US2363944A - Air conditioning system control arrangement - Google Patents

Description

Nov. 28, 1944.

w. H. CARRIER AIR CONDITIONING SYSTEM CONTROL ARRANGEMENT Original Filed Aug. 12, 1939- 2 Sheets-Sheet 1 INVRNTOR. 91% xf-M O .Nov. 28, 1 944. w. H.- CARRIER 2,363,944

AIR CONDITIONING SYSTEM CONTROL ARRANGEMENT I Original Filed Aug. 12, 1939 2 Sheets-Sheei 2 g a 60 V 210 208 rsieseauw. 2a, 1944 h h ,V e 2,353,944 UNITED STATES ,PATE NT' OFFICE AIR CONDITIONING SYSTEM CONTROL ARRANGEMENT Willis Lama, Syracuse, N. .Y., assig'nor to Carrier Corporation, Syracuse, N. Y., a corporation of Delaware Original application August 12, 1939, Serial No. 289,740. Divided and this application July I,

1942, Serial No. 450,052

6 Claims. (Cl. 257-3) This invention relates air conditioning and is a division of application Serial No. 289,749 filed August 12, 1939.

The general object of the invention is to pro- .vide an arrangement including improved valve mechanism for use in an air conditioning system where fluid from a central source is routed to a pluralityof individual units serving dlflferent zones to be conditioned.

A feature of the invention resides in the provision of a valve mechanism in combination with a flow system for apportioning fluid between difierent circuits so that desired air conditions may be produced and maintained in difierent zones regardless of changes in load affecting said zones.

The valve mechanism and flow arrangement will be described in connection with a high pressure air conditioning system in which air is delivered at a relatively high static pressure of the order 01' five inches of water to a primary air main servin a plurality of units. Each unit is provided with a heat exchange device to which heating or cooling fluid may be routed as desired under control of applicant's valve mechanism and system of fluid flow control.

Secondary air, induced by the discharge of the primary air within each unit, flows through and in contact with, the surface of the heat exchanger therein, to be heated or cooled depending upon the character and amount of fluid I circulated through the heat exchanger.

Thus, a simple and efllcient system is provided wherein the primary air may be outside air in volume limited to the ventilation requirements of the conditioning areas, whereas the secondary air is heated or cooled to the proper degree, so that when mixed and discharged with the primary air a final volume will'be delivered as required to prbvide prescribed air conditions in a given area.

Fig. 1 diagrammatically illustrates a typical system embodying applicant's invention;

Fig. 2 is a diagrammatic view illustrating, in section, a valve adapted to modulate the cooling or heating action of local air conditioning units in response to changes in load requirements, and

diagrammatically illustrate the piping connecparatus of any desired type, and disposed at any desired point in or proximate a building to be conditioned. A fan 26 draws air through the casing, preferably from the outdoor atmosphere, whereby the air is conditioned in desired manner during its passage through the casing 25, and then discharges this air at relatively high static pressure into the primary high pressure air main 21.

The conditioner casing 25 preferably includes a filter 28, a, cooling coil 28 and a reheating coil 30. Cold" brine or other suitable conditioning medium is supplied to the coil 28 through supply line 3| and is withdrawn therefrom through return line 32 under the influence of pump 33 which returns the liquid'throughstrainer 34 to a cooler 35, of any desired type, from which the cooled refrigerant is returned to line 3|. Any desired meansmay be used to regulate suitably the temperature of the cooled refrigerant. Reheating coil 30 receives a heating medium, such as steam, from supply main "through branch line 31 under the control of valve 38'controlled by thermostat 39. The valve 33 admits steam to the coil 30 in a quantity sufllcient to maintain the temperature of the air leaving the casing 25 at a desired point, thus reducing the relative' humidity of the air leaving the cooling coil like 43 operative under winter operating conditions to increase the moisture content of air passing through the conditioner casing.

