US3500655A - Heat exchange apparatus - Google Patents

Description

March 17, 1970 J. c. LYONS 3,500,655

HEAT EXCHANGE APPARATUS Filed May 2, 1968 JOE C. LYONS INVENTOR.

.F/G.3 W rvw ATTORNEYS United States Patent O 3,500,655 HEAT EXCHANGE APPARATUS Joe C. Lyons, 5705 Alvarado, Houston, Tex. 77035 Filed May 2, 1968, Ser. No. 725,981 Int. Cl. F25b 39/04; F25d 23/12 U.S. Cl. 62-183 11 Claims ABSTRACT OF THE DISCLOSURE Waste heat from the condenser of a refrigeration system as used in commercial buildings is exhausted to the outside environment in the summer, or reclaimed for heating the interior of the building in the winter, by a mechanism using a reversible fan along with one-way, self-operating check valves to direct the flow of air. A pair of opposing fans, only one operable at one time, may be used in place of the reversible fan. The fan or fans may be controlled by the interior or outdoor temperatures.

BACKGROUND OF THE INVENTION Commercial buildings such as food stores may contain many refrigeration units as used for display counters, freezers, and the like. Often, the waste heat from the condensers for these refrigeration systems is dissipated into the room in which the freezer or refrigerator is located; this provides uncontrolled heating in the Winter for the interior, but in the summer an undue and wasteful load on the air-conditioning equipment for the building is imposed. Systems have been devised for exhausting the heat outdoors in the summer, but reclaiming the heat in the winter, by providing two sets of condensers, one located indoors and the other outdoors, along with corresponding duplicate controls and fans. While such arrangements have been known for some time, the cost of providing.

duplicate machinery outweighs the expense of the added load on the air-conditioning equipment, except for quite large systems.

In order to provide the function of exhausting the waste heat in the summer but reclaiming it in winter, systems have been devised which use only one condenser, but employ elaborate air flow control mechanisms, usually motor operated, for causing outdoor air to flow across the condenser in summer, and indoor recirculating air to flow across the condenser in the winter. The expense of constructing the mechanical control mechanism for accomplishing this function, as well as the difiiculty in maintaining this machinery in the remote locations and adverse environmental conditions typical for such installations, has rendered this approach uneconomical in many respects.

It is therefore a primary feature of the present invention to provide apparatus for use with a refrigeration system within a building, to exhaust the waste heat from the refrigerator condenser during summer but reclaim it during winter, without requiring duplicate sets of condensers and fans, and without requiring elaborate mechanical controls for directing the flow of air to and from the space being heated or to and from the outside, i.e., across the condenser. A particular feature of the invention is the elimination of mechanically or electrically operated dampers or shutters as have been used for the purpose of diverting the fiow of air to or from a refrigeration condenser to reclaim heat or to exhaust heat to the outdoors. Another feature is the location of the condenser and all air flow control chambers and ducts exterior to the space to be temperature-controlled, in apparatus of the character described.

SUMMARY In accordance with a preferred embodiment of the invention, a heat exchanger such as the condenser for a refrigeration system is located in a housing, preferably positioned on the roof or otherwise outside of the temperature-controlled area, with a reversible fan or the like adapted to force air through the condenser in either direction in accordance with whether heat is to be reclaimed or exhausted. Chambers on each side of the condenser and fan are each connected to the interior and to the exterior space by means of one-way, self-operating check valves or shutters, so that when the fan is forcing air in one direction, the air will enter freely from the outdoor side and be exhausted outdoors, whereas when the fan is operating in the other direction the outdoor vents will automatically close and the indoor vents open so that air is drawn from inside the building and returned to the interior. No control mechanisms of the solenoid or mechanical type are needed to operate the vents, which may be located in a remote, inaccessible position. Either a single fan with a reversible motor, or a pair of fan and motor combinations, pointed in opposite directions may be used. While described in the context of a refrigeration system in a building, with the heat exchanger being a conenser, it is understood that the system is applicable to heat exchangers in general.

Novel features which are believed to be characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof, may be best understood by reference to the following detailed description of particular embodiments, when read in conjunction with the accompanying drawings, wherein:

THE FIGURES FIGURE 1 is a schematic illustration of a building containing a refrigeration system and heat reclaiming or exhaust apparatus, according to the invention;

FIGURE 2 is a view of a portion of the system of FIG- URE 1, in another condition of operation; and,

FIGURE 3 is a sectional view of apparatus similar to FIGURES 1 and 2, in accordance with another embodiment of the invention.

