US2986898A

US2986898A - Refrigeration system with refrigerant operated pump

Info

Publication number: US2986898A
Application number: US845151A
Authority: US
Inventors: Jr Charles P Wood
Original assignee: Vilter Manufacturing LLC
Current assignee: Copeland Industrial LP
Priority date: 1959-10-08
Filing date: 1959-10-08
Publication date: 1961-06-06
Anticipated expiration: 1978-06-06

Description

June 6, 1961 Q W D, JR 2,986,898

REFRIGERATION SYSTEM WITH REFRIGERANT OPERATED PUMP Filed Oct. 8. 1959 2 Sheets-Sheet l I3 I l2 i 22 h *b /4 I 3; h ,5 I COOL/N6 l T ?NDE;VSER 2/ COIL & J 42 I //7 I'll v 25, I R51. c /8 20 36 v Q 26 RE T 39 33 53 l comp/mm? P cY '"H I 47 J I? W 47 42: 4/ J 39 REL R'EL 33 4 I R2 3 Q's l. l 52 35 T INVENTOR.

I CHARLES 1P. W001: JR

BY M, M a meeu.

OVffor-nzqs June 6, 1961 c. P. wooo, JR 2,936,893

REFRIGERATION SYSTEM WITH REFRIGERANT OPERATED PUMP Filed Oct. 8. 1959 2 Sheets-Sheet 2 SUPPLYVOIATAGE Eel 3 INVENTOR. EHARLEs JP. W001: JR.

O fformzgs Uni e t Page "O 73 2,986,898 REFRIGERATION SYSTEM WITH REFRIGERANT OPERATED PUMP Charles P. Wood, IL, Cincinnati, Ohio, assignor to The Vilter Manufacturing Co., Milwaukee, Wis., a corporation of Wisconsin Filed Oct. 8, 1959, Ser. No. 845,151 Claims. (Cl. 62-174) The present invention relates generally to improvements in the art of refrigeration, and relates more particularly to an improved refrigeration system embodying a pump which is energized by the refrigerant for returning low pressure refrigerant to the high pressure side of the system.

-It has heretofore been proposed to provide a refrigerant system which includes a pump for forcing accumulated liquid refrigerant from an accumulator or the like under relatively high pressure back to a storage tank or the like. However, in such instances wherein a pump was utilized, it was common practice to energize the pump by an outside or separate source of power, thus necessitating costly pump driving mechanism as well as suit able controls therefor.

It has also been proposed to utilize an ejector for forcing liquid under pressure from an accumulator to a trap from which it is adapted to flow by gravity back to the high pressure receiver, and in such a system, it is customary for the ejector to be energized by the refrigerant. However, the use of an ejector does not provide positive operation and presents serious problems with respect to control.

Accordingly, an important object of this invention is to provide an improved refrigerating system wherein novel and improved means are provided for returning low pressure refrigerant to the high pressure side of the system and which obviates the objections and disadvantages attendant prior systems of this general type.

Another object of the invention is to provide an improved refrigerating system embodying a novel pump for returning low pressure refrigerant back to the high pressure side of the system, the pump being energized by the refrigerant and being automatically controlled for positive operation in a novel manner.

Still another object of this invention is to provide an improved refrigerating system embodying a free piston pump energized by the refrigerant in the system and controlled by solenoid valves which are in turn actuated by means carried directly by the piston for pumping liquid from the accumulator to the liquid line of the receiver,

the pump being operable by high pressure gas from the condenser.

A further object of the present invention is to provide an improved refrigeration system which is highly efficient and positive in operation, which is simple and economical in construction, and in which the operating parts are automatically controlled.

These and other objects and advantages of the invention will become apparent from the following detailed description.

A clear conception of the various features of the present improvement and of the mode of constructing and operating a typical refrigeration system embodying the invention may be had by referring to the drawings accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the several views.

