Showing papers on "Heat exchanger published in 1974"

Solar heat collector

Abstract: An elongated solar heat collector is formed by means of a heat exchanger having two thin-walled tubes arranged coaxially of one another, a cylindrical, transparent heat shield positioned coaxially around the tubes and an elongated parabolic reflector mounted to locate the focal axis of the reflector on the axis of the tubes and shield. The outer tube of the heat exchanger has helical corrugations extending along a greater portion of its length and the valleys of the corrugations are made to contact the outer surface of the inner tube so that a helical passageway is defined between the inner and outer tubes. The straight elongated passageway of the inner tube and the helical passageway between the coaxial tubes communicate with one another at one end of the elongated collector so that two fluid flow paths defined by the passageways are serially connected and permit a fluid heat exchange medium such as water to flow in and out of the exchanger. With such construction, solar energy directed from the reflector through the transparent shield heats the water or other medium by conduction when the medium flows in one direction through the inner tube as well as when the water flows in the opposite direction in the helical passageway within the outer tube.

Air conditioning apparatus utilizing solar energy and method

Abstract: An air conditioning apparatus and method are disclosed. The apparatus includes a chemical dehumidifier which employs an aqueous hygroscopic solution of glycol and a solar energy collector for use in regenerating the solution. Air to be conditioned is circulated through a contactor of the chemical dehumidifier, in contact with cooled glycol solution. Concentrated hygroscopic glycol solution is circulated from a regenerator to the contactor, while dilute solution is circulated from the contactor to the regenerator. Energy from the solar collector is transferred to facilitate concentration thereof. In one disclosed embodiment energy from the solar collector is also transferred to the generator of heat-powered refrigeration apparatus, e.g., absorption or rankine engine driven refrigeration apparatus. The condenser of the refrigeration apparatus may operate to heat the glycol solution in the regenerator of the dehumidifier and the evaporator may cool the concentrated glycol solution in the contactor and/or may supply chilled fluid to a heat exchanger for cooling the dehumidified air. In a modified embodiment, a diesel engine drives the refrigeration apparatus. Waste heat from the diesel engine either augments the solar energy for regenerating the glycol solution or regenerates desiccant from a second stage of dehumidification.

Heating and cooling system

Abstract: An environment heating and cooling system comprising a solar collector, heat storage ground well, cold storage ground well and a heat exchange apparatus. Water from a cold storage ground well is heated in the heat exchange apparatus by solar heating fluid heated in a solar collector. The heated water is stored in a heat storage ground well. Water from the heat storage ground well heats the ambient environment when the solar collector requires supplementation. Water from the cold storage ground well is used to cool the ambient environment. In addition, water from both ground wells serves ordinary household purposes as drinking, bathing and the like.

Multiple fluid stacked plate heat exchanger

Abstract: A heat exchanger of a stacked plate design wherein two or more fluids are in heat exchange relationship, comprising two or more independent sets of plates with the fluid passages of one set of plates being interconnected for continuous flow therethrough and the other set of plates being similarly interconnected and interleaved with the first set; and each of the plates in the two or more sets being separated by intermediate fins which serve as secondary heat exchange surfaces

Integrated thermal anti-icing and environmental control system

Abstract: An integrated thermal anti-icing and environmental control system for a gas turbine powered aircraft uses hot high pressure bleed air from the turbine compressor to de-ice the wings and the engine air inlet, and supplies conditioned air for the aircraft cabin. In order to minimize total bleed air requirements and maximize heat recovery, bleed air exhausted from the inlet anti-icing system is passed sequentially through other systems. In this invention, the usual pre-cooler unit and the associated heat sink are eliminated and the pre-cooling function is performed within the inlet anti-icing system, preferably through the use of a double skin heat exchanger contained within the lip of the inlet. One embodiment of this system includes a closed-loop liquid anti-icing system for acoustic rings mounted in the inlet wherein the liquid is heated by passing the bleed air through a heat exchanger mounted immediately downstream of the inlet anti-icing system.

