US2801528A

US2801528A - Compressor in air conditioning system

Info

Publication number: US2801528A
Application number: US333143A
Authority: US
Inventors: Parcaro Michael
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-01-26
Filing date: 1953-01-26
Publication date: 1957-08-06
Anticipated expiration: 1974-08-06

Description

* M. PARCARO CGMPRESSOR IN AIR CONDITIONING SYSTEM Filed Jan. 26, 195;

Aug. 6, 1957 2,801,528

4 Sheeis-Sheet 1 INVENTOR Micfiael .Parcaro Aug. 6, 1957 M PARCARO COMPRESSOR IN AIR CONDITIONING SYSTEM Filed Jan. 26, 1953 4 Sheets-Sheet 2 INVENTQR Michael Parcaro Aug. 6, 1957 PARCARO 2,801,528

' COMPRESSOR IN AIR counrr onmc syswpu Filed Jan. 26, 1953 4 Sheets-Sheet 3 INVENTOR Michael larcam BY M. PARcARo ,528 COMPRESSOR IN AIR CONDITIONING SYSTEM Filed Jan. 26, 1953 Aug. 6, 1957 4 Sheets-Sheet 4 1 5 102 I16 i I06 INVENTOR Michael Pal-Caro United States Patent flice 2,801 ,528 Patented Aug. 6, 1957 COMPRESSOR IN AIR CONDITIONING SYSTEM Michael Parcaro, Arlington, N. J. i 1' Application January 26, 1953, Serial No. 333,143

14 Claims. (Cl. 62-115) This invention relates to refrigeration and air conditioning; and more in particular to a new system and new compressor or pump and flow-reversing valve arrangements, whereby the direction of fluid flow is reversed automatically without auxiliary valves or the like.

An object of this invention is to provide an improved refrigeration system whereby the refrigerant flow may be reversed. A further object is to provide a system wherein one element of the system is cooled during one mode of operation, and wherein that element is heated by the simple action of a flow-reversing mechanism which forms an integral part of the compressor. A further object is to provide an improved system of the above character wherein successive refrigeration and defrosting operations may be carried on in an eflicient and dependable manner. Another object is to provide a simplified and highly efficient air-cooling and heat-pump system. Another object is to provide a refrigeration system wherein a compressorunloading operation can be carried on in a dependable and efiicient manner. A still further object is to provide an improved valve and compressor arrangement by which the above may be accomplished. These and other objects will be in part obvious and in part pointed out below.

In the drawings:

Figure 1 is a somewhat schematic representation of a refrigeration system which is an illustrative embodiment of the invention;

Figure2 is a vertical section on the line 22 of Figure 1 with parts broken away;

Figures 3, 4, 6 and 7 are sectional views on the respective lines 33, 44, 6-6 and 77 of Figure 2;

Figure is a somewhat schematic sectional view of the valve mechanism;

Figure 8 is a sectional view on the line 8-8 of Figure 7;

Fig. 9 is a diagrammatic view of the compressor and valve assembly arranged to unload volatile fluids from a tank car to a storage tank.

Referring now to Figure 1 of the drawings, the refrigeration system for a low temperature storage space is illustrated somewhat schematically. The air in the space is cooled by an evaporator 10 which has air cooling surfaces below freezing upon which ice or frost accumulates and must be removed by defrosting.

This refrigeration system comprises: a compressor and valve assembly 2, driven by an electric motor 4; a condenser-evaporator unit 6 enclosed in a water tank 7; a receiver 8; and, an evaporator-condenser unit 10. The compressor and valve assembly is connected to the evaporator-condenser unit 10 through a pipe 14. Unit 6 is connected to the receiver through a liquid line 16, which has a one-way valve 18 therein, through which liquid refrigerant may flow to the receiver, but there can be no flow in the reverse direction. Unit 6 is also connected to the receiver through a liquid line 20, having an expansion valve 22 therein. A similar liquid line 24 connects the receiver to the top of the evaporator-condenser unit 10, and has an expansion valve 26 therein. The top of unit 10 is also connected to the receiver through a line 28, having a one-way valve 30 therein, through which liquid refrigerant may flow from unit 10 to the receiver, but there can be no flow in the reverse direction.

