US3398785A

US3398785A - Combination heating and cooling unit

Info

Publication number: US3398785A
Application number: US555128A
Authority: US
Inventors: Robert V Anderson
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-06-03
Filing date: 1966-06-03
Publication date: 1968-08-27
Anticipated expiration: 1985-08-27

Description

R. V. ANDERSON l Papa/'afar' Cona/2052!' Filed June M u VY/M E COMBINATION HEATING vAND COOLING UNIT Aug. 27, 1968 Hed/h C yc/e Empa/'dof' INVENTOR @abe/vf K #nde/25er? United States Patent 3,398,785 COMBINATION HEATING AND COLING UNIT Robert V. Anderson, 707 Stemmons Tower East, 2700 Stemmons Freeway, Dallas, Tex. 75207 Filed June 3, 1966, ser. No. 555,123 9 Claims. (Cl. 165-29) ABSTRACT OF THE DISCLGSURE A temperature contnol unit having `in combination with a compressor and liuid restriction means, a first and a second heat exchanger and a selective valve operable to cause the rst `heat exchanger to operate as a condenser when the unit is used as a heater and as an evaporator when the unit is used as a cooler, with the second heat exchanger operating as an evaporator when the unit is used as a heater and as a condenser when the unit is used as a cooler. A third heat exchanger adds heat to the iiuid owing to the restriction means and decreases the heat content of the uid owing through the restriction means. A bypass for the first and second heat exchangers, while acting as a condenser, continues to supply heat to the third heat exchanger when uid flows through the bypass. A heater for raising the temperature of the fluid when required is provided with a fuel control that is operably coupled with a variable restrictor for restricting the iiow of fluid from the selective valve to the compressor.

This invention relates to mechanical refrigeration apparatus land equipment for utilization therewith for improving the over-all eiiiciency and usefulness thereof.

Generally speaking, mechanical refrigeration units operate by taking advantage of the Well known physical phenomenon that the boiling temperature of a liuid increases as the pressure exerted on the fluid is increased. Thus, it is possible to store the heat extracted from a relatively low temperature substance in a refrigerant as latent heat by vaporizing the refrigerant in the presence of the substance at a pressure sufficiently low to cause the boiling temperature of the refrigerant to be below the temperature of the substance, and then compress the vaporized refrigerant so that the heat stored therein may be extracted therefrom by passing the same in heat exchange relationship with a material having a temperature lower than the condensation temperature of the refrigerant at its compressed level, thereby causing the refrigerant to expel its latent heat. To complete the circuit, it is the usual practice t-o expand the high pressure relatively warm liquid refrigerant across an orifice or other restriction means such as an expansion valve, thus producing low pressure liquid to be returned to the evaporator.

As the liquid from the condenser is expanded across the restriction means, a certain amount of the iluid will be vaporized or flashed to thereby cool the remaining liquid down to the boiling temperature established by the pressure level existing in the evaporator. A method and apparatus for increasing the efficiency of a mechanical refrigeration system by minimizing the ashing of refrigerant downstream from the restriction means is described in my Patent No. 3,214,929, entitled Refrigeration Unit Having Superheated Gas Feedback and issued Nov. 2, 1965. This was a definite step forward in the art by providing a mechanical refrigeration unit and method for operating the same with increased eiciency and utility.

However, certain inherent problems are still existent in the operation of such devices, particularly when the evaporator and condenser are subjected to widely varying temperatures. Additionally, I have found that, by adequately controlling such an apparatus, the same may be 3,398,785 Patented Aug. 27, 1968 eiiiciently utilized for both heating and cooling. A mechanical refrigeration apparatus may be used for heating a substance by subjecting the same to indirect heat exchange with a high pressure, Irelatively high temperature refrigerant with a boiling point higher than the temperature of the substance to be heated and thus the heat stored as latent heat in the refrigerant'can be expelled into the substance.

The heat given up by the condensing refrigerant may be regained thereby by expanding the same across restriction means to a lower pressure and evaporating the refrigerant in the presence of an atmosphere which is re1- atively yWarmer than the refrigerant, yet may be substantially colder than the substance being heated. Generally, the foregoing heating cycle is highly advantageous in heating a house in the winter where the substance is indoor air `at a temperature of approximately F., and thus the condensation of the refrigerant can take place at a pressure level resulting in a condensation point of say F. The evaporator will be outdoors and exposed to a winter temperature and thus the pressure exerted on the refrigerant in the evaporator must be sutliciently low to establish a boiling point which is below the temperature of the outdoor air. If the same apparatus utilizing the same refrigerant is to be used for cooling, as would be necessary in the summertime, the evaporator will extract heat from the room at -a temperature level of say 50 to 60 F., and condensation must take place in the presence of outdoor air which may be as warm as F. in some instances.

