Air conditioning system with secondary compressor drive

A secondary drive system for an air conditioner compressor includes a conventional air conditioning circuit having integrated therewith a secondary compressor drive. The secondary compressor drive includes an air motor for selectively operating the otherwise conventional compressor of the air conditioning circuit and a compressed fluid source for driving the air motor. The compressed fluid source includes a pressure vessel and a collection reservoir. Heat generated in the operation of the air conditioning circuit is utilized to convert a liquid phase of the operating fluid into a highly compressed gas within the pressure vessel whereafter the resulting compressed gas is utilized to drive the air motor. The air motor operates the compressor of the air conditioning circuit. The operating fluid is captured within the collection reservoir as a gaseous or vaporous operating fluid for reuse in the system of the present invention.

FIELD OF THE INVENTION

The present invention relates to air conditioning systems. More particularly, the invention relates to an air conditioning system with provision of a secondary compressor drive system that operates on recycled excess heat energy from an otherwise conventional air conditioner circuit.

BACKGROUND OF THE INVENTION

Over the last fifty years, air conditioning, as an answer to excessively warm weather, has gone from a luxury for the privileged few to a convenience enjoyed by many. As a result, the cost of installing an air conditioning system in a home is now low enough to be easily absorbed within the price of nearly any home. Unfortunately, however, notwithstanding the relatively lower initial costs associated with purchasing and installing an air conditioning system, the costs of operating such an air conditioning system can still be prohibitively high—especially in the warmest climates where the benefits are most needed.

It is therefore an overriding object of the present invention, especially in light of ever increasing energy costs, to improve generally upon the prior art by setting forth a method and apparatus for a more energy efficient air conditioning system. Additionally, it is an object of the present invention to provide such an air conditioning system that utilizes a secondary compressor drive to capitalize upon otherwise wasted energy in a conventional air conditioning system to increase energy efficiency. Still further, it is an object of the present invention to provide such as system in a manner that does not prohibitively increase the initial costs of purchase and installation.

SUMMARY OF THE INVENTION

In accordance with the foregoing objects, the present invention—a secondary drive system for an air conditioner compressor—generally comprises a substantially conventional air conditioning circuit having integrated therewith a secondary compressor drive. In the preferred embodiment of the present invention, the secondary compressor drive includes an air motor for selectively operating the otherwise conventional compressor of the air conditioning circuit and a compressed fluid source for driving the air motor. The compressed fluid source includes a pressure vessel and a collection reservoir. Heat generated in the operation of the air conditioning circuit is utilized to convert a liquid phase of the operating fluid into a highly compressed gas within the pressure vessel whereafter the resulting compressed gas is utilized to drive the air motor. The air motor in turn operates the compressor of the otherwise conventional air conditioning circuit. After passage through the air motor, the operating fluid is captured within the collection reservoir as a gaseous or vaporous operating fluid for reuse in the system of the present invention.

Finally, many other features, objects and advantages of the present invention will be apparent to those of ordinary skill in the relevant arts, especially in light of the foregoing discussions and the following drawings, exemplary detailed description and appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Although those of ordinary skill in the art will readily recognize many alternative embodiments, especially in light of the illustrations provided herein, this detailed description is exemplary of the preferred embodiment of the present invention, the scope of which is limited only by the claims appended hereto.

As particularly shown inFIG. 1, the air conditioner drive system10of the present invention generally comprises a substantially conventional air conditioning circuit11having integrated therewith a secondary compressor drive40. In the preferred embodiment of the present invention, the secondary compressor drive40includes an air motor41for selectively operating the otherwise conventional compressor12of the air conditioning circuit11and a compressed fluid source60for driving the air motor41. As will be better understood further herein, the compressed fluid source60includes a pressure vessel19and a collection reservoir32. As also will be better understood further herein, heat generated in the operation of the air conditioning circuit11is utilized to convert a liquid phase30of the operating fluid24into a highly compressed gas25within the pressure vessel19, whereafter the resulting compressed gas25is utilized to drive the air motor41which in turn operates the compressor12of the otherwise conventional air conditioning circuit11. After passage through the air motor41, the operating fluid24is captured within the collection reservoir32as a gaseous or vaporous operating fluid33for reuse in the system of the present invention.

