WO1996035085A1

WO1996035085A1 - Heating and cooling system

Info

Publication number: WO1996035085A1
Application number: PCT/US1995/005564
Authority: WO
Inventors: Donald L. Sarver
Original assignee: Sarver Donald L
Priority date: 1995-05-04
Filing date: 1995-05-04
Publication date: 1996-11-07
Also published as: AU2469395A

Abstract

A closed air cycle system (80) for heating and cooling the interior (82) of a structure is provided. The air cycle system (80) includes compressors (12) to compress and to heat the air. A valve system is provided that is movable between a first heating position wherein a heat exchange (64) is effected between the compressed air and a register system (101), and a second cooling position wherein a heat exchange is effected between the partially decompressed air and the air outside (89) the structure. After the initial heat exchange, a third heat exchanger (260) intakes the compressed air. The third heat exchanger (260) is also coupled to the input end of a compressor (12) to provide air to the compressors. The third heat exchanger (260) effects a heat exchange between the compressed air and the air provided to the compressors. After exiting the third heat exchanger (260), the compressed air rotates turbine (39) to generate power to partially power the compressors.

Description

HEATING AND COOLING SYSTEM

Background of the Invention

This invention relates to heat pumps, and in particular, to a closed air cycle system for heating and cooling the interior of a structure.

Heat pumps have long been known in the art. While most present day heat pumps use freon, an environmentally unfriendly composition, early theories regarding the heat pump contemplated the use of air in a closed system. In an air cycle heat pump, an electric motor drives an air compressor which in turn is connected to a turbine. Air is taken into the compressor and compressed such that the air increases in temperature and pressure. To heat the interior of a structure, the air is passed through a heat exchanger to effect a heat exchange between the compressed air and the room to be heated. While the compressed air loses some of its heat in the exchange, the compressed air remains warm and maintains its pressure. The warm air is passed through a turbine such that the air is expanded and hence cooled substantially; and partially decompressed. The energy generated by the turbine may be used to partially operate the electric motor of the compressor. The cooled expanded air then passes through a heat exchanger to effect a heat exchange between the cool air and the warmer outside air to partially re-heat the expanded air. The expanded air is taken back into the compressor where the cycle is repeated.

To cool the interior of a structure, the heated, compressed air is passed through a heat exchanger to effect a heat exchange between the compressed air and the cooler outside air. In this manner, a portion of the heat is dissipated. The warm, compressed air is then passed through the turbine where it is expanded and cooled. The cool, expanded air is passed through a second heat exchanger to effect a heat exchange between the cool, expanded air and the air within the interior of the structure, thereby cooling the interior.

While the closed air cycle heat pump system is functional, the system is inefficient. During the heating cycle, the compressor takes in the very cool air that has just passed through the second heat exchanger. As a result, the compressor must do considerable work to compress the air to a temperature that can heat the interior of a structure. Similarly, during the cooling cycle, the compressor must do considerable work to compress the very cool air to a sufficient pressure and temperature to effect the heat exchange between the compressed air and the air outside the structure.

It is therefore a primary object and feature of this invention to provide a closed air cycle system for heating and cooling the interior of a structure that is highly efficient and economical.

It is a further object and feature of this invention to provide a closed air cycle system for heating and cooling the interior of a structure that is environmentally friendly.

It is a still further object and feature of this invention to provide a closed air cycle system for heating and cooling the interior of a structure that is easy to install and cost effective.

Summary Of The Invention In accordance with the invention, a closed air cycle system for heating and cooling the interior of a structure is provided. The system includes a plurality of compressors to compress and to heat the air cycled within the system. The compressors are run by an electrical motor. A first heat exchanger is coupled to an outlet end of the first compressor to intake the warm compressed air. A second heat exchanger is coupled to an outlet end of the second compressor to intake the warm compressed air. A first, second, third and fourth valves are interconnected to the first and second heat exchangers. When the closed air cycle is in the heating cycle, the first, second, third, fourth, fifth and sixth valves are positioned such that the first and second heat exchangers effect the heat exchange between the warm, compressed air and a heating system. When the closed air cycle system is in the cooling cycle, the first, second, third, fourth, fifth and sixth valves are positioned so that the first and second heat exchangers effect the heat exchange between the compressed air and the air outside of the structure.

