US2602307A - Air-conditioning method and apparatus therefor - Google Patents

Description

July 3 1952 G. c. coLLlsoN 2,602,307

AIR-CONDITIONING METI'VIODl AND APPARATUS THEREFOR Filed oct. 31', 1949 f 5 sheets-sheet 1 eoqe Chester Colison ATTORNEY July 8, 1952 G. c. coLElsoN 2,602,307

AIR-CONDITIONING METHOD AND APPARATUS THEREFOR Filed oct. 51, 1949 s sheets-sheet 2 le A FIG. 2

HEAT EXCHANGER I4 as \34 Mm 43Bi 43 c \35 PERI VALVES DUCTS l5 uP FLow uowN Fuow F IG 3 0 X: No now INVENTOR Georqe Chesfer Colllson x A f T cLosED VALVE ATTORNEY O: OPEN VALVE l A Byuw Julyr 8, `1952 s sheen-sheet s INVENTOR. George Chesl'er ColIison BY A,

ATTORNEY Patented July 8, 1952 UNITED :sTATEs OFFICE AIR-CONDITIONING METHOD AND APPARATUS THEREFOR 11 Claims.

The object of the invention is to provide a method and means for treating the interior air of habitable structures, so that the temperature in the latter may be economically maintained at a degree comfortable to the occupants, or so treating air in other inclosures as to economically increase its heat contentvwhere heat is a consideration in the use of the inclosure;r to provide a method and means for the indicated purpose in which, when-heat. is desired, it may be obtained from subsurface earth, or at times from the outside air where, at moderate temperatures, it is inexhaustible; to provide a thermo-dynamic air heating apparatus having a high coeflicient of performance; to provide aV method and means for himidity control, and for changing the air with sufficient rapidity to constitute, not only ample ventilation, but effective air cleaning as well; to provide av method and means to cool the air when desired: and gellerally to provide an apparatus f cr'the purpose specified, which is...lconriposed of conventional parts, comparatively few in number, and which is therefore susceptible'of cheap manufacture; operation and maintenance.- c

With this object in View, the invention cone sists of a construction and combination .of parts, and a method of operation therefor, of which a preferred embodiment is illustrated in the accompanying drawings, in which:

Figure 1 is a diagrammatic View showing the assembly oi parts necessary to practice the invention;

Figure 2 is a similar View of the heat exchanger;

Figure 3 is a chart ci the valve movements (for one cycle) in the heat exchanger; also of the corresponding flows through the heat.- absorption ducts, for each of the twelve periods of valve operation.

Figure 4 is a diagrarnrnaticL view, similar to,

Figure 1. showing the assembly of parts necesisary for the inventionto function as a means for super-cooling. H

The apparatus employed for practicing the invention with. a high coeicient of `performance consists of the blower I Il and its smaller, but otherwise almost identical counterpart II, which latter functions, however, not strictly as a blower, but as a retarding turbine; a similar blower I2, and its similar counterpart, the turbine I3; a heatfexchanger- It; a tubular conductor l5, connecting the axial intake of blower I0 with the axial discharge of turbine Il.; a like conductor i6, connecting the per-initieraly discharge of blower I2 with the peripheral intake of turbine I3; and l means, such as the valve controlled pipe or conductor Il, for admitting a heat-carrying Inedium (water from sub-surface earth, for example) into the conductor system I5.

The two blowers and the two turbines, for purposes of clarity, are shown in the accompanying drawings as consisting merely of a single stage each. The turbines, except for the smaller cir-o.

cumference of the rotors, the direction in which the vanes or impellers are cupped,- and the peripheral intake and center exhaust are similarVV to the blowers. Preferably the-two blowers and the two turbines are actuated in synchronism. Toward that end, the impellers or vanes of 'each pair are mounted on a shaft I8 common to the two, the two shafts being axially aligned and coupled to that of the driving motor I9. i

In the embodiment shown, the blowers are of the center-,intake peripheral-discharge type, while the smaller turbines take in at the periphery and discharge at the center. The shaft and duct connections between each blower and its peripherally slower turbine are such that the.

