US2062054A

US2062054A - Air conditioning apparatus

Info

Publication number: US2062054A
Application number: US18295A
Authority: US
Inventors: Huggins Leroy Gale
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1935-04-26
Filing date: 1935-04-26
Publication date: 1936-11-24
Anticipated expiration: 1953-11-24

Description

NOV. 24, 1936. I HUGGlNs 2,062,054

AIR CONDITIONING APPARATUS Filed April 26, 1935 24; fit g 16 250.

Li H INVENTOR h LEROY GA 1.5 Huaams 2 W 2.4-. 21,. ATTOR Y Y Patented n... 24 193 6 NT OFFICE AIR CONDITIONING 'mnna'rus Leroy Gale Huggins, Wilkinsburg, Pat, assignor to Westinghouse Electric & Manufacturing I Company, East Pitts of Pennsylvania burgh, Pa., a corporation Application April 26,1935, Serial No. 18,295

-My invention relates to air conditioning apparatus, more particularly to apparatus comprising a plurality of evaporators for cooling-a embodying my invention; and

stream of air, and it has for an object to provide improved apparatus. I

A further object is, in connection with an air conditioning system comprising a plurality of compressors or compressor-condenser units and a plurality of evaporators connected to each compressor, to equalize the loads on the com:

pressors and to cool the entire air stream at.

partial load.

A further object is to utilize standard developed apparatus. v

in series, and I connect each compressor to the firstevaporator in series in one group and to the second or subsequent evaporator in another. group. Thus, the higher load of the first ev'aporators, due to the higher temperature'of the incoming air, is distributed among a plurality of condensing units. I

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which: I

Fig. 1 is a diagrammatic view of apparatus Fig. 2 is a diagrammatic 'view of a secondtembodiment of my invention.

Referring to the drawing in detail, I'show an air conditioning chamber Ill, which is connected I to the enclosure to be air conditioned through a tan II and a duct l2. The fan ll eiiects circulation of the air to be cooled through the chamber ill, the flow being from left toright in the embodiment illustrated in Fig. 1. v The fan may be located at any suitable point in the air stream, and location at the outlet of the chamber l being but one example of a suitable location. Air to be treated is conveyed to the chamber through a duct l3 and may be either air withdrawn from the enclosure, outdoor air, or preferably a mixture of both, as is well known in the art.

The chamber i0 contains a plurality of refrigerating evaporators for cooling the air and may, of course, contain any other desired air treating elements. In the present embodiment, I show four evaporator-s, it to II, the evapor torsbeing arranged so that the air stream first es over the evaporators I4 and I5 in parallel for the first stage of air cooling,-'and the respective parallel portions then pass over the evaporators i6 and II, respectively, for the second stage of air cooling. In other words, the group of evapo- 5 rators i4 and I5 is in parallel with the group of evaporators i5 and I1 and the evaporatorsof eachgroup are in series with, each other with respect to air flow. vThe evaporators are preferably of the same capacity, for example, each 10 evaporator may be a standard developed evaporatorof 6-ton or 72,000 13. t, u.' per hour capacity, or any other desired size. They may be of the usual cross-finned coil type. or of any other suitable type known in the art.

In the present'embodiment, I provide two compressor-condenser unit's i8 and I! for withdrawing vaporized refrigerant from the evaporators and for supplying liquid refrigerant thereto. Each unit includes, a compressor 20, a motor 2| ,ior driving the same, a'condenser 22 and a liquid receiver 23." Each unit maybe of standard design, having a capacity, for example, of 12 tons or 144,000 B. t. u. 'per'hour, serving two of the above-mentioned evaporators. While I 25 have shown separate compressor condenser units, the invention is not so limited but may be ema ployed where only separate compressors are used. I Inasmuch as the air passing over the evaporaters i4 and i5 is at higher temperature than the partially cooled air passing over the evaporators l6 and II, the refrigerating load on the former will be greater than the load on the latter. As stated above, it is an object of the invention to impose equal loads on the compressors or the compressor condenser units, inorder to provide thebest performance with apparatus embodying standard developed elements, and also to cool the entire air stream at partial load. I accom- 40 plish this by connecting each compressor condenser unit to the first stage evaporator of one group and to a second stage evaporator of the other group. I j

Conduit means 24 connect the liquid receiver 23 of the unit it with the expansion valves ll of the evaporators I! and i0, and conduit means 2! connect the outlet ends of said evaporators with the suction of the compressor. Likewise, conduit means 2. connect the liquid receiver of the unit I! with expansion valves 25 of the evaporators H and I1 and conduit means'il connect the outlet ends of 'said' evaporators withtlie suction of the compressor. The expansion valves 7,

Y are preferably oi. the im knownas thermostatic. I

, expansion valves, which control the admission of -refrigerant in accordance'with the superheat of the vaporized refrigerant discharged from the evaporator, thereby serving to supply such quantity of refrigerant as canbe fully vaporized. Any

' other vsuitable form of pressure-reducing device or restrlctor may be used.

