Showing papers on "Heat exchanger published in 1981"

Thermal energy storage and regeneration

Abstract: The newest techniques and theories covering the design and management of thermal energy storage systems in the areas of heat recovery and in circumstances where energy availability does not coincide chronologically with demand are presented. Techniques that predict the performance of sensible heat storage units in a broad range of operating conditions and methods for designing energy storage units for a variety of applications are covered comprehensively. The single blow problem of gas passing through heat-storing packing continuously in one direction is discussed. Solutions to this problem facilitate the control of the drying or cooling of beds of grain, other food stuffs, and industrial granular or powder products. These same solutions are applicable to the crucial issues of heat storage capabilities of particular construction in buildings and thermal stores built into solar collectors. Detailed information is included about counterflow regenerators including finite conductivity and nonlinear models. New concepts in computational methodology, parallel flow regenerators, heat storage exchangers, and packed beds are also covered. The optimization of prediction of heat storage systems and useful engineering correlations for thermal and hydraulic aspects of storage unit design are presented and explained in detail.

Chapter 2 Measurement of Thermal Balance of Man

Abstract: Publisher Summary The thermal environment of man begins at the skin surface and extends outward to the surrounding media, which consist of the air that he breathes; the clothing that he wears; man-made sources of heat and cold necessary for health and comfort; heat, cold, and humidity caused by weather; and exposure to solar radiation All these factors are characterized by temperature, or they in some way affect the heat transfer from the skin surface by radiation, convection, conduction, or evaporation Heat balance equations describing human heat exchange by radiation, convection, evaporation, and conduction from the skin surface with the thermal environment are discussed in the chapter The environmental variables in the basic heat balance equation that must be measured are the ambient air temperature, the mean radiant temperature or effective radiant field, the ambient water vapor pressure or humidity, air movement as it affects the convective and evaporative heat loss, and clothing insulation The physiological variables in the heat balance equation are skin temperature, skin wettedness, mean body temperature, metabolic energy consumption, and the rate of external work

Solar heating system

Abstract: A solar heating system including a flat plate solar collector having a heat absorber woven basket fashion across a riser grid system containing suitable flow medium for being heated by the solar radiation. A heat exchange column is coupled to the riser grid system for extracting the heat from the flow medium to provide it to heating, hot water, and the like. The heat exchange column includes a number of continuous coils placed within a tank and having a circulating loop pass a liquid from the bottom of the tank to the top of the tank where it will flow over all of the coils transferring heat from one coil to the other. The flow is controlled by means of the load demand and the available supply of heat. Excess heat is stored in a heat storage system having a plurality of blocks of Glauber salt containing matrix material through which pass pipes containing the heated liquid. One of the riser grid systems can be utilized as part of an absorption cycle air conditioning system by passing the heated fluid medium into a regenerator placed adjacent to the collector to effectively form a distillation process. In place of the liquid solar collector, an air heating solar collector is also provided.

Earth storage structural energy system and process for constructing a thermal storage well

Abstract: A geothermal space conditioning and water heating system for a building structure comprises a battery of serially coupled thermal storage wells. Each well includes a dual concentric thermal conduction tube having an external circumference and an integrated earth interface and substantially moisture impervious clay platelet transition surrounding and at least double the tube circumference. The thermal storage battery has a cold port and a hot port maintained at a temperature greater than the cold port. A space conditioning arrangement is provided in which thermal transport fluid passes through a fan-driven radiator. A reversible heat pump has a radiator conditioned air coupled first heat exchanger and a downstream radiator fluid coupled second heat exchanger. A second heat pump has a first heat exchanger in thermal communication with a hot port coupled hot water heater and a cold port coupled second heat exchanger. A transient storage tank provides a time averaged uniform transport fluid temperature. Valving allows reversal of fluid from the hot and cold ports to and from the transient storage tank and the space conditioning arrangement as determined by multiple temperature sensors determining output states of a controller. The geothermal storage wells are established by circulating a mud in a well to stabilize the hole, running a conduit in the well and thereafter reverse-circulating a sand/gravel slurry through the conduit thereby packing the region between the conducting tube and the earth interface.

