US2165138A - Refrigeration - Google Patents

Description

July 4, 1939.

G. G RUBB REFRIGERATION Filed June 16, 1936 INVENTOR.

kw ATTORNEY.

Patented July 4, 1939 UNITED STATES PATENT OFFICE REFRIGERATION Application June 16, 1936, Serial No. 85,481 In Germany June 20, 1935 1'1 Claims.

My invention relates to refrigeration, and more particularly to apparatus for maintaining an enclosed space substantially at a desired temperature with the aid of refrigeration apparatus operated by heat.

The object of my invention is to provide an improved apparatus for maintaining an enclosed space substantially at a desired temperature with the aid of heating means and refrigeration apparatus operated by heat.

Another object of my invention is to provide such apparatus for maintaining an enclosed space substantially at a desired temperature in which the refrigeration apparatus, after not .5 being in operation, shall be effective to cool the enclosed space in the minimum length of time after the operation of the apparatus is initiated.

Further objects and advantagesof my invention will become apparent from the following de- 30 scription taken in connection with the accompanying drawing in which Fig. 1 is a diagrammatic illustration of an embodiment of my invention for heating an enclosed space and refrigeration apparatus operated by heat with gas 35 burners; and Fig. 2 is a fragmentary sectional view of a modification of parts of the embodiment shown in Fig. 1.

Referring to Fig. 1 of the drawing, I have shown a cooling element l0 and a heater ll ar- 30 ranged within an enclosed space l2, such as, for

example, the thermally insulated storage compartment of a refrigerator cabinet l3. It is to be understood, however, that other arrangements of a cooling element and a heater can readily be 35 made for maintaining an enclosed space substantially at a constant or desired temperature.

The cooling element Ill forms part of refrigeration apparatus comprising a generator l4 containing a refrigerant in solution in absorption liq- ;0 uid. Although I do not wish to be limited therei to, the refrigerant may be ammonia and the absorption liquid may be. water. A main gas burner I5 is disposed below the generator and projects its flame l5 into the lower end of a flue l6 which 45 extends upward through the generator. The heat applied to the generator and its contents by the main gas burner l5 expels the ammonia out of solution, and the ammonia vapor thus generated flows upward through an air cooled rectifier I1 50 which condenses any water vapor which may be carried upward with the ammonia vapor. The water condensed in the rectifier drains back to the generator, and the ammonia vapor flows upward to an air cooled condenser 18 comprising a 55 coil provided with a plurality of heat dissipating elements, or cooling fins l8. The ammonia is liquefied in the condenser ill by surrounding cooler air which flows over the surfaces of the coil and fins, and the liquefied ammonia flows through a conduit l9 into a conduit 20 communicating 5 with one end of the evaporator or cooling element II], the conduit l9 being U-shaped at 2| to provide a liquid seal.

The cooling element l0 may comprise a coil (not shown) arranged within a shell 22 provided with trays 23 for freezing water. An inert gas, such as hydrogen, flows from a conduit 24 and enters the end of the cooling element opposite to that into which liquid ammonia is admitted. The hydrogen and liquid ammonia are in counterflow, therefore, and the ammonia evaporates and diffuses into the hydrogen with consequent absorption of heat from the surroundings of the cooling element in the storage compartment l2. The resulting gas mixture of ammonia and hydrogen, that is, gas strong in ammonia, fiows from the cooling element I!) through conduit 20 which communicates at its lower end into the lower end of an absorber 25 comprisingan enclosed vessel provided with a coil 26 through 25 which a suitable cooling medium, such as water, may be circulated.