the turbine that is cumulative rather than op-V posing; thus the turbine tends to return' to the shaft a modicum of the power consumed or absorbed by itscorresponding blower, and in consequence, the required demand on .motor I9 is, with due allowance for frictionalv and other losses, approximately the difference between the combined power rating of the two blowers and the combined power rating of the `two turbines, rather than the sum of those two quantities'. As the blower I0 and its turbine I I are connected, they produce a sub-atmospheric pressure in the duct I5 connecting them;vblower I2 andits turbine I3, as connected, produce a super-atmospheric pressure in the duct vI6 connecting them. The ducts 22 and 23 are, respectively, the ultimate intake and discharge of the system, and are exterior tothe equipped building. The ducts 20 and 2| are, respectively, the delivery outlet of the heated (or otherwise conditioned) air, and

the exhausting outlet for used or vitiated air. Both of these outlets terminate within the building, and ordinarily would be coupled directly to the conventional air conditioning system of ducts within the building.

The volumetric space within the conductor I5 (between its blower I and its turbine II) and the volumetric space within the conductor I6 are respectively referred to herein as the expansion and compression chambers by reason of the functions of their respective blower-turbine couples, and these two chambers are in heat transfer relation within the heat exchanger I4, as explained in detail hereinafter.

While sub-atmospheric air in the expansion chamber I may be heat treated from any available source, it is proposed, as a practical expedient, to do so from water drawn from subsurface earth and, as hereinbefore stated, this is admitted through the pipe or conductor I1, and preferably through the turbine II, the vanes of which break it up into small drops. After its heat is abstracted by the air, this water must be Withdrawn, wherefore the conductor I5, at a point adjacent its entry into the heat exchanger, is formed with a trap 24, from the lowest point of which a pipe conducts its Water content to the intake of a small motor-driven pump 26, the

discharge 21 of which is submerged in the contents of a vessel 28, with tis outlet below the level of the discharge 29 of the latter. By this means a Water-seal is provided to prevent the entrance of exterior air into the expansion chamber through the pump.

One of the functions of which the apparatus is susceptible calls for'the admission of moisture into the conductor I5, and such moisture is admitted through the valve-controlled pipe 30 which is connected to an appropriate water supply.

When used for air conditioning purposes, where reduced temperatures and/orhumidity are desired, as in summer time, no useful function can be performed by turbine I3, therefore it is shunted with the by-pass 32, this by-pass being provided with a valve or shut-olf damper 33 which, when opened, aiords passage of air around the turbine I3, thus voiding the effect (the compression within chamber I6) that it would otherwise produce. Thus the functions of the whole compression side of the apparatus would be reduced to that of merely maintaining its normal current of air. A similar though modied by-pass 3I is provided around turbine II. This by-pass, when its valve 33 is opened, substantially voids the sub-atmospheric pressure within the expansion chamber. However, in order that the chamber may still operate to treat the air with water, this by-pass is formed cross-sectionally smaller than the duct I5, which results in a slight resid-V ual sub-atmospheric pressuren in the expansionv chamber, even though the valve 33 of this bypass is fully open. The slight sub-atmospheric pressure within the expansion chamber facilitates the normal entry, through the turbine I I, of water from pipe I1 into the expansion chamber.

The heat exchanger which establishes the heat transfer relation between the conductors I5 and I6 consists (Fig. 2) of low pressure manifolds 34 and 35; the high pressure manifolds 36 and 31; the three heat- absorption ducts 38, 39 and 40; the headers 4I, constituting in pairs the terminals of the three heat-absorption ducts; the valves 42 and 43 controlling communication betweeny the several manifolds and the several headers.

The ducts 38, 39 and 40 enclose each a loose filler 44, preferably of metal wool, which absorbs heat from high pressure air passing through the ducts and gives it up to the low pressure air later passing therethrough.

As shown in Figure 1 of thedrawngs, the tubular conductor I5 is separated between the trap 24 and the blower I0, and the terminals thus provided are connected to the manifolds 34 and 35. Similarly, the manifolds 36 and 31 are included in the tubular conductor |16. Thus the two sides of the heat exchanger become elements of the expansion and compression chambers, the interior space of tthe conductors I5 and I6.