A third heat exchanger is coupled to the outlet end of the first and second heat exchanger to intake the compressed air. In addition, the third heat exchanger is coupled to the input end of the compressor to provide the air to be compressed. The third heat exchanger effects a heat exchange between the compressed air and the partially decompressed air to be provided to the compressors. As a result, the air provided to the compressors is warmed before entering the compressors such that the compressors do less work to compress the air than required in previous closed, air cycle heat pumps. The system is thereby more efficient than previous closed, air cycle heat pumps.

A turbine is interconnected to the third heat exchanger to intake the compressed air. The energy of the compressed air rotates the turbine and generates energy to partially power the compressors. The air, now partially decompressed and hence cooled, passes through a fourth heat exchanger that is coupled to the input of the third heat exchanger, and the partially decompressed air is provided to the compressor. A fifth heat exchanger is interconnected to the third heat exchanger.

During the heating cycle, the third and fourth valves are positioned such that the fourth heat exchanger effects the heat exchange between the cool, partially decompressed air and the air outside the structure to partially re-warm the partially decompressed air before the air re-enters the third heat exchanger. During the cooling cycle, the first, second, third, fourth, fifth and sixth valves are positioned such that the fifth heat exchanger effects the heat exchange between the cool, partially decompressed air and the interior of the structure in order to cool the interior via the water in the water line, or air in an air line. To increase efficiency, a heat jacket may be placed over the compressors to recover part of the waste heat from the electric motor and compressors. In addition, a defrost system may be provided for melting any accumulation of frost in the third and fourth heat exchangers. The third and fourth heat exchangers may be coupled to a sewer system to allow the melted frost to drain.

Brief Description Of The Drawings

The drawings illustrate the best mode presently contemplated for carrying out the invention.

In the drawings:

Fig. 1 is a block diagram of a closed air cycle system for heating the interior of a structure in accordance with the present invention;

Fig.2 is a block diagram of a closed air cycle system for heating and cooling the interior of a structure in accordance with the present invention;

Detailed Description Of The Preferred Embodiment A closed air cycle system, Fig. 1, for heating the interior of a structure is generally designated by the reference numeral 80. The system 80 is defined by a first interior section 82 within the structure and a second exterior section 89 outside the structure. The interior section 82 includes a housing 15 for a compressor 12 driven by an electric motor 14. The compressor 12 takes in air from line 51 through an input 52 in housing 15. A heat jacket 17 may be placed around compressor 12 and motor 14 to prevent heat from dissipating. A heat jacket 202 may be placed around compressor 19 to prevent heat from dissipating. An input 22 of a first heat exchanger 64 is coupled by line 25 to outlet 26 of housing 15 to receive warm, compressed air from compressor 12.

The compressed air flows through first heat exchanger 64 and exits the heat exchanger through outlet 27 and through the line 28. An input 29 of a second compressor 19 is coupled by line 28 to the output 26 of the first compressor 12. The compressed air flows through first heat exchanger 64 and out of the first heat exchanger 64 through outlet 27. The compressed air flows through line 28 and through an input 29 of a second compressor 19. The second compressor 19 increases the temperature and pressure of the compressed air. The compressed air exits the compressor 19 through outlet 58 and through the line 31. The compressed air flows through an input 32 of heat exchanger 61 and flows through heat exchanger 61.

The compressed air flows through an output 33 of heat exchanger 61. The compressed air flows through line 34 and through input 35. The compressed air flows through third heat exchanger 260 and exits the heat exchanger 260 through outlet 36.

The interior section 82 of the closed air cycle system 80 includes a reaction turbine 39 and a fourth heat exchanger 44. The turbine 39 has an input end 37 coupled by line 53 to the output 36 of the third exchanger 260 for receiving the compressed air. The energy of the compressed air rotates the reaction turbine 39 and generates power. Power shaft 38 interconnects the turbine 39 and the compressor 12 and compressor 19. The power generated by rotation of turbine 39 is used to partially power the compressor 12 and compressor 19.

As the compressed air rotates the turbine 39, the air loses its energy and is partially decompressed, and hence cooled. The cold, partially decompressed air flows out the turbine 39 and through the output 49 that is coupled by line 41 to the input 42 of the fourth heat exchanger 44. The fourth heat exchanger 44 includes an output 46 coupled by line 45 to a second input 48 on the third heat exchanger 260.

The partially decompressed air flows through a second output 56 in the third heat exchanger 260 and into line 51 where the air is again taken into input 52 of housing 15 and the cycle is repeated.

