US2182318A - Refrigerating apparatus - Google Patents

Description

Dec. 5 1939. E. B. NEWILL REFRIGERATING APPARATUS 2 Sheets-Sheet 1 Filed Nov. l, 1935 .y' w /W W ATTORNEYS Patented Dec. 5,1939

UNITED STATES REFRIGERATING APPARATUS Edward B. Newill, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application November 1, 1935, Serial No. 47,861

9 Claims.

This invention relates to refrigerating apparatus and more particularly to multiple refrigerating systems having a liquefying apparatus of small capacity having control means for individually controlling the supply of refrigerant to sections of the multiple system.

In refrigerating systems it is normally necessary in order to insure satisfactory refrigeration, to build the system sufficiently large and having sufficient capacity to take care of the heaviest possible load. Thus, in air conditioning, where the load is greatest during the middle of the afternoon, it is necessary to design this system with a sufficient capacity to take care of this peak load. From this it is evident that at other times of the day the system operates at considerably less than full load. If some means were provided for making use of this excess capacity in other parts of the day and storing it 20 for use during the peak load capacity, the capacity of the system required to be installed could be considerably reduced.

The peak load condition, however, is not confined merely to air conditioning, but is present in nearly all refrigerating requirements, and in fact is not limited to refrigeration at all but in practically all situations where power is required.

It is possible to increase the hold-over capacity of the evaporator by surrounding it with a congealing solution or a brine which during periods of heavy loads gives up refrigeration upon the rising temperatures. However, it has been found objectionable to surround the evaporating means used for normal refrigeration, with brine or a congealing solution because of its bulk and cumbersomeness and because it reduces the heat transfer emciency of the evaporating means.

It is therefore an object of my invention to provide a refrigerating system of. limited capacity wherein a proper and adequate supply of refrigeration to a primary evaporating means is insured, and wherein the excess capacity of the system under light loads may be stored and made use of during peak loads.

It is a further object of my invention to provide a multiple refrigerating system wherein one evaporating means or a section of the evaporating means is given preference while a second evaporating means receives refrigeration as required after the refrigerating requirements of the preferred evaporator are taken care (if.

it is a further object of my invention to provide a multiple refrigerating system having a refrigerant liquefying means of relatively small capacity which is provided with a control means for giving preference in the circulation and evaporation of refrigerant to certain sections of the evaporating means in a predetermined order.

Further objects and advantages of'the present invention will be apparent from the following 5 description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a diagrammatic representation of a multiple refrigerating system embodying my invention; and

Fig. 2 is a diagrammatic representation of a multiple refrigerating system containing three evaporators embodying my invention. 15

Briefly, in my refrigerating system, I provide a relatively small compressor and condensing means connected in a closed circuit with a plurality of separate evaporators arranged in parallel refrigerant circuit relation, each of which are provided with a separate expansion valve at the inlet and a separate solenoid valve at the outlet, which opens when energized. A thermostat switch means is provided for each evaporator, the first of which insures that the preferred evaporator will be operatively connected to a compressor whenever it requires refrigeration. When the preferred evaporator does not require refrigeration, this same. thermostatic means makes it possible for the second preferred evaporating means to obtain refrigeration. This second preferred evaporating means is likewise provided with a temperature responsive means which causes it to be operatively connected to the compressor and condensing means when the first preferred evaporator does not require refrigeration and when this second preferred evaporating means does require refrigeration. If desired, a third evaporator may be provided which will be able to receive refrigeration only when refrigeration is not required by a first and second preferred evaporator.

Referring now to the drawings, there is shown a compressor 20 driven by an electric motor 22 for compressing therefrigerant and for forwarding thecompressed refrigerant to a condenser 24 where the refrigerant is liquefied and cooled in a receiver 26. From the receiver 26, the refrigerant is forwarded to a supply conduit 28 which extends to an expansion valve 30 located within an insulated enclosure '32. This expansionvalve 80' in turn is connected to an evaporating means 34 also located within the insulated enclosure 32. At the outlet of the evaporating means 34 isan electric solenoid valve 36 which opens when ener e gized 't'd'permit'the flow of refrigerant from the evaporating means 34,into the return line 38 which returns the evaporated refrigerant back to the compressor.