Compact storage of seat and coolness by phase change materials while preventing stratification

Abstract: While many materials and additives which will melt and freeze at various temperature levels for storing and releasing large amounts of heat thereby per unit volume have been disclosed, the packaging of these materials with suitable non-corrodible long-lasting heat exchange structures has been cumbersome and expensive The present invention provides an inexpensive, high performance, non-corrodible thermal storage method and system adapted for use with heat storage materials of various compositions and adapted for use over a wide range of temperatures, including a heat exchanger which provides for phase change to occur approximately simultaneously throughout the volume of the entire storage mass and provides for the sites at which the phase change is occurring to be approximately uniformly distributed throughout the volume of the heat storage material Problems of thermal expansion, stratification and sub-cooling are eliminated Thermal storage methods and systems embodying the present system may advantageously be used for off-peak storage of electric refrigeration, cooling and heating as well as solar heating and other applications

Fluid catalyst regeneration process and apparatus

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke contaminated fluid catalyst. The process comprises a high temperature coke combustion zone, a catalyst disengagement zone and an external heat removal zone comprising a shell and tube heat exchanger. Catalyst is cooled by passing it through the shell side of the heat exchanger with a cooling medium through the tube side. A mixture of coke contaminated catalyst, oxygen containing gas, and cool regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is passed through the heat exchanger. This rate is adjusted by adjusting the difference in catalyst head between the catalyst inlet and outlet of the heat exchanger and thus the hydraulic driving force which effects catalyst circulation through the heat exchanger.

Air fractionation by pressure swing adsorption

Abstract: Improved oxygen recovery in the operation of a pressure swing adsorption system for air fractionation is obtained by passng the air, freed of water and CO 2 , through an adsorbent bed maintained at elevated temperature throughout the cycle and which is selective for retention of nitrogen, and consequent withdrawal of an oxygen-rich primary effluent product. In a preferred embodiment ambient air is passed through a pretreater section providing an adsorbent bed for removal of water and carbon dioxide. The thus purified air is compressed with consequent rise in temperature and then only partly cooled down by exchange with cooler desorbed and purged nitrogen-rich gas products withdrawn from the main adsorbent beds. These nitrogen-rich products thus heated by the exchange are employed in regenerating a water and carbon dioxide laden bed of the pretreater section. While the adsorption-desorption is operated in a pressure swing cycle, the pretreater section is operated in an independent thermal swing cycle. Alternatively, the feed air may be compressed prior to its introduction into the pretreater and the thus generated heat utilized by heat exchange for heating the purified air effluent to be fractionated.

Fresh air breathing mask with exterior heat exchanger

Abstract: A typical embodiment of the invention provides a sturdy, lightweight, inexpensive and comfortable warmer for fresh breathing air. An heat exchanger that is sufficiently flexible to conform with the shape of a wearer's scalp is secured to the wearer's head by means of a pullover cap. In this way the heat exchanger takes advantage of the great heat dissipating capabilities of the human head in order to warm fresh breathing air on its way from the atmosphere to the wearer's nose mask.

Windmill power apparatus and method

Abstract: Air compressed by a windmill-driven compressor is stored as liquid in an underground cryogenic insulated tank. Pressurized air released from the tank is vaporized by a refrigerant circuit, heated, and used to operate an air motor which drives an electrical generator. Heat of compression extracted by compressor coolant heats vaporized air entering the motor and heats water stored in a ground-level tank located directly above the cryogenic tank. Solar and fossil fuel heating circuits further heat vaporized air entering the motor. Motor exhaust is used as a coolant in refrigeration circuits. The inlet and outlet conduits to the cryogenic tank are arranged to effect heat exchange. The windmill has a vertical axis rotor with curved blades mounted in a vaned housing.

