US2148415A - Reversible refrigerating apparatus for heating and cooling - Google Patents

Description

Feb. 21, 1939. J. M. LABBERTON REVERSIBLE REFRIGERATING APPARATUS FOR HEATING AND COOLING Original Filed July 13, 1933 2 SheetsSh e-st l \J M 2 mm H r -mwm J S mm 3 o MN 5 x J v \l s ,1 m ullil l hm a 1. L W U .3 3 S W \N .ll *m m vm m mm\ m. 2 q n 2 mm hm mm 3 v 1 MN H W 2 2 2 w hm m m m m INVENTOR JOHN M. Lassen-TON WITNESSES:

BY .621. W

ATTORN'EY' Feb. 21 1939. J, M. LABBEETON 7 2,148,415

REVERSIBLE REFRIGERATING APPARATUS FOR HEATING AND COOLING Original Filed July 13, 1933 2 Sheets-Sheet 2 In In WITNESSES: INVENTOR 7? T JOHNM.LRBBERTON BY GI Q W ATTORNEY Patented Feb. 21, 1939 PATENT OFFICE S Q REVERSIBLE REFRIGERATING APPARATUS FOR HEATING D COOLING John M. Labberton,

Pittsburgh, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application July 13, 1933, Serial No. 680,307

Renewed January 15, 1936 25 Claims.

My invention relates to reversible refrigerating apparatus for heating and cooling, that is, compression refrigerating apparatus operating on the compression refrigeration cycle for cooling and operating on the reverse refrigeration cycle for heating, and it has for an object to provide an improved system of apparatus of this character.

It is a further object to provide an improved piping arrangement for said apparatus.

Another object is to provide a system in which the lubricant entrained in the refrigerant is returned to the compressor and not accumulated in the evaporator.

A further object is to provide improved control means for reversible refrigerating apparatus.

In accordance with my invention, I provide two heat exchangers adapted to function alternatively as condenser and evaporator, respectively, and vice versa. These heat exchangers are of the type providing dry evaporation when functioning as evaporators. Each heat exchanger is provided with an inlet adjacent to the uppermost level of the heat exchanger and with an outlet near the lowermost level. The discharge of the compressor is connected to the inlet of each heat exchanger and its suction is connected to the outlet of each heat exchanger. Other conduit means are provided to convey condensed refrigerant from the outlet end of each heat exchanger to the inlet end of the other heat exchanger.

I also provide control means embodying one thermostat for controlling the cooling action and a second thermostat for controlling the heating action. A control device, such as a two-way switch, is provided for rendering either one of the thermostats operative, so that the apparatus can function only for cooling or only for heating in accordance with the function-for which the valves are set. I may also provide mechanism whereby the control device also effects adjustment of the valves for the function corresponding to the thermostat which is rendered operative.

The above and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application in which:

Fig. 1 is a diagrammatic view of apparatus embodying my invention;

Fig. 2 is a vertical sectional view showing the upper portion of one of the heat exchangers in greater detail;

Fig. 3 shows a modification of a detail;

Fig. 4 is a diagrammatic view of apparatus having a greater degree of automatic control; and

Fig. 5 is a detail view of a modified form of valve-control mechanism.

Referring now to the drawings more in detail,

I show at In a portion of a room of a house which is to be cooled when the temperature therein is higher than desired, as in the summer, and which is to be heated when the temperature is lower than desired, as in the winter. The apparatus includes two heat exchangers H and I2, shown in perspective in Fig. 1, the former being arranged in anysuitable manner known in the art in heat exchange relation with the interior of the room III. For simplicity of illustration, I have shown it as disposed within the room "L. The heat exchanger I2 is arranged in heat exchange relation with a region exterior to the room III, for example, it may be placed outdoors in direct contact with the outside atmosphere.

Each heat exchanger includes a plurality of pipes or coils I3 each having horizontal legs l4 and having its inlet end adjacent the uppermost level of the heat exchanger and its outlet end adjacent the lowermost level of the heat exchanger. Each heat exchanger includes an upper horizontal header Hi, to which the inlet end of each coil I3 is connected by means of an inverted T-shaped fitting l6' which extends downwardly from the header l5, as shown more clearly in Fig. 2. The structure of Fig. 2 is the same as the structure of Fig. 1; except that Fig.

