Showing papers on "Heat exchanger published in 1988"

Humidifier module for use in a gas humidification assembly

Abstract: The humidifier module for use in a gas humidification unit has a humidification chamber and a water heating chamber separated by a water vapor permeable, liquid water impermeable membrane. Gas inlet and outlet ports are provided in the humidification chamber, a water inlet port is provided for the water heating chamber, a water inlet port is provided for the water heating chamber, and a heat exchange wall is provided on one side of the water heating chamber to receive heat from a heat source in the humidification assembly. The gas humidification assembly has an enclosure adjacent the heat source, for receiving the humidifier module, a water supply source, and a controller of the heater and water supply to the humidifier module. A sensor is provided for monitoring the level of fluid within the humidification chamber, and another sensor is provided for monitoring the level of water within the water heating chamber.

Refrigerant recovery and purification system

Abstract: A refrigerant recovery system which includes a compressor having an input coupled through an evaporator and through a solenoid valve to the refrigeration system from which refrigerant is to be withdrawn, and an output coupled through a condenser to a refrigerant storage container. The evaporator and condenser are contained within a closed cylindrical canister for heat exchange and oil separation, the canister having an oil drain valve in the bottom. The refrigerant storage container is carried by a scale having a limit switch coupled to control electronics to prevent or terminate further refrigerant recovery when the container is full. The entire system, including the control electronics, is mounted on a two-wheel hand truck to facilitate transport to a job site such as a building air conditioning or heat pump system. Apparatus for purifying recovered refrigerant includes a replaceable core filter/dryer, and a liquid pump for circulating refrigerant from the liquid port of the storage container through the core and then to the container vapor port. A differential pressure gauge is connected across the filter/dryer to indicate need for core replacement. A moisture indicator displays water concentration in the refrigerant. The purification apparatus may be either separate from or combined with the recovery system.

Heat Transfer Equipment Design

Abstract: A comprehensive presentation is made of state-of-the-art configurations and design methodologies for heat transfer devices applicable to industrial processes, automotive systems, air conditioning/refrigeration, cryogenics, and petrochemicals refining. Attention is given to topics in heat exchanger mechanical design, single-phase convection processes, thermal design, two-phase exchanger thermal design, heat-transfer augmentation, and rheological effects. Computerized analysis and design methodologies are presented for the range of heat transfer systems, as well as advanced methods for optimization and performance projection.

Dri-Pc humidity and temperature controller

Abstract: A temperature and humidity control system for natatoriums. The system provides a constant volume of air circulation which is used to control temperature and humidity in the natatorium while inhibiting the accumulation of moisture on the surfaces defining the natatorium. Usually, ambient air is introduced into the system and moisture latent air discharged from the system under controlled conditions. When the humidity of the ambient air is too great the system operates in a self-contained cycle. Return air from the natatorium flowing through the system is treated to maximize its relative humidity. Subsequently, it flows across a cooling coil. This cooled air flows through a heat exchange module where it is placed in exchange relationship with the air being drawn from the natatorium. It cools the air drawn from the natatorium to maximize its relative humidity and this air in turn flows across the refrigeration coil removing substantial quantities of moisture. Combining the refrigeration coil with the heat transfer module and the other components in the system, the sensible/latent heat split is shifted towards higher latent output increasing the overall efficiency of the system as a dehumidification device.

