US2267893A - Refrigeration - Google Patents

Description

Dec. 30, 1941. H. K. BERGHOLM REFRIGERATION Filed 'Dec. 19, 1939 2 Sheets-Sheet 1 Dec. 30, 1941. H. K. BERGHOLM REFRIGERATION Filed D90. 19, 1939 2 Sheets-Sheet 2 lfirfi lomw.

Patented Dec. 30, 1941 REFRIGERATION Harry K. Bergholm, Stockholm, Sweden, assignor,

by mesne' assignments,, to Serve], Inc., New York, N. Y., a corporation of Delaware Application December 19, 1939, Serial No. 309,969 In Germany December 22, 1938 9 Claims.

My invention relates to refrigeration and more particularly to a refrigeration system employ.- ing evaporation of refrigerant fluid in the presence of an inert gas or auxiliary agent.

In apparatus of this type it is customary to provide a gas heat -exchanger for exchanging heat between cold gas flowing from an evaporator to an absorber and warm gas flowing to the evaporator from the absorber. In many instances the heat exchanger is arranged so that it extends through the wall of a refrigerator cabinet. In order to obtain the greatest possible cooling effect from the relatively 0001 gas flowing from the evaporator, it is preferable to connect the heat exchanger in such a manner that this gas flows in contact with the outer wall of the exchanger. With this arrangement the portion of the heat exchanger within the refrigerator cabinet aids in eflecting space cooling. The portion of the heat exchanger outside of the cabinet is, however, contacted by atmospheric air and there is a tendency for water vapor contained in such air to condense on the relatively cold outer surface of the heat exchanger. Any condensation forming on the portion of the heat exchanger outside the cabinet is objectionable.

In accordance with the invention I provide a jacket around the portion of the gas heat exchanger disposed outside of the refrigerator cabinet and supply this jacket with relatively warm gas flowing from the absorber. The jacket may also surround a portion of the conduit through which cold gas'is conducted from the heat exchanger to the absorber. With this arrangement atmospheric air does not contact relatively cold parts of the refrigeration apparatus outside of the cabinet whereby condensation of water vapor is avoided. A further advantage resulting from this arrangement is that increased heat transfer surface is provided between the warm and cold gases so that the effieiency of the apparatus is improved. Further, the warm absorption liquid flowing from the generator to the absorber may be arranged to flow in thermal relation with the jacket, whereby heat'transfer is effected between the liquid and the cold gas flowing from the evaporator.

The above and objects and advantages of the invention will be more fully understood upon reference to the following description and accompanying drawings forming a part of this specification, and of which:

, Fig. l more or less diagrammatically illustrates refrigeration apparatus embodying the invention; and

Fig. 2 illustrates another embodiment of the invention. Referring to Fig. 1, a generator Ill includes a flue ll surrounded by a jacket l2.

The flue II is arranged to be heated in any suitcoil. the lower end of which is connected by a 24 and forms one wall of the space 2|.

conduit 20 with a space 2| formed within one end of a gas heat exchanger 22. The gas heat exchanger 22 includes an outer shell 23 which is closed at one end by a header 24. A plate 25 is disposed within the shell adjacent to the header A plate 26 is disposed at the other end of the shell, and a plurality of tubes 2'! extend through the plates 25 and 26. A jacket 28 is arranged around the portion of shell 23 which extends Within and through the insulated wall I 8. As shown in Fig. 1', the tubes 2'! connect the space 2| with the interior of jacket 28.

A conduit 29 connects the upper end of the evaporator with the space 30 formed within the shell 23 between the plates 25 and 26 and outside of the tubes 21. Adraln conduit 9 is connected to the lower part of the evaporator and to the space 30. A conduit 3| extends downwardly from theother end of space 30 and communicates with a vessel 32. The jacket 28 is provided with a downwardly extending leg or auxiliary jacket 33 which surrounds a portion of conduit 3|.

Thelower end an absorber 34 is connected to the upper part of vessel 32, and the upper end of the absorber is connected by a conduit 35 with the leg 33. A conduit 36 connects the lower part of vessel "32 with the inner-passage 31 of a liquid heat exchanger 38. The other end of the inner passage is connected to the bottom of a coil 39 arranged in heat exchange relation with the flue A conduit 40 connects the upper end of coil 39 with the upper part of the generator ID. A conduit 4| connects the lower part of the generator with the outer passage 42 of the liquid heat exchanger 38. A conduit 43 connects the other end of/pipe 42 with the upper part of the absorber 34," \g

A pressure vessel 44 is connected to the condenser IG and to the gas circuit in a manner well known in the art, whereby the total pressure in the apparatus is increased with increase in air temperature to insure condensation of refrigerant vapor in the condenser. As shown',a conduit 45 connects the lower end of condenser I6 with one end of vessel 44, and a conduit 46 connects the other end of vessel 44! to conduit 3| of the gas circuit.

