Electro-adsorption chiller: a miniaturized cooling cycle with applications from microelectronics to conventional air-conditioning

• US 6,434,955 B1
• Filed: 08/07/2001
• Issued: 08/20/2002
• Est. Priority Date: 08/07/2001
• Status: Expired due to Fees

• Current Assignee: National University of Singapore
• Original Assignee: National University of Singapore
• Inventors: Chakraborty, Anutosh, Gordon, Jeffrey M., Ng, Kim Choon, Chua, Hui Tong
• Primary Examiner(s): JIANG, CHEN WEN
• Application Number:
  US09/922,712
• Time in Patent Office: 378 Days
• Field of Search: 621/01, 621/06, 621/09, 624/80, 62/32, 62/33, 621/41, 621/42, 621/44
• US Class Current: 62/106
• CPC Class Codes: F25B 25/00 Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00

Abstract

A novel modular and miniature chiller is proposed that symbiotically combines absorption and thermoelectric cooling devices. The seemingly low efficiency of each cycle individually is overcome by an amalgamation with the other. This electro-adsorption chiller incorporates solely existing technologies. It can attain large cooling densities at high efficiency, yet is free of moving parts and comprises harmless materials. The governing physical processes are primarily surface rather than bulk effects, or involve electron rather than fluid flow. This insensitivity to scale creates promising applications in areas ranging from cooling personal computers and other micro-electronic appliances, to automotive and room air-conditioning.

Claims

1. An electro-adsorption chiller assembly comprising:

at least one condenser for cooling refrigerant;

at least one evaporator for cooling a location to be cooled, said at least one evaporator being connected to said at least one condenser by a pressure isolation device to provide a refrigerant circuit;

at least one pair of reactors connected to said at least one condenser and said at least one evaporator through at least one valve so as to provide a refrigerant circuit such that each reactor is capable of operating in adsorption and desorption modes;

at least one thermoelectric chiller, one of said at least one thermoelectric chiller being provided for each of said at least one pair of reactors, each of said at least one thermoelectric chiller having two junctions separately connected in a thermally conductive but electrically non-conductive manner, each of said at least one thermoelectric chiller being connected to a DC power source that is able to perform a voltage polarity switch so that each of said two junctions is capable of operating as a heating end and a cooling end, said DC power source being capable of supply varying power to each of said at least one thermoelectric chiller; and

a control device for controlling a process time interval, said pressure isolation device, the at least one valve between the at least one pair of reactors and said at least one condenser and said at least one evaporator, the voltage polarity of the DC power source, and the power supply by the DC power source to each of said at least one thermoelectric chiller, wherein one of said two junctions operates as a cooling end, one of said at least one pair of reactors attached to said cooling end being cooled down while it is isolated from said at least one condenser and said at least one evaporator and subsequently connected serially to said at least one evaporator to operate as an adsorber adsorbing vapour refrigerant from said at least one evaporator for a substantial period of time, and wherein a second of said two junctions simultaneously operates as a heating end, the other of said at least one pair of reactors attached to the heating end being heated up while it is isolated from said at least one condenser and said at least one evaporator and subsequently connected serially to said at least one condenser to operate as a desorber desorbing vapour refrigerant to said at least one condenser for a substantially identical time interval.

2. The electro-adsorption chiller assembly according to claim 1, wherein said pressure isolation device is an on-off-pressure reducing valve operated by one of the group consisting of electromagnetic, pneumatic, hydraulic, and solid-state power.

3. The electro-adsorption chiller assembly according to claim 1, wherein said pressure isolation device is a flooded U-bend.

4. The electro-adsorption chiller assembly according to claim 1, wherein said pressure isolation device is operated by one of the group consisting of electromagnetic, pneumatic, hydraulic, and solid-state power, said chiller assembly further comprising at least one serially connected hermetic or semi-hermetic pump for spraying refrigerant onto a heat exchanger surface of said at least one evaporator.

5. The electro-adsorption chiller assembly according to claim 1, wherein said pressure isolation device is operated by one of the group consisting of electromagnetic, pneumatic, hydraulic, and solid-state power, said chiller assembly further comprising at least one serially connected hermetic or semi-hermetic pump for distributing the refrigerant onto a heat exchanger surface of said at least one evaporator with a jet-impingement technique.

6. The electro-adsorption chiller assembly according to claim 1, wherein said pressure isolation device is a flooded U-bend, said chiller assembly further comprising at least one serially connected pump for spraying refrigerant onto a heat exchanger surface of said at least one evaporator.

7. The electro-adsorption chiller assembly according to claim 1, wherein said pressure isolation device is a flooded U-bend, said chiller assembly further comprising at least one serially connected pump for distributing the refrigerant onto a heat exchanger surface of said at least one evaporator with a jet impingement technique.