Fouling Science and Technology

Abstract: 1. Fundamentals and Economics.- General Fouling Problems.- General Thermal Fouling Models.- The Economics of Fouling.- 2. Monitoring Equipment.- Liquid Fouling Monitoring Equipment.- Gas-Side Fouling Monitoring Equipment.- Monitoring Fouling using a Novel Technique.- 3. Adhesion.- Adhesion and Removal of Particles - I.- Adhesion and Removal of Particles - II.- Aspects of Cell Adhesion.- 4. Particulate Fouling.- Particulate Fouling of Heat Transfer Surfaces: Mechanisms and Models.- Stochastic Model for the Induction Step on Particulate Fouling.- Fouling by Aqueous Suspensions of Kaolin and Magnetite: Hydrodynamic and Surface Phenomena Effects.- Gas Side Fouling.- 5. Biological Fouling.- Biological Fouling: Basic Science and Models.- Effect of Design and Operating Variables on Biofouling.- Surface Bound Biocides - A Novel Possibility to Prevent Biofouling.- Experimental Investigation of Marine Biofouling and Corrosion for Tropical Seawater.- 6. Crystallisation Fouling.- Crystallisation Fouling - Basic Science and Models.- Deposition of Hardness Salts.- Crystallisation of Organic Materials.- Fouling of Cryogenic Liquids.- 7. Chemical Reaction Fouling.- Basic Science and Models of Reaction Fouling.- Chemical Reaction Fouling of Heat Exchangers.- Fouling from Light Hydrocarbons on Metal Surfaces.- Fouling of Catalysts: Industrial Examples.- The Fouling of Catalysts by Deposition of Filamentous Carbon.- Droplets and Filaments: on the Fouling of Metal Surfaces by Carbonaceous Material from Hydrocarbon Gases above 850K.- Carbon Limits in Steam Reforming.- Carbon Deposition in Steam-Cracking.- 8. Design and Operation of Heat Exchangers.- Basic Relationships for Heat Exchangers and Impact of Fouling on Design.- Selection of Heat Exchangers.- General Design of Heat Exchangers for Fouling Conditions.- Basic Concepts in Heat Exchanger Network Modelling.- The Fouling of Heat Exchanger Networks.- Compensating for Fouling in Heat Exchanger Networks.- 9. Food Processing Fouling.- Fouling by Milk and Dairy Product and Cleaning of Heat Exchange Surfaces.- On-Line Measurement of Fouling and Cleaning of Industrial UHT Exchangers.- 10. Fouling in Industrial Water Systems.- Effectiveness of Biocides.- Case Study-Clean-up of a Coke Oven Cooling System.- Corrision Fouling: Liquid Side.- Avoiding Fouling and Corrosion in Water Cooled Heat Exchangers: The Expert System Approach.- Fouling of Geothermal Energy Systems.- Geothermal Water Scaling in Heat Exchangers.- 11. Fouling in Furnaces.- High Temperature Fouling: The Nature of Deposits.- High Temperature Gas-Side Fouling Case Study.- 12. Discussions.- Cooling Water Fouling - Summary of Discussion.- Debate: Food Processing Fouling.- Cleaning of Fouled Surfaces: A Discussion.- Chemical Reaction Fouling Debate.- Debate on Gas-Side Fouling.

Liquid-cooled, flat plate heat exchanger

Abstract: A one-piece, substantially flat and very thin heat exchanger core in accordance with this invention has two flat and parallel surfaces, with each of said surfaces being suitable as a mounting surface for a number of heat producing electronic chips. These surfaces are closely spaced and separated by a single cavity for conveying a fluid coolant, and the cavity contains a plurality of closely spaced pins extending the full distance between the parallel surfaces. The pins are formed and permanently joined to both of the parallel surfaces, and quite significantly, this is accomplished with creation of a seam. Each pin is capable of having a hole installed through for its entire length, from one of the flat surfaces to the other, without breaching the fluid cavity and without creating a path for fluid to leak from the fluid cavity to the ambient. Also significant is the novel method by which this heat exchanger is constructed.

Particulate Fouling of Heat Transfer Surfaces: Mechanisms and Models

Abstract: In the present context particulate fouling is defined as the accumulation of solid particles suspended in a fluid onto a heat transfer surface. Some of the mechanisms which occur are similar to those which govern the fouling of membranes or filters. Unlike filtration surfaces, however, heat transfer surfaces are more often parallel than perpendicular to the flow. Furthermore, the presence of temperature gradients near a heat transfer surface can perturb the isothermal fouling mechanisms as well as introduce additional particle transport mechanisms, thereby drastically modifying the rate and extent of fouling.

Optimal control system for refrigeration-coupled thermal energy storage

Abstract: A refrigeration-coupled thermal energy storage control system includes apparatus and methodology for establishing target cooling and heating storage conditions, and selecting between cooling and heating modes, based upon outdoor temperature history, and for operating the system until the target storage conditions are achieved. In the cooling mode, cooling storage quantity increases with increases in outdoor temperature, and in the heating mode heating storage quantity increases with decreases in outdoor temperature. The system further includes apparatus and methodology for biasing operation of cooling, heating and domestic hot water production modes during off-peak periods, rather than during one-peak periods. The system incorporates logic for fan coil pump seasonal interlocking, outdoor heat exchanger fan operation, outdoor heat exchanger coil defrosting, and compressor crankcase heater operation.

