceramic heat exchangers applicable to automotive and aircraft powerplants, which are primarily of finned-tube counterflow configuration, attention is given to the influence of heat-exchanger effectiveness on fuel consumption and exchanger dimensions and weight. Emphasis is placed on the results of studies of cryogenic heat exchangers used by airbreathing hypersonic propulsion systems. The numerical codes developed by ONERA for the modeling of heat exchanger thermodynamics are evaluated.

  20. Architecture for Absorption Based Heaters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moghaddam, Saeed; Chugh, Devesh

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

  1. Finite element method (FEM) analysis of the force systems produced by asymmetric inner headgear bows.

    PubMed

    Geramy, Allahyar; Kizilova, Natalya; Terekhov, Leonid

    2011-11-01

    Extra-oral traction appliances were introduced more than a century ago and continue to be used to produce orthopaedic and/or dental changes in the maxilla. While force systems produced by asymmetric outer bows have been studied extensively, the force systems produced by asymmetric inner bows have been overlooked. To analyse the forces acting on the maxillary first molars: when the size of one bayonet bend is increased; when the point of application of the distalising force on the inner bow is moved to one side; when one molar is displaced palatally. Four FEM models of cervical headgear attached to maxillary first molars were designed in SolidWorks 2010 and transferred to an ANSYS Workbench Ver. 12.1. Model 1, each molar was 23 mm from the midpalatal line and the inner bow was symmetrical; Model 2, the left molar was displaced 4 mm towards the midpalatal line and the inner bow was symmetrical; Model 3, the molars were equidistant (23 mm) from the midpalatal line, but the left molar was engaged by a 2 mm larger bayonet bend; Model 4, the molars were equidistant (23 mm) from the midpalatal line but the join between the inner and outer bows was displaced 2 mm towards the left molar. In all FEM models, a 2N force was applied to the inner bow at the join between inner and outer bows and the energy transmitted to the teeth and the von Mises stresses on the molar PDLs were assessed. There were marked differences in the strain energy on the teeth and the von Mises stresses on their PDLs. A 14 to 20 per cent increase in energy and force was produced on the tooth closer to the symmetric plane of the headgear. In addition, the increase in energy produced a 30 to 62 per cent increase in the von Mises stresses within the PDLs. Small asymmetries in molar position, the size of a bayonet bend and the point of application of a force on an inner bow resulted in asymmetrical forces on the molars. These forces were higher on the molar closer to the symmetric plane of the headgear.

  2. High-temperature self-circulating thermoacoustic heat exchanger

    NASA Astrophysics Data System (ADS)

    Backhaus, S.; Swift, G. W.; Reid, R. S.

    2005-07-01

    Thermoacoustic and Stirling engines and refrigerators use heat exchangers to transfer heat between the oscillating flow of their thermodynamic working fluids and external heat sources and sinks. An acoustically driven heat-exchange loop uses an engine's own pressure oscillations to steadily circulate its own thermodynamic working fluid through a physically remote high-temperature heat source without using moving parts, allowing for a significant reduction in the cost and complexity of thermoacoustic and Stirling heat exchangers. The simplicity and flexibility of such heat-exchanger loops will allow thermoacoustic and Stirling machines to access diverse heat sources and sinks. Measurements of the temperatures at the interface between such a heat-exchange loop and the hot end of a thermoacoustic-Stirling engine are presented. When the steady flow is too small to flush out the mixing chamber in one acoustic cycle, the heat transfer to the regenerator is excellent, with important implications for practical use.

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feng, Yinshan; Wang, Jinliang; Zhao, Futao

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

  4. Study of fuel cell powerplant with heat recovery

    NASA Technical Reports Server (NTRS)

    King, J. M.; Grasso, A. P.; Clausi, J. V.

    1975-01-01

    It was shown that heat can be recovered from fuel cell power plants by replacing the air-cooled heat exchangers in present designs with units which transfer the heat to the integrated utility system. Energy availability for a 40-kW power plant was studied and showed that the total usable energy at rated power represents 84 percent of the fuel lower heating value. The effects of design variables on heat availability proved to be small. Design requirements were established for the heat recovery heat exchangers, including measurement of the characteristics of two candidate fuel cell coolants after exposure to fuel cell operating conditions. A heat exchanger test program was defined to assess fouling and other characteristics of fuel cell heat exchangers needed to confirm heat exchanger designs for heat recovery.

  5. ETR HEAT EXCHANGER BUILDING, TRA644. WORKERS ARE INSTALLING HEAT EXCHANGER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ETR HEAT EXCHANGER BUILDING, TRA-644. WORKERS ARE INSTALLING HEAT EXCHANGER PIPING. INL NEGATIVE NO. 56-3122. Jack L. Anderson, Photographer, 9/21/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. Heat pump having improved defrost system

    DOEpatents

    Chen, Fang C.; Mei, Viung C.; Murphy, Richard W.

    1998-01-01

    A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger.

  7. Heat pump having improved defrost system

    DOEpatents

    Chen, F.C.; Mei, V.C.; Murphy, R.W.

    1998-12-08

    A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger. 2 figs.

  8. Design of distributed JT (Joule-Thomson) effect heat exchanger for superfluid 2 K cooling device

    NASA Astrophysics Data System (ADS)

    Jeong, S.; Park, C.; Kim, K.

    2018-03-01

    Superfluid at 2 K or below is readily obtained from liquid helium at 4.2 K by reducing its vapour pressure. For better cooling performance, however, the cold energy of vaporized helium at 2 K chamber can be effectively utilized in a recuperator which is specially designed in this paper for accomplishing so-called the distributed Joule-Thomson (JT) expansion effect. This paper describes the design methodology of distributed JT effect heat exchanger for 2 K JT cooling device. The newly developed heat exchanger allows continuous significant pressure drop at high-pressure part of the recuperative heat exchanger by using a capillary tube. Being different from conventional recuperative heat exchangers, the efficient JT effect HX must consider the pressure drop effect as well as the heat transfer characteristic. The heat exchanger for the distributed JT effect actively utilizes continuous pressure loss at the hot stream of the heat exchanger by using an OD of 0.64 mm and an ID of 0.4 mm capillary tube. The analysis is performed by dividing the heat exchanger into the multiple sub-units of the heat exchange part and JT valve. For more accurate estimation of the pressure drop of spirally wound capillary tube, preliminary experiments are carried out to investigate the friction factor at high Reynolds number. By using the developed pressure drop correlation and the heat transfer correlation, the specification of the heat exchanger with distributed JT effect for 2 K JT refrigerator is determined.

  9. High Efficiency Heat Exchanger for High Temperature and High Pressure Applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sienicki, James J.; Lv, Qiuping; Moisseytsev, Anton

    CompRex, LLC (CompRex) specializes in the design and manufacture of compact heat exchangers and heat exchange reactors for high temperature and high pressure applications. CompRex’s proprietary compact technology not only increases heat exchange efficiency by at least 25 % but also reduces footprint by at least a factor of ten compared to traditional shell-and-tube solutions of the same capacity and by 15 to 20 % compared to other currently available Printed Circuit Heat Exchanger (PCHE) solutions. As a result, CompRex’s solution is especially suitable for Brayton cycle supercritical carbon dioxide (sCO2) systems given its high efficiency and significantly lower capitalmore » and operating expenses. CompRex has already successfully demonstrated its technology and ability to deliver with a pilot-scale compact heat exchanger that was under contract by the Naval Nuclear Laboratory for sCO2 power cycle development. The performance tested unit met or exceeded the thermal and hydraulic specifications with measured heat transfer between 95 to 98 % of maximum heat transfer and temperature and pressure drop values all consistent with the modeled values. CompRex’s vision is to commercialize its compact technology and become the leading provider for compact heat exchangers and heat exchange reactors for various applications including Brayton cycle sCO2 systems. One of the limitations of the sCO2 Brayton power cycle is the design and manufacturing of efficient heat exchangers at extreme operating conditions. Current diffusion-bonded heat exchangers have limitations on the channel size through which the fluid travels, resulting in excessive solid material per heat exchanger volume. CompRex’s design allows for more open area and shorter fluid proximity for increased heat transfer efficiency while sustaining the structural integrity needed for the application. CompRex is developing a novel improvement to its current heat exchanger design where fluids are directed to alternating channels so that each fluid is fully surrounded by the opposing fluid. As compared to similar existing compact heat exchangers, the new design converts most secondary surface area to primary surface area, eliminating fin inefficiencies. CompRex requests that all technical information about the heat exchanger designs be protected as proprietary information. To honor that request, only non-proprietay summaries are included in this report.« less

  10. Increasing the Efficiency of Maple Sap Evaporators with Heat Exchangers

    Treesearch

    Lawrence D. Garrett; Howard Duchacek; Mariafranca Morselli; Frederick M. Laing; Neil K. Huyler; James W. Marvin

    1977-01-01

    A study of the engineering and economic effects of heat exchangers in conventional maple syrup evaporators indicated that: (1) Efficiency was increased by 15 to 17 percent with heat exchangers; (2) Syrup produced in evaporators with heat exchangers was similar to syrup produced in conventional systems in flavor and in chemical and physical composition; and (3) Heat...

  11. Device for cooling and humidifying reformate

    DOEpatents

    Zhao, Jian Lian; Northrop, William F.

    2008-04-08

    Devices for cooling and humidifying a reformate stream from a reforming reactor as well as related methods, modules and systems includes a heat exchanger and a sprayer. The heat exchanger has an inlet, an outlet, and a conduit between the inlet and the outlet. The heat exchanger is adapted to allow a flow of a first fluid (e.g. water) inside the conduit and to establish a heat exchange relationship between the first fluid and a second fluid (e.g. reformate from a reforming reactor) flowing outside the conduit. The sprayer is coupled to the outlet of the heat exchanger for spraying the first fluid exiting the heat exchanger into the second fluid.

  12. Preliminary design package for maxi-therm heat exchanger module

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Heat exchangers were developed for use in a solar heating and cooling system installed in a single family dwelling. Each of the three exchangers consisted of a heating and cooling module and a submersed electric water heating element. Information necessary to evaluate the preliminary design of the heat exchanger is presented in terms of the development and verification plans, performance specifications, installation and maintenance, and hazard analysis.

  13. The Effects of the Heat and Moisture Exchanger on Humidity, Airway Temperature, and Core Body Temperature

    DTIC Science & Technology

    1999-10-01

    measurement was made a heat and moisture exchanger was added to the experimental group. Three more measurements were recorded at 10, 30 and 60 minutes after...system was insufficient, but the addition of a heat and moisture exchanger provided adequate humidification of the inspired gases. In the experimental ...of these patients had a heat and moisture exchanger incorporated in the ventilator Heat and Moisture Exchangers 16 circuit (the experimental group

  14. Prototype Vent Gas Heat Exchanger for Exploration EVA - Performance and Manufacturing Characteristics

    NASA Technical Reports Server (NTRS)

    Quinn, Gregory J.; Strange, Jeremy; Jennings, Mallory

    2013-01-01

    NASA is developing new portable life support system (PLSS) technologies, which it is demonstrating in an unmanned ground based prototype unit called PLSS 2.0. One set of technologies within the PLSS provides suitable ventilation to an astronaut while on an EVA. A new component within the ventilation gas loop is a liquid-to-gas heat exchanger to transfer excess heat from the gas to the thermal control system s liquid coolant loop. A unique bench top prototype heat exchanger was built and tested for use in PLSS 2.0. The heat exchanger was designed as a counter-flow, compact plate fin type using stainless steel. Its design was based on previous compact heat exchangers manufactured by United Technologies Aerospace Systems (UTAS), but was half the size of any previous heat exchanger model and one third the size of previous liquid-to-gas heat exchangers. The prototype heat exchanger was less than 40 cubic inches and weighed 2.57 lb. Performance of the heat exchanger met the requirements and the model predictions. The water side and gas side pressure drops were less 0.8 psid and 0.5 inches of water, respectively, and an effectiveness of 94% was measured at the nominal air side pressure of 4.1 psia.

  15. Performance evaluation on an air-cooled heat exchanger for alumina nanofluid under laminar flow.

    PubMed

    Teng, Tun-Ping; Hung, Yi-Hsuan; Teng, Tun-Chien; Chen, Jyun-Hong

    2011-08-09

    This study analyzes the characteristics of alumina (Al2O3)/water nanofluid to determine the feasibility of its application in an air-cooled heat exchanger for heat dissipation for PEMFC or electronic chip cooling. The experimental sample was Al2O3/water nanofluid produced by the direct synthesis method at three different concentrations (0.5, 1.0, and 1.5 wt.%). The experiments in this study measured the thermal conductivity and viscosity of nanofluid with weight fractions and sample temperatures (20-60°C), and then used the nanofluid in an actual air-cooled heat exchanger to assess its heat exchange capacity and pressure drop under laminar flow. Experimental results show that the nanofluid has a higher heat exchange capacity than water, and a higher concentration of nanoparticles provides an even better ratio of the heat exchange. The maximum enhanced ratio of heat exchange and pressure drop for all the experimental parameters in this study was about 39% and 5.6%, respectively. In addition to nanoparticle concentration, the temperature and mass flow rates of the working fluid can affect the enhanced ratio of heat exchange and pressure drop of nanofluid. The cross-section aspect ratio of tube in the heat exchanger is another important factor to be taken into consideration.

  16. Performance evaluation on an air-cooled heat exchanger for alumina nanofluid under laminar flow

    PubMed Central

    2011-01-01

    This study analyzes the characteristics of alumina (Al2O3)/water nanofluid to determine the feasibility of its application in an air-cooled heat exchanger for heat dissipation for PEMFC or electronic chip cooling. The experimental sample was Al2O3/water nanofluid produced by the direct synthesis method at three different concentrations (0.5, 1.0, and 1.5 wt.%). The experiments in this study measured the thermal conductivity and viscosity of nanofluid with weight fractions and sample temperatures (20-60°C), and then used the nanofluid in an actual air-cooled heat exchanger to assess its heat exchange capacity and pressure drop under laminar flow. Experimental results show that the nanofluid has a higher heat exchange capacity than water, and a higher concentration of nanoparticles provides an even better ratio of the heat exchange. The maximum enhanced ratio of heat exchange and pressure drop for all the experimental parameters in this study was about 39% and 5.6%, respectively. In addition to nanoparticle concentration, the temperature and mass flow rates of the working fluid can affect the enhanced ratio of heat exchange and pressure drop of nanofluid. The cross-section aspect ratio of tube in the heat exchanger is another important factor to be taken into consideration. PMID:21827644

  17. The design and fabrication of a Stirling engine heat exchanger module with an integral heat pipe

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.

    1988-01-01

    The conceptual design of a free-piston Stirling Space Engine (SSE) intended for space power applications has been generated. The engine was designed to produce 25 kW of electric power with heat supplied by a nuclear reactor. A novel heat exchanger module was designed to reduce the number of critical joints in the heat exchanger assembly while also incorporating a heat pipe as the link between the engine and the heat source. Two inexpensive verification tests are proposed. The SSE heat exchanger module is described and the operating conditions for the module are outlined. The design process of the heat exchanger modules, including the sodium heat pipe, is briefly described. Similarities between the proposed SSE heat exchanger modules and the LeRC test modules for two test engines are presented. The benefits and weaknesses of using a sodium heat pipe to transport heat to a Stirling engine are discussed. Similarly, the problems encountered when using a true heat pipe, as opposed to a more simple reflux boiler, are described. The instruments incorporated into the modules and the test program are also outlined.

  18. Rapid microfluidic thermal cycler for nucleic acid amplification

    DOEpatents

    Beer, Neil Reginald; Vafai, Kambiz

    2015-10-27

    A system for thermal cycling a material to be thermal cycled including a microfluidic heat exchanger; a porous medium in the microfluidic heat exchanger; a microfluidic thermal cycling chamber containing the material to be thermal cycled, the microfluidic thermal cycling chamber operatively connected to the microfluidic heat exchanger; a working fluid at first temperature; a first system for transmitting the working fluid at first temperature to the microfluidic heat exchanger; a working fluid at a second temperature, a second system for transmitting the working fluid at second temperature to the microfluidic heat exchanger; a pump for flowing the working fluid at the first temperature from the first system to the microfluidic heat exchanger and through the porous medium; and flowing the working fluid at the second temperature from the second system to the heat exchanger and through the porous medium.

  19. Heat and moisture exchanger: importance of humidification in anaesthesia and ventilatory breathing system.

    PubMed

    Parmar, Vandana

    2008-08-01

    Adequate humidification is vital to maintain homeostasis of the airway. Heat and moisture exchangers conserve some of the exhaled water, heat and return them to inspired gases. Many heat and moisture exchangers also perfom bacterial/viral filtration and prevent inhalation of small particles. Heat and moisture exchangers are also called condenser humidifier, artificial nose, etc. Most of them are disposable devices with exchanging medium enclosed in a plastic housing. For adult and paediatric age group different dead space types are available. Heat and moisture exchangers are helpful during anaesthesia and ventilatory breathing system. To reduce the damage of the upper respiratory tract through cooling and dehydration inspiratory air can be heated and humidified, thus preventing the serious complications.

  20. Carbon Dioxide-Lubricant Two-Phase Flow Patterns in Small Horizontal Wetted Wall Channels: The Effects of Refrigerant/Lubricant Thermophysical Properties

    ERIC Educational Resources Information Center

    Seeton, Christopher John

    2009-01-01

    Microchannel heat exchangers are gaining popularity due to their ability to handle high pressures, reduce refrigerant charge, and reduce heat exchanger package size. These heat exchanger designs provide better heat exchange performance due to increased refrigerant side heat transfer coefficients and geometries that allow for a denser packing…

  1. Design and simulation of heat exchangers using Aspen HYSYS, and Aspen exchanger design and rating for paddy drying application

    NASA Astrophysics Data System (ADS)

    Janaun, J.; Kamin, N. H.; Wong, K. H.; Tham, H. J.; Kong, V. V.; Farajpourlar, M.

    2016-06-01

    Air heating unit is one of the most important parts in paddy drying to ensure the efficiency of a drying process. In addition, an optimized air heating unit does not only promise a good paddy quality, but also save more for the operating cost. This study determined the suitable and best specifications heating unit to heat air for paddy drying in the LAMB dryer. In this study, Aspen HYSYS v7.3 was used to obtain the minimum flow rate of hot water needed. The resulting data obtained from Aspen HYSYS v7.3 were used in Aspen Exchanger Design and Rating (EDR) to generate heat exchanger design and costs. The designs include shell and tubes and plate heat exchanger. The heat exchanger was designed in order to produce various drying temperatures of 40, 50, 60 and 70°C of air with different flow rate, 300, 2500 and 5000 LPM. The optimum condition for the heat exchanger were found to be plate heat exchanger with 0.6 mm plate thickness, 198.75 mm plate width, 554.8 mm plate length and 11 numbers of plates operating at 5000 LPM air flow rate.

  2. 14 CFR 23.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Exhaust heat exchangers. 23.1125 Section 23... § 23.1125 Exhaust heat exchangers. For reciprocating engine powered airplanes the following apply: (a) Each exhaust heat exchanger must be constructed and installed to withstand the vibration, inertia, and...

  3. 14 CFR 23.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Exhaust heat exchangers. 23.1125 Section 23... § 23.1125 Exhaust heat exchangers. For reciprocating engine powered airplanes the following apply: (a) Each exhaust heat exchanger must be constructed and installed to withstand the vibration, inertia, and...

  4. 14 CFR 23.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Exhaust heat exchangers. 23.1125 Section 23... § 23.1125 Exhaust heat exchangers. For reciprocating engine powered airplanes the following apply: (a) Each exhaust heat exchanger must be constructed and installed to withstand the vibration, inertia, and...

  5. 40 CFR 63.655 - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sourcewide basis. (vi) For each heat exchange system, identification of the heat exchange systems that are subject to the requirements of this subpart. For heat exchange systems at existing sources, the owner or... averaging provisions in § 63.652 of this subpart. (9) For heat exchange systems, Periodic Reports must...

  6. 40 CFR 63.655 - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... sourcewide basis. (vi) For each heat exchange system, identification of the heat exchange systems that are... averaging provisions in § 63.652 of this subpart. (9) For heat exchange systems, Periodic Reports must include the following information: (i) The number of heat exchange systems in HAP service. (ii) The number...

  7. 40 CFR 63.655 - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sourcewide basis. (vi) For each heat exchange system, identification of the heat exchange systems that are subject to the requirements of this subpart. For heat exchange systems at existing sources, the owner or... averaging provisions in § 63.652 of this subpart. (9) For heat exchange systems, Periodic Reports must...

  8. 40 CFR 63.655 - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sourcewide basis. (vi) For each heat exchange system, identification of the heat exchange systems that are... averaging provisions in § 63.652 of this subpart. (9) For heat exchange systems, Periodic Reports must include the following information: (i) The number of heat exchange systems in HAP service. (ii) The number...

  9. 40 CFR 63.1435 - Heat exchanger provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Heat exchanger provisions. 63.1435... Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production § 63.1435 Heat exchanger... for heat exchange systems, with the exceptions noted in paragraphs (b) through (e) of this section. (b...

  10. 14 CFR 23.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Exhaust heat exchangers. 23.1125 Section 23... § 23.1125 Exhaust heat exchangers. For reciprocating engine powered airplanes the following apply: (a) Each exhaust heat exchanger must be constructed and installed to withstand the vibration, inertia, and...

  11. 40 CFR 63.1435 - Heat exchanger provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Heat exchanger provisions. 63.1435... Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production § 63.1435 Heat exchanger... for heat exchange systems, with the exceptions noted in paragraphs (b) through (e) of this section. (b...

  12. 14 CFR 23.1125 - Exhaust heat exchangers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Exhaust heat exchangers. 23.1125 Section 23... § 23.1125 Exhaust heat exchangers. For reciprocating engine powered airplanes the following apply: (a) Each exhaust heat exchanger must be constructed and installed to withstand the vibration, inertia, and...

  13. Cryogenic Heat Exchanger with Turbulent Flows

    ERIC Educational Resources Information Center

    Amrit, Jay; Douay, Christelle; Dubois, Francis; Defresne, Gerard

    2012-01-01

    An evaporator-type cryogenic heat exchanger is designed and built for introducing fluid-solid heat exchange phenomena to undergraduates in a practical and efficient way. The heat exchanger functions at liquid nitrogen temperature and enables cooling of N[subscript 2] and He gases from room temperatures. We present first the experimental results of…

  14. Evaluating humidity recovery efficiency of currently available heat and moisture exchangers: a respiratory system model study.

    PubMed

    Lucato, Jeanette Janaina Jaber; Adams, Alexander Bernard; Souza, Rogério; Torquato, Jamili Anbar; Carvalho, Carlos Roberto Ribeiro; Marini, John J

    2009-01-01

    To evaluate and compare the efficiency of humidification in available heat and moisture exchanger models under conditions of varying tidal volume, respiratory rate, and flow rate. Inspired gases are routinely preconditioned by heat and moisture exchangers to provide a heat and water content similar to that provided normally by the nose and upper airways. The absolute humidity of air retrieved from and returned to the ventilated patient is an important measurable outcome of the heat and moisture exchangers' humidifying performance. Eight different heat and moisture exchangers were studied using a respiratory system analog. The system included a heated chamber (acrylic glass, maintained at 37 degrees C), a preserved swine lung, a hygrometer, circuitry and a ventilator. Humidity and temperature levels were measured using eight distinct interposed heat and moisture exchangers given different tidal volumes, respiratory frequencies and flow-rate conditions. Recovery of absolute humidity (%RAH) was calculated for each setting. Increasing tidal volumes led to a reduction in %RAH for all heat and moisture exchangers while no significant effect was demonstrated in the context of varying respiratory rate or inspiratory flow. Our data indicate that heat and moisture exchangers are more efficient when used with low tidal volume ventilation. The roles of flow and respiratory rate were of lesser importance, suggesting that their adjustment has a less significant effect on the performance of heat and moisture exchangers.

  15. Thermo-aerodynamic efficiency of non-circular ducts with vortex enhancement of heat exchange in different types of compact heat exchangers

    NASA Astrophysics Data System (ADS)

    Vasilev, V. Ya; Nikiforova, S. A.

    2018-03-01

    Experimental studies of thermo-aerodynamic characteristics of non-circular ducts with discrete turbulators on walls and interrupted channels have confirmed the rational enhancement of convective heat transfer, in which the growth of heat transfer outstrips or equals the growth of aerodynamic losses. Determining the regularities of rational (energy-saving) enhancement of heat transfer and the proposed method for comparing the characteristics of smooth-channel (without enhancement) heat exchangers with effective analogs provide new results, confirming the high efficiency of vortex enhancement of convective heat transfer in non-circular ducts of plate-finned heat exchange surfaces. This allows creating heat exchangers with much smaller mass and volume for operation in energy-saving modes.

  16. Active microchannel heat exchanger

    DOEpatents

    Tonkovich, Anna Lee Y [Pasco, WA; Roberts, Gary L [West Richland, WA; Call, Charles J [Pasco, WA; Wegeng, Robert S [Richland, WA; Wang, Yong [Richland, WA

    2001-01-01

    The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

  17. Thermal response test data of five quadratic cross section precast pile heat exchangers.

    PubMed

    Alberdi-Pagola, Maria

    2018-06-01

    This data article comprises records from five Thermal Response Tests (TRT) of quadratic cross section pile heat exchangers. Pile heat exchangers, typically referred to as energy piles, consist of traditional foundation piles with embedded heat exchanger pipes. The data presented in this article are related to the research article entitled "Comparing heat flow models for interpretation of precast quadratic pile heat exchanger thermal response tests" (Alberdi-Pagola et al., 2018) [1]. The TRT data consists of measured inlet and outlet temperatures, fluid flow and injected heat rate recorded every 10 min. The field dataset is made available to enable model verification studies.

  18. Fluid to fluid contact heat exchanger

    NASA Technical Reports Server (NTRS)

    Clark, W. E.

    1986-01-01

    Heat transfer and pressure drop test results for a fluid to fluid contact heat exchanger are reported. The heat exchanger, fabricated and tested to demonstrate one method of transferring heat between structures in space, had a total contact area of 0.18 sq m. It utilized contact surfaces which were flexible and conformed to the mating contact surfaces upon pressurization of the fluid circulating within the heat exchanger. During proof-of-concept performance tests, the heat exchanger was operated in a typical earth environment. It demonstrated a contact conductance of 3.8 kW/sq m C at contact pressures in the 15 to 70 kPa range.

  19. Integrated solar collector

    DOEpatents

    Tchernev, Dimiter I.

    1985-01-01

    A solar collector having a copper panel in a contiguous space relationship with a condenser-evaporator heat exchanger located under the panel, the panel having a honeycomb-like structure on its interior defining individual cells which are filled with zeolite loaded, in its adsorbed condition, with 18 to 20% by weight of water. The interior of the panel and heat exchanger are maintained at subatmospheric pressure of about 0.1 to 1 psia. The panel and heat exchanger are insulated on their lateral sides and bottoms and on the top of the heat exchange. The panel has a black coating on its top which is exposed to and absorbs solar energy. Surrounding the insulation (which supports the panel) is an extruded aluminum framework which supports a pair of spaced-apart glass panels above the solar panel. Water in conduits from a system for heating or cooling or both is connected to flow into an inlet and discharge from outlet of a finned coil received within the heat exchanger. The collector panel provides heat during the day through desorption and condensing of water vapor from the heated solar panel in the heat exchanger and cools at night by the re-adsorption of the water vapor from the heat exchanger which lowers the absolute pressure within the system and cools the heat exchange coils by evaporation.

  20. Three-phase flow? Consider helical-coil heat exchangers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haraburda, S.S.

    1995-07-01

    In recent years, chemical process plants are increasingly encountering processes that require heat exchange in three-phase fluids. A typical application, for example, is heating liquids containing solid catalyst particles and non-condensable gases. Heat exchangers designed for three-phase flow generally have tubes with large diameters (typically greater than two inches), because solids can build-up inside the tube and lead to plugging. At the same time, in order to keep heat-transfer coefficients high, the velocity of the process fluid within the tube should also be high. As a result, heat exchangers for three-phase flow may require less than five tubes -- eachmore » having a required linear length that could exceed several hundred feet. Given these limitations, it is obvious that a basic shell-and-tube heat exchanger is not the most practical solution for this purpose. An alternative for three-phase flow is a helical-coil heat exchanger. The helical-coil units offer a number of advantages, including perpendicular, counter-current flow and flexible overall dimensions for the exchanger itself. The paper presents equations for: calculating the tube-side heat-transfer coefficient; calculating the shell-side heat-transfer coefficient; calculating the heat-exchanger size; calculating the tube-side pressure drop; and calculating shell-side pressure-drop.« less

  1. Aerodynamics of heat exchangers for high-altitude aircraft

    NASA Technical Reports Server (NTRS)

    Drela, Mark

    1996-01-01

    Reduction of convective beat transfer with altitude dictates unusually large beat exchangers for piston- engined high-altitude aircraft The relatively large aircraft drag fraction associated with cooling at high altitudes makes the efficient design of the entire heat exchanger installation an essential part of the aircraft's aerodynamic design. The parameters that directly influence cooling drag are developed in the context of high-altitude flight Candidate wing airfoils that incorporate heat exchangers are examined. Such integrated wing-airfoil/heat-exchanger installations appear to be attractive alternatives to isolated heat.exchanger installations. Examples are drawn from integrated installations on existing or planned high-altitude aircraft.

  2. Development, Fabrication, and Testing of a Liquid/Liquid Microchannel Heat Exchanger for Constellation Spacecrafts

    NASA Technical Reports Server (NTRS)

    Hawkins-Reynolds, Ebony; Le, Hung; Stephan, Ryan

    2010-01-01

    Microchannel technology can be incorporated into heat exchanger designs to decrease the mass and volume of space hardware. The National Aeronautics and Space Administration at the Johnson Space Center (NASA JSC) partnered with Pacific Northwest National Laboratories (PNNL) to develop a liquid/liquid microchannel heat exchanger that has significant mass and volume savings without sacrificing thermal and pressure drop performance. PNNL designed the microchannel heat exchanger to the same performance design requirements of a conventional plate and fin liquid/liquid heat exchanger; 3 kW duty with inlet temperatures of 26 C and 4 C. Both heat exchangers were tested using the same test parameters on a test apparatus and performance data compared.

  3. Criteria for scaling heat exchangers to miniature size

    NASA Technical Reports Server (NTRS)

    Rudolfvonrohr, P. B.; Smith, J. L., Jr.

    1985-01-01

    The purpose of this work is to highlight the particular aspects of miniature heat exchangers performance and to determine an appropriate design approach. A thermodynamic analysis is performed to express the generated entropy as a function of material and geometric characteristics of the heat exchangers. This expression is then used to size miniature heat exchangers.

  4. Ventilatory changes during the use of heat and moisture exchangers in patients submitted to mechanical ventilation with support pressure and adjustments in ventilation parameters to compensate for these possible changes: a self-controlled intervention study in humans.

    PubMed

    Lucato, Jeanette Janaina Jaber; Cunha, Thiago Marraccini Nogueira da; Reis, Aline Mela Dos; Picanço, Patricia Salerno de Almeida; Barbosa, Renata Cléia Claudino; Liberali, Joyce; Righetti, Renato Fraga

    2017-01-01

    To evaluate the possible changes in tidal volume, minute volume and respiratory rate caused by the use of a heat and moisture exchanger in patients receiving pressure support mechanical ventilation and to quantify the variation in pressure support required to compensate for the effect caused by the heat and moisture exchanger. Patients under invasive mechanical ventilation in pressure support mode were evaluated using heated humidifiers and heat and moisture exchangers. If the volume found using the heat and moisture exchangers was lower than that found with the heated humidifier, an increase in pressure support was initiated during the use of the heat and moisture exchanger until a pressure support value was obtained that enabled the patient to generate a value close to the initial tidal volume obtained with the heated humidifier. The analysis was performed by means of the paired t test, and incremental values were expressed as percentages of increase required. A total of 26 patients were evaluated. The use of heat and moisture exchangers increased the respiratory rate and reduced the tidal and minute volumes compared with the use of the heated humidifier. Patients required a 38.13% increase in pressure support to maintain previous volumes when using the heat and moisture exchanger. The heat and moisture exchanger changed the tidal and minute volumes and respiratory rate parameters. Pressure support was increased to compensate for these changes.