Cooling system for the electrical generator of a turbofan gas turbine engine

Abstract: A cooling system 44 for an electrical generator 42 is disclosed. The cooling system rejects excess heat to the engine fuel through a primary heat exchanger 46 and at low fuel flow rates, supplementarily rejects heat to fan air at a secondary heat exchanger 48 located remotely from the fan duct 30. In one embodiment, the secondary heat exchanger is disposed in a nacelle fan compartment 14. In another embodiment, the secondary heat exchanger is disposed in a nacelle core compartment 16.

Method and means for in situ repair of heat exchanger tubes in nuclear installations or the like

Abstract: A method for the in situ repair of heat exchanger tubes in major heat exchanger equipment is disclosed in which supercooled sleeves are inserted into cracked heat exchanger tubes and are expansion-fitted firmly against the inner walls of the cracked tubes. In order to prevent premature expansion of the relatively long, small diameter sleeves during insertion, the tubes may be filled with a heat sink material which is removed following insertion. The insertion is also preferably accomplished very rapidly by means of a power-actuated ram which maintains the sleeve at its low temperature until the very last moment before insertion. Various guide means and plug means for the sleeve are described. The technology is also indicated as being applicable to the temporary sealing of defective tubes by using a removable plug in the form of a closed-end sleeve into whose interior a cryogenic agent can be selectively introduced during insertion and removal.

Air cycle refrigeration system

Abstract: An air cycle refrigeration system (10) for cooling and ventilating an enclosure such as an aircraft cabin (15) includes a circulation heat exchanger (145) for absorbing heat from air within the cabin, a sink heat exchanger (120) for delivering the heat absorbed from the cabin air to exhaust air from the system's turbine (80) and for melting ice in the exhaust air A heat exchange liquid circulates through both heat exchangers in a single loop (100) The circulation heat exchanger (145) may be located in the interior of the cabin (15)

Charge air cooler mounting arrangement

Abstract: A charge air cooler is provided for mounting within the intake manifold of a combustion engine. The charge air cooler comprises a heat exchanger core formed by a plurality of relatively lightweight heat transfer elements defining a first flow path for charge air prior to ingestion of the charge air by the engine and a second flow path for a coolant in heat transfer relation with the charge air. The heat exchanger core supports at least one transversely extending rigid mounting sleeve for receiving a mounting bolt passed through a bolt-receiving hole in the intake manifold to secure the charge air cooler within the intake manifold.

Method and apparatus for supplying cooling liquid to a storage battery

Abstract: A method and apparatus for providing a cooling liquid to the heat exchanger in a storage battery mounted on a vehicle for driving the vehicle, wherein the liquid is to be supplied to the battery at an inlet temperature which varies in a time-based relationship. The liquid to be cooled is obtained from the battery itself in a recirculative system located generally outside the vehicle. In accordance with this method and apparatus, the liquid returned from the vehicle mounted storage battery is divided into first and second portions, the first of these portions is cooled at a preselected cooling rate, thereafter, the cooled first portion and the uncooled or bypassed second portion are recombined to provide the liquid supplied to the battery heat exchanger. The ratio of the first and second portions is adjusted in accordance with a time-based relationship wherein the temperature within the battery is intentionally changed during a charging cycle.

Downhole thermoelectric refrigerator

Abstract: Cooling of electronic components, positioned downhole in a high temperature environment in a deep well, is achieved by a thermoelectric cooling system within a long vacuum insulated dewar flask which encompasses the electronic components and the cooling system. The electronic components are directly mounted on the cold plate of the cooling system and will be cooled down to a temperature well below the downhole ambient temperature. A long vapor phase heat transfer pipe and a heat exchanger, which is connected to the pipe's upper end and is immersed in the well fluid, convey heat from the hot plate of the cooling system to the fluid and to the downhole environment which will function as a heat sink, the hot plate temperature being greater than the ambient temperature.

