US2051110A - Refrigeration apparatus - Google Patents

Description

1936- y L. R. SMIT'H 2,051,110

REFRIGERATION APPARATUS Filed Aug. 5, 1933 EVA-Perelman.

Patented Aug. 18, 1936 REFRIGERATIQN A?PARATUS Lewis B. Smith, Pittsburgh, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 3, 1933, Serial No. 683,534

1 Claim.

My invention relates to refrigerant condensing and cooling apparatus for refrigeration systems, more particularly to air-cooled condensing and cooling apparatus, and it has for an object 5 to provide apparatus of the character set forth which will effect increased efliciency of the refrigerating cycle.

A further object is to increase the emciency of the refrigeration system for a given area of refrigerant cooling surface.

A further object is to reduce the compression displacement and the power required for a refrigeration system of given capacity.

A more specificobject is to reduce the compression displacement and the power required for a refrigeration system of given capacity and given refrigerant cooling surface.

A more particular object is to provide aircooled condensing and cooling apparatus in which a substantially constant quantity of condensed refrigerant is cooled substantially to the temperature of the cooling air, independently of the liquid level in the liquid receiver.

A further object is to provide condensing and cooling apparatus having a cooling coil, or other form of heat exchanger, to which only condensed refrigerant is admitted.

In refrigeration systems using a refrigerant whose latent heat is low, and whose specific heat 30 of liquid is high, such as dichlorodifluoromethane, in order to obtain maximum cooling for each pound of refrigerant evaporated, it is advisable to cool the liquid considerably below the temperature of condensation in an air-cooled con- 35 denser.

For example, using cooling air at 95 F., and dichlorodifiuoromethane as the refrigerant, the condensing temperature may be as high as 130 F. At this temperature, the heat of the liquid 40 above minus 40 F. is 38.69 B. t. u. per lb. of refrigerant. Taking the evaporating temperature to be 40 F. andassuming the vapor to be superheated to 60 F., the heat content of the vapor leaving the cooling coils will be 85.65 B. t. u. per

45 lb. The cooling effect of refrigerant in this case is 46.96 B. t. u. per lb. If, however, the liquid is cooled to 100? F. instead of 130 F., the heat content is 31.16 B. t. u. per lb. In this case, the cooling effect is 54.49 B. t. u. per 1b.; so that the cool- 50 ing effect per pound of refrigerant is increased approximately 16%. This means that the compressor displacement must be 16% greater and the power requirement is also greater, in the first case, for a given cooling load.

55 In accordance with my invention, I provide, in

addition to the usual condenser, an auxiliary cooler, such as a coil in which the refrigerant is further cooled more nearly to the temperature of the cooling fluid after said refrigerant has been fully condensed in the condenser. I provide a 5 liquid receiver between the condenser and the auxiliary cooler and connect the inlet of the cooler to the liquid receiver below the liquid level therein, so that only condensed refrigerant is delivered to the auxiliary cooler.

The above and other objects are effected by my invention, as will be apparent from the following description and claim taken in connection with the accompanying drawing, forming a part of this application, in which: 15

Fig. 1 is a diagrammatic view of a refrigeration system embodying my novel condensing and cooling apparatus; and,

Fig. 2 is a sectional view taken along the line 11-11 of Fig. 1. 20 Referring to the drawing in detail, I show a compressor 10 mounted on a bedplate 9 and driven by a motor II. Vaporous refrigerant which is compressed by the compressor I0, is conveyed through a conduit l2 to the condensing 5 and cooling apparatus indicated generally by the reference numeral l3. From the latter, it is delivered through a conduit It to an evaporator or cooling coil l5 and returned to the compressor I!) through a conduit I6.

The condensing and cooling apparatus I3 includes a condensing portion, a liquid receiver, and an auxiliary liquid cooler. I The condensing portion preferably comprises, as shown, a plurality of coils l1 arranged in parallel. The upper or inlet ends of the coils I! are connected to the conduit 12 through a header 18. The lower or outlet ends are connected through a header i 9 and a conduit 20 to a liquid receiver 2|, which may be formed as an integral part of the bedplate 9. The liquid cooler preferably comprises a coil 22 disposed at the side of the condensing coil H, the coils l1 and 22 being preferably carried in a frame structure 26, mounted on the bedplate 9, and thereby formed into a unitary structure. The lower or inlet end of the coil 22 is connected to the liquid receiver 2|, the communication with the receiver being effected, as by a pipe 23, below the surface of the liquid in the receiver so that only liquid refrigerant is admitted to the coil 22. The upper or outlet end of the coil 22 is connected to the conduit I4.

The condensing and cooling apparatus is provided with means for effecting flow of cooling medium to effect the condensing and cooling of the refrigerant. Preferably, a fan or blower 24 is provided and arranged to effect circulation of air flrst into contact with the coil 22 and then into contact with the coils l'l, which is to the left as seen in Fig. l, and indicated by the dotted line arrows. The fan 24 may be driven by the motor II.

The operation of the above described apparatus is as follows:

Vaporous refrigerant is compressed by the compressor I and delivered through the conduit i2 and the header it to the condensing coils II. The refrigerant is condensed as it flows through the coils I1 and is delivered through the header l9 and the conduit 20 into the receiverll. In the latter, the condensed refrigerant is added to the body of liquid whose variable level or surface is indicated at 25, and then flows through the pipe 23 to the cooling coil 22. The liquid refrigerant is cooled in the liquid cooler nearly to the temperature of the cooling air. The cooled refrigerant is then conveyed through the conduit M to the evaporator or low pressure side of the refrigerating system at substantially the temperature to which it is cooled in the liquid cooling coil 22. The refrigerant vaporized in the evaporator is withdrawn therefrom, through the conduit I 6, by the compressor i0.

From the above description, it will be seen that I have provided condensing and cooling apparatus wherein a definite cooling effect is applied to the refrigerant after it is condensed, independently of the liquid level in the receiver. The arrangement of the liquid receiver between the condenser and the liquid cooler, with the liquid cooler connected to the receiver below the liquid level in the latter, assures that only liquid refrigerant will be admitted to the liquid cooler, thereby providing for the cooling of a constant quantity of liquid refrigerant. The arrangement of the liquid cooler ahead of the coil l! in the path of the cooling air provides the lowest temperature of liquid refrigerant delivered to the evaporator.

While I have shown-my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of 10 various changes and modifications without departing from the spirit thereof, and I desire, 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 claim.

What I claim is:

In refrigerating apparatus, the combination of means for compressing refrigerant, a condensing coil for condensing the compressed refrigerant, a liquid receiver connected to the condensing coil and receiving refrigerant therefrom, a liquid cooling coil having its inlet connected to the liquid receiver below the liquid level therein for further cooling the liquid refrigerant, said condensing and liquid cooling coils being disposed adjacent each other in side-by-side relation, means effecting forced circulation of air for cooling in contact first with said liquid cooling coil and then in contact with said condensing coil, an evaporator, means for conveying liquid refrigerant from said liquid cooling coil directly to said evaporator at a temperature substantially as low as the temperature to which it is cooled in said liquid cooling coil, and means for conveying refrigerant from said evaporator to said compressing means.

LEWIS B. SMITH.

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