Thus, it is necessary, in order to achieve maximum efliciency and utilization of ya mechanical refrigeration unit, to adapt the same adequately to perform in a suitable manner while causing the condensation of the refrigerant to occur automatically over a wide range of temperatures, depending on the temperature of the environment surrounding the condenser and causing the evaporator to operate over a similarly wide range of temperatures existent in the atmosphere surrounding the evaporator.

It is, therefore, the primary object of the instant invention to provide a combination heating and cooling system having a pair of heat exchangers, a compressor and restr1ct1on means in `a closed circuit for compressing a fluid, condensing the compressed iiuid at a relatively high ternperature, expanding the condensed iluid and evaporating the same at a relatively low temperature, wherein one of the exchangers may be selectively supplied with either a relatively warm condensible vapor, or a relatively cool, vaporizable liquid under controlled conditions so that the atmosphere surrounding that heat exchanger may be selectively and effectively heated or cooled by exchanging heat lwith a fluid undergoing change of state at an appropriate temperature.

As a corollary to the foregoing object, it is an important aim of the instant invention to provide a system as described wherein valve means are provided to the end that either of the heat exchangers may be selectively coupled into the circuit, downstream from the compressor to serve as a condenser, lwhile the other heat exchanger is coupled into the circuit upstream from the compressor to serve as an evaporator.

It is a very important object of the instant invention to provide a third heat exchanger for such a system subcoolinig the relatively warm liquid iiowing from the condenser and to superheat at least a portion of the decreased pressure liquid leaving the restriction means so that the flashing of refrigerant downstream `from the restriction means may be minimized and the superheated portion may be recombined with vaporized refrigerant slugs of liquid leaving the evaporator to thereby vapoiize such slugs.

Another very important object of the instant invention is the provision of bypass means downstream from the restriction means whereby a portion of the subcooled liquid refrigerant may be split off from the refrigerant stream entering the evaporator, vaporized and superheated in the third exchanger to thereby subcool the liquid refrigerant iiowing from the condenser, and then rejoined with the fluid leaving the evaporator upstream from the compressor to vaporize any liquid remaining therein.

Still another important object of the present invention is to provide means in heat exchange relationship with the relatively cool, low pressure liquid downstream lfrom the restriction means so that, when the system is being used to heat an atmosphere by condensing a relatively warmer vapor in heat exchange relationship therewith, and the environment surrounding the evaporator is too cold to eiiectively transfer heat thereinto to vaporize a sui'licient quantity of cool, low pressure liquid, the heat exchange means may be energized to supplement the action of the evaporator.

Yet another important object of the instant invention is the provision of a variable restriction in the system downstream from the bypass and the placement of the heat exchange means in the bypass downstream from the third heat exchanger to the end that when the evaporator becomes ineffective, and the heat output of the condenser is insutiicient to meet the demand, the variable restriction may be closed to lforce a larger quantity of low pressure uid past the heat exchange means.

A further important object of the instant invention is to provide a bypass for the condenser so that when the heat being gained by the vaporizing liquid in the evaporator is less than the heat being shed by the condensing va-por in the condenser, a portion of the vapor may be permitted to remain uncondensed, yet still flow through the system, to provide additional heat to said third heat exchanger so that the portion of refrigerant downstream of the restriction may be more highly superheated and then recombined with partially vaporized refrigerant, leaving the evaporator to vaporize completely such refrigerant, whereby the conditions of the lsystem are stabilized.

In the drawing:

FIGURE l is a diagrammatic view of a combination heating and cooling unit embodying the principles of the instant invention and effecting a heating cycle; and

FIG. 2 is a diagrammatic view of the same unit effecting a cooling cycle.

A combination heating and cooling system or unit embodying the principles of the instant invention, is broadly designated by the numeral 10. Generally speaking, a unit such as will have its greatest utility when used for controlling the temperature of the atmosphere of a iirst space 12 at a preset level by extracting heat therefrom, or adding heat thereto as required by the heat content of the atmosphere of space 12. Space 12 will normally be an inside room of a building or the interior of an automobile; however, space 12 may take the form of any enclosed volume which is desirably heated in one instance and cooled in another.

