ENHANCED DEHUMIDIFICATION CONTROL WITH VARIABLE CONDENSER REHEAT

• US 20080098756A1
• Filed: 10/26/2006
• Published: 05/01/2008
• Est. Priority Date: 10/26/2006
• Status: Active Grant

• Current Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Original Assignee: Lennox Manufacturing Inc. (Lennox International Incorporated)
• Inventors: Uselton, Robert B.
• Granted Patent: US 9,347,676 B2
• Time in Patent Office: Days
• US Class Current: 62/173
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 11/81 by controlling the air supply to heat-exchangers or bypass channels
• CPC Class Codes: F24F 11/84 using valves
• CPC Class Codes: F24F 11/86 by controlling compressors within refrigeration or heat pump circuits
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2110/20 Humidity
• CPC Class Codes: F24F 2140/00 Control inputs relating to system states
• CPC Class Codes: F24F 3/153 with subsequent heating, i.e. with the air, given the required humidity in the central station, passing a heating element to achieve the required temperature

Abstract

An air conditioning system comprising an air mover for circulating air to a space; a vapor compression circuit including a compressor, a condenser, and an expansion device; an evaporator; an air-reheat heat exchanger; and a control system. In one embodiment, the evaporator receives refrigerant from the vapor compression circuit and provides a cooled stream of air to the space. The air-reheat heat exchanger is positioned to receive the cooled stream of air. In one embodiment, the vapor compression circuit, the evaporator, and the air-reheat heat exchanger are operable in combination to provide a plurality of modes of operation. In a preferred embodiment, the control system is configured to compute a Sensible cooling-to-Total cooling (S/T) process ratio and to control an operation of at least one of the vapor compression circuit, the evaporator, and the air-reheat heat exchanger. A method of manufacturing the air conditioning system is also provided.

Claims

1. An air conditioning system, comprising:

an air mover for circulating air to a space;

a vapor compression circuit including a compressor, a condenser, and an expansion device;

an evaporator for receiving refrigerant from said vapor compression circuit and adapted to provide a cooled stream of air to said space;

an air-reheat heat exchanger positioned to receive said cooled stream of air;

wherein said vapor compression circuit, said evaporator, and said air-reheat heat exchanger are operable in combination to provide a plurality of modes of operation; and

a control system configured to compute a Sensible cooling-to-Total cooling (S/T) process ratio and to control an operation of at least one of said vapor compression circuit, said evaporator, and said air-reheat heat exchanger.

2. The air conditioning system as recited in claim 1 wherein said control system is further configured to select an appropriate mode from said plurality based upon said S/T process ratio.

3. The air conditioning system as recited in claim 1 wherein said control system is further configured to:

receive a first input of a desired temperature and a desired humidity of said space; and

compute a desired absolute humidity ratio from said first input.

4. The air conditioning system as recited in claim 3 wherein said vapor compression circuit is sufficient to provide said cooled stream of air with an actual humidity corresponding to said desired humidity.

5. The air conditioning system as recited in claim 3 wherein said air-reheat heat exchanger is sufficient to provide said cooled stream of air with an actual temperature corresponding to said desired temperature.

6. The air conditioning system as recited in claim 3 wherein said control system is further configured to:

receive a second input of a current temperature and a current humidity conditions of said space; and

compute an indoor absolute humidity ratio from said second input.

7. The air conditioning system as recited in claim 6 wherein said control system is further configured to compute said process ratio from said desired absolute humidity ratio and said indoor absolute humidity ratio.

8. The air conditioning system as recited in claim 1 wherein each of said plurality comprises a configuration of:

said air mover;

said evaporator; and

said air-reheat heat exchanger, in combination.

9. The air conditioning system as recited in claim 3 wherein said control system is configured to prioritize said desired humidity over said desired temperature.

10. The air conditioning system as recited in claim 1 wherein said air-reheat heat exchanger is communicated with at least one of a liquid discharged from said condenser and a gas discharged from said compressor for reheating said cooled stream of air to a desired temperature for said space.

11. A method of manufacturing an air conditioning system, comprising:

providing an air mover for circulating air to a space;

providing a vapor compression circuit including a compressor, a condenser, and an expansion device;

providing an evaporator for receiving refrigerant from said vapor compression circuit and adapted to provide a cooled stream of air to said space;

positioning an air-reheat heat exchanger to receive said cooled stream of air;

configuring said vapor compression circuit, said evaporator, and said air-reheat heat exchanger to be operable in combination to provide a plurality of modes of operation; and

configuring a control system to compute a Sensible cooling-to-Total cooling (S/T) process ratio and to control an operation of at least one of said vapor compression circuit, said evaporator, and said air-reheat heat exchanger.

12. The method as recited in claim 11 wherein configuring a control system further comprises configuring a control system to select an appropriate mode from said plurality based upon said S/T process ratio.

13. The method as recited in claim 11 wherein configuring a control system further comprises configuring a control system to:

receive a first input of a desired temperature and a desired humidity of said space; and

compute a desired absolute humidity ratio from said first input.

14. The method as recited in claim 13 wherein providing a vapor compression circuit includes providing a vapor compression circuit sufficient to provide said cooled stream of air with an actual humidity corresponding to said desired humidity.

15. The method as recited in claim 13 wherein providing an air-reheat heat exchanger includes providing an air-reheat heat exchanger sufficient to provide said cooled stream of air with an actual temperature corresponding to said desired temperature.

16. The method as recited in claim 13 wherein configuring a control system further comprises configuring a control system to:

receive a second input of a current temperature and a current humidity conditions of said space; and

compute an indoor absolute humidity ratio from said second input.

17. The method as recited in claim 16 wherein configuring a control system further comprises configuring a control system to compute said process ratio from said desired absolute humidity ratio and said indoor absolute humidity ratio.

18. The method as recited in claim 11 wherein configuring said vapor compression circuit, said evaporator, and said air-reheat heat exchanger includes configuring said vapor compression circuit, said evaporator, and said air-reheat heat exchanger wherein each of said plurality comprises a configuration of:

said air mover;

said evaporator; and

said air-reheat heat exchanger, in combination.

19. The method as recited in claim 11 further comprising configuring said air-reheat heat exchanger to communicate liquid discharged from said condenser for reheating said cooled stream of air to a desired temperature for said space.

20. The method as recited in claim 11 further comprising configuring said air-reheat heat exchanger to communicate gas discharged from said compressor for reheating said cooled stream of air to a desired temperature for said space.