2 shows fins H which are preferably provided on 5 the coil l3 for the purpose of increasing the heatexchanging surface of the coil. The T-shaped fitting also has an inlet I8 for liquid refrigerant, as will be hereinafter described. The header I5 is providedat one end with a vapor inlet IS. The outlet or lower ends of the coils l3 are directly connected to a lower header 20 which has a vapor outlet 2| and a liquid outlet 22.

The apparatusfurther includes a compressor 23 and a motor 24 driving the compressor. The compressor and motor may be disposed in the basement II). A discharge conduit 25 communicates with the discharge or outlet of the compressor and has two branch conduits 26 and 21 communicating with the vapor inlets heat exchangers II and I2, respectively. The branch conduits 26 and 2! are provided with valves 28 and 28 respectively, disposed adjacent the common discharge conduit 25. A return or suction conduit 28 communicates with the suc- 55 IQ of the provides flow tion or inlet of the compressor and has two branch conduits 29 and II communicating with the vapor outlets 2! of the heat exchangers II and I2, respectively. An oil-separator 50 is interposed in the conduit 28, and the oil separated therein is conveyed to the crank case of the compressor through a conduit 5!. Valves 32 and 32' are provided in the branch conduits 25 and II, respectively, adjacent the vapor outlets 2|.

A liquid conduit 33 communicates with the liquid outlet 22 of the heat exchanger ii for conveying liquid refrigerant from the heat exchanger II to the heat exchanger l2 when the former is acting as a condenser for ,heating the room II. The conduit 33 has a liquid receiver 33' interposed therein and communicates with the heat exchanger l2 through suitable expansion valve means for reducing the pressure of the liquid refrigerant. Such expansion valve means may be any means known in the art which of refrigerant from the high pressure portion of the system to the low pressure portion but which restricts such flow so as to prevent equalization of pressures in the two portions of the system. I prefer, however, for the present purpose, to use flow resistance passages of the type known in. the art as capillary tubes. Accordingly, I show capillary tubes 34 extendin between the conduit 33 and the liquid inlet l5 of each coil l3 of the heat exchanger l2. In order to restrict the admission of liquid refrigerant to the evaporator l2 to the amount that can be evaporated, particularly in cold weather, I provide a valve 35 in the conduit 33. The valve 35 may also be used to supplement the capillary tubes 34 in expanding or reducing the pressure of the refrigerant. Thevalve 35 is operated by a control mechanism 36 which includes a bellows 31 into which the pressure in the header I5 is introduced through a conduit 33 and a second bellows 39 communicating with a thermostatic tube 4l, the latter being placed adjacent to the suction conduit 3|. A spring 40 biases the valve 35 toward closed position. The tension of the spring 40 may be adjusted by an adjusting nut 40.

The pressure in the bellows 31 is a function of the saturation temperature of the liquid refrigerant in the evaporator 12 and the pressure in the bellows 39 is a function of the temperature of the vaporized refrigerant exhausted from heat exchanger I2. The difference of these pressures is, therefore, a measure of the degree of superheat of the exhausted refrigerant, and by controlling the admission of liquid refrigerant to maintain substantially a predetermined degree of superheat, the return of unvaporized liquid refrigerant to the compressor is avoided. Control mechanisms of this type are known in the art.

There is also interposed in the conduit 33 a valve 42 for the purpose of shutting oif all flow through the conduit when thecompressor is shut down and when the heat exchanger 12 operates as a condenser. The valve 42 is biased to closed position by a spring 43, and is adapted to be opened by. an electro-magnet 44, which is controlled as hereinafter described.

A liquid conduit 45 is connected to the liquid outlet 22 of the heat exchanger l2 for conveying liquid refrigerant to the heat exchanger II. when the latter is operating as an evaporator, as in the summer. The conduit 45 also has, a liquid receiver 45' interposed therein and communicates with the coils l3 of the heat exchanger I I through suitable expansion valve means, preferably cap- -ductor 58, and the other,

iilary tubes 34 connected to the liquid inlets l8, similarly to the heat exchanger l2. A hand-set valve 45 is provided in'the conduit 45 adjacent the capillary tubes 34 for supplementing the controlling or expanding action of the capillary tubes, whereby said controlling or expanding action may be varied. The conduit 45 is also provided with a valve 41 which is biased to closed position by a spring and adapted to be opened by a magnet 49.