The pipes 44 and 45, respectively connected to pipes 32 and 3|, and respectively served by valves 46 and 41, may be used for connecting into the circuit of the cooling coil 29 a connection to a source of well water, ice-water storage tank, or a cooling tower or the like for use when the wet bulb temperature of the outdoor air is sufficiently low to permit the use of evaporative cooling instead of the refrigeration normally supplied in any desired manner to the cooler 35. It will be understood that when the valves 46 and 41 are opened, the valves 43 and 49, respectively located in lines 32 and 3|, will be closed.

Preferably a closed expansion tank. 5|! is connected by line 5| to the refrigerant return line 32, the closed expansion tank containing a quantity of compressible medium such as air and being employed at a low point in .the liquid cir-" culating system. It will be understood that if desired an open expansion tank may be used 60 at a high lever in the system in the same maning from the water return line 61.

The air delivered by the fan 26 to the primary air distributing main 21 is at a relatively high static pressure, of the order L5" of water. A

portion of this air is diverted from the primary main 21 and passes to a vertical riser 52 of zone A and a corresponding riser 52' of zone B Each vertical riser delivers air to a plurality of units designated generally as 53, through lateral connections 54. The primary air thus delivered to each unit serves to induce a relatively great circulation of secondary air and to promote desired circulation of air in the conditioned enclosures.

A pipe 55 connects with the cold water return line 32 and is adapted to deliver cold water or brine from said return line to cold water supply header 56, which, in turn, is adapted to supply this water to the difierent local units 53 ofthe various zones.

Each zone is provided with a control instru-. ment, generally designated 51, which may be conveniently located at any desired point either within or without the enclosures of the zone served thereby, and comprises a device known as the Aerotherm, manufactured by Webster- Tallmadge & Co. Inc.

When the control .device 51 serving zone A indicates a demand for cooling of the enclosures served by the local units 53 of zone A, control line 58 leading from the control device 51 serves to open the three-way or proportioning valve 59 so that the pump 60 draws cold water from the header 56 upwardly through pipe 6| and delivers this cold water through pipe 62 to the cold water riser 63. Under such operating conditions the control device 51, through control line 64, operates to adjust the proportioning valve 65 in such manner that flow from the pipe 62 to the pipe 63 is unimpeded. Thus, cold water may be delivered from the pipe 63 to each of the units 53 through lateral connections such as 66, and this water may then be returned through pipe 61 to the cold water return line 32 at the suction side of draw water not only through pipe 61 from the header 56, but also through by-pass line 68 lead- It will be understood that the control device 51, by varying the proportions of water drawn from the supply header 56, and from the return line 61, will effect a variation in the temperature of the water deliver-eds. to the units in accordance-with variations in load requirements.

Under winter operating conditions, or whenever heating is required, as indicated by the ascaou control device 61, the proportioning valve 63 is so adjusted that the pump 66 draws water only through the by-pass connection 66 from line 61. The water then delivered from the pump passes to the proportioning valve 66 through line 62 or line 63, or both, in varying proportions controlled by the valve 65 under control of device 51. The line 63 contains a heater 16 which receives steam from header 36 under the control of valve H, the valve 1| preferably being controlled by the control device 51 as indicated by the dotted line 12 leading to the control line 6|. 'Thevalve 1| is normally fully open whenever heating is required, the modulation of heating efiect being accomplished by the routing of different por; tions of water through the heater 16 and through the pipe 62.

Under summer operating conditions the water discharged from the valve 66 passes to the units through line 63 and is returned therefrom through I However, under winter operating conline 61. ditions when automatic control of the local units 63 is employed, as in zone A, it is preferred to reverse the circulation. Thus, under winter operating conditions,-hot waterdelivered from the proportioning valve 65 is routed through cross-over pipe 12 to pipe 61 by suitable adjustment of three-way valve 13, and water returning from the local units passes through pipe 63, thence through cross-over pipe 16 by suitable adjustment of three-way valve, and then returns to the inlet of pump 60 through line 68.