Heat exchanger fabricated from polymer compositions

Abstract: A panel heat exchanger is disclosed. The heat exchanger comprises a generally planar panel having a pair of relatively thin unitary outer walls formed from a composition of a thermoplastic polymer, expecially a polyamide. The walls, which have a thickness of less than 0.7 mm, are bonded together to form a labryinth of fluid passages between the walls. The passages extend between inlet and outlet means and occupy a substantial proportion of the area of the panel. The heat exchangers are relatively economical to manufacture and may be used in a variety of end uses, depending on the properties of the polymer composition, including in some instances as heat exchangers in automobiles.

Air-conditioning apparatus

Abstract: A multiroom air conditioning apparatus includes an outdoor side unit having a compressor and an outdoor heat exchanger, and a plurality of room units having an indoor heat exchanger A high-pressure gas pipe and a low-pressure gas pipe, connected to the compressor, are branched so that a high-side branch pipe and a low-side branch pipe are connected to the outdoor heat exchanger via outside valves A liquid pipe through which a refrigerant passes from the high-pressure gas pipe is connected to the outdoor heat exchanger, and branched to provide liquid pipes The indoor heat exchanger is connected to the branched liquid pipes via expansion device and to the high-side branch pipe and the low-side branch pipe via inside valves By controlling the outside and inside valves, a selected room unit or units can be cooled or heated

Heat exchanger for fuel cell power plant reformer

Abstract: 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.

Cryogenic cooling system with precooling stage

Abstract: A cryogenic cooling system using hydrogen as a primary refrigerant fluid and oxygen as a secondary refrigerant fluid to precool the hydrogen gas below its inversion temperature In a first embodiment, the cryogenic cooling system (10) includes an electrochemical compressor (12) operative to compress hydrogen and oxygen gas without any moving parts Compressed oxygen from the electrochemical compressor passes through a regenerative heat exchanger (24) in heat transfer relationship with low pressure oxygen, and expands through a Joule-Thomson expansion valve (28) absorbing heat from a compressed hydrogen gas stream in a precooler heat exchange (30) The low pressure oxygen provides additional cooling in a parasitic heat exchangeer (36), returning to the electrochemical compressor through the regenerative heat exchanger (24) Compressed hydrogen flows through a regenerative heat exchange (44) in heat transfer relationship with low pressure hydrogen, and is precooled as it passes through the precooler heat exchanger A second regenerative heat exchaner (50) provides additional heat transfer with the low pressure hydrogen gas stream prior to expansion of the compressed hydrogen in a Joule-Thomson expansion valve (54) The expanding hydrogen cools a load in heat exchanger (58), returning to the electrochemical compressor through regenerative heat exchangers 44 to 50 In the second embodiment, a mechanical water pump is provided to compress water, which is used as an intermediate media between the low pressure and high pressure hydrogen and oxygen gas streams In both embodiments, the hydrogen and oxygen gas are electrochemically combined into water using a catalytic membrane (124) and then disassociated by electrolysis into their respective oxygen and hydrogen gas streams using another catalytic membrane (144)

Method of manufacturing heat exchangers

Abstract: This invention relates to an improved method of manufacturing a heat exchanger element. In a second aspect the invention concerns a heat exchanger element itself. In the third aspect the invention concerns a reservoir suitable for housing the heat exchanger element to form a heat exchanger. The element is manufactured by extruding polyethylene tubes and winding them into spiral coils. Each coil is located along the length of a rigid horizontal spacer bar in order to maintain even spacing of the coil. The element comprises a stack of coils which are not restrained against vertical movement. The element also comprises a cylindrical void through the centre.