From the supply conduit 28 a branch conduit 46 extends to an expansion valve 42 located within an insulated enclosure 44 which contains an evaporating means 46 connected to the expansion valve 42.. At the outlet of the .evaporating means 46 theref is provided an electric solenoid 'valve 48 similar to the valve 36 which opens when energized to permitthe flow of evapusing a relatively small motor compressor condenser unit which is only of sufiicient capacity to take care of the refrigerant requirements of one of the evaporating means 34 or 46 at a time.

There are any number of refrigerating situations where such a system might be used to advantage. As one example, the evaporating means 34 may be used in normal direct refrigerating relationship with some medium to be cooled such as air or a liquid wherein peak load conditions occur at intervals. In such an example, the second evaporating means would be used during light load conditions to cool a brine, or a congealing solution which should be arranged in such a way that it would supply refrigeration to the medium cooled .by the preferred evaporator 34, under peak load conditions so as to reduce the amount of refrigeration required under peak load conditions from the evaporator 34 to maintain the desired refrigerating conditions. Thus the refrigeration capacity of the system during light load conditions would be used to reduce the refrigerating requirements of both the compressor condenser means and the preferred evaporator during peak load conditions so that these portions of the system could be made of a considerable lesser capacity than the peak load to be encountered. Another example of the use of such a system would. be to use the preferred evaporator 34 to maintain foodstuffs such as ice cream at a proper temperature, while a second evaporator 46 might be used for less rigid refrigerating requirements such as to cool water for drinking purposes or even for cooling or air conditioning the store.

My invention contemplates the provision of an automatic control to properly control the application of refrigerant to the evaporators in such a system. In order to do this I provide two thermostatic control switches shown diagrammatically, of an unusual nature. The first of these switches is provided with a thermostat bulb 56 located within the medium in the insulated enclosure 32 containing the evaporating means 34. This thermostat bulb 56 is connected to a bellows 52 which operates a flexible spring arm 54 of spring material which carries the contacts 56 and 58. A horse shoe permanent magnet is provided which cooperates with the flexible spring .arm 54 to provide a snap action thereof.

When refrigerationis required by the medium within the enclosure 32 the volatile fluid in the thermostat bulb 56 expands causing the bellows 52 to expand and move the flexible switch arm 54 upwardly to placethe contact 56 into engagement with the contact 62 which permits the flow of electric energy through the electric conductor 64, through the contacts 56 and 62 and through the electric conductor 66 to the solenoid valve 36 to open the'solenoid valve 36 and thence through the electric conductor 68 back to the electric conductor 16 which connects to'the opposite terminal of the electric supply. At the same time the contact 58 makes contact with a contact 12 which permits the flow of electric energy from the electric conductor 64 to the contacts 12 and 58 and the electric conductor 14 to the compressor motor 22 which connects to the opposite electric terminal.

Thus through the making of these contacts the solenoid valve 36 is opened and the motor compressor unit begins its'operation. Liquid refrigerant is supplied to the evaporating means under the control of the expansion valve 36 and the evaporated refrigerant is withdrawn from the evaporating means in the normal manner by the by a thermostat, bulb 86. This thermostat bulb 86 is located within the medium enclosed in the insulated enclosure 44 which is cooled by the evaporating means 46. This thermostat bulb 86 is operatively connected to a bellows 82 which operates a flexible switch arm 84 of spring material provided with a contact 86 for engaging the contact l9 and a second contact 88 for engaging a contact 96 which is connected by an electric con ductor 92 to electric conductor 64. A horse shoe permanent magnet I66 is provided for cooperating with the spring arm 84 to provide a snap action for preventing arcing at the contacts.