FIG. 1 is a more or less diagrammatic view showing a typical refrigeration system embodying the invention;

FIG. 2 is a fragmentary perspective view of the refrigerant transfer portion of the improved system showing the liquid pump connections;

i atented June 6, 1961 FIG. 3 is a Wiring diagram showing a suitable control arrangement; and

FIG. 4 is a longitudinal section through one of the improved free piston pumps and a part of its related actuating mechanism.

While the invention has been shown and described herein as being embodied in a refrigeration system having a particular circuitry and arrangement of parts, it is not desired or intended to thereby unnecessarily restrict or limit the application of the invention; and it is also understood that certain descriptive terminology used herein shall be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawings, and particularly FIGS. 1 and 2 thereof, the refrigeration system shown therein as embodying the invention comprises, in general, a compressor 10 receiving low pressure gaseous refrigerant at its inlet end via the line 11 from a suction trap 12 to which refrigerant is conducted by way of line 13 from the cooling coils 14 (only one of which is shown), the high pressure discharge side of the compressor 10 being connected by line 15 to a water cooled condenser 16' which in turn communicates through line 17 with a high pressure receiver 18 from which liquid refrigerant may be conducted as required back to the cooling coils 14 by way of line 19.

The compressor 10 may be of conventional construction driven in the usual manner by an electric motor or the like, and suitable commercially available controls such as thermostatic expansion valves 2t) may be pro-; vided for the cooling coils. Likewise, the condenser 16 and receiver 18 may be of conventional construction and may either consist of two separate units as illustrated, or they may be combined in a single combination cendenser-receiver unit. As is customary, water is circu lated by way of the line 21 through the heat exchange coils of the condenser 16, and high pressure gaseous refrigerant from the compressor discharge line 15 is condensed to liquid form in the condenser 16 and is stored in the receiver 18 until ready for use in the cooling coils or evaporators 14. Following evaporation of the refrigerant for the desired cooling effect, the refrigerant is returned to the compressor 10 through the suction lines 13, 11 to thereby complete the cycle, the suction trap or accumulator 12 being interposed in the suction line in advance of the compressor to collect any return-- ing liquid refrigerant while permitting the evaporated refrigerant to return to the compressor thus protecting the compressor against possible damage from slugs of liquid refrigerant. To maintain a proper liquid level in the trap or accumulator 12

suitable float switches

22, 23 areprovided which are adapted to start and stop the pump 25 as will hereafter more fully appear.

In accordance with the invention, novel means in the form of an automatically operable free piston pump v25 energized by the high pressure gaseous refrigerant in the system are provided for pumping low pressure liquid refrigerant from the suction trap or accumulator 12 to the receiver 18 under pressure for use in the cooling coilsor evaporators 14, the liquid refrigerant thus bypassing the compressor.

This pump 25comprises, in general, a casing 26 hav ing a relatively large displacement chamber 27 therein and somewhat smaller displacement chambers 28, 29 on opposite sides of the central displacement chamber 27," the chambers 27, 28, 29 housing a free dilferential dis-' placement piston having a large diameter engine piston portion 30 reciprocable in the chamber 27 and oppositely directed small diameter pump piston portions 31, 32'- attached thereto or formed integral therewith and reciprocable within the chambers 28, 29, respectively.

The large displacement chamber 27 housing the engine piston 39 has inletports. 33,, 34 at opposite ends e e t.

communicating with the high side of the condenser 16 through a line 35, the

inlets

33, 34 being under the control of

solenoid valves

36, 37, respectively, to alternately admit high pressure refrigerant gas to opposite sides of the engine piston 30. The large displacement chamber 27 also has outlet or exhaust ports 38, 39 at its opposite ends which communicate by way of line 40 with an upper portion of the suction trap or accumulator 12 above the liquid level therein, the outlet ports 38, 39 likewise being under control of

solenoid valves

41, 42, respectively, to alternately exhaust gas from opposite sides of the piston 30 to the low pressure side of the system as the piston is reciprocated by the high pressure gas.

