US2181221A - Refrigeration - Google Patents

Description

N. WIDELL REFRIGERATION Nov. 2 8, 1939.

Filed March 26,

INVENTOR.

M ATTORNEY.

Patented Nov. 28, 19,39

PATENT ori-ics Nils Widell, Stockholm, Sweden, assignor, by

menne assignments, to- Servei, Inc., Dover, Del., a corporationof Delaware sppucsunn mmh as, 1935, serial No. 13,013 In Germany March 29, 1934 1s claim.

My invention relates to refrigeration and more particularly to control of refrigeration tempera- It is an object of my invention to provide for control of refrigeration temperature without affecting the process or apparatus involved in producing the refrigeration.

It is another object to provide for temperature cooling source.

A further object is to provide for temperature control of a refrigerator including a continuous absorption refrigeration apparatus having a ,substantially constant heat input.

control of a refrigerator having an uncontrolled My invention, together with the objects and ad,

.- vantages thereof, will be fully understood upon reference to the following description and accompanying drawing in which:

The figure shows more or less schematically a refrigerator embodying my invention.

Referring to they drawing, a refrigerator cabinet Il provides a thermally insulated storage compartment II accessible by means of a door I2. In the upper .part of the refrigerator compartment I I is a cooling element I3 oi an absorption refrigeration apparatus like that, 'for instance, disclosed in U. S. Patent 1,609,334 to von Platen et al.v In

. the refrigerator cabinet I there is also an appaalcohol burner.

The operation of the refrigeration apparatus may be fully understood by reference to the disclosure of said U. S. Patent.1,609,334. Briey,

, however, an apparatus of this general type includes a generator and an absorber through and between which circulates a solution of refrigerant, such as ammonia, in an absorption liquid, such as water. 'In the generator, vaporous refrigerant is expelled from solution by heat. I'he vaporous refrigerant is liqueed in a condenser and the liquid conducted to an evaporator. The evaporator is interconnected with the absorber for circulation therebetween of an inert auxiliary gas as, for instancehydrogen. Inthe evaporator, liquid refrigerant evaporates and diffuses into' the hydrogen, producing a refrigeration eect. In the absorber, refrigerant-@por is absorbed into solution out of the inert gas, thus maintaining the partial pressure of refrigerantvapor suillciently low to permit continued evaporation of refrigerant in thefievaporator. It will be understood that the nature of the refrigeration apparatus or process is not the 5 subject of this invention.

Again referring to the drawing, air in the refrigerator compartment II is cooled by circulation in thermal exchange relation with the evaporator or cooling element Il. If operation of the refrigeration apparatus, of which the cooling eley ment I3 is a part, is not controlled, as in case the burner I'I is an ordinary continuously operating oil burner, the temperature in the refrigerator storage compartment II may be reduced below/av minimum value desirable for proper preservation of foodstuffs or other substances which may be stored in the refrigerator. Even through the refrigeration apparatus may be operated vwith the cooling element Ilat a substantially constant temperature, it will be understood that the temperature in the storage compartment] I is subject to considerable change depending upon variations in heat leakage upon change inair temperature outside of the refrigerator and intraduction into the storage compartment of material containing various quantities of heat. ,4

In order to prevent the temperature in the storage compartment II from becoming lower than a given value, I provide a vaporization-cony densation structure including acondenser portion I8, aA vaporization portion I 9, an accumulation vessel' 20, and a thermostatically operated valve 2|. The condenser portion I8 is located within the refrigerator storage compartment II and is provided with a suitable heat transfer surface formedl by ilns 22. The vaporization porv tion I9 may advantageously be formed as a `pipe coil and located around the generator heating iluey I6 at a point above thegenerator I5. The 40 upper end of the coil I9 is connected by a conduit 23 to the upper 'part of the condenser I 8. The lower end of the vaporization coil I9 is connected to the accumulation vessel 20. The lower part of the condenser I 8 is connected to the ac- 45 cumulation vessel 20 by means of a conduit 24. The thermostatically operated valve 2| is constructed and arranged to control the flow '..of liquid from the condenser I8 through the conduit 24 into the accumulation vessel 20. The 50 valve 2| may be of any desired type as a hermetically sealed valve operated by an expansible uid thermostat including a sensitive bulb 25 which is located in the refrigerator storagecompartment II. Such a thermostatic `valve is shown in an application for Letters Patent Serial Number 332,162 of W. T. Hedlund, filed January 12, 1929, now Patent No. 2,044,609, granted June 16, 1936. For the present purpose, the valve would be arranged to open rather than close upon decrease in temperature.