Liquid Droplet Radiators for Heat Rejection in Space

Abstract: A radiator for heat rejection in space is described which utilizes a stream of liquid droplets to radiate waste heat. The large surface area per mass makes the liquid droplet radiator at least an order of magnitude lighter than tube and fin radiators. Generation and collection of the droplets, as well as heat transfer to the liquid, can be achieved with modest extensions of conventional technology. Low vapor pressure liquids are available which cover a radiating temperature range 250-1000 K with negligible evaporation losses. The droplet radiator may be employed for a wide range of heat rejection applications in space. Three applications - heat rejection for a high temperature Rankine cycle, cooling of photovoltaic cells, and low temperature heat rejection for refrigeration in space illustrate the versatility of the radiator.

Thermal performance of the wet surface plastic plate heat exchanger used as an indirect evaporative cooler

Abstract: A mathematical model of the plate heat exchanger (PHE) cooling unit has been developed and solved using a digital computer. The equations of temperature distribution on each plate in a counterflow PHE cooling unit are derived using an energy balance analysis. The results are presented in the form of numerical values of the ''overall effectiveness'' of the heat exchanger. 12 refs.

Influence of Fouling Biofilms on Heat Transfer

Abstract: In heat exchange equipment, fouling biofilm formation causes a significant energy loss by increasing heat transfer resistance. This paper describes experiments which quantify the influence of fouling biofilms on heat transfer resistance under controlled laboratory conditions. Experimental results compare well with a rather simple mathematical model employing friction factor, biofilm thickness, wall temperature, bulk temperature, and fluid properties as inputs. Limitations of the experimental apparatus and mathematical model are discussed

Thermoelectric environmental chamber

Abstract: A portable, lightweight thermoelectric environmental chamber includes insulative side walls, an insulative bottom and an insulative cover that is hingeably connected to one of the walls. A handle is attached to the upper surface of the cover. A thermoelectric unit includes a thermoelectric heat pumping device disposed between an internal heat exchanger disposed inside the thermal compartment of the environmental chamber and an external heat exchanger disposed outside of the thermal compartment. An external blower continuously forces outside air along the surface of the external heat exchanger when the thermoelectric environmental chamber is turned on. An internal blower is controlled by a momentary switch that turns the internal blower on when the cover is closed. A shroud encloses the internal blower and guides air in close proximity to the internal heat exchanger and recirculates air in the compartment to maintain a uniform temperature in the thermal compartment when the cover is closed. A port is provided in one of the walls to allow electrical communication or other types of communication between a device or substance being thermally tested in the thermal compartment and a location outside of the environmental chamber.

Fouling test apparatus

Abstract: A fouling test apparatus comprising a cylindrical pressure vessel, means for controlling the temperature of fluid contained in the vessel, cylindrical probe having a metallic surface concentric with the vessel walls and provided with a heater for such surface; stirrer in the form of a rotor open at at least one end and positioned between and concentric with the vessel walls and the probe, and sensor for measuring the temperature of the fluid contained in the vessel and the temperature of the probe surface. The probe simulates a heat exchanger surface exposed to a fouling liquid medium. Deposits accumulate on the heated surface in a similar fashion to an actual system and the parameters which affect fouling are all represented. The probe operates with a constant heat flux. As deposits accumulate, the surface temperature of the probe increases and is used as a measure of the deposit formation. The probe is maintained in a stationary position and the stirrer is not dependent on an electrical feed-through.

Power generator system

Abstract: A combined cycle (Brayton and Rankine) system for generating electrical power is disclosed. A gas turbine directly connected to an electrical generator is powered by compressed heated air, the air heated, after passing through the compressor section of the turbine, by passage through a high temperature gas-to-air heat exchanger through which hot combustion flue gases (by burning a biomass or other fuel) are also passed. The flue gases, after passage through the heat exchanger, are used to generate steam for powering a steam turbine or for other purposes.

Load management control air conditioning system

Abstract: An air conditioning system for providing an air cooling operation during a load phase management shutdown of the air conditioning compressor utilizes a thermally insulated cold water tank for storing chilled water. The water is cooled by a free cooling effect using wet bulb temperature drop of a refrigerant circulating between a secondary coil in a condenser section of the air conditioning system and a heat exchanger in the chilled water tank located below the condenser. The secondary coil in the condenser is cooled by a waterspray which can advantageously be derived from the condensate obtained from the evaporator section during a compressor operation phase of the air conditioning system. The chilled water is supplied to a chilled water coil in an evaporator section to cool the air flow in a chilled water cooling operation when the air conditioning compressor is inoperative during the load management phase of the peak hour of the air conditioning system.

