US3303665A - Means and techniques useful in refrigeration systems - Google Patents

Description

W. A. RAY

Feb. 14, 1967 MEANS AND TECHNIQUES USEFUL IN REFRIGERATION SYSTEMS Filed July 22, 1965 2 Sheets-Sheet 1 fvvszvroe. WLL/RM H. RAY

W. A. RAY

Feb. 14, 1967 MEANS AND TECHNIQUES USEFUL IN REFRIGERATION SYSTEMS 2 Sheets-Sheet 2 Filed July 22, 1965 United States Patent 3,303,665 MEANS AND TECHNIQUES USEFUL IN REFRIGERATION YSTEMS William Alton Ray, North Hollywood, Calif., assignor to International Telephone and Telegraph Corporation,

New York, N.Y., a corporation of Maryland Filed July 22, 1965, Ser. No. 473,939 6 Claims. (Cl. 6232,4)

The present invention relates to means and techniques useful in refrigeration systems, and particularly of the type in which heat exchange elements may be interchanged to accomplish either a heating effect or a cooling effect.

Briefly, a reversible refrigeration system is disclosed herein in which a four-way transfer valve is operated and positioned in accordance with the condition of a solenoid operated pilot valve. Features of the invention involve the construction of the pilot valve, the construction of the four-way transfer valve and also the manner in which they are interconnected.

One phase of the present invention is addressed to the solution or obviation of problems arising as a result of pressure conditions that may result in difficulties in operating the pilot valve. It has been observed that refrigeration systems may at various times, due to high ambient temperatures or other abnormal conditions, develop high head pressures, and these head pressures make it extremely difficult to build small pilot valves for controlling the main transfer valve in a reversible system, and indeed such excessive pressures may actually prevent operation of the pilot valve as intended. This latter condition is a particularly serious condition as refrigeration systems are hermetically sealed, are evacuated and recharged with refrigeration fluid, all of which is time consuming and expensive. One aspect of the present invention therefore involves a unique construction of a pilot valve and its connections in the system whereby pressures, particularly excessive pressures, are ineffective to stall or to prevent operation of the pilot valve, and this in general is accomplished by pressuring the underside of a three-way pilot valve.

It is therefore a general object of the present invention to provide an improved refrigeration system, and particularly one of the reversible type.

Another object of the present invention is to provide an improved three-way pilot valve useful particularly in refrigeration systems.

Another object of the present invention is to provide a four-way transfer valve which is particularly useful in a refrigeration system.

Another object of the present invention is to provide a reversible refrigeration system involving a four-way transfer valve and a three-way pilot valve with the valves being interconnected with respect to each other and to other elements in the system such that pressure conditions in the system are advantageously used to assure operation of the pilot valve under all conditions, and particularly under excessive pressure conditions which may be developed in the system and with assurance that a main slide valve substantially or entirely covers the main ports so that no more than two ports are open to each other at any one time so as to assure no differential head pressure loss in the system which otherwise might result in non-operation of the main valve.

Another specific object of the present invention is to provide an improved refrigeration system in which should excessive pressures be developed, a three-way pilot valve serves to relieve the same with at all times the pilot valve being operable and in control regardless of the pressure.

Another object of the present invention is to provide a system of this character in which the pilot valve relieves excessive pressures.

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Another object of the present invention is to provide a system of this character in which pressures in the system actually tend to aid the pilot valve in its operation.

Another object of the present invention is to provide a system of this character in which the pilot valve is connected such that while one of the sides of the pilot valve may be relieving pressure, the four-way transfer valve responds to such pressures developed across the pilot valve even though leaking.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 illustrates a reversible refrigeration system embodying features of the present invention.

FIG. 2 is generally a transverse sectional view through a pilot valve embodying features of the present invention, the same being intended to be connected in the system of FIG. 1 and being a solenoid operated valve, but for purposes of simplicity the complete solenoid coil is omitted from FIG. 2.

FIG. 3 is a sectional view taken along the line of 33 of FIG. 2.

FIG. 4 is a sectional view taken generally as indicated by lines 44 in FIG. 3.

FIG. 5 illustrates the movable valve element in an intermediate position.