  5. Ventilatory changes during the use of heat and moisture exchangers in patients submitted to mechanical ventilation with support pressure and adjustments in ventilation parameters to compensate for these possible changes: a self-controlled intervention study in humans

    PubMed Central

    Lucato, Jeanette Janaina Jaber; da Cunha, Thiago Marraccini Nogueira; dos Reis, Aline Mela; Picanço, Patricia Salerno de Almeida; Barbosa, Renata Cléia Claudino; Liberali, Joyce; Righetti, Renato Fraga

    2017-01-01

    Objective To evaluate the possible changes in tidal volume, minute volume and respiratory rate caused by the use of a heat and moisture exchanger in patients receiving pressure support mechanical ventilation and to quantify the variation in pressure support required to compensate for the effect caused by the heat and moisture exchanger. Methods Patients under invasive mechanical ventilation in pressure support mode were evaluated using heated humidifiers and heat and moisture exchangers. If the volume found using the heat and moisture exchangers was lower than that found with the heated humidifier, an increase in pressure support was initiated during the use of the heat and moisture exchanger until a pressure support value was obtained that enabled the patient to generate a value close to the initial tidal volume obtained with the heated humidifier. The analysis was performed by means of the paired t test, and incremental values were expressed as percentages of increase required. Results A total of 26 patients were evaluated. The use of heat and moisture exchangers increased the respiratory rate and reduced the tidal and minute volumes compared with the use of the heated humidifier. Patients required a 38.13% increase in pressure support to maintain previous volumes when using the heat and moisture exchanger. Conclusion The heat and moisture exchanger changed the tidal and minute volumes and respiratory rate parameters. Pressure support was increased to compensate for these changes. PMID:28977257

  6. New latent heat storage system with nanoparticles for thermal management of electric vehicles

    NASA Astrophysics Data System (ADS)

    Javani, N.; Dincer, I.; Naterer, G. F.

    2014-12-01

    In this paper, a new passive thermal management system for electric vehicles is developed. A latent heat thermal energy storage with nanoparticles is designed and optimized. A genetic algorithm method is employed to minimize the length of the heat exchanger tubes. The results show that even the optimum length of a shell and tube heat exchanger becomes too large to be employed in a vehicle. This is mainly due to the very low thermal conductivity of phase change material (PCM) which fills the shell side of the heat exchanger. A carbon nanotube (CNT) and PCM mixture is then studied where the probability of nanotubes in a series configuration is defined as a deterministic design parameter. Various heat transfer rates, ranging from 300 W to 600 W, are utilized to optimize battery cooling options in the heat exchanger. The optimization results show that smaller tube diameters minimize the heat exchanger length. Furthermore, finned tubes lead to a higher heat exchanger length due to more heat transfer resistance. By increasing the CNT concentration, the optimum length of the heat exchanger decreases and makes the improved thermal management system a more efficient and competitive with air and liquid thermal management systems.

  7. 14 CFR 27.859 - Heating systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) Heat exchangers. Each heat exchanger must be— (1) Of suitable materials; (2) Adequately cooled under... following occurs: (i) The heat exchanger temperature exceeds safe limits. (ii) The ventilating air..., the heat output of which is essential for safe operation; and (ii) Keep the heater off until restarted...

  8. 14 CFR 27.859 - Heating systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Heat exchangers. Each heat exchanger must be— (1) Of suitable materials; (2) Adequately cooled under... following occurs: (i) The heat exchanger temperature exceeds safe limits. (ii) The ventilating air..., the heat output of which is essential for safe operation; and (ii) Keep the heater off until restarted...

  9. 14 CFR 27.859 - Heating systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) Heat exchangers. Each heat exchanger must be— (1) Of suitable materials; (2) Adequately cooled under... following occurs: (i) The heat exchanger temperature exceeds safe limits. (ii) The ventilating air..., the heat output of which is essential for safe operation; and (ii) Keep the heater off until restarted...

  10. 14 CFR 27.859 - Heating systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) Heat exchangers. Each heat exchanger must be— (1) Of suitable materials; (2) Adequately cooled under... following occurs: (i) The heat exchanger temperature exceeds safe limits. (ii) The ventilating air..., the heat output of which is essential for safe operation; and (ii) Keep the heater off until restarted...

  11. Prototype Vent Gas Heat Exchanger for Exploration EVA - Performance and Manufacturing Characteristics

    NASA Technical Reports Server (NTRS)

    Jennings, Mallory; Quinn, Gregory; Strange, Jeremy

    2012-01-01

    NASA is developing new portable life support system (PLSS) technologies, which it is demonstrating in an unmanned ground based prototype unit called PLSS 2.0. One set of technologies within the PLSS provides suitable ventilation to an astronaut while on an EVA. A new component within the ventilation gas loop is a liquid-to-gas heat exchanger to transfer excess heat from the gas to the thermal control system's liquid coolant loop. A unique bench top prototype heat exchanger was built and tested for use in PLSS 2.0. The heat exchanger was designed as a counter-flow, compact plate fin type using stainless steel. Its design was based on previous compact heat exchangers manufactured by United Technologies Aerospace Systems, but was half the size of any previous heat exchanger model and one third the size of previous liquid-to-gas heat exchangers. The prototype heat exchanger was less than 40 cubic inches and weighed 2.6 lb. The water side and gas side pressure drops were 0.8 psid and 0.5 inches of water, respectively. Performance of the heat exchanger at the nominal pressure of 4.1 psia was measured at 94%, while a gas inlet pressure of 25 psia resulted in an effectiveness of 84%. These results compared well with the model, which was scaled for the small size. Modeling of certain phenomena that affect performance, such as flow distribution in the headers was particularly difficult due to the small size of the heat exchanger. Data from the tests has confirmed the correction factors that were used in these parts of the model.

  12. Heat exchanger for fuel cell power plant reformer

    DOEpatents

    Misage, Robert; Scheffler, Glenn W.; Setzer, Herbert J.; Margiott, Paul R.; Parenti, Jr., Edmund K.

    1988-01-01

    A heat exchanger uses the heat from processed fuel gas from a reformer for a fuel cell to superheat steam, to preheat raw fuel prior to entering the reformer and to heat a water-steam coolant mixture from the fuel cells. The processed fuel gas temperature is thus lowered to a level useful in the fuel cell reaction. The four temperature adjustments are accomplished in a single heat exchanger with only three heat transfer cores. The heat exchanger is preheated by circulating coolant and purge steam from the power section during startup of the latter.

  13. SHIPPING CONTAINER FOR RADIOACTIVE MATERIAL

    DOEpatents

    Nachbar, H.D.; Biggs, B.B.; Tariello, P.J.; George, K.O.

    1963-01-15

    A shipping container is described for transponting a large number of radioactive nuclear fuel element modules which produce a substantial amount of heat. The container comprises a primary pressure vessel and shield, and a rotatable head having an access port that can be indexed with module holders in the container. In order to remove heat generated in the fuel eleme nts, a heat exchanger is arranged within the container and in contact with a heat exchange fluid therein. The heat exchanger communicates with additional external heat exchangers, which dissipate heat to the atmosphere. (AEC)

  14. Process gas hear recovery

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Anderson, W.M.; Thurner, R.P.

    1977-01-01

    In considering the use of regenerative and recuperative heat exchangers for process-gas heat recovery general information regarding heat-exchanger effectiveness versus initial capital investment and operating costs is discussed. Specific examples for preheating combustion air for process furnaces and for using primary and secondary heat exchangers in conjunction with an air-pollution-control system for drying and curing ovens cover basic heat-exchanger design and application considerations as well as investment-payback factors.

  15. Direct fired heat exchanger

    DOEpatents

    Reimann, Robert C.; Root, Richard A.

    1986-01-01

    A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

  16. Improvement of heat transfer by means of ultrasound: Application to a double-tube heat exchanger.

    PubMed

    Legay, M; Simony, B; Boldo, P; Gondrexon, N; Le Person, S; Bontemps, A

    2012-11-01

    A new kind of ultrasonically-assisted heat exchanger has been designed, built and studied. It can be seen as a vibrating heat exchanger. A comprehensive description of the overall experimental set-up is provided, i.e. of the test rig and the acquisition system. Data acquisition and processing are explained step-by-step with a detailed example of graph obtained and how, from these experimental data, energy balance is calculated on the heat exchanger. It is demonstrated that ultrasound can be used efficiently as a heat transfer enhancement technique, even in such complex systems as heat exchangers. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Microtube strip heat exchanger

    NASA Astrophysics Data System (ADS)

    Doty, F. D.

    1991-07-01

    During the last quarter, Doty Scientific, Inc. (DSI) continued to make progress on the microtube strip (MTS) heat exchanger. The DSI completed a heat exchanger stress analysis of the ten-module heat exchanger bank; and performed a shell-side flow inhomogeneity analysis of the three-module heat exchanger bank. The company produced 50 tubestrips using an in-house CNC milling machine and began pressing them onto tube arrays. The DSI revised some of the tooling required to encapsulate a tube array and press tubestrips into the array to improve some of the prototype tooling.

  18. Functional design of heat exchange for pneumatic vehicles

    NASA Astrophysics Data System (ADS)

    Xu, Z. G.; Yang, D. Y.; Shen, W. D.; Liu, T. T.

    2017-10-01

    With the increasingly serious environmental problems, especially the impact of fog and haze, the development of air powered vehicles has become an important research direction of new energy vehicles. Quadrature test was done with different materials, i.e. stainless steel and aluminum alloy, at different inlet pressures, using different expansion gases, i.e. air, CO2, for heat exchanging properties for pneumatic vehicles. The mathematics as well as simulation methods are used to analyze the different heat exchanging effects in the multistage cylinder. The research results showed that the stainless steel has better effects in heat exchanging than Aluminum Alloy; the intake pressure has little effect on CO2 than the air in heat exchanging effect. CO2 is better in heat exchanging than air.

  19. Development and Application of Collaborative Optimization Software for Plate - fin Heat Exchanger

    NASA Astrophysics Data System (ADS)

    Chunzhen, Qiao; Ze, Zhang; Jiangfeng, Guo; Jian, Zhang

    2017-12-01

    This paper introduces the design ideas of the calculation software and application examples for plate - fin heat exchangers. Because of the large calculation quantity in the process of designing and optimizing heat exchangers, we used Visual Basic 6.0 as a software development carrier to design a basic calculation software to reduce the calculation quantity. Its design condition is plate - fin heat exchanger which was designed according to the boiler tail flue gas. The basis of the software is the traditional design method of the plate-fin heat exchanger. Using the software for design and calculation of plate-fin heat exchangers, discovery will effectively reduce the amount of computation, and similar to traditional methods, have a high value.

  20. An Experimentally Validated Numerical Modeling Technique for Perforated Plate Heat Exchangers

    PubMed Central

    Nellis, G. F.; Kelin, S. A.; Zhu, W.; Gianchandani, Y.

    2010-01-01

    Cryogenic and high-temperature systems often require compact heat exchangers with a high resistance to axial conduction in order to control the heat transfer induced by axial temperature differences. One attractive design for such applications is a perforated plate heat exchanger that utilizes high conductivity perforated plates to provide the stream-to-stream heat transfer and low conductivity spacers to prevent axial conduction between the perforated plates. This paper presents a numerical model of a perforated plate heat exchanger that accounts for axial conduction, external parasitic heat loads, variable fluid and material properties, and conduction to and from the ends of the heat exchanger. The numerical model is validated by experimentally testing several perforated plate heat exchangers that are fabricated using microelectromechanical systems based manufacturing methods. This type of heat exchanger was investigated for potential use in a cryosurgical probe. One of these heat exchangers included perforated plates with integrated platinum resistance thermometers. These plates provided in situ measurements of the internal temperature distribution in addition to the temperature, pressure, and flow rate measured at the inlet and exit ports of the device. The platinum wires were deposited between the fluid passages on the perforated plate and are used to measure the temperature at the interface between the wall material and the flowing fluid. The experimental testing demonstrates the ability of the numerical model to accurately predict both the overall performance and the internal temperature distribution of perforated plate heat exchangers over a range of geometry and operating conditions. The parameters that were varied include the axial length, temperature range, mass flow rate, and working fluid. PMID:20976021

  1. An Experimentally Validated Numerical Modeling Technique for Perforated Plate Heat Exchangers.

    PubMed

    White, M J; Nellis, G F; Kelin, S A; Zhu, W; Gianchandani, Y

    2010-11-01

    Cryogenic and high-temperature systems often require compact heat exchangers with a high resistance to axial conduction in order to control the heat transfer induced by axial temperature differences. One attractive design for such applications is a perforated plate heat exchanger that utilizes high conductivity perforated plates to provide the stream-to-stream heat transfer and low conductivity spacers to prevent axial conduction between the perforated plates. This paper presents a numerical model of a perforated plate heat exchanger that accounts for axial conduction, external parasitic heat loads, variable fluid and material properties, and conduction to and from the ends of the heat exchanger. The numerical model is validated by experimentally testing several perforated plate heat exchangers that are fabricated using microelectromechanical systems based manufacturing methods. This type of heat exchanger was investigated for potential use in a cryosurgical probe. One of these heat exchangers included perforated plates with integrated platinum resistance thermometers. These plates provided in situ measurements of the internal temperature distribution in addition to the temperature, pressure, and flow rate measured at the inlet and exit ports of the device. The platinum wires were deposited between the fluid passages on the perforated plate and are used to measure the temperature at the interface between the wall material and the flowing fluid. The experimental testing demonstrates the ability of the numerical model to accurately predict both the overall performance and the internal temperature distribution of perforated plate heat exchangers over a range of geometry and operating conditions. The parameters that were varied include the axial length, temperature range, mass flow rate, and working fluid.

  2. Axial flow heat exchanger devices and methods for heat transfer using axial flow devices

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koplow, Jeffrey P.

    Systems and methods described herein are directed to rotary heat exchangers configured to transfer heat to a heat transfer medium flowing in substantially axial direction within the heat exchangers. Exemplary heat exchangers include a heat conducting structure which is configured to be in thermal contact with a thermal load or a thermal sink, and a heat transfer structure rotatably coupled to the heat conducting structure to form a gap region between the heat conducting structure and the heat transfer structure, the heat transfer structure being configured to rotate during operation of the device. In example devices heat may be transferredmore » across the gap region from a heated axial flow of the heat transfer medium to a cool stationary heat conducting structure, or from a heated stationary conducting structure to a cool axial flow of the heat transfer medium.« less

  3. Heat exchanger selection and design analyses for metal hydride heat pump systems

    DOE PAGES

    Mazzucco, Andrea; Voskuilen, Tyler G.; Waters, Essene L.; ...

    2016-01-01

    This paper presents a design analysis for the development of highly efficient heat exchangers within stationary metal hydride heat pumps. The design constraints and selected performance criteria are applied to three representative heat exchangers. The proposed thermal model can be applied to select the most efficient heat exchanger design and provides outcomes generally valid in a pre-design stage. Heat transfer effectiveness is the principal performance parameter guiding the selection analysis, the results of which appear to be mildly (up to 13%) affected by the specific Nusselt correlation used. The thermo-physical properties of the heat transfer medium and geometrical parameters aremore » varied in the sensitivity analysis, suggesting that the length of independent tubes is the physical parameter that influences the performance of the heat exchangers the most. The practical operative regions for each heat exchanger are identified by finding the conditions over which the heat removal from the solid bed enables a complete and continuous hydriding reaction. The most efficient solution is a design example that achieves the target effectiveness of 95%.« less

  4. A Mass Computation Model for Lightweight Brayton Cycle Regenerator Heat Exchangers

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    2010-01-01

    Based on a theoretical analysis of convective heat transfer across large internal surface areas, this paper discusses the design implications for generating lightweight gas-gas heat exchanger designs by packaging such areas into compact three-dimensional shapes. Allowances are made for hot and cold inlet and outlet headers for assembly of completed regenerator (or recuperator) heat exchanger units into closed cycle gas turbine flow ducting. Surface area and resulting volume and mass requirements are computed for a range of heat exchanger effectiveness values and internal heat transfer coefficients. Benefit cost curves show the effect of increasing heat exchanger effectiveness on Brayton cycle thermodynamic efficiency on the plus side, while also illustrating the cost in heat exchanger required surface area, volume, and mass requirements as effectiveness is increased. The equations derived for counterflow and crossflow configurations show that as effectiveness values approach unity, or 100 percent, the required surface area, and hence heat exchanger volume and mass tend toward infinity, since the implication is that heat is transferred at a zero temperature difference. To verify the dimensional accuracy of the regenerator mass computational procedure, calculation of a regenerator specific mass, that is, heat exchanger weight per unit working fluid mass flow, is performed in both English and SI units. Identical numerical values for the specific mass parameter, whether expressed in lb/(lb/sec) or kg/(kg/sec), show the dimensional consistency of overall results.

  5. A Mass Computation Model for Lightweight Brayton Cycle Regenerator Heat Exchangers

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    2010-01-01

    Based on a theoretical analysis of convective heat transfer across large internal surface areas, this paper discusses the design implications for generating lightweight gas-gas heat exchanger designs by packaging such areas into compact three-dimensional shapes. Allowances are made for hot and cold inlet and outlet headers for assembly of completed regenerator (or recuperator) heat exchanger units into closed cycle gas turbine flow ducting. Surface area and resulting volume and mass requirements are computed for a range of heat exchanger effectiveness values and internal heat transfer coefficients. Benefit cost curves show the effect of increasing heat exchanger effectiveness on Brayton cycle thermodynamic efficiency on the plus side, while also illustrating the cost in heat exchanger required surface area, volume, and mass requirements as effectiveness is increased. The equations derived for counterflow and crossflow configurations show that as effectiveness values approach unity, or 100 percent, the required surface area, and hence heat exchanger volume and mass tend toward infinity, since the implication is that heat is transferred at a zero temperature difference. To verify the dimensional accuracy of the regenerator mass computational procedure, calculation of a regenerator specific mass, that is, heat exchanger weight per unit working fluid mass flow, is performed in both English and SI units. Identical numerical values for the specific mass parameter, whether expressed in lb/(lb/sec) or kg/ (kg/sec), show the dimensional consistency of overall results.

  6. Technology Solutions Case Study: Foundation Heat Exchanger, Oak Ridge, Tennessee

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2014-03-01

    The foundation heat exchanger, developed by Oak Ridge National Laboratory, is a new concept for a cost-effective horizontal ground heat exchanger that can be connected to water-to-water or water-to-air heat pump systems for space conditioning as well as domestic water heating.

  7. HEAT TRANSFER MEANS

    DOEpatents

    Fraas, A.P.; Wislicenus, G.F.

    1961-07-11

    A heat exchanger is adapted to unifomly cool a spherical surface. Equations for the design of a spherical heat exchanger hav~g tubes with a uniform center-to-center spining are given. The heat exchanger is illustrated in connection with a liquid-fueled reactor.

  8. Evaluation of a heat exchanger for use in the Integrated Equipment Test facility solvent-extraction system

    NASA Astrophysics Data System (ADS)

    Lewis, B. E.

    1982-12-01

    The primary decontamination extraction section product (HAP) heat exchanger will be located between the extracting section (HA) and scrubbing section (HS) of centrifugal solvent extraction contactors in the Integrated Equipment Test (IET) facility. The heat exchanger is required to raise the temperature of the organic product stream from the HA contactor from 40 to 500 C. Tests were conducted under prototypic IET operating conditions to determine the head requirements for gravity flow and the overall heat transfer coefficient for the heat exchanger. Results from the tests indicated that the specified heat exchanger would perform satisfactorily under normal operating conditions.

  9. Development of a contact heat exchanger for a constructable radiator system

    NASA Technical Reports Server (NTRS)

    Howell, H. R.

    1983-01-01

    A development program for a contact heat exchanger to be used to transfer heat from a spacecraft coolant loop to a heat pipe radiator is described. The contact heat exchanger provides for a connectable/disconnectable joint which allows for on-orbit assembly of the radiator system and replacement or exchange of radiator panels for repair and maintenance. The contact heat exchanger does not require the transfer of fluid across the joint; the spacecraft coolant loop remains contained in an all welded system with no static or dynamic fluid seals. The contact interface is also "dry' with no conductive grease or interstitial material required.

  10. Ceramic heat exchangers for gas turbines or turbojets

    NASA Astrophysics Data System (ADS)

    Boudigues, S.; Fabri, J.

    The required performance goals and several proposed designs for SiC heat exchangers for aerospace turbines are presented. Ceramic materials are explored as a means for achieving higher operating temperatures while controlling the weight and cost of the heat exchangers. Thermodynamic analyses and model tests by ONERA have demonstrated the efficacy of introducing a recooling cycle and placing the heat exchangers between stages of the turbine. Sample applications are discussed for small general aviation aircraft and subsonic missiles equipped with single-flux exchangers. A double-flux exchanger is considered for an aircraft capable of Mach 0.8 speed and at least 11 km altitude for cruise. Finally, the results of initial attempts to manufacture SiC honeycomb heat exchangers are detailed.

  11. Air/molten salt direct-contact heat-transfer experiment and economic analysis

    NASA Astrophysics Data System (ADS)

    Bohn, M. S.

    1983-11-01

    Direct-contact heat-transfer coefficients have been measured in a pilot-scale packed column heat exchanger for molten salt/air duty. Two types of commercial tower packings were tested: metal Raschig rings and initial Pall rings. Volumetric heat-transfer coefficients were measured and appeared to depend upon air flow but not on salt flow rate. An economic analysis was used to compare the cost-effectiveness of direct-contact heat exchange with finned-tube heat exchanger in this application. Incorporating the measured volumetric heat-transfer coefficients, a direct-contact system appeared to be from two to five times as cost-effective as a finned-tube heat exchanger, depending upon operating temperature. The large cost advantage occurs for higher operating temperatures (2700(0)C), where high rates of heat transfer and flexibility in materials choice give the cost advantage to the direct-contact heat exchanger.

  12. Influence of additional heat exchanger block on directional solidification system for growing multi-crystalline silicon ingot - A simulation investigation

    NASA Astrophysics Data System (ADS)

    Nagarajan, S. G.; Srinivasan, M.; Aravinth, K.; Ramasamy, P.

    2018-04-01

    Transient simulation has been carried out for analyzing the heat transfer properties of Directional Solidification (DS) furnace. The simulation results revealed that the additional heat exchanger block under the bottom insulation on the DS furnace has enhanced the control of solidification of the silicon melt. Controlled Heat extraction rate during the solidification of silicon melt is requisite for growing good quality ingots which has been achieved by the additional heat exchanger block. As an additional heat exchanger block, the water circulating plate has been placed under the bottom insulation. The heat flux analysis of DS system and the temperature distribution studies of grown ingot confirm that the established additional heat exchanger block on the DS system gives additional benefit to the mc-Si ingot.

  13. Comparative ex vivo study on humidifying function of three speaking valves with integrated heat and moisture exchanger for tracheotomised patients.

    PubMed

    van den Boer, C; Lansaat, L; Muller, S H; van den Brekel, M W M; Hilgers, F J M

    2015-12-01

    Assessment of humidifying function of tracheotomy speaking valves with integrated heat and moisture exchanger. Ex vivo measurement of water exchange and storage capacity of three tracheotomy speaking valves: Humidiphon Plus, Spiro and ProTrach DualCare (with two different heat and moisture exchangers: XtraMoist and Regular). Comprehensive Cancer Centre. Healthy volunteer. Difference between end-inspiratory and end-expiratory weight as measure for water exchange capacity, weight after 10 min breathing as measure for water storage capacity, weighing at 1-min intervals to assess residual water exchange potential in speaking mode and absolute humidity in mg/L as measure for environmental and respiratory humidity. None of the tracheotomy speaking valves provides humidification while in speaking mode. Only the ProTrach DualCare allows blocking the speaking valve and breathing through the heat and moisture exchanger during inhalation and exhalation (heat and moisture exchanger mode). This leads to an increase in inspiratory humidity of 2.5 mg (XtraMoist) and 1.6 mg (Regular). There was no measurable water storage in speaking mode in any of the three tracheotomy speaking valves. In breathing mode, water storage in the DualCare heat and moisture exchangers was 47 and 37 mg, respectively. The remaining humidifying potential in speaking mode after 10 min breathing in heat and moisture exchanger mode for XtraMoist was 38%, 15% and 10% at 1, 2 and 3 min, respectively. For Regular, this was 47%, 24% and 13%, respectively. Tracheostoma valves with integrated heat and moisture exchanger have no humidification function in speaking mode. Only ProTrach DualCare, allowing blocking the speaking mode, in heat and moisture exchanger mode enables a significant increase in humidification. Regular switching between speaking and heat and moisture exchanger mode with this latter device prolongs the humidification in speaking mode. © 2015 John Wiley & Sons Ltd.

  14. 46 CFR 54.15-15 - Relief devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., and heat exchangers (modifies UG-126). 54.15-15 Section 54.15-15 Shipping COAST GUARD, DEPARTMENT OF... devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126). (a) An approved... more than 6 percent above the safety valve setting. (f) A heat exchanger with liquid in the shell and...

  15. 46 CFR 54.15-15 - Relief devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., and heat exchangers (modifies UG-126). 54.15-15 Section 54.15-15 Shipping COAST GUARD, DEPARTMENT OF... devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126). (a) An approved... more than 6 percent above the safety valve setting. (f) A heat exchanger with liquid in the shell and...

  16. 46 CFR 54.15-15 - Relief devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., and heat exchangers (modifies UG-126). 54.15-15 Section 54.15-15 Shipping COAST GUARD, DEPARTMENT OF... devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126). (a) An approved... more than 6 percent above the safety valve setting. (f) A heat exchanger with liquid in the shell and...

  17. Heat exchanger support apparatus in a fluidized bed

    DOEpatents

    Lawton, Carl W.

    1982-01-01

    A heat exchanger is mounted in the upper portion of a fluidized combusting bed for the control of the temperature of the bed. A support, made up of tubes, is extended from the perforated plate of the fluidized bed up to the heat exchanger. The tubular support framework for the heat exchanger has liquid circulated therethrough to prevent deterioration of the support.

  18. 46 CFR 54.15-15 - Relief devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., and heat exchangers (modifies UG-126). 54.15-15 Section 54.15-15 Shipping COAST GUARD, DEPARTMENT OF... devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126). (a) An approved... more than 6 percent above the safety valve setting. (f) A heat exchanger with liquid in the shell and...

  19. 46 CFR 54.15-15 - Relief devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., and heat exchangers (modifies UG-126). 54.15-15 Section 54.15-15 Shipping COAST GUARD, DEPARTMENT OF... devices for unfired steam boilers, evaporators, and heat exchangers (modifies UG-126). (a) An approved... more than 6 percent above the safety valve setting. (f) A heat exchanger with liquid in the shell and...

  20. Fluidized bed combustor and coal gun-tube assembly therefor

    DOEpatents

    Hosek, William S.; Garruto, Edward J.

    1984-01-01

    A coal supply gun assembly for a fluidized bed combustor which includes heat exchange elements extending above the bed's distributor plate assembly and in which the gun's nozzles are disposed relative to the heat exchange elements to only discharge granular coal material between adjacent heat exchange elements and in a path which is substantially equidistant from adjacent heat exchange elements.

  1. How The Army Can Be An Environmental Paragon Through Energy

    DTIC Science & Technology

    2005-04-01

    with recycled energy efficient material . Installing solar heating and solar energy devices on all new buildings will allow water to be heated ...ground heat exchanger , heat pump, and ductwork to deliver the air. The heat exchanger consists of pipes (a loop) buried under the ground close to a...building. Water or water plus antifreeze flows through the heat exchanger pipes absorbing heat (in the winter) and giving up heat (in the summer

  2. Physical explosion analysis in heat exchanger network design

    NASA Astrophysics Data System (ADS)

    Pasha, M.; Zaini, D.; Shariff, A. M.

    2016-06-01

    The failure of shell and tube heat exchangers is being extensively experienced by the chemical process industries. This failure can create a loss of production for long time duration. Moreover, loss of containment through heat exchanger could potentially lead to a credible event such as fire, explosion and toxic release. There is a need to analyse the possible worst case effect originated from the loss of containment of the heat exchanger at the early design stage. Physical explosion analysis during the heat exchanger network design is presented in this work. Baker and Prugh explosion models are deployed for assessing the explosion effect. Microsoft Excel integrated with process design simulator through object linking and embedded (OLE) automation for this analysis. Aspen HYSYS V (8.0) used as a simulation platform in this work. A typical heat exchanger network of steam reforming and shift conversion process was presented as a case study. It is investigated from this analysis that overpressure generated from the physical explosion of each heat exchanger can be estimated in a more precise manner by using Prugh model. The present work could potentially assist the design engineer to identify the critical heat exchanger in the network at the preliminary design stage.

  3. Investigation and optimization of the depth of flue gas heat recovery in surface heat exchangers

    NASA Astrophysics Data System (ADS)

    Bespalov, V. V.; Bespalov, V. I.; Melnikov, D. V.

    2017-09-01

    Economic issues associated with designing deep flue gas heat recovery units for natural gas-fired boilers are examined. The governing parameter affecting the performance and cost of surface-type condensing heat recovery heat exchangers is the heat transfer surface area. When firing natural gas, the heat recovery depth depends on the flue gas temperature at the condenser outlet and determines the amount of condensed water vapor. The effect of the outlet flue gas temperature in a heat recovery heat exchanger on the additionally recovered heat power is studied. A correlation has been derived enabling one to determine the best heat recovery depth (or the final cooling temperature) maximizing the anticipated reduced annual profit of a power enterprise from implementation of energy-saving measures. Results of optimization are presented for a surface-type condensing gas-air plate heat recovery heat exchanger for the climatic conditions and the economic situation in Tomsk. The predictions demonstrate that it is economically feasible to design similar heat recovery heat exchangers for a flue gas outlet temperature of 10°C. In this case, the payback period for the investment in the heat recovery heat exchanger will be 1.5 years. The effect of various factors on the optimal outlet flue gas temperature was analyzed. Most climatic, economical, or technological factors have a minor effect on the best outlet temperature, which remains between 5 and 20°C when varying the affecting factors. The derived correlation enables us to preliminary estimate the outlet (final) flue gas temperature that should be used in designing the heat transfer surface of a heat recovery heat exchanger for a gas-fired boiler as applied to the specific climatic conditions.

  4. Advanced Heat/Mass Exchanger Technology for Geothermal and Solar Renewable Energy Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Greiner, Miles; Childress, Amy; Hiibel, Sage

    2014-12-16

    Northern Nevada has abundant geothermal and solar energy resources, and these renewable energy sources provide an ample opportunity to produce economically viable power. Heat/mass exchangers are essential components to any energy conversion system. Improvements in the heat/mass exchange process will lead to smaller, less costly (more efficient) systems. There is an emerging heat transfer technology, based on micro/nano/molecular-scale surface science that can be applied to heat/mass exchanger design. The objective is to develop and characterize unique coating materials, surface configurations and membranes capable of accommodating a 10-fold increase in heat/mass exchanger performance via phase change processes (boiling, condensation, etc.) andmore » single phase convective heat/mass transfer.« less

  5. Radial flow heat exchanger

    DOEpatents

    Valenzuela, Javier

    2001-01-01

    A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

  6. Evaluation of a Passive Heat Exchanger Based Cooling System for Fuel Cell Applications

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Burke, Kenneth A.

    2011-01-01

    Fuel cell cooling is conventionally performed with an actively controlled, dedicated coolant loop that exchanges heat with a separate external cooling loop. To simplify this system the concept of directly cooling a fuel cell utilizing a coolant loop with a regenerative heat exchanger to preheat the coolant entering the fuel cell with the coolant exiting the fuel cell was analyzed. The preheating is necessary to minimize the temperature difference across the fuel cell stack. This type of coolant system would minimize the controls needed on the coolant loop and provide a mostly passive means of cooling the fuel cell. The results indicate that an operating temperature of near or greater than 70 C is achievable with a heat exchanger effectiveness of around 90 percent. Of the heat exchanger types evaluated with the same type of fluid on the hot and cold side, a counter flow type heat exchanger would be required which has the possibility of achieving the required effectiveness. The number of heat transfer units required by the heat exchanger would be around 9 or greater. Although the analysis indicates the concept is feasible, the heat exchanger design would need to be developed and optimized for a specific fuel cell operation in order to achieve the high effectiveness value required.