The ammonia is absorbed out of the strong gas mixture into weak absorption liquid which enters. the upper part of the absorber through a verti- 80 cally extending conduit 21. The absorber may be provided with a plurality of distributing plates or bafiles (not shown) to insure the absorption of ammonia into the weak absorption liquid, and

the hydrogen, which is practically insoluble and weak in ammonia, passes upwardly from the absorber 25 through conduit 24 into the cooling element Ill. The conduits 20 and 24 are preferably in thermal contact or heat exchange relation, as diagrammatically shown in Fig. 1, so that heat is transferred from weak gas entering the cooling element through conduit 24 to the strong gas leaving the cooling element through conduit 20. The absorption liquid flowing downward through the absorber 25 in counter-fiowto the gas mixture becomes enriched in ammonia and passes through conduit 28 and an inner conduit 29 of a liquid heat exchanger 30 to a coil 3| disposed about the lower end of flue IS. The strong absorption liquid is heated in the coil 3| by the main gas burner I5 and is raised by thermo-syphon action from the coil through conduit 32 into the upper part of the generator [4. The absorption liquid is raised to a higher level in the generator l4 than it is in the absorber 25, and

absorption liquid weak in ammonia flows from the lower end of the generator through a conduit 33, outer conduit 34 of the liquid heat exchanger 30 and vertical conduit 21 into the upper end of the absorber 25. Refrigeration apparatus of the above type is generally described in Patent No. 1,609,334 to B. G. von Platen and C. 'G. Munters.

The heating means for the enclosed space I2 comprises an auxiliary burner 35 which is at right angles to the burner I5. The flame 35' of the burner 35 projects into the conical shaped lower end 36 of a flue 31 which extends vertically upward through the refrigerator cabinet I3 and constitutes the heater II to which are secured a plurality of heat dissipating elements or fins 38. The upper end of the flue 31 may be enlarged and provided with a plurality of baflles 39 which may be so regulated that they prohibit the downward flow of air surrounding the cabinet and are automatically opened thermostatically in a suitable manner in response to the temperature of hot gases rising in the flue 31. Similar baffles maybe arranged at the lower end of the flue 37 if it should be desirable in certain instances to prohibit the flow of air into the lower end of the flue when the burner 35 is not being operated to heat the enclosed space I2.

During normal operation of the above-described refrigeration apparatus, heat must be applied to the generator I4 and its contents at or above a predetermined rate by the main burner I5 in order to heat the refrigerant to its vaporization temperature or boiling point so thatrefrigerant will be vaporized and expelled out of solution from the absorption liquid. When the enclosed space l2 tends to fall below the desired temperature and heat is no longer applied" to the generator, the generator and its contents are cooled by the surroundings. Subsequently, when the enclosed space tends to rise above the desired temperature and the operation of the refrigeration apparatus is again initiated, heat must be applied to the generator I4 and its contents by the main burner I5 for a relatively long period of time before refrigerant is heated to its vaporization temperature and expelled out of solution from the absorption liquid.

In accordance with my invention, in order to reduce the time that effective cooling is obtained after operation of the refrigeration apparatus is initiated, the main burner I 5 and auxiliary burner 35 are so arranged and controlled that, during a heating period of the enclosed space I2, the application of heat to the generator is not discontinued but modified to apply heat to the generator at such a rate that heat of liquid is supplied to the refrigerant to heat the refrigerant to a temperature slightly below its vaporization temperature. In this manner, when a heating period is terminated and the operation of the refrigeration apparatus is again initiated, the refrigerant is heated to its vaporization temperature in a relatively short time and the cooling element In is effective substantially immediately to maintain the enclosed space at the desired temperature.