Referring to FIG. 1, the reversible refrigeration system includes a conventional motor operated compressor 10, a pair of heat exchange elements 11 and 12 illustrated in the form of coils, a four-way transfer valve 14 for selectively connecting the pressure outlet connection 10a of compressor 10 to either the coil ends 11a or 12a while simultaneously connecting the suction side or inlet connection 10b of compressor 10 to the other coil end 11b or 1212. For this purpose, the four-way transfer valve which is actually a flow reversing valve is moved and positioned in accordance with the operation of a three-way solenoid operated pilot valve 15. In conventional manner, the other coil ends 11b and 12b are interconnected by expansion valves 11c, 12c and check valves 11d and 12d, and each of the expansion valves 11c and 12c are operated in accordance with thermal conditions at the coil ends 11a and 12a, respectively. For this latter purpose, conventional temperature responsive bulbs 11c, 122, in the form of so-called capillary bulbs, are in heat exchange relationship to the refrigerant leaving the coil ends 11a and 12a, respectively, for operating such expansion valves 11c and in conventional manner.

In the position of the four-way valve 14 shown in FIG. 1, the flow path of the refrigerant is as follows: from the pressure outlet 10a to the valve inlet opening 14a, through the valve connect-ion 14b, to the coil end 1111, through the coil 11 which at this time serves as a condenser element, through the check valve 11d, through the expansion valve 120 which is controlled by the temperature responsive element 12c, through the coil 12, through the valve connection 14c to the valve connection 146, and to the compressor inlet connection ltlb. It is noted that the compressor outlet and inlet connections 10a, 10b are connected directly to the valve connections 14a and 142, respectively, at all times and that the movable valve element 14 serves to selectively communicate, in one position of valve element 14], the connections 14a and 14b and the connections 14c and 146, and in the other position of valve element 14 the connection 14a is placed in communication with connection and 14e is placed in communication with connection 1417 so that in this other position of valve element 14 the coil 12 functions as a condenser element, and the other element 11 functions as an evaporator element. In the first condition described above, the coil 11 functions as a condenser and the coil 12 functions as an evaporator element. In the second condition where the coil 11 functions as an evaporator element, the refrigerant flow is through the check valve 12d and through the expansion valve 11c which is controlled by the thermal responsive element 111;.

The valve 14 has a generally cylindrical stationary valve body 14g having apertured disc shaped end members 14h, 14 for applying suitable pressures to a floating movable piston assembly 14k formed with piston elements 14l, 14m on opposite ends thereof, the assembly 14k being guided in its movement by a stationary pin 1411 on the valve body 14g engaging an elongated slotted portion in a rib portion 14p that interconnects the piston portions 14l, 14m. These piston portions 14l, 14m, as shown, have inwardly extending rod portions each of which are recessed to receive a corresponding coil compression spring 141', 14s acting against a dished valve element 14! to at all times urge it towards the three valve ports in body 14g and at the ends of conduits or connections 14b, 14c, 14c, respectively. For this purpose, the valve element 14t which has a dished portion 14u that forms a conduit for intercommunicating the suction connection or line 14a to either connections or lines 140 or 14b depending upon the position of the assembly 14k is guided for slidable movement on the piston rod portions so that such valve element 141 is spring urged into conformity with the stationary valve ports for providing a seal between valve ports.

In FIGS. 1 and 5, the valve element 141 has sealing surfaces or lands 14v, 14w which are preferably substantially equal to the area of their corresponding ports 14x and 14y, and are such that the center port 14z is never in communication with both ports 14x and My with, for example, the port dimension B being substantially equal to the dimension A. Also, as shown in FIG. 5, when the assembly 14k is in a position to establish communication between either port 14x or 14y, the other port 14x, 14y is in communication with the pressure inlet 14a. When the left-hand edge of land 14v is in alignment with the edge of port 14x as shown in FIG. 5, the valve 14x, 14v is open slightly to place port 14x in communication with suction outlet 14z, and at this time the left-hand edge of land 14w is displaced to the left with respect to the inner edge of port 14y; and also the valve 14w, 14y is open to establish communication between pressure line 14a and line 14b. For these purposes, under the conditions mentioned above, the distance between the righthand edge of land 14w and the outer edge of port 14y may be, for example, 0.187 inch to provide what may be termed a negative overlap.

The pilot valve 15 is shown in more or less diagrammatic form in FIG. 1, and an actual construction may be as shown in FIGS. 2-4. For purposes of comparison like elements have identical reference numerals.

The pilot valve 15 is operated by a solenoid having an energizing coil surrounding a magnetizable plunger 22 which is slidable in a hermeticallysealed casing 24. The casing 24, as shown in FIG. 2, may include a brass sleeve member 24a about which the winding 20 is disposed and which is closed by a plug or cap 26.

