US2170656A - Refrigeration - Google Patents

Description

G. GRUBB REFRIGERATION Aug. 22, 1939.

Filed Aug. 12, 1936 INVENTOR, 19 $2.

Patented Aug. 22, 1939 UNITED STATES PATENT OFFICE REFRIGERATION -Application August 12, 1936,

Serial No. 95,492

In Germany August 27, 1935 17 Claims. (Cl. 62-118) This invention relates to refrigeration apparatus or systems of the non-continuous or intermittent or periodic type.

The purpose of the invention is to improve the 5 operation of systems of this type, and this is accomplished by the modification of a more or less standard intermittent system by the addition of a preferably separately hermetically sealed intermittent system, one or more parts of which are 10 in heat exchange relation with the first-mentioned system. More specifically, the added system includes a generator-absorber. in heat exchange relation with an absorption liquid circula-' tion circuit of the first system, or otherwise ar- 15 ranged so that such generator-absorber may be heated only by heat from an internal place of heating, that is, by heat of absorption transferred from the first system. By this arrangement, the production of refrigeration is rendered 2 morecontinuous than by means of one intermittent system alone, inasmuch as the components of the compound system operate alternately. Furthermore, the component parts of such a compound system can operate at difierent temperatures or temperature ranges and thus the heat receiving portions of the respective components can be utilized to absorb heat from different temperature compartments of a refrigerator cabinet or groups of refrigerator cabinets, or 30 other objects to be refrigerated.

In a preferred form of the invention I have applied the same to the character of system described in an application Serial No. 718,136 filed by Carl Georg Munters on March 30, 1934, Patent 35 No. 2,086,632 but it will be understood that the invention is not limited to the specific apparatus therein described. However, for purposes of description, it may be considered that the disclosure of said Munters application Serial No. 718,136 is 40 incorporated in this application. r

The present invention will be described in conjunction with the accompanying drawing showing a preferred form thereof more'or less diagrammatically, which drawing forms a part of this 45 specification.

Fig. 1 is a diagrammatic elevation view partly in cross section showing one embodiment of the invention; and

I Fig. 2 is a similar view of an alternative part 50 for some of the structure shown in Fig. 1.

The system shown in Fig. 1 includes an absorption liquidreservoir lil of sufficient volume to hold the bulk of absorption liquid in the system. This reservoir is preferably exposed to the cooling 55 influence of surrounding air. To one side of the reservoir I0 is a vessel l4 which maybe termed a generator or separator or be considered as a part of a vapor expeller. This vessel is not directly. heated, though it may be. In the embodiment illustrated, the contents of vessel II are heated 5 by a conduit 38, 33, 40 including a vapor lift coil 39 which is in heat exchange relation with a flue 4| which may be suitably heated as by a gas burner or by an electric heater disposed therein.

Between vessels l0 and I4 is a liquid heat exchanger l2 including inner and outer pipes forming heat exchange spaces for flow of liquid. The inner pipe of the heat exchanger is connected by a conduit l3 to the lower part of vessel I4, and is connected at its other end by a conduit II to the reservoir I0. These parts form a conduit for flow of liquid from the bottom part of vessel M to reservoir l0.

Connected to the top of reservoir I0 is a vertical conduit 2|, the upper end of which is connected to a vessel H] which is normally filled or substantially filled with liquid. Aconduit l5, I6, I 8 is connected to the lower part of reservoir l0 and extends upwardly to connect with vessel I9.

This conduit includes a horizontal loop l6 con- 5 stituting an absorption liquid cooling element having fins 63 for "increasing the heat transfer surface. Also connected to vessel I9 is a strong liquor conduit 33. Parts l5, l6, l8, l9, 2| and 33 constitute anabsorption liquid containing structure extending above reservoir Ill. This structure is connected to the liquid space of the absorption liquid containing partof the system so that; practically at all times, this structure is filled or substantially filled with liquid due to the fact that, these parts being exposed to atmosphere, the temperature of the fluid therein is such that for the pressure prevailing in the system and in view of the concentration of solution, all the gas can be dissolved and remain in solution form. 40

The bottom of pipe 33 is connected to the outer pipe of the liquid heat exchanger l2. A conduit 32 extends between the other end of the outer conduit of theheat exchanger and the lower part of an annular chamber 3|within vessel 9 formed between vertically disposed cylinders. Chamber 3| is closed at the bottom except for conduit connections and is open at the top. The upper edge of the inner cylinder provides an overflow edge. The central space 34 is connected at the bottom with a tube 24; This tube contains a liquid reac-. tion head for gas lift structure.