It will be noted that like parts, when appearing in several views of the drawings, will bear like reference nurnerals. Also, it is to be understood that the accompanying drawing forms a part of this specification and is incorporated herein.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT With reference now to FIGURE 1 of the drawing. refrigeration apparatus according to the invention is illustrated in schematic form as being mounted within, and on the roof of, a building 10. A refrigerated compartment 11 is located within the interior 12 of the building; typically, the refrigerated compartment would be a freezer or refrigerated vault as might be used in a store or other commercial or manufacturing building. While the refrigerator 11 is to be maintained cold, the interior space 12 of the building is to be maintained at a comfortable temperature for occupancy. Accordingly, a conventional refrigeration system is provided, including cooling coils 13 within the refrigerated space, along with a compressor The condenser 15, located within a housing 17 shown ositioned on the roof of the building 10, is also of conentional design and is adapted to receive the output of re compressor 14 and cool' this refrigerant and return in liquid state under high pressure to the expansion alve and thus to the cooling coils. Air is forced through 1e condenser 15 by a fan 18, usually positioned within circular duct 19. Rotation of the fan 18 will force air trough the condenser 15 in the customary manner.

An important feature of the invention is that the fan 8 is adapted to force air through the condenser 15 in ither of two directions depending upon the temperature f the outdoor environment, or upon the indoor temerature, as will be described. To this end, the fan 18 a driven by a reversible motor, 20 which, depending pon the polarity of energization, is effective to force ir either to the right or to the left through the evapoator 15 in the configuration shown in the figures.

When the motor 20 is turning the fan 18 in one direclon, a chamber 21 on one side of the condenser will end to develop a negative or less than atmospheric presure, as air will be drawn out of this chamber, while chamber 22 will develop a slight positive pressure. When he fan is turning in the opposite direction, the reverse ituation is present. Each of the chambers 21 and 22 is ented to the interior 12 of the building and also to the xterior area 23 by means of sets of doors or one-way alves 24-27. These doors 24-27 function as check valves, .nd therefore permit air to flow in one direction but not 1 the other. The doors 24 open freely to permit air a flow in the direction indicated by the arrows in FIG- JRE 1, thus permit air to flow into the chamber 21 then the chamber tends to be at less than atmospheric ressure, but these doors 24 close when the chamber 21 s at a pressure greater than atmospheric. The doors 25 ermit air to flow from the chamber 21 into the interior .2 of the building, but prevent air from flowing from he building into the chamber. The set of valves 26 and ,7 function in the same manner but are positioned on he opposite sides. Thus, air'can flow from the chamber 2 to atmosphere 23, but not from the chamber into he interior 12. Similarly, air is permitted to flow from he interior 12 into the chamber 22 when the fan is turnng in the opposite direction, but not from the outside .tmosphere 23 into the chamber through the valves 26.

The doors or valves 24-27 are hinged as illustrated, nd may be spring biased toward a closed position to id in the enumerated functions. To prevent undesirable toise due to flapping of the valves, 'dashpot-type mech- .nisms may be used since the valves need not operate uickly and will remain in the same position for long eriods of time.

The direction of air flow will be as shown in FIGURE during the summer, or when the heat dissipated in he evaporator 15 is not to be used for heating the interior .2 of the building. On the other hand, the air flow will to in the direction indicated in FIGURE 2 when the tutside temperature is low and the space inside is to be .eated.

To control the direction of rotation of the reversible motor 20, a control unit 28 is used, this being connected y lines 29 to the motor itselfin the usual manner. The ontrol unit 28 may comprise a conventional thermostat vhich is responsive to the temperature in the interior pace 12 in a manner such that when the interior temterature is in excess of a specified level the motor will 1e energized to turn the fan to cause air flow as in FIG- JRE 1, whereas when the temperature is below a cerain level air flow as in FIGURE 2 will be caused by re- 'ersing the motor. Instead of using the temperature withn the space 12 as the controlling factor, the exterior emperature in the area 23 may be used, or the temper tture of the air flowing through the condenser within the mousing 17 may be used as the controlling factor. In simiar manner, the control unit 28 may be responsive to the pressure or temperature within the line 16, as these variables will be at least in part a function of the exterior temperature conditions.

Instead of using a single fan with a reversible motor, it may be preferable in some situations, especially for small units, to use a pair of motors 30 and 31, each driving one of a pair of fans 32 and 33, as seen in FIGURE 3. One of the fan-motor combinations is adapted to force air in one direction, while the other forces air in the opposite direction. Only one of the motors 30 and 31 would be energized at any one time. The combination of two fans and two motors, pointing in opposite directions, would function in exactly the same manner as the reversible motor and fan of FIGURES l and 2, and this arrangement would be controlled by a-unit 28 as pr viously described; one of the motors would be energized when the outside temperature is high, while the other would be energized when the outside temperature is low.

It should be emphasized. that the shutters or valves 2427 are self-operating and do not require electrical or mechanical operating means, nor controls. The only operation needed to change from a heating cycle to a heat rejection cycle is to either reverse the direction of the fan in the FIGURE 1, FIGURE 2v embodiment, or to turn off one fan and turn on the other in the FIGURE 3 embodiment. Also, in contrast to some of the previous structures for providing a similar function, duplicate condensers are not needed.