  7. Numerical Study on Crossflow Printed Circuit Heat Exchanger for Advanced Small Modular Reactors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yoon, Su-Jong; Sabharwall, Piyush; Kim, Eung-Soo

    2014-03-01

    Various fluids such as water, gases (helium), molten salts (FLiNaK, FLiBe) and liquid metal (sodium) are used as a coolant of advanced small modular reactors (SMRs). The printed circuit heat exchanger (PCHE) has been adopted as the intermediate and/or secondary heat exchanger of SMR systems because this heat exchanger is compact and effective. The size and cost of PCHE can be changed by the coolant type of each SMR. In this study, the crossflow PCHE analysis code for advanced small modular reactor has been developed for the thermal design and cost estimation of the heat exchanger. The analytical solution ofmore » single pass, both unmixed fluids crossflow heat exchanger model was employed to calculate a two dimensional temperature profile of a crossflow PCHE. The analytical solution of crossflow heat exchanger was simply implemented by using built in function of the MATLAB program. The effect of fluid property uncertainty on the calculation results was evaluated. In addition, the effect of heat transfer correlations on the calculated temperature profile was analyzed by taking into account possible combinations of primary and secondary coolants in the SMR systems. Size and cost of heat exchanger were evaluated for the given temperature requirement of each SMR.« less

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bandhauer, Todd; Deri, Robert J.; Elmer, John W.

    A laser diode package includes a heat pipe having a fluid chamber enclosed in part by a heat exchange wall for containing a fluid. Wicking channels in the fluid chamber is adapted to wick a liquid phase of the fluid from a condensing section of the heat pipe to an evaporating section of the heat exchanger, and a laser diode is connected to the heat exchange wall at the evaporating section of the heat exchanger so that heat produced by the laser diode is removed isothermally from the evaporating section to the condensing section by a liquid-to-vapor phase change ofmore » the fluid.« less

  9. CABLE CONNECTOR

    DOEpatents

    Caller, J.M.

    1962-05-01

    An electrical connector is designed for utilization in connection with either round or flat coaxial cables. The connector comprises a bayonet-type coupling arrangement with a splined movable locking sleeve adapted to lock together components of the connector. A compression spring is attached to one of the connector components and functions to forcibly separate mating components when the locking sleeve is in an unlocked condition so as to minimize the possibility of leaving the conductors electrically coupled. (AEC)

  10. 40 CFR 63.11499 - What are the standards and compliance requirements for heat exchange systems?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements for heat exchange systems? 63.11499 Section 63.11499 Protection of Environment ENVIRONMENTAL... and compliance requirements for heat exchange systems? (a) If the cooling water flow rate in your heat... part 211, you may use the physical integrity of the reactor as the surrogate indicator of heat...

  11. 40 CFR 63.11499 - What are the standards and compliance requirements for heat exchange systems?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements for heat exchange systems? 63.11499 Section 63.11499 Protection of Environment ENVIRONMENTAL... and compliance requirements for heat exchange systems? (a) If the cooling water flow rate in your heat... part 211, you may use the physical integrity of the reactor as the surrogate indicator of heat...

  12. 40 CFR 63.11499 - What are the standards and compliance requirements for heat exchange systems?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements for heat exchange systems? 63.11499 Section 63.11499 Protection of Environment ENVIRONMENTAL... and compliance requirements for heat exchange systems? (a) If the cooling water flow rate in your heat... part 211, you may use the physical integrity of the reactor as the surrogate indicator of heat...

  13. 40 CFR 63.11499 - What are the standards and compliance requirements for heat exchange systems?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirements for heat exchange systems? 63.11499 Section 63.11499 Protection of Environment ENVIRONMENTAL... and compliance requirements for heat exchange systems? (a) If the cooling water flow rate in your heat... part 211, you may use the physical integrity of the reactor as the surrogate indicator of heat...

  14. 40 CFR 63.11499 - What are the standards and compliance requirements for heat exchange systems?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements for heat exchange systems? 63.11499 Section 63.11499 Protection of Environment ENVIRONMENTAL... and compliance requirements for heat exchange systems? (a) If the cooling water flow rate in your heat... part 211, you may use the physical integrity of the reactor as the surrogate indicator of heat...

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

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  16. Heat pipe array heat exchanger

    DOEpatents

    Reimann, Robert C.

    1987-08-25

    A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

  17. Testing of heat exchanger systems for reheating flue gases from wet scrubbing desulfurization plants

    NASA Astrophysics Data System (ADS)

    Than, K.

    1982-09-01

    Two heat exchanger systems: the cyclic process of GEA and, the plate heat exchanger of Kablitz/Thyssen, for reheating flue gases, which have been cooled to about 50 to 55 C due to wet scrubbing, to the required temperature at the outlet of the stack by extracting the sensible heat of the hot flue gases were tested. The problem of building materials and on keeping clean the heat exchanger surface are emphasized.

  18. Performance optimization of a miniature Joule-Thomson cryocooler using numerical model

    NASA Astrophysics Data System (ADS)

    Ardhapurkar, P. M.; Atrey, M. D.

    2014-09-01

    The performance of a miniature Joule-Thomson cryocooler depends on the effectiveness of the heat exchanger. The heat exchanger used in such cryocooler is Hampson-type recuperative heat exchanger. The design of the efficient heat exchanger is crucial for the optimum performance of the cryocooler. In the present work, the heat exchanger is numerically simulated for the steady state conditions and the results are validated against the experimental data available from the literature. The area correction factor is identified for the calculation of effective heat transfer area which takes into account the effect of helical geometry. In order to get an optimum performance of the cryocoolers, operating parameters like mass flow rate, pressure and design parameters like heat exchanger length, helical diameter of coil, fin dimensions, fin density have to be identified. The present work systematically addresses this aspect of design for miniature J-T cryocooler.

  19. Performance evaluation of cryogenic counter-flow heat exchangers with longitudinal conduction, heat in-leak and property variations

    NASA Astrophysics Data System (ADS)

    Jiang, Q. F.; Zhuang, M.; Zhu, Z. G.; Y Zhang, Q.; Sheng, L. H.

    2017-12-01

    Counter-flow plate-fin heat exchangers are commonly utilized in cryogenic applications due to their high effectiveness and compact size. For cryogenic heat exchangers in helium liquefaction/refrigeration systems, conventional design theory is no longer applicable and they are usually sensitive to longitudinal heat conduction, heat in-leak from surroundings and variable fluid properties. Governing equations based on distributed parameter method are developed to evaluate performance deterioration caused by these effects. The numerical model could also be applied in many other recuperators with different structures and, hence, available experimental data are used to validate it. For a specific case of the multi-stream heat exchanger in the EAST helium refrigerator, quantitative effects of these heat losses are further discussed, in comparison with design results obtained by the common commercial software. The numerical model could be useful to evaluate and rate the heat exchanger performance under the actual cryogenic environment.

  20. Evaluating Humidity Recovery Efficiency of Currently Available Heat and Moisture Exchangers: A Respiratory System Model Study

    PubMed Central

    Lucato, Jeanette Janaina Jaber; Adams, Alexander Bernard; Souza, Rogério; Torquato, Jamili Anbar; Carvalho, Carlos Roberto Ribeiro; Marini, John J

    2009-01-01

    OBJECTIVES: To evaluate and compare the efficiency of humidification in available heat and moisture exchanger models under conditions of varying tidal volume, respiratory rate, and flow rate. INTRODUCTION: Inspired gases are routinely preconditioned by heat and moisture exchangers to provide a heat and water content similar to that provided normally by the nose and upper airways. The absolute humidity of air retrieved from and returned to the ventilated patient is an important measurable outcome of the heat and moisture exchangers’ humidifying performance. METHODS: Eight different heat and moisture exchangers were studied using a respiratory system analog. The system included a heated chamber (acrylic glass, maintained at 37°C), a preserved swine lung, a hygrometer, circuitry and a ventilator. Humidity and temperature levels were measured using eight distinct interposed heat and moisture exchangers given different tidal volumes, respiratory frequencies and flow-rate conditions. Recovery of absolute humidity (%RAH) was calculated for each setting. RESULTS: Increasing tidal volumes led to a reduction in %RAH for all heat and moisture exchangers while no significant effect was demonstrated in the context of varying respiratory rate or inspiratory flow. CONCLUSIONS: Our data indicate that heat and moisture exchangers are more efficient when used with low tidal volume ventilation. The roles of flow and respiratory rate were of lesser importance, suggesting that their adjustment has a less significant effect on the performance of heat and moisture exchangers. PMID:19578664

  1. Heat Exchanger Cleaning in Support of Ocean Thermal Energy Conversion (OTEC) - Electronics Subsystems.

    DTIC Science & Technology

    1980-12-01

    exchangers . The performance of heat exchangers will therefore decide the ultimate success or failure of OTEC . BACKGROUND Hardware development in support...8217AD-AG9 216 NAVAL COASTAL SYSTEMS CENTER PANAMA CITY FL F/S 13/10 HEAT EXCHANGER CLEANING IN SUPPORT OF OCEAN THERMAL ENERGY CONV"-ETC(U) DEC 80 D F...block minI ber) Heat Exchangers Chlorination Cleaning Electronics Thermal Energy Conversion 2%AISTRACT (Centhmes en; rewwe ide it neseer end iftefb Op

  2. Laser Processed Heat Exchangers

    NASA Technical Reports Server (NTRS)

    Hansen, Scott

    2017-01-01

    The Laser Processed Heat Exchanger project will investigate the use of laser processed surfaces to reduce mass and volume in liquid/liquid heat exchangers as well as the replacement of the harmful and problematic coatings of the Condensing Heat Exchangers (CHX). For this project, two scale unit test articles will be designed, manufactured, and tested. These two units are a high efficiency liquid/liquid HX and a high reliability CHX.

  3. Recuperative supercritical carbon dioxide cycle

    DOEpatents

    Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

    2014-11-18

    A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

  4. A bi-directional two-phase/two-phase heat exchanger

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Ottenstein, Laura

    1993-01-01

    This paper describes the design and test of a heat exchanger that transfers heat from one two-phase thermal loop to another with very small drops in temperature and pressure. The heat exchanger condenses the vapor in one loop while evaporating the liquid in the other without mixing of the condensing and evaporating fluids. The heat exchanger is bidirectional in that it can transfer heat in reverse, condensing on the normally evaporating side and vice versa. It is fully compatible with capillary pumped loops and mechanically pumped loops. Test results verified that performance of the heat exchanger met the design requirements. It demonstrated a heat transfer rate of 6800 watts in the normal mode of operation and 1000 watts in the reverse mode with temperature drops of less than 5 C between two thermal loops.

  5. Experimental investigation of hydrodynamics and heat exchange in the ring channel with heat exchangers in the modes of single-phase convection and bubble boiling

    NASA Astrophysics Data System (ADS)

    Agishev, B. Y.; Boltenko, E. A.; Varava, A. N.; Dedov, A. V.; Zakharenkov, A. V.; Komov, A. T.; Smorchova, Y. V.

    2018-03-01

    The effectiveness of the heat exchange intensifier “rib-twisted wire” is considered in this paper. The main goal is to study the influence of the wire coiling step t on heat transfer and hydraulic resistance for different values Ḣ of the dimensionless height of the edge Ḣ, as well as some results on heat exchange during bubbly boiling in an annular channel. Show: • a brief description and an image of the heat exchange intensifier “rib-twisted wire” • generalized results of studies of heat exchange and hydraulic resistance in the annular channel in the single-phase convection with different geometric characteristics of the intensifier; • empirical correlations of the generalized experimental results that allow to calculating the coefficient of hydraulic resistance and heat transfer in the range of regime parameters in the single-phase convection that is being studied. • some results of experiments in bubbly boiling regimes and near-critical thermal loads.

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

    NASA Technical Reports Server (NTRS)

    Lefrois, R. T.; Mathur, A. K.

    1980-01-01

    Five tasks to select, design, fabricate, test and evaluate candidate active heat exchanger modules for future applications to solar and conventional utility power plants were discussed. Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion phase change materials (PCMs) in the temperature range of 250 to 350 C. Twenty-six heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were selected for small-scale experimentation: a coated tube and shell heat exchanger and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over 50 candidate inorganic salt mixtures. Based on a salt screening process, eight major component salts were selected initially for further evaluation. The most attractive major components in the temperature range of 250 to 350 C appeared to be NaNO3, NaNO2, and NaOH. Sketches of the two active heat exchange concepts selected for test are given.

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

    NASA Astrophysics Data System (ADS)

    Lefrois, R. T.; Mathur, A. K.

    1980-04-01

    Five tasks to select, design, fabricate, test and evaluate candidate active heat exchanger modules for future applications to solar and conventional utility power plants were discussed. Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion phase change materials (PCMs) in the temperature range of 250 to 350 C. Twenty-six heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were selected for small-scale experimentation: a coated tube and shell heat exchanger and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over 50 candidate inorganic salt mixtures. Based on a salt screening process, eight major component salts were selected initially for further evaluation. The most attractive major components in the temperature range of 250 to 350 C appeared to be NaNO3, NaNO2, and NaOH. Sketches of the two active heat exchange concepts selected for test are given.

  8. Phase Change Material Heat Exchanger Life Test

    NASA Technical Reports Server (NTRS)

    Lillibridge, Sean; Stephan, Ryan; Lee, Steve; He, Hung

    2008-01-01

    Low Lunar Orbit (LLO) poses unique thermal challenges for the orbiting space craft, particularly regarding the performance of the radiators. The emitted infrared (IR) heat flux from the lunar surface varies drastically from the light side to the dark side of the moon. Due to the extremely high incident IR flux, especially at low beta angles, a radiator is oftentimes unable to reject the vehicle heat load throughout the entire lunar orbit. One solution to this problem is to implement Phase Change Material (PCM) Heat Exchangers. PCM Heat Exchangers act as a "thermal capacitor," storing thermal energy when the radiator is unable to reject the required heat load. The stored energy is then removed from the PCM heat exchanger when the environment is more benign. Because they do not use an expendable resource, such as the feed water used by sublimators and evaporators, PCM Heat Exchangers are ideal for long duration Low Lunar Orbit missions. The Advanced Thermal Control project at JSC is completing a PCM heat exchanger life test to determine whether further technology development is warranted. The life test is being conducted on four nPentadecane, carbon filament heat exchangers. Fluid loop performance, repeatability, and measurement of performance degradation over 2500 melt-freeze cycles will be performed and reported in the current document.

  9. Heat and mass exchanger

    DOEpatents

    Lowenstein, Andrew; Sibilia, Marc J.; Miller, Jeffrey A.; Tonon, Thomas

    2007-09-18

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  10. Heat and mass exchanger

    DOEpatents

    Lowenstein, Andrew [Princeton, NJ; Sibilia, Marc J [Princeton, NJ; Miller, Jeffrey A [Hopewell, NJ; Tonon, Thomas [Princeton, NJ

    2011-06-28

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  11. Fuel delivery system including heat exchanger means

    NASA Technical Reports Server (NTRS)

    Coffinberry, G. A. (Inventor)

    1978-01-01

    A fuel delivery system is presented wherein first and second heat exchanger means are each adapted to provide the transfer of heat between the fuel and a second fluid such as lubricating oil associated with the gas turbine engine. Valve means are included which are operative in a first mode to provide for flow of the second fluid through both first and second heat exchange means and further operative in a second mode for bypassing the second fluid around the second heat exchanger means.

  12. Under-humidification and over-humidification during moderate induced hypothermia with usual devices.

    PubMed

    Lellouche, François; Qader, Siham; Taille, Solenne; Lyazidi, Aissam; Brochard, Laurent

    2006-07-01

    In mechanically ventilated patients with induced hypothermia, the efficacy of heat and moisture exchangers and heated humidifiers to adequately humidify the airway is poorly known. The aim of the study was to assess the efficacy of different humidification devices during moderate hypothermia. Prospective, cross-over randomized study. Medical Intensive Care Unit in a University Hospital. Nine adult patients hospitalized after cardiac arrest in whom moderate hypothermia was induced (33 degrees C for 24[Symbol: see text]h). Patients were ventilated at admission (period designated "normothermia") with a heat and moisture exchanger, and were randomly ventilated during hypothermia with a heat and moisture exchanger, a heated humidifier, and an active heat and moisture exchanger. Core temperature, inspired and expired gas absolute and relative humidity were measured. Each system demonstrated limitations in its ability to humidify gases in the specific situation of hypothermia. Performances of heat and moisture exchangers were closely correlated to core temperature (r (2)[Symbol: see text]=[Symbol: see text]0.84). During hypothermia, heat and moisture exchangers led to major under-humidification, with absolute humidity below 25[Symbol: see text]mgH(2)O/l. The active heat and moisture exchanger slightly improved humidification. Heated humidifiers were mostly adequate but led to over-humidification in some patients, with inspiratory absolute humidity higher than maximal water content at 33 degrees C with a positive balance between inspiratory and expiratory water content. These results suggest that in the case of moderate hypothermia, heat and moisture exchangers should be used cautiously and that heated humidifiers may lead to over-humidification with the currently recommended settings.

  13. High Thermal Conductivity Polymer Composites for Low Cost Heat Exchangers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2017-08-01

    This factsheet describes a project that identified and evaluated commercially available and state-of-the-art polymer-based material options for manufacturing industrial and commercial non-metallic heat exchangers. A heat exchanger concept was also developed and its performance evaluated with heat transfer modeling tools.

  14. 46 CFR 151.40-1 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... lower energy vapor or its condensate returned to the tank. (2) External heat exchange. A refrigeration... heat exchanger. Refrigeration is not accomplished by direct compression of the cargo. (c) Internal heat exchange. A refrigeration system in which a cooling fluid is passed through heat transfer coils immersed in...

  15. 46 CFR 151.40-1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... lower energy vapor or its condensate returned to the tank. (2) External heat exchange. A refrigeration... heat exchanger. Refrigeration is not accomplished by direct compression of the cargo. (c) Internal heat exchange. A refrigeration system in which a cooling fluid is passed through heat transfer coils immersed in...

  16. 46 CFR 151.40-1 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... lower energy vapor or its condensate returned to the tank. (2) External heat exchange. A refrigeration... heat exchanger. Refrigeration is not accomplished by direct compression of the cargo. (c) Internal heat exchange. A refrigeration system in which a cooling fluid is passed through heat transfer coils immersed in...

  17. 46 CFR 151.40-1 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... lower energy vapor or its condensate returned to the tank. (2) External heat exchange. A refrigeration... heat exchanger. Refrigeration is not accomplished by direct compression of the cargo. (c) Internal heat exchange. A refrigeration system in which a cooling fluid is passed through heat transfer coils immersed in...

  18. 46 CFR 151.40-1 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... lower energy vapor or its condensate returned to the tank. (2) External heat exchange. A refrigeration... heat exchanger. Refrigeration is not accomplished by direct compression of the cargo. (c) Internal heat exchange. A refrigeration system in which a cooling fluid is passed through heat transfer coils immersed in...

  19. Circulating heat exchangers for oscillating wave engines and refrigerators

    DOEpatents

    Swift, Gregory W.; Backhaus, Scott N.

    2003-10-28

    An oscillating-wave engine or refrigerator having a regenerator or a stack in which oscillating flow of a working gas occurs in a direction defined by an axis of a trunk of the engine or refrigerator, incorporates an improved heat exchanger. First and second connections branch from the trunk at locations along the axis in selected proximity to one end of the regenerator or stack, where the trunk extends in two directions from the locations of the connections. A circulating heat exchanger loop is connected to the first and second connections. At least one fluidic diode within the circulating heat exchanger loop produces a superimposed steady flow component and oscillating flow component of the working gas within the circulating heat exchanger loop. A local process fluid is in thermal contact with an outside portion of the circulating heat exchanger loop.

  20. Fault Diagnosis for the Heat Exchanger of the Aircraft Environmental Control System Based on the Strong Tracking Filter

    PubMed Central

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system’s efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger. PMID:25823010

  1. Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

    PubMed

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

  2. Microtube strip heat exchanger

    NASA Astrophysics Data System (ADS)

    Doty, F. D.

    1990-12-01

    Doty Scientific (DSI) believes their microtube-strip heat exchanger will contribute significantly to the following: (1) the closed Brayton cycles being pursued at MIT, NASA, and elsewhere; (2) reverse Brayton cycle cryocoolers, currently being investigated by NASA for space missions, being applied to MRI superconducting magnets; and (3) high-efficiency cryogenic gas separation schemes for CO2 removal from exhaust stacks. The goal of this current study is to show the potential for substantial progress in high-effectiveness, low-cost, gas-to-gas heat exchangers for diverse applications at temperatures from below 100 K to above 1000 K. To date, the highest effectiveness measured is about 98 percent and relative pressure drops below 0.1 percent with a specific conductance of about 45 W/kgK are reported. During the pre-award period DSI built and tested a 3-module heat exchanger bank using 103-tube microtube strip (MTS) modules. To add to their analytical capabilities, DSI has acquired computational fluid dynamics (CFD) software. This report describes the pre-award work and the status of the ten tasks of the current project, which are: analyze flow distribution and thermal stresses within individual modules; design a heat exchanger bank of ten modules with 400 microtube per module; obtain production quality tubestrip die and AISI 304 tubestrips; obtain production quality microtubing; construct revised MTS heat exchanger; construct dies and fixtures for prototype heat exchanger; construct 100 MTS modules; assemble 8 to 10 prototype MTS heat exchangers; test prototype MTS heat exchanger; and verify test through independent means.

  3. Heat Transfer in Metal Foam Heat Exchangers at High Temperature

    NASA Astrophysics Data System (ADS)

    Hafeez, Pakeeza

    Heat transfer though open-cell metal foam is experimentally studied for heat exchanger and heat shield applications at high temperatures (˜750°C). Nickel foam sheets with pore densities of 10 and 40 pores per linear inch (PPI), have been used to make the heat exchangers and heat shields by using thermal spray coating to deposit an Inconel skin on a foam core. Heat transfer measurements were performed on a test rig capable of generating hot gas up to 1000°C. The heat exchangers were tested by exposing their outer surface to combustion gases at a temperature of 550°C and 750°C while being cooled by air flowing through them at room temperature at velocities up to 5 m/s. The temperature rise of the air, the surface temperature of the heat exchangers and the air temperature inside the heat exchanger were measured. The volumetric heat transfer coefficient and Nusselt number were calculated for different velocities. The heat transfer performance of the 40PPI sample brazed with the foil is found to be the most efficient. Pressure drop measurements were also performed for 10 and 40PPI metal foam. Thermographic measurements were done on 40PPI foam heat exchangers using a high temperature infrared camera. A high power electric heater was used to produce hot air at 300°C that passed over the foam heat exchanger while the cooling air was blown through it. Heat shields were made by depositing porous skins on metal foam and it was observed that a small amount of coolant leaking through the pores notably reduces the heat transfer from the hot gases. An analytical model was developed based assuming local thermal non-equilibrium that accounts for the temperature difference between solid and fluid phase. The experimental results are found to be in good agreement with the predicted values of the model.

  4. Thermally integrated staged methanol reformer and method

    DOEpatents

    Skala, Glenn William; Hart-Predmore, David James; Pettit, William Henry; Borup, Rodney Lynn

    2001-01-01

    A thermally integrated two-stage methanol reformer including a heat exchanger and first and second reactors colocated in a common housing in which a gaseous heat transfer medium circulates to carry heat from the heat exchanger into the reactors. The heat transfer medium comprises principally hydrogen, carbon dioxide, methanol vapor and water vapor formed in a first stage reforming reaction. A small portion of the circulating heat transfer medium is drawn off and reacted in a second stage reforming reaction which substantially completes the reaction of the methanol and water remaining in the drawn-off portion. Preferably, a PrOx reactor will be included in the housing upstream of the heat exchanger to supplement the heat provided by the heat exchanger.

  5. Multileg Heat-Pipe Evaporator

    NASA Technical Reports Server (NTRS)

    Alario, J. P.; Haslett, R. A.

    1986-01-01

    Parallel pipes provide high heat flow from small heat exchanger. Six parallel heat pipes extract heat from overlying heat exchanger, forming evaporator. Vapor channel in pipe contains wick that extends into screen tube in liquid channel. Rods in each channel hold wick and screen tube in place. Evaporator compact rather than extended and more compatible with existing heat-exchanger geometries. Prototype six-pipe evaporator only 0.3 m wide and 0.71 m long. With ammonia as working fluid, transports heat to finned condenser at rate of 1,200 W.

  6. Wound tube heat exchanger

    DOEpatents

    Ecker, Amir L.

    1983-01-01

    What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

  7. MULTI-SCALE MODELING AND APPROXIMATION ASSISTED OPTIMIZATION OF BARE TUBE HEAT EXCHANGERS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bacellar, Daniel; Ling, Jiazhen; Aute, Vikrant

    2014-01-01

    Air-to-refrigerant heat exchangers are very common in air-conditioning, heat pump and refrigeration applications. In these heat exchangers, there is a great benefit in terms of size, weight, refrigerant charge and heat transfer coefficient, by moving from conventional channel sizes (~ 9mm) to smaller channel sizes (< 5mm). This work investigates new designs for air-to-refrigerant heat exchangers with tube outer diameter ranging from 0.5 to 2.0mm. The goal of this research is to develop and optimize the design of these heat exchangers and compare their performance with existing state of the art designs. The air-side performance of various tube bundle configurationsmore » are analyzed using a Parallel Parameterized CFD (PPCFD) technique. PPCFD allows for fast-parametric CFD analyses of various geometries with topology change. Approximation techniques drastically reduce the number of CFD evaluations required during optimization. Maximum Entropy Design method is used for sampling and Kriging method is used for metamodeling. Metamodels are developed for the air-side heat transfer coefficients and pressure drop as a function of tube-bundle dimensions and air velocity. The metamodels are then integrated with an air-to-refrigerant heat exchanger design code. This integration allows a multi-scale analysis of air-side performance heat exchangers including air-to-refrigerant heat transfer and phase change. Overall optimization is carried out using a multi-objective genetic algorithm. The optimal designs found can exhibit 50 percent size reduction, 75 percent decrease in air side pressure drop and doubled air heat transfer coefficients compared to a high performance compact micro channel heat exchanger with same capacity and flow rates.« less

  8. The Shock and Vibration Digest. Volume 14, Number 7

    DTIC Science & Technology

    1982-07-01

    Yang, ed., pp 93-107, 13 figs, 4 refs Key Words: Tube arrays. Heat exchangers . Wind tunnel testing . Critical speeds. Fluid-induced excitation...the Eighties," Proc. Const. Indus. Res. Inform. Assoc. Conf., Lon- don, UK (Nov 1980). 38 BOOK REVIEWS FLOW-INDUCED HEAT EXCHANGER TUBE...1980 Heat exchanger problems caused by flow-induced vibration are of concern to designers and operators of heat exchangers . Flow-induced vibration

  9. Thermal/Fluid Analysis of a Composite Heat Exchanger for Use on the RLV Rocket Engine

    NASA Technical Reports Server (NTRS)

    Nguyen, Dalton

    2002-01-01

    As part of efforts to design a regeneratively cooled composite nozzle ramp for use on the reusable vehicle (RLV) rocket engine, an C-SiC composites heat exchanger concept was proposed for thermal performance evaluation. To test the feasibility of the concept, sample heat exchanger panels were made to fit the Glenn Research Center's cell 22 for testing. Operation of the heat exchanger was demonstrated in a combustion environment with high heat fluxes similar to the RLV Aerospike Ramp. Test measurements were reviewed and found to be valuable for the on going fluid and thermal analysis of the actual RLV composite ramp. Since the cooling fluid for the heat exchanger is water while the RLV Ramp cooling fluid is LH2, fluid and thermal models were constructed to correlate to the specific test set-up. The knowledge gained from this work will be helpful for analyzing the thermal response of the actual RLV Composite Ramp. The coolant thermal properties for the models are taken from test data. The heat exchanger's cooling performance was analyzed using the Generalized Fluid System Simulation Program (GFSSP). Temperatures of the heat exchanger's structure were predicted in finite element models using Patran and Sinda. Results from the analytical models and the tests show that RSC's heat exchanger satisfied the combustion environments in a series of 16 tests.

  10. Thermal/Fluid Analysis of a Composite Heat Exchanger for Use on the RLV Rocket Engine

    NASA Technical Reports Server (NTRS)

    Nguyen, Dalton; Turner, Larry D. (Technical Monitor)

    2001-01-01

    As part of efforts to design a regeneratively cooled composite nozzle ramp for use on the reusable vehicle (RLV) rocket engine, a C-SiC composite heat exchanger concept was proposed for thermal performance evaluation. To test the feasibility of the concept, sample heat exchanger panels were made to fit the Glenn Research Center's cell 22 for testing. Operation of the heat exchanger was demonstrated in a combustion environment with high heat fluxes similar to the RLV Aerospike Ramp. Test measurements were reviewed and found to be valuable for the on-going fluid and thermal analysis of the actual RLV composite ramp. Since the cooling fluid for the heat exchanger is water while the RLV Ramp cooling fluid is LH2, fluid and therma models were constructed to correlate to the specific test set-up. The knowledge gained from this work will be helpful for analyzing the thermal response of the actual RLV Composite Ramp. The coolant thermal properties for the models are taken from test data. The heat exchanger's cooling performance was analyzed using the Generalized Fluid System Simulation Program (GFSSP). Temperatures of the heat exchanger's structure were predicted in finite element models using Patran and Sinda. Results from the analytical models and the tests show that RSC's heat exchanger satisfied the combustion environments in a series of 16 tests.

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

    NASA Astrophysics Data System (ADS)

    Chichindaev, A. V.

    2017-11-01

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

  12. Integrated Heat Exchange For Recuperation In Gas Turbine Engines

    DTIC Science & Technology

    2016-12-01

    exchange system within the engine using existing blade surfaces to extract and insert heat. Due to the highly turbulent and transient flow, heat...transfer coefficients in turbomachinery are extremely high, making this possible. Heat transfer between the turbine and compressor blade surfaces could be...exchange system within the engine using existing blade surfaces to extract and insert heat. Due to the highly turbulent and transient flow, heat transfer

  13. Heat exchangers in regenerative gas turbine cycles

    NASA Astrophysics Data System (ADS)

    Nina, M. N. R.; Aguas, M. P. N.

    1985-09-01

    Advances in compact heat exchanger design and fabrication together with fuel cost rises continuously improve the attractability of regenerative gas turbine helicopter engines. In this study cycle parameters aiming at reduced specific fuel consumption and increased payload or mission range, have been optimized together with heat exchanger type and size. The discussion is based on a typical mission for an attack helicopter in the 900 kw power class. A range of heat exchangers is studied to define the most favorable geometry in terms of lower fuel consumption and minimum engine plus fuel weight. Heat exchanger volume, frontal area ratio and pressure drop effect on cycle efficiency are considered.

  14. Multi-Purpose Logistics Module (MPLM) Cargo Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Zampiceni, John J.; Harper, Lon T.

    2002-01-01

    This paper describes the New Shuttle Orbiter's Multi- Purpose Logistics Modulo (MPLM) Cargo Heat Exchanger (HX) and associated MPLM cooling system. This paper presents Heat Exchanger (HX) design and performance characteristics of the system.

  15. Liquid cooled plate heat exchanger for battery cooling of an electric vehicle (EV)

    NASA Astrophysics Data System (ADS)

    Rahman, M. M.; Rahman, H. Y.; Mahlia, T. M. I.; Sheng, J. L. Y.

    2016-03-01

    A liquid cooled plate heat exchanger was designed to improve the battery life of an electric vehicle which suffers from premature aging or degradation due to the heat generation during discharging and charging period. Computational fluid dynamics (CFD) was used as a tool to analyse the temperature distribution when a constant surface heat flux was set at the bottom surface of the battery. Several initial and boundary conditions were set based on the past studies on the plate heat exchanger in the simulation software. The design of the plate heat exchanger was based on the Nissan Leaf battery pack to analyse the temperature patterns. Water at different mass flow rates was used as heat transfer fluid. The analysis revealed the designed plate heat exchanger could maintain the surface temperature within the range of 20 to 40°C which is within the safe operating temperature of the battery.