The control mechanism for the apparatus includes a thermostat 5| for summer operation, adapted to close a pair of electrical contacts 52 in response to a predetermined maximum temperature within the room l0, and a thermostat 5|" for winter operation, adapted to close a pair of contacts 53 in response to a predetermined minimum temperature within the room i0. One contact of each of the pairs of contacts 52 and 53 is connected through a conductor 54, which includes the winding of a relay 56, to one line conductor 55.

A two-blade, double-throw switch 51, when in the right hand position designated S, connects the other contact 52 to the line conductor 55, and when in the left hand position designated W, connects the other contact 53 to the line conductor 55.

One terminal of each of the electro-magnets 44 and 48 is connected to the line conductor 55. The switch 51, when in the position S, connects the other terminal ofthe electro-magnet 49 to the line conductor 55, and when in the position W, connects the other terminal of the electromagnet 44 to the lineconductor 55, in each case through the contacts of the relay 55. One terminal of the motor 24 is connected to the line conthrough the contacts of the relay 55, to the line conductor 55. It is to be understood that conventional motor starting means may be employed.

The operation of the above described apparatus is as follows:

For summer operation, room 10, the valves 28 and 32 are opened, the valves 28" and 32" are closed, and the switch 51 is thrown to the right hand position S. Upon the temperature in the room in exceeding a predetermined value, the thermostat 5l closes its contacts 52 to energize the relay 56, closing its contacts. The latter energizes the electro-magnet 49, opening the valve 41, and also starts the motor 24. The apparatus operates in the usual manner of compression refrigerating apparatus, the heat exchanger l2 functioning as a condenser and the heat exchanger ll functioning as an evaporator to cool the room ID.

The refrigerant compressed by the compressor 23 is conveyed through the conduit 25, the valve 28 and the branch conduit 21 to the vapor inlet 19 of the heat exchanger l2 and is condensed in the coils l3. The condensed refrigerant is discharged through the liquid outlet 22 to the conduit 45. From the latter it passes through the valves 41 and 45, through the capillary tubes 34 and through the liquid inlets [8 to the upper ends of the coils I3 in the heat exchanger H. In the latter, the liquid refrigerant absorbs heat from the air of the room i0 and is evaporated.

The refrigerant flows downwardly through the coils l3, so that the entrained lubricant is carried along with the vaporized refrigerant, which is returned to the compressor through the vapor outlet 2|, the conduits 29 and 23, the valve 32 and the oil separator 50.

that is cooling of the When the temperature in the room ID has been sufliciently lowered, the thermostat 5| opens the contacts 52, deenergizing the relay 5B. The motor an d compressor are stopped, and the valve 41 is closed, thereby preventing further flow of liquid refrigerant into the heat exchanger I I, now the evaporator. It will be noted that the contacts 53 of the thermostat 5| are cut out of circuit bythe switch 51 so that a low temperature in .the room III will not cause operation while the apparatus is set for cooling operation.

When it is desired to set the apparatus for heating operation, as in the winter, the valves 28 and 32 are closed, the valves 28 and 32 are opened. and the switch 51 is thrown to the left-hand position W. As the temperature in the room I decreases to a predetermined minimum temperature, the thermostat closes the contacts 53. The contacts of the relay 56 close, opening the valve 42 and starting the motor and compressor.

Vaporous refrigerant is compressed by the compressor 23, its temperature being thereby raised, as is well known in the art. It is conveyed through the conduit 25, the valve 28 and the conduit 26 and admitted through the vapor inlet l9 to the heat exchanger ll acting as a condenser. In flowing through the heat exchanger I l, the warm compressed refrigerant supplies heat through the coils I3 to the air in the room I0, and is thereby condensed. It is discharged through the liquid outlet 22 and conveyed through the conduit 33, the valves 42 and 35, and the capillary tubes 34, to the liquid inlets l8. of the heat exchanger l2. The pressure of the refrigerant being reduced in the latter, it vaporizes, absorbing heat from the surrounding medium, in this case the outdoor air. The vaporized refrigerant, having now a higher heat content, is returned through.the conduit 3|, the valve 32'', the oil separator 60 and the conduit 28 to the inlet or suction of the compressor.