When the temperature of the thermostat bulb 86 is high the contacts 19 and 86 close to permit the flow of electric energy through the electric conductor 94 to the solenoid valve 48 to open the solenoid valve 48 providing the contacts 56 and 16 closed. The solenoid valve 48 is also connected by the electric conductor 96 to the electric conductor 16. At the same time the closing of the contacts 86 and 96 permits the flow of electric energy from the electric conductor 64 through the conductor 92 and the conductor 14 to the compressor 22 to cause the compressor unit to operate and to supply refrigeration to the evaporating means 46 provided refrigeration is not required by the evaporating means 34.

Thus in this system, the preferred evaporating means 34 always maintains the proper temperature within the insulated enclosure 32 as measured by the thermostat bulb 56 while the medium within the insulated enclosure 44 can receive refrigeration if required, provided refrigeration is not requiredby the preferred evaporating means 34. The second insulated enclosure is fully pro- I valves I34, I35 and I31.

pressed refrigerant is liquefied and collected in a receiver I26. The liquid refrigerant is forwarded from the receiver through the supply line I28 and branch supply lines I30 and I32 to expansion The expansion valve I34 is connected to an evaporating means I36 enclosed within an insulated compartment I38 containing a medium to be cooled. The evaporating means I 36 is provided with an electric solenoid valve I40, normally closed, which expands when energized.

Similarly the expansion valve I35 is connected to an evaporating means I 42 enclosed within an insulated compartment I44 containing a medium to be cooled while the expansion valve I31 is connected to an evaporating means I43 enclosed within an insulated compartment I46 containing a medium to be cooled. The outlet of the evaporating means I42 is provided with an electric solenoid valve I48 normally closed, but which opens when energized and the outlet of the evaporating means I43 is provided with a similar solenoid valve I50. These electric solenoid valves I40, I48, I50 are connected to the return conduit I52 which conects to the intake of the compressor I20.

The evaporating means I36 and I42 are each provided with a thermostat control switch which is similar to that operated by the thermostat bulb 50, while the evaporating means I43 is provided with a thermostat control which is similar to that operated by the thermostat bulb 80. .In Fig. 2 the electric conductors connected to the opposite sides of the power line are designated by the reference characters I54 and I56. Located within the medium to be cooled in the insulated enclosure I38 is a thermostat bulb I which operates a bellows I62 operably connected to a flexible switch arm I64 formed of a spring material provided with a contact I66 connected to the electric conductor I54 and a second contact I68.

When the bulb I60 is at a comparatively high I temperature, the contact I66 makes contact with a contact I10 to connect the electric conductor I54 with the electric conductor I12 which connects with the electric solenoid valve I40 which in turn is connected by the electric conductor I 14 to the electric conductor I56. At the same time the contact I68 makes contact with a cooperating contact I16 which connects electric conductor I54 with an electric conductor I18, which in turn connects to an electric conductor I connected to the compressor driving motor I22 which is also connected to the conductor I56.

Thus, under these conditions the compressor driving motor isenergized to operate the motor compressor unit and the electric solenoid valve I40 is energized to open the outlet of the evaporating means I36 to cause refrigeration to be supplied to the evaporating means I38 to cool the medium contained within the enclosure I38. At the same time the electric solenoid valves I48 and I50 remain in a closed condition since they must receive their electric energy through a contact I82 which connects to an electric conductor I84. This contact I82 is engaged by the contact I66 to connect it to the conductor I 54 only when the thermostat bulb I60 is at a low temperature and when the switch arm I64 is in its lower position indicating that no refrigeration is required by the medium within the enclosure I38. Fig. 2 shows the switch arm I64in its lower or low temperature position.