A second space 14, having an atmosphere with an uncontrolled atmosphere, is selected for adsorbing waste heat from the unit '10 when heat must be extracted lfrom the atmosphere of space -12 and for supplying makeup heat to the unit 10 when heat must be added to the atmosphere of space 12. Generally, space 14 will be the environment surrounding the enclosed space 12 such as the outdoors and thus, the temperature of the atmosphere of space 14 will be determinative of whether heat must be extracted from or added to the atmosphere of space 12. For example, it may be desirable to control the temperature of the atmosphere of space 12 at 70 F. As the temperature of the atmosphere of the surrounding space 14 drops below 70 F., the temperature of the atmosphere of space 12 will likewise tend to drop as a result of heat transfer through the walls of the building or automobile defining space 12. Thus, heat must be supplied to space 12 for holding the temperature of the atmosphere thereof at 70 F. AOn the other hand, if the temperature of the atmosphere of space 14 were to rise above 70 F., the temperature of the atmosphere of space 12 will tend to rise. In this event, heat must be extracted from the atmosphere of space 12.

A tirst heat exchanger 16 is disposed within space 12. The exchanger 16 has a pair of

connections

18 and 20 and a chamber 22 communicating the

connections

18 and 20, for permitting flow of fluid therethrough. The chamber 22 is disposed in heat exchange relationship with the atmosphere of space 12, is operable as a condenser to permit a high pressure vaporous refrigeration medium to condense by adding heat at a high temperature level to the relative colder atmosphere of space 412, and is operable as an evaporator to permit a low pressure liquid refrigeration medium to vaporize by extracting heat at a low temperature level from the relatively warmer atmosphere of space 12.

A second heat exchanger 24 is disposed Iwithin space 14 and has a pair of

connections

26 and 28 and a chamber 30 communicating the

connections

26 and 28. Exchanger 24, like exchanger 16, is operable as either a condenser or an evaporator, depending upon the temperature levels of the atmospheres of spaces 12 and -14.

The pair of

heat exchangers

16 and 24 are identical from a functional standpoint and may take any form which is suitable for use with a mechanical refrigeration unit.

Valve means 32 in the nature of a pair of 4-

way valves

34 and 36 is coupled with the

connections

18, 20, 26 and 28 and has a high pressure vapor tube 38, a high pressure liquid -conduit 40, a low pressure liquid pipe 42, and a. low pressure vapor line 44. Each

valve

34 and 36 has a

respective port structure

46 and 48 which are linked together by linkage means 50 and shiftable therewith to selected positions. In one position, designated by the numeral 32a in FIG. 1, the valve means 32 is selectively connecting the chamber 22 of exchanger 16y between tube 38 and conduit 40, and `at the same time is selectively connecting chamber 30 of exchanger 24 'between pipe 42 and line 44.

In another position, designated by the numeral 32b in FIG. 2, the valve means 32 is selectively connecting the chamber 22 of exchanger 16 between pipe 42 and the line 44, while at the same time is selectively connecting chamber 30 of exchanger 24 between tube 38 and conduit 40.

A compressor 52 is connected to tube 38 and line 44. Compressor 52 may take any form which is suitable for compressing a Vaporons refrigerant and is operable for drawing low pressure vaporous refrigeration medium from line 44, receiving the medium and exerting pressure thereon, and discharging the now high pressure vaporous medium into tube 38.

A receiver 54 is preferably connected in conduit 40 for receiving high pressure liquid medium and for stabilizing the operation of the unit 10 in a manner well known to those skilled in the art. Restriction means in the nature of an expansion valve 56 is coupled to the conduit 40 and pipe 42. Means 56 may take the form of a restricted oritice, a capillary or any other device operable to create a substantial pressure drop at controlled conditions; however, for purposes of illustration and for providing excellent control, a temperature controlled expansion valve is included in the unit 10. The valve 56 has a temperature bulb 58 disposed to sense the temperature of the refrig` erant in a portion 44a of line 44 which presents an inlet to compressor 52. A capillary tube 60 couples bulb 58 with the control means of valve 56. Valve 56 is operable for receiving high pressure liquid refrigerant medium from conduit 40, checking the ow of medium from conduit 40 sufficiently to maintain a high pressure therein, decreasing the pressure of the refrigerant, and discharging the low pressure refrigerant into pipe 42.