Suitable shut-ofi valves 16 and 11 are provided for isolating the entire piping arrangement of each zone from the central conditioning apparatus if this should be desired.

Under winter operating conditions when no cooling is required, the circulation through the cooling coil 23 of the central station conditioner 25 is interrupted and in such case the shut-cit valves 18 and 19 are closed to isolate the central station water circulating system from the water circulating system of the various zones. However, under winter operating conditions, or whenever the central station water circulating system is inoperative, the valve in line 81 is opened to make available to the water circulating systems of the various zones the function of the expansion tank 56. When the central station water circulating system is operative and is operatively connected with the water circulating systems of the various zones, valve 86 is closed. a

The piping and control arrangement for zone B, in which the units are controlled manually, is. substantially as described in connection with zone A, except that it will be noted that valves 13 and 15, and the cross-over pipes 12 and. 14, are omitted. In all other respects, the piping arrangement and basic control scheme is the same as described in connection with zone A, and therefore no detailed description is deemed required with respect to zone B.

In the operation of the central station conditioning apparatus, the primary air is reduced to a low dewpoint. When water or brine is used for this purpose in the manner illustrated in Fig. 1, the heat exchange surface is so designed that the brine returning from the coil 29 is at a higher temperature than the air leaving the conditioner casing 25. Since it is the brine from return line 32 which is supplied to the local units 53 to efiect cooling thereat, it will be appreciated that the brine delivered to the local units tube maybe 01' the order of will generally always be above the dewpoint of the air in the conditioned enclosures so that no 'mois- 'ture will be condensed in the localunits. This is true in all cases except on starting up of the .system in a humid atmosphere or where there is a relatively high latent heat load in the cone ditioned enclosure tending abnormally to increase the moisture content of the air therein.

Each local unit 53, containing a heat exchanger ment H9 is filled with a volatile fluid adapted to expand and contract with changes in temperature, such as ether, and the control element H9 is placed so that the control element reflects the temperature within the enclosure served by the unit. The control element is preferably shielded in any desired manner from the heating or cooling efl'ect of the coil 99 so as to insure more accurate control.

faces I42. The arrangement of levers I35 and I31 is employed for the purpose of multiplying the motion of the primary control rod. Thus for a given movement of the valve rod I33 the corresponding movement of valve rod I39 may be four or flve times as great. This amplification makes for increasedsensitivity and refinement of control and makes it possible to maintain within very close limits the desired temperature in the conditioned enclosure.

The valve seat serving the upper face I42 is formed m a partition plate I43 provided between,

the upper connection I04 and the center connection I05 of the valve. The seat I44, cooperating with the lower face I42 of thevalve member I. is disposed between the central connection I05 and the bottom connection I06 of the valve. Spring I45, operating on valve guide I 45, biases the valve in an upward direction.

Under summer operating conditions, or when ever cooling is required, a temperature higher than that desired required an increased flow of Through the top cap I22 of the valve there extends adjustable rod I23 bearing against a flanged discor the like I24. The rod I23 is provided with a control handle II2 for use in adjusting the setting of the valve.

The flange I24 is secured in a gas-tight manher to the upper extremity of an expansible bellows I25, the lower extremity of the bellows being secured in a fluid-tight manner to a disc I26.'

The pressure tube I leads from the interior of the thermal element II9 to the interior of the bellows I25 so that as the temperature affecting the control element H9 is varied, the bellows I25 is caused correspondingly to expand and contract. A stud I21 extends within the interior of the bellows to decrease the free volume in the bellows, as this insures a. more prompt and sensitive operation of the valve. The disc I26 is connected to a rod I28 extendin downwardly therefrom and bearing a flange I29 at its lower extremity. The rod I28 extends within acupshaped member I30 and the flange I29 provides for retention of the rod I28'within the member I30 so that as the rod I 28 is raised the member I30 will be raised correspondingly. A spring I3I, extending between the bottom of disc I25 and the top of member I30, tends to maintain maximum separation of these two elements. The lower portion of member I30 carries a disc I3Ia to which there is connected, in a fluid-tight manner, a sealingbellows I32, and also a rod I33 excooling medium through the valve. Under winter operating conditions, however, a temperature higher than normal calls for a decreased rate of flow of heating medium through the .coil. To render the local unit entirely automatic so that itssingle valve may-provide for the accurate control of temperature under both summer-and winter operating conditions, the flow of conditioning fluid to and from the local unit is reversed as explained above'in connection with three-way valves 13 and '15 and cross-over connections 12 and 14.