Thermostatic control mechanism is preferably provided for controlling operation of the compressors. This mechanism includes a thermostat T that is responsive to the temperature of the air in the enclosure, and may be positioned either in the enclosure or in the stream of air returning from the enclosure to the chamber In through the .duct IS. The thermostat 1! is provided with two

switches

28 and 28 for controlling circuits 3] and 32, respectively, which supply current to the motors .of the units I8 and I9, respectively. The thermostat and the switches are arranged so that the'switch 28 is first closed.

upon increase in temperature to a predetermined value at which it is desired to maintain the enclosure, and so that the switch 28 is closed upon further increase to a slightly higher predetermined value. The switches open in reverse order upon decrease to slightly lower respective predetermined temperatures. stood that only the novel features of control are Operation The operation of the above-described apparalllustrated and that any other control feature may be employed.

tus is as follows: The fan H eflects circulation of air throughthe evaporators I4 to l1 in the chamber In in the manner described above.

When the air cooling load of the enclosure is sufilciently high to require operation of both compressors, the temperature rises to a value causing the thermostat T to close both switches.

Ene'rgization of both circuits and operation of by the evaporators H and I1, successively. As

each unit serves one evaporator in in the first stage of air cooling and one evaporator in the second stage of air cooling, it will be apparent that the loads on the two units will be equal.

When the temperature decreases to the lower value indicating that operation of one compressor will supply sufilcient refrigeration, the switch 28 is opened by the thermostat T to shut down the unit l8. The unit 18 continues to operate to serve the evaporators l4 and H. In this case, both portions of the air stream are cooled, one by the evaporator l4 and the other by the evaporator I'I. Both evaporators are subject to the temperature of the incoming air and are subject to equal loads. However, the temperature is now lower than when operation of both units is .required, so that the total load on the two evapthe unit I9 to discontinue further cooling of the air. Upon subsequent increase in tempera- It is to beunder- One half.

ture, the thermostat first closes the switch is to effect operation of the unit l8, and upon further increase in temperature, it closes theswitch 28 to efiectoperation of the unit l8.

In Fig. 2, I show anembodiment of my invention in which a greater number of evaporators are required to supply the cooling load. Three groups of evaporators are arranged for cooling the air in three parallel portions, each group including two evaporators in series with respect to air fiow, as in Fig. 1. In this case, the conduit means Ha and 25a connectthe' unit l8 to a third evaporator 33 in the first stage of air cooling of a third parallel portion of the air stream, as well as to the evaporators l5 and I8. Conduit means 26a and 21a connect the unit N to a third evaporator 84 disposed in the second stage of air cooling, as well as the evaporators l4 and H. In this case, the loads on the compressor condenser units are only partially balanced; however, the difference in load is only one-third of that which would be obtained if all three first stage evaporators were connected to one unit and the second stage evaporators connected to the other unit. The difference in loads is reduced to a suificiently low value to be unobjectionable.

From the above description, it will be seen that I have provided an arrangement in which the evaporators are so arranged as to equalize or substantially balance the loads on the compressors or compressor condenser units to which they are connected, and so that all portions of air stream are cooled when only one unit is opcrating. This arrangement greatly facilitates is f the use of developed apparatus of standard capacity.

While I'have shown my invention in two forms,

it will be obvious to those skilled in the art that it is not so limited, butis susceptible of various other changes and modifications, without departing from the spirit thereof, and I deslre,-

therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the apended claims.

What I claim is: 1. In air cooling apparatus, the combination of a plurality of compressors, a plurality of evapoparallel portions of the air stream.

2. In air cooling apparatus, the combination of a" plurality of groups of evaporators, means for conveying air over said groups in parallel, the evaporators in each group being arranged to cool the air in successive stages, a plurality of conipressors, each compressor being connected to at least one evaporator in each stage of air cooling and in each parallel portion of the air stream.

3. In air cooling apparatus, the combination of a plurality of compressors including first and second compressors, a plurality of evaporators connected to each compressor, means for circulating air over said evaporators, said evaporators and the circulating means being arranged so that one portion of the air stream is first cooled by an evaporator of the first compressor and then by an evaporator of the second compressor and another parallel portion of thealr stream is first 55 connected to evaporator elements in a plurality of 1 cooled by an evaporator of said second compressor and then by an evaporator of a compressor other than the second compressor.

, 4. In air cooling apparatus, the combination of a plurality of evaporators, means for convey-- ing air oversaid evaporators, said evaporators being arranged in-a plurality of groups that are in parallel with respect to air flow, each group comprising a first and a second evaporator over which the air flows in the order named, and a plurality of compressors each connected to the first evaporator of at least one group and to the second evaporator of at least one other group.

5. In air cooling apparatus, the combination of a plurality of compressors, a first and a sec ond evaporator connected to each compressor, means for circulating air over said evaporators, said evaporators and the circulating means being arranged so thatair fiows over a first evaporator and then over a second evaporator and so that each first evaporator is in series with the second evaporator of another compressor and in parallel with the first evaporator of another compressor with respect to air flow.

6. In aircooling apparatus, the combination of a plurality of compressors, a plurality of evaporators connected to each compressor, means for circulating air over said evaporators, said evaporators and the circulating means being arranged so that each parallel portion of the air stream is cooled in successive stages by evaporators of a plurality of compressors and so that at least two evaporators of each compressor are in different air cooling stages.

7. In air cooling apparatus, the combination of a plurality of evaporators arranged in groups means for circulating air over the evaporators,

the several groups being arranged in parallel andthe evaporators in each group being arranged in series with respect to air fiow, a plurality of compressors for said evaporators, each compressor being connected to a plurality of evaporators disposed in different groups and in difierent positions in the order of air flow.

LEROY GALE'IIUGGINS.