In passing through the compressor, small quantities of lubricant are entrained in the refrigerant. The lubricant is readily carried withthe refrigerant as long as the latter is in liquid form, but begins to separate therefrom when the refrigi erant is evaporated. In the above described apparatus, the vaporizing refrigerant flows downwardly in both heat exchangers, so that the lubricant is readily carried along. This is also facilitated by the fact that the exchangers are of the type providing dry evaporation; that is, this type has long narrow passages providing forced circulation of the refrigerant which helps to carry the lubricant along. The expression "dry expansion is to be taken as referring to the type of evaporator commonly known by that name in the art, as distinguished from an evaporator of the flooded type, without reference to its accuracy in describing the actual condition of the refrigerant therein.

It will also be noted that the liquid refrigerant admitted through the connections 3 is at a level below the header l5, so that the several quant1- ties delivered by the several capillary tubes 34 to the respective coils I 3 are maintained separate.

The communication between the upper ends ofing and valve arrangement, requiring only four valves to be operated to change from heating to cooling operation, and vice versa. The valves 42 and 41 are automatically operated.

In place of the magnetically operated valves 42 and 41 of Fig. 1, check valves 62, as shown in Fig. 3 may be substituted. In this case, also, the op eration is automatic. The higher pressure in the heat-exchanger functioning as the condenser automatically closes the check valve 52 of that liquid supply conduit, 33 or 45, which communicates with the liquid inlets l8 of said heat exchanger. The check valve 62 in the other liquid supply conduit automatically opens to permit flow of liquid refrigerant from the heat exchanger acting as the condenser to the heat exchanger functioning as the evaporator.

The apparatus shown in Fig. 4 embodies control mechanism having a greater degree of automatic operation; the refrigerating apparatus proper being the same as in Fig. 1.

In this embodiment, the valves '28 28 32 and 32 are automatically adjusted by the switch 51' for cooling operation when the latter connects the cooling control thermostat 5| into service and for heating operation when the switch 51' connects the heating control thermostat 5I into service. The valves 28 28", 32 and 32 are provided with solenoids 63 64 65 and 66" for opening the respective valves and solenoids 53 64*, 65 and 56 for closing the respective valves. One terminal of each of the solenoids 53 54 55 and 66 is connected through conductors 61 to a contact 68 of the switch 51., which contact is connected to the line conductor 58 when the switch is set in the summer or cooling positionindicated at S. One terminal of each of the solenoids 63 64 65 and 66 is connected through conductors 69 to a contact ll which is connected through line conductor 58 when the switch is set in the winter or heating position W. The other terminal of each solenoid is connected to the line conductor 55 through conductors 12.

The magnets 49 and 44 are adapted to be connected to the line conductor 58 through the switch 51 and conductors 61 and 69, respectively, inthe cooling and heating positions, respectively. Both magnets are connected to the line conductor 55 through the contacts of the relay 5G.

The operation of the control mechanism of 4 to a predetermined maximum temperature, the I relay 56 starts the motor 24 and energizes the magnet 49, opening the valve 41. The apparatus now operates to cool the room ID in the manner described in connection with Fig. 1. As the temperature in the room I0 is decreased to a desired value, the contacts 52 are reopened and cooling operation ceases.

When theswitch 51' is thrown to the left or winter position, the solenoids 63 54 65 and 66" are energized opening the valves 28 and 32 and closing the valves 28 and 32 thereby setting the same for heating operation. In this position of the switch 57', the thermostat 5" is connected into service and closes its contacts 53 in response to a predetermined minimum temperature in the room III. The relay energizes the magnet 44 to open the valve 42 and starts the motor 24. Theapparatus now operates to heat the room as described in connection with Fig. 1 until the contacts 53 are reopened as a desired temperature is attained.