It is to be noted that irregardless of whether valve means 32 is shifted to position 32a or to 32b, compressor 52, tube 38,

structures

46 and 48,

chambers

22 and 30,

connections

18, 20, 26, 28, conduit 40, valve 56, pipe 42, and line 44, are interconnected and present a closed circuit 62 for ow of fluid through the system 10.

A bypass 64 is provided in system 10 and coupled to the circuit 62 for communicating pipe 42 downstream from valve 56 and the compressor inlet 44a in bypassing relationship to whichever of the

exchangers

16 or 24 has the

chamber

22 or 30 thereof connected between pipe 42 and line 44 as determined by the selective positioning of

structures

46 and 48. A third heat exchanger 66 has a uid passage 40a serving as a part of conduit 40 and a fluid channel 64a serving as a portion of bypass 64 and provides means for placing the passage 40a and the channel 64a in heat exchange relationship with respect to one another.

Another heat exchanger 68 presents means in the nature of a coil 70 in heat exchange relationship with another portion 64b of bypass 64 disposed downstream from the portion 64a. Coil 70 has an inlet 72 and an outlet 74 for directing a flow of Huid through coil 70. It is to be under, stood that exchanger 68 is illustrated in the preferred position therefor in the drawing; however, from a strictly functional standpoint, exchanger 68 could be effectively utilized if it were positioned in line 44 rather than in bypass 64 or in line 44a after junction 78 and upstream of bulb 58.

A Variable restrictor or throttle valve 76 is disposed i line 44 upstream from compressor inlet 44a and upstream from a juncture 78 joining bypass 64 with line 44. A control in the nature of a valve 80 is installed in inlet 72 to coil 70 and linkage means 82 is connected to valve 76 and valve 80 for opening valve 80 as valve 76 is closed and vice versa. The inlet side of valve 80 is connected to means (not shown) containing a supply of fluid providing a heat source and outlet 74 is connected to an exhaust system for returning the fluid to the supply means or exhausting the same.

A conduit 84 is connected to circuit 62 for communicating tube 38 and conduit 40 in bypassing relationship to whichever of the

chambers

22 or 30 is connected between tube 38 and conduit 40. Means in the nature of a pressure sensitive valve 86 is disposed in conduit 84 for varying the ow therethrough. It is to be understood that valve 86 could as well be temperature controlled or flow controlled; however, for purposes of illustration, pressure control has been selected.

OPERATION In operation, system may be utilized for heating or cooling the atmosphere of space 12. Viewing FIG. l, valve means 32 has been selectively positioned in position 32a for effecting a heating cycle. The temperature of the atmosphere of space 12 (indoors) is preferably controlled at approximately 70 F., while the temperature of the atmosphere of space 14 (outdoors) is somewhat colder, say 32 F. for purposes of illustration. Compressor 52 draws relatively cold, low pressure, vaporous refrigerant from compressor inlet 44a, exerts sufficient pressure thereon to cause the refrigerant to condense at approximately 90 F. (or any temperature sufliciently higher than 70 F. to effect ecient transfer of heat in exchanger 16), and discharges the high pressure vaporous refrigerant into tube 38. The vaporous refrigerant will be superheated durmg the compression thereof to a temperature in excess of 90 F. The high pressure, high temperature, vaporous refrigerant flows through tube 38, through structure 46, and into chamber 22 through connection 18. In chamber 22, the refrigerant having a pressure level suiciently high to establish a condensation point therein of approximately 90 F. is brought into heat exchanging relationship with the F. atmosphere of space 12 and, therefore, the refrigerant is condensed and the latent heat given up thereby is transferred into the atmosphere of space 12.

The condensed high pressure refrigerant having a temperature of approximately 90 F. leaves chamber 22 through .connection 20, passes through structure 48 and into conduit 40 for passage through receiver 54 and into restriction means 56 Where the pressure of the liquefied refrigerant is decreased sufficiently to cause a boiling point of approximately 10 F. to be achieved in the refrigerant (although the temperature of 10 F. has been arbitrarily selected, any temperature lower than the said 32 F. temperature of the atmosphere of space 14, which is suiciently below 32 F. to result in efficient heat transfer between the atmosphere and the refrigerant may be utilized).