Heat exchange and transport in the environment. Report No. 14

Abstract: Man's thermal discharges are discussed in the context of earth's overall heat balance. Field data from about 20 lakes, rivers and estuaries are analyzed to demonstrate the validity of a simplified and refined theory of surface heat exchange that combines the heat dissipation roles of evaporation, conduction and back-radiation into a single exchange coefficient. The equilibrium temperature concept is used to permit excess temperatures due to thermal discharges to be identified and analyzed. Manual techniques for estimating diurnal and seasonal fluctuations in water temperatures, including effects of ice cover, are exemplified. The role of longitudinal mixing in recirculated cooling lakes is analyzed and discussed. Various theoretical and empirical formulations for thermal plume shapes and trajectories are analyzed and summarized in terms of a general classification of hydrothermal problems and a unifying characterization of temperature distributions.

Heat exchange over a melting snow surface

Abstract: The relative importance of the principal elements of the thermal balance above snow during a period of melting has been evaluated using recent studies of the turbulent transfer in the boundary layer. Several anomalies in the profiles prove the continuing presence, near to the surface, of a thick layer of air apparently re-heated by the radiative flux. It is shown that the upper surface of this \"exchange layer\" ought 10 be considered as the new level for the origin of profiles, and taken as the exchange surface. The importance of nocturnal refreezing has been quantified. Excellent correlations have been found between mean air temperature and total energy balance; they have allowed the establishml,nt of an approximate, non-linear expression for the effective daily ablation of snow as a function of mean air t('mperature. This rela tion gives satisfactory results at high and intermediate altitudes, in horizontal uncovered terrain. The measurements were made in the French Alps at 3 550 m and in Spain at the latitude of Madrid at I 860 m. RESUME. Echanges de cha/eur au-dessus d'une surface de neige ell piriode de fonte. On a evalue I'importan('c relative des principaux elements du bilan thermique au-dessus de la neige en periode de fonte, d'apres cll' recentes etudes sur les transferts turbulents dans la couche limite. Diverses anomalies dans les profils prouvent la presence continuellc, pres de la surface, d'une epaissc couche cl'air rechauffee vraisemblablement par k flux radiatif. On a montre que la face superieure de cette \"couche d'echange\" devait e tre consideree comme nouveau plan des origines des profils et prise comme surface d 'echange. L' importa nce du rcgel nocturnc a ete chiffree. On a trouve d'excellentes correlations entre temperatures moyennes de I'air et bilan total d'energie; clles ont permis d'etablir une expression approchee, non lineaire, de I'ablation quotidienne effective de neige en fontion de la temperature moyenne de I'air. Celle relat ion donne des n!sultats sat isfaisants a haute et moyenne altitude, en terrain horizontal et decouverL Les mesures ont ete faites dans ks Alpes frans:aises a 3 550 m et en Espagne sous la latitude de Madrid a I 860 m. ZUSAMMENFASSUNG . Wiirmeaustausch aber einer schmelzellden Schneeoberjliiche. Die Hauptelemente der Warm('bilanz Uber schmelzendem Schnee wurden auf Grund neucrer Untersuchungcn Uber den turbu lentrn Austausch in der bodennahcn Schicht in ihrer relativen Bedeutung bestimm!. Verschicdenc Anomalicn in den Profilen beweisen das sUindige Vorhandensein einer dUnnen Luftsehieht dieht liber der Oberflache, die wahrscheinlich durch den StrahlungsAuss erwarmt isL Es wird gezeigt, dass die obere GrenzAache diest'r \"Austauschschicht\" als neue Ausgangsflache flir Profile be trachte t und als Auslauschflache gcwahlt werden muss . Das Ausmass des nachtlichen Wiedergefrierens wurde zahlcnmassig crfass!. Zwischen der milllcren Lufttcmperatur und der Energie-Gesamtbilanz ergabcn si ch engste Korrelationen; sic crmoglichten dir Ableitung eines nichtlinearen Naherungsausdrucks fUr die tagliche effektivc Schnecablation als Funktion der mittleren Lufttemperatur. Diese Beziehung liefert in grossen und millleren Hohen bci ebenem und offenl'll1 Gelande befriedigende Ergebnisse. Die Messungen fan den in den franzosischen Alpen auf 3 550 III und in Spanien auf der Brei te von Madrid in I 860 m Slall.

