COOLING SYSTEMS AND METHODS INCORPORATING A PLURAL IN-SERIES PUMPED LIQUID REFRIGERANT TRIM EVAPORATOR CYCLE

• US 20150211769A1
• Filed: 04/09/2015
• Published: 07/30/2015
• Est. Priority Date: 10/09/2012
• Status: Active Grant

• Current Assignee: Inertech IP LLC
• Original Assignee: Inertech IP LLC
• Inventors: McDonnell, Gerald, Keisling, Earl
• Granted Patent: US 9,772,123 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F25B 23/006 boiling cooling systems
• CPC Class Codes: F25B 25/005 using primary and secondary systems
• CPC Class Codes: F25B 41/00 Fluid-circulation arrangements
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems
• CPC Class Codes: F25B 5/04 arranged in series
• CPC Class Codes: F25B 6/02 arranged in parallel
• CPC Class Codes: F25B 7/00 Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit F25B9/00 takes precedence

Abstract

The cooling systems and methods of the present disclosure relate to a plural in-series pumped liquid refrigerant trim evaporator cycle that may be incorporated into an existing cooling system to increase the efficiency of the existing cooling system. The cooling systems of the present disclosure include a first evaporator coil in thermal communication with an air intake flow to a heat load, such as a heat load being cooled by the existing cooling system, and a first liquid refrigerant distribution unit in thermal communication with the first evaporator coil. The cooling systems further includes a second evaporator coil disposed in series with the first evaporator coil in the air intake flow and in thermal communication with the air intake flow, and a second liquid refrigerant distribution unit in thermal communication with the second evaporator coil. A trim compression cycle of the second liquid refrigerant distribution unit is configured to incrementally further cool the air intake flow through the second evaporator coil when the temperature of the free-cooled first fluid flowing out of the main compressor of the second liquid refrigerant distribution unit exceeds a predetermined threshold temperature.

Claims

1. A cooling system comprising:

a first evaporator coil in thermal communication with an air intake flow to a heat load;

a first liquid refrigerant distribution unit in thermal communication with the first evaporator coil and a first fluid free-cooled by a fluid cooler;

a second evaporator coil disposed in series with the first evaporator coil in the air intake flow and in thermal communication with the air intake flow to the heat load;

a second liquid refrigerant distribution unit in thermal communication with the second evaporator coil and the first fluid free-cooled by the fluid cooler; and

wherein a trim compression cycle of the second liquid refrigerant distribution unit is configured to incrementally further cool the air intake flow through the second evaporator coil when the temperature of the free-cooled first fluid flowing out of the second liquid refrigerant distribution unit exceeds a predetermined temperature.

2. The cooling system according to claim 1, wherein the first evaporator coil is disposed downstream from the second evaporator coil in the air intake flow.

3. The cooling system according to claim 2, wherein the predetermined temperature is the maximum temperature needed to bring the temperature of the air intake flow out of the second evaporator down to a desired temperature.

4. The cooling system according to claim 1, wherein the first liquid refrigerant distribution unit includes:

a third evaporator in fluid communication with a fluid cooler and configured to enable the transfer of heat from the first fluid flowing from the fluid cooler to a second fluid;

a main condenser in fluid communication with the first and third evaporators and configured to enable the transfer of heat from a third fluid flowing from the first evaporator to the first fluid flowing from the third evaporator; and

a trim condenser in fluid communication with the main condenser and the third evaporator and configured to enable the transfer of heat from the second fluid flowing from the third evaporator to the first fluid flowing from the main condenser.

5. The cooling system according to claim 4, wherein the first liquid refrigerant distribution unit further includes:

a compressor in fluid communication with a fluid output of the third evaporator and a fluid input of the trim condenser; and

an expansion valve in fluid communication with a fluid output of the trim condenser and a fluid input of the third evaporator to form the trim compression cycle.

6. The cooling system according to claim 5, wherein the first liquid refrigerant distribution unit further includes:

a fluid receiver in fluid communication with a fluid output of the main condenser; and

a fluid pump in fluid communication with a fluid output of the fluid receiver and a fluid input of the first evaporator.

7. The cooling system according to claim 4, wherein the first fluid is water, the second fluid is a first refrigerant, and the third fluid is a second refrigerant.