  16. Heat exchangers for cardioplegia systems: in vitro study of four different concepts.

    PubMed

    Drummond, Mário; Novello, Waldyr Parorali; de Arruda, Antonio Celso Fonseca; Braile, Domingo Marcolino

    2003-05-01

    The aim of this work is the evaluation of four different heat exchangers used for myocardium during cardioplegic system in cardiac surgeries. Four types of shell and tube heat exchangers made of different exchange elements were constructed, as follows: stainless steel tubes, aluminium tubes, polypropylene hollow fiber, and bellows type. The evaluation was performed by in vitro tests of parameters such as heat transfer, pressure drop, and hemolysis tendency. The result has shown that all four systems tested were able to achieve the heat performance, and to offer low resistance to flow, and safety, as well as have low tendency to hemolysis. However, we can emphasize that the bellows type heat exchanger has a significant difference with regard to the other three types.

  17. Heat Recovery Ventilation for Housing: Air-to-Air Heat Exchangers.

    ERIC Educational Resources Information Center

    Corbett, Robert J.; Miller, Barbara

    The air-to-air heat exchanger (a fan powered ventilation device that recovers heat from stale outgoing air) is explained in this six-part publication. Topic areas addressed are: (1) the nature of air-to-air heat exchangers and how they work; (2) choosing and sizing the system; (3) installation, control, and maintenance of the system; (4) heat…

  18. Slotting Fins of Heat Exchangers to Provide Thermal Breaks

    NASA Technical Reports Server (NTRS)

    Scull, Timothy D.

    2003-01-01

    Heat exchangers that include slotted fins (in contradistinction to continuous fins) have been invented. The slotting of the fins provides thermal breaks that reduce thermal conduction along flow paths (longitudinal thermal conduction), which reduces heat-transfer efficiency. By increasing the ratio between transverse thermal conduction (the desired heat-transfer conduction) and longitudinal thermal conduction, slotting of the fins can be exploited to (1) increase heat-transfer efficiency (thereby reducing operating cost) for a given heat-exchanger length or to (2) reduce the length (thereby reducing the weight and/or cost) of the heat exchanger needed to obtain a given heat transfer efficiency. By reducing the length of a heat exchanger, one can reduce the pressure drop associated with the flow through it. In a case in which slotting enables the use of fins with thermal conductivity greater than could otherwise be tolerated on the basis of longitudinal thermal conduction, one can exploit the conductivity to make the fins longer (in the transverse direction) than they otherwise could be, thereby making it possible to make a heat exchanger that contains fewer channels and therefore, that weighs less, contains fewer potential leak paths, and can be constructed from fewer parts and, hence, reduced cost.

  19. Low Cost Polymer heat Exchangers for Condensing Boilers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Butcher, Thomas; Trojanowski, Rebecca; Wei, George

    2015-09-30

    Work in this project sought to develop a suitable design for a low cost, corrosion resistant heat exchanger as part of a high efficiency condensing boiler. Based upon the design parameters and cost analysis several geometries and material options were explored. The project also quantified and demonstrated the durability of the selected polymer/filler composite under expected operating conditions. The core material idea included a polymer matrix with fillers for thermal conductivity improvement. While the work focused on conventional heating oil, this concept could also be applicable to natural gas, low sulfur heating oil, and biodiesel- although these are considered tomore » be less challenging environments. An extruded polymer composite heat exchanger was designed, built, and tested during this project, demonstrating technical feasibility of this corrosion-resistant material approach. In such flue gas-to-air heat exchangers, the controlling resistance to heat transfer is in the gas-side convective layer and not in the tube material. For this reason, the lower thermal conductivity polymer composite heat exchanger can achieve overall heat transfer performance comparable to a metal heat exchanger. However, with the polymer composite, the surface temperature on the gas side will be higher, leading to a lower water vapor condensation rate.« less

  20. Recent trends in the development of heat exchangers for geothermal systems

    NASA Astrophysics Data System (ADS)

    Franco, A.; Vaccaro, M.

    2017-11-01

    The potential use of geothermal resources has been a remarkable driver for market players and companies operating in the field of geothermal energy conversion. For this reason, medium to low temperature geothermal resources have been the object of recent rise in consideration, with strong reference to the perspectives of development of Organic Rankine Cycle (ORC) technology. The main components of geothermal plants based on ORC cycle are surely the heat exchangers. A lot of different heat exchangers are required for the operation of ORC plants. Among those it is surely of major importance the Recovery Heat Exchanger (RHE, typically an evaporator), in which the operating fluid is evaporated. Also the Recuperator, in regenerative Organic Rankine Cycle, is of major interest in technology. Another important application of the heat exchangers is connected to the condensation, according to the possibility of liquid or air cooling media availability. The paper analyzes the importance of heat exchangers sizing and the connection with the operation of ORC power plants putting in evidence the real element of innovation: the consideration of the heat exchangers as central element for the optimum design of ORC systems.

  1. Fin-and-tube heat exchanger material and inlet velocity effect under frosting conditions

    NASA Astrophysics Data System (ADS)

    Keryakos, Elie; Toubassy, Joseph; Danlos, Amélie; Clodic, Denis; Descombes, Georges

    2017-02-01

    The frosting fin-and-tube heat exchanger used in this study is implemented in the dehydration process of a biogas upgrading pilot. Water is separated from the biogas by frosting it at very low temperatures on the cold surfaces of the fin-and-tube heat exchanger. Once frosted, a defrosting system is used to remove water from the process. The main interest of this study is the frosting system. The effects of the biogas velocity, fin material, tube material and frost layer thickness on the performance of the fin-and-tube heat exchanger are investigated. Increasing the biogas velocity tends to increase the frosting layer thickness and the external pressure drop. This will lead to decrease the heat exchanger performance and the frosting cycle duration. The thermal conductivity of the fins and tubes has a major effect on the performance of the heat exchanger. Higher thermal conductivity decreases the heat exchanged surface. A numerical model has been developed, then numerical and experimental results extracted from a biogas upgrading pilot are compared.

  2. Further Studies in Filmwise Condensation of Steam on Horizontal Finned Tubes

    DTIC Science & Technology

    1992-03-01

    which to base their design of Ocean Thermal Energy Conversion ( OTEC ) heat exchangers . ANL used two shell-and-tube heat exchangers , with no inserts, for...throughout the duration of this study. xiii~q I. INTRODUCTON A. BACKGROUND A reduction in size and weight of all types of heat exchangers aboard Naval...vessels will allow more efficient use of space. The benefits might include greater equipment accessibility for maintenance or greater heat exchanger

  3. The Effects of the Heat and Moisture Exchanger on Humidity, Airway Temperature, and Core Body Temperature

    DTIC Science & Technology

    1999-10-01

    was added to the experimental group. Three more measurements were recorded at 10, 30 and 60 minutes after the insertion of the heat and moisture...heat and moisture exchanger provided adequate humidification of the inspired gases. In the experimental group, there was no difference in...exchanger incorporated in the ventilator Heat and Moisture Exchangers 16 circuit (the experimental group) and 10 did not (the control group

  4. The heat exchanger of small pellet boiler for phytomass

    NASA Astrophysics Data System (ADS)

    Mičieta, Jozef; Lenhard, Richard; Jandačka, Jozef

    2014-08-01

    Combustion of pellets from plant biomass (phytomass) causes various troubles. Main problem is slagging ash because of low melting temperature of ash from phytomass. This problem is possible to solve either improving energetic properties of phytomass by additives or modification of boiler construction. A small-scale boiler for phytomass is different in construction of heat exchanger and furnace mainly. We solve major problem - slagging ash, by decreasing combustion temperature via redesign of pellet burner and boiler body. Consequence of lower combustion temperature is also lower temperature gradient of combustion gas. It means that is necessary to design larger heat exchanging surface. We plane to use underfed burner, so we would utilize circle symmetry heat exchanger. Paper deals design of heat exchanger construction with help of CFD simulation. Our purpose is to keep uniform water flux and combustion gas flux in heat exchanger without zone of local overheating and excess cooling.

  5. Solid oxide fuel cell power plant having a fixed contact oxidation catalyzed section of a multi-section cathode air heat exchanger

    DOEpatents

    Saito, Kazuo; Lin, Yao

    2015-02-17

    The multi-section cathode air heat exchanger (102) includes at least a first heat exchanger section (104), and a fixed contact oxidation catalyzed section (126) secured adjacent each other in a stack association. Cool cathode inlet air flows through cool air channels (110) of the at least first (104) and oxidation catalyzed sections (126). Hot anode exhaust flows through hot air channels (124) of the oxidation catalyzed section (126) and is combusted therein. The combusted anode exhaust then flows through hot air channels (112) of the first section (104) of the cathode air heat exchanger (102). The cool and hot air channels (110, 112) are secured in direct heat exchange relationship with each other so that temperatures of the heat exchanger (102) do not exceed 800.degree. C. to minimize requirements for using expensive, high-temperature alloys.

  6. Korean Affairs Report, Number 289

    DTIC Science & Technology

    1983-06-23

    62 MEDIA AND THE ARTS NODONG SINMUN on Film Revolution Under Party Center (KCNA, 5 Jun 83) 64 DPRK Publishes Magazine AGE OF CHAJUSONG No...efforts to put down the anti-U.S. and antigovernment struggle with bayonets, it can never snuff out the people’s firm will to achieve democracy and...MEDIA AND THE ARTS NODONG SINMUN ON FILM REVOLUTION UNDER PARTY CENTER SK051124 Pyongyang KCNA in English 1107 GMT 5 Jun 83 [Text] Pyongyang, 5 Jun

  7. Effectiveness of the Physical Education Curriculum at the United States Military Academy in Preparing Its Women Graduates

    DTIC Science & Technology

    1994-01-01

    activities as calisthenics , swimming, bayonet drills, fencing, and gymnastics. Unfortunately, this program was in place for only one year. The onset of...fall); basketball, boxing, street hockey, swimming, and wallyball (volleyball played on a racquetball court) (winter); cross country, flickerball...improve the running ability of new cadets; female new cadets used the lighter M16 rifle during rifle calisthenics in CBT II; and fewer hills were run during

  8. Oscillating-Coolant Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Scotti, Stephen J.; Blosser, Max L.; Camarda, Charles J.

    1992-01-01

    Devices useful in situations in which heat pipes inadequate. Conceptual oscillating-coolant heat exchanger (OCHEX) transports heat from its hotter portions to cooler portions. Heat transported by oscillation of single-phase fluid, called primary coolant, in coolant passages. No time-averaged flow in tubes, so either heat removed from end reservoirs on every cycle or heat removed indirectly by cooling sides of channels with another coolant. Devices include leading-edge cooling devices in hypersonic aircraft and "frost-free" heat exchangers. Also used in any situation in which heat pipe used and in other situations in which heat pipes not usable.

  9. Emergency heat removal system for a nuclear reactor

    DOEpatents

    Dunckel, Thomas L.

    1976-01-01

    A heat removal system for nuclear reactors serving as a supplement to an Emergency Core Cooling System (ECCS) during a Loss of Coolant Accident (LOCA) comprises a plurality of heat pipes having one end in heat transfer relationship with either the reactor pressure vessel, the core support grid structure or other in-core components and the opposite end located in heat transfer relationship with a heat exchanger having heat transfer fluid therein. The heat exchanger is located external to the pressure vessel whereby excessive core heat is transferred from the above reactor components and dissipated within the heat exchanger fluid.

  10. Energy efficient data center liquid cooling with geothermal enhancement

    DOEpatents

    Chainer, Timothy J.; Parida, Pritish R.

    2017-11-07

    A data center cooling system is operated in a first mode, and has an indoor portion wherein heat is absorbed from components in the data center by a heat transfer fluid, and an outdoor heat exchanger portion and a geothermal heat exchanger portion. The first mode includes ambient air cooling of the heat transfer fluid in the outdoor heat exchanger portion and/or geothermal cooling of the heat transfer fluid in the geothermal heat exchanger portion. Based on an appropriate metric, a determination is made that a switch should be made from the first mode to a second mode; and, in response, the data center cooling system is switched to the second mode. The second mode is different than the first mode.

  11. Fouling reduction characteristics of a no-distributor-fluidized-bed heat exchanger for flue gas heat recovery

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jun, Y.D.; Lee, K.B.; Islam, S.Z.

    2008-07-01

    In conventional flue gas heat recovery systems, the fouling by fly ashes and the related problems such as corrosion and cleaning are known to be major drawbacks. To overcome these problems, a single-riser no-distributor-fluidized-bed heat exchanger is devised and studied. Fouling and cleaning tests are performed for a uniquely designed fluidized bed-type heat exchanger to demonstrate the effect of particles on the fouling reduction and heat transfer enhancement. The tested heat exchanger model (1 m high and 54 mm internal diameter) is a gas-to-water type and composed of a main vertical tube and four auxiliary tubes through which particles circulatemore » and transfer heat. Through the present study, the fouling on the heat transfer surface could successfully be simulated by controlling air-to-fuel ratios rather than introducing particles through an external feeder, which produced soft deposit layers with 1 to 1.5 mm thickness on the inside pipe wall. Flue gas temperature at the inlet of heat exchanger was maintained at 450{sup o}C at the gas volume rate of 0.738 to 0.768 CMM (0.0123 to 0.0128 m{sup 3}/sec). From the analyses of the measured data, heat transfer performances of the heat exchanger before and after fouling and with and without particles were evaluated. Results showed that soft deposits were easily removed by introducing glass bead particles, and also heat transfer performance increased two times by the particle circulation. In addition, it was found that this type of heat exchanger had high potential to recover heat of waste gases from furnaces, boilers, and incinerators effectively and to reduce fouling related problems.« less

  12. The New S-RAM Air Variable Compressor/Expander for Heat Pump and Waste Heat to Power Application

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dehoff, Ryan R; Jestings, Lee; Conde, Ricardo

    S-RAM Dynamics (S-RAM) has designed an innovative heat pump system targeted for commercial and industrial applications. This new heat pump system is more efficient than anything currently on the market and utilizes air as the refrigerant instead of hydrofluorocarbon (HFC) refrigerants, leading to lower operating costs, minimal environmental costs or concerns, and lower maintenance costs. The heat pumps will be manufactured in the United States. This project was aimed at determining the feasibility of utilizing additive manufacturing to make the heat exchanger device for the new heat pump system. ORNL and S-RAM Dynamics collaborated on determining the prototype performance andmore » subsequently printing of the prototype using additive manufacturing. Complex heat exchanger designs were fabricated using the Arcam electron beam melting (EBM) powder bed technology using Ti-6Al-4V material. An ultrasonic welding system was utilized in order to remove the powder from the small openings of the heat exchanger. The majority of powder in the small chambers was removed, however, the amount of powder remaining in the heat exchanger was a function of geometry. Therefore, only certain geometries of heat exchangers could be fabricated. SRAM Dynamics evaluated a preliminary heat exchanger design. Although the results of the additive manufacturing of the heat exchanger were not optimum, a less complex geometry was demonstrated. A sleeve valve was used as a demonstration piece, as engine designs from S-RAM Dynamics require the engine to have a very high density. Preliminary designs of this geometry were successfully fabricated using the EBM technology.« less

  13. Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mittereder, N.; Poerschke, A.

    2013-11-01

    This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHPmore » in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season. Upon completion of the monitoring phase, measurements revealed that the initial TRNSYS simulated horizontal sub-slab ground loop heat exchanger fluid temperatures and heat transfer rates differed from the measured values. To determine the cause of this discrepancy, an updated model was developed utilizing a new TRNSYS subroutine for simulating sub-slab heat exchangers. Measurements of fluid temperature, soil temperature, and heat transfer were used to validate the updated model.« less

  14. Micro-structured heat exchanger for cryogenic mixed refrigerant cycles

    NASA Astrophysics Data System (ADS)

    Gomse, D.; Reiner, A.; Rabsch, G.; Gietzelt, T.; Brandner, J. J.; Grohmann, S.

    2017-12-01

    Mixed refrigerant cycles (MRCs) offer a cost- and energy-efficient cooling method for the temperature range between 80 and 200 K. The performance of MRCs is strongly influenced by entropy production in the main heat exchanger. High efficiencies thus require small temperature gradients among the fluid streams, as well as limited pressure drop and axial conduction. As temperature gradients scale with heat flux, large heat transfer areas are necessary. This is best achieved with micro-structured heat exchangers, where high volumetric heat transfer areas can be realized. The reliable design of MRC heat exchangers is challenging, since two-phase heat transfer and pressure drop in both fluid streams have to be considered simultaneously. Furthermore, only few data on the convective boiling and condensation kinetics of zeotropic mixtures is available in literature. This paper presents a micro-structured heat exchanger designed with a newly developed numerical model, followed by experimental results on the single-phase pressure drop and their implications on the hydraulic diameter.

  15. Heat transfer and pressure drop characteristics of nanofluids in a plate heat exchanger.

    PubMed

    Kwon, Y H; Kim, D; Li, C G; Lee, J K; Hong, D S; Lee, J G; Lee, S H; Cho, Y H; Kim, S H

    2011-07-01

    In this paper, the heat transfer characteristics and pressure drop of the ZnO and Al2O3 nanofluids in a plate heat exchanger were studied. The experimental conditions were 100-500 Reynolds number and the respective volumetric flow rates. The working temperature of the heat exchanger was within 20-40 degrees C. The measured thermophysical properties, such as thermal conductivity and kinematic viscosity, were applied to the calculation of the convective heat transfer coefficient of the plate heat exchanger employing the ZnO and Al2O3 nanofluids made through a two-step method. According to the Reynolds number, the overall heat transfer coefficient for 6 vol% Al2O3 increased to 30% because at the given viscosity and density of the nanofluids, they did not have the same flow rates. At a given volumetric flow rate, however, the performance did not improve. After the nanofluids were placed in the plate heat exchanger, the experimental results pertaining to nanofluid efficiency seemed inauspicious.

  16. A Project to Design and Build Compact Heat Exchangers

    ERIC Educational Resources Information Center

    Davis, Richard A.

    2005-01-01

    Students designed and manufactured compact, shell-and-tube heat exchangers in a project-based learning exercise integrated with our heat transfer course. The heat exchangers were constructed from common building materials available at home improvement centers. The cost of materials for a device was less than $20. The project gave students…

  17. Molten metal holder furnace and casting system incorporating the molten metal holder furnace

    DOEpatents

    Kinosz, Michael J.; Meyer, Thomas N.

    2003-02-11

    A bottom heated holder furnace (12) for containing a supply of molten metal includes a storage vessel (30) having sidewalls (32) and a bottom wall (34) defining a molten metal receiving chamber (36). A furnace insulating layer (42) lines the molten metal receiving chamber (36). A thermally conductive heat exchanger block (54) is located at the bottom of the molten metal receiving chamber (36) for heating the supply of molten metal. The heat exchanger block (54) includes a bottom face (65), side faces (66), and a top face (67). The heat exchanger block (54) includes a plurality of electrical heaters (70) extending therein and projecting outward from at least one of the faces of the heat exchanger block (54), and further extending through the furnace insulating layer (42) and one of the sidewalls (32) of the storage vessel (30) for connection to a source of electrical power. A sealing layer (50) covers the bottom face (65) and side faces (66) of the heat exchanger block (54) such that the heat exchanger block (54) is substantially separated from contact with the furnace insulating layer (42).

  18. Numerical studies on sizing/ rating of plate fin heat exchangers for a modified Claude cycle based helium liquefier/ refrigerator

    NASA Astrophysics Data System (ADS)

    Goyal, M.; Chakravarty, A.; Atrey, M. D.

    2017-02-01

    Performance of modern helium refrigeration/ liquefaction systems depends significantly on the effectiveness of heat exchangers. Generally, compact plate fin heat exchangers (PFHE) having very high effectiveness (>0.95) are used in such systems. Apart from basic fluid film resistances, various secondary parameters influence the sizing/ rating of these heat exchangers. In the present paper, sizing calculations are performed, using in-house developed numerical models/ codes, for a set of high effectiveness PFHE for a modified Claude cycle based helium liquefier/ refrigerator operating in the refrigeration mode without liquid nitrogen (LN2) pre-cooling. The combined effects of secondary parameters like axial heat conduction through the heat exchanger metal matrix, parasitic heat in-leak from surroundings and variation in the fluid/ metal properties are taken care of in the sizing calculation. Numerical studies are carried out to predict the off-design performance of the PFHEs in the refrigeration mode with LN2 pre-cooling. Iterative process cycle calculations are also carried out to obtain the inlet/ exit state points of the heat exchangers.

  19. Comparison of heat exchanger and solar block wall in a swine nursery

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jones, D.D.; Friday, W.H.; Thieme, R.H.

    1984-01-01

    A pig nursery building was divided into two equal rooms, one with a heat exchanger and one with a solar block wall. The average air inlet temperatures were 16.4/sup 0/C in the heat exchanger room and 11.9/sup 0/C in the solar heated room. Supplemental heating costs were 67% higher in the solar block wall room.

  20. 40 CFR 63.11495 - What are the management practices and other requirements?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... repair. (b) Small heat exchange systems. For each heat exchange system subject to this subpart with a...) You must develop and operate in accordance with a heat exchange system inspection plan. The plan must...

  1. 40 CFR 63.11495 - What are the management practices and other requirements?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... repair. (b) Small heat exchange systems. For each heat exchange system subject to this subpart with a...) You must develop and operate in accordance with a heat exchange system inspection plan. The plan must...

  2. Numerical Investigation for Strengthening Heat Transfer Mechanism of the Tube-Row Heat Exchanger in a Compact Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Zhang, Zheng; Chen, Zijian; Liu, Hongwu; Yue, Hao; Chen, Dongbo; Qin, Delei

    2018-04-01

    According to the basic principle of heat transfer enhancement, a 1-kW compact thermoelectric generator (TEG) is proposed that is suitable for use at high temperatures and high flow speeds. The associated heat exchanger has a tube-row structure with a guide-plate to control the thermal current. The heat exchanger has a volume of 7 L, and the TEG has a mass of 8 kg (excluding the thermoelectric modules (TEMs)). In this paper, the heat transfer process of the tube-row exchanger is modeled and analyzed numerically; and the influences of its structure on the heat transfer and temperature status of the TEMs are investigated. The results show that use of the thin - wall pipes and increase of surface roughness inside the pipes are effective ways to improve the heat transfer efficiency, obtain the rated surface temperature, and make the TEG compact and lightweight. Furthermore, under the same conditions, the calculated results are compared with the data of a fin heat exchanger. The comparison results show that the volume and mass of the tube-row heat exchanger are 19% and 33% lower than those of the fin type unit, and that the pressure drop is reduced by 16%. In addition, the average temperature in the tube-row heat exchanger is increased by 15°C and the average temperature difference is increased by 19°C; the tube-row TEG has a more compact volume and better temperature characteristics.

  3. Numerical Investigation for Strengthening Heat Transfer Mechanism of the Tube-Row Heat Exchanger in a Compact Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Zhang, Zheng; Chen, Zijian; Liu, Hongwu; Yue, Hao; Chen, Dongbo; Qin, Delei

    2018-06-01

    According to the basic principle of heat transfer enhancement, a 1-kW compact thermoelectric generator (TEG) is proposed that is suitable for use at high temperatures and high flow speeds. The associated heat exchanger has a tube-row structure with a guide-plate to control the thermal current. The heat exchanger has a volume of 7 L, and the TEG has a mass of 8 kg (excluding the thermoelectric modules (TEMs)). In this paper, the heat transfer process of the tube-row exchanger is modeled and analyzed numerically; and the influences of its structure on the heat transfer and temperature status of the TEMs are investigated. The results show that use of the thin - wall pipes and increase of surface roughness inside the pipes are effective ways to improve the heat transfer efficiency, obtain the rated surface temperature, and make the TEG compact and lightweight. Furthermore, under the same conditions, the calculated results are compared with the data of a fin heat exchanger. The comparison results show that the volume and mass of the tube-row heat exchanger are 19% and 33% lower than those of the fin type unit, and that the pressure drop is reduced by 16%. In addition, the average temperature in the tube-row heat exchanger is increased by 15°C and the average temperature difference is increased by 19°C; the tube-row TEG has a more compact volume and better temperature characteristics.

  4. A small and light weight heat exchanger for on-board helium refrigerator

    NASA Technical Reports Server (NTRS)

    Koizumi, T.; Takahashi, M.; Uchida, T.; Kanazawa, Y.; Suzuki, M.

    1983-01-01

    A small and light weight heat exchanger used for small helium refrigerator has been developed by Sumitomo Heavy Industries, Ltd. This heat exchanger is a laminated metal heat exchanger which consists of perforated aluminum metal plates and glassfiber reinforced plastic separators. The size is from 100 mm to 28 mm in diameter and about 300 mm in length. The weight is from 2.5 kg to 0.6 kg. Also it can be used between room temperature and liquid helium temperature. The thermal efficiency obtained has been more than 96%. The heat exchanger has been practically used for on-board helium refrigerator in Japanese National Railways' superconducting magnetic levitated trains.

  5. Heat extraction from salinity-gradient solar ponds using heat pipe heat exchangers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tundee, Sura; Terdtoon, Pradit; Sakulchangsatjatai, Phrut

    This paper presents the results of experimental and theoretical analysis on the heat extraction process from solar pond by using the heat pipe heat exchanger. In order to conduct research work, a small scale experimental solar pond with an area of 7.0 m{sup 2} and a depth of 1.5 m was built at Khon Kaen in North-Eastern Thailand (16 27'N102 E). Heat was successfully extracted from the lower convective zone (LCZ) of the solar pond by using a heat pipe heat exchanger made from 60 copper tubes with 21 mm inside diameter and 22 mm outside diameter. The length ofmore » the evaporator and condenser section was 800 mm and 200 mm respectively. R134a was used as the heat transfer fluid in the experiment. The theoretical model was formulated for the solar pond heat extraction on the basis of the energy conservation equations and by using the solar radiation data for the above location. Numerical methods were used to solve the modeling equations. In the analysis, the performance of heat exchanger is investigated by varying the velocity of inlet air used to extract heat from the condenser end of the heat pipe heat exchanger (HPHE). Air velocity was found to have a significant influence on the effectiveness of heat pipe heat exchanger. In the present investigation, there was an increase in effectiveness by 43% as the air velocity was decreased from 5 m/s to 1 m/s. The results obtained from the theoretical model showed good agreement with the experimental data. (author)« less

  6. The predictive protective control of the heat exchanger

    NASA Astrophysics Data System (ADS)

    Nevriva, Pavel; Filipova, Blanka; Vilimec, Ladislav

    2016-06-01

    The paper deals with the predictive control applied to flexible cogeneration energy system FES. FES was designed and developed by the VITKOVICE POWER ENGINEERING joint-stock company and represents a new solution of decentralized cogeneration energy sources. In FES, the heating medium is flue gas generated by combustion of a solid fuel. The heated medium is power gas, which is a gas mixture of air and water steam. Power gas is superheated in the main heat exchanger and led to gas turbines. To protect the main heat exchanger against damage by overheating, the novel predictive protective control based on the mathematical model of exchanger was developed. The paper describes the principle, the design and the simulation of the predictive protective method applied to main heat exchanger of FES.

  7. 40 CFR 63.1086 - How must I monitor for leaks to cooling water?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... exchange system or any combinations of heat exchangers such that, based on the rate of cooling water at the... detected a leak. (b) Individual heat exchangers. Monitor the cooling water at the entrance and exit of each heat exchanger for the HAP in Table 1 to this subpart (either total or speciated) or other...

  8. 40 CFR 63.1086 - How must I monitor for leaks to cooling water?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... exchange system or any combinations of heat exchangers such that, based on the rate of cooling water at the... detected a leak. (b) Individual heat exchangers. Monitor the cooling water at the entrance and exit of each heat exchanger for the HAP in Table 1 to this subpart (either total or speciated) or other...

  9. 40 CFR 63.1086 - How must I monitor for leaks to cooling water?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... exchange system or any combinations of heat exchangers such that, based on the rate of cooling water at the... detected a leak. (b) Individual heat exchangers. Monitor the cooling water at the entrance and exit of each heat exchanger for the HAP in Table 1 to this subpart (either total or speciated) or other...

  10. 40 CFR 63.1086 - How must I monitor for leaks to cooling water?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... exchange system or any combinations of heat exchangers such that, based on the rate of cooling water at the... detected a leak. (b) Individual heat exchangers. Monitor the cooling water at the entrance and exit of each heat exchanger for the HAP in Table 1 to this subpart (either total or speciated) or other...

  11. Thermal management systems and methods

    DOEpatents

    Gering, Kevin L.; Haefner, Daryl R.

    2006-12-12

    A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided.

  12. Study on Fins' Effect of Boiling Flow in Millimeter Channel Heat Exchanger

    NASA Astrophysics Data System (ADS)

    Watanabe, Satoshi

    2005-11-01

    Recently, a lot of researches about compact heat exchangers with mini-channels have been carried out with the hope of obtaining a high-efficiency heat transfer, due to the higher ratio of surface area than existing heat exchangers. However, there are many uncertain phenomena in fields such as boiling flow in mini-channels. Thus, in order to understand the boiling flow in mini-channels to design high-efficiency heat exchangers, this work focused on the visualization measurement of boiling flow in a millimeter channel. A transparent acrylic channel (heat exchanger form), high-speed camera (2000 fps at 1024 x 1024 pixels), and halogen lamp (backup light) were used as the visualization system. The channel's depth is 2 mm, width is 30 mm, and length is 400 mm. In preparation for commercial use, two types of channels were experimented on: a fins type and a normal slit type (without fins). The fins are circular cylindrical obstacles (diameter is 5 mm) to promote heat transfer, set in a triangular array (distance between each center point is 10 mm). Especially in this work, boiling flow and heat transfer promotion in the millimeter channel heat exchanger with fins was evaluated using a high-speed camera.

  13. Wire-packed heat exchangers for dilution refrigerators.

    PubMed

    Polturak, E; Rappaport, M; Rosenbaum, R

    1978-03-01

    Very simple wire-packed step heat exchangers for dilution refrigerators are described. No sintering is used in fabrication. Flow impedances and thermal resistance between the liquid and the copper wires are low. A refrigerator with five wire-packed heat exchangers in addition to a countercurrent heat exchanger attains a temperature of 11.4 mK with a single mixing chamber and 6.1 mK with two mixing chambers. High cooling power is achieved at modest (3)He circulation rates.

  14. Test Results of Heat Exchanger Cleaning in Support of Ocean Thermal Energy Conversion.

    DTIC Science & Technology

    1980-12-01

    tests evaluated the performance of three in-situ cleaning techniques in two potential heat exchanger materials ...1-6. 41Mann, M. J., 1979, "Possible Cu-Ni-Clad Steel Material and Abrasive Slurry Cleaning System for Plate-Fin-Type OTEC Heat Exchangers ," in...of a Shell-less Folded Aluminum Tube, OTEC Heat Exchanger ," Proceedings of the Sixth OTEC Conference, Washington, DC, June 19-22, 1978, pp 12.8-1

  15. Seven-effect absorption refrigeration

    DOEpatents

    DeVault, Robert C.; Biermann, Wendell J.

    1989-01-01

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

  16. Seven-effect absorption refrigeration

    DOEpatents

    DeVault, R.C.; Biermann, W.J.

    1989-05-09

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

  17. Thermal induced flow oscillations in heat exchangers for supercritical fluids

    NASA Technical Reports Server (NTRS)

    Friedly, J. C.; Manganaro, J. L.; Krueger, P. G.

    1972-01-01

    Analytical model has been developed to predict possible unstable behavior in supercritical heat exchangers. From complete model, greatly simplified stability criterion is derived. As result of this criterion, stability of heat exchanger system can be predicted in advance.

  18. Modelling of Technological Solutions to 4th Generation DH Systems

    NASA Astrophysics Data System (ADS)

    Vigants, Edgars; Prodanuks, Toms; Vigants, Girts; Veidenbergs, Ivars; Blumberga, Dagnija

    2017-11-01

    Flue gas evaporation and condensing processes are investigated in a direct contact heat exchanger - condensing unit, which is installed after a furnace. By using equations describing processes of heat and mass transfer, as well as correlation coherences for determining wet gas parameters, a model is formed to create a no-filling, direct contact heat exchanger. Results of heating equipment modelling and experimental research on the gas condensing unit show, that the capacity of the heat exchanger increases, when return temperature of the district heating network decreases. In order to explain these alterations in capacity, the character of the changes in water vapour partial pressure, in the propelling force of mass transfer, in gas and water temperatures and in the determining parameters of heat transfer are used in this article. The positive impact on the direct contact heat exchanger by the decreased district heating (DH) network return temperature shows that introduction of the 4th generation DH system increases the energy efficiency of the heat exchanger. In order to make an assessment, the methodology suggested in the paper can be used in each particular situation.