The low pressure liquid refrigerant is now passed through pipe 42, through structure 48, and into chamber 30 through connection 26 where heat from the 32 F. atmosphere of space 14 may be transferred into the low pressure refrigerant in chamber 30 having a boiling point of approximately 10 F. and stored therein as latent heat by boiling the refrigerant at 10 F. The low pressure, vaporized, relatively low temperature refrigerant is drawn out of chamber 30 through connection 28, then through structure 46 and into line 44 and the compressor inlet 44a by the action of compressor 52.

Exchanger 66 operates in a manner explained in mv above-mentioned patent to prevent ashing in pipe 42 and minimize the existence of liquid refrigerant in compressor inlet 44a. A portion of the low pressure liquefied refrigerant having a boiling temperature of approximately 10 F. is split off from the remaining refrigerant passing through pipe 42 and passed through bypass 64 where it is brought into heat exchanging relationship with the relatively warmer high pressure liquid refrigerant (90 F.) passing through conduit 40. The high pressure liquid passing through conduit 40 is thereby cooled to a temperature closely approximating 10 F., while the portion of the low pressure refrigerant passing through bypass 64 is vaporized at 10 F. and then superheated sufficiently to serve as a source of heat for vaporizing any liquid leaving chamber 30 through line 44 when the two streams are joined at juncture 78.

Because of the nature of the utilization of the unit 10, there is a possibility that the temperature of the atmosphere of space 14 will become so low (for example 10 to 15 F. below zero) that it is no longer practical to reduce the pressure of the refrigerant across valve 56 sufciently to obtain a boiling point below the temperature of the atmosphere of space 14 while still maintaining a pressure level downstream from the compressor sufficient to cause the refrigerant to condense in chamber 22 at a temperature above the 70 F. temperature of the atmosphere in space 12. Also, if the outside humidity in space 14 is sufliciently high, ice will accumulate on the external surfaces of exchanger 24 and the heat-transferring ability of the exchanger may become impaired sufficiently to preclude the transfer of heat in effective quantities. Whenever either of these possibilities occur, auxiliary heat inlet means valve is opened to permit the relatively high temperature heating fluid to pass lthrough coil 70. This fluid may be at a temperature as low as approximately 30 F. and still be capable of transferring heat into the low pressure, relatively low temperature refrigerant.

It is to be appreciated that the heat of compression gained by the refrigerant in the compressor 52 is available for use during the heating cycle and, therefore, even though exchanger 24 is ineffective to provide heat, exchanger 68 would not be used as an auxiliary heat source unless the demand of heat in exchanger 16 exceeds the heat gained during compression.

Valve 76 may be partially closed and thus valve 80 partially opened through the action of linkage means 82, and a relatively larger quantity of refrigerant will be forced through bypass 64 and through heat exchanger 68 where the refrigerant will be heated by transfer of heat from the source flowing through coil 70. It is to be understood that the source may be the exhaust gases from ,an automobile or from any internal combustion engine serving to drive compressor 52, or could be water; however, the temperature of the water leaving outlet 74 would have to be closely controlled to guard against freeze-up in the coil 70. Likewise, exchanger 68 could take the form of a relatively small electric heater. The position of exchanger 68 is favorable for highly eicient transfer of heat from a moderate to even low temperature heat source and, therefore, large quantities of heat may be added to the refrigerant While using a relatively small heat exchanger.

Viewing FIG. 2 of the drawing, valve means 32 has been selectively positioned in position 321; for effecting a cooling cycle relative to the space 12. The temperature of the atmosphere of space 12 (indoors) is preferably controlled at approximately 70 F., while the temperature of the atmosphere of space 14 (outdoors) is somewhat warmer, say 100 F. for purposes of illustration.

The chamber 30 of exchanger 24 will receive the high -f pressure vaporous refrigerant from the compressor and condense the same at a temperature of approximately 120 F. This temperature, again, has ben chosen as illustrative and any temperature higher than the 100 F. temperature of the atmosphere of space 14 may be used so long as the temperature differential is sufficient to cause eicient heat transfer.