A conduit 28 is connected to the bottom of tube 24 and is connected to a gas lift coil 29 surrounding flue 4|. The upper end of coil 29 is connected by means of conduit 39 to the space 3|. A second conduit 25 is connected to the lower end of tube 24 and is' connected to a gas lift coil 26, the upper end of which is connected by a pipe 21 with the upper part of vessel l4. A vapor conduit 36 connects the upper part of vessel M with the space 34.

A volume variation vessel 22 is connected by means of conduits 23 and 3'! with the tube 24 and the vessel 9.

A conduit 44 extends upwardly within a rectifier jacket 46 to which is connected a condenser loop 45 having fins |1 thereon exposed to atmospheric air for cooling. The rectifier 46 is connected by means of a conduit 48 with an evaporator 49 situated within a space to be cooled denoted by the line 80.

Connected to the evaporator 49 is'a conduit adapted to receive residue absorption liquid from the bottom of the evaporator. A conduit 5| is connected to the tube 50 and is connected to a jacket 68. Connected to jacket 68 is an over fiow tube 5| which has a part 52 in heat exchange relation with the volume variation vessel 22 and which is connected to pipe I5 at 43. A pipe 42 is connected above point 43 to conduit l5 and is connected at a higher elevation to the conduit 31.

The operation of the part of the system so far described is set forth at length in the aforementioned application of Munters and will be here briefly described, reference being had to the aforesaid application for a more detailed description of operation if desired.

During a high pressure period heat is applied in the flue 4|. This causes generation of vapor in the three gas lift coils 26, 29 and 39. These are places of external heating. Coil 39 is merely a local circulator for the generator vessel l4. Coil 26 causes a lifting of liquid and vapor from the bottom of tube 24 to the upper part of vessel l4. In vessel l4 the vapor generated is separated from the liquid. The liquid flows downwardly within vessel |4, through conduit l3, through the inner conduit of the heat exchanger I2, and through conduit tothe reservoir II). From reservoir |0 liquid circulates upwardly through conduit 2|, through vessel |9, through conduit 33, through the outer space of heat exchanger |2', through conduit 32 and into space 3|. Liquid in space 3| is pushed upwardly therein due to the lifting of liquid and vapor by coil 29 and the liquid overflows into space 34 and down into tube 24 whence the liquid is returned to the vessel |4 by'means of coil 26. i

The expelled vapor passes through conduit 36 and flows upwardly through'the overflow liquid in vessel 9. The vapor thence flows upwardly through conduit 44 and is condensed in'condenser loop 45. Entrained Water vapor is removed from the refrigerant vapor in the analyzer.

sp'ace34 and the rectifier 4B and returns to the lower part of the system. Liquid'refrigerant is forced through conduit 48 'into the evaporator 49 where it collects. During this period there is little or no circulation'through conduit l5, lfi, |8. The expulsion of refrigerantvapor continues until the evaporator contains so much liquid re-' frigerant that there is overflow through conduits 50, 5| and 5|. Liquid overflow through conduits 5| and 5| consists at first 'of absorption liquid. This liquid flows in heat exchange relation with the volume variation vessel 22 at 52 but the absorption liquid is not vaporized. When,

however, substantially pure refrigerant overflows through conduit 5|, it becomes vaporized at point 52. The introduction of vapor from conduit 5| into conduit l5 causes a circulation to set up, which circulation of warm liquid may be utilized by means of a thermostat or through other means to shut off the heat to the generator, thereby closing the generating period.

When heat is shut off, the liquid in space 3| drops since the coil 29 is no longer effective, and as this liquid drops a corresponding colunm of liquid in conduit 42 recedes untilconduit 42 is devoid of liquid, whereupon gas has free entry into conduit l5 from the evaporator through conduits 48, 44, 31 and 42. Now an absorption period starts, which period is at reduced pressure. During this period a circulation is set up from reservoir I0 through conduit I5, loop l6, conduit I8, vessel l9, and downwardly through conduit 2|. The heat of absorption produced in the places of internal heating, conduits l5 and I6, is rejected from the absorber cooling coil l6.

So far the system described is one of a number of systems to which the invention may be applied.