The operation of the above described device is generator Ill. Refrigerant vapor is liquefied in condenser l6 and the liquid flows through conduit into the upper part of the evaporator l9.

Inert gas enters the lower part of evaporator I! through conduit 20 and flows upwardly and counter-current to liquid refrigerant. Liquid refrigerant evaporates and diffuses into inert gas to produce a refrigerating effect with consequent absorption of heat from evaporator l3 and its surroundings.

The resulting mixture of refrigerant and inert gas, that is, gas rich in refrigerant, flows from evaporator 19 through conduit 23 into space 30 in gas heat exchanger 22. The rich gas mixture cools shell 23 whereby heat: is abstracted from the space within the cabinet. From the space 30 the rich gas mixture flows through conduit 3| and the upper part of a 'vessel 32 into the lower end of absorber 34. Absorption liquid weak. in refrigerant enters the upper part of absorber 34 through. conduit -43 and flows downwardly through the absorber. The absorption liquid absorbs refrigerant vapor from the inert gas, and inert gas weak in refrigerant flows upwardly through conduit 35.

Heat is liberated with absorption of refrigerant vapor in absorber 34, so that the inert gas flowing from absorber 34 through conduit 35 is relatively warm. The warm weak gas flows through the leg 33 into the main part of jacket 23, and.

inner surfaces of the outer walls are contacted by warm gas flowing from absorber 34. The leg 33 or extension of jacket 28 prevents atmospheric air from contacting the upper part of conduit 3|. By the time the rich gas mixture reaches the. lower part of conduit 3| not enveloped. by

leg 33, its temperature hasbeen raised suificientlyby heat exchange with warm gas in the jacket so that condensation. thereon is avoided.

Absorption liquid enriched in refrigerant flows from the lower part of absorber 34 into vessel 32,

and thence through conduit 36 and inner passage 31 of liquid heat exchanger 33 into the lower end of coil 39. Liquid is raised by thermosiphon tube 40 into the upper part of generator II. The refrigerant vapor expelled out of solution from generator ll, together with refrigerant vapor enstorage space, refrigeration apparatus includingtering through thermosiphon tube 4|, flows upwardly to condenser l3, as explained above.

The absorption liquid from which refrigerant has been expelled flows from generator l0 through conduit 4|, outer passage 42 of liquid heat exchanger 33, and conduit 43 to the upper part of absorber 34. This circulation of absorption liquid results from the raising of liquid by thermosiphon tube 43.

The circulation of gas in the gas circuit described above is due to the difference in specific weight of the columns of rich and weak gas formed by gas flowing toward and away from absorber 34. Since the rich gas is heavier than the weak gas, a force is developed or produced for causing circulation of the gas.

The embodiment illustrated in Fig. 2 is generally similar to that shown in Fig. 1 and differs therefrom in that the leg 33:; of jacket 23 extends downwardly around the conduit 3| to a point below the upper end of absorber 34. Also, the conduit 43 is connected to the lower end of jacket 23 so that a pool of. relatively warm absorpin'on liquid is formed in the lower end of the jacket. with this arrangement weak absorption liquid from generator I first flows in heatexchange relation with rich gas in conduit 3| and thence into the upper end of absorber 34.

Not,only is a greater portion of the conduit 3| enclosed within a heating lacket in the embodi mentof Fig. 2, but heat exchange is also effected between the weak absorption solution flowing from the generator to theabsorber and the rich gas mixture flowing from the evaporator to the.

absorber.

In other respects. the embodiment of Fig. 2 is like l with parts referred to by the same reference numerals, and further description thereof will not needlessly be repeated here.

While several embodiments of the invention have been shown and described, such variations and modifications are contemplated as fall within the true spirit and scope of the invention. as pointed out in the following claims.

What is claimedis: 1. A refrigerator having a thermally insulated an evaporator arranged in thermal transfer relation with said space and inwhich refrigerant evaporates in the presence of an inert gas, means including a gas heat exchanger having an inner passage to provide: a first path oiv flow for conducting gas to said evaporator and an. outer passage to provide a second path of flow for cone ducting gas from said evaporator, a part of said gas heat exchanger being outside said space, and structure providing an enclosure about the. portion of the outer passage. of saidheat exchanger disposed outside said space, said enclosure forming a part of the first path of flow through which gas is conducted to said evaporator.