Considering 1 the "piping arrangement serving heat exchanger coil 99, under. summer operating conditions, as explained in connection with Fig. 1, cooling medium is supplied through line 63, and thus enters the valve through the central connection I05. Assuminga demand for cooling to exist, the high temperature affecting the control element II9 will cause depression of the valve HI and thus some of the liquid entering the valve at connection I05 will flow upwardly and out of the valve through I04 and through line I41 to the heat exchange coil 99. The conditioning medium passing from the coil is routed through line I48 to junction I49 and then passes through pipe I50, containing check valve I50a, to line 61 and is thus returned from the local unit. The portion of the conditioning medium supplied to the valve which is not so routed, passes downwardly in the valve past the valve seat I44" and is discharged through connection I06 to line I5I through which it passes to junction I49, where this fluid is joined with the fluid discharged from the conditiom'ng coil 99 and is returned therewith to the tending through a plate I34 to which the bellows I32 is connected. Thus, the operating fluid of the thermal element is prevented from escaping within the valve and also the water or brine controlled by the valve is' effectively prevented from escaping within the valve.

The rod I33 bears downwardly upon a lever I35 pivoted at I36. The free end of the lever I 35 bears downwardly upon a lever I31, pivoted at I38, at a point proximate the fulcrum I38. The lever I31 is adapted to actuate the valve stem I39 which is operably connected through a. star-shaped-guide I40 to a valve closure member I, comprising a pair of oppositely arranged line 61. As more conditioning is required under summer operating conditions, more cold liquid is circulated throughthe conditioning coil 99 and less is bypassed through I06, and as less; conditioning is required less cold liquid will be supplied to the coil 99 and more will be bypassed through I06.

Under winter operating conditions reverse operation occurs, and in this case an increased 1 temperature affecting the thermal control element H9 results in decreased supply of conditioning medium, which is then at a relatively high-temperature, to the conditioning coil. Under winter operating conditions, conditioning medium. is supplied through line 61 and passes through the branch line I52 containing check valve I52a, to junction I53. Part of the conditioning medium travels through the pipe I41- and enters the valve at connection I04 and passes downwardly therein and is discharged from the valve through connection I05. The other portion of the conditioning fluid passes from the junction I53 to the con-v ditioning coil 99, is discharged therefrom through lin I40 and through connection I5I, and enters the valve at I and is discharged therefrom through central opening I together with the fluid which was bypassed through connection I41. As the temperature affecting the thermal control element II9 rises, the valve I4I will be lowered and hence more of the condi-' bypassed.

When the valve controlling the action of the heat exchange coil 99 is controlled manually, there is no necessity for reversing the flow of the conditioning medium throughthe pipes 63 and 61 as in the case of automatic control in the manner just. described, since an; operator can readily turn the valve in either direction as rethat as the handle is rotated,.the valve stem is correspondingly rotated and raised or lowered by means of the threads 205 to provide the desired adjustment of position of the valve closure member'.l4 l.

