Absorption heat-transfer system

• US 20050022963A1
• Filed: 11/29/2002
• Published: 02/03/2005
• Est. Priority Date: 11/30/2001
• Status: Active Grant

• Current Assignee: Cooling Technologies, Inc.
• Original Assignee: Cooling Technologies, Inc.
• Inventors: Klintworth, Michael W. II, Garrabrant, Michael A., Stout, Roger E., Collet, Eric
• Granted Patent: US 7,441,589 B2
• Time in Patent Office: Days
• US Class Current: 165/58
• CPC Class Codes: F25B 15/04 the refrigerant being ammonia evaporated from aqueous solution F25B15/025 takes precedence
• CPC Class Codes: F25B 2333/003 the generator or boiler is heated by combustion gas
• CPC Class Codes: F25B 2333/007 the generator or boiler heated by heat exchangers with steam or hot water as heating fluid or by a secondary boiling-condensing heater
• CPC Class Codes: F25B 2400/0411 for the expansion valve or capillary tube
• CPC Class Codes: F25B 27/02 using waste heat, e.g. from internal-combustion engines
• CPC Class Codes: F25B 29/006 of the sorption type system
• CPC Class Codes: F25B 41/28 specially adapted for sorption cycles
• CPC Class Codes: F25B 41/31 Expansion valves
• CPC Class Codes: Y02A 30/274 using waste energy, e.g. from internal combustion engine
• CPC Class Codes: Y02B 30/625 combined with heat or power generation [CHP], e.g. trigeneration
• CPC Class Codes: Y02P 80/15 On-site combined power, heat or cool generation or distribution, e.g. combined heat and power [CHP] supply

Abstract

A waste heat source (100) is used to heat a high temperature heat transfer fluid which is used to heat an absorption heat transfer machine (10) having a generator (20), an absorber (30), a condenser (40), and an evaporator (50) operatively connected together. The high temperature heat transfer fluid can also be used to heat a load (190) such as a room space or a process. The waste heat source (100) can also be used to heat an intermediate heat transfer fluid, which can be used to heat a second load (175) such as a space, a process, or an absorption heat transfer machine. Novel flow control devices (70, 60) for controlling the flow of weak solution from generator (20) to absorber (30) or of refrigerant from condenser (40) to evaporator (50), respectively, are also described.

Claims

1. An absorption, heat-transfer system comprising:

a) a first absorption heat-transfer machine comprising a first generator, an absorber, a condenser, and an evaporator operatively connected together;

b) said generator and said absorber having a first flow control device located therebetween and controlling the flow of a weak solution from said generator to said absorber;

c) said condenser and said evaporator having a second flow control device located therebetween and controlling the flow of a refrigerant from said condenser to said evaporator;

d) a waste-heat source passing a waste heat stream to a high-temperature heat exchanger for heating;

1) a solution pair in said first generator to a temperature of at least about 250°

F. (121°

C.) by means of a heat exchange unit in said generator and operationally connected to a high-temperature heat-exchange loop comprising a pump and a second heat exchange unit in said heat exchanger for heating a high-temperature heat-transfer fluid with said waste heat stream from said waste-heat source; and

2) at least one of the following;

a) a heating load by means of a third heat-exchange unit operationally connected to said high-temperature heat-exchange loop;

b) an intermediate-temperature heat-exchange loop comprising an operationally connected pump, a fourth heat exchange unit in an intermediate temperature heat exchanger, and a fifth heat-exchange unit for heating a second load by means of said waste heat stream emerging from said high-temperature heat exchanger.

2. The absorption, heat-transfer system according to claim 1 wherein said solution pair in said first generator is heated to a temperature of at least about 300°

F. (149°

C.) by means of said heat exchange unit in said generator.

3. The absorption, heat-transfer system according to claim 1 wherein said solution pair in said first generator is heated to a temperature of at least about 350°

F. (177°

C.) by means of said heat exchange unit in said generator.

4. The absorption, heat-transfer system according to claim 1 wherein said solution pair in said generator is water and ammonia.

5. The absorption, heat-transfer system according to claim 1 further comprising a second heat source for heating said generator of said absorption, heat-transfer machine.

6. The absorption, heat-transfer system according to claim 1 further comprising a first line for passing at least a portion of said high-temperature heat transfer fluid to said heat exchange unit in said generator of said absorption heat-transfer machine and a second line for of passing at least a portion of said high-temperature heat-transfer fluid to said third heat exchange unit for heating said heating load.

7. The absorption, heat-transfer system according to claim 6 wherein said high-temperature heat transfer fluid is passed to said heat exchange unit in said first generator and to said third heat exchange unit by means of a three-way valve.

8. The absorption, heat-transfer system according to claim 1 further comprising a thermal storage tank for storing said high-temperature heat-transfer fluid after heating by said waste-heat stream.

9. The absorption, heat-transfer system according to claim 1 wherein said high-temperature heat-transfer fluid is heated by said waste-heat stream in said high-temperature heat-exchanger by means of a line connected to said waste heat source, said line having a high-temperature heat-exchanger by-pass line.

10. The absorption, heat-transfer system according to claim 1 wherein said intermediate-temperature heat-transfer fluid is heated by said waste-heat stream in said intermediate-temperature heat-exchanger by means of a line connected to said high-temperature heat-exchanger, said line having an intermediate-temperature heat-exchanger by-pass line.