Heat exchanger utilizing adjoining fluidized beds

Abstract: A heat exchanger in which a substantially vertical partition divides a housing into at least two adjoining chambers each of which support a bed of particulate fuel material. Air is passed through the beds to promote the combustion of the fuel material and to maintain the chambers at predetermined temperatures. The fuel material in one of the chambers is relatively coarse while the fuel material in the other chamber is relatively fine with the chambers communicating to permit circulation of portions of the fuel between the chambers.

Heating and cooling system utilizing solar energy

Abstract: System using solar energy to heat a fluid in a heat storage tank can be utilized in either a heating mode or cooling mode. In the heating mode, several valves are actuated to cause fluid contained in an internal heat exchanger in the heat storage tank to circulate in series circuit with external heat exchange means in communication with the space to be heated. In the cooling mode, the valves are operated to cause the heated fluid in the internal heat exchanger mounted in the heat storage tank to circulate to a heat exchanger mounted in a refrigerant boiler. As the refrigerant boils, vapors are formed which pass through an ejector. The expanded refrigerant vapors are then condensed to liquid in a fan cooled condenser and a portion of the liquid is returned to the refrigerant boiler by a refrigerant circulating pump. The remaining portion of the refrigerant liquid leaving the condenser is delivered to an evaporator which is located in heat exchange relationship with brine or other cooled liquid in a cold storage tank. The surface of the refrigerant in the evaporator is in communication with the ejector. Cooling of the evaporator refrigerant takes place as a result of its vapor pressure being lowered by the vacuum produced in the ejector by the expansion of the vapors from the boiler as they pass through it. The lowered vapor pressure of the refrigerant liquid in the evaporator causes it to boil at a lower temperature, thereby drawing heat from the brine. A heat exchanger in the cold storage tank is connected in series circuit with the external heat exchange means in the space to be cooled.

Air conditioning process

Abstract: A process for open-cycle air conditioning which affords economy of external power both with respect to cost and energy consumption by providing a low-temperature heater and a high-temperature heater for regenerating the sensible heat exchanger and desiccant when the apparatus is used for cooling and the enthalpy exchanger when the apparatus is used for heating. The power source for the low-temperature heater can utilize solar energy, waste boiler heat, waste process heat, nuclear reactor heat and the like. The power source for the high-temperature heater can be an open flame burner or other conventional heater.

Hot/cold applicator system

Abstract: Heat transferring liquid is pumped by a peristaltic pump from a reservoir through a heat exchanger to a disposable applicator pad through flexible conduits. The heat exchanger is provided with thermoelectric diodes which, under control of electronic circuitry, may absorb heat from or transfer heat to the liquid. Further, the control circuitry permits adjustment of the temperature of the applicator pad, whether hot or cold.

Heat exchanger with rectification effect

Abstract: In a heat exchanger comprising a plurality of first heat-transfer elements (A) for a fluid of higher temperature and second heat-transfer elements (B) for a fluid of lower temperature joined alternately and adjacently and a suitable number of appropriately shaped fins disposed within said elements and wherein the heat exchange is performed between the fluid (a) of higher temperature and the fluid (b) of lower temperature and at least the fluid (a) is changed in phase during the heat exchange, the improvement of providing such a heat exchanger with the ability to rectify the condensate from the fluid (a) and to recover the rectified liquid, wherein the fins in the lower part of the element (A) are so arranged that the fluid (a) entering from a port into the element (A) flows upwards smoothly with contact with the liquid condensed from the fluid (a) at the upper part of the element (A), which flows down through the heat exchanger. The condensed liquid flows down through the fins and is taken out from a port provided at the lowest part of the element (A). Accordingly, condensation of a gaseous fluid and rectification of the resulting condensate are both performed with high efficiency in the same apparatus.