This may be accomplished by conducting a suitable combustible gaseous fuel from a-source of supply (not shown) through a. conduit 40 to an adjustable pressure regulating valve M which reduces and maintains substantially constant the pressure of the gas supplied to the gas burners I5 and 35. From the pressure regulating valve 4| gas flows throughconduit 42 to the main burner I5, and through parallel conduits 43 and 44, casing 45 and conduit 46 to the auxiliary burner 35. Within the casing 45 is arranged a valve 41 which is connected to an expansible bellows 48. The expansible bellows 48, tube 49 5 and thermal element 50 in the enclosed space I2 contain a volatile fluid and constitute an expansible fluid thermostat for closing and opening the valve 41 with an increase and decrease in temperature, respectively, of the enclosed space 10 I2. The operation of the apparatus just described is substantially as follows: v When the enclosed space I2 tends to riseabove the desired temperature the expansible fluid thermostat causes the bellows 48 to expand and close the valve 41. With the valve 4! closed only a small quantity of gas flows through conduit 43, the left-hand chamber of the casing 45 and conduit 46to the burner 35. This small quantity 20 of gas is delivered to the burner 35 to provide a pilot or ignition flame for the burners when the burner 35 is not being employed for heating the flue 31. With the valve 4! closed, the greater portion of gas flows through conduit 42 to the main burner I5, and the main flame I5 applies heat to the generator I4 at or above a predetermined rate which is effective to heat the refrigerant to its vaporization temperature or boiling point and expel refrigerant out of solution from the absorption liquid. After the operation of the refrigeration apparatus has thus been initiated the cooling element In effectively acts to cool the enclosed space when cooling is necessary to maintain the enclosed space I2 at the desired temperature. When the enclosed space I2 tends to fall below the desired temperature the expansible fluid thermostat causes the expansible bellows 48 to contract and open the valve 41, thereby varying the proportion of fuel delivered to burners I5 and 35. Thiswill permit gas to flow through the conduit 44 as well as through the conduit 43 to the burner 35, and the flame 35' becomes larger so that it will project into and heat the flue 31 when heating is necessary to 45 maintain the enclosed space I 2 atthe desired temperature. When the auxiliary flame 35 increases in size the main flame I5 becomes smaller, due to the fact that the pressure regulating valve 4| maintains the pressure of the gas delivered to the burners I5 and 35 substantially constant. The conduits 42, 43 and 44 are so dimensioned that, when the auxiliary burner 35 is being operated to heat the flue 31, the size of the main flame I5 is such that heat will be supplied to the generator I4 below the predetermined rate to heat the refrigerant toa temperature slightly below its vaporization temperature. When the operation of the refrigeration apparatus is again initiated to cool the enclosed space I2, the length 0 of time required to bring the refrigerant to its vaporization temperature will be relatively small.

In Fig. 2 I have shown a modification of parts of the apparatus illustrated in Fig. 1 for controlling the delivery of gas to the burners I5 and 5 35. The valve 5| shown in Fig. 2 may be employed'as a pressure reducing valve and interposed between the conduits 42 and 46 of the burners I5 and 35, respectively, and the main gas delivery conduit 40. The valve 5I comprises 70 a valve body 52 provided with a double conicalshaped chamber 53 which is cylindrical in any section, the upper and lower surfaces 54 of which are truncated. From the diametrically opposite sides of thecylindrical chamber 53 extend two due to the heating thereof while the enclosed passages 55 and 56 which communicate with conduits 42 and 46, respectively. The main gas delivery conduit 40 is connected to the valve body 52 and communicates With the chamber 53 at the lower truncated surface thereof.

Within the chamber 53 is arranged a cylindrical body 51 which is in the form of a double truncated cone, the flat cylindrical surfaces 58 of which are somewhat smaller in diameter than the corresponding truncated surfaces 54 of the chamber 53 in order to permit slight horizontal movement of the body 51 within the chamber 53. The conical-shaped surfaces of the body 51 are ground so that they will fit accurately against the conical-shaped walls of the chamber 53 when the body 51, which is connected by a rod 59 to the expansible bellows 48 of the expansible fluid thermostat, is moved either to the left or right in response to the temperature of the enclosed space to regulate the manner in which gases are delivered through the passages 55 and 56 to the burners l and 35, respectively.