Line 28 also has a pan-heating coil 32 connected therein so that hot liquid flowing from the evaporator flows through this coil and heats the pan and condensate outlet. Assuming that motor 4 is operating the compressor, (and the compressed refrigerant flows from the compressor to condenser-evaporator unit 6, this unit. acts as a con denser with the refrigerant being cooled by water in tank 7. The condensed refrigerant flows from the bottom of unit 6 through the one-way valve 18 and line 16 into the receiver. The liquid refrigerant then flows from the receiver through line 24, and expansion valve 26 to the evaporator-condenser unit 10. Unit 10 acts as an evaporator and cools air which is blown over it by a fan 34 so as to cool the refrigerated space. Controls are provided to maintain the desired operation.

However, as indicated above, evaporator 10 is below freezing and frost accumulates, thus making it desirable to defrost the unit. During the defrosting operation, the compressed refrigerant flows through pipe 14 to unit 10, which acts as a condenser so as to heat the evaporator surfaces. The refrigerant is condensed and flows through valve 30, coil 32 and pipe 28 to the receiver. .The liquid refrigerant flows through the receiver through line 20 and expansion valve 22 to the bottom of unit 6, which acts as an evaporator to extract heat from the water in tank 7. The gaseous refrigerant returns to the compressor through pipe 12. Thus, the surfaces of unit 10 are heated so as to melt the ice free, with the water flowing through tank 7 being the heat source. In flowing downwardly the condensed hot refrigerant passes through the coil 32 so as to heat a pan beneath the evaporator into which the melted frost drips. This insures that the melted frost will not refreeze, but will flow to a waste discharge, or trap.

When the system herein disclosed is used as outlined above, the reversal of flow is effected automaticallyby a reversing valve assembly 36, which is part of the head of the compressor. This assembly includes the reversing valve portion 38 and the operating portion 40. The assembly 36 is operated by supplying gas. under pressure to unit 40 through a line 42 from a control unit 43. Assembly 36 is so constructed as to operate thesystem to cool the unit 10 when no pressure is applied through tube 42, and the operation is reversed when pressure is applied. At the left, there is a high-pressure gauge 44, which is connected through a line 46 to the outlet side of the compressor, and this line extends to the control unit 43. At the right, there is suction gauge 48, which is connected to the suction side of the compressor through a line 50, which also extends to unit 43. Unit 43 is connected to a controller 52 which initiates and controls the defrosting operations.

Figures 2 to 8 show the details of construction of the compressor and the reversing valve assembly 36. Referring to Figure 2, the top of the compressor cylinder block 54 is shown, there being two

cylinders

56 and 58 within which are two

pistons

60 and 62. Closing the tops of these cylinders is a valve plate 64, which carries for each cylinder a pair of inlet valves 66 and a pair of outlet valves 68. The valve plate 64 is covered by .a flow-reversing block 70 (see also Figure 3 and the somewhat schematic showing of Figure 5), which has a top wall 72, with a peripheral downwardly extending wall portion 74 (Figure 2) and a longitudinal dividing wall 76 (Figure 3). The peripheral wall and this dividing wall form two header chambers, there being an inlet header chamber 78 into which valves 66 (Figure 2) open,

and an outlet header chamber 80 into which valves .68

open. Thus, the inlet and

outlet valves

66 and 68 are positioned so that the inlet ports draw the gas from the inlet chamber 78 and the outlet ports discharge the compressed gas into the outlet chamber 80.

The reversing valve assembly is mounted in a cylindrical shell 82 integral with the top wall 72. There are two valve stems (see Figure 8) 84 and 86 slidably mounted in sleeves in a fixed plate 88 which is clamped at its periphery by stud bolts 90 and the flange of a cylinder shell 92. Slidable in the cylinder shell 92 is a piston 94 to which the upper ends of

valve stems

84 and 86 are rigidly attached. Valve stem 84 carries a pair of

valve elements

96 and 98 which are moved together by the stem between the lower position shown with element 98 seated and an upper position wherein element 96 is seated. When element 98 is seated, the central chamber 100 is open to an upper chamber 102; and, when element 96 is seated, chamber 100 is open to a lower chamber 104. Valve stem 86 carries a similar pair of

valve elements

106 and 108 which are reversely disposed so that element 106 is seated when the stem is down and element 108 is seated when the stem is up. There is a central chamber 119 which is open to chamber 104 when element 106 is seated, and is open to chamber 102 when element 193 is seated. As represented in Figure 5, chambers 110 and 104) are connected respectively to the outlet chamber 89 and the inlet chamber 78 by passageways 114 and 112 (see also Figures 6 and 7).

Chambers

102 and 104 are connected respectively through

passageways

116 and 118 to the gas inlet and outlet ports or connections 120 and 122 (see Figure 1) upon the sides of the compressor cylinder to which

pipes

14 and 12 are connected.