Vehicle exhaust gas warm-up heater system

Abstract: Liquid coolant of a liquid cooling system of an engine in a motor vehicle is heated by using hot exhaust gas emitted by the engine. A heat exchanger transfers heat from the hot exhaust gas to the coolant. A portion of the coolant is transferred from the engine cooling system to the heat exchanger and then back to the engine. A diverter valve actuated by a temperature sensing device diverts the exhaust gas from an exhaust system to the heat exchanger. The temperature sensing device actuates the diverter valve at a predetermined coolant temperature diverting the exhaust gas to the heat exchanger when the coolant is cold and shuts off the flow of the exhaust gas to the heat exchanger when the coolant is sufficiently warm.

Stepped capacity constant volume building air conditioning system

Abstract: An air conditioning system is disclosed in which the air conditioning capacity is stepped to a lower level upon reduced sensible air conditioning demand. The stepped reduction involves both a stepped reduction of blower capacity and a stepped change of the heat exchange fluid flow at the heat exchanger modifying the temperature of the air. Several embodiments are disclosed.

Synthesis gas cooler and waste heat boiler

Abstract: A synthesis gas cooler has concentric water walls to provide for heat transfer to a fluid in the water wall tubes. The inner water wall is concentric with the cooler shell and has a gas tight inlet connection for introducing hot synthesis gas. The inlet is located at the top of the shell. The bottom of the shell contains a body of water for quenching entrained solids which are carried with the synthesis gas, and there is a baffle to direct the flow of synthesis gas back up in the annulus between the two concentric water walls. The annulus has a closed upper end except for an outlet for the synthesis gas which is located near that end of the annulus. Also, there may be soot blowers along the length of the water walls to keep the heat transfer surfaces clean.

Simplified air conditioner

Abstract: The disclosed air conditioner comprises a suction and an exhaust blower connected to a common electric motor and disposed on a suction and an exhaust passageway adjacent to a suction and an exhaust port on the outdoor side respectively. The suction passageway crosses the exhaust passageway in a heat exchanger and is connected to an indoor exhaust port. A humidifier is disposed between the heat exchanger and an indoor suction ports to humidify and cooler the sucked indoor air within the heat exchanger. Also a reclaimable dehumidifier may be disposed adjacent to the suction blower to decrease the humidity of the sucked outdoor air.

Method and apparatus for co-generation of electrical power and absorption-type heat pump air conditioning

Abstract: A method for co-generation of electrical power and air conditioning for structures, such as office buildings, and housing units is disclosed. An internal combustion engine, preferably a diesel, drives an alternator or generator to supply the building electrical load or for reverse sale to a public utility power grid. Heat from engine exhaust gases is recovered by an absorption-cycle heat-pump system. The system is characterized by using only a single external heat exchanger and a single building air conditioning heat exchanger for selectively heating or cooling air in the air conditioning system. Selection of heating or cooling is by reversable valve means for directing heated refrigerant vapor from a heat powered vapor generator either into the inside heat exchanger for heating or to the external heat exchanger for cooling. The valve means simultaneously converts the other heat exchanger to complimentarily receive liquid refrigerant passing through an expansion valve from the first heat exchanger to absorb heat from the air conditioner for cooling, or from the atmosphere for heating. A particular advantage of this arrangement is reduction in both size and complexity of the vapor generation system to satisfy a wide range of loads because control of heat and liquid circulation rate of carrier liquid alone determine "compression" capacity as distinguished from mechanical pumping capacity of vapor compressor heat pumps. Additionally, the absorption cycle permits handling of mixtures of vapor and liquid phases of the refrigerant component without loss of effectiveness, which is likewise not possible with vapor-compression heat pump systems.