US3433025A

US3433025A - Air conditioning system

Info

Publication number: US3433025A
Application number: US674499A
Authority: US
Inventors: Alwin B Newton
Original assignee: Borg Warner Corp
Current assignee: York International Corp
Priority date: 1967-10-11
Filing date: 1967-10-11
Publication date: 1969-03-18
Anticipated expiration: 1986-03-18
Also published as: NL6814434A; DE1801768A1; FR1585595A

Description

March 18, 1969 A. B. NEWTON AIR CONDITIONING SYSTEM Filed Oct. 11, 1967 C re d w a a 0 v WW E E N w m z W?!) g l/.N\ D m M w w. 2 w w E w A].

D.C. POWER SUPPLY TO RETURN AIR SYSTEM, OR OUTDOORS ZONE 5 INVENTOR ALW/Nfi NEW7'0/V BYWJM ATTORN EV United States Patent 3,433,025 AIR CONDITIONING SYSTEM Alwin B. Newton, York, Pa., assignor to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois Filed Oct. 11, 1967, Ser. No. 674,499 US. Cl. 62-3 Int. Cl. F25b 21/00 7 Claims ABSTRACT OF THE DISCLOSURE Background of the invention;

This invention relates to air conditioning systems. More particularly, it relates to air conditioning systems wherein thermoelectric elements are employed to effect desired temperature and humidity control of conditioned air sup plied from a central source to separate areas or zones with unequal loads.

In many situations, air conditioning systems used to control the temperature and humidity in a given area experience unequal loads between zones of the area to be served. For example, during the winter, the area about the perimeter of a building may be relatively cool in comparison to its core, while the situation may be the opposite during the summer. Furthermore, the temperature and humidity load in an area of the perimeter or the core may vary considerably in a given time period. The load requirement will depend upon the intensity of sunlight impinging on the walls and windows of the building, the heat dissipated in the area from ofiice equipment and similar apparatus and other variable factors.

Systems for controlling the temperature and humidity in situations such as those described above have been proposed and used; however, each of them has been unsatisfactory, for reasons of extreme complexity or excessive cost or lack of effectiveness.

Accordingly, it is a principal object of the present invention to provide an improved air conditioning system which is effective to compensate for variable zone loads.

Summary of the invention Very generally, the present invention includes a thermoelectric element or apparatus mounted in a supply duct in a manner such that the conditioned air supplied by a central air conditioner source is divided into separated streams which are selectively acted upon and coupled to line ducts extending into the area or zones of varying load. Utilizing the thermoelectric device, heat can be pumped from the stream flowing from the supply duct to one line duct to the stream flowing from the supply duct to another line duct. Alternatively, the operation can be reversed to supply colder air to the area or zone supplied through the other line duct by reversing the current flow to the device. Selective heating or cooling also can be provided by employing bypass dampers which determine whether the conditioned air is returned to the air system of the air conditioner supplying the system, rejected outdoors, or otherwise utilized.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction ice hereinafter set forth, and the scope of the invention will be indicated in the claims.

Description of the drawings For a fuller understanding of the nature of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing in which:

FIGURE 1 is a schematic block diagram generally illustrating an air conditioner system having a thermoelectric element installed therein, in accordance with the present invention;

FIGURE 2 is a perspective view, partially broken away, of the thermoelectric element of the system of FIGURE 1;

FIGURE 3 is a detailed perspective view of one of the strings of the thermoelectric elements and heat exchange fins used in the unit of FIGURE 2; and

FIGURE 4 is a partial block diagram, generally illustrating the manner in which the conditioned air in a line duct can be directed for subsequent utilization or rejection outdoors.

Detailed description Referring now to the drawing, in FIGURE 1, there is illustrated, in block diagram, an air conditioning system 10 exemplary of the invention including a supply duct 12 which is coupled to a central air conditioning unit or source 14, and which supplies conditioned air to a thermoelectric element or apparatus 16 which in the illustrated embodiment is of the cross-flow type. That is, the apparatus 16 is of the type which includes separated flow paths comprised of alternating sections which direct one stream of air at right angles with respect to another stream. In this respect, the apparatus 16 preferably is a thermoelectric apparatus of the type disclosed in copending United States patent application, Ser. No. 625,392, filed Mar. 23, 1967, by Alwin B. Newton. It should be understood, however, that a counter flow or parallel flow heat exchange system would also be operable.