'I'he valves 42 and 43 may be specimens of any conventional valve adapted to intermittent opening and closing, and the present organization Acalls for the co-ordinated operation of the full opened before the rst set close. `This require-- ment applies also to the valves 43 and is necessary (rst) to avoid any interruption in the air currents fiowing in the low pressure manifolds 34-35 and high pressure manifolds 36-31, and (second) to avoid the intermingling of the high pressure and the low pressure currents. This prescribed co-ordinated valve movement may be accomplished by any of a number of available conventional means.

But while all the valves 42 and 43 as a set are coordinated, the corresponding valves for. each duct are synchronized, that is, they are simultaneously opened or closed.

The operation may be best understoodby reference to Figure 3 of the drawings showing one cycle of operations divided intotwelve periods. During the first period, with the valves 43A and 43D, 43B and 43E, and 42C and 42F open as shown, air in the low pressure chamber I5 will flow from the manifold 34, down through duct 40, into manifold 35, and air from the high pressure chamber I6 will flow from the manifold 36, up through ducts 38 and 39, into manifold 31. All the other valves being at this instant closed, low pressure air will be excluded from ducts 38 and 39, and high pressure air will be excluded from duct 40. But in the next period, valves 43A and 43D close, which changes the previously described air paths only to the extent of excluding high pressure air from duct 38. At the beginning of the third period, the valves 42A and 42D are opened, and low pressure air begins to flow from manifold 34, down through duct 38, in multiple with the ow of low pressure air downward through duct 40 (as above described). At the beginning of the fourth period, the downward flow of low pressure air through duct 40 is shut off by the closing of the valve pair 42C and 42F, and the ductremains inert during the remainder of this period, at the end of which it becomes a conductor for a reverseV flow (upward) of high pressure air, upon the opening of valve pair 43C and 43F.

It will be seen, by following the full cycle of operations charted in Figure 3, that each pair of valves is open duringl five periods in the cycle and closed during seven periods; that in every cycle, each duct is subjected to upflow of compressed air for a sequence of five periods andto downflow of expanded air for a sequence of ve periods, with the sequences overlapping in such wise that, during the changeover of one duct from upflow to downflow (or vice versa), there is no interruption to flow in either of the other two ducts. Moreover, at no time will any path be open to permit flow from the high pressure side of the apparatus to the low pressure side.

The heat exchange function is performed by the fillers 44 with which each duct is charged. These llers, presenting a comparatively extensive area to the high pressureair when the same traverses the ducts, absorb the-heat therefrom and conduct it to the low pressure air when the ducts are conductors, in counterow, for the latter.

While the heat exchangerand compression side of theapparatus are not indispensable to the successful practice of the invention, they do materially increase its eciency and raise its co-eiiicient of performance. The expansion side, however, is essential, and without more is susceptible of a highly useful function. By placing the intake 22 of turbine II within the inclosure to be heated, the expansion side of the apparatus, divested of the'heat exchanger and the compression side, constitutes in itself a complete heating system, adaptable also to summer cooling. Air to be heated, drawn normally from the colder parts of the building, enters expansion chamberr I5 through turbine II, where the air undergoes expension, due primarily to the exhausting action of blower I0, and secondarily to the retarding action of turbine I I. Coincident with its expansion, the current of air is subjected to intimate contact with water drawn from sub-surface earth or other available heat source, the water being .fed by pipe I1 directly into the intake side of turbine II, where it is dashed into small particles by the rotor of the turbine. Thus the expansion of the air will be nearly isothermal, or at least its temperature drop will be limited to practically the temperature of the copious supply of water fed from pipe l1. Therefore the yotherwise normal thermo-dynamic cooling of the air will be offsetv by .the heat abstracted from the water; When recompression takes place (that is, when the rareiied air in the expansion chamber is forced into the atmosphere against the superior pressure of the latter, and consequently-gains or regains that higher pressure) as when the air is discharged from outlet'I 20 into the equipped inclosure, such recompression will be accomplished adiabatically, with resultant thermo-dynamic heating. This continued process of (nearly) isothermal expansion and adiabatic re-compression results in the addition of substantial increments cf heat until the interior air is finally of the desired temperature. Moreover, it is possible to accomplish this result with but moderate air pressure diiierence. a differential that is within the practical range of rotary types of air-moving machinery.