Within the medium in the enclosure I44 is a thermostat bulb I86 connected to a. bellows I88 which operates a flexible switch arm I90 provided with a contact I92 connected to an electric conductor I84 and a second contact I94 connected to the electric conductor I18. When refrigeration is required by the medium within the enclosure I44, the thermostat bulb I86 is at a relatively high temperature causing the bellows I88 to expand and to cause the contact I92 to engage the contact I96 and the contact I94 to engage the contact I98. Theclosing of the contacts I94 and I98 will close the circuit to the compressor driving motor I 22. Should contacts I92 and I 96 be closed, and the contacts I66 and I82 be closed, the circuit will be closed through the electric conductor 202 to the electric solenoid valve I48 which is connected by the conductor 204 to the conductor I56. Under such conditions the motor compressor unit will operate and be operatively connected only with the evaporating means I42.

When refrigeration is not required by the medium within theinsulated enclosure I44, the contact I 92 makes contact with a cooperating contact 206 connected by an electric conductor 208 to a contact 2 I0 forming a part of the switch operated by the thermostat bulb 2I2 located within the medium to be cooled within the insulated enclosure I46. This thermostat bulb 2 I2 operates a bellows 2 I4 connected to a flexible switch arm 2 I 8 provided with a contact 2I8 adapted to make contact with the contact 2I0 and provided with a second contact 220 adapted to make contact with the cooperating contact 222 for closing the circuit through the electric conductor 224 to the compressor motor I22 to cause the operation of the motor compressor unit. Thus when-refrigeration is required by the medium within-the enclosure I46 and the other evaporating units require no refrigeration, then only the evaporated means I43 is placed in operative connection with the motor compressor unit. Thus in this system the evaporating means I36, I42 and I43 receive refrigeration preference in that order, according to their refrigeration requirements.

Such a system may be used where it is absolutely necessary that one refrigerating requirement be fully satisfied at all times, another where the refrigerating requirements should be satisfied most of the time but which is not absolutely necessary at all times, and a third where refrigerating requirements are not altogether necessary, but desirable. For example, the first preferred evaporator might be used to cool ice cream, the second to cool drinking water, and the third to provide air conditioning for the store. The second and third evaporating means might be provided with some sort of hold over arrangement to take care of their requirements during any peak load of the first preferred evaporator.

it should be noted that each of the switch means, both in Fig. 1 and Fig. 2, are provided with a spring opposing the expansion of the bellows and a screw thread adjustment for varying the tension of the screw, which screw thread adjustment is provided with a finger manipulator. In Fig. 1, the spring and finger manipulator adjusting means of the upper switch is designated by the reference character 91, while the spring and screw thread adjustment for the lower switch which is operated by the thermostat 80 is provided with a reference character 99. In Fig. 2, the spring and screw thread adjustment for the switch operated by the thermostat I60 is given a reference character 225 while the spring and screw thread adjusting means for the switches operated by the thermostas I86 and 2 P2 are given I finger manipulator may be adjusted to maintain any desired temperature limits within their respective evaporating means which they control. Thus, each of the evaporators may operate at different temperatures and one may operate at temperatures above freezing and another at temperatures below freezing. This is of a consider-' able advantage in air conditioning work where, for example, the evaporator 34 of Fig. 1 would be used to cool the air in the room and would operate at temperatures considerably above freezing such as between 35 F. and 45 F., while the second evaporator 46 might operate at temperatures considerably below freezing such as between 15 F. and 25 F., in order to freeze a congealing solution which would be used as a hold' over to provide refrigeration for air conditioning during the peak loads of the day so as to reduce the peak load upon the refrigerating system.-

evaporating temperature for air conditioning while the second evaporator 46 might operate at temperatures most suitable for freezing a congealing solution.

Such a two-temperatures refrigerating system might also be used for other purposes such as one for preserving ice cream while the other might be used for cooling drinking water. In such a case the evaporator 34 which would be used for cooling the ice cream would operate at temperatures around 5 F., whereas the other evaporator 46 would operate probably at temperatures around 40 F.