The condensed high pressure liquid is passed from chamber 30 through connection 26, through structure 48, through conduit 40, and across valve 56 where the pressure of the refrigerant is decreased sufficiently to cause a boiling point of approximately 50 F. to be achieved in the refrigerant in chamber 22. The refrigerant vin chamber 22 is caused to boil by heat exchange with the 70 F. atmosphere of space l2, and the vaporized refrigerant is passed through connection, through structure 46, through line 44, and back to the compressor inlet 44a.

Thus, a cooling cycle is established in system 10. The heat exchanger 66 operates in substantially the same manner as described above and in my above-mentioned patent. As the temperature of the atmosphere of space 12 is cooled to more closely approach the temperature of the boiling refrigerant in chamber 22, the quantity of heat transferred into the refrigerant becomes less and, therefore, a smaller quantity of refrigerant is evaporated. Thus, compressor 52 will tend to reduce the pressure on chamber 22 as the refrigerant seeks a boiling temperature sufficiently low to again cause an amount of refrigerant substantially equal to the capacity of the compressor to be vaporized.

As the pressure in chamber 22 decreases, a corresponding decrease in the pressure downstream from cornpressor 52 in tube 38, will be experienced. To avoid the occurrence of this phenomena, the pressure sensitive valve 86 is adjusted to open when the pressure in tube 3S falls below some certain predetermined pressure. It is to be noted that the temperature of the condensed refrigerant leaving chamber 30 will be related to the pressure existing in chamber 30 and, therefore, the valve could be temperature sensitive. Likewise, as the pressure of the system decreases, the capacity of the compressor will experience a corresponding decrease and the valve 86 could be effectively controlled by sensing the flow of liquid through conduit 40. In any case, as the pressure of the system decreases, valve 86 is opened to allow a quantity of the relatively warm, high pressure, vaporous refrigerant to bypass channel 30 and, in this manner, the amount of heat extracted from the refrigerant in chamber 30 can be made to correspond with the amount of heat extracted from the atmosphere of space 12 and into the refrigerant in chamber 22 while still maintaining an eicient pressure level in the system.

It is to be understood lthat the

valves

76 and 80 may be operated manually or automatically. Valve 76 is to be closed and valve 80 opened as the temperature in the atmosphere of space 14 decreases to a point where effective heat gain therefrom cannot be achieved in the refrigerant vaporizing in chamber 30. Thus, a temperature device sensitive to the atmosphere in space 14 may be utilized to determine when valve 76 should be closed yand valve 80 opened and vice versa. Likewise, valve means 32 may be selectively positioned either manually or automatically. Generally, the temperature of the atmosphere in space 12 is preselected and whenever the temperature of the atmosphere of space 14 falls below that temperature, valve means 32 is shifted to position 32a as shown in FIG. 1. Conversely, when the temperature of the atmosphere of space 14 rises above the temperature selected for the atmosphere of space 12, valve means 32 should be shifted to position 32b as shown in FIG. 2.

It would be expected that when a combination heating and cooling system was instantaneously switched from heating to cooling, or vice versa, unstable operation would result for a time :because the heat content of the iluid in the new evaporator would be too high and the heat content of the uid in the new condenser would be too low. However, it has been found, unexpectedly, that when a heating and cooling unit embodying the -principles of the instant invention is instantaneously switched from heating to cooling, or vice versa, unstable operation does not occur to any substantial extent. It is believed that this result is obtained because the refrigerant boiling oif of the liquid in the new evaporator, as the latter seeks the proper temperature level, is backed out of the evaporator and through bypass 64. Thus excess heat from the fluid in the evaporator side of the system can be transferred into the fluid in the condenser side of the system in the heat exchanger 66, and thus the pressure levels in the system are rapidly adjusted to proper levels.

When the principles of the instant invention are utilized in the design of a mechanical refrigeration apparatus, the apparataus may be more eciently used at all conditions and, therefore, the range of effective use is broadened.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a combination heating and cooling system:

a first heat exchanger disposed within a first space in heat exchange relationship to the ambient atmosphere thereof;

a second heat exchanger disposed within a second space in heat exchange relationship to the ambient atmosphere thereof,

the temperature of said atmospheres normally being diiferent, each heat exchanger having a chamber for ilow of a fluid therethrough;

a closed circuit for flow of said Huid coupled with the chambers of said heat exchangers;

a compressor in said circuit for receiving said uid and exterting pressure thereon;

restriction means in said circuit checking the flow of said fluid therein to maintain the pressure exerted thereon =by said compressor;