As the water with which the air is initially7 saturated is dissipated therefrom, it accumulates,

as before explained, in the trap 24from which it is withdrawn by the pump 26 and discarded or returned to its original source.l Since the subatmospheric pressure in the chamber I5 must be maintained, the possibility of its loss through the pump 26 is insured against by the contents of the vessel 28 which is always available for pump priming purposes.

In the above mentioned apparatus consisting of the expansion side acting alone as an au' conditioning system, ventilation can be effected by 6` dividing inlet 22 into two multiple branches, one of which is extended outside the building. This branch should be valve or damper controlled, so as to regulate the proportion of outside air admitted into turbine Il.

In providing the compression side of the apparatus and establishing a heat exchange relation between it and the expansion side, the time for attaining the desired temperature in the treated air is materially reduced, as is also the Work of maintaining that temperature. A further advantage is, that with two pressure differentials (one for the expansion side and one for the compression side), their degree can be reduced to about one half of the pressure difference required for the expansion side working alone. These two lowered pressure differences are therefore as effective, in their sum, as the single greater pressure difference, and there is a consequent advantage due to the peculiar suitabilityvof rotary air-moving machinery to low pressure and high volume.

As air is discharged into the equipped building or inclosure from the blower I0, an approximately equal volume of air hitherto therein is removed therefrom by the blower I2, which it enters through the intake 2| and passes into the conductor (chamber) I6. But the turbine I3 tends to retard its discharge from the chamber, `and the result is compression of the air content of the chamber I6. butwith movement of the same air towards the turbine I3, and out through the. discharge 23. While under compression (and consequent thermo-dynamic heating), the air in chamber I6 is, as before explained, subjected to contact with the fillers 44, to'which it transfers its heat by conduction, and this heat is picked up in like manner by the expanded air in chamber I5, as a result of the operation of the heat exchange mechanism hereinbefore explained.

After having its heat abstracted while underl compression, the air in the compression chamber I6 passes on, and its impingernent on the rotor of turbine I3 effects a drop in pressure (re-expansion) to approximately atmospheric pressure, as the air is discharged through outlet 23, outside the building into the atmosphere.

It is obvious that the improved apparatus provides for a constant change of air in the equipped building, and that this is accomplished substantially without loss of heat, since the stale air, upon its passage through the compression chamber, has what heat it then contains (heat at temporarily augmented temperature due to the thermo-dynamic heating by compression) abstracted and transferred to expanded air which later undergoes further warming (by therrnc-dynamic heating) when it is re-compressed and ejected into the atmosphere within the building.

When exterior air is taken into the expansion chamber and is mixed with the finely divided water therein, its relative humidity approaches However, after the expanded air has absorbed heat in the heat exchanger, its relative humidity 'is materially reduced,v and upon recompression, as it is .discharged through outlet 20, the relative humidity is still further reduced. No lower relative humidity than that due to the second reduction would be desirable, hence any call forv humidity change would be an increase, which `may be accomplished by admitting moisture into chamber I5 in the form of spray entering the conductor I5 between the heat exchanger and the blower I0, and supplied through the valve-controlled pipe 3D.

While the invention, with all lparts function.- ing, is designed primarily for winter use, it is equally effective for cooling and humidity control in the summer time. It is to .provide for this latter function that by-,passes 3| vand 32 are incorporated. When the valve 33 of by-pass 3| is opened, turbine II is substantially shunted so that Vthe sub-atmospheric pressure in chamber I5 is correspondingly substantially voided, leaving only asmall residuum of reduced pressure, the purpose of which is to .facilitate entry vof water from pipe I'I, through turbine II into chamber I5. The relativelyv smaller cross sectional area of by-pass '3l exerts enough constrictive effect to produce the. slightly-lowerthan-atmospheric pressure in chamber I5. Operating thus at practically atmospheric pressure, conductor I5 therefore serves simply as a chamber in which the current of warm air is treated with water freshly drawn from sub-surface earth. 4The result of such treatment is, (1) the reduction of the sensible heat of the air so treated, and (2), if the dew point of the air is higher (as is often the case) than the temperature of the Water, the reduction of the humidity of that air.