Air separation process and system utilizing pressure-swing driers

Abstract: A cryogenic air separation system is described in which pressure-swing adsorption driers are used to remove virtually all of the moisture from the feed air prior to the passage of the feed air stream through reversing heat exchangers which remove the carbon dioxide. The reversing heat exchangers are regenerated by at least one outgoing product nitrogen stream, while the adsorption driers are regenerated by all or a portion of a low pressure stream withdrawn from the low pressure column the composition of which may be rich in either nitrogen or oxygen depending upon whether the volume of product nitrogen or oxygen is to be maximized. A portion of this low pressure stream may be recovered as a dry product stream, while an additional stream of high purity product oxygen may also be recovered.

Energy conservation unit

Abstract: Disclosed is an energy conservation system for utilizing the waste heat from an air conditioner or refrigeration system to heat water. The system includes a heat exchanger coupled in the output of the compressor of the air conditioner or refrigeration system and to a water reservoir for effecting heat transfer. A pump is interposed between the water reservoir and the heat exchanger for circulating the water. A temperature sensor thermally coupled to the water and electrically coupled to the pump is provided for rendering the pump inoperative when the temperature of the water in the reservoir is at or above a preselected temperature. A temperature operated valve is interposed between the heat exchanger and the reservoir, such that only water heated to a predetermined temperature is delivered to the reservoir.

Heat transfer measuring device

Abstract: A device is provided for measuring the efficiency of a heat exchanger. The device comprises a plurality of temperature sensors, a plurality of difference means and calculation means. The difference means are each responsive to a different pair of the temperature sensors to provide a signal representative of the temperature difference between the location of the sensors. The calculation means is responsive to the signals from the difference means for generating a signal representative of the efficiency of the heat exchanger. The signal is representative of either the heat transfer coefficient or the fouling factor in a heat exchanger.

Method of cooling air and apparatus intended therefor

Abstract: A method and apparatus provides conditioning of an air stream by cooling in a regenerative heat exchanger having two groups of channels separated from one another by walls through which heat exchange occurs. The air stream to be conditioned flows through one group of channels while an auxiliary air stream flows through a second group of channels the walls of which comprise wettable material maintained wet by means of water which is caused to evaporate by the auxiliary air stream to result in cooling. The wettable material provides a substantially stationary liquid layer maintained in the channels of auxiliary air flow so that evaporation takes place directly from the walls separating the two groups of channels to obtain high heat exchange efficiency. The wettable material may be wick-like absorbing material layers which eliminate the requirement of continuously flowing large quantities of water so that the evaporative surfaces may be rewetted intermittently and kept wet over a period of time prior to subsequent rewetting. This is accomplished by providing an excess amount of water. In addition, intensive rinsing of the evaporative surfaces may take place to remove dust particles and mineral deposits occurring in the water. The auxiliary air stream may be split off from the stream of air to be conditioned before and/or after the air stream has been conditioned by cooling to provide greater efficiency.

Method and apparatus for storing a medium heated by solar energy

Abstract: A heating system has means for directing heat only to a portion of a medium for storing heat which portion is at a temperature below that to which heating means then heats the medium. The system then functions to store heat in the medium during periods of less-than-maximum heating of the medium without degrading the temperature of a higher-temperature portion of the medium. The system has particular utility with a solar heat collector from which the available heat varies with the intensity of the solar energy. Heat is then collected in the portion of the medium during periods of marginal solar energy intensity without degrading the higher temperature of another portion of the medium heated to a higher temperature during a prior period of greater solar energy intensity. In a specific embodiment the system has three compartments for separating a fluid heat-storing medium into portions, a pump supplying the fluid to a solar heat collector, and a pump supplying the fluid to a heat exchanger for heating a house. The means for directing heat to a portion of the medium then direct fluid heated in the collector to a compartment of fluid at a temperature nearest below that to which the solar heat collector then heats the fluid. The pump supplying fluid to the collector withdraws fluid from a compartment at a lowest temperature to maximize the thermal efficiency of the collector and exchanger.