The body 51 is provided with two small vertical passages Eli and BI which communicate at their lower ends with the main gas conduit 40. The passage 6!] has a right angle bend and the horizontal portion thereof is arranged to communicate with the passage 55 irrespective of the position of the body 51 in the chamber 53. The upper end of the passage 6| communicates with a horizontal passage 62 which extends to diametrically opposite points in the upper conical surface of the body 51. Gas will flow from the passage 52 either into the passage 55 or the passage 55, depending upon the position of the body 51 within the chamber 53. With the body 51 in its extreme left-hand position, as shown in Fig. 2, the passage 62 is closed to supply gas through the passage 56 and conduit 46 to the burner 35, and both the passages 60 and 62 are open to deliver gas through the passage 55 and conduit 42 to the main burner 15. The passages in the valve 5| are so dimensioned that, under these conditions, the main flame 15' will supply heat at or above the predetermined rate which will heat the refrigerant to its vaporization temperature or boiling point and expel the refrigerant out of solution from the absorption liquid.

When the enclosed space tends to fall below the desired temperature, the expansible fluid thermostat will cause the expansible bellows 48 to contract and move the body 51 in the direction of the arrow to the opposite side of the chamber '53. In this new position of the body 51 the passage 62 is closed to supply gas through the passage 55 and conduit 42 to the main burner 15, and is opento deliver gas through the passage 56 and conduit 46 to the auxiliary burner 35. The burner 35 will thus be effective to heat the flue 31 and maintain the enclosed space I2 at the desired temperature. Although the delivery of gas to the passage 55 is blocked 01f at the passage 62, gas is still delivered through the passage 60, passage 55, and conduit 42 to the main burner I5. The size of the main flame I5 is therefore decreased during the heating of the enclosed space I2 and effective to supply heat to the generator at such a rate that the refrigerant is heated to a temperature slightly below its vaporization temperature. When the body 51 is subsequently moved to the position shown in Fig. 2, the main flame l5 will again be increased in size and ef fective to bring the refrigerant to its vaporization temperature in a relatively short period of time space was being heated.

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

What is claimed is:

1. Apparatus for heating and cooling a space comprising a refrigeration system including a heat receiving part and a cooling element, means including said cooling element for cooling the space when said heat receiving part is heated at or above a predetermined rate, means including a heater for heating said heat receiving part and the space, and means for rendering said heater operative to heat said heat receiving part at or above the predetermined rate when it is desired to effect cooling of the space, and for rendering said heater operative to effect heating of the space when it is desired to heat the latter, said last-mentioned means rendering said heater operative to heat said heat receiving part belowthe predetermined rate while the space is being heated so that, when said heater is again rendered operative to heat said heat receiving part at or above the predetermined rate, the length of time required to effect cooling will be reduced.

2. Apparatus for'heating and cooling a space comprising an absorption refrigeration system including a generator and a cooling element, means including said cooling element for cooling the space when said generator is heated at or above a predetermined rate, means including gas burners for heating the space and said generator, means including a valve and conduits connecting said valve and said burners for delivering a combustible fuel to said burners, said valve controlling the quantity of fuel supplied to said burners, and means for rendering said valve operative to supply fuel to said generator burner to heat said generator at or above the predetermined rate when it is desired to effect cooling of the space, and for rendering said valve operative to supply fuel to the other of said burners to effect heating of the space when it is desired to heat the latter, said-valve and said conduits being so constructed and arranged that fuel is supplied to said generator burner to heat said generator below the "predetermined rate while the space is being heated so that, when said generator is again heated at or above the predetermined rate, the length of time required to effect cooling will be reduced.

3. Apparatus for heating and cooling a space comprising an absorption refrigeration system including a generator and a cooling element, means including said cooling element for cooling the space when said generator is heated at or above a predetermined rate, means including two fuel burners for heating said generator and the space, respectively, and means for rendering one of said burners operative to heat said generator at or above the predetermined rate when it is desired to effect cooling of the space, and for rendering the other of said burners operative to effect heating of the space when it is desired to heat the latter, said last-mentioned means rendering said generator burner operative to heat said generator below the predetermined rate while the space is being heated so that, when said generator burner is again rendered operative to heat said generator at or above the predetermined rate, the length of time required to effect cooling will be reduced.