More specifically, as fully explained in the abovementioned copending application, the apparatus 16, as can be best seen in FIGURES 2 and 3 includes alternate groups of

sections

18 and 20 defining flow passages for streams of air passing at approximately right angles to each other.

A plurality of heat exchange fins 22, 24 extend across the

flow paths

18 and 20, respectively. These

fins

22, 24 are in thermal and electrical contact with alternating N and P-

type thermoelements

26, 28, respectively, extending between adjacent fin sections. The thermoelements entered between adjacent sections and are arranged such that current flow in one direction will provide for pumping of heat from the sections 18 to the sections 20 and reverse current flow will provide for pumping of heat in the opposite direction.

As fully described in copending application Ser. No. 625,392, the

fins

22, 24 act as both heat transfer elements and as electrical conductors to conduct the unidirectional electrical energy in series through the thermoelements. Bus bars 30 at opposite ends of the unit conduct current from one string of thermoelements and fins to an adjacent string. The unidirectional electrical energy, supplied by some suitable source such as the DC power supply 32, is connected to a first terminal 34 and flows through the string at the lower right-hand section of the unit, as illustrated in FIGURE 2, to the opposite end. Each of the strings is electrically insulated from an adjacent string by epoxy resin or other suitable insulating material 36. The current emerges from the opposite end of the string to be transferred by a bus bar (not shown) to the superjacent string. Flowing from right to left in the latter string, it reaches the left-hand end of the module and passes through bus bar 30a to another superjacent string and so forth through the entire unit until it emerges at terminal 38 connected to the other side of the D-C power supply 3 2. Current passing into the plane of the bus bars, as shown in FIGURE 2, is denoted by and current passing out of the plane is denoted by 0.

As can be best seen in FIGURE 3, each of the

thermoelements

26, 28 is soldered, or otherwise mechanically and electrically secured, between a pair of generally rectangular conductor plates 42 of copper, aluminum or other suitable material. The other side of plates 42 are soldered or otherwise secured to the

fins

22 and 24. The space surrounding the thermoelements may be filled with insulating material 44, such as polyurethane foam, or other suitable material having low thermal conductivity and good moisture resistance.

The thermoelectric conditioning apparatus 16 is positioned with respect to the supply duct 12 so that the conditioned air from the central air conditioned source 14- can simultaneously flow through

sections

18 and 20 in one direction (indicated by the arrow 46 and hereinafter referred to as circuit 46) to a line duct 48 and in another direction (indicated by the arrow 50 which is hereinafter referred to as circuit 50) at a right angle to the first, to a line duct 52. The line duct 48 couples the conditioned air from the apparatus 16 to a zone A which may be, for example, an area or room on the perimeter of a building. The

. line duct 52 likewise couples the conditioned air from the apparatus 16 to a zone B which may be, for example, in the core of the building.

In operation, conditioned air is supplied from the conditioned air source 14 through the supply duct .12 to the apparatus 16 at a temperature suitable for most of the zones served usually at 55 to 65 F. Power is supplied to the apparatus 16- by the D-C power supply 32. A switch 54 for reversing the polarity of the power supplied thereto advantageously is provided, for controlling the operation of the apparatus 16 in the well-known manner and as described more fully below. Any suitable means (not shown) also can be provided for controlling the level of D-C voltage applied to the apparatus 16.

If local cooling or dehumidification is needed, the apparatus 16 is operatively energized. The thermoelements effect pumping of heat from the stream of conditioned air passing through the sections 18 to the stream of conditioned air passing through the sections 20. The cooled and dehumidified air passing through sections 18 then flows through line duct 48 to zone A. The heated stream of air passes along circuit 50 through duct 52. By choosing the air quantity through circuit 46 so that the temperature of the conditioned air supplied to line duct 52 is equal to the temperature in zone B, the sensible heat load of zone B is not effected. Conversely, the conditioned air supplied to zone A through circuit 46 of the apparatus 16 and the line duct 48 effectively reduces the sensible heat load of that zone. Reducing the quantity of air through circuit 50 adds to the room sensible load in zone B, so that control of the room sensible load is possible.