The system so far described may be called the primary system. It may contain ammonia and ably treated as known in the art, or any of. various known solid absorbents, particularly those including an element of the halogen group. A plurality of fins 69 extend into and from the generator-absorber 6| so that there is good heat transfer relation between the cooling loop l6 and the generator-absorber and also heat transfer with respect to atmosphere.

Connected to the generator-absorber is a conduit 64 which is connected to a condenser 65, in turn connected to an evaporator 61 including a loop connected to a receiver 66. Conduit 64, on which the condenser fins 55 are arranged, passes through the previously described jacket 68 so as to be in heat exchange relation with overflow liquid from the evaporator 49 of the primary system. As may, for example, utilize methylamine.

Let us first consider the operation of the secondary system during the expulsion period of the primary system., Evaporator 61 contains the secondary refrigerant. Since there islittle or no circulation through loop l6 during this period the generator-absorber 8| can readily dissipate heat to the atmosphere, and thus the refrigerant is absorbed therein and flows from evaporator 61 through conduit 64 and into the generatorabsorber'. The refrigerant within evaporator 61 is thus vaporized and withdraws heat from the surroundings, producing refrigeration. The refrigeration supplied by evaporator 61 during this high pressure period of the primary system at least in part bridges the hiatus of evaporation in the primary system.. Inasmuch as the primary the refrigerant the secondary system During the absorption period of the primary system there is an intense circulation through conduits i5, i6 and l8- wherefore considerable heat is given ofi to the generator-absorber 6!. This causes expulsion of methylamine from .the absorbent and the .vapor is-condensed in con-, denser and accumulates in evaporator 61. If desired, the condenser may be placed behind the evaporator as is generally known in the art by the term dead end condenser, orthe evaporator may have a receiver-outside the refrigerated space so as to avoid undue'heating of the refrigerated space during theexpulsion-period of the secondary system.

It may be advantageous under certain circumstances to utilize an indirect system for the withdrawal of heat from the generator-absorber 6|. Fig. 2 shows a system for accomplishing: this in which the generator-absorber 6| is surrounded by a cooling coil 1|. This coil is connected to a dome 11 on a vessel which is in turn connected by means of a conduit 13 with an additional coil 14 surrounding the flue Al. The upper end of coil 14 is connected by means of a conduit 13 to a condenser 15 having fins 16 and which drains into the bottom of coil H. A pipe 18 connects dome 11 with the upper part of theconden'ser. Let us assume that liquid iscontained in this separate indirect cooling system to the height indicated at 19. The vessel '12 and coil 14 are therefore filled with liquid. During the heating period of the primary system vapor is driven off in coil 14 and liquid and vapor are carried upwardly in conduit 13 to the condenser '15.. The

' liquefied fluid flows to the coil 11 where it is partially vaporized and absorbs heat from the gene erator-absorber 6|. The coil 1| acts as a gas lift device and the liquid and vapor are'lii'ted up to the dome 11 whence the vapor passes through conduit 18 to be re-condensed and the liquid passes through vessel 12 to be re-circulated by the gas lift coil 14.

When the heating of the flue ll is discontinued, that is, during the absorption period of the primary system, the vapor lift effect of coil 14 is discontinued. Thus no more liquid is supplied through conduit 13 to condenser 15, and coil 1| is quickly depleted of its liquid content, wherefore this system becomes ineffective to transfer heat from the generator-absorber.

It will be obvious to those skilled in the art that the invention is not limited to' the specific apparatus disclosed.

What is claimed is:

1. Refrigeration apparatus including a system having alternate periods of expulsion of refrigerant from absorbent and evaporation of refrigerant and including vessels and conduits forming at least two circuits for circulation of absorption liquid so constructed and arranged that during periods of refrigerant'expulsion absorption liquid circulates in one of said circuits without producing circulation in the other of said circuits, an evaporator, an absorber, a conduit connecting said evaporator and said absorber, and said absorber being in heat exchange relation with a part of the other of said circuits.

2. Refrigeration apparatus including a system having alternate periods of expulsion of refrigerant from absorbent and evaporation of refrigerant and including vessels and conduits forming at least two circuits for circulation of absorption liquid so constructed and arranged that during periods ofrefrigerant expulsion-absorption liquid circulates in one of said circuits without producing circulation in the other of said circuits, an evaporatonan absorber, a conduit connecting said evaporator and absorber, said evaporator and absorber constituting a secondary-system separate from the system-including said circulation circuits, and said absorber being in heat exchange relation with a part of the other of said circuits.