8. The cooling system according to claim 1, wherein the second liquid refrigerant distribution unit includes:

a fourth evaporator in fluid communication with a fluid cooler and configured to enable the transfer of heat from the first fluid flowing from the fluid cooler to a fourth fluid;

a second main condenser in fluid communication with the second and fourth evaporators and configured to enable the transfer of heat from the fourth fluid flowing from the second evaporator to the first fluid flowing from the fourth evaporator; and

a second trim condenser in fluid communication with the main condenser and the fourth evaporator and configured to enable the transfer of heat from the fourth fluid flowing from the fourth evaporator to the first fluid flowing from the second main condenser.

9. The cooling system according to claim 8, wherein the first fluid is a water-based solution, the second fluid is a first refrigerant, and the fourth fluid is a second refrigerant.

10. The cooling system according to claim 8, wherein the second liquid refrigerant distribution unit further includes:

a second fluid receiver in fluid communication with an output of the second main condenser; and

a second fluid pump in fluid communication with a fluid output of the second fluid receiver and a fluid input of the second evaporator.

11. The cooling system according to claim 1, wherein the second liquid refrigerant distribution unit includes:

a third condenser in fluid communication with a fluid cooler and configured to enable the transfer of heat from the first fluid flowing from the fluid cooler to a fourth fluid flowing through the third condenser; and

a third evaporator in fluid communication with the third condenser and the second evaporator and configured to enable the transfer of heat from a fifth fluid flowing from the second evaporator to the fourth fluid flowing from the third condenser.

12. The cooling system according to claim 11, wherein the second liquid refrigerant distribution unit further includes:

an expansion valve in fluid communication with a fluid output of the third condenser and a fluid input of the third evaporator; and

a compressor in fluid communication with a fluid output of the third evaporator and a fluid input of the third condenser to form a second trim compression cycle.

13. The cooling system according to claim 11, wherein the second liquid refrigerant distribution unit further includes:

a fluid receiver in fluid communication with an fluid output of the third evaporator; and

a fluid pump in fluid communication with a fluid output of the fluid receiver and a fluid input of the second evaporator.

14. A method of operating a cooling system, comprising:

pumping a first refrigerant through a first evaporator coil in thermal communication with an air intake flow to a heat load;

pumping a free-cooled fluid through a first liquid refrigerant distribution unit in thermal communication with the first refrigerant flowing through the first evaporator coil;

pumping a second refrigerant through a second evaporator coil disposed in series with the first evaporator coil in thermal communication with the air intake flow downstream from the first evaporator coil;

pumping a free-cooled fluid through a second liquid refrigerant distribution unit in thermal communication with the second refrigerant flowing through the second evaporator coil;

determining whether the temperature of the free-cooled fluid flowing out of a condenser of the second liquid refrigerant distribution unit is greater than a predetermined temperature threshold; and

turning on a trim compression cycle of the second liquid refrigerant distribution unit if it is determined that the temperature of the free-cooled fluid flowing out of the condenser of the second liquid refrigerant distribution unit is greater than the predetermined temperature threshold.

15. The method according to claim 14, wherein the predetermined threshold temperature is determined based on the temperature of the free-cooled fluid flowing out of the condenser of the second liquid refrigerant distribution unit that cannot fully condense the second refrigerant back to a liquid.

16. The method according to claim 14, further comprising incrementally changing the heat load capacity of the trim compression cycle of the second liquid refrigerant distribution unit as outside environmental conditions change.

17. The method according to claim 14, further comprising incrementally increasing the heat load capacity of the trim compression cycle as the wet bulb temperature of the outside environment increases.

18. A cooling system comprising:

a first evaporator coil in thermal communication with an air intake flow to a heat load;

a first liquid refrigerant distribution unit in thermal communication with the first evaporator coil;

a second evaporator coil disposed in series with the first evaporator coil in the air intake flow and in thermal communication with the air intake flow to the heat load;

a second liquid refrigerant distribution unit in thermal communication with the second evaporator coil;

a fluid cooler for free cooling a first fluid; and

a fluid pump for circulating the first fluid through the first and second liquid refrigerant distribution units,

wherein a trim compression cycle of the second liquid refrigerant distribution unit is configured to incrementally further cool the air intake flow through the second evaporator coil when the temperature of the free-cooled first fluid flowing out of a condenser of the second liquid refrigerant distribution unit exceeds a predetermined temperature.