  19. Heat exchanger with transpired, highly porous fins

    DOEpatents

    Kutscher, Charles F.; Gawlik, Keith

    2002-01-01

    The heat exchanger includes a fin and tube assembly with increased heat transfer surface area positioned within a hollow chamber of a housing to provide effective heat transfer between a gas flowing within the hollow chamber and a fluid flowing in the fin and tube assembly. A fan is included to force a gas, such as air, to flow through the hollow chamber and through the fin and tube assembly. The fin and tube assembly comprises fluid conduits to direct the fluid through the heat exchanger, to prevent mixing with the gas, and to provide a heat transfer surface or pathway between the fluid and the gas. A heat transfer element is provided in the fin and tube assembly to provide extended heat transfer surfaces for the fluid conduits. The heat transfer element is corrugated to form fins between alternating ridges and grooves that define flow channels for directing the gas flow. The fins are fabricated from a thin, heat conductive material containing numerous orifices or pores for transpiring the gas out of the flow channel. The grooves are closed or only partially open so that all or substantially all of the gas is transpired through the fins so that heat is exchanged on the front and back surfaces of the fins and also within the interior of the orifices, thereby significantly increasing the available the heat transfer surface of the heat exchanger. The transpired fins also increase heat transfer effectiveness of the heat exchanger by increasing the heat transfer coefficient by disrupting boundary layer development on the fins and by establishing other beneficial gas flow patterns, all at desirable pressure drops.

  20. Pumped two-phase heat transfer loop

    NASA Technical Reports Server (NTRS)

    Edelstein, Fred

    1988-01-01

    A pumped loop two-phase heat transfer system, operating at a nearly constant temperature throughout, includes several independently operating grooved capillary heat exchanger plates supplied with working fluid through independent flow modulation valves connected to a liquid supply line, a vapor line for collecting vapor from the heat exchangers, a condenser between the vapor and the liquid lines, and a fluid circulating pump between the condenser and the heat exchangers.

  1. Pumped two-phase heat transfer loop

    NASA Technical Reports Server (NTRS)

    Edelstein, Fred (Inventor)

    1987-01-01

    A pumped loop two-phase heat transfer system, operating at a nearly constant temperature throughout, includes a plurality of independently operating grooved capillary heat exchanger plates supplied with working fluid through independent flow modulation valves connected to a liquid supply line, a vapor line for collecting vapor from the heat exchangers, a condenser between the vapor and the liquid lines, and a fluid circulating pump between the condenser and the heat exchangers.

  2. Open-loop heat-recovery dryer

    DOEpatents

    TeGrotenhuis, Ward Evan

    2013-11-05

    A drying apparatus is disclosed that includes a drum and an open-loop airflow pathway originating at an ambient air inlet, passing through the drum, and terminating at an exhaust outlet. A passive heat exchanger is included for passively transferring heat from air flowing from the drum toward the exhaust outlet to air flowing from the ambient air inlet toward the drum. A heat pump is also included for actively transferring heat from air flowing from the passive heat exchanger toward the exhaust outlet to air flowing from the passive heat exchanger toward the drum. A heating element is also included for further heating air flowing from the heat pump toward the drum.

  3. Power generation plant integrating concentrated solar power receiver and pressurized heat exchanger

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sakadjian, Bartev B; Flynn, Thomas J; Hu, Shengteng

    A power plant includes a solar receiver heating solid particles, a standpipe receiving solid particles from the solar receiver, a pressurized heat exchanger heating working fluid by heat transfer through direct contact with heated solid particles flowing out of the bottom of the standpipe, and a flow path for solid particles from the bottom of the standpipe into the pressurized heat exchanger that is sealed by a pressure P produced at the bottom of the standpipe by a column of heated solid particles of height H. The flow path may include a silo or surge tank comprising a pressure vesselmore » connected to the bottom of the standpipe, and a non-mechanical valve. The power plant may further include a turbine driven by heated working fluid discharged from the pressurized heat exchanger, and a compressor driven by the turbine.« less

  4. Investigation of two-phase heat transfer coefficients of argon-freon cryogenic mixed refrigerants

    NASA Astrophysics Data System (ADS)

    Baek, Seungwhan; Lee, Cheonkyu; Jeong, Sangkwon

    2014-11-01

    Mixed refrigerant Joule Thomson refrigerators are widely used in various kinds of cryogenic systems these days. Although heat transfer coefficient estimation for a multi-phase and multi-component fluid in the cryogenic temperature range is necessarily required in the heat exchanger design of mixed refrigerant Joule Thomson refrigerators, it has been rarely discussed so far. In this paper, condensation and evaporation heat transfer coefficients of argon-freon mixed refrigerant are measured in a microchannel heat exchanger. A Printed Circuit Heat Exchanger (PCHE) with 340 μm hydraulic diameter has been developed as a compact microchannel heat exchanger and utilized in the experiment. Several two-phase heat transfer coefficient correlations are examined to discuss the experimental measurement results. The result of this paper shows that cryogenic two-phase mixed refrigerant heat transfer coefficients can be estimated by conventional two-phase heat transfer coefficient correlations.

  5. Analysis of Heat Transfers inside Counterflow Plate Heat Exchanger Augmented by an Auxiliary Fluid Flow

    PubMed Central

    Khaled, A.-R. A.

    2014-01-01

    Enhancement of heat transfers in counterflow plate heat exchanger due to presence of an intermediate auxiliary fluid flow is investigated. The intermediate auxiliary channel is supported by transverse conducting pins. The momentum and energy equations for the primary fluids are solved numerically and validated against a derived approximate analytical solution. A parametric study including the effect of the various plate heat exchanger, and auxiliary channel dimensionless parameters is conducted. Different enhancement performance indicators are computed. The various trends of parameters that can better enhance heat transfer rates above those for the conventional plate heat exchanger are identified. Large enhancement factors are obtained under fully developed flow conditions. The maximum enhancement factors can be increased by above 8.0- and 5.0-fold for the step and exponential distributions of the pins, respectively. Finally, counterflow plate heat exchangers with auxiliary fluid flows are recommended over the typical ones if these flows can be provided with the least cost. PMID:24719572

  6. Analysis of heat transfers inside counterflow plate heat exchanger augmented by an auxiliary fluid flow.

    PubMed

    Khaled, A-R A

    2014-01-01

    Enhancement of heat transfers in counterflow plate heat exchanger due to presence of an intermediate auxiliary fluid flow is investigated. The intermediate auxiliary channel is supported by transverse conducting pins. The momentum and energy equations for the primary fluids are solved numerically and validated against a derived approximate analytical solution. A parametric study including the effect of the various plate heat exchanger, and auxiliary channel dimensionless parameters is conducted. Different enhancement performance indicators are computed. The various trends of parameters that can better enhance heat transfer rates above those for the conventional plate heat exchanger are identified. Large enhancement factors are obtained under fully developed flow conditions. The maximum enhancement factors can be increased by above 8.0- and 5.0-fold for the step and exponential distributions of the pins, respectively. Finally, counterflow plate heat exchangers with auxiliary fluid flows are recommended over the typical ones if these flows can be provided with the least cost.

  7. Design and fabrication of a 3-D printable counter-low/precipitation heat exchanger for use with a novel off-grid solid state refrigeration system

    NASA Astrophysics Data System (ADS)

    Ryan, Sean Thomas

    Off-grid refrigeration technologies are currently limited to either vapor-compression cycles driven by photovoltaics or solar thermal absorption cycles. Rebound Technologies has recently developed a novel off-grid refrigeration system called Sunchill(TM) for agricultural applications in humid environments in the developing world. The Sunchill(TM) refrigeration system utilizes the daily high and low temperatures to drive a 24 hour refrigeration cycle. Cooling is provided by the dissolution of an endothermic salt, sodium carbonate decahydrate. Once the salt is solvated and cooling is delivered to freshly harvest crops, the system is "recharged" in a multi-step process that relies on a solar collector, an air-gap membrane unit and a heat exchanger. The heat exchanger, which is the focus of this thesis, is required to remove 36.6 MJ of heat over a twelve hour period in order to "recharge" the system. The heat exchanger is also required to transfer heat from a fresh water stream to a cold brine solution to generate the cold water necessary to submerse and cool harvested crops. To provide a sustainable technology to the target community, the feasibility of fabricating the heat exchanger via the low cost 3-D printing method of fused filament fabrication (FFF) was examined. This thesis presents the design, development, and manufacturing considerations that were performed in support of developing a waterproof, counter-flow, 3-D printable heat exchanger. Initial geometries and performance were modeled by constructing a linear thermal resistance network with truncating temperatures of 30°C (saturated brine temperature) and 18°C (average daily low temperature). The required surface area of the heat exchanger was found to be 20.46 m2 to remove the required 36.6 MJ of heat. Iterative print tests were conducted to arrive at the wall thickness, hexagon shape, and double wall structure of the heat exchanger. A laboratory-scale heat exchanger was fabricated using a Lulzbot Taz 4 printer from acrylonitrile butadiene styrene (ABS) polymer. Performance was verified empirically for the laboratory-scale unit. A heat transfer rate of 22.8 W was obtained at a flow rate of 0.00075 kg/s. The results of this thesis demonstrate the feasibility of manufacturing low cost heat exchangers using additive manufacturing techniques.

  8. Entropy Generation in Regenerative Systems

    NASA Technical Reports Server (NTRS)

    Kittel, Peter

    1995-01-01

    Heat exchange to the oscillating flows in regenerative coolers generates entropy. These flows are characterized by oscillating mass flows and oscillating temperatures. Heat is transferred between the flow and heat exchangers and regenerators. In the former case, there is a steady temperature difference between the flow and the heat exchangers. In the latter case, there is no mean temperature difference. In this paper a mathematical model of the entropy generated is developed for both cases. Estimates of the entropy generated by this process are given for oscillating flows in heat exchangers and in regenerators. The practical significance of this entropy is also discussed.

  9. Hydromechanics and heat and mass exchange in weightlessness (Russian book): Table of contents

    NASA Technical Reports Server (NTRS)

    Avduyevskiy, V. S.; Poleshayev, V. I.

    1983-01-01

    The table of contents is given for a book on hydromechanics and heat and mass exchange in weightlessness. The book covers such subjects as hydromechanics, convection and heat and mass exchange, and technological experiments and complicated systems.

  10. Heat exchanger for solar water heaters

    NASA Technical Reports Server (NTRS)

    Cash, M.; Krupnick, A. C.

    1977-01-01

    Proposed efficient double-walled heat exchanger prevents contamination of domestic water supply lines and indicates leakage automatically in solar as well as nonsolar heat sources using water as heat transfer medium.

  11. High temperature heat exchanger studies for applications to gas turbines

    NASA Astrophysics Data System (ADS)

    Min, June Kee; Jeong, Ji Hwan; Ha, Man Yeong; Kim, Kui Soon

    2009-12-01

    Growing demand for environmentally friendly aero gas-turbine engines with lower emissions and improved specific fuel consumption can be met by incorporating heat exchangers into gas turbines. Relevant researches in such areas as the design of a heat exchanger matrix, materials selection, manufacturing technology, and optimization by a variety of researchers have been reviewed in this paper. Based on results reported in previous studies, potential heat exchanger designs for an aero gas turbine recuperator, intercooler, and cooling-air cooler are suggested.

  12. Heat exchanger with ceramic elements

    DOEpatents

    Corey, John A.

    1986-01-01

    An annular heat exchanger assembly includes a plurality of low thermal growth ceramic heat exchange members with inlet and exit flow ports on distinct faces. A mounting member locates each ceramic member in a near-annular array and seals the flow ports on the distinct faces into the separate flow paths of the heat exchanger. The mounting member adjusts for the temperature gradient in the assembly and the different coefficients of thermal expansion of the members of the assembly during all operating temperatures.

  13. Analytical Study on Thermal and Mechanical Design of Printed Circuit Heat Exchanger

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yoon, Su-Jong; Sabharwall, Piyush; Kim, Eung-Soo

    2013-09-01

    The analytical methodologies for the thermal design, mechanical design and cost estimation of printed circuit heat exchanger are presented in this study. In this study, three flow arrangements of parallel flow, countercurrent flow and crossflow are taken into account. For each flow arrangement, the analytical solution of temperature profile of heat exchanger is introduced. The size and cost of printed circuit heat exchangers for advanced small modular reactors, which employ various coolants such as sodium, molten salts, helium, and water, are also presented.

  14. Heat exchanger and water tank arrangement for passive cooling system

    DOEpatents

    Gillett, James E.; Johnson, F. Thomas; Orr, Richard S.; Schulz, Terry L.

    1993-01-01

    A water storage tank in the coolant water loop of a nuclear reactor contains a tubular heat exchanger. The heat exchanger has tubesheets mounted to the tank connections so that the tubesheets and tubes may be readily inspected and repaired. Preferably, the tubes extend from the tubesheets on a square pitch and then on a rectangular pitch therebetween. Also, the heat exchanger is supported by a frame so that the tank wall is not required to support all of its weight.

  15. 24 CFR 3280.702 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (in the case of a heat pump) heating system which includes the refrigerant pump (compressor) and the external heat exchanger. Air conditioning evaporator section means a heat exchanger used to cool or (in the case of a heat pump) heat air for use in comfort cooling (or heating) the living space. Air...

  16. 24 CFR 3280.702 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (in the case of a heat pump) heating system which includes the refrigerant pump (compressor) and the external heat exchanger. Air conditioning evaporator section means a heat exchanger used to cool or (in the case of a heat pump) heat air for use in comfort cooling (or heating) the living space. Air...

  17. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ermanoski, Ivan; Orozco, Adrian

    In this report we present the development of a packed particle bed recirculator and heat exchanger. The device is intended to create countercurrent flows of packed particle beds and exchange heat between the flows. The project focused on the design, fabrication, demonstration, and modifications of a simple prototype, in order to attain high levels of heat exchange between particle flows while maintaining an effective particle conveying rate in a scalable package. Despite heat losses in a package not optimized for heat retention, 50% heat recovery was achieved, at a particle conveying efficiency of 40%.

  18. Microchannel crossflow fluid heat exchanger and method for its fabrication

    DOEpatents

    Swift, G.W.; Migliori, A.; Wheatley, J.C.

    1982-08-31

    A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance.

  19. Microchannel crossflow fluid heat exchanger and method for its fabrication

    DOEpatents

    Swift, Gregory W.; Migliori, Albert; Wheatley, John C.

    1985-01-01

    A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance.

  20. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.; Marsala, Joseph

    1994-11-29

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

  1. Probe Measures Fouling As In Heat Exchangers

    NASA Technical Reports Server (NTRS)

    Marner, Wilbur J.; Macdavid, Kenton S.

    1990-01-01

    Combustion deposits reduce transfer of heat. Instrument measures fouling like that on gas side of heat exchanger in direct-fired boiler or heat-recovery system. Heat-flux probe includes tube with embedded meter in outer shell. Combustion gases flow over probe, and fouling accumulates on it, just as fouling would on heat exchanger. Embedded heat-flow meter is sandwich structure in which thin Chromel layers and middle alloy form thermopile. Users determine when fouling approaches unacceptable levels so they schedule cleaning and avoid decreased transfer of heat and increased drop in pressure fouling causes. Avoids cost of premature, unnecessary maintenance.

  2. Heat Exchange, Additive Manufacturing, and Neutron Imaging

    ScienceCinema

    Geoghegan, Patrick

    2018-01-16

    Researchers at the Oak Ridge National Laboratory have captured undistorted snapshots of refrigerants flowing through small heat exchangers, helping them to better understand heat transfer in heating, cooling and ventilation systems.

  3. The combined effects of longitudinal heat conduction, flow nonuniformity and temperature nonuniformity in crossflow plate-fin heat exchangers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ranganayakulu, C.; Seetharamu, K.N.

    An analysis of a crossflow plate-fin compact heat exchanger, accounting for the combined effects of two-dimensional longitudinal heat conduction through the exchanger wall and nonuniform inlet fluid flow and temperature distribution is carried out using a finite element method. A mathematical equation is developed to generate different types of fluid flow/temperature maldistribution models considering the possible deviations in fluid flow. Using these models, the exchanger effectiveness and its deterioration due to the combined effects of longitudinal heat conduction, flow nonuniformity and temperature nonuniformity are calculated for various design and operating conditions of the exchanger. It was found that the performancemore » variations are quite significant in some typical applications.« less

  4. Optimized heat exchange in a CO2 de-sublimation process

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baxter, Larry; Terrien, Paul; Tessier, Pascal

    The present invention is a process for removing carbon dioxide from a compressed gas stream including cooling the compressed gas in a first heat exchanger, introducing the cooled gas into a de-sublimating heat exchanger, thereby producing a first solid carbon dioxide stream and a first carbon dioxide poor gas stream, expanding the carbon dioxide poor gas stream, thereby producing a second solid carbon dioxide stream and a second carbon dioxide poor gas stream, combining the first solid carbon dioxide stream and the second solid carbon dioxide stream, thereby producing a combined solid carbon dioxide stream, and indirectly exchanging heat betweenmore » the combined solid carbon dioxide stream and the compressed gas in the first heat exchanger.« less

  5. Nature's Heat Exchangers.

    ERIC Educational Resources Information Center

    Barnes, George

    1991-01-01

    Discusses the heat-transfer systems of different animals. Systems include heat conduction into the ground, heat transferred by convection, heat exchange in lizards, fish and polar animals, the carotid rete system, electromagnetic radiation from animals and people, and plant and animal fiber optics. (MDH)

  6. Heat-driven acoustic cooling engine having no moving parts

    DOEpatents

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert; Hofler, Thomas J.

    1989-01-01

    A heat-driven acoustic cooling engine having no moving parts receives heat from a heat source. The acoustic cooling engine comprises an elongated resonant pressure vessel having first and second ends. A compressible fluid having a substantial thermal expansion coefficient and capable of supporting an acoustic standing wave is contained in the resonant pressure vessel. The heat source supplies heat to the first end of the vessel. A first heat exchanger in the vessel is spaced-apart from the first end and receives heat from the first end. A first thermodynamic element is adjacent to the first heat exchanger and converts some of the heat transmitted by the first heat exchanger into acoustic power. A second thermodynamic element has a first end located spaced-apart from the first thermodynamic element and a second end farther away from the first thermodynamic element than is its first end. The first end of the second thermodynamic element heats while its second end cools as a consequence of the acoustic power. A second heat exchanger is adjacent to and between the first and second thermodynamic elements. A heat sink outside of the vessel is thermally coupled to and receives heat from the second heat exchanger. The resonant pressure vessel can include a housing less than one-fourth wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir.

  7. Methods of forming thermal management systems and thermal management methods

    DOEpatents

    Gering, Kevin L.; Haefner, Daryl R.

    2012-06-05

    A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided.

  8. Heat exchanger for power generation equipment

    DOEpatents

    Nirmalan, Nirm Velumylm; Bowman, Michael John

    2005-06-14

    A heat exchanger for a turbine is provided wherein the heat exchanger comprises a heat transfer cell comprising a sheet of material having two opposed ends and two opposed sides. In addition, a plurality of concavities are disposed on a surface portion of the sheet of material so as to cause hydrodynamic interactions and affect a heat transfer rate of the turbine between a fluid and the concavities when the fluid is disposed over the concavities.

  9. Expert System For Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Bagby, D. Gordon; Cormier, Reginald A.

    1991-01-01

    Diagnosis simplified for non-engineers. Developmental expert-system computer program assists operator in controlling, monitoring operation, diagnosing malfunctions, and ordering repairs of heat-exchanger system dissipating heat generated by 20-kW radio transmitter. System includes not only heat exchanger but also pumps, fans, sensors, valves, reservoir, and associated plumbing. Program conceived to assist operator while avoiding cost of keeping engineer in full-time attendance. Similar programs developed for heating, ventilating, and air-conditioning systems.

  10. Performance analyses of helical coil heat exchangers. The effect of external coil surface modification on heat exchanger effectiveness

    NASA Astrophysics Data System (ADS)

    Andrzejczyk, Rafał; Muszyński, Tomasz

    2016-12-01

    The shell and coil heat exchangers are commonly used in heating, ventilation, nuclear industry, process plant, heat recovery and air conditioning systems. This type of recuperators benefits from simple construction, the low value of pressure drops and high heat transfer. In helical coil, centrifugal force is acting on the moving fluid due to the curvature of the tube results in the development. It has been long recognized that the heat transfer in the helical tube is much better than in the straight ones because of the occurrence of secondary flow in planes normal to the main flow inside the helical structure. Helical tubes show good performance in heat transfer enhancement, while the uniform curvature of spiral structure is inconvenient in pipe installation in heat exchangers. Authors have presented their own construction of shell and tube heat exchanger with intensified heat transfer. The purpose of this article is to assess the influence of the surface modification over the performance coefficient and effectiveness. The experiments have been performed for the steady-state heat transfer. Experimental data points were gathered for both laminar and turbulent flow, both for co current- and countercurrent flow arrangement. To find optimal heat transfer intensification on the shell-side authors applied the number of transfer units analysis.

  11. 46 CFR 61.10-5 - Pressure vessels in service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... conditions at each inspection for certification: all tubular heat exchangers, hydraulic accumulators, and all...: all tubular heat exchangers, hydraulic accumulators, and all pressure vessels used in refrigeration... normally be subjected to a hydrostatic test: (1) Tubular heat exchangers. (2) Pressure vessels used in...

  12. 46 CFR 61.10-5 - Pressure vessels in service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... conditions at each inspection for certification: all tubular heat exchangers, hydraulic accumulators, and all...: all tubular heat exchangers, hydraulic accumulators, and all pressure vessels used in refrigeration... normally be subjected to a hydrostatic test: (1) Tubular heat exchangers. (2) Pressure vessels used in...

  13. Cryogenic fluid flow instabilities in heat exchangers

    NASA Technical Reports Server (NTRS)

    Fleming, R. B.; Staub, F. W.

    1969-01-01

    Analytical and experimental investigation determines the nature of oscillations and instabilities that occur in the flow of two-phase cryogenic fluids at both subcritical and supercritical pressures in heat exchangers. Test results with varying system parameters suggest certain design approaches with regard to heat exchanger geometry.

  14. 46 CFR 61.10-5 - Pressure vessels in service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... conditions at each inspection for certification: all tubular heat exchangers, hydraulic accumulators, and all...: all tubular heat exchangers, hydraulic accumulators, and all pressure vessels used in refrigeration... normally be subjected to a hydrostatic test: (1) Tubular heat exchangers. (2) Pressure vessels used in...

  15. 46 CFR 61.10-5 - Pressure vessels in service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... conditions at each inspection for certification: all tubular heat exchangers, hydraulic accumulators, and all...: all tubular heat exchangers, hydraulic accumulators, and all pressure vessels used in refrigeration... normally be subjected to a hydrostatic test: (1) Tubular heat exchangers. (2) Pressure vessels used in...

  16. Design Development Analyses in Support of a Heatpipe-Brayton Cycle Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Steeve, Brian; VanDyke, Melissa; Majumdar, Alok; Nguyen, Dalton; Corley, Melissa; Guffee, Ray M.; Kapernick, Richard J.

    2003-01-01

    One of the power systems under consideration for nuclear electric propulsion or as a planetary surface power source is a heatpipe-cooled reactor coupled to a Brayton cycle. In this system, power is transferred from the heatpipes to the Brayton gas via a heat exchanger attached to the heatpipes. This paper discusses the fluid, thermal and structural analyses that were performed in support of the design of the heat exchanger to be tested in the SAFE-100 experimental program at Marshall Space Flight Center. A companion paper, "Mechanical Design and Fabrication of a SAFE-100 Heat Exchanger for use in NASA s Advanced Propulsion Thermal-hydraulic Simulator", presents the fabrication issues and prototyping studies that, together with these analyses, led to the development of this heat exchanger. An important consideration throughout the design development of the heat exchanger was its capability to be utilized for higher power and temperature applications. This paper also discusses this aspect of the design and presents designs for specific applications that are under consideration.

  17. Low GWP Refrigerants Modelling Study for a Room Air Conditioner Having Microchannel Heat Exchangers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shen, Bo; Bhandari, Mahabir S

    Microchannel heat exchangers (MHX) have found great successes in residential and commercial air conditioning applications, being compact heat exchangers, to reduce refrigerant charge and material cost. This investigation aims to extend the application of MHXs in split, room air conditioners (RAC), per fundamental heat exchanger and system modelling. For this paper, microchannel condenser and evaporator models were developed, using a segment-to-segment modelling approach. The microchannel heat exchanger models were integrated to a system design model. The system model is able to predict the performance indices, such as cooling capacity, efficiency, sensible heat ratio, etc. Using the calibrated system and heatmore » exchanger models, we evaluated numerous low GWP (global warming potential) refrigerants. The predicted system performance indices, e.g. cooling efficiency, compressor discharge temperature, and required compressor displacement volume etc., are compared. Suitable replacements for R22 and R-410A for the room air conditioner application are recommended.« less

  18. 40 CFR 63.2490 - What requirements must I meet for heat exchange systems?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... must I meet for heat exchange systems? (a) You must comply with each requirement in Table 10 to this subpart that applies to your heat exchange systems, except as specified in paragraphs (b) and (c) of this... 40 Protection of Environment 12 2011-07-01 2009-07-01 true What requirements must I meet for heat...

  19. 40 CFR 63.2490 - What requirements must I meet for heat exchange systems?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements must I meet for heat exchange systems? (a) You must comply with each requirement in Table 10 to this subpart that applies to your heat exchange systems, except as specified in paragraphs (b) and (c... 40 Protection of Environment 13 2012-07-01 2012-07-01 false What requirements must I meet for heat...

  20. 40 CFR 63.2490 - What requirements must I meet for heat exchange systems?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements must I meet for heat exchange systems? (a) You must comply with each requirement in Table 10 to this subpart that applies to your heat exchange systems, except as specified in paragraphs (b) and (c... 40 Protection of Environment 13 2013-07-01 2012-07-01 true What requirements must I meet for heat...

  1. 40 CFR 63.2490 - What requirements must I meet for heat exchange systems?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... must I meet for heat exchange systems? (a) You must comply with each requirement in Table 10 to this subpart that applies to your heat exchange systems, except as specified in paragraphs (b) and (c) of this... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What requirements must I meet for heat...

  2. 40 CFR 63.2490 - What requirements must I meet for heat exchange systems?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements must I meet for heat exchange systems? (a) You must comply with each requirement in Table 10 to this subpart that applies to your heat exchange systems, except as specified in paragraphs (b) and (c... 40 Protection of Environment 13 2014-07-01 2014-07-01 false What requirements must I meet for heat...

  3. Experimental temperature analysis of simple & hybrid earth air tunnel heat exchanger in series connection at Bikaner Rajasthan India

    NASA Astrophysics Data System (ADS)

    Jakhar, O. P.; Sharma, Chandra Shekhar; Kukana, Rajendra

    2018-05-01

    The Earth Air Tunnel Heat Exchanger System is a passive air-conditioning system which has no side effect on earth climate and produces better cooling effect and heating effect comfortable to human body. It produces heating effect in winter and cooling effect in summer with the minimum power consumption of energy as compare to other air-conditioning devices. In this research paper Temperature Analysis was done on the two systems of Earth Air Tunnel Heat Exchanger experimentally for summer cooling purpose. Both the system was installed at Mechanical Engineering Department Government Engineering College Bikaner Rajasthan India. Experimental results concludes that the Average Air Temperature Difference was found as 11.00° C and 16.27° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively. The Maximum Air Temperature Difference was found as 18.10° C and 23.70° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively. The Minimum Air Temperature Difference was found as 5.20° C and 11.70° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively.

  4. Prototype solar-heated hot water systems and double-walled heat exchangers

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Development progress made on two solar-heated hot water systems and two heat exchangers is reported. The development, manufacture, installation, maintenance, problem resolution, and system evaluation are described.

  5. Towards Organized Disorder: The Evolution of American Infantry Assault Tactics, 1778-1919

    DTIC Science & Technology

    1979-12-17

    military training. 5 3 Many officers who would hold this post would play key roles in shaping infantry tactical doctrine. During Thayer’s admlnis...produce more. Meanwhile Scott would insure that these officers had a tactical system they could use. General Scott was to play a large part in the...Gettysburg in 1863. 5 2Wiley, p. 76. tth 5 3The bayonet played a very small role in Civil War combat compared to the destruction caused by the Minie

  6. Solid Propellant Subscale Burning Rate Analysis Methods for US and Selected NATO Facilities

    DTIC Science & Technology

    2002-01-01

    impossibility of the center of a particle lying closer than its radius from a solid boundary, * Due to surface tension and sedimentation (tends to level...34 effect (for bottom cast or bayonet cast grains) may consist of sedimentation of larger particles against the walls during casting flow, with the...February 2000. 91 Ratti A., "Metodi di Riduzione Dati Balistici per i Boosters a Propellente Solido di Ariane-4 e di Ariane-5," M.Sc. Thesis in Aerospace

  7. Investigation of heat exchangers for energy conversion systems of megawatt-class space power plants

    NASA Astrophysics Data System (ADS)

    Ilmov, D. N.; Mamontov, Yu. N.; Skorohodov, A. S.; Smolyarov, V. A.; Filatov, N. I.

    2016-01-01

    The specifics of operation (high temperatures in excess of 1000 K and large pressure drops of several megapascals between "hot" and "cold" coolant paths) of heat exchangers in the closed circuit of a gasturbine power converter operating in accordance with the Brayton cycle with internal heat recovery are analyzed in the context of construction of space propulsion systems. The design of a heat-exchange matrix made from doubly convex stamped plates with a specific surface relief is proposed. This design offers the opportunity to construct heat exchangers with the required parameters (strength, rigidity, weight, and dimensions) for the given operating conditions. The diagram of the working area of a test bench is presented, and the experimental techniques are outlined. The results of experimental studies of heat exchange and flow regimes in the models of heat exchangers with matrices containing 50 and 300 plates for two pairs of coolants (gas-gas and gas-liquid) are detailed. A criterion equation for the Nusselt number in the range of Reynolds numbers from 200 to 20 000 is proposed. The coefficients of hydraulic resistance for each coolant path are determined as functions of the Reynolds number. It is noted that the pressure in the water path in the "gas-liquid" series of experiments remained almost constant. This suggests that no well-developed processes of vaporization occurred within this heat-exchange matrix design even when the temperature drop between gas and water was as large as tens or hundreds of degrees. The obtained results allow one to design flight heat exchangers for various space power plants.

  8. Absorption heat pump system

    DOEpatents

    Grossman, G.

    1982-06-16

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

  9. Absorption heat pump system

    DOEpatents

    Grossman, Gershon

    1984-01-01

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

  10. High-Pressure Oxygen Generation for Outpost EVA

    NASA Technical Reports Server (NTRS)

    Jeng, Frank; Conger, Bruce; Anderson, Molly

    2008-01-01

    Low Lunar Orbit (LLO) poses unique thermal challenges for the orbiting space craft, particularly regarding the performance of the radiators. The emitted infrared (IR) heat flux from the lunar surface varies drastically from the light side to the dark side of the moon. Due to the extremely high incident IR flux, especially at low beta angles, a radiator is oftentimes unable to reject the vehicle heat load throughout the entire lunar orbit. One solution to this problem is to implement Phase Change Material (PCM) Heat Exchangers. PCM Heat Exchangers act as a "thermal capacitor, storing thermal energy when the radiator is unable to reject the required heat load. The stored energy is then removed from the PCM heat exchanger when the environment is more benign. Because they do not use an expendable resource, such as the feed water used by sublimators and evaporators, PCM Heat Exchangers are ideal for long duration Low Lunar Orbit missions. The Advanced Thermal Control project at JSC is completing a PCM heat exchanger life test to determine whether further technology development is warranted. The life test is being conducted on four nPentadecane, carbon filament heat exchangers. Fluid loop performance, repeatability, and measurement of performance degradation over 2500 meltfreeze cycles will be performed and reported in the current document.