When valve 33 of by-pass 32 is opened, turbine I3 is shunted so that` the otherwisesuper-atmospheric pressure in chamber IE is voided. Chamber I6 therefore acts only as a conductor through which air is moved by blower I2 in such Wise as to maintain its part of the desired system of circulation of air. This system of circulation comprises the following:

Outside air enters through intake 22, flows through chamber I5, where it undergoes water treatment; it is then expelled within the building, through discharge 20. Inside 'air enters intake 2I, flows through chamber IB'and is expelled outside the building through discharge 23.

For super-cooling',which is desirable in subtropical and tropical areas, but slight modification of the structure `of Figure 1 is necessary; but such modification is shown in Figure 4.

In the modication the air is untreated on the expansion side but water treated on the compression side which latter lconsists of the turbine and blower 616 whose peripheral intake and peripheral discharge respectively are connected by the conductor 6I which enters the heat exchanger 61, as in the form shown in [Figure 1. But adjacent the heat exchanger the conductor 6I' is provided `with a trap i62 from which extends a water discharge 63, controlled by a float Valve 65, Water being injected into the compression side through a valve control pipe 6-4.

The center discharge II of the turbine 'i5 is interior to the enclosure to be cooled while the center intake 68 to the blower 66 is exterior to the enclosure.

On the expansion side, the turbine I2 and blower 'I4 have their center discharge and center intake respectively connected by a conductor 'I3 which enters the heat exchanger `I'I, as in the form shown in Figure 1; but the peripheral intake to the turbine is interior to the enclosure while the peripheral discharge of the blower is exterior thereto.

In operation, inside air is drawn through theV intake 'III and turbine 'I2 into the conductor 13, the interior space of which functions as an expansion chamber. This air is ejected by the blower 'III through the discharge 69 and, just as in the structure of Figure 1, such air as is inthe chamber 'I3 is expanded. Under expansion,

thisl air is cooled thermo-dynamically and, passing throught he heat exchanger, it absorbs heat priorto discharge through the blower 'I4 Coincident to this operation, outside. -air enters through intake E8 and blower 66 into conductor (El, the interior space of which functions as a compression` chamber. Water being admitted through the supply pipe 64, the air in the compression chamber has its heat abstractedby such water. De-humidiiication ensues,l under appropriate conditions, even when the dwater is comparatively warm. The air is then lfurther cooled by heat exchange with the expandedairin expansion chamber 13, and passing to the turbine l5, is re-expanded to atmospheric pressure with consequent further cooling and is then discharged into the enclosure.. I

It is obvious that because of structural similarity of the two embodiments shown in Figures 1 and 4, both functions can easily be incorporated in a single apparatuswhich may be provided with conventional simple Vmeans to allow for alternate operation either for heating, or for super-cooling.

The invention having been described, what is claimed as new and useful is: v

l. A method 4for heating enclosures which comprises repeating in cycles the successive steps of rst expanding atmospheric air .in the presence of media yof high thermal capacity, then recompressing it to its original pressure and delivering it to the enclosure, then withdrawing it and compressing it to -superatmospheric pressure While in heat conductive relation to air undergoing the expansion step, and nally discharging it exteriorly ofthe enclosure.

2. A method for the temperature control of air'in habitable enclosures which comprises repeating in cycles thefsuccessive steps of first expanding atmosphericy air andy thenl reducing it toits original'pressure, and second, cornpressing it to super-atmospheric pressure while in heat-conductive relation to air undergoing expansion, and finally discharging it into the enclosure at atmospheric pressure after subjecting it toV one of said steps while discharging it from the enclosure after subjecting it to the other of said steps.

3. Apparatus for the purpose specied which comprises a conductor constituting an expansion chamber, a pair of synchronously driven air displacing units of different capacities connected to the remote ends of said conductor whereby air may be taken in through the smaller unit, expanded, and recompressed and discharged through the larger unit, meansfor admitting a' heat carrying agent of high thermal capacity into the conductor in the presence of the expanded air therein and consisting of a valve controlled water pipe leading from a water source ofv moderate heat content and discharging on the moving element yof the smaller unit for dashing into spray, and a Valve controlled by-pass shunting the smaller unit.