8. The electro-adsorption chiller assembly according to claim 1, wherein said at least one valve is a spool valve operated by one of the group consisting of electromagnetic or pieozoelectric, pneumatic, hydraulic, and solid-state power.

9. The electro-adsorption chiller assembly according to claim 1, wherein each of said reactors in each of said at least one pair of reactors comprises an adsorbent material sealed within a finned surface on one side and a mesh material on the other, said finned surface being located on a side of each of said reactors adjacent said at least one thermoelectric chiller, said mesh material being located on a side of each of said reactors remote from said at least one thermoelectric chiller.

10. The electro-adsorption chiller assembly according to claim 1, wherein there are a plurality of pairs of said reactors connected in parallel with each other to said at least one evaporator and said at least one condenser by a spool valve.

11. The electro-adsorption chiller assembly according to claim 1, wherein there are a plurality of pairs of said reactors connected in parallel with each other, each pair of said reactors is connected to the said at least one evaporator by at least one valve and separately connected to said at least one condenser by another at least one valve.

12. A method of cooling with an electro-adsorption chiller assembly, said method comprising the steps of:

providing at least one condenser for cooling refrigerant;

providing at least one evaporator for cooling a location to be cooled, said at least one evaporator being connected to said at least one condenser by a pressure isolation device to provide a refrigerant circuit;

providing at least one pair of reactors connected to said at least one condenser and said at least one evaporator through at least one valve so as to provide a refrigerant circuit such that each reactor is capable of operating in adsorption and desorption modes;

providing at least one thermoelectric chiller, one of said at least one thermoelectric chiller being provided for each of said at least one pair of reactors, each of said at least one thermoelectric chiller having two junctions separately connected in a thermally conductive but electrically non-conductive manner;

connecting each of said at least one thermoelectric chiller to a DC power source that is able to perform a voltage polarity switch so that each of said two junctions is capable of operating as a heating end and a cooling end, said DC power source being capable of supply varying power to each of said at least one thermoelectric chiller; and

providing a control device for controlling a process time interval, said pressure isolation device, the at least one valve between the at least one pair of reactors and said at least one condenser and said at least one evaporator, the voltage polarity of the DC power source, and the power supply by the DC power source to each of said at least one thermoelectric chiller;

operating one of said two junctions as a cooling end, one of said at least one pair of reactors attached to said cooling end being cooled down while it is isolated from said at least one condenser and said at least one evaporator and subsequently connected serially to said at least one evaporator to operate as an adsorber adsorbing vapour refrigerant from said at least one evaporator for a substantial period of time; and

simultaneously operating a second of said two junctions as a heating end, the other of said at least one pair of reactors attached to the heating end being heated up while it is isolated from said at least one condenser and said at least one evaporator and subsequently connected serially to said at least one condenser to operate as a desorber desorbing vapour refrigerant to said at least one condenser for a substantially identical time interval.

13. The method of cooling with an electro-adsorption chiller assembly according to claim 12, wherein said pressure isolation device is an on-off-pressure reducing valve, said method further comprising the step of operating said on-off pressure reducing valve by one of the group consisting of electromagnetic, pneumatic, hydraulic, and solid-state power.

14. The method of cooling with an electro-adsorption chiller assembly according to claim 12, wherein said pressure isolation device is a flooded U-bend.

15. The method of cooling with an electro-adsorption chiller assembly according to claim 12, further comprising the steps of:

operating said pressure isolation device by one of the group consisting of electromagnetic, pneumatic, hydraulic, and solid-state power;

serially connecting at least one pump; and

spraying refrigerant onto a heat exchanger surface of said at least one evaporator with said serially connected pump.

16. The method of cooling with an electro-adsorption chiller assembly according to claim 12, further comprising the steps of

operating said pressure isolation device by one of the group consisting of electromagnetic, pneumatic, hydraulic, and solid-state power;

serially connecting a pump; and

distributing the refrigerant onto a heat exchanger surface of said at least one evaporator with a jet-impingement technique.

17. The method of cooling with an electro-adsorption chiller assembly according to claim 12, wherein said pressure isolation device is a flooded U-bend, said method further comprising the steps of:

serially connecting at least one pump; and

spraying refrigerant onto a heat exchanger surface of said at least one evaporator with said serially connected pump.

18. The method of cooling with an electro-adsorption chiller assembly according to claim 12, wherein said pressure isolation device is a flooded U-bend, said method further comprising the steps of:

serially connecting at least one pump; and

distributing the refrigerant onto a heat exchanger surface of said at least one evaporator with a jet-impingement technique.

19. The method of cooling with an electro-adsorption chiller assembly according to claim 12, wherein said at least one valve is a spool valve, said method further comprising the step of operating said spool valve by one of the group consisting of electromagnetic or pieozoelectric, pneumatic, hydraulic, and solid-state power.