The casing 24 is provided with an intermediate wall portion 28 which separates generally the casing into an upper chamber 30 and a lower chamber 32, and L- shaped fluid passages 34 and 36 are in such wall portion 28 with passages 34 and 36 terminating in valve seats 38 and 40, respectively, these valve seats 38 and 40 being in communication via corresponding fluid lines 42 and 44 with ends of the four-way valve housing 14g. As seen in FIG. 4, the chambers 30 and 32 intercommunicate through a bore 46 which is in communication with one end of a fluid line 48, the other end of line 48 communicating with the compressor suction line 142. This bore 46 shown in FIG. 2 is illustrated diagrammatically in FIG. 1 as an interconnecting fluid line 46 for simplicity and ease of comparison.

The valve port 38 and the captivated ball 50 in the floatingly mounted ball carrier assembly 52 defines one valve, and likewise the other valve port 40 and captivated ball 54 in the other floatingly mounted ball carrier assembly 56 defines a second valve. These ball carrier assemblies 52, 56 are of identical construction and involve generally a disc shaped element having means loosely mounting a ball thereon. The lower assembly is contacted and urged upwardly by a coil compression spring 60 having its lower end seated on plug 62. The other or upper ball carrier assembly 52 is contacted and downwardly by the lower end of plunger 22, the plunger being urged downwardly by coil compression spring 66 having its upper end seated on plug 26 and its lower end extending into a fluid channel 63 and engaging the plunger shouldered portion 70. For purposes of illustration in FIG. 1, the seat 38 cooperates with the lower end of plunger 22 to define the previously mentioned valve and similarly the other valve seat 40 cooperates with a spring seat 56a for spring 60 in defining the other previously mentioned valve. As i1 lustrated in FIGS. 1 and 3, a pair of pins 72 and 74 are floatingly mounted in the wall portion 28 to extend between the movable valve elements which in FIG. 2 are the ball carrier assemblies 52 and 56 and in FIG. 1 the plunger 22 and spring seat 56a.

The spring 66 is stronger than the spring 60 so that in the deenergized condition of solenoid winding 20 shown in FIG. 2, the port 38 is closed and the port 40 is open; and when such winding 20 is energized, the port 38 is open and port 40 is closed corresponding to the condition shown in FIG. 1. Energization of winding 20 may thus correspond either to a cooling condition or a heating con dition depending upon where the heat exchange coils 11 and 12 are located with respect to the environment under consideration.

In the energized condition of solenoid 20 as in FIG. 1, the movable valve assembly 14k is positioned to the left being maintained therein due to a pressure differential resulting from the fact that at this time the line 42 is connected via port'38, conduit 46 and line 48 to the compressor suction or return line 142, the other port 40 being closed. To move the valve assembly 14k to the right to its other extreme position, the winding 20 is deenergized to achieve the condition shown in FIG. 2 where now the compressor return or suction line 14c is communicated to the bore in the housing end 14 via line 44, port 40, conduit 46 and line 48, to produce the desired movement as a result of the pressure on the left'hand side of piston 14m being smaller than the pressure on its right hand side. Consequently, flow of refrigerant is reversed through the coils 11 and 12. During the above mentioned movement, there may be sufficient leakage past piston into line 42 to destroy any otherwise adverse cavitation resulting from the piston 14l moving away from housing end 14h; and with such assumed leakage should the pressure in line 42 rise above a predetermined amount, it may be relieved by its causing the port 38 to open in which case such pressure overcomes the force of spring 66.

Subsequently, when it is desired to return the valve assembly 14k to its position shown in FIG. 1, the winding 20 is energized in which case valve port 38 is open and port 40 is closed, and the action is as indicated above with at this time movement being accomplished as a result of a difference in pressure on the outer and inner surface of piston 14l with the port in this instance being opened slightly to relieve any excessive pressure conditions in line 44 resulting from any leakage past the piston 14m. When the port 40 is thus opened, the pressure overcomes the force of spring 60.