11. The absorption, heat-transfer system according to claim 1 with said waste-heat stream heating an intermediate-temperature heat-transfer fluid in said intermediate-temperature heat exchanger;

said intermediate heat-transfer fluid heating said second load with said second load comprising at least one of the following;

i) a space;

ii) a processing bad; and

iii) a second absorption heat-transfer machine.

12. The absorption, heat-transfer system according to claim 11 with said intermediate heat-transfer fluid heating said space.

13. The absorption, heat transfer system according to claim 11 with said intermediate heat-transfer fluid heating said processing load.

14. The absorption, heat-transfer system according to claim 11 with said intermediate heat-transfer fluid heating said second absorption heat-transfer machine.

15. The absorption, heat-transfer system according to claim 1 with said first flow control device comprising:

a) a first restrictor receiving said weak solution from a first line connected to said generator and passing said weak solution to said absorber with a second line;

b) a second restrictor located in said first line between said generator and said first restrictor;

c) a weak solution, by-pass line around said first restrictor comprising an on-off flow device.

16. The absorption, heat-transfer system according to claim 15 wherein said on-off flow device is operated by a controller.

17. The absorption, heat-transfer system according to claim 16 wherein said controller is connected to an absorption cycle sensor.

18. The absorption, heat-transfer system according to claim 1 with said first flow control device comprising:

a) a fixed restrictor receiving said weak solution from a first line connected to said generator and passing said weak solution to said absorber with a second line;

b) a variable restrictor positioned in said first line between said generator and said first fixed restrictor.

19. The absorption, heat-transfer system according to claim 18 with said variable restrictor comprising:

1) a housing having a cylindrical bore formed therein for receiving said weak solution at a first end and outputting said weak solution at a second end;

2) a cylindrical piston with a first end and second end;

a) moveably mounted in said cylindrical bore and having a common longitudinal axis therewith;

b) having a bore formed therein to pass said weak solution from said first end to said second end; and

c) having a valve stem at said second end;

said valve stem moveably engaging an orifice in said second end of said housing; and

3) a helical spring positioned around said valve stem and contacting said second end of said piston at one end and a shoulder of said housing at a second end.

20. The absorption, heat-transfer system according to claim 1 with said second flow control device comprising:

a) a thermal expansion valve receiving said refrigerant from a first line connected to said condenser and passing said refrigerant to said evaporator with a second line; and

b) a fixed restrictor located in said first line between said condenser and said thermal expansion valve to reduce the inlet pressure to said thermal expansion valve.

21. The absorption, heat-transfer system according to claim 1 with said second flow control device comprising:

a) a thermal expansion valve receiving said refrigerant from a first line connected to said condenser and passing said refrigerant to said evaporator with a second line; and

b) a refrigerant, by-pass line around said thermal expansion valve comprising a fixed restrictor for passing a fix amount of refrigerant from said condenser to said evaporator.

22. A weak-solution flow control device for an first absorption heat-transfer machine comprising a generator, an absorber, a condenser, and an evaporator operatively connected together, said flow control device comprising:

a) a first restrictor receiving said weak solution from a first line connected to said generator and passing said weak solution to said absorber with a second line;

b) a second restrictor located in said first line between said generator and said first restrictor;

c) a weak solution, by-pass line around said second restrictor, said by-pass line connected at one end to said first line upstream of said second restrictor and at a second end to said first line downstream of said second restrictor and upstream of said first restrictor and comprising an on-off flow device.

23. The absorption, heat-transfer system according to claim 22 wherein said on-off flow device is operated by a controller.

24. The absorption, heat-transfer system according to claim 23 wherein said controller is connected to at least one absorption cycle sensor.

25. A weak-solution flow control device for an first absorption heat-transfer machine comprising a generator, an absorber, a condenser, and an evaporator operatively connected together, said flow control device comprising:

a) a fixed restrictor receiving said weak solution from a first line connected to said generator and passing said weak solution to said absorber with a second line;

b) a variable restrictor positioned in said first line between said generator and said first fixed restrictor.

26. The absorption, heat-transfer system according to claim 25 with said variable restrictor comprising:

1) a housing having a cylindrical bore formed therein for receiving said weak solution at a first end and outputting said weak solution at a second end;

2) a cylindrical piston with a first end and second end;

a) moveably mounted in said cylindrical bore and having a common longitudinal axis therewith;

b) having a bore formed therein to pass said weak solution from said first end to said second end; and

c) having a valve stem at said second end;

said valve stem moveably engaging an orifice in said second end of said housing;

3) a helical spring positioned around said valve stem and contacting said second end of said piston at one end and a shoulder of said housing at a second end.

27. A refrigerant flow control device for a first absorption heat-transfer machine comprising a generator, an absorber, a condenser, and an evaporator operatively connected together, said flow control device comprising:

a) a thermal expansion valve receiving said refrigerant from a first line connected to said condenser and passing said refrigerant to said evaporator with a second line; and

b) a fixed restrictor located in said first fine between said condenser and said thermal expansion valve to reduce the inlet pressure to said thermal expansion valve.

28. A refrigerant flow control device for a first absorption heat-transfer machine comprising a generator, an absorber, a condenser, and an evaporator operatively connected together, said flow control device comprising:

a) a thermal expansion valve receiving said refrigerant from a first line connected to said condenser and passing said refrigerant to said evaporator with a second line; and

b) a refrigerant, by-pass line around said thermal expansion valve comprising a fixed restrictor for passing a fix amount of refrigerant from said condenser to said evaporator.