In Fig. 5, I show a motor driven form of operating mechanism for the valves 63 to 66. This form is preferably employed in the embodiment of Fig. 4 in which operating mechanism for these valves is only schematically shown in order to simplify and clarify illustration of the system. A split field motor 13 drives a worm I4 meshing with a two part frictional drive gear- 15. The gear 15 comprises an outer part 16 carrying the gear teeth and an inner part 11, which frictionally engages the outer part and is fixed to a rotatable shaft 18 that opens and closes the valve. The frictional engagement is sufficient to transmit the driving force to operate the valve until it is fully opened or closed, when slipping between the inner and outer parts takes place.

The inner and outer parts of the gear I have two pairs of cooperating contacts interposed in the conductors 61 and 69, said contacts being arranged to open the circuit to the motor, when the desired movement of the valve is completed.

nism shown in Fig. 5 is as follows: In the position shown on the drawings, the conductor 61 is connected by the switch 51" to the line conductor 58 but it is open-circuited at the gear wheel contacts, while the gear contacts of the conductor 69 are closed. If the switch 51" is now thrown to the left, a circuit is completed from line conductor 58 through contact H of the switch 51", conductor 69 including its contacts on the gear, one field winding and the armature of the motor and conductor 12, to the line conductor 55. The motor operates to rotate the gear in counterclockwise direction to operate the valve connected to the shaft 18. The valves 28" and 32" are opened and valves 28 and 32 are closed as described in connection with Fig. 4. When the actuation of the valve is completed the shaft 18 and the inner part of the gear are held against further movement. The outer part of the gear continues until the contacts of the conductor 69 the switch is thrown to are moved out of engagement, opening the circuit and stopping the motor. The continued movement of the outer gearpart brings the contacts of the conductor 61 into contact, so that when the right, the circuit through the conductor 61 is completed and the gear is rotated to the right. The valve is now actuated in the ppposite direction until it reaches the end of its travel, when the continued movement of the outer gear part moves the contacts of the conductor 61 out of contact, the contacts of the conductor 69 being meanwhile brought into registry. In this construction, it will be seen that the electric current is cut off when valve 60 actuation is completed.

From the above description, it will be seen that I have provided improved apparatus for heating in winter and cooling in summer and which accomplishes the objects hereinbefore set forth.

while I have shown my invention in several forms, it will.be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without-departing from thesplrit thereof, and I de sire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In reversible refrigerating apparatus for The operation of the valve operating mechaheating and cooling, a heat exchanger adapted to function either as a condenser or as an evaporator of the dry expansion type and comprising a plurality of refrigerant passa es extending from an upper level to a lower leve means for supplying vaporous refrigerant to the passages adjacent the upper level when the heat exchanger is operating as a condenser, means for admitting separate quantities of liquid refrigerant to the respective passages adjacent the upper level when the heat exchanger is operating as an evaporator, means for maintaining said quantities of liquid refrigerant separate adjacent the upper level, and means adjacent said lower level for discharging vaporous and liquid refrigerant.

2. In reversible refrigerating apparatus for heating and cooling, a heat exchanger adapted to function either as a condenser or as an evaporator of the dry expansion type and comprising a plurality of refrigerant passages extending from an upper level to a lower level, a vapor inlet communicating with said passages adjacent said upper level, means for admitting liquid refrigerant, whenthe heat exchanger is op rating as an evaporator, individually to the respective passages at points adjacent to but below the level of communication between the several passages, and outlet means adjacent said lower level.

' 3. In reversible refrigerating apparatus for heating and cooling, a heat exchanger adapted to function either as a condenser or as an evaporator and comprising an upper header having an inlet for receiving refrigerant vapor when the tor of the dry expansion type and having an inlet adjacent its uppermost level for receiving com-.

pressed vaporous refrigerant when functioning as a condenser, a second inlet, for receiving liquid refrigerant when operating as an evaporator, disposed adjacent the uppermost level but below the first inlet so that the liquid refrigerant will not flow out through the first inlet, and an outlet adjacent the lowermost level of the heat exchanger.