4. Apparatus for heating and cooling 2. space comprising an absorption refrigeration system including a generator and a cooling element, means including said cooling element for cooling the space when said generator is heated at or above a predetermined rate, means including burners for heating the space and said generator, means including a'valve and conduits connecting said valve and said burners for delivering a combustible fuel to said burners, said valve controlcomprising an absorption refrigeration system ling the proportion of fuel supplied to each of said burners, and means for rendering said valve operative to supply fuel to said generator burner to heat said generator at or above the predetermined rate when it is desired to effect cooling of the space, and for rendering said valve operative to supply fuel to the other. of said burners to effect heating of the space when it is desired to heat the latter. 5. Apparatus for heating and cooling a' space comprising an absorption refrigeration system including a generator and a cooling element, means including said cooling element for cooling the space when said generatoris heated at or above'a, predetermined rate, a heating flue in heat transfer relation 'with the space, means including burners for heating said generator and said flue, and means for rendering one of said burners operative to heat said generator at or above the predetermined rate when it is desired to effect cooling of the space, and for rendering the other of said burners operative to heat said flue when it is desired to effect heating of the space.

6. Apparatus for heating and cooling a space comprising an absorption refrigeration system ineluding a generator and a cooling element, means including said cooling element for cooling the space when said generator is heated at or above a predetermined rate, means including gas burners for heating said generator and the space,

respectively, means including a valve and conduits connecting said valve and said burners for K delivering a combustible fuel to said burners,

said valve controlling the quantity of fuel'supplied to said burners, and means for rendering said valve operative to supply fuelto said generator burner to heat said generator at or above the predetermined rate when it is desired to effect cooling of the space, and for rendering said valve operative to supply fuel to the other of said burners to effect heating of the space when it is desired to heat the latter, said valve and said conduits being so constructed and arranged that fuel is supplied to said generator burner to heat said generator below, the predetermined rate while the space is. being heated and that fuel is supplied to said other burner to maintain a pilot flame while said generator is being heated.

7. Apparatus for heating and cooling a space including a generator and a cooling element,

means including said cooling element for cooling the space, means including burners arranged to heat said generator and the space, respectively,

- means including a valve and conduits connecting said valve and said burners for delivering a combustible fuel to said burners, said valve controlling the proportion of fuel supplied to each of said burners, said valve being operative to permit fuel to be supplied to said generator burner to heat said generator .when it is desired to effect cooling of the space, and also operative to. permit fuel to be supplied to the other of said burners when it is desired to effect heating of the space,

and said valve and said conduits being so constructed and arranged that fuel is always supplied to one of said burners to maintain an ignition flame.

8. Apparatus forheating and cooling a space comprising refrigeration apparatus including a heat receiving part having a flue and a cooling element in heat transfer relation with said space,

a heating flue in heat transfer relation with said space, a common source of combustion gases for said flues, and means to vary the proportion of gases flowing in said flues.

9. Apparatus for heating and cooling a space as defined in claim 8, in which said means to vary the proportion of gases flowing in said flues is automatically responsive to temperature.

10. Apparatus for heating and cooling a space comprising a refrigeration system including a heat-receiving part and a cooling element arranged to cool said space, a source of heated fluid, means -to,fiow heated fluid from said source in thermal contact with said heat receiving part,

' means to flow heated fluid from said source in heat transfer relation with said space to be space, said last-mentioned means being constructed and arranged to permit continuous flow of heated fluid to said heat receiving part and intermittent flow to said space.

11. Apparatus for heating and cooling a space comprising a refrigeration system operated by heat and having a cooling element to cool said space, means including a single heater arranged to heat said system to produce cooling of said space and also arranged to heat said space, and means to vary the quantity of heat from said heater which is utilized to heat said system and said space, respectively, to control the temperature of said space, said last-mentioned means being constructed and arranged to permit continuous heating of said system and intermittent heating of said space.

GUNNAR GRUBB.

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