It will also be seen that excessive pressures, when and as they are developed in the system, act on elements of the pilot valve such that they do not tend to stall or prevent movement of the solenoid plunge'r. Thus, under the static condition shown in FIG. 1, the chambers 30 and 32 intercommunicated by passageway 46 (FIG. 4) are at the pressure of the suction line 14e (FIG. 1), and pressure in line 42 aids the winding 20 when energized to move the plunger 22 to its upper attracted position in FIG. 1. Also, in the static condition shown in FIG. 1, excessive pressure in line 44 applied to spring 60 overcomes the action of spring 60 on plunger 22 to render spring 66 more effective to move the plunger 22 down- War'dly When winding 20 is deenergized. This arrangernent results in permissive use of a smaller, more reliable pilot valve.

It should be noted in particular that the main slide valve element 14 substantially or entirely covers the main ports 14b, 14c, 14e such that no more than two of such ports are open to each other at any one time. If this is not done, the differential head pressure in the system required to operate the valve element 14] may be lost, hence resulting in stalling the movement of the main valve element 14 While the particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. In a reversible refrigeration system of the character described the combination comprising: a compressor having a pressure outlet and an exhaust inlet; a first coil; 21 second coil; a four-way transfer valve including a casing and a valve element slidably mounted in said casing; an electromagnetically operated pilot valve; said casing having a pressure inlet in communication with the pressure outlet of said compressor; said casing having an exhaust outlet in communication with said compressor exhaust inlet; means intercommunicating one end of said first coil with one end of said second coil; said casing having a first valve port in communication with the other end of said first coil; said casing having a second port in communication with the other end of said second coil; said valve element being effective in a first position thereof to intercommunicate said casing pressure inlet with said first port and simultaneously intercommunicate said casing exhaust outlet with said second port; said valve element being effective in a second position thereof to intercommunicate said casing pressure inlet with said second port and to simultaneously intercommunicate said first port with said casing pressure exhaust outlet; said valve element having a first piston and a second piston respectively on opposite ends thereof which define with said casing a corresponding first casing chamber and a second casing chamber; said pilot valve including a housing defining two chambers; means intercommunicating said casing exhaust outlet with each of the two last mentioned chambers; said last two mentioned pilot valve chambers being separated by a wall portion; two fluid channels extending through said wall portion and terminating respectively at a corresponding valve seat, one of said fluid channels being in communication with said first casing chamber and the other of said fluid channels being in communication with said second casing chamber; a valve element in one of said pilot valve chambers; resilient means normally urging the last mentioned valve element into engagement with one of said pilot valve ports; a solenoid plunger movably mounted in the other of said Pi19t a e ch mbe s and in u g a ve means 6 cooperating with the other of said pilot valve ports; means normally urging said plunger to normally close the last mentioned port; and means interconnecting said plunger and the valve element in said one pilot valve chamber.

2. In an arrangement as set forth in claim 1 in which the last mentioned means is a one-way connection between the plunger and the valve element in said one pilot valve chamber.

3. In an arrangement as set forth in claim 1 in which the first mentioned valve element includes a valve member slidably mounted on said piston portions with spring means acting between said piston portions and said member to urge said valve member toward said first and second casing ports.

4. In a reversible refrigeration system of the character described, wherein a four-way transfer valve is effective to reverse the direction of flow of refrigerant through a first and a second coil in accordance with refrigerant pressure acting on a slide valve element movable in a casing which defines with said slidable valve element a first chamber and a second chamber, and wherein said casing has a refrigerant pressure inlet, an exhaust outlet, and a pair of ports cooperating with said valve element, and wherein said pair of ports are respectively in communication with a corresponding one end of said first and second coils with means being provided to intercommunicate the other ends of said coils, and wherein said valve element, in one position thereof, is effective to selectively communicate said pressure inlet to said one end of said first coil and to simultaneously intercommunicate said exhaust outlet with said one end of said second coil, and wherein, in a second position of said valve element, said valve element is effective to selectively communicate said pressure inlet with said one end of said second coil and to simultaneously intercommunicate said exhaust outlet with said one end of said first coil, the improvement which resides in providing first valve means for communicating said first chamber to said exhaust outlet, second valve means for communicating said second chamber with said exhaust outlet, electromagnetically operated means including a plunger movable in a closed chamber in a housing, said closed chamber being in communication at all times with said exhaust outlet, said plunger in its energized condition being effective to open said first valve and close said second valve and being effective in its deenergized condition to close said first valve and open said second valve, the said first valve and second valve means including parts in different closed spaces, said first valve having a movable element, and a one-way connection between said plunger and said movable valve element.

5. A reversible refrigeration system as set forth in claim 4, including first means urging said plunger to normally close said second valve and to normally open said first valve, and second means, weaker than said first means, tending to move said movable valve element to its valve closing position.