Piston 94 is adapted to slide between the positions of Figures and 8 so as to move the valve elements between their two positions thus to reverse the flow of refrigerant in the system. In the embodiment of Figure 1, the normal flow is as first described, and the flow is reversed to defrost the evaporator. During the defrosting operation the frost starts to melt immediately and the operation is completed in minimum time. The reversal at the end of the defrosting operation is followed immediately by cooling of unit 10. Fan 34 is stopped during the defrosting operation.

This same general refrigeration system, particularly with this combination compressor and reversing valve assembly is ideally suited for heat pump systems where cooling is produced in the summer and heating is produced in the winter. With such operation, the control is automatic, and changes between cooling and heating are made in accordance with the demands of the conditioned space. This assembly may also be used for 11nloading one or more cylinders of a multi-cylinder compressor. In such cases the reversal of the flow, i. e., intake and discharge, of one cylinder or one pair of cylinders reduces the suction and head pressures because there is a short-circuit of the refrigerant. Thus, for example, with one-half of the cylinders reversed, the entire compressor is unloaded.

The compressor and reversing valve assembly is also ideally suited for multi-staging a multi-cylinder compressor system, or a system having two or more compressors may be multi-staged. For example, a refrigeration system having two or more cylinders or pairs of cylinders may be operated normally as a single stage system with all of the cylinders in parallel; and then, one or more of the cylinders may have their flow reversed automatically and the flow circuit changed to two-stage operation. In this way, it is possible to provide an extremely low temperature, for example, to perform pre-cooling or freezing operations with the multi-stage arrangement, while the single-stage operation is used to handle the normal load. This arrangement for single and multistage operation may also be used in a heat-pump system to increase the heat output range and the versatility. Thus, with a heat-pump system, the single-stage operation will carry the heating load when the temperature of the A heat source medium is relatively high; when the temperature of this medium drops, the heat-pump system changes over automatically to its multi-stage operation.

The compressor and reversing valve assembly herein disclosed is also ideally suited for incorporation into a system for unloading volatile fluids such as propane. As illustrated in Fig. 9, such a system is provided for unloading propane from railway tank cars 130, and for delivering it to stationary storage tanks 132. During the initial unloading operation, the liquid propane flows through a liquid line 134 directly from the bottom of the tank car to the stationary storage tank. The compressor and valve assembly 2 is then operated to withdraw propane gas from the top of the storage tank 132 and deliver it to the top of the railway car tank 130, and this permits rapid flow of the liquid so that all of the liquid flows from the tank car. The diiference in pressures in the tops of the two tanks is sufficient to cause the liquid to flow even though the level in the storage tank is above that in the car tank.

When the liquid has all passed from the car tank 130, the propane gas starts to flow through the liquid line, and a relay 136 in this line is responsive to the change in the medium which is flowing. This relay 136 automatically closes a valve 138 in this line so as to stop the flow therethrough. This relay also reverses the valves of the compressor and the reversing valve assembly so as to withdraw the propane gas from the tank car and pump it into the storage tank. A piping and valving arrangement is provided whereby this propane gas under pressure is delivered to the body of liquid in the tank and bubbles upwardly therethrough so that it is condensed. When the suction pressure, which is the pressure in the car tank, is reduced to a predetermined value, the operation is discontinued automatically.

This same arrangement may be provided for transferring liquids or fluids between various tanks, either stationary or mobile. With such operation the compressor may be referred to as a pump because its primary purpose may be considered a pumping operation with there being a relatively small difference between the intake and discharge pressures. The assembly is therefore referred to as a pump and reversing valve assembly.

In each of the embodiments herein disclosed, it is apparent that the unitary compressor or pump and reversing valve assembly produces an entirely new mode of operation. The heat exchange relationship between the inlet and outlet streams insures proper and eflicient operation at all times. The results are uniform, and the reversing operations are carried on without any objectionable efiects.

I claim:

1. In a refrigeration system, an evaporator which tends to accumulate frost during a cooling operation, a condenser, and a unitary compressor and reversing valve assembly which normally delivers compressed refrigerant to said condenser and withdraws refrigerant from said evaporator, said assembly being adapted to reverse the refrigerant flow so as to deliver compressed refrigerant to said evaporator to melt the frost free, and said unitary compressor and reversing valve assembly comprising a compressor head having passages for the flow of refrigerant to and from the compressor and reversing valve means mounted in the head and cooperating with said passages therein.