.Within thechannels 203 and 204 there ispositloned the stem 201 of a thermal indicator having a rotating disc 208 mounted at the top thereof and within a recess 200 formed in the top oithe handle lI2a. The recess is covered by a closure plate 2I0 which is provided with an aperture 2 through which a portion of the indicator plate 208 may be seen. A screw 2I2, or similar means, is employed to rotate the stem of the thermal quired to bring about the desired change in the conditioning action. Thus, under sunmieqoperating conditions, whenthe local unit is supplied.

with cooling medium, if the temperature in the enclosure served by the unit'is too high the operator will depress the valve I4I so as to permit increased flow of cooling medium from opening I05 to opening I04 serving the pipe I08,-which delivers conditioning medium to the coil 99; and if the temperature is too low the operator will adjust the valve to raise the valve member I4I so that a lesser quantity of cooling medium flows through the conditioning coil 99. Under winter operating conditions, when heating medium is supplied to the conditioning unit, the operating is merely reversed. Thus, when the temperature in the enclosure is too high, the operator will raise the valve I4I to diminish the supply of heating medium to the coil 99 through the pipe I08, and if the conditioned enclosure is too cold, the

valve I4I, will be depressed to permit a greater supply of conditioning medium to the coil 99 through the connection I08.

Fig. 3 illustrates a modified valve construction adapted to be employed when manual control of the heating and cooling efiect at the local units .is desired; The valve I03 is essentially the same as the valve illustrated in Fig. 2\except for the omission of the expansible bellows and the multiplying mechanism which become unnecessary and may be eliminatedin the case of manual operation. Thus, the valve includes a casin I2I, a top cap I22 and an actuating stem I23a, the valve stem I23a being hollow to provide a longitudinally extending channel 203 therewithin. The bottom of the rod I23a bears against an adjustably positioned plate I3Ia and is adapted to cause displacement of this plate. The plate I3Ia is connected to the partition plate I34 by a sealing bellows I32, as in Fig. 2. A rod I33a extends downwardly from the plate I3Ia and is movable indicator aslthe handle 241 is rotated so that the relative positionsof the indicator disc 200 and the valve handle I I2a may remain unaffected detailed description thereof is deemed required here. One type of thermal indicator of the character indicated manufactured by the Weston Electrical Instrument Company of Newark, New Jersey, the instruments manufactured by this company, however, being generally provided with a dial pointer rather than a disc as here disclosed. As will be understood, the thermo-responsive stem 201, extending within and through the body of the valve, will respond to changes in the temperature of the fluid passing through the valve and thus will change the position of the disc 208 in accordance with such changes in temperature. The upper face of disc 208 is provided with two sets of arrow indicators pointing in opposite directions and arranged valve closure member HI and permit more con-' ditioning medium to enter the pipe I28 and thus pass to the conditioner coils.v If the room is too cool under such operating conditions the valve will he turned in a reverse direction to diminish theamount of cooling medium passing to the conditioning coil. When the conditioning medium supplied to the valve is warm another portion of the indicator disc 208 will appear through the aperture 2I I, the arrows 2I4 then indicating the direction in which the valve should be turned to provide a desired changein temperature within the enclosure.

Thus, when heating medium is supplied to the valve. turning the valve in a counter-clockwise direction will render the enclosure cooler by raising the valve closure device MI and diminishing the supplyof heat-ing medium to the conditioner coils, whereas, turning the valve handle in a reverse or clockwise direction will depress the valve closure member I and cause more heating medium to pass to the conditioner coils. It will be apparent to those skilled in the art, that instead of the word Cooler the word "Warmer might be applied on the valve handle, in which case the arrows will each point in a direction opposite-to that shown in the drawings, and that variations maybe made in the physical embodiment of the invention Since thermal indicators of this type without departing from the concept herein closed.

I claim:

1. A fluid control arrangement for an air co ditioning system comprising a heat exchange device, a valve structure for controlling the flow of heating fluid'to said device under winter operating conditions and the flow of cooling fluid to said device under summer operating conditions, 'a'thermal element and means operative responsive to variations in temperature under winter and summer-operating conditions afiecting said element for causing said valve structure to operate, said valve structure including a first port, a"

second port, a third port, a double seated port control member, the flow of fluid through said three ports being regulated by the action of said port control member, andmeans operative upon a rise in temperature under summer operating conditions for routing cooling fluid'from a source of supply in part in a flow circuit including said second port, third port, heat exchange device and a return line, and in part through said second port, first port and the same return'line, the proportions of fluid passing through said flow circuits being varied responsive to changes in conditions affecting the thermal element, said means being operative upon a rise in temperature under winter operating conditions to route heating fluid through a difierent flow circuit including the same portsand heat exchange device.