The small displacement chambers 28, 29 housing the

pump pistons

31, 32 are, in turn, provided with

inlet ports

43, 44, respectively, communicating past one

Way check valves

45, 46 via line 47 with the lower end of the suction trap or accumulator 12 below the liquid level therein. Also, the chambers 28, 29 are provided with outlet ports 48, '49, respectively, communicating past one

way check valves

50, 51 with the high pressure receiver 18 by way of the line 52 which has a check valve 53 therein to prevent back fioW. It is thus apparent that as the differential piston is reciprocated by the admission of high pressure refrigerant gas alternately to opposite sides of the large engine piston 30, the smaller pumping,

pistons

31, 32 draw liquid refrigerant from the suction trap 12 and force the same under pressure to the high pressure receiver 18, the liquid refrigerant thereby by-passing the compressor 10.

The action of the pump 25 is entirely automatic and is controlled by the pump itself. For this purpose, means in the form of a suitable control element or switching member 55 is provided which is carried by or otherwise placed under the action of the dilferential piston, the element 55 being shown in the present instance as being attached directly to the small pump piston 32 and extending through the adjacent end of the casing 26. As the control element 55 is reciprocated by the pump piston, it alternately energizes electrical coils S6, 57 thus likewise alternately energizing the

solenoids

37, 42 and 36, 41, respectively, causing the same to open their respective valves. As is apparent from FIG. 3 which shows a typical wiring diagram, the switches 58, 59 on the electronic panel 60 are energized respectively by the

coils

56, 57, but the

relays

61, 62 are dependent not only upon the action of the switches 58, 59 but also upon the action of the

float switches

22, 23 on the accumulator 12 which act to complete the electrical circuit through the 2-pole magnetic relay 63 when the high level float switch 22 closes and to break the circuit through the relay 63 and thereby stop the pump when the low level float switch 23 closes.

Thus, when the liquid level in the trap or accumulator 12 reaches a predetermined high level, the switch 22 is actuated to complete the control circuit through relay 63 and start operation of the pump 25. As the differential piston reciprocates by admission of high pressure gaseous refrigerant to one or the other sides of the large piston 30, the control element 55 is moved with the piston to contact one or the other of the

coils

56, 57 and thereby cause closing of the corresponding switch 58, 59 to thus energize the corresponding sets of

solenoids

37, 42 and 36, 41 through the

relays

61, 62, respectively. The

inlet ports

34, 33 from thehigh pressure side are thereby alternately opened to the engine piston chamber 27 while the exhaust ports 39, 38 are simultaneously alternately opened, and the differential piston is automatically reciprocated to pump liquid refrigerant from the accumulater 12 to the receiver 18 under pressure by action of the

pumppistons

31, 32.

It should. be understood that it is not desired or intended to limit this invention to the exact details of m sses 4 l .0 modest. operation erein hown. a d s ri e si ce. various modifications within the scope of the appended claims may occur to persons skilled in the art to which the invention pertains.

I claim;

I. AYefrigerating system comprising, a compressor having a suction line 'for returningevaporated refrigerant to the compressor and a high pressure gaseous refrigerant line connected with a condenser, a receiver connected withsaid condenser, an accumulator interposed in the suctionline for collecting liquid refrigerant passing through said suction line to prevent delivery thereof to the compressor, and a reciprocating piston type pump for pumping liquid refrigerant from said accumulator to said receiver under pressure, the piston of said pump being operable by high pressure gas from said condenser.

2. A refrigerating system, as defined in claim 1, in which the pump has a differential area displacement piston, the large diameter portion of which constitutes the piston driving portion operable by the high pressure gas and the small diameter portion of which constitutes the liquid pumping. portion.