Direct-Contact Heat Transfer

Abstract: Direct-Contact Heat Transfer Processes.- Industrial Practices and Needs.- Computational Techniques for Two-Phase Flow and Heat Transfer.- Industrial Practices and Two-Phase Transport.- Mass Transfer Effects in Heat Transfer Processes.- Liquid-Liquid Processes.- Discussion of Mass Transfer Effects and Liquid-Liquid Transport.- Solids Motion and Heat Transfer in Gas Fluidized Beds.- High-Temperature Solids-Gas Interactions.- Direct-Contact Heat Transfer in Solid-Gas Systems.- Direct-Contact Evaporation.- Direct-Contact Condensation.- Discussion of Direct Contact Condensation and Evaporation.- Research Needs in Direct-Contact Heat Exchange.

Engine cooling system for skid steer loaders

Abstract: A skid steer loader includes an engine compartment and a heat exchanger compartment located behind the operator's compartment. A fan shroud mounted between the heat exchanger compartment and the engine compartment has a first air intake aperture opening into the heat exchanger compartment, a second air intake aperture opening into the engine compartment, and an exhaust port. A double-bladed radial fan is mounted for rotation within the fan shroud between the first and second air intake apertures. A fan drive mechanism coupled to the engine rotates the fan. The fan simultaneously induces a heat exchanger airflow of ambient air through the heat exchanger compartment and into the fan shroud through the first air intake aperture, and an engine compartment evacuation airflow from within the engine compartment into the fan shroud through the second air intake aperture. The heat exchanger airflow and engine compartment evacuation airflows are mixed and jointly discharged from the loader through the exhaust port.

Filtered environmental control system

Abstract: An air conditioning system, being powered by a supply (52) of compressed air, has an air cycle machine (12) which incorporates a regenerable filter (18). The filter (18) receives pressurized air for filtration from the air cycle machine compressor (30), and receives purge air from the air cycle machine turbine (32) downstream of a load heat exchanger (16). The air cools the load before purging the filter (18) thereby minimizing system power requirements.

System and method for reducing gas compressor energy requirements

Abstract: An improved system for reducing the work required by a gas compressor in compressing a gas, comprising a gas compressor, a post-compression heat exchanger operably coupled to said gas compressor downstream therefrom to recover heat energy from a compressed amount of gas, and a means for reducing the work required by said gas compressor to compress a pre-compression amount of gas utilizing said recovered heat energy to provide cooling for the pre-compression amount of gas wherein such means includes an absorption chiller using the heat energy of compression to providing cooling for the gas to be compressed prior to compression.

Apparatus for supplying cooling fluid

Abstract: An apparatus for circulating cooling fluid through a plurality of cooling modules for cooling electronic components, such as IC'S or LSI'S. A plurality of cooling fluid supply systems are independently connected to the respective cooling modules. Each of the supply systems includes a fluid line connected to a single tank containing cooling fluid and is provided with a pump and a heat exchanger, so that the cooling fluid in the tank is circulated through the respective cooling modules and returned to the tank, in which the cooling fluid is then mixed.

Waste heat recovery system

Abstract: There is provided a waste heat recovery system characterized by a boiler assembly including a heat recovery steam generator through which exhaust gas is flowed The boiler assembly includes a high temperature steam tube heat exchanger, or superheater, and at a location downstream therefrom a water tube boiler An ammonia gas injector is utilized for injecting ammonia into the exhaust gas stream which injector is located upstream of the superheater and water tube boiler Finally, there is provided a low temperature selective catalytic reduction unit located downstream of the low temperature water tube boiler or evaporator This arrangement simplifies retrofitting of existing heat recovery systems

Fuel cell stack cooling system

Abstract: Fuel Cell stack coolant water is processed by moving the two-phase water/steam coolant exhaust through a steam separator wherein the water phase is separated from the steam phase. The water phase is then moved through a heat exchanger where its temperature is lowered to a subcooled level which is below the coolant operating temperature in the stack. A flow control valve is associated with the coolant heat exchanger to regulate water flow through and/or around the heat exchanger depending on the temperature of the water which leaves the steam separator. By subcooling the coolant before it reenters the stack, a lessening of electrolyte loss through evaporation is achieved. By eliminating steam condensation as a form of system heat rejection, system engineering is simplified and construction costs are lowered.

