Thermosyphon coolers for cooling systems with cooling towers

Patent metadata

Field	Value
Publication number	US-2016348979-A1
Application number	US-201615231545-A
Country	US
Kind code	A1
Filing date	Aug 8, 2016
Priority date	May 27, 2010
Publication date	Dec 1, 2016
Grant date	—

Abstract

In one embodiment, a cooling system may include a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler may use natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler may be located in the cooling system upstream of, and in series with, the cooling tower, and may be operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, may be used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

First claim

1 . A cooling system, comprising:
a cooling fluid loop configured to cycle a cooling fluid therethrough; a dry heat rejection system disposed along the cooling fluid loop and configured to transfer heat from the cooling fluid to a refrigerant in an evaporator of the dry heat rejection system, wherein the dry heat rejection system is configured to transfer heat from the refrigerant to ambient atmosphere through dry cooling; a cooling tower disposed downstream of the dry heat rejection system along the cooling fluid loop and configured to transfer heat from the cooling fluid to the ambient atmosphere through evaporative cooling; a pressure sensor configured to measure a pressure of the refrigerant in the evaporator of the dry heat rejection system; a valve of the dry heat rejection system configured to block a flow of the refrigerant to the evaporator when in a closed position; and a controller configured to control operation of the dry heat rejection system based at least on measures of water cost, electricity cost, or a combination thereof, wherein the controller is configured to adjust a position of the valve of the dry heat rejection system based at least on the pressure of the refrigerant in the evaporator of the dry heat rejection system.

2 . The system of claim 1 , wherein the controller is configured to adjust the valve to the closed position when the pressure of the refrigerant in the evaporator is less than a first pressure threshold.

3 . The system of claim 2 , wherein the controller is configured to adjust a position of an additional valve disposed along the cooling fluid loop, such that the cooling fluid bypasses the dry heat rejection system when the pressure of the refrigerant in the evaporator is less than a second pressure threshold, wherein the second pressure threshold is less than the first pressure threshold.

4 . The system of claim 2 , wherein the controller is configured to deactivate operation of the dry heat rejection system when the pressure of the refrigerant in the evaporator is less than a second pressure threshold, wherein the second pressure threshold is less than the first pressure threshold.

5 . The system of claim 4 , wherein the evaporator of the dry heat rejection system comprises heat tracing, cartridge heaters, or both, and wherein the controller is configured to activate the heat tracing, the cartridge heaters, or both, when the pressure of the refrigerant in the evaporator is less than the second pressure threshold.

6 . The system of claim 5 , wherein the controller is configured to deactivate the heat tracing, the cartridge heaters, or both when the pressure of the refrigerant in the evaporator exceeds a third pressure threshold, and wherein the third pressure threshold is greater than the second pressure threshold and less than the first pressure threshold.

7 . The system of claim 6 , wherein the controller is configured to adjust the valve from the closed position to an open position when the pressure of the refrigerant in the evaporator exceeds a fourth pressure threshold, and wherein the fourth pressure threshold is greater than the third pressure threshold and the first pressure threshold.

8 . The system of claim 4 , wherein the dry heat rejection system comprises a drain valve, and wherein the controller is configured to open the drain valve when the pressure of the refrigerant in the evaporator falls below a third pressure threshold, wherein the third pressure threshold is less than the second pressure threshold.

9 . The system of claim 1 , wherein the controller is configured to determine a flow of the cooling fluid through the evaporator of the dry heat rejection system based on a pressure differential of the cooling fluid flowing through the evaporator of the dry heat rejection system, and wherein the controller is configured to initiate a low temperature protection mode when the flow of the cooling fluid through the dry heat rejection system is substantially zero and the pressure of the refrigerant in the evaporator is below a threshold.

10 . The system of claim 9 , wherein the controller activates heat tracing, cartridge heaters, or both in the evaporator in the low temperature protection mode.

11 . The system of claim 1 , comprising a temperature sensor configured to measure a temperature of the ambient atmosphere, wherein the temperature sensor is configured to provide feedback to the controller indicative of the temperature of the ambient atmosphere.

12 . The system of claim 11 , wherein the controller is configured to adjust the valve to the closed position when the temperature of the ambient atmosphere is below a threshold temperature.

13 . One or more tangible, non-transitory machine-readable media comprising processor-executable instructions to:
receive feedback from a pressure sensor configured to measure a pressure of a refrigerant in an evaporator of a dry heat rejection system, wherein the dry heat rejection system is configured to transfer heat from a cooling fluid to the refrigerant, and wherein the dry heat rejection system is disposed along a cooling fluid loop upstream of a cooling tower; compare the pressure of the refrigerant flowing through the evaporator of the dry heat rejection system to a first pressure threshold; and close a first valve of the dry heat rejection system to block the refrigerant of the dry heat rejection system from flowing to the evaporator when the pressure of the refrigerant in the evaporator of the dry heat rejection system is below the first pressure threshold.

14 . The one or more tangible, non-transitory machine-readable media of claim 13 , wherein the processor-executable instructions:
compare the pressure of the refrigerant in the evaporator of the dry heat rejection system to a second pressure threshold, wherein the second pressure threshold is less than the first pressure threshold; close a second valve of the cooling fluid loop to block the cooling fluid from flowing through the evaporator of the dry heat rejection system when the pressure of the refrigerant in the evaporator of the dry heat rejection system is below the second pressure threshold; and activate heat tracing, cartridge heaters, or both of the evaporator of the dry heat rejection system when the pressure of the refrigerant in the evaporator of the dry heat rejection system is below the second pressure threshold.

15 . The one or more tangible, non-transitory machine-readable media of claim 14 , wherein the second valve of the cooling fluid loop is configured to direct the cooling fluid to the cooling tower such that the cooling fluid bypasses the dry heat rejection system.

16 . The one or more tangible, non-transitory machine-readable media of claim 14 , wherein the processor-executable instructions:
deactivate the heat tracing, the cartridge heaters, or both when the pressure of the refrigerant in the evaporator of the dry heat rejection system exceeds a third pressure threshold, wherein the third pressure threshold is greater than the second pressure threshold and is less than the first pressure threshold; open the second valve of the cooling fluid loop to enable flowing of the cooling fluid to the evaporator of the dry heat rejection system when the pressure of the refrigerant in the evaporator of the dry heat rejection system exceeds the third pressure threshold; and open the first valve of the dry heat rejection system to enable flowing of the refrigerant to the evaporator when the pressure of the refrigerant in the evaporator of the dry heat rejection system exceeds a fourth pressure threshold, wherein the four

Assignees

• Johnson Controls Tech Co

Inventors

• Furlong James W
• Pillis Joseph W
• Lehman Delmar E

Classifications

• Y10T29/49359

  Cooling apparatus making, e.g., air conditioner, refrigerator · CPC title

• F28C2001/006

  Systems comprising cooling towers, e.g. for recooling a cooling medium · CPC title

• F28F27/003

  specially adapted for cooling towers · CPC title

• F28F27/02

  for controlling the distribution of heat-exchange media between different channels ({static flow control means in header boxes F28F9/026}; arrangements of guide plates or guide vanes F28F9/22, F28F25/12) · CPC title

• F28D15/0266

  with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers (F28D15/043 takes precedence) · CPC title