3. Refrigeration apparatus including a system having alternate periodsof expulsion of refrigeranttfrom absorbent and evaporation of refrigerant and including vessels and conduits forming at least two circuits for circulation of absorption liquid so constructed'and arranged that during periods of refrigerant expulsion absorptionliquid circulates in one of said circuits without producing circulation in the other of said circuits, an evaporator an absorber,a solid absorbent in said absorber, a conduit connecting said evaporator and said absorber, and said absorber being in heat exchangerelation with a part of the other of said circuits.

' 4; Refrigeration apparatus including a system having alternateperiods of expulsion of refrigerant from absorbent and evaporation of refrigerantand including vessels andconduits forming at least two circuits for circulation of absorbtion absorber, andsaid generator-absorber being in heat exchange relation with of said circuits. Y

5. Refrigerating apparatus including at least two separately hermetically sealed intermittent absorption systems, one of said systems having at least two alternately heatedcircuits for circulation of absorption liquid and the other of said systems having a generator-absorber in heat exchange relation with one of said circuits.

6. Refrigerating apparatus as set forth in claim 5 in which hot. fluid flowing in one system is cooled by cold fluid flowing in another of the systems.

'7. In absorption refrigeration apparatus of the kind having aiternateperiods of absorption at low pressure and expulsion. of refrigerant from solution at higher pressure, a generator, a first evaporator, a storage reservoir of sufllcient volume to.hold the bulk of absorption liquid in the system, members forming ajcircuit for circulation of liquid through said reservoir'including'an upwardly extending conduit, means to conduct vapor from said evaporator to said circuit, a second evaporatoaa generator-absorber in heat exchange relation with said circuit, and a conduit connecting said second evaporator with said generator absorber.

a. In a refrigeration syste'Yn of the kind having low pressure periods of -refrigerant evaporation and absorption alternating-with higher pressure periods of vapor expulsion and including a main circuit and an auxiliary circuit for circulation of absorptionliquid in the latter of which there is substantially no circulation of absorption liquid during the higher pressure periods of vapor expulsion, the improvement whichconsists in utilizing the heat of absorption in said auxiliary circuit during the lower pressure periods of refrigerant evaporation to expel refrigerant from' an absorbent.

a. part of the other pulsion, the improvement which consists inutilizing the heat of absorption in said auxiliary circuit during the lower pressure periods of refrigerant evaporation to expel refrigerant from an absorbent and utilizing the refrigerant so expelled to produce evaporation when such heat of absorption is not produced.

10. In refrigeration apparatus including a system having alternate periods of expulsion of refrigerant from absorbent and evaporation of refrigerant and including vessels and conduits forming a circulation circuit for absorption liquid, an evaporator, an absorber, a conduit connecting said evaporator and said absorber, and said absorber being in heat exchange relation with a part of said circuit.

11. Refrigeration ,apparatus including a first evaporator, a generator-absorber, a vapor conduit connecting said generator-absorber with said evaporator, a second evaporator, means for supplying liquid to said second evaporator, a liquid overflow conduit connected to said second evaporator, said liquid overflow conduit and said vapor conduit being in heat exchange relation.

12. Refrigeration apparatus including a first circuit for circulation of absorption liquid, a second circuit for circulation of absorption liquid, heating means to cause circulation in one of said circuits without producing circulation in the other of said circuits, and a heat transfer system connected between said other of said circuits and a space to be cooled.

14. Apparatus as set .forth in claim 13 in which the cooling system for the generator-absorber is a fluid containing system and in which there is a common heating means for fluid in said system and for the expeller.

15. In refrigeration apparatus including a system having alternate periods of expulsion of refrigerant from absorbent and evaporation of refrigerant and including vessels and conduits forming a circulation circuit for absorption liquid,

an evaporator, an absorber, a conduit connecting said evaporator and said absorber, said evaporator and absorber constituting a secondary system separate from the system including the circulation circuit, and said absorber being in heat exchange relation with a part of said circuit.

16. A method of refrigeration which includes flowing absorption liquid alternately in different paths having separate places of external and internal heating respectively to carry out an intermittent absorption refrigeration cycle, and utilizing heat from the place of internal heating to supply input for an alternate intermittent refrigeration process.

17. Refrigeration apparatus including a first intermittent absorption refrigeration system having places of external and internal heating separated and in alternate paths of absorption liquid flow, and a second intermittent refrigeration system operated by heat input from said place of internal heating.

GUNNAR GRUBB.

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