2. A fluid control arrangement for an air conditioning system comprising a heat exchange device, a valve structure for controlling the flow of heating fluid to said device under winter operating conditions and the flow of cooling fluid to said device under summer operating conditions, a thermal element and means operative responsive to variations in temperature under winter and summer operating conditions affecting said element for causing said valve structure to operate, said valve structure including a first port, a second port, a third port, a double seated port control member, the flow of fluid through said three ports being regulated by the action of said port control member, and means operative upon a fall in temperature under winter operating conditions for routing heating fluid from a source of a supply in part in a flow circuit including said heat exchange device first port, second part, and a return line, and in part through said third port, second port, and back to the same return line, the proportions of fluid passing through said flow circuits being varied responsive to changes in conditions aflecting the thermal element, said means operative upon a fall in temperature under summer operating conditions for routing cooling fluid in a different flow circuit including said heat exchange device and ports.

3. In a fluid control arrangement of the character described, a first conditioning medium line, a second conditioning medium line, means, for

routing heating conditioning medium through,

routing conditioning medium from one of said lines in a desired ratio with one part flowing through said heat exchanger and two of said ports and the remainder of the medium flowing through one of said last two mentioned ports and the third port, the ratio being varied responsive to variations in the position of said valve, said means being operative responsive to variations in atmospheric conditions during other seasons of the year for routing cooling conditioning medium in a diflerent flow arrangement through the same ports and exchanger.

4. In a fluid control arrangement according to claim 3, means for routing a constant volume of fluid substantially at a constant rate through said lines, and means for assuring the flow of diflerent proportions of said fluid through said ports in the desired directions.

5. A valve arrangement oi the character described comprising a housing structure, an upper section of said structure containing an actuating element, a driving rod in said section; a volatile fluid in said element arranged to move said rod responsive to expansion and contraction of said fluid, a conditioning fluid lower section of said structure, a driven rod in said lower section, a valve closure member connected to said driven rod, an intermediate section connected to said upper and lower sections, a sealing bellows for preventing the volatile fluid in the'upp'er section and conditioning fluid from the lower section from escaping within the valve, movement multiplying mechanism in the structure for relaying a movement of the driving rod to the driven rod, three fluid passages in the lower section, said valve closure member being located in one of said passages and operative responsive to moveinent of the driven rod to apportion the flow oi fluid in desired ratio from a single source through said passages.

6. A valve arrangement of thecharacter described comprising a valve housing a first passage,

said lines under winter operating conditions and cooling conditioning medium through said lines under summer operating conditions, a heat exchanger connected to said lines, a proportioning a second passage, a third passage, all said passages being formed in the housing and connecting with each other, a doubleseated closure device in the second passage, means operative responsive to changes in atmospheric conditions for actuating said device in such manner that fluid could be permitted to flow between said second and one of the other passages while barred from flowing between said second and the remaining passage, a heat exchanger for conditioning air, fluid supply and return lines, and a plurality of conduits connecting said lines to said passages and ex-v changer, means operative under summer operating conditions, upon-a rise in atmospheric temperature, for routing an increasing volume of cooling fluid through the first of said passages feeding the heat exchanger and bypassing the remainder of the cooling fluid fed to the valve around the heat exchanger through the third passage, means operative under winter operating conditions, upon a fall in atmospheric temperature, for routing an increasing volume of heating fluid through the third passage feeding the heat exchanger and bypassing the remainder of the heating fluid fed to the valve around the heat exchanger through the first passage, the direction of fluid flow through said fluid supply and return lines under winter operating conditions being the reverse of that under summer operating conditions.

' WILLIS H. CARRIER.

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