4.. Apparatus for the purpose indicated which comprises a pair of synchronously driven air displacing units of different capacities, a conductor so connectingthe same that airmay be taken thereinto through ythe smaller unit, vexpanded,. and recompressed and discharged through the larger unit, a second pair of synchonously driven air units of different capacities, a conductor so connecting the same that air may be drawn thereinto by the larger unit, compressed, and re-expanded and discharged through the smaller unit, a heat exchanger in heat conductive relation to both conductors, and means for admitting a heat carrying agent of high thermal capacity into the first said conductor in the presence of the expanded air.

5. Apparatus for the purpose indicated which comprises a pair of synchronously driven air displacing units of diiierent capacities, a conductor so connecting the same that air may be taken thereinto through the smaller unit, expanded, and recompressed and discharged through the larger unit, a second pair of synchronously driven air units of different capacities, a conductor so connecting the same that air may be drawn thereinto by the larger unit, compressed, and re-expanded and discharged through the smaller unit, a heat exchanger in heat conductive relation to both conductors, and a valve-controlled Water pipe leading from a water supply source of moderate heat content and discharging into the rst said conductor at the smaller unit connected thereto.

6. Apparatus for the purpose indicated which comprises a pair of synchronously driven air displacing units of different capacities, a conductor so connecting the same that air may be taken thereinto through the smaller unit, expanded, and recompressed and discharged through the larger unit, a Second pair of synchonously driven air units of different capacities, a conductor so connecting the same that air may be drawn thereinto by the larger unit, compressed, and re-expanded and discharged through the smaller unit, a heat exchanger in heat conductive relation to both conductors, and a valve-controlled water pipe leading 4from a Water supply source of moderate heat content and discharging into the first said conductor on the moving element of the smaller unit connected thereto.

7. Apparatus for the purpose indicated which comprises a pair of synchronously driven air displacing units of different capacities, a conductor so connecting the same that air may be taken thereinto through the smaller units, expanded, and re-compressed and discharged through the larger units, a second pair of synchronously driven air units of different capacities, a conductor so connecting the same that air may be drawn thereinto by the larger units, compressed, and re-expanded and discharged through the smaller units, a heat exchanger in heat conductive relation to both conductors, and means for admitting a heat carrying agent of high thermal capacity into the rst said conductor in the presence of the expanded air, and a valve-controlled by-pass shunting the smaller units of each pair.

8. A heat exchanger comprising a plurality of filler charged ducts, manifolds connected to the 6 remote ends of said ducts and designed for connection to uid carrying conductors Whose contents are at different heat levels, and co-ordinated valves controlling communication between the manifolds and the ducts, whereby the llers in the latter are alternately subjected to contact with the iiuids in the different conductors.

9. A method for the temperature control of air in habitable enclosures `which comprises repeating in cycles the successive steps of first compressing atmospheric air in the presence of media of high thermal capacity, then expanding it to its original pressure and delivering it to the enclosure, then withdrawing it and expanding it to sub-atmospheric pressure while in heat conductive relation to air undergoing the compression step and nally discharging it exteriorly of the enclosure.

l. Apparatus for the purpose indicated which comprises a pair of synchronously driven air vdisplacing units of different capacities, a conductor so connecting the same that air may be taken thereinto through the smaller unit, expanded and recompressed and discharged through the larger unit, a second pair of synchronously driven air displacing units of different capacities, a conductor so connecting the same that air may be drawn thereinto by the larger unit, compressed and re-expanded and discharged through the smaller unit, and a heat exchanger in heat conductive relation to both of said conductors.

l1. Apparatus for the purpose indicated which comprises a pair of synchronously driven air displacing units of diferent capacities, a conductor so connecting the same that air may be taken thereinto through the smaller unit, expanded and recompressed and discharged through the larger unit, a second pair of synchronously driven air displacing units of different capacities, a conductor so connecting the same that air may be drawn thereinto by the larger unit, compressed and re-expanded and discharged through the smaller unit, a heat exchanger in heat conductive relation to both of said conductors, and meansfor admitting a heat abstracting agent of high thermal capacity into the second said conductor in the presence of the compressed air therein.

GEORGE CHESTER COLLISON.

REFERENCES CTED The following references are of record in tle file of this patent:

UNITED STATES PATENTS Number Name Date 1,906,370 Darrow May 2, 1933 2,175,162 Waterll Oct. 3, 1939 2,175,163 Waterll Oct. 3, 1939 2,477,931 King Aug. 2, 1949

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