  11. Flow and heat transfer enhancement in tube heat exchangers

    NASA Astrophysics Data System (ADS)

    Sayed Ahmed, Sayed Ahmed E.; Mesalhy, Osama M.; Abdelatief, Mohamed A.

    2015-11-01

    The performance of heat exchangers can be improved to perform a certain heat-transfer duty by heat transfer enhancement techniques. Enhancement techniques can be divided into two categories: passive and active. Active methods require external power, such as electric or acoustic field, mechanical devices, or surface vibration, whereas passive methods do not require external power but make use of a special surface geometry or fluid additive which cause heat transfer enhancement. The majority of commercially interesting enhancement techniques are passive ones. This paper presents a review of published works on the characteristics of heat transfer and flow in finned tube heat exchangers of the existing patterns. The review considers plain, louvered, slit, wavy, annular, longitudinal, and serrated fins. This review can be indicated by the status of the research in this area which is important. The comparison of finned tubes heat exchangers shows that those with slit, plain, and wavy finned tubes have the highest values of area goodness factor while the heat exchanger with annular fin shows the lowest. A better heat transfer coefficient ha is found for a heat exchanger with louvered finned and thus should be regarded as the most efficient one, at fixed pumping power per heat transfer area. This study points out that although numerous studies have been conducted on the characteristics of flow and heat transfer in round, elliptical, and flat tubes, studies on some types of streamlined-tubes shapes are limited, especially on wing-shaped tubes (Sayed Ahmed et al. in Heat Mass Transf 50: 1091-1102, 2014; in Heat Mass Transf 51: 1001-1016, 2015). It is recommended that further detailed studies via numerical simulations and/or experimental investigations should be carried out, in the future, to put further insight to these fin designs.

  12. Co-flow anode/cathode supply heat exchanger for a solid-oxide fuel cell assembly

    DOEpatents

    Haltiner, Jr., Karl J.; Kelly, Sean M.

    2005-11-22

    In a solid-oxide fuel cell assembly, a co-flow heat exchanger is provided in the flow paths of the reformate gas and the cathode air ahead of the fuel cell stack, the reformate gas being on one side of the exchanger and the cathode air being on the other. The reformate gas is at a substantially higher temperature than is desired in the stack, and the cathode gas is substantially cooler than desired. In the co-flow heat exchanger, the temperatures of the reformate and cathode streams converge to nearly the same temperature at the outlet of the exchanger. Preferably, the heat exchanger is formed within an integrated component manifold (ICM) for a solid-oxide fuel cell assembly.

  13. Recuperator with microjet technology as a proposal for heat recovery from low-temperature sources

    NASA Astrophysics Data System (ADS)

    Wajs, Jan; Mikielewicz, Dariusz; Fornalik-Wajs, Elżbieta; Bajor, Michał

    2015-12-01

    A tendency to increase the importance of so-called dispersed generation, based on the local energy sources and the working systems utilizing both the fossil fuels and the renewable energy resources is observed nowadays. Generation of electricity on industrial or domestic scale together with production of heat can be obtained for example through employment of the ORC systems. It is mentioned in the EU directive 2012/27/EU for cogenerative production of heat and electricity. For such systems the crucial points are connected with the heat exchangers, which should be small in size but be able to transfer high heat fluxes. In presented paper the prototype microjet heat exchanger dedicated for heat recovery systems is introduced. Its novel construction is described together with the systematical experimental analysis of heat transfer and flow characteristics. Reported results showed high values of the overall heat transfer coefficient and slight increase in the pressure drop. The results of microjet heat exchanger were compared with the results of commercially available compact plate heat exchanger.

  14. 24 CFR 3280.702 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... means that portion of a refrigerated air cooling or (in the case of a heat pump) heating system which includes the refrigerant pump (compressor) and the external heat exchanger. Air conditioning evaporator section means a heat exchanger used to cool or (in the case of a heat pump) heat air for use in comfort...

  15. Study and development of a cryogenic heat exchanger for life support systems

    NASA Technical Reports Server (NTRS)

    Soliman, M. M.

    1973-01-01

    A prototype cryogenic heat exchanger for removal of waste heat from a spacecraft environmental control life support system was developed. The heat exchanger uses the heat sink capabilities of the cryogenic propellants and, hence, can operate over all mission phases from prelaunch to orbit, to post landing, with quiescent periods during orbit. A survey of candidate warm fluids resulted in the selection of E-2, a fluorocarbon compound, because of its low freezing point and high boiling point. The final design and testing of the heat exchanger was carried out, however, using Freon-21, which is similar to E-2 except for its low boiling point. This change was motivated by the desire for cost effectiveness of the experimental program. The transient performance of the heat exchanger was demonstrated by an analog simulation of the heat sink system. Under the realistic transient heat load conditions (20 sec ramp from minimum to maximum Freon-21 inlet temperature), the control system was able to maintain the warm fluid outlet temperature within + or - 3 F. For a 20-sec ramp from 0 F to -400 F in the hydrogen inlet temperature, at maximum heat load, the warm fluid outlet temperature was maintained within + or - 7 F.

  16. Effect of Tube Diameter on The Design of Heat Exchanger in Solar Drying system

    NASA Astrophysics Data System (ADS)

    Husham Abdulmalek, Shaymaa; Khalaji Assadi, Morteza; Al-Kayiem, Hussain H.; Gitan, Ali Ahmed

    2018-03-01

    The drying of agriculture product consumes a huge fossil fuel rates that demand to find an alternative source of sustainable environmental friendly energy such as solar energy. This work presents the difference between using solar heat source and electrical heater in terms of design aspect. A circular-finned tube bank heat exchanger is considered against an electrical heater used as a heat generator to regenerate silica gel in solar assisted desiccant drying system. The impact of tube diameter on the heat transfer area was investigated for both the heat exchanger and the electrical heater. The fin performance was investigated by determining fin effectiveness and fin efficiency. A mathematical model was developed using MATLAB to describe the forced convection heat transfer between hot water supplied by evacuated solar collector with 70 °C and ambient air flow over heat exchanger finned tubes. The results revealed that the increasing of tube diameter augments the heat transfer area of both heat exchanger and electrical heater. The highest of fin efficiency was around 0.745 and the lowest was around 0.687 while the fin effectiveness was found to be around 0.998.

  17. Microchannel crossflow fluid heat exchanger and method for its fabrication

    DOEpatents

    Swift, G.W.; Migliori, A.; Wheatley, J.C.

    1985-05-14

    A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance. 9 figs.

  18. New type of heating system for clothes dryer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Itoh, K.; Itoh, C.

    1995-12-01

    The basic technology to improve serviceability and reliability of the electric clothes dryer relies on the heater and heat exchanger. This paper describes the status of stress analysis and the evaluation of reliability for semiconductors consisting of BaTiO{sub 3} for disk-type heat exchangers/heaters with honeycomb openings. If the authors could keep the Curie temperature of the semiconductor lower than the ignition temperature of clothing during the drying cycle, installation of two legally limited thermostats would no longer be required and reliability of the control system could be further improved due to its simplified structure. The heater can be made moremore » compact by designing a honeycomb-type heater/heat exchangers but the structural requirements for the heat exchanger and the heater would conflict. An approximate solution to heater/heat exchanger stress is being sought as a thermal stress issue for an equivalent solid compound disc.« less

  19. Comparison of Analytical and Experimental Effectiveness of Four-Row Plate-Fin-Tube Heat Exchangers with Water, R-22, and R-410A

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baxter, V.D.; Chen, T.D.; Conklin, J.C.

    1998-11-15

    The analytical solutions of heat exchanger effectiveness for four-row crcmilow, cross-countertlow and cross-paralleltlow have been derived in the recent study. The main objective of this study is to investigate the etlkct of heat exchawger tlow conllguration on thermal performance with refrigerant mixtures. Difference of heat exchanger effectiveness for all flow arrangements relative to an analytical many-row solution has been analyzed. A comparison of four-row cross cou~ltet-ilow heat exchanger effectiveness between analytical solutions and experimental data with water, R-22, and R-4 10A is presented.

  20. NUCLEAR POWER INSTALLATIONS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bell, F.R.

    1962-12-01

    An arrangement is described for nuclear power plants including a reactor and at least one heat exchanger having primary and secondary circuits through which are passed heat-conveying fluids. Pressure-resisting walls about the heat exchangers and the reactor are either integral with or rigidly connected to one another. The heat exchangers are arranged so that their casings tend to shield withdrawn control rods from damage by radiation. (R.J.S.)

  1. Microscale Regenerative Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2006-01-01

    The device described herein is designed primarily for use as a regenerative heat exchanger in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat exchanger (sometimes called, simply, a "regenerator" in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle.

  2. 40 CFR 63.1090 - What reports must I submit?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Recordkeeping and Reporting Requirements for Heat Exchange Systems § 63.1090 What reports must I submit? If you delay repair for your heat exchange system, you must report the delay of repair in the...

  3. 40 CFR 63.1090 - What reports must I submit?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Recordkeeping and Reporting Requirements for Heat Exchange Systems § 63.1090 What reports must I submit? If you delay repair for your heat exchange system, you must report the delay of repair in the...

  4. 40 CFR 63.1090 - What reports must I submit?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Recordkeeping and Reporting Requirements for Heat Exchange Systems § 63.1090 What reports must I submit? If you delay repair for your heat exchange system, you must report the delay of repair in the...

  5. 40 CFR 63.1090 - What reports must I submit?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Recordkeeping and Reporting Requirements for Heat Exchange Systems § 63.1090 What reports must I submit? If you delay repair for your heat exchange system, you must report the delay of repair in the...

  6. 40 CFR 63.1090 - What reports must I submit?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Recordkeeping and Reporting Requirements for Heat Exchange Systems § 63.1090 What reports must I submit? If you delay repair for your heat exchange system, you must report the delay of repair in the...

  7. Thermoacoustic refrigerators and engines comprising cascading stirling thermodynamic units

    DOEpatents

    Backhaus, Scott; Swift, Greg

    2013-06-25

    The present invention includes a thermoacoustic assembly and method for improved efficiency. The assembly has a first stage Stirling thermal unit comprising a main ambient heat exchanger, a regenerator and at least one additional heat exchanger. The first stage Stirling thermal unit is serially coupled to a first end of a quarter wavelength long coupling tube. A second stage Stirling thermal unit comprising a main ambient heat exchanger, a regenerator, and at least one additional heat exchanger, is serially coupled to a second end of the quarter wavelength long coupling tube.

  8. Heat exchanger and water tank arrangement for passive cooling system

    DOEpatents

    Gillett, J.E.; Johnson, F.T.; Orr, R.S.; Schulz, T.L.

    1993-11-30

    A water storage tank in the coolant water loop of a nuclear reactor contains a tubular heat exchanger. The heat exchanger has tube sheets mounted to the tank connections so that the tube sheets and tubes may be readily inspected and repaired. Preferably, the tubes extend from the tube sheets on a square pitch and then on a rectangular pitch there between. Also, the heat exchanger is supported by a frame so that the tank wall is not required to support all of its weight. 6 figures.

  9. Study of transient behavior of finned coil heat exchangers

    NASA Technical Reports Server (NTRS)

    Rooke, S. P.; Elissa, M. G.

    1993-01-01

    The status of research on the transient behavior of finned coil cross-flow heat exchangers using single phase fluids is reviewed. Applications with available analytical or numerical solutions are discussed. Investigation of water-to-air type cross-flow finned tube heat exchangers is examined through the use of simplified governing equations and an up-wind finite difference scheme. The degenerate case of zero air-side capacitance rate is compared with available exact solution. Generalization of the numerical model is discussed for application to multi-row multi-circuit heat exchangers.

  10. Performance of heat exchangers used in whole body perfusion circuits.

    PubMed Central

    Bethune, D W; Gill, R D; Wheeldon, D R

    1975-01-01

    The performance of some commonly used heat exchangers has been investigated with particular reference to the effect of varying the water flow. The results demonstrate that there is considerable variation in the performance of most units when the water flow is changed. It is suggested that more information should be provided by the manufacturers of heat exchangers and that there should be a supply of water in cardiothoracic theatres at a sufficient pressure to allow the full performance of the heat exchangers to be realized. PMID:1198400

  11. Various methods to improve heat transfer in exchangers

    NASA Astrophysics Data System (ADS)

    Pavel, Zitek; Vaclav, Valenta

    2015-05-01

    The University of West Bohemia in Pilsen (Department of Power System Engineering) is working on the selection of effective heat exchangers. Conventional shell and tube heat exchangers use simple segmental baffles. It can be replaced by helical baffles, which increase the heat transfer efficiency and reduce pressure losses. Their usage is demonstrated in the primary circuit of IV. generation MSR (Molten Salt Reactors). For high-temperature reactors we consider the use of compact desk heat exchangers, which are small, which allows the integral configuration of reactor. We design them from graphite composites, which allow up to 1000°C and are usable as exchangers: salt-salt or salt-acid (e.g. for the hydrogen production). In the paper there are shown thermo-physical properties of salts, material properties and principles of calculations.

  12. The influence of flow modification on air and PCM temperatures in an accumulative heat exchanger

    NASA Astrophysics Data System (ADS)

    Borcuch, Marcin; Musiał, Michał; Sztekler, Karol; Kalawa, Wojciech; Gumuła, Stanisław; Stefański, Sebastian

    2018-06-01

    The paper presents the influence of flow modification on the operation of an accumulative heat exchanger. This device can be used as a regenerator in ventilation and air supply systems. A heat exchanger uses ceresine (a mixture of paraffins) as a phase change material (PCM). The aim of this research was to determine the effect of flow modification on temperature distribution and pressure drops in the device. The introduction contains a short description of the test stand used, including the accumulative heat exchanger, the guide vanes, and the locations of measurement and control equipment. We found that additional objects limited vortex structures, increased the inside temperature, and dropped the pressure along the heat exchanger. Guidelines for further research are proposed and briefly discussed.

  13. Recovery of Water from Boiler Flue Gas

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Edward Levy; Harun Bilirgen; Kwangkook Jeong

    2008-09-30

    This project dealt with use of condensing heat exchangers to recover water vapor from flue gas at coal-fired power plants. Pilot-scale heat transfer tests were performed to determine the relationship between flue gas moisture concentration, heat exchanger design and operating conditions, and water vapor condensation rate. The tests also determined the extent to which the condensation processes for water and acid vapors in flue gas can be made to occur separately in different heat transfer sections. The results showed flue gas water vapor condensed in the low temperature region of the heat exchanger system, with water capture efficiencies depending stronglymore » on flue gas moisture content, cooling water inlet temperature, heat exchanger design and flue gas and cooling water flow rates. Sulfuric acid vapor condensed in both the high temperature and low temperature regions of the heat transfer apparatus, while hydrochloric and nitric acid vapors condensed with the water vapor in the low temperature region. Measurements made of flue gas mercury concentrations upstream and downstream of the heat exchangers showed a significant reduction in flue gas mercury concentration within the heat exchangers. A theoretical heat and mass transfer model was developed for predicting rates of heat transfer and water vapor condensation and comparisons were made with pilot scale measurements. Analyses were also carried out to estimate how much flue gas moisture it would be practical to recover from boiler flue gas and the magnitude of the heat rate improvements which could be made by recovering sensible and latent heat from flue gas.« less

  14. Numerical modeling and analytical modeling of cryogenic carbon capture in a de-sublimating heat exchanger

    NASA Astrophysics Data System (ADS)

    Yu, Zhitao; Miller, Franklin; Pfotenhauer, John M.

    2017-12-01

    Both a numerical and analytical model of the heat and mass transfer processes in a CO2, N2 mixture gas de-sublimating cross-flow finned duct heat exchanger system is developed to predict the heat transferred from a mixture gas to liquid nitrogen and the de-sublimating rate of CO2 in the mixture gas. The mixture gas outlet temperature, liquid nitrogen outlet temperature, CO2 mole fraction, temperature distribution and de-sublimating rate of CO2 through the whole heat exchanger was computed using both the numerical and analytic model. The numerical model is built using EES [1] (engineering equation solver). According to the simulation, a cross-flow finned duct heat exchanger can be designed and fabricated to validate the models. The performance of the heat exchanger is evaluated as functions of dimensionless variables, such as the ratio of the mass flow rate of liquid nitrogen to the mass flow rate of inlet flue gas.

  15. Integrated hydrocarbon reforming system and controls

    DOEpatents

    Clawson, Lawrence G.; Dorson, Matthew H.; Mitchell, William L.; Nowicki, Brian J.; Thijssen, Johannes; Davis, Robert; Papile, Christopher; Rumsey, Jennifer W.; Longo, Nathan; Cross, III, James C.; Rizzo, Vincent; Kleeburg, Gunther; Rindone, Michael; Block, Stephen G.; Sun, Maria; Morriseau, Brian D.; Hagan, Mark R.; Bowers, Brian

    2003-11-04

    A hydrocarbon reformer system including a first reactor configured to generate hydrogen-rich reformate by carrying out at least one of a non-catalytic thermal partial oxidation, a catalytic partial oxidation, a steam reforming, and any combinations thereof, a second reactor in fluid communication with the first reactor to receive the hydrogen-rich reformate, and having a catalyst for promoting a water gas shift reaction in the hydrogen-rich reformate, and a heat exchanger having a first mass of two-phase water therein and configured to exchange heat between the two-phase water and the hydrogen-rich reformate in the second reactor, the heat exchanger being in fluid communication with the first reactor so as to supply steam to the first reactor as a reactant is disclosed. The disclosed reformer includes an auxiliary reactor configured to generate heated water/steam and being in fluid communication with the heat exchanger of the second reactor to supply the heated water/steam to the heat exchanger.

  16. Inverse heat transfer problem in digital temperature control in plate fin and tube heat exchangers

    NASA Astrophysics Data System (ADS)

    Taler, Dawid; Sury, Adam

    2011-12-01

    The aim of the paper is a steady-state inverse heat transfer problem for plate-fin and tube heat exchangers. The objective of the process control is to adjust the number of fan revolutions per minute so that the water temperature at the heat exchanger outlet is equal to a preset value. Two control techniques were developed. The first is based on the presented mathematical model of the heat exchanger while the second is a digital proportional-integral-derivative (PID) control. The first procedure is very stable. The digital PID controller becomes unstable if the water volumetric flow rate changes significantly. The developed techniques were implemented in digital control system of the water exit temperature in a plate fin and tube heat exchanger. The measured exit temperature of the water was very close to the set value of the temperature if the first method was used. The experiments showed that the PID controller works also well but becomes frequently unstable.

  17. Nuclear code case development of printed-circuit heat exchangers with thermal and mechanical performance testing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aakre, Shaun R.; Jentz, Ian W.; Anderson, Mark H.

    The U.S. Department of Energy has agreed to fund a three-year integrated research project to close technical gaps involved with compact heat exchangers to be used in nuclear applications. This paper introduces the goals of the project, the research institutions, and industrial partners working in collaboration to develop a draft Boiler and Pressure Vessel Code Case for this technology. Heat exchanger testing, as well as non-destructive and destructive evaluation, will be performed by researchers across the country to understand the performance of compact heat exchangers. Testing will be performed using coolants and conditions proposed for Gen IV Reactor designs. Preliminarymore » observations of the mechanical failure mechanisms of the heat exchangers using destructive and non-destructive methods is presented. Unit-cell finite element models assembled to help predict the mechanical behavior of these high-temperature components are discussed as well. Performance testing methodology is laid out in this paper along with preliminary modeling results, an introduction to x-ray and neutron inspection techniques, and results from a recent pressurization test of a printed-circuit heat exchanger. The operational and quality assurance knowledge gained from these models and validation tests will be useful to developers of supercritical CO 2 systems, which commonly employ printed-circuit heat exchangers.« less

  18. Measured performance of the heat exchanger in the NASA icing research tunnel under severe icing and dry-air conditions

    NASA Technical Reports Server (NTRS)

    Olsen, W.; Vanfossen, J.; Nussle, R.

    1987-01-01

    Measurements were made of the pressure drop and thermal perfomance of the unique refrigeration heat exchanger in the NASA Lewis Icing Research Tunnel (IRT) under severe icing and frosting conditions and also with dry air. This data will be useful to those planning to use or extend the capability of the IRT and other icing facilities (e.g., the Altitude Wind Tunnel-AWT). The IRT heat exchanger and refrigeration system is able to cool air passing through the test section down to at least a total temperature of -30 C (well below icing requirements), and usually up to -2 C. The system maintains a uniform temperature across the test section at all airspeeds, which is more difficult and time consuming at low airspeeds, at high temperatures, and on hot, humid days when the cooling towers are less efficient. The very small surfaces of the heat exchanger prevent any icing cloud droplets from passing through it and going through the tests section again. The IRT heat exchanger was originally designed not to be adversely affected by severe icing. During a worst-case icing test the heat exchanger iced up enough so that the temperature uniformaity was no worse than about +/- 1 deg C. The conclusion is that the heat exchanger design performs well.

  19. Frostless heat pump having thermal expansion valves

    DOEpatents

    Chen, Fang C [Knoxville, TN; Mei, Viung C [Oak Ridge, TN

    2002-10-22

    A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.

  20. Enhanced two phase flow in heat transfer systems

    DOEpatents

    Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

    2013-12-03

    A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

  1. Reconsideration of data and correlations for plate finned-tube heat exchangers

    NASA Astrophysics Data System (ADS)

    Otović, Milena; Mihailović, Miloš; Genić, Srbislav; Jaćimović, Branislav; Milovančević, Uroš; Marković, Saša

    2018-04-01

    This paper deals with heat exchangers having plain finned tubes in staggered (triangular) pattern. The objective of this paper is to provide the heat transfer and friction factor correlation which can be used in engineering practice. For this purpose, the experimental data of several (most cited) authors who deal with this type of heat exchangers are used. The new correlations are established to predict the air-side heat transfer coefficient and friction factor as a function of the Reynolds number and geometric variables of the heat exchanger - tube diameter, tube pitch, fin spacing, tube rows, etc. In those correlations the characteristic dimension in Reynolds number is calculated by using the new parameter - volumetric porosity. Also, there are given the errors of those correlations.

  2. Thermal-powered reciprocating pump

    NASA Technical Reports Server (NTRS)

    Sabelman, E. E.

    1972-01-01

    Waste heat from radioisotope thermal generators in spacecraft is transported to keep instruments warm by two-cylinder reciprocating pump powered by energy from warm heat exchange fluid. Each cylinder has thermally nonconductive piston, heat exchange coil, and heat sink surface.

  3. Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger

    DOEpatents

    Berry, G.F.; Minkov, V.; Petrick, M.

    1981-11-02

    A magnetohydrodynamic (MHD) power generating system is described in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.

  4. Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger

    DOEpatents

    Berry, Gregory F.; Minkov, Vladimir; Petrick, Michael

    1988-01-05

    A magnetohydrodynamic (MHD) power generating system in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.

  5. Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger

    DOEpatents

    Berry, Gregory F.; Minkov, Vladimir; Petrick, Michael

    1988-01-01

    A magnetohydrodynamic (MHD) power generating system in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.

  6. Super energy saver heat pump with dynamic hybrid phase change material

    DOEpatents

    Ally, Moonis Raza [Oak Ridge, TN; Tomlinson, John Jager [Knoxville, TN; Rice, Clifford Keith [Clinton, TN

    2010-07-20

    A heat pump has a refrigerant loop, a compressor in fluid communication with the refrigerant loop, at least one indoor heat exchanger in fluid communication with the refrigerant loop, and at least one outdoor heat exchanger in fluid communication with the refrigerant loop. The at least one outdoor heat exchanger has a phase change material in thermal communication with the refrigerant loop and in fluid communication with an outdoor environment. Other systems, devices, and methods are described.

  7. Matrix heat exchanger including a liquid, thermal couplant

    DOEpatents

    Fewell, Thomas E.; Ward, Charles T.

    1976-01-01

    A tube-to-tube heat exchanger is disclosed with a thermally conductive matrix between and around the tubes to define annuli between the tubes and matrix. The annuli are filled to a level with a molten metal or alloy to provide a conductive heat transfer path from one tube through the matrix to the second tube. A matrix heat exchanger of this type is particularly useful for heat transfer between fluids which would react should one leak into the second.

  8. Heat exchanger device and method for heat removal or transfer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koplow, Jeffrey P

    2015-03-24

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  9. Heat exchanger device and method for heat removal or transfer

    DOEpatents

    Koplow, Jeffrey P [San Ramon, CA

    2012-07-24

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  10. Heat exchanger device and method for heat removal or transfer

    DOEpatents

    Koplow, Jeffrey P

    2013-12-10

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  11. Heat exchanger device and method for heat removal or transfer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koplow, Jeffrey P.

    2015-12-08

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  12. Heat pump system with selective space cooling

    DOEpatents

    Pendergrass, J.C.

    1997-05-13

    A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

  13. Heat pump system with selective space cooling

    DOEpatents

    Pendergrass, Joseph C.

    1997-01-01

    A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve.

  14. Cooperation of Horizontal Ground Heat Exchanger with the Ventilation Unit During Summer - Case Study

    NASA Astrophysics Data System (ADS)

    Romańska-Zapała, Anna; Furtak, Marcin; Dechnik, Mirosław

    2017-10-01

    Renewable energy sources are used in the modern energy-efficient buildings to improve their energy balance. One of them is used in the mechanical ventilation system ground air heat exchanger (earth-air heat exchanger - EAHX). This solution, right after heat recovery from exhaust air (recuperation), allows the reduction in the energy needed to obtain the desired temperature of supply air. The article presents the results of "in situ" measurements of pipe ground air heat exchanger cooperating with the air handling unit, supporting cooling the building in the summer season, in Polish climatic conditions. The laboratory consists of a ventilation unit intake - exhaust with rotor for which the source of fresh air is the air intake wall and two air intakes field cooperating with the tube with ground air heat exchangers. Selection of the source of fresh air is performed using sprocket with actuators. This system is part of the ventilation system of the Malopolska Laboratory of Energy-Efficient Building (MLBE) building of Cracow University of Technology. The measuring system are, among others, the sensors of parameters of air inlets and outlets of the heat exchanger channels EAHX and weather station that senses the local weather conditions. The measurement data are recorded and archived by the integrated process control system in the building of MLBE. During the study measurements of operating parameters of the ventilation unit cooperating with the selected source of fresh air were performed. Two cases of operation of the system: using EAHX heat exchanger and without it, were analyzed. Potentially the use of ground air heat exchanger in the mechanical ventilation system can reduce the energy demand for heating or cooling rooms by the pre-adjustment of the supply air temperature. Considering the results can be concluded that the continuous use of these exchangers is not optimal. This relationship is appropriate not only on an annual basis for the transitional periods (spring and autumn), but also in individual days in the potentially most favorable periods of work exchanger (summer and winter). Inappropriate operation of the heat exchanger, will lead to a temporary increase in energy consumption for the preparation of the desired air temperature, relative to the fresh air unit which is non-pretreated. For optimal energy system operation: exchanger EAHX - air handling unit, to preserve the most favourable parameters of inlet air to handling unit, there is a need to dynamically adjust the source of fresh air, depending on changing external conditions and the required outlet temperature of central unit (temperature of air forced to the rooms).

  15. Material Studies Related to the Use of NaK Heat Exchangers Coupled to Stirling Heater Heads

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Bowman, Cheryl L.; Geng, Steven M.; Robbie, Malcolm G.

    2011-01-01

    NASA has been supporting design studies and technology development that could provide power to an outpost on the Moon, Mars, or an asteroid. Technology development efforts have included fabrication and evaluation of components used in a Stirling engine power conversion system. Destructive material evaluation was performed on a NaK shell heat exchanger that was developed by the NASA Glenn Research Center (GRC) and integrated with a commercial 1 kWe Stirling convertor from Sunpower Incorporated. The NaK Stirling test demonstrated Stirling convertor electrical power generation using a pumped liquid metal heat source under thermal conditions that represent the heat exchanger liquid metal loop in a Fission Power Systems (FPS) reactor. The convertors were operated for a total test time of 66 hr at a maximum temperature of 823 K. After the test was completed and NaK removed, the heat exchanger assembly was sectioned to evaluate any material interactions with the flowing liquid metal. Several dissimilar-metal braze joint options, crucial for the heat exchanger transfer path, were also investigated. A comprehensive investigation was completed and lessons learned for future heat exchanger development efforts are discussed.

  16. Phase Change Material Heat Exchanger Life Test

    NASA Technical Reports Server (NTRS)

    Lillibridge, Sean; Stephan, Ryan

    2009-01-01

    Low Lunar Orbit (LLO) poses unique thermal challenges for the orbiting space craft, particularly regarding the performance of the radiators. The IR environment of the space craft varies drastically from the light side to the dark side of the moon. The result is a situation where a radiator sized for the maximal heat load in the most adverse situation is subject to freezing on the dark side of the orbit. One solution to this problem is to implement Phase Change Material (PCM) Heat Exchangers. PCM Heat Exchangers act as a "thermal capacitor," storing thermal energy when there is too much being produced by the space craft to reject to space, and then feeding that energy back into the thermal loop when conditions are more favorable. Because they do not use an expendable resource, such as the feed water used by sublimators and evaporators, PCM Heat Exchangers are ideal for long duration LLO missions. In order to validate the performance of PCM Heat Exchangers, a life test is being conducted on four n-Pentadecane, carbon filament heat exchangers. Fluid loop performance, repeatability, and measurement of performance degradation over 2500 melt-freeze cycles will be performed.

  17. Heat transfer and pressure drop performance of a finned-tube heat exchanger proposed for use in the NASA Lewis Altitude Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Vanfossen, G. J.

    1985-01-01

    A segment of the heat exchanger proposed for use in the NASA Lewis Altitude Wind Tunnel (AWT) facility has been tested under dry and icing conditions. The heat exchanger has the largest pressure drop of any component in the AWT loop. It is therefore critical that its performance be known at all conditions before the final design of the AWT is complete. The heat exchanger segment is tested in the NASA Lewis Icing Research Tunnel (IRT) in order to provide an icing cloud environment similar to what will be encountered in the AWT. Dry heat transfer and pressure drop data are obtained and compared to correlations available in the literature. The effects of icing sprays on heat transfer and pressure drop are also investigated.

  18. Rankine cycle waste heat recovery system

    DOEpatents

    Ernst, Timothy C.; Nelson, Christopher R.

    2015-09-22

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

  19. Extended range heat pump system and centrifugal compressor for use therewith

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shoemaker, J.F.

    1988-04-26

    Improvements in heat pump systems having indoor and outdoor heat exchangers and at least two compressors for supplying a refrigerant medium under pressure thereto, and means for circulating the medium through the heat exchangers, the improvement is described comprising a selector valve associated with each of the compressors. The selector valves provide that any combination and any one or more of the compressors can be selected for operation, each of the selector valves having a first operating condition placing the associated compressor in series with the heat exchangers and a second operating condition whereby the associated compressor is bypassed, whenmore » the selector valves for at least two of the compressors are simultaneously in their first positions a flow path is established through the associated compressors and through the heat exchangers all in series, a two position changeover valve and associated conduit means. The changeover valve has a first position wherein at least one of the compressors is connected in series with the first and second heat exchangers to produce flow of the medium in one direction therethrough and a second position whereby at least one compressor is connected to produce flow of the medium in the opposite direction through the heat exchangers.« less

  20. Heat transfer analysis of underground U-type heat exchanger of ground source heat pump system.

    PubMed

    Pei, Guihong; Zhang, Liyin

    2016-01-01

    Ground source heat pumps is a building energy conservation technique. The underground buried pipe heat exchanging system of a ground source heat pump (GSHP) is the basis for the normal operation of an entire heat pump system. Computational-fluid-dynamics (CFD) numerical simulation software, ANSYS-FLUENT17.0 have been performed the calculations under the working conditions of a continuous and intermittent operation over 7 days on a GSHP with a single-well, single-U and double-U heat exchanger and the impact of single-U and double-U buried heat pipes on the surrounding rock-soil temperature field and the impact of intermittent operation and continuous operation on the outlet water temperature. The influence on the rock-soil temperature is approximately 13 % higher for the double-U heat exchanger than that of the single-U heat exchanger. The extracted energy of the intermittent operation is 36.44 kw·h higher than that of the continuous mode, although the running time is lower than that of continuous mode, over the course of 7 days. The thermal interference loss and quantity of heat exchanged for unit well depths at steady-state condition of 2.5 De, 3 De, 4 De, 4.5 De, 5 De, 5.5 De and 6 De of sidetube spacing are detailed in this work. The simulation results of seven working conditions are compared. It is recommended that the side-tube spacing of double-U underground pipes shall be greater than or equal to five times of outer diameter (borehole diameter: 180 mm).