In heat exchanger 64 the compressed air will release heat but will not lose pressure, to the counter flow forced air in duct 101. The lower temperature compressed air will leave the heat exchanger 64 through output 27, through line 28 and through input 29. In compressor 19 the compressed air will be increased in temperature and pressure. At the higher temperature and pressure the compressed air will flow through outlet 58, through line 31 and enter the heat exchanger 61 through input 32.

In heat exchanger 61 the higher temperature compressed air will release heat to the forced air in duct 101, from the interior structure. The compressed air will flow out of heat exchanger 61 and through the output 33. The forced air from the interior of the structure in duct 101 will flow through heat exchanger 61 and absorb heat from the compressed air. The higher temperature forced air will leave the second heat exchanger 61 through the output 62, through the input 63, and enter the first heat exchanger 64.

A forced air system 101 is also provided. The forced air system 101 includes a duct system containing air from the heated rooms that flows out of a second output 45 in first heat exchanger 64 and through valve 50, valve 60, and line 101 where the forced air is put into the heated rooms. The forced air flows through line 101, through the valve 10 and re-enters the second heat exchanger 61. The cycle is then repeated. A fan 69 is provided to facilitate the flow of forced air through the duct system 101.

In operation, cool, partially decompressed inside air from line 51 is taken into the compressor 12 and compressed such that the air increases in temperature and in pressure. The warm, compressed air flows through line 25 into the input 22 of first heat exchanger 64. In first heat exchanger 64, a heat exchange is effected between the warm, compressed air and the forced air in air duct 101. The forced air, now warmed from the heat exchange with the compressed air, is forced by fan 69 from the output 45 of heat exchanger 64 and through valve 50 and valve 60. The forced air flows through a register within the interior of the structure to heat air within the interior of the structure.

To re-heat the air, the air of the interior of the structure is again passed through the heat exchanger 61, heat exchanger 64 and the cycle is repeated.

After the heat exchange with the forced air, the compressed air flows out of output 33 of heat exchanger 61, through line 34 and into the first input 35 of the third heat exchanger 260. The compressed air flows out of output 36 of the third heat exchanger 260 and into the input end 37 of turbine 39. As previously described, the turbine 39 is located inside the structure to be heated.

The compressed air passes through the turbine 39 and the energy of the air rotates the turbine 39 so that the air is expanded, and hence, cooled substantially. As is known, the temperature of the expanded air will be cooler than the air outside the structure. Rotation of the turbine generates energy to partially power the compressor 12 and compressor 19.

The expanded air leaves turbine 39 through outlet 49 and enters fourth heat exchanger 44. Fourth heat exchanger 44 effects a heat exchange between the very cold, expanded air and the air outside the structure to partially re-heat the expanded air. This partially re-heated air is provided to the third heat exchanger 260. The third heat exchanger 260 effects the heat exchanger between the warm, compressed air from the second heat exchanger 61 and the partially decompressed air received from fourth heat exchanger 44 to increase the temperature of the partially decompressed air. The partially decompressed air in line 51 is taken back into compressor 12 through input 52 and the cycle is repeated.

Because the partially decompressed air has been partially re-heated by the heat exchanges effectuated by the third 260 and the fourth 44 heat exchangers, the compressor 12 and compressor 19 have to do less work to compress the air to a pressure and temperature sufficient to heat the forced air in duct 101. Since the compressors do less work, the system 80 is more efficient and more economical to operate than previous heat pump systems.

Referring to Fig. 2, a closed air cycle system 110 is provided for cooling the interior of a structure. The system 110 is defined by a first interior section 11 and a second exterior section 13. The interior section 11 includes a housing 86 having a compressor 88. The interior section 11 includes a housing 103 having a compressor 104. Compressor 88 and compressor 104 are driven by an electric motor 90. The compressor 88 takes in air from line 133 through an input 134 in housing 86 to compress and to heat the air. The warm, compressed air flows from output 95 through line 96 to input 97 of a first heat exchanger 100 in line 96.

The first heat exchanger 100 and second heat exchanger 108 includes valve 10, valve 20, valve 30, valve 40, valve 50 and valve 60 movable between a first cooling position when the system is in the cooling cycle, and a second heating position when the system is in the heating cycle. When in the cooling cycle, the valve 10 and 50 are positioned such that the first heat exchanger 100 and second heat exchanger 108 effects a heat exchange between the warm, compressed air and the air outside the structure. When in the heating cycle, valve 10 and valve 50 are positioned such that the first heat exchanger 100 and the second heat exchanger 108 effects a heat exchange between the warm, compressed air and the forced air from the interior of the structure.