Heat recovery system for space heating and for potable water heating

Abstract: In a hot water heating system for both space heating and potable water heating, a plurality of space heaters, a furnace and a source of potable water, a plurality of pipes connected between the heaters and the furnace and between the source of potable water and the furnace to circulate the water for heating, the plurality of pipes including heat recovery pipes in heat exchange relationship with the hot flue gasses in the flue of the furnace to heat the water for the space heaters and to preheat the potable water, and controls operatively connected to the pipes to first effect circulation of water through the heat recovery pipes and through the space heaters and then to effect circulation of water through the heat recovery pipes to heat the potable water dependent upon demand, to thus substantially increase the economy and efficiency of operation of the hot water heating system.

Solar heat absorbing system

Abstract: Improved solar heat recovery is provided through the use of a system which embodies passing air or other gaseous stream with entrained black body particles from a solar heating zone to a particle separation zone such that a heated particle stream can be passed to a heat exchange zone to impart heat to water or other heat exchange medium. The resultant cooled particles are subsequently remixed with the gaseous stream being separately discharged from the particle separation zone such that a recombined stream is recirculated to the solar heating zone to provide a continuous operation.

Heat exchanger tube

Abstract: Heat exchanger tube wherein the outside and/or inside surfaces of the tube have a heat exchange enhancement pattern formed in them. The heat exchange enhancement pattern does not extend through the full wall thickness. It is possible for the heat exchange enhancement pattern to include longitudinally extending variations in the type of enhancement. A process and apparatus for forming the tube provide for patterning metal strip and then forming the strip into the shape of a tube and then joining the longitudinally extending edges of the strip to form the complete tube.

Compact heating and cooling system

Abstract: A compact absorption refrigeration unit has a central mounting core containing a generator about which substantially all of the components of the refrigeration system are mounted in a predetermined configuration. The generator has heat transfer fins secured to its surface which have a predetermined configuration that allows the fins and generator to absorb heat at the optimum rate at which heat can be transferred thereto without damage to the fins. The unit also includes an evaporator having a centrally positioned reservoir and a helical passageway providing a flow path for a heat exchange medium and containing a fluted helical heat exchanger tube which provides a countercurrent refrigerant, thereby to chill said heat exchange medium. In one embodiment of the invention the unit is provided with a compact boiler for use in heating the heat exchange medium, thereby permitting the unit to be selectively operated for both heating and cooling.

Solar heat pump

Abstract: A heating and cooling system which uses heat derived from solar collectors to operate a heat engine which provides operating power to drive a heat pump/air conditioning system and including capability to operate either partly or wholly on supplementary energy sources such as an oil or gas furnace or electric power, and employing positive displacement heat engine and compressor units.

Process for preparing heat exchanger tube

Abstract: Heat exchanger tube wherein the outside and/or inside surfaces of the tube have a heat exchange enhancement pattern formed in them. The heat exchange enhancement pattern does not extend through the full wall thickness. It is possible for the heat exchange enhancement pattern to include longitudinally extending variations in the type of enhancement. A process and apparatus for forming the tube provide for patterning metal strip and then forming the strip into the shape of a tube and then joining the longitudinally extending edges of the strip to form the complete tube.

Extended fin heat exchanger panel

Abstract: A heat exchanger panel formed from two superimposed plates, at least one of which is folded on itself longitudinally to create a series of outwardly extending open-looped fins, serving as multiple ducts to provide free passage and direct prime heat-exchanging fluid contact along the entire inner wall surface of the fins.

Hydronic heating system

Abstract: A hydronic heating system includes a heat exchanger, a container, and a micro-wave heating means associated with the container for heating water therein. The container and heat exchanges are connected by a closed circulation loop which includes a storage tank between the container and heat exchanger and a by-pass means to allow flow of water from the heat exchanger to flow directly to the storage tank without passing through the container. A valve is provided in the circulation loop downstream of the by-pass means. A temperature sensor in the storage tank controls operation of a switch in circuit with the valve and micro-wave heating means. When the temperature of the water in the storage tank is below a predetermined temperature, the switch is closed to simultaneously activate the micro-wave heating means and to open the valve to allow water to flow from the heat exchanger into the container. When the water temperature in the storage tank is above the predetermined temperature, the switch is opened to simultaneously de-activate the microwave heating means and to close the valve to divert water from the heat exchanger through the by-pass means into the storage tank. The by-pass means is provided with a check valve and a pump circulates the water through the closed circulation loop.