5. In reversible refrigerating apparatus for heating and cooling, the combination of a compressor, a first and a second heat exchanger each having an inlet end and an outlet end, means for conveying compressed refrigerant from the compressor selectively to said inlet end of either the first or the second heat exchanger, means for conveying expanded refrigerant selectively from said outlet end of either the first or the second heat exchanger to the compressor, means for conveying refrigerant from said outlet end of each heat exchanger to said inlet end of the other, and means for shutting off commimication through one of the last-mentioned means.

6. In reversible refrigerating apparatus for heating and cooling, the combination of a compressor,'a first and a second heat exchanger each having an inlet end and an outlet end, means for conveying compressed refrigerant from the compressor selectively to said inlet end of either the first or the second heat exchanger, means for conveying expanded refrigerant selectively from said outlet end of either the first or the second heat exchanger to the compressor, means for conveying refrigerant from said outlet end of each heat exchanger to said inlet end of the other, and expansion valve and shut-off valve means in each of the last-mentioned conveying means.

7; Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger both of the dry expansion type and having an inlet end and an outlet end, means for conveying compressed refrigerant from the compressor selectively to said inlet end of either the first or the second heat exchanger, means for conveying refrigerant from said outlet end of each heat exchanger to said inlet end of the other, means for shutting off flow through one of the last-mentioned means, and means'ffor conveying evaporated refrigerant'selectively, from said outlet end of either the first or .7 the second heat exchanger to the compressor.-

8. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and .a second heat exchanger both of the dry type and having an inlet end and an outlet end, means for conveying compressed refrigerant from the compressor selectively to said inlet end of either the first or the second heat exchanger, means for conveying refrigerant from said outlet end of each heat exchanger to said inlet end of the other and for expanding the same, and means for conveying evaporated refrigerant selectively from said outlet end of either the first or the second heat exchanger to the compressor.

9. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger both of the dry expansion type and having-an inlet end and an outlet end, means for conveying compressed refrigerant from the compressor selectively to said in-- let end of either the first or the second heat exchanger, means for conveying refrigerant from said outlet end of each heat exchanger to said inlet end of the other and for expanding the same, means for shutting off flow through one of the last-mentioned means, and means for conveying evaporated refrigerant selectively from said outlet end of either the first or the second heat exchanger to the compressor.

10. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger each of the dry\type and having an inlet end adjacent its uppermost level and an outlet end adjacentits lowermost level, means for conveying compressed refrigerant from the compressor to said inlet end of either heat exchaiger, in which it is condensed, means for conveying condensed refrigerant from said outlet end of each heat exi changer to said inlet end of the other heat exchanger, in which it is evaporated, and means for conveying evaporated refrigerant selectively from said outlet end of either heat exchanger to the suction inlet of the compressor.

11. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger both ofgthe dry type and having a refrigerant passage extending from an upper level to a lower level, means, for conveying, compressed refrigerant from the compressor selectively to' the upper end of the passage in either heat exchanger, means for conveying condensed refrigerantfrom the lower end of the passage in each heat expassage extending from an upper level to a lower level, means for conveying compressed refrigerant from the compressor selectively to the upper end of the passage in either heat exchanger, means for conveying condensed refrigerant from the lower endof the passage in each heat exchanger to the upper end of the passage in the other heat exchanger, expansion valve means for each of the last-mentioned means, and means for conveying evaporated refrigerant selectively. from the lower end of the passage in either heat exchanger to the suction inlet of the compressor.

13. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger each having refrigerant passages extending from an upper level to a, lower level, conduit means communicating with the discharge of the compressor and having branch conduits communicating with the upper ends of the passages in the first and the second heat exchanger, respectively, valve means in each ofsaid branch conduits, conduit means communicating with the suction inlet of the compressor and having branch conduits communicating with the lower ends of the passages in the first and -the second heat exchanger, re-

spectively, valve means in each of said branch tion with the substance to be heated or cooled,

means for conveying compressed refrigerant from the compressor to either heat exchanger, in which it is condensed, then to the other heat exchanger, in which it is evaporated, and back to the compressor, means responsive to a predetermined minimum temperature of said substance for effecting operation of the compressor, means responsive to a predetermined maximum refrigerating apparatus for temperature of said substance forv effecting operation of the compressor, and means for selectively rendering either one of the two last-named meansoperative and the other inoperative.