If added cooling and dehumidification is needed in zone A supplied by line duct 48, the conditioned air supplied to line duct 52 is directed by means of bypass dampers, for example, bypass dampers 56, as illustrated in FIG URE 4, to the return air system of the air conditioner source 14, or it may be rejected to atmosphere.

Where adjacent zones have oppositely varying heat sensible loads, the conditioned air through circuit 46 to line duct 48 is supplied, cooled and may be dehumidified, as described above, While the heated conditioned air through circuit 50 to line duct 52 is supplied to a zone needing less cooling. In an opposite season, the heat sensible load conditions in each of these zones may reversibly change. In such cases, the switch 54 is reversed to operatively energize the apparatus so that the conditioned air in line duct 52 is cool and the conditioned air in line duct 48 is heated.

A thermostat 60 advantageously can be provided in one of the zones, such as the zone A, as illustrated, for controlling the D-C power supply 32 to energize the apparatus '16, in accordance with the requirement for conditioned air in that zone. The thermostat 60 likewise can be adapted to control the operation of the switch 54, to automatically switch it to reverse the operative condition of the apparatus 16, if desired.

A complete air conditioning system may include a number of systems like the system 10 placed in various predetermined strategic positions within a building. A modulated central air conditioner source such as the source 14 can thereby be easily adapted to handle the building's average sensible heat load. A number of thermoelectric elements or apparatus like the apparatus 16 are installed at convenient locations to provide the needed trimming of the conditioned air supplied to these locations, as required.

It can be seen from the above description that the thermoelectric apparatus 16 can be easily installed inconventional air supply ducts. It is only necessary to provide that the conditioned air from the air conditioning source 14 flow through both the

circuits

46 and 50 simultaneously and that line ducts are provided to convey the conditioned air from the apparatus 16 to the various zones or areas to be air conditioned. Appropriate voltage regulating means are provided to control the degree of energi- Zation of the thermoelectric apparatus 16 to provide conditioned air at the desired temperature and humidity. In addition, switch means are provided to reverse the operative state of the thermoelectric apparatus 16. Thermostats and humidistats can be provided to automatically control the supply of power to the apparatus 16, as desired. Additional trimming of the conditioned air supplied to a particular zone or area can be provided by means of individual units like the apparatus 16, installed and operated in the conventional manner.

Various features of the invention have been particularly shown and described in connection with the illustrated embodiments of the invention. However, it must be understood that these particular arrangements are for illustrative purposes and that the invention is to be given its fullest interpretation within the terms of the appended claims.

What is claimed is:

1. An air conditioning system including: a source of conditioned air; a conditioned air supply duct connected to said source; a thermoelectric apparatus disposed within said supply duct to receive said conditioned air, said apparatus being divided into sections defining at least two separated flow paths for said conditioned air, and including a plurality of thermoelements disposed between said separated flow paths to pump heat from the conditioned air in one of said flow paths to the conditioned air in the other upon energization of said elements; a source of power connected to said thermoelectric apparatus for energizing said thermoelements, and at least one line duct connected to one of said flow paths to receive conditioned air therefrom, said line duct being connected to a zone to be conditioned.

2. An air conditioning system as claimed in claim 1, wherein said thermoelectric apparatus is of the crossfiow type.

3. An air conditioning system as claimed in clam 1, wherein a pair of line ducts are provided each one of which is connected to one of said separated flow paths to receive conditioned a-ir therefrom, said line ducts being connected to separate zones of an area to be conditioned.

4. An air conditioning system as claimed in claim 3, wherein said system further includes bypass damping means in at least one of said line ducts, and a venting line duct coupled to said line duct, whereby the air flowing through said line duct can be coupled back to said air conditioning source or rejected to atmosphere.

5. The air conditioning system of claim 3, further including switch means for reversing the polarity of the source of power coupled to said thermoelectric apparatus.

6. The air conditioning system of claim 3, further including temperature sensitive control means in the zone supplied conditioned air by at least one of said line ducts for controlling the operation of said source of power to selectively energize said thermoelements,

7. The air conditioning system of claim 3, further including a thermoelectric apparatus positiona-bly mounted in at least one of said line ducts for trimming the conditioned air supplied to the area or zone serviced by said one line duct.

References Cited UNITED STATES PATENTS WILLIAM J. WYER, Primary Examiner.

U.S. Cl. X.R.