When in the cooling cycle, valve 10 and valve 50 are repositioned. The cooler ambient temperature air flows through duct 102, through valve 10. The cooler ambient temperature air enters the duct 101, flows through and absorbs heat from the heat exchanger 108, continues through duct 101. The warmer ambient temperature air flows through the heat exchanger 100 absorbing heat. The warmer ambient temperature air is still cooler than the warm compressed air, flows through the valve 50, flows through duct 103 and flows back into the atmosphere.

After flowing through heat exchanger 100 and heat exchanger 108, the warm, compressed air exits through outlet 109 into line 119. Input 111 of a third heat exchanger 112 receives the air from line 119. The air flows through the third heat exchanger 112 and is outputted at outlet 115.

The interior section of 11 of the closed air cycle system 110 includes a reaction turbine 113. The reaction turbine 113 has an input 114 coupled by line 116 to the output 115 of the third heat exchanger 112. The warm, compressed air rotates the reaction turbine 113 and generates power that is transmitted on power shaft 118 to partially power compressor 88 and compressor 104.

As the compressed air rotates the turbine 113, the air loses its energy and is partially decompressed and cooled. As is known, the temperature of the partially decompressed air will be cooler than the air outside the structure. When in the heating cycle, the cold partially decompressed air exits turbine 113 through output 120 through valve 30, and flows through line 122 to the input 124 of a fourth heat exchanger 126. The fourth heat exchanger 126 includes valve 30 and valve 40 movable between a first cooling position when the system is in the cooling cycle, and a second heating position when the system is in a heating cycle. When in the cooling cycle, the valve 30 and valve 40 are positioned such that the fifth heat exchanger 162 effects a heat exchange between the cold, partially decompressed air received at input 163 and the interior of the structure. When in the heating cycle, the valve 30 and 40 are positioned such that the fourth heat exchanger 126 effects a heat exchange between partially decompressed air received at input 124 and the air outside the structure.

After the air flows through fourth heat exchanger 126, the air exits the fourth heat exchanger 126 through output 128 and is transmitted along line 129 to a second input 131 in the third heat exchanger 112. The partial decompressed air flows through the third heat exchanger 112 and output 132 into line 133. The air in line 133 is taken back into the compressor 88, compressor 104, and the cycle is repeated.

The first interior section 11 of the system 110 also includes a defrost system (not pictured).

When the system is in the cooling cycle, from turbine 113, the cooled, expanded air enters the fifth heat exchanger 162. The fifth heat exchanger effectuates a heat exchange between the interior of the structure and the cool, expanded air via the forced air in the forced air line 150. This, in turn, cools the interior of the structure.

However, when the system is in the heating cycle, the fourth heat exchanger 126 effectuates a heat exchange between the cool, expanded air and the air outside the structure. Since the temperature of the air outside the structure is higher than the temperature of the cooled, expanded air, the expanded air will increase in temperature.

The expanded air is then passed through the third heat exchanger 112. The third heat exchanger 112 effectuates a heat exchange between the warm, compressed air received at input 111 and the expanded air received at input 131 to partially re-heat the

^■ expanded air. This partially re-heated air is taken back into compressor 86 through line 133 and the cycle is repeated.

Because partial decompressed air has been partially re-heated by the heat exchange effectuated by the third 112 and the fourth 126 heat exchangers, the compressor 88 and compressor 104 has to do less work to compress the air. In heating cycle, the compressors do less work to compress the air to a pressure and a temperature sufficient to heat the forced air flowing in forced air duct 101. In the cooling cycle, the compressors have less work to do to compress the air to a pressure and a temperature to effect the heat exchange between the compressor air and the air outside the structure. As a result, the system 110 is more efficient and more economical to operate.

It can be seen through the description of this invention that various alternatives and embodiments are possible without deviating from the scope and spirit of this invention.