- The system shown in Fig. 2 might operate its evaporators at three different temperatures by suitable adjustment of the finger manipulator provided in the adjusting means 225, 221 and 229. Thus the evaporator I36 might operate at temperatures'around 5 F. for preserving ice cream, the evaporating means I42- might operate at temperatures around 40 F. for cooling drinking water, while the evaporator I43 might operate at temperatures of 50 to 60 F. for cooling the syrup rail, or at temperatures suitable for air conditioning purposes for air conditioning a store. Thus, it will be appreciated that I have provided an extremely fiexibie system capable of a number of very desirable occupations.

While the form of embodiment of the invention as herein disclosed. constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Refrigerating apparatus including refrigerant liquefying means and refrigerant evaporating means, said evaporating means having a portion provided with a temperature responsive means for operatively connecting said portion to the liquefying means when refrigeration is required by said portion, said temperature responsive means also including means for simultaneously controlling the operative connection of a second portion of the evaporating means with the liquefying means, a second temperature responsive means for controlling the operative connection of said second portion of the evaporating 2. Refrigerating apparatus including refrig erant liquefying means and refrigerant evaporating means, said evaporating means having a portion provided with a temperature responsive means for operatively connecting said portion to the liquefying means when refrigeration is re-.

quired by said portion, said temperature responsive means also including means for simultaneously controlling the operative connection of a second portion of the evaporating means with the liquefying means, a second temperature responsive means for controlling the operative connection of said second portion of the evaporating means with the liquefying means, said first mentioned temperature responsive means also including means for simultaneously controlling the operative connection of a third portion of the evapcrating means with the liquefying means, and a third temperature responsive means for controlling the operative connection of said third portion with the liquefying means, said second temperature responsive means also having means'for controlling the operative connection of the third portion of the evaporating means with the liquefying means.

3. Refrigerating apparatus including a refrigerant liquefying means and a plurality of evaporating means connected in a closed refrigerant circuit, and temperature responsive means for insuring that the liquefying means is operatively connected to the outlet of only one of the evaporating means at a time, said temperature responsive means including individual means for closing the outlets of a plurality of evaporating means when no refrigeration is required by the said plurality of evaporating means.

4. Refrigerating apparatus including refrigerant liquefying means and a plurality of refrigerant.evaporating means connected in a closed refrigerant circuit, control means for individually controlling the circulation of refrigerant through three of said evaporating means, said control means including means for preventing the circulation through a second and athird of said three evaporating means when refrigerant circulates through a first of said three evaporating means.

5. Refrigerating erant liquefying means and a plurality of refrigerant evaporating means connected in a closed refrigerant circuit, control means'for individually controlling the circulation of refrigerant through three of said evaporating means, said tioned in the outlet conduit of each of said pluapparatus including refrigrality of evaporating means, and means in operative association with each of said fluid control means for controlling the opening and closing of each of said fluid control means, said means preventing at least one of said fluid control means from opening when the other of said fluid control means are in open position.

'7. Refrigerating apparatus including in combination a plurality of evaporating means operatively connected to a refrigerant liquefying means, fluid control means individually positioned in the outlet conduit of each of said plurality of evaporating means, and means in operative association with each of said fluid control means for controlling the opening and closing of each of said fluid control means, said means opening not more than one of said fluid control each of said plurality of evaporating means, and switch means in operative association with each of said fluid control means for controlling the opening and closing of each of said fluid control means, said switch means being provided with an electrical interconnection which prevents at least one of said fluid control means from opening when the other of said fluid control means are in open position. I

9. Refrigerating apparatus including in combination a plurality of evaporating means operatively connected to a refrigerant liquefying means, fluid control means individually positioned in the outlet conduit of each of said plurality of evaporating means, and means in operative association with each of said fluid control means for controlling the opening and closing of each of said fluid control means, said means preventing said individually positioned fluid control means from opening when no refrigeration is required by said plurality of evaporating means.

EDWARD B. NEWIIL.

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