A survey of oscillating flow in Stirling engine heat exchangers

Abstract: Similarity parameters for characterizing the effect of flow oscillation on wall shear stress, viscous dissipation, pressure drop and heat transfer rates are proposed. They are based on physical agruments and are derived by normalizing the governing equations. The literature on oscillating duct flows, regenerator and porous media flows is surveyed. The operating characteristics of the heat exchanger of eleven Stirling engines are discribed in terms of the similarity parameters. Previous experimental and analytical results are discussed in terms of these parameters and used to estimate the nature of the oscillating flow under engine operating conditions. The operating points for many of the modern Stirling engines are in or near the laminar to turbulent transition region. In several engines, working fluid does not pass entirely through heat exchangers during a cycle. Questions that need to be addressed by further research are identified.

Flexible hose heat exchanger construction with combination locating and thawing wire

Abstract: A flexible hosing for circulation of a heat transfer fluid to effect heat exchange within a concrete or other type of slab. An inner wall comprising nylon, rayon or other similar material forms an inner wall of the hosing to resist corrosive attack by the heat transfer fluid. A locator wire is embedded within the hosing for transmission of a locating signal so that the position of the hosing within the slab may be accurately determined. The wire may also serve as an electrical resistance heating element should the heat transfer fluid become frozen, or should it be desired that the heat exchange system be operated without an external boiler or other heat source.

Constant temperature fryer assembly

Abstract: A constant temperature fryer assembly having a conveyor for cooking food in oil at a predetermined constant temperature. The fryer is constructed having an external heat exchanger for heating the oil. Oil is removed from the fryer, pumped through the heat exchanger and then pumped back into the fryer through a series of aperatures. The aperatures are positioned in the fryer to provide predetermined temperature at various positions along the conveyor, thereby maintaining a controlled cooking environment.

System for measuring multiphase fluid flow

Abstract: Water, oil and gas mixtures such as produced from oil and gas wells are analyzed as to the proportionate content of each component in the total mixture by calorimetric processes in systems which separate the gas from the fluid mixture, withdraw a sample of the liquid mixture and subject the sample at a given or determined flow rate to a heat exchange process. The remaining main flow of the liquid mixture is also subjected to a heat exchange process and a heat balance is calculated for the flowstream based on the change in temperature of main liquid flowstream and the change in temperature of the heat exchange medium. The processes are carried out on the main flowstream by interposing a heat exchanger in the flowstream or by reinjecting into the flowstream a measured amount of heat exchange fluid such as separated water or crude oil. The components of the liquid portion of the flowstream may be analyzed by passing a liquid sample through a heat exchanger to measure the heat loss or increase of the sample together with mass flow and volumetric flowmeters or by passing the liquid sample flowstream through a source of microwave electromagnetic energy and measuring the dielectric properties of the fluid mixture.

Device and method for engine cooling

Abstract: A device for engine cooling includes at least one mechanical coolant pump driven by the engine to be cooled and at least one electric coolant pump controlled by an electronic switching device being provided in at least one cooling circuit of an engine to be cooled. The conveying capacity of the electric pump is set as a function of operating variables of the engine to be cooled and of further variables, while the mechanical pump is designed for a basic conveying capacity. In the coolant circuit a heat exchanger which is operated as a radiator, the cooling capacity of which can be altered with the aid of a radiator blind and of a fan, is arranged in a first coolant path. An additional heat exchanger, the waste heat of which is used for heating purposes or for further engine cooling, is arranged in an additional coolant path or in a separate coolant circuit.

Fluidized bed reactor having an integrated recycle heat exchanger

Abstract: A fluidized bed reactor in which a recycle heat exchanger (40) is located adjacent the furnace (4) of the reactor with each enclosing a fluidized bed and sharing a common wall including a plurality of water tubes. A mixture of flue gases and entrained particulate materials from the fluidized bed in the furnace are separated and the flue gases are passed to a heat recovery area (8) and the separated particulate material to the fluidized bed in the recycle heat exchanger (40). The bed materials in the fluidized bed in the recycle heat exchanger are passed to the fluidized bed in the furnace. Steam is generated, superheated and reheated in the heat exchange surfaces, including water wall tubes, in the furnace, the recycle heat exchanger, and the heat recovery area.