Referring still toFIG. 1in particular, the pressure vessel19of the preferred embodiment of the present invention is shown to contain the condenser coil20for the otherwise conventional air conditioning circuit11. Preferably, the condenser coil20is located in the lower portion of the pressure vessel19such that the condenser coil20is generally submerged within the liquid phase30of the operating fluid24, which may comprise any highly compressible gas such as commonly employed in air conditioning systems. Because, as will be apparent to those of ordinary skill in the art, the conventional operation of the compressor12of the air conditioning circuit11will heat the liquid phase30of the operating fluid24as the operating fluid of the air conditioning circuit11passes through the condenser coil20, it is to be expected that the operating fluid24will be heated from its liquid phase30into a highly compressed gas25within the pressure vessel19. In order to obtain this desired effect, however, it should also be recognized that the condenser coil20must be suspended within the pressure vessel19between a hermetically sealed conduit21into the interior of the vessel19and a hermetically sealed conduit22out of the vessel19.

As also particularly shown inFIG. 1, the collection reservoir32generally comprises a simple tank, which is preferably significantly larger in size than the pressure vessel19in order to collect the operating fluid24after passage through the air motor41without impeding operating of the air motor41. As will be appreciated by those of ordinary skill in the art, especially in light of this exemplary description, the collection reservoir32need not have the structural integrity of the pressure vessel19as the collection reservoir32will serve only to recapture the gaseous or vaporous operating fluid33from the air motor41, allow the operating fluid33to cool into a liquid operating fluid35and store the liquid operating fluid35until such time as it may be transferred back into the pressure vessel19. As shown in the figure, the collection reservoir32preferably comprises in inlet34to the top of the reservoir32for receiving the operating fluid24from the air motor41and an outlet36from the bottom of the reservoir32for return of the operating fluid24to the pressure vessel19. A transfer channel37, which may simply comprise a pipe or the like, interconnects the outlet36from the collection reservoir32to an inlet31provided in the lower portion of the pressure vessel19. As will be better understood further herein, a transfer pump38, which may comprise a simple centrifugal pump or the like, is preferably provided in the transfer channel37for pumping the liquid operating fluid35from the collection reservoir32to replenish the liquid phase30of the operating fluid24within the pressure vessel19. While those of ordinary skill in the art will recognize that other means for transfer may be implemented, such as, for example, gravity feed systems or the like, it is in any case critical that a check valve39or the like be provided within the transfer channel37to prevent backflow from the pressure vessel19to the collection reservoir32.

As in shown inFIGS. 1 and 2, the compressor12of the air conditioner drive system10is operably connected to the air motor41through an interposed clutch46. As will be appreciated by those of ordinary skill in art, any of a variety of clutch mechanisms may be implemented to this end. For example, the clutch46may be implemented utilizing the well known clutch mechanism typically associated with automobile air conditioning systems. Likewise, the electric compressor motor16of the otherwise conventional air conditioning circuit11is operably connected to the compressor12though a second interposed clutch17, which may be of the same design as the clutch46for the air motor41. In operation of the air conditioner drive system10of the present invention, the clutches17,46are utilized to selectively engage and disengage the electric compressor motor16and the air motor41, respectively, thereby preventing interference with each other during operation of one or the other. As particularly shown inFIG. 2, the clutches17,46, as well as the other components of the air conditioner drive system10of the present invention, may be controlled with an electronic controller47, the implementation of which is within the ordinary skill in the art.

Referring now toFIG. 3in particular, but with reference toFIGS. 1 and 2as well, one exemplary method of operation of the air conditioner drive system10of the present invention is detailed. As shown inFIG. 3, operation of the system10will generally commence (step48) with an initialization and startup sequence under the control of the electronic controller47. During such a sequence, the clutches17,46and the electric compressor motor16are set such that the air motor41is disengaged from the compressor12while the electric compressor motor16is engaged with the compressor12. The electric compressor motor16then operates the compressor12to begin the flow of operating fluid from the outlet14of the compressor12into the high side of the air conditioning circuit11.