2. A system as described in claim 1 wherein said cornpressor draws refrigerant in through an inlet chamber in the head and delivers compressed refrigerant out through a discharge chamber in the head, a first pipe means connecting said assembly to said evaporator, a second pipe means connecting said assembly to said condenser, and in which said reversing valve means and passages are in heat exchange relationship with the compressor and connect said chambers respectively to said first and second pipe means and to reverse said connections.

3. The system as described in claim 2, which includes a reversing valve comprising, a pair of parallel valve stems, two pairs of valve elements mounted with one pair on each of said stems, a valve body having two central valve chambers associated respectively with said stems and each having two discharge ports which are closed alternatively by said elements.

4. In a refrigeration system, a compressor unit having a head, passages in the compressor head terminating in inlet and outlet ports, and a reversing valve assembly mounted in the head of said compressor and cooperating with said passages in said head for directing fluid through the passages in heat conducting relationship with said compressor.

5. A system as described in claim 4 wherein said reversing valve assembly includes an inlet chamber and an outlet chamber, and two double valve elements connected to control the flow.

6. A system as described in claim 5 which includes, an evaporator-condenser, a condenser-evaporator, and expansion control means through which liquid refrigerant is supplied alternatively.

7. In a fluid pumping system of the character described, the combination of, a pair of containers for a volatile fluid, and a unitary pump and reversing valve assembly connected between said containers and including a pump having a head with fluid passages therein and a reversing valve in the head cooperating with said passages whereby the fluid may be pumped from one of said containers to the other and then said valve may be operated to reverse the flow.

8. A system as described in claim 7 wherein said pump is of the reciprocating piston type which includes a cylinder block having fluid inlet and outlet passageways, and the head is a cylinder head assembly within which said reversing valve is enclosed.

9. A system as described in claim 8 which is a refrigeration system including an evaporator wherein said reversing operation heats said evaporator.

10. A system as described in claim 8 wherein one of said containers is a tank car, and said unitary pump and reversing valve assembly is arranged to supply gas from the other containers to the top of the tank car, and wherein said reversing operation withdraws and compresses gas from the top of said tank car.

11. In a fluid pumping system of the character described, the combination of, a pair of containers for a volatile fluid, and a unitary pump and reversing valve assembly connected between said containers and including a pump having a chamber in which fluid is pumped, a head provided with intake and outlet passages to and from the pump chamber and a reversing valve in the head cooperating with said intake and outlet passageways, said assembly having a block in which said pump is eni 8 closed, the intake and outlet passageways also extending through said block whereby heat energy present in this block is readily transferred to the fluid flowing through said passageways thus insuring continued operation of the pump when the valve is reversed.

12. In a fluid pumping system of the character described, the' combination of, a pair of containers for a volatile fluid, and a unitary pump and reversing valve assembly connected between said containers and including a pump having a head provided with intake and outlet passages and a reversing valve with chambers in the head connected to the intake and outlet passages, said pump including a block with a cylinder therein, said intake and outlet passageways being formed through a portion of said block whereby any fluid flowing in said passageways to said valve chambers will be heated before it reaches the valve and pump thereby safeguarding operation.

13. In a refrigeration system wherein the direction of flow of the refrigerant can be reversed by a reversing valve, a refrigerant pump having a pumping chamber and a head enclosing a portion of the chamber, said head having passageways leading to and from the chamber, and reversing valve means in the head and cooperating with said passageways to and from the chamber, and said passageways having substantial portions positioned in heat exchange relation with said chamber whereby any re- 'frigerant liquid flowing in said passageways to and from said valves is converted by the heat energy present in the body of said pump to a gaseous phase before it can reach said valve and pump.

14. The system as in claim 13 wherein said pump has a block forming said chamber and through which substantial portions of said passageways to and from said chamber are formed.

References Cited in the file of this patent UNITED STATES PATENTS 721,662 Bower Mar. 3, 1903 1,219,373 Byens Mar. 13, 1917 1,247,884 Scovel, Jr. Nov. 27, 1917 1,904,531 Raymond Apr. 18, 1933 1,982,264 Naab NOV. 27, 1934 2,004,074 Kiley June 18, 1935 2,162,245 Comstock June 13, 1939 2,342,174 Wolfert Feb. 22, 1944 2,394,237 Froehlich Feb. 5, 1946 2,634,047 Shurson Apr. 7, 1953 2,638,123 Vargo May 12, 1953 2,682,154 Wilkinson June 29, 1954 2,715,318 Millrnan Aug. 16, 1955 FOREIGN PATENTS 596,328 Great Britain Jan. 1, 1948