15. In reversible refrigerating apparatus for heatingand cooling a substance, the combination of a compressor, a first and a second heat exchanger adapted to function as evaporator and I condenser, respectively, or vice versa, the first heat exchanger being in heat-exchanging relation with the substance to be heated or cooled, means for conveying compressed refrigerant from the compressor to either heat exchanger, in which it is condensed, then to the other heat exchanger, in which it is evaporated, and back to the compressor, a first and a second valve for shutting off supply of liquid refrigerant .to the first and to the second heat exchanger, ,respectively, means responsive to a predetermined maximum temperature of said substance for effecting operation of the compressor and for opening the first valve, and means responsive to a predetermined minimum temperature for effecting operation of the compressor and for opening the second valve.

16. The combination defined in claim 15, and further comprising means for selectively rendering either one of the two last-named means operative and the other inoperative.

17. In reversible refrigerating apparatus for heating and cooling a substance, the combination of a compressor, a first and a second heat exchanger adapted to function as evaporator and condenser, respectively, or vice versa, the first heat exchanger being in heat exchanging relation with the substance to be heated or cooled, means for conveying compressed refrigerant from the compressor to either heat exchanger in which it is condensed, to the other heat exchanger in which it is evaporated, and back to the compressor, means responsive to a predetermined maximum temperature of said substance for closing a first pair of electrical contacts to start operation of the compressor,

. means responsive to a predetermined minimum temperature of said substance for closing a second pair of electrical contacts to start operation of the compressor, a first and a second magnetically-opened bias-closed valve for shutting oil supply of liquid refrigerant to the first and to the second heat exchanger, respectively, and a double-throw switch adapted in one position to render the first-mentioned temperature responsive means and the first magnetically-opened valve operable, and in the second position to render the second-mentioned temperature responsive means and the second magneticallyopened valve operable.

18. In reversible refrigerating apparatus for heating and cooling a substance, the combination of a compressor, a first and second heat exchanger adapted to function as evaporator and condenser, respectively, or vice versa, the first heat exchanger being in heat exchange relation with the substance to be heated or cooled, conduit and valve means for conveying compressed refrigerant from the compressor selectively to either heat exchanger, in which it is condensed, then to the other heat exchanger in which it is evaporated, and back to the compressor, means responsive to a predetermined minimum temperature of said substance for effecting operation of the compressor, means responsive to a predetermined maximum temperature of said substance for effecting operation of the compressor, and a control mechanism which is adapted in one condition to render the minimum temperature'responsivemeans operative and the maximum temperature responsive means inoperative and to effect adjustment of the valve means for heating operation of the apparatus, and which" is adapted in a second condition to render the maximum temperature responsive means operative and the minimum temperature responsive means inoperative and to effect adjustment of the valve means for cooling operation of the apparatus.

19. In a reversible refrigerating apparatus for heating and cooling a substance, the combination of a compressor, a first and second heat exchanger adapted to function as evaporator and condenser, respectively, or vice versa, the first heat exchanger being in heat exchanging relation with the substance to be heated or cooled,

conduit and valve means for conveying compressed refrigerant from the compressor selectively to either heat exchanger, in which it is condensed, means for conveying liquid refrigerant from either heat exchanger to the other, a first and a second valve associated with the last mentioned means and for shutting off supply of liquid refrigerant to the first and to the second heat exchanger, respectively, conduit and valve means for conveying evaporated refriger ant selectively from either heat exchanger to the compressor, means responsive to a predetermined maximum temperature of said substance for effecting operation of the compressor and for opening the first valve, and means responsive to a predetermined minimum temperature for effecting operation of the compressor and for opening the second valve, and a control mechanism which is adapted in one condition to render the maximum temperature responsive means operative and. the minimum temperature responsive means inoperative and to effect adjustment of the valve means for, cooling operation of the reversible refrigerating apparatus, and which is adapted in a second position to render the minimum temperature responsive means operative and the maximum temperature responsive means inoperative and to effect adjustment of the valve means for heating operation of the reversible refrigerating apparatus.

20. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger adapted to function as evaporator and condenser, respectively, or vice versa, the first heat exchanger being in heat-exchanging relation with the substance to be heated or cooled, control means adapted to be placed in a first condition for effecting heating operation and in a second condition for effecting cooling operation, and means operative when the control means is in said first condition to provide for fiow of refrigerant from the compressor to the first heat exchanger, in which it is condensed, then to the second heat exchanger, in which it is evaporated, and back to the compressor, and operative when the control means is in said second condition to provide for flow of refrigerant from the compressor to the second heat exchanger, in which it is condensed, then to the first heat exchanger, in which it is evaporated, and back to the compressor.

21. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger, said second heat exchanger being of the dry type and havin a refrigerant passage extending from an upper level to a lower level, means for conveying comveying evaporated refrigerant selectively from the first heat exchanger or from the lower end of the passage in the second heat exchanger to the suction inlet of the compressor.

22. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger adapted to function as evaporator and condenser, respectively, or vice versa, the first heat exchmer being in heat-exchanging relation with the substance to be heated or cooled, control means adapted to be placed in a first condition for effecting heating operation and in a second condition for effecting cooling operation, means responsive to a predeterminedminimum temperature for controlling heating operation of the compressor, and means responsive to a predetermined maximum temperature for controlling cooling operation of the compressor.

23. Reversible refrigerating apparatus for heating and cooling comprising a compressor, a first and a second heat exchanger adapted to function as condenser and evaporator, respectively, and vice versa, the firsteheat exchanger being in heat exchanging relation with the substance to be heated or cooled, and means for selectively conditioning the apparatus for fiow of refrigerant from the compressor to the first heat exchanger in which it is condensed, then to the second heat exchanger, in which it is evaporated, and back to the compressor, to provide heating operation of the apparatus and for controlling said heating operation in response to a predetermined minimum temperature, or conditioning the apparatus for fiow of refrigerant from the compressor to the second heat exchanger, in which it is condensed, then to the first heat exchanger, in which it is evaporated, and back to the compressor, to provide cooling operation of the apparatus and for controlling said cooling operation in response to a predetermined maximum temperature.

24. In reversible refrigerating apparatus for heating and cooling a substance, the combination of a compressor, a motor for driving the compressor, a first and a second heat exchanger adapted to function as condenser and evaporator,

respectively, or vice versa, the first heat exchanger being in heat exchange relation with 'the substance to .be heated or cooled, conduit and valve means for selectively conveying compressed refrigerant from the compressor to the first heat exchanger in which it is condensed, then to the second heat exchanger in which it is evaporated,

and back to the compressor, for heating operation,

or conveying compressed refrigerant from the compressor to the second heat exchanger in which it is condensed, then to the first heat exchanger, in which it is evaporated, and back to the compressor, for cooling operation, electrically energized means for actuating said valve means, electrical circuits for said last-mentioned means and for said motor, and means for controlling said circuits and electrically energized means for selectively actuating said valve means to provide flow of refrigerant for heating operation or actuating said valve means to provide fiow of refrigerant for cooling operation.

25. In reversible refrigerating. apparatus for heating and cooling a substance, the combination of a compressor; a motor for driving the compressor; a first and a second heat exchanger adapted to function as condenser and evaporator, respectively, or vice versa, the first heat exchanger being in heat exchange relation with the substance to be heated or cooled; conduit and valve means for selectively conveying compressed refrigerant from the compressor to the first heat exchanger in which it is condensed, then to the second heat exchanger in which it is evaporated, and back to the compressor, for heating operation, or conveying compressed refrigerant from the compressor to :the second heat exchanger in which it is condensed, then to the first heat exchanger, in which it is evaporated, and back to the compressor, for cooling operation; electrically energized means for actuating said valve means; electrical circuits for said last-mentioned means and for said motor; means for controlling said circuits and electrically energized means for selectively actuating said valve means to provide flow of refrigerant for heating operation or actuating said valve means .to provide fiow of refrigerant for cooling operation; means responsive to a predetermined minimum temperature for controlling operation of the apparatus when the valve means is actuated to provide flow of refrigerant for heating operation; and means responsive to a predetermined maximum temperature for controlling operation of the apparatus when the valve means

Images