valve means in said circuit shiftable to selected positions for effecting in said system, a heating cycle to raise the temperature of the atmosphere of the lirst space, and a cooling cycle to lower the temperature of the atmosphere of the iirst space,

said valve means being coupled in said circuit with the compressor, the chambers and the restriction means whereby,

in one of said positions for effecting said heating cycle, said valve means directing the uid for flow from the compressor, through the valve means and through the chamber of the first heat exchanger, thence through the valve means and then through the restriction means, then through the valve means and through the chamber of the second heat exchanger, through the valve means and thereupon through the compressor, and whereby,

in another of said positions for effecting said cooling cycle, said valve means directing the fluid for flow from the compressor, through the valve means and through the chamber of the second heat exchanger, thence through the Valve means and then through the restriction means, then through the valve means :and through the chamber of the first heat exchanger, through the valve means, and thereupon through the compressor;

a conduit coupled with said circuit for bypassing the ,chamber of said first heat exchanger when the valve means is in said one position to effect said heating cycle, and for bypassing the chamber of said second heat exchanger when the valve means is in said other position to effect said cooling cycle; and

means in said conduit for varying the flow of fluid therethrough.

2. In a combination heating and cooling system:

the temperatures of said atmospheres normally being different, each heat exchanger having a chamber for flow of a fluid therethrough;

a closed circuit for flow of said fluid coupled with the chambers of said heat exchangers;

a compressor in said circuit for receiving said fluid and exerting pressure thereon;

restriction means in said circuit checking the flow of said fluid therein to maintain the pressure exerted thereon by said compressor;

valve means in said circuit shiftable to selected positions for effecting in said system, a heating cycle to raise the temperature of t-he atmosphere of the first space, and a cooling cycle to lower the temperature of the atmosphere of the first space,

in one of said positions for effecting said heating cycle, said valve means directing the fluid for flow from the compressor, through the valve means and through the chamber of the first heat exchanger, thence through the valve means and then through the restriction means, then through the valve means and through the chamber of the second heat exchanger,

through the valve means and thereupon th-rough the compressor, and whereby,

in another of said positions for effecting said cooling cycle, said valve means directing the fluid for flow from the compressor, through the valve means and through the chamber of the second heat exchanger, thence through the valve means and then through the restriction means, then through the valve means and through the chamber of the first heat exchanger, through the valve means, and thereupon through the compressor; and

a third heat exchanger for adding heat to the fluid owing to the compressor and for decreasing the heat content of the fluid flowing through said restriction means,

said third heat exchanger having a fluid passage in the circuit interconnecting the valve means and the restriction means upstream of the latter, and

a bypass coupled with said circuit, Ihaving a position thereof in heat exchange relationship to said passage,

said bypass interconnecting the downstream side of said restriction means with the compressor inlet.

3. The invention of claim 2:

and means in heat exchange relationship with said bypass downstream of said portion for heating the fluid flowing through the bypass when the valve means is in said one position to effect said` heating cycle, and when additional heat is required in the refrigerant flowing through said first heat exchanger.

4. The invention of claim 2:

and a variable restrictor in said system between said compressor inlet and the valve means downstream of the latter for restricting the flow of fluid from said valve means,

said bypass discharging into the system downstream of said restrictor.

5. The invention of claim 3:

a variable restrictor in said system between said compressor inlet and the valve means downstream of the latter for restricting the flow of fluid from said valve means,

said bypass discharging into the system downstream of said restrictor;

and a control for said means in heat exchange relationship with said bypass responsive to variances in said restrictor where-by to increase the heat output of said means in heat exchange relationship with said bypass upon increased fluid flow in the bypass.

6. In a combination heating and cooling system:

a second lheat exchanger disposed within a second space in heat exchange relationship to the ambient atmosphere thereof;

the temperature of the atmosphere of the first space lbeing normally higher than the temperature of the atmosphere of the second space,

each heat exchanger having a chamber for flow of a fluid therethrough;

a closed cir-cuit `for flow of said fluid coupled with the chambers of said heat exchangers;

restriction means in said circuit checking the flow of said fluid therein to maintain the pressure exerted thereon by said compressor,

said circuit being coupled in the system for flow of said fluid from the compressor through the chamber of said first heat exchanger, then through said restriction means, thence through fthe chamber of the second heat exchanger and thereupon through the compressor;

a third heat exchanger for converting liquefied fluid flowing to the compressor into a saturated vapor and for minimizing flash gas downstream from said restriction means,

said third heat exchanger having a fluid passage in the circuit interconnecting the chamber of the first heat exchanger and said restriction means, and

a bypass coupled with said circuit, having a portion thereof in heat exchange relationship to said passage,

said bypass interconnecting the downstream side of said restriction means with the compressor inlet; and

a conduit coupled with said circuit for bypassing the cham-ber of said first heat exchanger, said conduit having means therein for varying the flow of fluid therethrough whereby the heat content of the fluid is supplied to the third heat exchanger either from the compressor or from the chamber of the first heat exchanger.