Claims

1. A closed air cycle system for heating air within a structure, comprising: a first compressor and second compressor to compress and to heat air; the increase in pressure and temperature of the compressed air in the compressors will be smaller compared to the present compressors; the coefficiency of performance will be higher; a first heat exchanger coupled to the first compressor so as to intake compressed air and effect a heat exchange between the compressed air and the air within a structure; a second heat exchanger coupled to the second compressor so as to intake compressed air and effect a heat exchange between the compressed air and the air within a structure; a third heat exchanger coupled to the first and second heat exchanger so as to intake the compressed air therefrom and coupled to the compressor so as to provide air to the compressor, the third heat exchanger effecting a heat exchange between the compressed air and the air provided to the compressors; a turbine coupled to the thirdt heat exchanger to intake the compressed air, the turbine rotating by energy of the compressed air so as to generate energy to partially power the compressors and partially decompress the compressed air; the decrease in pressure and temperature of the compressed air in the turbine will be smaller compared to the present turbines; and a fourth and fifth heat exchangers coupled to the turbine so as to intake the partially decompressed air and coupled to the third heat exchanger to provide the air for the compressors, the fourth heat exchanger effecting a heat exchange between the partially decompressed air and the air outside the structure.

2. The closed air cycle system of claim 1 further comprising an electric motor to partially power the compressors and a heat jacket placed over the compressor and the electric motor.

3. the closed air cycle system of claim 1 further comprising a heat jacket placed over the second compressor.

4. The closed air cycle system of claim 1 wherein the interior of the structure includes a register system coupled to the first heat exchanger and second heat exchanger effecting a heat exchange between the compressed air and the air within a structure.

5. A closed air cycle system for cooling the interior of a structure, comprising: a plurality of compressors to compress air; the increase in pressure and temperature of the compressed air in the compressors will be smaller compared to the present compressors; the coefficiency of performance will be higher; a fourth heat exchanger coupled to the turbine to intake the partially decompressed air and effect a heat exchange between the partially decompressed air and outside air; a third heat exchanger coupled to the second heat exchanger so as to intake the compressed air and coupled to the compressor to provide air to the compressor, the third heat exchanger effecting a heat exchange between the compressed air and the air provided to the compressor; a turbine coupled to the third heat exchanger to intake the compressed air, the turbine rotating by energy of the compressed air so as to generate energy to partially power the compressors and to partially decompress and cool the air; the decrease in pressure and temperature of the compressed air in the turbine will be smaller compared to the present turbines; and a fourth and fifth exchangers coupled to the turbine to intake the partially decompressed air and coupled to the third heat exchanger to provide the air for the compressors, the fifth heat exchanger effecting a heat exchange between the partially decompressed air and air within a structure.

6. The closed air cycle system of claim 4 further comprising an electric motor to partially power the compressor and a heat jacket .placed over the compressor and the electric motor.

7. The closed air cycle system of claim 4 further comprising a heat jacket placed over the second compressor.

8. A closed air cycle system for heating and cooling air within a structure, comprising: a plurality of compressors to compress air; the increase in pressure and temperature of the compressed air in the compressor will be smaller compared to the present compressors; the coefficiency of performance will be higher; a first heat exchanger coupled to the compressor to intake compressed air therefrom; a first, second, fifth and sixth valve interconnected to the first and second heat exchanger, the first, second, fifth and sixth movable between a first heating position wherein the first and second heat exchanger effects a heat exchange between the compressed air and the air within the structure and a second cooling position wherein the first and second heat exchanger effects a heat exchange between the compressed air and outside air; a third heat exchanger coupled to the second heat exchanger to intake the compressed air and coupled to the first compressor to provide air to the first compressor, the third heat exchanger effecting a heat exchange between the compressed air and the air provided to the compressors; a turbine coupled to the third heat exchanger to intake the compressed air, the turbine rotating by energy of the compressed air to generate energy to partially power the compressors and to partially decompress the compressed air; the decrease in pressure and temperature of the compressed air in the turbine will be smaller compared to the present turbines; and a fourth heat exchanger coupled to the turbine to intake the partially decompressed air and coupled to the third heat exchanger to provide the air for the compressors; a third and fourth valves interconnected to the fourth and fifth heat exchangers, the third and fourth valves movable between a first heating position wherein the fourth heat exchanger effects a heat exchange between the partially decompressed air and outside air and a second cooling position wherein the fifth heat exchanger effects a heat exchange between the partially decompressed air and the interior of the structure.

9. The closed air cycle system of claim 8 further comprising an electric motor to partially power the compressor and a heat jacket placed over the compressor and the electric motor.

10. The closed air cycle system of claim 8 wherein the interior of the structure includes a register system for effecting a heat exchange between the compressed air and air within the interior of the structure when the first, second, third, fourth, fifth and sixth valves are in the heating position.