  1. Multi-stage flash degaser

    DOEpatents

    Rapier, P.M.

    1980-06-26

    A multi-stage flash degaser is incorporated in an energy conversion system having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger in order that the heat exchanger and a turbine and condenser of the system can operate at optimal efficiency.

  2. 40 CFR 90.421 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Volume Sampler (PDP-CVS) system with a heat exchanger, or a Critical Flow Venturi—Constant Volume Sampler (CFV-CVS) system with CFV sample probes and/or a heat exchanger or electronic flow compensation. Figure... sampling point. (ii) For the CFV-CVS, either a heat exchanger or electronic flow compensation is required...

  3. 40 CFR 91.421 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Pump—Constant Volume Sampler (PDP-CVS) system with a heat exchanger, or a Critical Flow Venturi—Constant Volume Sampler (CFV-CVS) system with CVS sample probes and/or a heat exchanger or electronic flow... sampling point. (ii) For the CFV-CVS, either a heat exchanger or electronic flow compensation is required...

  4. 40 CFR 91.421 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Pump—Constant Volume Sampler (PDP-CVS) system with a heat exchanger, or a Critical Flow Venturi—Constant Volume Sampler (CFV-CVS) system with CVS sample probes and/or a heat exchanger or electronic flow... sampling point. (ii) For the CFV-CVS, either a heat exchanger or electronic flow compensation is required...

  5. 40 CFR 90.421 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Volume Sampler (PDP-CVS) system with a heat exchanger, or a Critical Flow Venturi—Constant Volume Sampler (CFV-CVS) system with CFV sample probes and/or a heat exchanger or electronic flow compensation. Figure... sampling point. (ii) For the CFV-CVS, either a heat exchanger or electronic flow compensation is required...

  6. 40 CFR 91.421 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Pump—Constant Volume Sampler (PDP-CVS) system with a heat exchanger, or a Critical Flow Venturi—Constant Volume Sampler (CFV-CVS) system with CVS sample probes and/or a heat exchanger or electronic flow... sampling point. (ii) For the CFV-CVS, either a heat exchanger or electronic flow compensation is required...

  7. 40 CFR 90.421 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Volume Sampler (PDP-CVS) system with a heat exchanger, or a Critical Flow Venturi—Constant Volume Sampler (CFV-CVS) system with CFV sample probes and/or a heat exchanger or electronic flow compensation. Figure... sampling point. (ii) For the CFV-CVS, either a heat exchanger or electronic flow compensation is required...

  8. 40 CFR 63.11495 - What are the management practices and other requirements?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... repairs, and, if applicable, the reasons for any delay in repair. (b) Small heat exchange systems. For each heat exchange system subject to this subpart with a cooling water flow rate less than 8,000... in accordance with a heat exchange system inspection plan. The plan must describe the inspections to...

  9. 40 CFR 63.1087 - What actions must I take if a leak is detected?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Repair Requirements for Heat Exchange Systems § 63.1087 What actions must I take if a... within 7 calendar days of the repair or startup, whichever is later, to confirm that the heat exchange...

  10. 40 CFR 63.1087 - What actions must I take if a leak is detected?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Repair Requirements for Heat Exchange Systems § 63.1087 What actions must I take if a... within 7 calendar days of the repair or startup, whichever is later, to confirm that the heat exchange...

  11. 40 CFR 63.1087 - What actions must I take if a leak is detected?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Repair Requirements for Heat Exchange Systems § 63.1087 What actions must I take if a... within 7 calender days of the repair or startup, whichever is later, to confirm that the heat exchange...

  12. 40 CFR 63.1087 - What actions must I take if a leak is detected?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Repair Requirements for Heat Exchange Systems § 63.1087 What actions must I take if a... within 7 calendar days of the repair or startup, whichever is later, to confirm that the heat exchange...

  13. 76 FR 42052 - National Emission Standards for Hazardous Air Pollutants From Petroleum Refineries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-18

    ... under CAA sections 112(d)(2) and (3) for heat exchange systems, which the EPA had not addressed in the... rule addressed residual risk for all Refinery MACT 1 sources, including heat exchange systems. Third... continue to make improvements in emissions reductions, and the heat exchange system standards will reduce...

  14. 40 CFR 63.1087 - What actions must I take if a leak is detected?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations Repair Requirements for Heat Exchange Systems § 63.1087 What actions must I take if a... within 7 calender days of the repair or startup, whichever is later, to confirm that the heat exchange...

  15. 40 CFR 63.11495 - What are the management practices and other requirements?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... repairs, and, if applicable, the reasons for any delay in repair. (b) Small heat exchange systems. For each heat exchange system subject to this subpart with a cooling water flow rate less than 8,000... in accordance with a heat exchange system inspection plan. The plan must describe the inspections to...

  16. Heat Exchanger Lab for Chemical Engineering Undergraduates

    ERIC Educational Resources Information Center

    Rajala, Jonathan W.; Evans, Edward A.; Chase, George G.

    2015-01-01

    Third year chemical engineering undergraduate students at The University of Akron designed and fabricated a heat exchanger for a stirred tank as part of a Chemical Engineering Laboratory course. The heat exchanger portion of this course was three weeks of the fifteen week long semester. Students applied concepts of scale-up and dimensional…

  17. Numerical calculation of a sea water heta exchanger using Simulink softwear

    NASA Astrophysics Data System (ADS)

    Preda, A.; Popescu, L. L.; Popescu, R. S.

    2017-08-01

    To highlight the heat exchange taking place between seawater as primary agent and the working fluid (water, glycol or Freon) as secondary agent, I have used the Simulink softwear in order to creat a new sequence for numerical calculation of heat exchanging. For optimum heat transfer we opted for a counter movement. The model developed to view the dynamic behavior of the exchanger consists of four interconnected levelsess. In the simulations was found that a finer mesh of the whole exchanger lead to results much closer to reality. There have been various models meshing, starting from a single cell and then advancing noticed an improvement in resultsSimulations were made in both the summer and the winter, using as a secondary agent process water and glycol solution. Studying heat transfer that occurs in the primary exchanger of a heat pump, having the primary fluid sea water with this program, we get the data plausible and worthy of consideration. Inserting into the program, the seasonal water temperatures of Black Sea water layers, we get a encouraging picture about storage capacity and heat transfer of sea water.

  18. Probable causes of damage of heat-exchange tubes of low-pressure-exchanges of PND-3 type and repair methods

    NASA Astrophysics Data System (ADS)

    Trifonov, N. N.; Esin, S. B.; Nikolaenkova, E. K.; Sukhorukov, Yu. G.; Svyatkin, F. A.; Sintsova, T. G.; Modestov, V. S.

    2017-08-01

    The structures of low-pressure heaters (LPH), which are installed at nuclear power plants with the K-1000-60/1500 type turbine plants are considered. It was revealed that only the PND-3 type low-pressure heaters have the damages of the heat exchange tubes. For a short operation life, the number of the damaged heat-exchange tubes of PND-3 is approximately 50 pcs for Kalinin NPP and 100-150 pcs for Balakovo NPP. The low-pressure heaters were manufactured at AO Ural Plant of Chemical Machine-Building "Uralkhimmash," OAO Taganrog Boiler-Making Works "Krasny Kotelshchik," and Vitkovice Machinery Group, but the damage nature of the heat-exchange tubes is identical for all PND-3. The damages occur in the place of passage of the heat exchange tubes through the first, the second, and the third partitions over the lower tube plate (the first path of the turbine condensate). Hydraulic shocks can be one of the possible causes of the damage of the heat-exchange tubes of PND-3. The analysis of the average thermal and dynamic loads of the tube systems of PND-1-PND-4 revealed that PND-3 by the thermal power are loaded 1.4-1.6 times and by the dynamic effects are loaded 1.8-2.0 times more than the remaining LPHs. Another possible cause of damage can be the cascaded drain of the separate into PND-4 and then through the drainage heat exchange into PND-3. An additional factor can be the structure of the condensate drainage unit. The advanced system of the heating steam flow and pumping scheme of the separate drain using the existing drainage pumps of PND-3 for K-1000-60/1500 turbine plants for Balakovo and Kalinin NPPs were proposed. The considered decisions make it possible to reduce the flow rate of the heating steam condensate from PND-3 into PND-4 and the speed of the heating steam in the tube space of PND-3 and eliminate the occurrence of hydraulic shocks and damages of the heat exchanger tubes.

  19. Study of Fluid Cooling Loop System in Chinese Manned Spacecraft

    NASA Astrophysics Data System (ADS)

    Jiang, Jun; Xu, Jiwan; Fan, Hanlin; Huang, Jiarong

    2002-01-01

    change. To solve the questions, a fluid cooling loop system must be applied to Chinese manned spacecraft besides other conventional thermal control methods, such as thermal control coatings, multiplayer insulation blankets, heat pipes, electro-heating adjustment temperature devices, and so on. The paper will introduce the thermal design of inner and outer fluid loop including their constitution and fundamental, etc. The capability of heat transportation and the accuracy of control temperature for the fluid loop will be evaluated and analyzed. To insure the air temperature of sealed cabins within 21+/-4, the inlet liquid temperature of condensing heat exchanger needs to be controlled within 9+/-2. To insure this, the inlet liquid temperature of middle heat exchanger needs to be controlled within 8+/-1.8. The inlet temperature point is controlled by a subsidiary loop adjusting: when the computer receives feedbacks of the deviation and the variety rate of deviation from the controlled temperature point. It drives the temperature control valve to adjust the flow flux distribution between the main loop through radiator and the subsidiary loop which isn't through radiator to control the temperature of the mixed fluid within 8+/-1.8. The paper will also introduce thermal designs of key parts in the cooling loop, such as space radiators, heat exchangers and cooling plates. Thermal simulated tests on the ground and flight tests have been performed to verify correctness of thermal designs. rational and the loop system works order. It realizes the circulation of absorbing heat dissipation to the loop and transferring it to radiator then radiating it to space. (2) loop control system controls inlet temperature of middle heat exchanger within 8+/-1.8 under various thermal cases. Thermal design of the middle heat exchanger insures inlet temperature of condensing heat within 9+/-2. Thereby, the air temperature of sealed cabins is controlled within about 21+/-4 accurately. (3) The thermal designs of the key heat exchanging parts (such as radiator, heat exchangers and cooling plates) in the cooling loop are rational and effective, they meet the requirements of heat exchanging and assure the entire system work order.

  20. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1996-12-03

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

  1. Rotary magnetic heat pump

    DOEpatents

    Kirol, Lance D.

    1988-01-01

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  2. Rotary magnetic heat pump

    DOEpatents

    Kirol, L.D.

    1987-02-11

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  3. Thermal control system. [removing waste heat from industrial process spacecraft

    NASA Technical Reports Server (NTRS)

    Hewitt, D. R. (Inventor)

    1983-01-01

    The temperature of an exothermic process plant carried aboard an Earth orbiting spacecraft is regulated using a number of curved radiator panels accurately positioned in a circular arrangement to form an open receptacle. A module containing the process is insertable into the receptacle. Heat exchangers having broad exterior surfaces extending axially above the circumference of the module fit within arcuate spacings between adjacent radiator panels. Banks of variable conductance heat pipes partially embedded within and thermally coupled to the radiator panels extend across the spacings and are thermally coupled to broad exterior surfaces of the heat exchangers by flanges. Temperature sensors monitor the temperature of process fluid flowing from the module through the heat exchanges. Thermal conduction between the heat exchangers and the radiator panels is regulated by heating a control fluid within the heat pipes to vary the effective thermal length of the heat pipes in inverse proportion to changes in the temperature of the process fluid.

  4. Thermal performance of a prototype plate heat exchanger with minichannels under boiling conditions

    NASA Astrophysics Data System (ADS)

    Wajs, J.; Mikielewicz, D.; Fornalik-Wajs, E.

    2016-09-01

    To solve the problem and to meet the requirements of customers in the field of high heat fluxes transfer in compact units, a new design of plate heat exchanger with minichannels (minichannels PHE) was proposed. The aim was to construct a compact heat exchanger of high effectiveness for the purpose of household cogeneration ORC system. In this paper the experimental analysis of an assembled prototype of such compact heat exchanger was described. The attention was paid to its thermal performance and the heat transfer coefficients under the boiling conditions. Water and ethanol were chosen as working fluids. The maximal value of transferred heat flux was about 84 kW/m2, while of the overall heat transfer coefficient was about 4000 W/(m2K). Estimated values of heat transfer coefficient on the ethanol (boiling) side reached the level of 7500 W/(m2K). The results are promising in the light of future applications, for example in cogeneration ORC systems, however further systematic investigations are necessary.

  5. Experimental investigation of a reticulated porous alumina heat exchanger for high temperature gas heat recovery

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Banerjee, A; Chandran, RB; Davidson, JH

    2015-01-22

    The present study presents an experimental study of a prototype counter-flow heat exchanger designed to recover sensible heat from inert and reactive gases flowing through a high temperature solar reactor for splitting CO2. The tube-in-tube heat exchanger is comprised of two concentric alumina tubes, each filled with reticulated porous alumina with a nominal porosity of 80% and pore density of 5 pores per inch (ppi). The RPC provides high heat transfer surface area per unit volume (917 m(-1)) with low pressure drop. Measurements include the permeability, inertial coefficient, overall heat transfer coefficient, effectiveness and pressure drop. For laminar flow andmore » an inlet gas temperature of 1240 K, the overall heat transfer coefficients are 36-41 W m(-2) K-1. The measured performance is in good agreement with a prior CFD model of the heat exchanger. (C) 2014 Elsevier Ltd. All rights reserved.« less

  6. Devise of an exhaust gas heat exchanger for a thermal oil heater in a palm oil refinery plant

    NASA Astrophysics Data System (ADS)

    Chucherd, Panom; Kittisupakorn, Paisan

    2017-08-01

    This paper presents the devise of an exhaust gas heat exchanger for waste heat recovery of the exhausted flue gas of palm oil refinery plant. This waste heat can be recovered by installing an economizer to heat the feed water which can save the fuel consumption of the coal fired steam boiler and the outlet temperature of flue gas will be controlled in order to avoid the acid dew point temperature and protect the filter bag. The decrease of energy used leads to the reduction of CO2 emission. Two designed economizer studied in this paper are gas in tube and water in tube. The gas in tube exchanger refers to the shell and tube heat exchanger which the flue gas flows in tube; this designed exchanger is used in the existing unit. The new designed water in tube refers to the shell and tube heat exchanger which the water flows in the tube; this designed exchanger is proposed for new implementation. New economizer has the overall coefficient of heat transfer of 19.03 W/m2.K and the surface heat transfer area of 122 m2 in the optimized case. Experimental results show that it is feasible to install economizer in the exhaust flue gas system between the air preheater and the bag filter, which has slightly disadvantage effect in the system. The system can raise the feed water temperature from 40 to 104°C and flow rate 3.31 m3/h, the outlet temperature of flue gas is maintained about 130 °C.

  7. Development of a Direct Contact Heat Exchanger, Phase 1 Study Report

    NASA Technical Reports Server (NTRS)

    Manvi, R.

    1978-01-01

    Electric power generation from geothermal brine requires, first, bringing the hot brine to the surface and then converting the heat to electric power. Binary conversion schemes were proposed, with the heat transfer between the brine and the working organic fluid taking place in a conventional tube and shell heat exchanger. If the brine is heavily laden with dissolved solids, however, solids buildup on the heat exchanger surfaces leads to a considerable degree of fouling and an accompanying drop in performance is experienced. A possible solution to this problem is the use of a direct contact exchanger with the secondary fluid power cycle. The proposed concept involves the formation of fluid sheets and bells as heat angles. Results of a study concerning the fluid mechanics of such surfaces are given.

  8. Heat transfer and hydrodynamic analysis in an industrial circulating fluidized bed boiler

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Di Maggio, T.; Piedfer, O.; Jestin, L.

    In order to scale-up Circulating Fluidized Bed boilers (up to 600 MWe), Electricite de France has initiated a Research and Development program including: laboratory work on mock-up, numerical modeling and on-site tests in the 125 MWe CFB Emile Huchet plant. This paper is devoted to on-site measurements analysis in two main components of this industrial unit: the external fluidized bed heat exchangers and the backpass. This study particularly concerns hydrodynamics and heat transfer with the final target of developing a physical model of a CFB unit. The first part of this paper describes the specific instrumentation set up on externalmore » fluidized bed heat exchangers. The comparison between experimental data collected on these heat exchangers and the theoretical heat transfer models mainly used, shows a great difference about the value of the overall heat transfer coefficient. To explain this discrepancy, the particle flow pattern initially used in the thermal balance calculation is modified and a solid bypass is introduced. The analysis of the by-pass behavior, connected to the geometrical and operating parameters of each exchanger, confirms the particle flow pattern suggested. The second part of this paper shows an analysis of the specific measurements set up on the backpass to study heat transfer. The physical model of heat transfer used to assess the importance of each convection, radiation and conduction components is presented. This model allows one to assess the influence of heat exchangers design on heat transfer. Moreover, the analysis of heat transfer variations during sweeping cycles gives the amount of dust that is removed from the heat exchanger tubes. These results are used to evaluate the amount of power that can be recovered by optimizing both design and sweeping of the backpass.« less

  9. Counterflow Regolith Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Zubrin, Robert; Jonscher, Peter

    2013-01-01

    A problem exists in reducing the total heating power required to extract oxygen from lunar regolith. All such processes require heating a great deal of soil, and the heat energy is wasted if it cannot be recycled from processed material back into new material. The counterflow regolith heat exchanger (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat exchanger with internal and external augers attached to the inner rotating tube to move the regolith. Hot regolith in the outer tube is moved in one direction by a right-hand - ed auger, and the cool regolith in the inner tube is moved in the opposite direction by a left-handed auger attached to the inside of the rotating tube. In this counterflow arrangement, a large fraction of the heat from the expended regolith is transferred to the new regolith. The spent regolith leaves the heat exchanger close to the temperature of the cold new regolith, and the new regolith is pre-heated close to the initial temperature of the spent regolith. Using the CoRHE can reduce the heating requirement of a lunar ISRU system by 80%, reducing the total power consumption by a factor of two. The unique feature of this system is that it allows for counterflow heat exchange to occur between solids, instead of liquids or gases, as is commonly done. In addition, in variants of this concept, the hydrogen reduction can be made to occur within the counterflow heat exchanger itself, enabling a simplified lunar ISRU (in situ resource utilization) system with excellent energy economy and continuous nonbatch mode operation.

  10. A laboratory exercise using a physical model for demonstrating countercurrent heat exchange.

    PubMed

    Loudon, Catherine; Davis-Berg, Elizabeth C; Botz, Jason T

    2012-03-01

    A physical model was used in a laboratory exercise to teach students about countercurrent exchange mechanisms. Countercurrent exchange is the transport of heat or chemicals between fluids moving in opposite directions separated by a permeable barrier (such as blood within adjacent blood vessels flowing in opposite directions). Greater exchange of heat or chemicals between the fluids occurs when the flows are in opposite directions (countercurrent) than in the same direction (concurrent). When a vessel loops back on itself, countercurrent exchange can occur between the two arms of the loop, minimizing loss or uptake at the bend of the loop. Comprehension of the physical principles underlying countercurrent exchange helps students to understand how kidneys work and how modifications of a circulatory system can influence the movement of heat or chemicals to promote or minimize exchange and reinforces the concept that heat and chemicals move down their temperature or concentration gradients, respectively. One example of a well-documented countercurrent exchanger is the close arrangement of veins and arteries inside bird legs; therefore, the setup was arranged to mimic blood vessels inside a bird leg, using water flowing inside tubing as a physical proxy for blood flow within blood vessels.

  11. Heat exchanger using graphite foam

    DOEpatents

    Campagna, Michael Joseph; Callas, James John

    2012-09-25

    A heat exchanger is disclosed. The heat exchanger may have an inlet configured to receive a first fluid and an outlet configured to discharge the first fluid. The heat exchanger may further have at least one passageway configured to conduct the first fluid from the inlet to the outlet. The at least one passageway may be composed of a graphite foam and a layer of graphite material on the exterior of the graphite foam. The layer of graphite material may form at least a partial barrier between the first fluid and a second fluid external to the at least one passageway.

  12. Numerical investigation of forced convection of nano fluid flow in horizontal U-longitudinal finned tube heat exchanger

    NASA Astrophysics Data System (ADS)

    Qasim, S. M.; Sahar, A. F. A.; Firas, A. A.

    2015-11-01

    A numerical study has been carried out to investigate the heat transfer by laminar forced convection of nanofluid taking Titania (TiO2) and Alumina (Al2O3) as nanoparticles and the water as based fluid in a three dimensional plain and U-longitudinal finned tube heat exchanger. A Solid WORKS PREMIUM 2012 is used to draw the geometries of plain tube heat exchanger or U-longitudinal copper finned tube heat exchanger. Four U-longitudinal copper fins have 100 cm long, 3.8cm height and 1mm thickness are attached to a straight copper tube of 100 cm length, 2.2 cm inner diameter and 2.39 cm outer diameter. The governing equations which used as continuity, momentum and energy equations under assumptions are utilized to predict the flow field, temperature distribution, and heat transfer of the heat exchanger. The finite volume approach is used to obtain all the computational results using commercial ANSYS Fluent copy package 14.0 with assist of solid works and Gambit software program. The effect of various parameters on the performance of heat exchanger are investigated numerically such as Reynolds' number (ranging from 270 to 1900), volume consternation of nanoparticles (0.2%, 0.4%, 0.6%, 0.8%), type of nanoparticles, and mass flow rate of nanofluid in the hot region of heat exchanger. For 0.8% consternation of nanoparticles, heat transfer has significant enhancement in both nanofluids. It can be found about 7.3% for TiO2 and about 7.5% for Al2O3 compared with the water only as a working fluid.

  13. Performance of casting aluminum-silicon alloy condensing heating exchanger for gas-fired boiler

    NASA Astrophysics Data System (ADS)

    Cao, Weixue; Liu, Fengguo; You, Xue-yi

    2018-07-01

    Condensing gas boilers are widely used due to their high heat efficiency, which comes from their ability to use the recoverable sensible heat and latent heat in flue gas. The condensed water of the boiler exhaust has strong corrosion effect on the heat exchanger, which restricts the further application of the condensing gas boiler. In recent years, a casting aluminum-silicon alloy (CASA), which boasts good anti-corrosion properties, has been introduced to condensing hot water boilers. In this paper, the heat transfer performance, CO and NOx emission concentrations and CASA corrosion resistance of a heat exchanger are studied by an efficiency bench test of the gas-fired boiler. The experimental results are compared with heat exchangers produced by Honeywell and Beka. The results show that the excess air coefficient has a significant effect on the heat efficiency and CO and NOx emission of the CASA water heater. When the excess air coefficient of the CASA gas boiler is 1.3, the CO and NOx emission concentration of the flue gas satisfies the design requirements, and the heat efficiency of water heater is 90.8%. In addition, with the increase of heat load rate, the heat transfer coefficient of the heat exchanger and the heat efficiency of the water heater are increased. However, when the heat load rate is at 90%, the NOx emission in the exhaust gas is the highest. Furthermore, when the temperature of flue gas is below 57 °C, the condensation of water vapor occurs, and the pH of condensed water is in the 2.5 5.5 range. The study shows that CASA water heater has good corrosion resistance and a high heat efficiency of 88%. Compared with the heat exchangers produced by Honeywell and Beka, there is still much work to do in optimizing and improving the water heater.

  14. Performance of casting aluminum-silicon alloy condensing heating exchanger for gas-fired boiler

    NASA Astrophysics Data System (ADS)

    Cao, Weixue; Liu, Fengguo; You, Xue-yi

    2018-01-01

    Condensing gas boilers are widely used due to their high heat efficiency, which comes from their ability to use the recoverable sensible heat and latent heat in flue gas. The condensed water of the boiler exhaust has strong corrosion effect on the heat exchanger, which restricts the further application of the condensing gas boiler. In recent years, a casting aluminum-silicon alloy (CASA), which boasts good anti-corrosion properties, has been introduced to condensing hot water boilers. In this paper, the heat transfer performance, CO and NOx emission concentrations and CASA corrosion resistance of a heat exchanger are studied by an efficiency bench test of the gas-fired boiler. The experimental results are compared with heat exchangers produced by Honeywell and Beka. The results show that the excess air coefficient has a significant effect on the heat efficiency and CO and NOx emission of the CASA water heater. When the excess air coefficient of the CASA gas boiler is 1.3, the CO and NOx emission concentration of the flue gas satisfies the design requirements, and the heat efficiency of water heater is 90.8%. In addition, with the increase of heat load rate, the heat transfer coefficient of the heat exchanger and the heat efficiency of the water heater are increased. However, when the heat load rate is at 90%, the NOx emission in the exhaust gas is the highest. Furthermore, when the temperature of flue gas is below 57 °C, the condensation of water vapor occurs, and the pH of condensed water is in the 2.5 5.5 range. The study shows that CASA water heater has good corrosion resistance and a high heat efficiency of 88%. Compared with the heat exchangers produced by Honeywell and Beka, there is still much work to do in optimizing and improving the water heater.

  15. Heat recovery system employing a temperature controlled variable speed fan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jones, W.T.

    1986-05-20

    A heat recovery system is described for use in recovering heat from an industrial process producing a heated fluid comprising: a source of inlet air; a housing coupled to the source and including a heat exchanger; means for passing the heated fluid through the heat exchanger; the housing including means for moving a variable volume of air adjustable over a continuous range from the source through the heat exchanger; air discharge means communicating with the housing for discharging air which has passed through the heat exchanger; a control system including first temperature sensing means for sensing the discharge temperature ofmore » the discharge air moving through the discharge means and a control circuit coupled to the first temperature sensing means and to the moving means for varying the volume of air moved in response to the sensed discharge temperature to control the temperature of discharge air passing through the discharge means at a first predetermined value; and the control system including second temperature sensing means for sensing the temperature of the source of inlet air and valve means coupled to and controlled by the control circuit to cause liquid to bypass the heat exchanger when the inlet air temperature rises above a second predetermined value.« less

  16. Numerical study of heat transfer characteristics in BOG heat exchanger

    NASA Astrophysics Data System (ADS)

    Yan, Yan; Pfotenhauer, John M.; Miller, Franklin; Ni, Zhonghua; Zhi, Xiaoqin

    2016-12-01

    In this study, a numerical study of turbulent flow and the heat transfer process in a boil-off liquefied natural gas (BOG) heat exchanger was performed. Finite volume computational fluid dynamics and the k - ω based shear stress transport model were applied to simulate thermal flow of BOG and ethylene glycol in a full-sized 3D tubular heat exchanger. The simulation model has been validated and compared with the engineering specification data from its supplier. In order to investigate thermal characteristics of the heat exchanger, velocity, temperature, heat flux and thermal response were studied under different mass flowrates in the shell-side. The shell-side flow pattern is mostly determined by viscous forces, which lead to a small velocity and low temperature buffer area in the bottom-right corner of the heat exchanger. Changing the shell-side mass flowrate could result in different distributions of the shell-side flow. However, the distribution in the BOG will remain in a relatively stable pattern. Heat flux increases along with the shell-side mass flowrate, but the increase is not linear. The ratio of increased heat flux to the mass flow interval is superior at lower mass flow conditions, and the threshold mass flow for stable working conditions is defined as greater than 0.41 kg/s.

  17. Passive thermosyphon solar heating and cooling module with supplementary heating

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A collection of three quarterly reports from Sigma Research, Inc., covering progress and status from January through September 1977 are presented. Three heat exchangers are developed for use in a solar heating and cooling system for installation into single-family dwellings. Each exchanger consists of one heating and cooling module and one submerged electric water heating element.

  18. Geothermal Energy Retrofit

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bachman, Gary

    The Cleary University Geothermal Energy Retrofit project involved: 1. A thermal conductivity test; 2. Assessment of alternative horizontal and vertical ground heat exchanger options; 3. System design; 4. Asphalt was stripped from adjacent parking areas and a vertical geothermal ground heat exchanger system installed; 5. the ground heat exchanger was connected to building; 6. a system including 18 heat pumps, control systems, a manifold and pumps, piping for fluid transfer and ductwork for conditioned air were installed throughout the building.

  19. Microbial Fouling and its Effect on Power Generation.

    DTIC Science & Technology

    1981-09-01

    The tubular fouling reactor system (TFR) consists of a test block heat exchanger and a support system which includes water supply treatment facilities...and measurement instrumentation. Figure 8 is a schematic diagram of the system. Test block heat exchanger : The test block heat exchanger consists of...two adjacent aluminum cylindrical blocks (12.5 cm dia.) clamped to the section of tubing being tested (Fig. 9). The block is heated by electrical re

  20. Microtube strip heat exchanger

    NASA Astrophysics Data System (ADS)

    Doty, F. D.

    1992-07-01

    The purpose of this contract has been to explore the limits of miniaturization of heat exchangers with the goals of (1) improving the theoretical understanding of laminar heat exchangers, (2) evaluating various manufacturing difficulties, and (3) identifying major applications for the technology. A low-cost, ultra-compact heat exchanger could have an enormous impact on industry in the areas of cryocoolers and energy conversion. Compact cryocoolers based on the reverse Brayton cycle (RBC) would become practical with the availability of compact heat exchangers. Many experts believe that hardware advances in personal computer technology will rapidly slow down in four to six years unless lowcost, portable cryocoolers suitable for the desktop supercomputer can be developed. Compact refrigeration systems would permit dramatic advances in high-performance computer work stations with 'conventional' microprocessors operating at 150 K, and especially with low-cost cryocoolers below 77 K. NASA has also expressed strong interest in our MTS exchanger for space-based RBC cryocoolers for sensor cooling. We have demonstrated feasibility of higher specific conductance by a factor of five than any other work in high-temperature gas-to-gas exchangers. These laminar-flow, microtube exchangers exhibit extremely low pressure drop compared to alternative compact designs under similar conditions because of their much shorter flow length and larger total flow area for lower flow velocities. The design appears to be amenable to mass production techniques, but considerable process development remains. The reduction in materials usage and the improved heat exchanger performance promise to be of enormous significance in advanced engine designs and in cryogenics.

  1. A comprehensive review of milk fouling on heated surfaces.

    PubMed

    Sadeghinezhad, E; Kazi, S N; Dahari, M; Safaei, Mohammad Reza; Sadri, Rad; Badarudin, A

    2015-01-01

    Heat exchanger performance degrades rapidly during operation due to formation of deposits on heat transfer surfaces which ultimately reduces service life of the equipment. Due to scaling, product deteriorates which causes lack of proper heating. Chemistry of milk scaling is qualitatively understood and the mathematical models for fouling at low temperatures have been produced but the behavior of systems at ultra high temperature processing has to be studied further to understand in depth. In diversified field, the effect of whey protein fouling along with pressure drop in heat exchangers were conducted by many researchers. Adding additives, treatment of heat exchanger surfaces and changing of heat exchanger configurations are notable areas of investigation in milk fouling. The present review highlighted information about previous work on fouling, influencing parameters of fouling and its mitigation approach and ends up with recommendations for retardation of milk fouling and necessary measures to perform the task.

  2. Influence of collector heat capacity and internal conditions of heat exchanger on cool-down process of small gas liquefier

    NASA Astrophysics Data System (ADS)

    Saberimoghaddam, Ali; Bahri Rasht Abadi, Mohammad Mahdi

    2018-01-01

    Joule-Thomson cooling systems are commonly used in gas liquefaction. In small gas liquefiers, transient cool-down time is high. Selecting suitable conditions for cooling down process leads to decrease in time and cost. In the present work, transient thermal behavior of Joule-Thomson cooling system including counter current helically coiled tube in tube heat exchanger, expansion valve, and collector was studied using experimental tests and simulations. The experiments were performed using small gas liquefier and nitrogen gas as working fluid. The heat exchanger was thermally studied by experimental data obtained from a small gas liquefier. In addition, the simulations were performed using experimental data as variable boundary conditions. A comparison was done between presented and conventional methods. The effect of collector heat capacity and convection heat transfer coefficient inside the tubes on system performance was studied using temperature profiles along the heat exchanger.