6. A system as set forth in claim 1 in which said valve element is movable to substantially cover said ports such that at no time are said ports open to each other.

References Cited by the Examiner UNITED STATES PATENTS 2,976,701 3/1961 Greenawalt 62324 2,991,631 7/1961 Ray -a 62-324 3,056,574 10/1962 Greenawalt 62-324 WILLIAM J. WYE, Primary Examiner.

Claims (1)

1. IN A REVERSIBLE REFRIGERATION SYSTEM OF THE CHARACTER DESCRIBED THE COMBINATION COMPRISING: A COMPRESSOR HAVING A PRESSURE OUTLET AND AN EXHAUST INLET; A FIRST COIL; A SECOND COIL; A FOUR-WAY TRANSFER VALVE INCLUDING A CASING AND A VALVE ELEMENT SLIDABLY MOUNTED IN SAID CASING; AN ELECTROMAGNETICALLY OPERATED PILOT VALVE; SAID CASING HAVING A PRESSURE INLET IN COMMUNICATION WITH THE PRESSURE OUTLET OF SAID COMPRESSOR; SAID CASING HAVING AN EXHAUST OUTLET IN COMMUNICATION WITH SAID COMPRESSOR EXHAUST INLET; MEANS INTERCOMMUNICATING ONE END OF SAID FIRST COIL WITH ONE END OF SAID SECOND COIL; SAID CASING HAVING A FIRST VALVE PORT IN COMMUNICATION WITH THE OTHER END OF SAID FIRST COIL; SAID CASING HAVING A SECOND PORT IN COMMUNICATION WITH THE OTHER END OF SAID SECOND COIL; SAID VALVE ELEMENT BEING EFFECTIVE IN A FIRST POSITION THEREOF TO INTERCOMMUNICATE SAID CASING PRESSURE INLET WITH SAID FIRST PORT AND SIMULTANEOUSLY INTERCOMMUNICATE SAID CASING EXHAUST OUTLET WITH SAID SECOND PORT: SAID VALVE ELEMENT BEING EFFECTIVE IN A SECOND POSITION THEREOF TO INTERCOMMUNICATE SAID CASING PRESSURE INLET WITH SAID SECOND PORT AND TO SIMULTANEOUSLY INTERCOMMUNICATE SAID FIRST PORT WITH SAID CASING PRESSURE EXHAUST OUTLET; SAID VALVE ELEMENT HAVING A FIRST PISTON AND A SECOND PISTON RESPECTIVELY ON OPPOSITE ENDS THEREOF WHICH DEFINE WITH SAID CASING A CORRESPONDING FIRST CASING CHAMBER AND A SECOND CASING CHAMBER; SAID PILOT VALVE INCLUDING A HOUSING DEFINING TWO CHAMBERS; MEANS INTERCOMMUNICATING SAID CASING EXHAUST OUTLET WITH EACH OF THE TWO LAST MENTIONED CHAMBERS; SAID LAST TWO MENTIONED PILOT VALVE CHAMBERS BEING SEPARATED BY A WALL PORTION; TWO FLUID CHANNELS EXTENDING THROUGH SAID WALL PORTIO AND TERMINATING RESPECTIVELY AT A CORRESPONDING VALVE SEAT, ONE OF SAID FLUID CHANNELS BEING IN COMMUNICATION WITH SAID FIRST CASING CHAMBER AND THE OTHER OF SAID FLUID CHANNELS BEING IN COMMUNICATION WITH SAID SECOND CASING CHAMBER; A VALVE ELEMENT IN ONE OF SAID PILOT VALVE CHAMBERS; RESILIENT MEANS NORMALLY URGING THE LAST MENTIONED VALVE ELEMENT INTO ENGAGEMENT WITH ONE OF SAID PILOT VALVE PORTS; A SOLENOID PLUNGER MOVABLY MOUNTED IN THE OTHER OF SAID PILOT VALVE CHAMBERS AND INCLUDING VALVE MEANS COOPERATING WITH THE OTHER OF SAID PILOT VALVE PORTS; MEANS NORMALLY URGING SAID PLUNGER TO NORMALLY CLOSE THE LAST MENTIONED PORT; AND MEANS INTERCONNECTING SAID PLUNGER AND THE VALVE ELEMENT IN SAID ONE PILOT VALVE CHAMBER.

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