The just described vaporization-condensation member or circuit contains a suitable uid adapted to condense to liquid in the condenser I8 and vaporize into gas in the coil I9. Heat of vaporization is added to the uid in the coil I9 and heat of condensation is given up by the fluid in the condenser I8, wherefore the fluid may be referred to as a heat transfer fluid. The thermostatic valve 2| is preferably adjustable, as known, and is arranged to open when a desired minimum temperature is reached -in the refrigerator storage compartment I I in which the thermostat bulb is located. It will lbe understood that the vaporization coil I9 may be heated in any desired manner. It is desirable to maintain the temperature of the vaporization coil I9 at a temperature above that of the air and it is for this purpose arranged in thermal transfer relation with the flue I6 above the generator I5 where it is subject to the temperature of the combustion gas.

In operation, assume that the temperature in the refrigerator compartment I I has reached a predetermined minimum value as, for instance, 34 F. The valve 2I has been adjusted to open at this temperature so that liquid, which has been formed by condensation in the condenser I8, ows through conduit 24 into the accumulation Vessel 20. cumulation vessel 20 into the lower end of the vaporization coil I9 which is heated by the flue I6. The liquid is vaporized in coil I9 and the vapor flows through conduit 23 into the condenser I8. In this manner, heat is conducted by the heat transfer fluid from the flue I6 into the refrigerator storage Acompartment II. This influx of heat into the compartment II prevents the temperature therein from decreasing below the desired minimum value of 34 F. Upon continued influx of heat, the temperature in the compartment II rises above the said Value of 34 F. so that the thermostatic valve 2I closes, cutting off flow of liquid from the condenser I8 to the accumulation vessel 29. Liquid continues to vaporize in the coil I9 until there is no more fluid in liquid phase in this part of the device, Whereupon there is no further transfer of heat into the storage compartment.

By heating the vaporization coil I9 more or less directly by the source -of heat input, the burner I1, I maintain a greater temperature difference between the vaporization and condensation portions of what may be called the heat influx device and thereby obtain greater heat transmission into the refrigerator than if the vaporization coil I9 were subject to the temperature of the air outside of the refrigerator as is possible. This greater temperature differential between the vaporization and condensation portions of the cycle makes possible a smaller condenser, that is, the necessary heat transfer surface of the condenser I8 is an inverse function of the temperature differential between the condenser I8 and the vaporization coil I9. I may also make the vaporization coil I9 of sufllciently small internal diameter so that heated liquid is raised by thermal siphonic action upwardly through the coil I9 and conduit 23 into the condenser I8. In

this case the heat transferred is the heat of the The liquid flows from the acliquid between the temperatures of the condenser I8 and the vaporizing coil I9 plus the heat of vaporization of the vapor which causes the liquid circulation.

It will be understood that various changes may' be made within the scope of my invention which is therefore not limited to that which is shown in the drawing and described in the specification but only as indicated in the following claims.

What is claimed is:

l. In a refrigerator having a thermally insulated storage compartment, a refrigeration apparatus including a cooling element in said compartment, and a vaporization-condensation structure including a condenser in said storage compartment, said structure forming a circuit separate from said refrigeration apparatus, means for regulating flow of fluid in said structure responsive to temperature in said storage compartment, and a common source of heat for said refrigeration apparatus and said vaporization-condensation structure.

2. Controlling a refrigerator by heating a refrigerant to be condensed and evaporating the refrigerant, and off-setting the cooling effect thereby instigated by vaporizing a separate fluid due to the same heat source to a temperature above atmospheric and condensing the last named fluid to reject heat and provide a rise of temperature'counteracting said cooling effect.

3. Controlling a refrigerator having a space to be cooled by heating a refrigerant to be condensed and evaporating vthe refrigerant in heat exchange relation with the space to be cooled, offsetting the cooling effect thereby instigated by vaporizing a separate fluid due to the same heat source to a temperature above atmospheric and condensing the last named fluid to reject heat and provide'a rise of temperature counteracting said cooling effect, and controlling the extent of offsetting heat rejection in response to temperature of the space to be cooled.

4. In a refrigerator having a thermally insulated compartment, fluid containing absorption,

refrigeration apparatus to produce refrigeration and having a cooling element arranged to cool said compartment, a heated portion outside of said compartment and containing refrigerant fluid in an absorbent, a heat source for said heated portion, means whereby heating of said heated portion causes cooling of said cooling element, and means `providing a fluid path, in addition to the paths of flow of fluid in the apparatus utilized to produce refrigeration, for conducting heat from said heat source into said compartment, whereby said heat source serves as a common heat source for the production of refrigeration in said compartment and transfer of heat thereto.