3. A refrigerating system comprising, a compressor having a suction line for returning evaporated refrigerant to the compressor and a high pressure gaseous refrigerant line connected with a condenser, a receiver connected with said condenser, an accumulator interposed in the suction line for, collecting liquid refrigerant passing through said suction line to prevent delivery thereof to the compressor, a reciprocating free piston pump for pumping liquid refrigerant from said accumulator to said receiverunder pressure, said pump piston being operable by. high pressure gas from said condenser and being con: trolled by solenoid operated valves, and means responsive to the movement of the pump piston for energizing the solenoids to operate said valves.

4. A refrigerating system, as defined in claim 3, in which the pump has a differential area displacement piston, the larger. diameter portion of which constitutes the piston driving portion operable by the high pressure gas and controllable by the solenoid valves and the small diameter portion of which constitutes the liquid pumping portion.

5. A refrigerating system comprising, a compressor having a suction line for returning evaporated refrigerant to the compressor and a high pressure gaseous refrigerant line connected with a condenser, a receiver connected with said condenser, an accumulator interposed in the suction line for collecting liquid refrigerant passing through said suction line to prevent delivery thereof to the compressor, a reciprocating free piston pump for pumping liquid refrigerant from said accumulator to said receiver under pressure, said pump piston being operable by high pressure gas from said condenser and being controlled by solenoid operated valves, an electrical circuit for said solenoid valves, means responsive to the liquid level in said accumulator for opening and closing said circuit, and means responsive to the movement of the pump piston for alternately energizing the solenoids to operate said valves.

6. A refrigerating system, as defined in claim 5, in which the pump has a diiferential area displacement pis-. ton, the larger diameter portion of which constitutes the piston driving portion operable by the high pressure gas admitted alternately to. opposite sides thereof under control of the solenoid valves and the small diameter portion ofwhich constitutes the liquid pumping portion.

7. A refrigerating system comprising, a compressor having a suction line for returning evaporated refrigerant to the compressor and a high pressure gaseous refrigerant line connected with a condenser, a receiver connected with said condenser, an accumulator interposed in the suction line for collecting liquid refrigerant passing through said suction line to prevent delivery thereof to construction or to the precise components of the, system the compressor, a reciprocating free piston combined engine-pump for pumping liquid refrigerant from said accumulator to said receiver under pressure, said enginepump being operable by high pressure gas from said condenser and being controlled by solenoid operated valves, an electrical circuit for said solenoid valves, means responsive to the liquid level in said accumulator for opening and closing said circuit, and a control element carried by the pump piston and movable therewith for alternately energizing the solenoids through a pair of switches to operate said valves.

8. A refrigerating system, as defined in claim 7, in which the engine-pump has a difierential area displacement piston, the larger diameter portion of which constitutes the piston reciprocating portion operable by the high pressure gas admitted alternately to opposite sides thereof under control of the solenoid valves and the small diameter portion of which constitutes the liquid pumping portion carrying the control element.

9. A refrigerating system comprising, a compressor having a suction line connected to the low pressure side of the system for returning evaporated refrigerant to the compressor and a discharge line connected to the high pressure side of the system for conducting high pressure gaseous refrigerant thereto, and a reciprocating piston type pump for circulating liquid refrigerant within the low pressure side of the system, said pump being connected with the high pressure side of the system and being operable by the high pressure gas therein.

10. A refrigerating system, as defined in claim 9, in which the pump has a driving piston portion and a pump piston portion, the driving portion being connected with and operable by the high pressure gas and the liquid pumping piston portion being connected with the low pressure side of the system for delivering liquid refrigerant thereto.

References Cited in the file of this patent UNITED STATES PATENTS 2,265,558 Ward Dec. 9, 1941 2,570,979 Phillips Oct. 9, 1951 2,590,741 Watkins Mar. 25, 1952 2,724,240 Sloan Nov. 22, 1955 2,836,966 Kocher June 3, 1958 2,871,673 Richards Feb. 3, 1959