The highly pressurized, gaseous operating fluid flowing from the outlet14of the compressor12flows through a conventional channel15from the compressor12, through the hermetically sealed conduit21into the interior of the pressure vessel19and into the condenser coil20contained in the lower portion of the vessel19. As is conventional, the operating fluid of the air conditioning circuit11is converted by the condenser coil20into a highly compressed liquid in a process generating substantial heat energy. This heat energy is in turn conducted from the condenser coil20into the liquid phase30of the operating fluid24of the secondary compressor drive40. As the liquid phase30becomes heated, the operating fluid24is converted to a highly compressed gas25contained within the upper portion of the pressure vessel19. The pressure of the compressed gas25is monitored (step49) with a pressure sensor28, preferably contained, for ease of maintenance, within a pressure line27from a provided outlet26in the top of the pressure vessel19to the inlet42of the air motor41. In particular, the electronic controller47monitors (step50) the pressure of the compressed gas25to determine when sufficient pressure exists within the pressure vessel19to drive the air motor41with enough power to operate the compressor12of the air conditioning circuit11.

When the electronic controller47determines that the pressure of the compressed gas25within the pressure vessel19exceeds a predetermined threshold pressure, the electronic controller47orchestrates a sequence of events to selectively switch power of the compressor12from the electric compressor motor16to the air motor41. In particular, as shown inFIG. 3, the electronic controller47operates the clutch17of the electric compressor motor16to disengage the electric compressor motor16from the compressor12. The electronic controller47then powers off (step51) the electric compressor motor16to conserve electrical energy. A flow control valve29, interposed within the pressure line27from outlet26of the pressure vessel19to the inlet42of the air motor41is then opened (step52) by the electronic controller47, whereafter the electronic controller47operates (step53) the clutch46associated with the air motor41to engage the air motor41with the compressor12.

With the air motor41engaged to operate the compressor12of the air conditioning circuit11(and the electric compressor motor16disengaged), the air conditioning circuit11operates as usual so long as there remains within the pressure vessel19compressed gas25of sufficient pressure. To this end, the electronic controller47monitors (step54) the pressure of the compressed gas25within the pressure vessel19. During this period, the compressed gas phase25of the operating fluid24passes through the air motor41and out of the outlet43from the air motor41though an exhaust line44into the inlet34to the top of the collection reservoir32. With time, the operating fluid24will be largely displaced from the pressure vessel19to the collection reservoir32, resulting in the pressure measured by the pressure sensor28falling below a second predetermined threshold pressure. When the electronic controller47determines that the pressure of the compressed gas25within the pressure vessel19has fallen below the second predetermined threshold pressure, the electronic controller47orchestrates a sequence of events to selectively switch power of the compressor12from the air motor41back to the electric compressor motor16as well as to transfer (step57) the liquid operating fluid35collected within the collection reservoir32back to the pressure vessel19.

In particular, the electronic controller47operates (step55) the clutch46associated with the air motor41to disengage the air motor41from the compressor12. The electronic controller47then closes (step56) the flow control valve interposed within the pressure line27between the pressure vessel19and the air motor41. At this time, the transfer cycle for returning operating fluid24to the pressure vessel19may be initiated (step57), utilizing the transfer pump38as necessary. The electronic controller47then powers on (step58) the electric compressor motor16and operates (steps59) the clutch17associated with electric compressor motor16to again engage the electric compressor motor16with the compressor12. The air conditioning circuit11then operates conventionally until such time as the controller47again determines that the pressure of the compressed gas25within the pressure vessel19exceeds the first predetermined threshold pressure (step49repeated).

While the foregoing description is exemplary of the preferred embodiment of the present invention, those of ordinary skill in the relevant arts will recognize the many variations, alterations, modifications, substitutions and the like as are readily possible, especially in light of this description, the accompanying drawings and claims drawn thereto. For example, those of ordinary skill in the art will recognize that the otherwise conventional air conditioning circuit11must be provided with a variety of conventional components such as, for example, a channel23interconnecting the condenser coil20with a provided evaporator18as well as control and other components not described herein but within the ready grasp of those of ordinary skill in the art.

Likewise, those of ordinary skill in the art will recognize the desirability or necessity for the inclusion of check valves and the like to ensure correct direction of fluid flow through the system10under all operating conditions. For example, Applicant has found it desirable to include a check valve45in the exhaust line44leading from the outlet43of the air motor41to the inlet34to the top of the collection reservoir32, thereby preventing backflow from the collection reservoir32to the air motor41. In any case, because the scope of the present invention is much broader than any particular embodiment, the foregoing detailed description should not be construed as a limitation of the scope of the present invention, which is limited only by the claims appended hereto.