2. A refrigerator having a thermally insulated storage space/refrigeration apparatus containing a plurality of fluids and including an evaporator in which refrigerant fluid evaporates in the presence of an auxiliary fluid, said evaporator being arranged in thermal relation with said space, means providing a first path of flow for. gas flowing to said evaporator, means providing. a second path of flow for gas flowing from said evaporator, a part of said second means being disposedwithinapartofsaidflrstmeansto form a heat exchanger, a part of said heat exchanger being disposed outside said space, structure forming an enclosure about the part of saidheat exchanger outside said space, and means to circulate warm fluid in the system through said enclosure.

3. In an absorption refrigerating apparatus, a refrigerator cabinet having thermally insulated walls, an evaporator disposed within said cabinet, a gas heat exchanger extending through one of said walls, said heat exchanger including an outer shell, means connecting said shell to the outlet of said evaporator whereby cold gas is supplied to the space within said shell, an absorber disposed outside said walls, a jacket around the portion of said shell outside said walls, and means for supplying warm gas from said absorber to said jacke 4. In an absorption refrigeration app ratus, a refrigerator cabinet having thermalb'insulated walls, an evaporator disposed within said cabinet, a gas heat exchanger extending through one of said walls, said heat exchanger including an outer shell and an inner conduit, means connecting said shell to the outlet of said evaporator whereby cold gas is supplied to the space within said shell and around said conduit, an absorber disposed outside said walls, a jacket around the portion of said shell outside said walls, means for supplying warm gas from said absorber to said jacket, one end of said conduit being connected to said jacket to receive gas therefrom, and means for conducting gas from the other end of said conduit to the inlet of said evaporator.

5. In an absorption refrigerating apparatus, a refrigerator cabinet having thermally insulated walls, an evaporator disposed within said cabinet, a gas heat exchanger extending through one of said walls, said heat exchanger including an outer shell, means connecting said shell to the outlet of said evaporator whereby cold gas is supplied to the space within said shell, an absorber disposed outside said walls, a conduit connecting said shell with the gas inlet of said absorber, ,a jacket around the portion of said heat exchanger outside said walls and around at least a portion of said conduit, and means for supplying warm gas from said absorber to said jacket.

6. In an absorption refrigeratingapparatus, 'a refrigerator cabinet having thermally insulated walls, an evaporator disposed within said cabinet, a gas heat exchanger extending through one of said walls, said heat exchanger including an outer shell, means connecting said shell to the outlet of said evaporator whereby cold gas is supplied to the space within said shell, an absorber disposed outside said walls, a conduit connecting said shell with the lower end of said absorber, a jacket around the portion of said shell outside said walls and around at least a portion of said conduit, the upper end of said absorber being connected to said jacket whereby warm gas within said shell and around said inner element,

an absorber disposed outside said walls, a conduit connecting said shell with the gas inlet of said absorber, a Jacket around the portion of said shell outside said walls and around at least a portion of said conduit, the upper end of said absorber being connected to said jacket whereby warm gas is supplied to said jacket, one end of said hollow element being connected to said jacket to receive gas therefrom, means for conducting gas from the other end of said element to said evaporator, a generator, and means for supplying warm liquid from said generator to said jacket, whereby the liquid is supplied to the upper end of said absorber.

8. In an absorption refrigerating apparatus, a refrigerator cabinet having thermally insulated walls, an evaporator disposed within said cabinet, a gas heat exchanger extending through one of said walls, said heat exchanger including an outer shell, means connecting said shell to the outlet of said evaporator whereby ,cold gas is V supplied to the space within said shell, an absorber disposed outside said walls and below said heat exchanger, a conduit having vertical extent connecting said shell with the lower end of said absorber, a jacket around the portion of said shell outside said walls and having a downwardly extending leg around at least a portion of said conduit, the upper end of said absorber being connected to said leg whereby warm gas is supplied to saidjacket, a generator, and means for supplying warm liquid from said generator to said leg, whereby the liquid is supplied to the upper end of said absorber.

9. Refrigeration apparatus including an evaporator in which refrigerant evaporates in the presence of an inert gas and means for conducting gas to and from said evaporator including a gas heat exchanger, at least a part of which is exposed to atmosphere, and having an inner passage for conducting gas flowing to said evaporator and an outer passage to conduct gas flowing is supplied to said Jacket, a generator, and means from said evaporator, and structure providing an enclosure about said portion of the gas heat exchanger exposed to atmosphere and forming a part of a path of flow for gas to saidinner passage. HARRY K. IBERGHOLM.

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