7. In a combination heating and cooling system:

a first heat exchanger disposed within a first space in heat exchange relationship to the ambient atmosthereof;

a second heat exchanger disposed within a second space in heat exchange relationship to the ambient atmosyphere thereof,

the temperature of the atmosphere of the iirst Space being normally higher than the temperature of the atmosphere of the second space,

each heat exchanger having a chamber for flow of a uid therethrough;

a closed circuit for flow of said fluid coupled Awith the chambers of said heat exchangers;

a compressor in said circuit -for receiving said uid and exerting pressure thereon;

restriction means in said circuit checking the ow of said fluid therein to maintain the pressure exerted thereon by said compressor,

said circuit being coupled in the system for ow of said fluid from the compressor through the chamber of said first heat exchanger, then through said restriction means, thence through the chamber of the second heat exchanger and thereupon through the compressor;

means in the system and in heat exchange relationship with the low pressure liuid flowing from the restriction -means to said compressor for heating said low pressure fluid; and

a third heat exchanger for converting liquefied iluid flowing to the compressor into a saturated vapor and for minimizing iiash gas downstream from said restriction means,

said third heat exchanger having a fluid passage in the circuit interconnecting the chamber of the rst heat exchanger and said restriction means, and

a -bypass coupled with Said circuit, having a portion thereof in heat exchange relationship to said passage,

said bypass interconnecting the downstream side of said restriction means with the compressor inlet,

said low pressure iluid heat exchange means being in said bypass, downstream from said portion.

8. The invention of claim 7:

a variable restrictor in said circuit between the inlet to the chamber of said second heat exchanger and the compressor for producing a pressure drop in the fluid flow from the chamber of said second heat exchanger,

said bypass discharging into said system downstream of said restrictor;

and a control for said heating means responsive to variances in said restrictor whereby to increase the heat output of said heating means upon increased fluid ow in said bypass.

9. In combination:

a pair of heat exchangers, each having a pair of connections and a chamber between the connections for changing the state of a heat storing medium as a consequence of heat being exchanged between said medium and a substance undergoing change of enthalpy;

valve means coupled with said connections and having a high pressure vapor tube, a high pressure liquid conduit, a low pressure liquid pipe and a low pressure vapor line, said valve means having port structure shiftable to selected positions for selectively oonnecting the chamber of one of said exchangers between said tube and said conduit while connecting the chamber of the other of said exchangers Ibetween said pipe and said line, and for selectively connecting the chamber of said one of said exchangers between said pipe and said line while connecting the chamber of said other of said exchangers between said tube and said conduit;

a compressor connected to said tube and said line for drawing low pressure vaporous medium from the latter, exerting pressure on the medium, and discharging the high pressure vaporous medium into said tube;

restriction means coupled to said pipe and said conduit for receiving high pressure liquid medium from the latter, decreasing the pressure on the medium, and discharging the low pressure liquid medium into said plpe,

whereby the heat exchanger -chamber connected between said tube and said conduit is permitted to operate as a condenser and the heat exchanger chamber connected between said pipe and said line is permitted to operate as an evaporator,

and whereby a chosen one of said exchangers is permitted to selectively heat and cool the substance in heat exchange therewith;

a bypass communicating said pipe and said line in bypassing relationship to the heat exchanger selectively permitted to operate as an evaporator; and

means placing a portion of said bypass in heat exchange relationship with a part of said conduit, whereby to subcool the liquid medium flowing to the restriction means for minimizing flash gas downstream from the latter and to vaporize and superheat the medium flowing through said bypass for vaporizing liquid medium flowing from the evaporator.

References Cited Anderson 62-117 ROBERT A. OLEARY, Primary Examiner.

55 CHARLES SUKALO, Assistant Examiner.