5. In a refrigerator having a storage compartment in which a cooling effect is produced, a Vaporizer located outside said compartment for vaporizing fluid, a member arranged in thermal transfer relation with said compartment, means providing a path of flow for vaporized fluid from said vaporizer to said member to conduct heat directly into said compartment, means to provide a liquid barrier between the vaporizer and said l fluid at a place of vapor expulsion, condensing vaporized fluid to liquid at a place of condensation, and flowing liquid from the place of condensation into thermal transfer relation with a medium to be cooled and there vaporizing the liquid to produce a refrigerating effect, the improvement which consists in simultaneously flowing vaporous fluid into thermal transfer relation with said medium to be cooled and there condensing the fluid to counteract said refrigerating effect, and controlling said flow of vaporous fluid to control said counteraction.

7. In a refrigerator as set forth in claim 4, means for controlling flow of fluid in said path.

8. In a refrigerator having a thermally insulated storage compartment, continuous absorption refrigeration apparatus including a generator, a cooling element in said compartment, and a substantially constant source of heat for causing expulsion of refrigerant vapor from an absorbent in said generator the expelled refrigerantvapor being liquefied in said apparatus and flowing to said cooling element for vaporization therein, and a Vaporization-condensation structure including a condenser in said storage compartment, a vaporizer arrangedto be heated by said source of heat, conduits connecting said vcondenser and vaporizer and forming therewith a circuit adapted to contain a volatile fluid, and a thermostatically operated valve for regulating flow of fluid in -said circuit responsive to temperature in said storage compartment.

9. In a refrigerator having a thermally insulated storage compartment, continuous absorption refrigeration apparatus including a generator, a cooling element in said compartment, and a substantially constant source of heat for causing expulsion of refrigerant vapor from van absorbent in said generator, the expelled refrigerant vapor being liquefied in said apparatus and owing to said cooling element for vaporization therein, and a vaporization-condensation structure including a condenser in said storage compartment, a vaporizer without said compartment,` conduits connecting said condenser and vaporizer and forming therewith a circuit adapted to contain a volatile fluid, and means for regulating flow of fluid in said circuit responsive Vto temperature in said storage compartment.

10. In a refrigerator having a thermally insulated storage compartment, absorption refrigeration apparatus including a cooling element constructed -and arranged for cooling said compartment,'and a generator in which refrigerant vapor is expelled out of an absorbent by heating, Y the expelled refrigerant vapor being liquefied in' said apparatus and floWing-tosaid cooling element` for vaporization therein, and means for controlling -the temperatureof said compartment including a first fluid containing member constructed and arranged for heating said 'compartment, a second heated fluid containing member outside of said compartment,y connections for circulation of heat transfer fluid between said members, and means operable to prevent flow of fluid to said heated member.

11. A refrigerator as set forth in claim 10 in which said flow preventing means is automatically operative responsive to temperature in said compartment.

12. A .refrigerator as set forth in claim 10 in which said fluid containing members and connections constitute a vaporization-condensation structure.

13. A refrigerator as set forth in claim 10 in which said fluid containing members and connections constitute a vaporization-condensation structure, and said flow preventing means is thermostatically operated responsive to temperature in said compartment and causes liquid to remain in said rst member forming the condensation portion of said structure. 14. In a refrigerator cooled by a continuous absorption type refrigeration apparatus comprising a plurality of interconnected parts including a cooling element and a generator and having a substantially constant source of h-eat for causing expulsion of refrigerant vapor from an absorbent in said generator, the expelled refrigerant vapor being liquefied in said apparatus and flowing to said cooling element for vaporization therein, thatimprovement which consists in controlling the refrigeration temperature by taking interconnected parts including a 'generator in which refrigerant vapor is expelled out of an'4 absorbent by heating and an evaporator into which such expelled refrigerant flows after being liquefied, means to heat said generator above atmospheric temperature, a heat rejecting condenser situated so that rejected heat is transferred to a part` of the refrigeration apparatus to counteract cooling effect of said refrigerating apparatus, and means utilizing said generator heating means for feeding fluid to be condensed to said condenser.

16. A refrigerator comprising a cabinet, fluid containing absorption refrigerating apparatus for cooling said cabinet comprising a plurality of interconnected parts including a generator in which refrigerant vapor Ais expelled out of an absorbent by\heating and an evaporator into which such expelled refrigerant flows after being liquefled, means to heat said generator above atmospheric temperature, a heat rejecting condenser situated so that rejected heat is transferred to a part of the refrigeration apparatus to counteract cooling effect of said refrigerating apparatus, means utilizing said generator heatlng means for feeding fluid to be condensed to said condenser, and temperature responsive means for controlling the feed for fluid to said condenser. y

17. In a refrigerator having a thermally insulated compartment, absorption refrigeration apparatus including a cooling element arranged for cooling said compartment and a generator located outside said compartment and in which ducting means.

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