  3. Self-defrosting recuperative air-to-air heat exchanger

    DOEpatents

    Drake, Richard L.

    1993-01-01

    A heat exchanger includes a stationary spirally or concentrically wound heat exchanger core with rotating baffles on upper and lower ends thereof. The rotating baffles include rotating inlets and outlets which are in communication with respective fixed inlets and outlets via annuli. The rotation of the baffles causes a concurrent rotation of the temperature distribution within the stationary exchanger core, thereby preventing frost build-up in some applications and preventing the formation of hot spots in other applications.

  4. Repairing Hard-to-Reach Cracks in Heat-Exchanger Tubes

    NASA Technical Reports Server (NTRS)

    Mills, R. C., Sr.; Duesberg, J.

    1986-01-01

    Inaccessible leaks repaired from accessible side of tube. Fish-Mouth insert placed in cut in leaky heat-exchanger tube. Insert welded or brazed to tube, and remaining open area of cut patched. Method developed for repairing leaks in nozzle coolant tubes of Space Shuttle main engine. Method also used on other types of tubular heat exchangers.

  5. 40 CFR Table 8 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Requirements for Heat Exchange Systems 8 Table 8 to Subpart VVVVVV of Part 63 Protection of Environment... Pollutants for Chemical Manufacturing Area Sources Pt. 63, Subpt. VVVVVV, Table 8 Table 8 to Subpart VVVVVV....11499, you must comply with the requirements for heat exchange systems as shown in the following table...

  6. 40 CFR Table 8 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Requirements for Heat Exchange Systems 8 Table 8 to Subpart VVVVVV of Part 63 Protection of Environment... Pollutants for Chemical Manufacturing Area Sources Pt. 63, Subpt. VVVVVV, Table 8 Table 8 to Subpart VVVVVV....11499, you must comply with the requirements for heat exchange systems as shown in the following table...

  7. 40 CFR Table 8 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Requirements for Heat Exchange Systems 8 Table 8 to Subpart VVVVVV of Part 63 Protection of Environment... Pollutants for Chemical Manufacturing Area Sources Pt. 63, Subpt. VVVVVV, Table 8 Table 8 to Subpart VVVVVV....11499, you must comply with the requirements for heat exchange systems as shown in the following table...

  8. 40 CFR Table 8 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Requirements for Heat Exchange Systems 8 Table 8 to Subpart VVVVVV of Part 63 Protection of Environment... Pollutants for Chemical Manufacturing Area Sources Pt. 63, Subpt. VVVVVV, Table 8 Table 8 to Subpart VVVVVV....11499, you must comply with the requirements for heat exchange systems as shown in the following table...

  9. 40 CFR Table 8 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Heat Exchange Systems

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Requirements for Heat Exchange Systems 8 Table 8 to Subpart VVVVVV of Part 63 Protection of Environment... Pollutants for Chemical Manufacturing Area Sources Pt. 63, Subpt. VVVVVV, Table 8 Table 8 to Subpart VVVVVV....11499, you must comply with the requirements for heat exchange systems as shown in the following table...

  10. 40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...

  11. 40 CFR 63.1422 - Compliance dates and relationship of this rule to existing applicable rules.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to... constitute compliance with the applicable provisions of this subpart with respect to that heat exchange...

  12. 40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...

  13. 40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...

  14. 21 CFR 500.45 - Use of polychlorinated biphenyls (PCB's) in the production, handling, and storage of animal feed.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Food and Drug Administration have revealed that heat exchange fluids for certain pasteurization equipment used in processing animal feed contain PCB's. Although heat exchange fluids in such equipment are... animal feed shall: (i) Have the heat exchange fluid used in existing equipment or machinery for handling...

  15. 40 CFR 63.11501 - What are the notification, recordkeeping, and reporting requirements?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... complies with the requirements in § 63.11499 for heat exchange systems.” (2) If you comply with the... provisions in an overlapping rule in accordance with § 63.11500, identify the affected CMPU, heat exchange... of repair, as specified in § 63.11495(a)(5). (ii) Records of small heat exchange system inspections...

  16. 40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...

  17. 40 CFR 63.1422 - Compliance dates and relationship of this rule to existing applicable rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to... constitute compliance with the applicable provisions of this subpart with respect to that heat exchange...

  18. 40 CFR 63.1422 - Compliance dates and relationship of this rule to existing applicable rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to... constitute compliance with the applicable provisions of this subpart with respect to that heat exchange...

  19. 40 CFR 63.11501 - What are the notification, recordkeeping, and reporting requirements?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... complies with the requirements in § 63.11499 for heat exchange systems.” (2) If you comply with the... provisions in an overlapping rule in accordance with § 63.11500, identify the affected CMPU, heat exchange... of repair, as specified in § 63.11495(a)(5). (ii) Records of small heat exchange system inspections...

  20. 40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of other requirements for heat exchange systems or waste management units. Paragraphs (n)(1) and (n... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to...

  1. 40 CFR 63.1422 - Compliance dates and relationship of this rule to existing applicable rules.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for the same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After the applicable compliance date specified in this subpart, if a heat exchange system subject to... constitute compliance with the applicable provisions of this subpart with respect to that heat exchange...

  2. 40 CFR 63.11985 - What notifications and reports must I submit and when?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) for equipment leaks. (3) You must include an identification of the heat exchange systems that are... requirements in this subpart for heat exchange systems.” (iv) “This facility complies with the requirements in... information specified in paragraphs (b)(3)(i) through (vi) of this section for heat exchange systems. (i) The...

  3. 40 CFR 63.11985 - What notifications and reports must I submit and when?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) for equipment leaks. (3) You must include an identification of the heat exchange systems that are... requirements in this subpart for heat exchange systems.” (iv) “This facility complies with the requirements in... information specified in paragraphs (b)(3)(i) through (vi) of this section for heat exchange systems. (i) The...

  4. 21 CFR 500.45 - Use of polychlorinated biphenyls (PCB's) in the production, handling, and storage of animal feed.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Food and Drug Administration have revealed that heat exchange fluids for certain pasteurization equipment used in processing animal feed contain PCB's. Although heat exchange fluids in such equipment are... animal feed shall: (i) Have the heat exchange fluid used in existing equipment or machinery for handling...

  5. Optimization of the Heat Exchangers of a Thermoelectric Generation System

    NASA Astrophysics Data System (ADS)

    Martínez, A.; Vián, J. G.; Astrain, D.; Rodríguez, A.; Berrio, I.

    2010-09-01

    The thermal resistances of the heat exchangers have a strong influence on the electric power produced by a thermoelectric generator. In this work, the heat exchangers of a thermoelectric generator have been optimized in order to maximize the electric power generated. This thermoelectric generator harnesses heat from the exhaust gas of a domestic gas boiler. Statistical design of experiments was used to assess the influence of five factors on both the electric power generated and the pressure drop in the chimney: height of the generator, number of modules per meter of generator height, length of the fins of the hot-side heat exchanger (HSHE), length of the gap between fins of the HSHE, and base thickness of the HSHE. The electric power has been calculated using a computational model, whereas Fluent computational fluid dynamics (CFD) has been used to obtain the thermal resistances of the heat exchangers and the pressure drop. Finally, the thermoelectric generator has been optimized, taking into account the restrictions on the pressure drop.

  6. Contributions Regarding the Aircraft Nuclear Propulsion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mitrica, Bogdan; Petre, Marian; Dima, Mihai Octavian

    2010-01-21

    The possibility to use a nuclear reactor for airplanes propulsion was investigated taking in to account 2 possible solutions: the direct cycle (where the fluid pass through the reactor's core) and the indirect cycle (where the fluid is passing through a heat exchanger). Taking in to account the radioprotection problems, the only realistic solution seems to be the indirect cycle, where the energy transfer should be performed by a heat exchanger that must work at very high speed of the fluid. The heat exchanger will replace the classical burning room. We had performed a more precise theoretical study for themore » nuclear jet engine regarding the performances of the nuclear reactor, of the heat exchanger and of the jet engine. It was taken in to account that in the moment when the burning room is replaced by a heat exchanger, a new model for gasodynamic process from the engine must be performed. Studies regarding the high flow speed heat transfer were performed.« less

  7. Sensor fault detection and isolation via high-gain observers: application to a double-pipe heat exchanger.

    PubMed

    Escobar, R F; Astorga-Zaragoza, C M; Téllez-Anguiano, A C; Juárez-Romero, D; Hernández, J A; Guerrero-Ramírez, G V

    2011-07-01

    This paper deals with fault detection and isolation (FDI) in sensors applied to a concentric-pipe counter-flow heat exchanger. The proposed FDI is based on the analytical redundancy implementing nonlinear high-gain observers which are used to generate residuals when a sensor fault is presented (as software sensors). By evaluating the generated residual, it is possible to switch between the sensor and the observer when a failure is detected. Experiments in a heat exchanger pilot validate the effectiveness of the approach. The FDI technique is easy to implement allowing the industries to have an excellent alternative tool to keep their heat transfer process under supervision. The main contribution of this work is based on a dynamic model with heat transfer coefficients which depend on temperature and flow used to estimate the output temperatures of a heat exchanger. This model provides a satisfactory approximation of the states of the heat exchanger in order to allow its implementation in a FDI system used to perform supervision tasks. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ranjan, Devesh

    Diffusion bonded heat exchangers are the leading candidates for the sCO 2 Brayton cycles in next generation nuclear power plants. Commercially available diffusion bonded heat exchangers utilize set of continuous semi-circular zigzag micro channels to increase the heat transfer area and enhance heat transfer through increased turbulence production. Such heat exchangers can lead to excessive pressure drop as well as flow maldistribution in the case of poorly designed flow distribution headers. The goal of the current project is to fabricate and test potential discontinuous fin patterns for diffusion bonded heat exchangers; which can achieve desired thermal performance at lower pressuremore » drops. Prototypic discontinuous offset rectangular and Airfoil fin surface geometries were chemically etched on to 316 stainless steel plate and sealed against an un-etched flat pate using O-ring seal emulating diffusion bonded heat exchangers. Thermal-hydraulic performance of these prototypic discontinuous fin geometries was experimentally evaluated and compared to the existing data for the continuous zigzag channels. The data generated from this project will serve as the database for future testing and validation of numerical models.« less

  9. Effectiveness of Humidification with Heat and Moisture Exchanger-booster in Tracheostomized Patients.

    PubMed

    Gonzalez, Isabel; Jimenez, Pilar; Valdivia, Jorge; Esquinas, Antonio

    2017-08-01

    The two most commonly used types of humidifiers are heated humidifiers and heat and moisture exchange humidifiers. Heated humidifiers provide adequate temperature and humidity without affecting the respiratory pattern, but overdose can cause high temperatures and humidity resulting in condensation, which increases the risk of bacteria in the circuit. These devices are expensive. Heat and moisture exchanger filter is a new concept of humidification, increasing the moisture content in inspired gases. This study aims to determine the effectiveness of the heat and moisture exchanger (HME)-Booster system to humidify inspired air in patients under mechanical ventilation. We evaluated the humidification provided by 10 HME-Booster for tracheostomized patients under mechanical ventilation using Servo I respirators, belonging to the Maquet company and Evita 4. There was an increase in the inspired air humidity after 1 h with the humidifier. The HME-Booster combines the advantages of heat and moisture exchange minimizing the negatives. It increases the amount of moisture in inspired gas in mechanically ventilated tracheostomized patients. It is easy and safe to use. The type of ventilator used has no influence on the result.

  10. Cost Scaling of a Real-World Exhaust Waste Heat Recovery Thermoelectric Generator: A Deeper Dive

    NASA Astrophysics Data System (ADS)

    Hendricks, Terry J.; Yee, Shannon; LeBlanc, Saniya

    2016-03-01

    Cost is equally important to power density or efficiency for the adoption of waste heat recovery thermoelectric generators (TEG) in many transportation and industrial energy recovery applications. In many cases, the system design that minimizes cost (e.g., the /W value) can be very different than the design that maximizes the system's efficiency or power density, and it is important to understand the relationship between those designs to optimize TEG performance-cost compromises. Expanding on recent cost analysis work and using more detailed system modeling, an enhanced cost scaling analysis of a waste heat recovery TEG with more detailed, coupled treatment of the heat exchangers has been performed. In this analysis, the effect of the heat lost to the environment and updated relationships between the hot-side and cold-side conductances that maximize power output are considered. This coupled thermal and thermoelectric (TE) treatment of the exhaust waste heat recovery TEG yields modified cost scaling and design optimization equations, which are now strongly dependent on the heat leakage fraction, exhaust mass flow rate, and heat exchanger effectiveness. This work shows that heat exchanger costs most often dominate the overall TE system costs, that it is extremely difficult to escape this regime, and in order to achieve TE system costs of 1/W it is necessary to achieve heat exchanger costs of 1/(W/K). Minimum TE system costs per watt generally coincide with maximum power points, but preferred TE design regimes are identified where there is little cost penalty for moving into regions of higher efficiency and slightly lower power outputs. These regimes are closely tied to previously identified low cost design regimes. This work shows that the optimum fill factor F opt minimizing system costs decreases as heat losses increase, and increases as exhaust mass flow rate and heat exchanger effectiveness increase. These findings have profound implications on the design and operation of various TE waste heat recovery systems. This work highlights the importance of heat exchanger costs on the overall TEG system costs, quantifies the possible TEG performance-cost domain space based on heat exchanger effects, and provides a focus for future system research and development efforts.

  11. Energy absorber for sodium-heated heat exchanger

    DOEpatents

    Essebaggers, J.

    1975-12-01

    A heat exchanger is described in which water-carrying tubes are heated by liquid sodium and in which the results of accidental contact between the water and the sodium caused by failure of one or more of the water tubes is minimized. An energy absorbing chamber contains a compressible gas and is connected to the body of flowing sodium by a channel so that, in the event of a sodium-water reaction, products of the reaction will partially fill the energy absorbing chamber to attenuate the rise in pressure within the heat exchanger.

  12. Heat rejection system

    DOEpatents

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

    1980-01-01

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

  13. RELAP5-3D Modeling of Heat Transfer Components (Intermediate Heat Exchanger and Helical-Coil Steam Generator) for NGNP Application

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    N. A. Anderson; P. Sabharwall

    2014-01-01

    The Next Generation Nuclear Plant project is aimed at the research and development of a helium-cooled high-temperature gas reactor that could generate both electricity and process heat for the production of hydrogen. The heat from the high-temperature primary loop must be transferred via an intermediate heat exchanger to a secondary loop. Using RELAP5-3D, a model was developed for two of the heat exchanger options a printed-circuit heat exchanger and a helical-coil steam generator. The RELAP5-3D models were used to simulate an exponential decrease in pressure over a 20 second period. The results of this loss of coolant analysis indicate thatmore » heat is initially transferred from the primary loop to the secondary loop, but after the decrease in pressure in the primary loop the heat is transferred from the secondary loop to the primary loop. A high-temperature gas reactor model should be developed and connected to the heat transfer component to simulate other transients.« less

  14. Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Anderson, Mark; Nellis, Greg; Corradini, Michael

    2012-10-19

    The objective of this project is to produce the necessary data to evaluate the performance of the supercritical carbon dioxide cycle. The activities include a study of materials compatibility of various alloys at high temperatures, the heat transfer and pressure drop in compact heat exchanger units, and turbomachinery issues, primarily leakage rates through dynamic seals. This experimental work will serve as a test bed for model development and design calculations, and will help define further tests necessary to develop high-efficiency power conversion cycles for use on a variety of reactor designs, including the sodium fast reactor (SFR) and very high-temperaturemore » gas reactor (VHTR). The research will be broken into three separate tasks. The first task deals with the analysis of materials related to the high-temperature S-CO{sub 2} Brayton cycle. The most taxing materials issues with regard to the cycle are associated with the high temperatures in the reactor side heat exchanger and in the high-temperature turbine. The system could experience pressures as high as 20MPa and temperatures as high as 650°C. The second task deals with optimization of the heat exchangers required by the S-CO{sub 2} cycle; the S-CO{sub 2} flow passages in these heat exchangers are required whether the cycle is coupled with a VHTR or an SFR. At least three heat exchangers will be required: the pre-cooler before compression, the recuperator, and the heat exchanger that interfaces with the reactor coolant. Each of these heat exchangers is unique and must be optimized separately. The most challenging heat exchanger is likely the pre-cooler, as there is only about a 40°C temperature change but it operates close to the CO{sub 2} critical point, therefore inducing substantial changes in properties. The proposed research will focus on this most challenging component. The third task examines seal leakage through various dynamic seal designs under the conditions expected in the S-CO{sub 2} cycle, including supercritical, choked, and two-phase flow conditions.« less

  15. Oscillating side-branch enhancements of thermoacoustic heat exchangers

    DOEpatents

    Swift, Gregory W.

    2003-05-13

    A regenerator-based engine or refrigerator has a regenerator with two ends at two different temperatures, through which a gas oscillates at a first oscillating volumetric flow rate in the direction between the two ends and in which the pressure of the gas oscillates, and first and second heat exchangers, each of which is at one of the two different temperatures. A dead-end side branch into which the gas oscillates has compliance and is connected adjacent to one of the ends of the regenerator to form a second oscillating gas flow rate additive with the first oscillating volumetric flow rate, the compliance having a volume effective to provide a selected total oscillating gas volumetric flow rate through the first heat exchanger. This configuration enables the first heat exchanger to be configured and located to better enhance the performance of the heat exchanger rather than being confined to the location and configuration of the regenerator.

  16. Application of horizontal spiral coil heat exchanger for volatile organic compounds (VOC) emission control.

    PubMed

    Deshpande, P M; Dawande, S D

    2013-04-01

    The petroleum products have wide range of volatility and are required to be stored in bulk. The evaporation losses are significant and it is a economic as well as environmental concern, since evaporative losses of petroleum products cause increased VOC in ambient air. Control of these losses poses a major problem for the storage tank designers. Ever rising cost of petroleum products further adds to the gravity of the problem. Condensation is one of the technologies for reducing volatile organic compounds emissions. Condensation is effected by condenser, which is basically a heat exchanger and the heat exchanger configuration plays an important role. The horizontal spiral coil heat exchanger is a promising configuration that finds an application in VOC control. This paper attempts to understand underlying causes of emissions and analyse the option of horizontal spiral coil heat exchanger as vent condenser.

  17. Pulse Detonation Engine Thrust Tube Heat Exchanger for Flash Vaporization and Supercritical Heating of JP-8

    DTIC Science & Technology

    2005-03-01

    47 Figure 21. Construction of the long heat exchanger with helical rod welded in place.... 48 Figure 22. Heat exchanger...not at a temperature at or above the dew point temperature of the mixture, some of the fuel in the mixture will re- condense . The concept of...diao (25) Where kamb = Thermal conductivity of the air [W/(m-K)] Nufc = Nusselt number for free convection The Nussult number

  18. Heat exchanger and method of making. [rocket lining

    NASA Technical Reports Server (NTRS)

    Fortini, A.; Kazaroff, J. M. (Inventor)

    1980-01-01

    A heat exchange of increased effectiveness is disclosed. A porous metal matrix is disposed in a metal chamber or between walls through which a heat-transfer fluid is directed. The porous metal matrix has internal bonds and is bonded to the chamber in order to remove all thermal contact resistance within the composite structure. Utilization of the invention in a rocket chamber is disclosed as a specific use. Also disclosed is a method of constructing the heat exchanger.

  19. Proceedings of the NITINOL Heat Engine Conference, 26-27 September 1978, Silver Spring, Maryland

    DTIC Science & Technology

    1978-09-27

    allowed us to design, build, and test various engine designs, while exploring advanced concepts with computer modeling of motor dynamics and heat exchange ...exclude the effects of element geometi y and other material parameters which affect the heat exchange rate and kinetics of the SRP. 5-3...is in Rference 8. 13. In the present work we exclude the effects of element geometry and other material parameters which affect the heat exchange

  20. Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Baharin, Nuraida'Aadilia; Arzami, Amir Afiq; Singh, Baljit; Remeli, Muhammad Fairuz; Tan, Lippong; Oberoi, Amandeep

    2017-04-01

    In this study, a thermoelectric generator heat exchanger system was designed and simulated for electricity generation from solar pond. A thermoelectric generator heat exchanger was studied by using Computational Fluid Dynamics to simulate flow and heat transfer. A thermoelectric generator heat exchanger designed for passive in-pond flow used in solar pond for electrical power generation. A simple analysis simulation was developed to obtain the amount of electricity generated at different conditions for hot temperatures of a solar pond at different flow rates. Results indicated that the system is capable of producing electricity. This study and design provides an alternative way to generate electricity from solar pond in tropical countries like Malaysia for possible renewable energy applications.

  1. Nanomodified polymer materials for regenerative heat exchangers

    NASA Astrophysics Data System (ADS)

    Shchegolkov, Alexander; Shchegolkov, Alexey; Dyachkova, Tatyana

    2017-11-01

    The paper presents thermophysical properties of nanomodified paraffin mixed with polymers as polyethylene or fluoroplastic, which may be effectively used for the development of heat exchange elements of personal protective equipment. It has been experimentally shown that the heat exchangers based on the nanomodified polymer composites have twofold mass compared to the standard regenerative heat exchanger with comparable dimensions. The best result has been obtained on the basis of composite containing polyethylene and paraffin modified with CNTs, which thermal conductivity is 1.6 times higher than forconventional paraffin. The application of carbon nanostructures as the modifiers of heat storage materials improves cooling efficiency by 14.9-17.9 °C by creating more comfortable conditions for breathing via personal protective equipment.

  2. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, B.A.; Zawacki, T.S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

  3. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

  4. Exergy analysis of large-scale helium liquefiers: Evaluating design trade-offs

    NASA Astrophysics Data System (ADS)

    Thomas, Rijo Jacob; Ghosh, Parthasarathi; Chowdhury, Kanchan

    2014-01-01

    It is known that higher heat exchanger area, more number of expanders with higher efficiency and more involved configuration with multi-pressure compression system increase the plant efficiency of a helium liquefier. However, they involve higher capital investment and larger size. Using simulation software Aspen Hysys v 7.0 and exergy analysis as the tool of analysis, authors have attempted to identify various trade-offs while selecting the number of stages, the pressure levels in compressor, the cold-end configuration, the heat exchanger surface area, the maximum allowable pressure drop in heat exchangers, the efficiency of expanders, the parallel/series connection of expanders etc. Use of more efficient cold ends reduces the number of refrigeration stages and the size of the plant. For achieving reliability along with performance, a configuration with a combination of expander and Joule-Thomson valve is found to be a better choice for cold end. Use of multi-pressure system is relevant only when the number of refrigeration stages is more than 5. Arrangement of expanders in series reduces the number of expanders as well as the heat exchanger size with slight expense of plant efficiency. Superior heat exchanger (having less pressure drop per unit heat transfer area) results in only 5% increase of plant performance even when it has 100% higher heat exchanger surface area.

  5. Heat Recovery System

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Ball Metal's design of ducting and controls for series of roof top heat exchangers was inspired by Tech Briefs. Heat exchangers are installed on eight press and coating lines used to decorate sheet metal. The heat recovery system provides an estimated energy savings of more than $250,000 per year.

  6. In-Space technology experiments program. A high efficiency thermal interface (using condensation heat transfer) between a 2-phase fluid loop and heatpipe radiator: Experiment definition phase

    NASA Technical Reports Server (NTRS)

    Pohner, John A.; Dempsey, Brian P.; Herold, Leroy M.

    1990-01-01

    Space Station elements and advanced military spacecraft will require rejection of tens of kilowatts of waste heat. Large space radiators and two-phase heat transport loops will be required. To minimize radiator size and weight, it is critical to minimize the temperature drop between the heat source and sink. Under an Air Force contract, a unique, high-performance heat exchanger is developed for coupling the radiator to the transport loop. Since fluid flow through the heat exchanger is driven by capillary forces which are easily dominated by gravity forces in ground testing, it is necessary to perform microgravity thermal testing to verify the design. This contract consists of an experiment definition phase leading to a preliminary design and cost estimate for a shuttle-based flight experiment of this heat exchanger design. This program will utilize modified hardware from a ground test program for the heat exchanger.

  7. Numerical investigation of transient behaviour of the recuperative heat exchanger in a MR J-T cryocooler using different heat transfer correlations

    NASA Astrophysics Data System (ADS)

    Damle, R. M.; Ardhapurkar, P. M.; Atrey, M. D.

    2016-12-01

    In J-T cryocoolers operating with mixed refrigerants (nitrogen-hydrocarbons), the recuperative heat exchange takes place under two-phase conditions. Simultaneous boiling of the low pressure stream and condensation of the high pressure stream results in higher heat transfer coefficients. The mixture composition, operating conditions and the heat exchanger design are crucial for obtaining the required cryogenic temperature. In this work, a one-dimensional transient algorithm is developed for the simulation of the two-phase heat transfer in the recuperative heat exchanger of a mixed refrigerant J-T cryocooler. Modified correlation is used for flow boiling of the high pressure fluid while different condensation correlations are employed with and without the correction for the low pressure fluid. Simulations are carried out for different mixture compositions and numerical predictions are compared with the experimental data. The overall heat transfer is predicted reasonably well and the qualitative trends of the temperature profiles are also captured by the developed numerical model.

  8. Fluidized-Bed Heat Transfer Modeling for the Development of Particle/Supercritical-CO2 Heat Exchanger

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ma, Zhiwen; Martinek, Janna G

    Concentrating solar power (CSP) technology is moving toward high-temperature and high-performance design. One technology approach is to explore high-temperature heat-transfer fluids and storage, integrated with a high-efficiency power cycle such as the supercritical carbon dioxide (s-CO2) Brayton power cycle. The s-CO2 Brayton power system has great potential to enable the future CSP system to achieve high solar-to-electricity conversion efficiency and to reduce the cost of power generation. Solid particles have been proposed as a possible high-temperature heat-transfer medium that is inexpensive and stable at high temperatures above 1,000 degrees C. The particle/heat exchanger provides a connection between the particles andmore » s-CO2 fluid in the emerging s-CO2 power cycles in order to meet CSP power-cycle performance targets of 50% thermal-to-electric efficiency, and dry cooling at an ambient temperature of 40 degrees C. The development goals for a particle/s-CO2 heat exchanger are to heat s-CO2 to =720 degrees C and to use direct thermal storage with low-cost, stable solid particles. This paper presents heat-transfer modeling to inform the particle/s-CO2 heat-exchanger design and assess design tradeoffs. The heat-transfer process was modeled based on a particle/s-CO2 counterflow configuration. Empirical heat-transfer correlations for the fluidized bed and s-CO2 were used in calculating the heat-transfer area and optimizing the tube layout. A 2-D computational fluid-dynamics simulation was applied for particle distribution and fluidization characterization. The operating conditions were studied from the heat-transfer analysis, and cost was estimated from the sizing of the heat exchanger. The paper shows the path in achieving the cost and performance objectives for a heat-exchanger design.« less

  9. Experimental study of heat transfer enhancement due to the surface vibrations in a flexible double pipe heat exchanger

    NASA Astrophysics Data System (ADS)

    Hosseinian, A.; Meghdadi Isfahani, A. H.

    2018-04-01

    In this study, the heat transfer enhancement due to the surface vibration for a double pipe heat exchanger, made of PVDF, is investigated. In order to create forced vibrations (3-9 m/s2, 100 Hz) on the outer surface of the heat exchanger electro-dynamic vibrators are used. Experiments were performed at inner Reynolds numbers ranging from 2533 to 9960. The effects of volume flow rate and temperature on heat transfer performance are evaluated. Results demonstrated that heat transfer coefficient increases by increasing vibration level and mass flow rate. The most increase in heat transfer coefficient is 97% which is obtained for the highest vibration level (9 m/s2) in the experiment range.

  10. Self-defrosting recuperative air-to-air heat exchanger

    DOEpatents

    Drake, R.L.

    1993-12-28

    A heat exchanger is described which includes a stationary spirally or concentrically wound heat exchanger core with rotating baffles on upper and lower ends thereof. The rotating baffles include rotating inlets and outlets which are in communication with respective fixed inlets and outlets via annuli. The rotation of the baffles causes a concurrent rotation of the temperature distribution within the stationary exchanger core, thereby preventing frost build-up in some applications and preventing the formation of hot spots in other applications. 3 figures.

  11. ETR HEAT EXCHANGER BUILDING, TRA644. WORKERS CHECK INTERIOR OF ONE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ETR HEAT EXCHANGER BUILDING, TRA-644. WORKERS CHECK INTERIOR OF ONE OF THE TWELVE HEAT EXCHANGER UNITS. COOLANT FROM ETR WILL ENTER EXCHANGERS AT TEMPERATURE OF 137.5 DEGREES F. AND LEAVE THE SYSTEM AT 110 DEGREES F. SECONDARY WATER WILL ENTER AT 78 DEGREES F. AND LEAVE SYSTEM AT 110 DEGREES F. INL NEGATIVE NO. 56-3712. R.G. Larsen, Photographer, 11/13/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  12. Multi-stage flash degaser

    DOEpatents

    Rapier, Pascal M.

    1982-01-01

    A multi-stage flash degaser (18) is incorporated in an energy conversion system (10) having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger (22) in order that the heat exchanger (22) and a turbine (48) and condenser (32) of the system (10) can operate at optimal efficiency.

  13. Heat exchanger with a removable tube section

    DOEpatents

    Wolowodiuk, W.; Anelli, J.

    1975-07-29

    A heat exchanger is described in which the tube sheet is secured against primary liquid pressure, but which allows for easy removal of the tube section. The tube section is supported by a flange which is secured by a number of shear blocks, each of which extends into a slot which is immovable with respect to the outer shell of the heat exchanger. (auth)

  14. 40 CFR 89.419 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements are as follows: (1) This sampling system requires the use of a PDP-CVS and a heat exchanger or a CFV-CVS with either a heat exchanger or electronic flow compensation. Figure 2 in appendix A to this..., either a heat exchanger or electronic flow compensation is required (see Figure 3 in appendix A to this...

  15. 40 CFR 89.419 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements are as follows: (1) This sampling system requires the use of a PDP-CVS and a heat exchanger or a CFV-CVS with either a heat exchanger or electronic flow compensation. Figure 2 in appendix A to this..., either a heat exchanger or electronic flow compensation is required (see Figure 3 in appendix A to this...

  16. 40 CFR 1066.125 - Data updating, recording, and control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... minimum recording frequency, such as for sample flow rates from a CVS that does not have a heat exchanger... exhaust flow rate from a CVS with a heat exchanger upstream of the flow measurement 1 Hz. 40 CFR 1065.545§ 1066.425 Diluted exhaust flow rate from a CVS without a heat exchanger upstream of the flow measurement...

  17. 40 CFR 89.419 - Dilute gaseous exhaust sampling and analytical system description.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements are as follows: (1) This sampling system requires the use of a PDP-CVS and a heat exchanger or a CFV-CVS with either a heat exchanger or electronic flow compensation. Figure 2 in appendix A to this..., either a heat exchanger or electronic flow compensation is required (see Figure 3 in appendix A to this...

  18. 40 CFR 63.11501 - What are the notification, recordkeeping, and reporting requirements, and how may I assert an...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....11499 for heat exchange systems.” (2) If you comply with the alternative standard as specified in Table... accordance with § 63.11500, identify the affected CMPU, heat exchange system, and/or wastewater system... delay of repair, as specified in § 63.11495(a)(5). (ii) Records of small heat exchange system...

  19. 40 CFR 63.481 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... provisions of § 63.170 shall occur no later than June 19, 2001. (6) Compliance with the heat exchange system... requirements for heat exchange systems or waste management units. Paragraphs (l)(1) and (l)(2) of this section... compliance date specified in this subpart, if a heat exchange system subject to this subpart is also subject...

  20. 40 CFR 63.481 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Compliance with the heat exchange system provisions of § 63.104 shall occur no later than June 19, 2001. (e... other requirements for heat exchange systems or waste management units. Paragraphs (l)(1) and (l)(2) of... same heat exchange system(s) or waste management unit(s) that are subject to this subpart. (1) After...

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