It is preferable that the condenser or the like 15 be located in a housing which is positioned outside the building or space to be controlled in temperature. That is, it is preferable that the housing be positioned on the roof or outside the exterior wall of the building 10. The reason for this is that during the summer months when the interior space is air-conditioned, the heat rejection cycle should be 'working at optimum efiiciency. If the condenser 15 and the housing 17 were located within the building, the interior space 12 would be heated not only by the condenser 15 but also by the hot outdoor air which is circulating through the housing 17. Thus, it is preferred that the mechanism be more eflicient on the heat rejection cycle or summer operation, than on the heating cycle or winter operation, since ordinarily the expense of heating air is less than that of cooling similar volumes of air.

It may be noted that the compressor 14, or compressors if several are used, may be located within the housing 17 in some refrigeration systems. Also, several complete refrigeration systems may be used, each having a separate condenser 15 located within the housing 17, all using a common fan and motor 18 and 20. Certainly, multiple fans and motors may also be used, all forcing air in the same direction as in FIGURES l and 2, or alternate pairs of fans and motors functioning in the manner explained with reference to FIGURE 3.

Contrary to the embodiment shown in FIGURE 1, it is important to note that the apparatus of the invention may be arranged to heat a space other than that containing the refrigerator or freezer. For example, the cold room or display case may be located in one area of the store, while the apparatus of FIGURE 1, during the heating mode of operation, may be used to heat a separate area or room of the store.

Accordingly, while the invention has been described with reference to particular embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as Well as other embodiments of 'the invention, may occur to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.

What is claimed is:

1. In a heat exchanger system:

first and. second chambers with a heat exchanger positioned generally between such first and second chambers,

means for forcing fluid between the first and second chambers past the heat exchanger in either direction,

a first space to be temperature-controlled, and a second space,

one-way, self-operating valve means coupling each of the first and second chambers to each of the first and second spaces, whereby fluid is withdrawn from the first space and returned thereto when the fluid is being forced past the heat exchanger in one direction, or is Withdrawn from the second space and returned thereto when the fluid is being forced past the heat exchanger in the other direction.

2. Apparatus according to claim 1 wherein the heat exchanger includes a condenser for a refrigeration system primarily located in one of said first and second spaces. a

3. Apparatus according to claim 1 wherein the means for forcing fluid includes a fan or blower which is reversible in direction.

4. Apparatus according to claim 1 "wherein the means for forcing fluid includes at least a pair of fans or blowers which are operable to force air in opposite directions, only one of which is energized at any one time.

5. Apparatus according to claim 1 wherein the valve means includes hinged shutters.

6. Apparatus according to claim 1 wherein the means for forcing fluid in either direction is controlled in response to a condition in one of said first and second spaces.

7. Apparatus according to claim 1 wherein the first space is the interior of a building or the like, and the second space is an exterior or outdoor area, and the heat exchanber is a condenser for dissipating waste heat.

8. Apparatus according to claim 7 wherein the heat exchanger and the first and second chambers are located exterior to said first space.

9. Apparatus according to claim 1 wherein the first and second chambers and the heat exchanger are included in a housing along with said means for forcing fluid, the housing being entirely positioned 'within the second space.

10. Apparatus according to claim 9 wherein the first space is temperature-controlled by operating the means for forcing fluid, in response to the environmental temperature.

11. In a refrigeration system of the type having a condenser for condensing a gaseous refrigerant to a liquid and thereby giving off heat, an arrangement for reclaiming heat during cold weather or exhausting heat during hot weather comprising:

first and second chambers, with the condenser mounted generally between the first and second chambers,

fan or blower means for forcing air selectively in either direction through the condenser, from the first to the second chamber or from the second to the first chamber,

first one-way valve means operable by air pressure differential, positioned in communication with the first chamber, operable to admit air into the first chamber when the fanor-blo-wer means is forcing air from the first to the second chamber,

second oneway valve means operable by air pressure differential, positioned in communication with the first chamber, operable to permit air to exhaust from the first chamber when the fan or blower means is forcing air from the second to the first chamber,

third one-way valve-means operable by air pressure di'lferential, positioned in communication with the second chamber, operable to admit air into the second chamber when the fan or blower means is forcing air from the second to the first chamber,

fourth one-way valve means operable by air pressure differential, positioned in communication with the second chamber, operable to permit air to exhaust from the second chamber when the fan or blower means is forcing air from the first to the second chamber,

the first and fourth one-way valve means being in communication with exterior air space, and the'second and third one-way valve means being in communication with interior air space,

all of said one-way valve means being characterized by the absence of electrical or mechanical powered operating means, and

means for selectively energizing said fan or blower means for operating in the mode of forcing air in one or the other of said directions.

5/1959 Quick 62-183 10/1964 Quick 52 1s9 WILLIAM J. WYE, Primary Examiner US. Cl. X.R.

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