Thermosyphon coolers for cooling systems with cooling towers

Patent metadata

Field	Value
Publication number	US-2016348978-A1
Application number	US-201615231527-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 method for operating a cooling system, comprising:
determining a temperature of a cooling fluid exiting a dry heat rejection device; comparing the temperature of the cooling fluid exiting the dry heat rejection device to a cooling temperature set point; reducing a fan speed of one or more fans of the dry heat rejection device when the temperature of the cooling fluid exiting the dry heat rejection device is less than the cooling temperature set point; determining an economic efficiency of operation of the one or more fans of the dry heat rejection device based on a water cost, or an electricity cost, or both when the temperature of the cooling fluid exiting the dry heat rejection device equals or exceeds the cooling temperature set point; increasing the fan speed of the one or more fans of the dry heat rejection device when the economic efficiency of operation of the one or more fans of the dry heat rejection device exceeds a threshold and when the temperature of the cooling fluid exiting the dry heat rejection device equals or exceeds the cooling temperature set point; and reducing the fan speed of the one or more fans of the dry heat rejection device and initiating operation of a cooling tower when the economic efficiency of operation of the one or more fans of the dry heat rejection device is less than or equal to the threshold and when the temperature of the cooling fluid exiting the dry heat rejection device equals or exceeds the cooling temperature set point.

2 . The method of claim 1 , comprising maintaining the fan speed of the one or more fans of the dry heat rejection device when the temperature of the cooling fluid exiting the dry heat rejection device is generally equal to the cooling temperature set point and when the economic efficiency of operation of the one or more fans of the dry heat rejection device equals or exceeds the threshold.

3 . The method of claim 1 , wherein reducing the fan speed of the one or more fans of the dry heat rejection device when the temperature of the cooling fluid exiting the dry heat rejection device is less than the cooling temperature set point comprises turning off the one or more fans of the dry heat rejection device when the fan speed of the one or more fans of the dry heat rejection device is at a base speed.

4 . The method of claim 1 , wherein reducing the fan speed of the one or more fans of the dry heat rejection device when the economic efficiency of operation of the one or more fans of the dry heat rejection device is less than or equal to the threshold and when the temperature of the cooling fluid exiting the dry heat rejection device equals or exceeds the cooling temperature set point comprises reducing the fan speed of the one or more fans to a base fan speed.

5 . The method of claim 1 , wherein determining the economic efficiency of operation of the one or more fans of the dry heat rejection device based on a water cost, or an electricity cost, or both comprises calculating an economic power consumption of the dry heat rejection device.

6 . The method of claim 5 , wherein calculating the economic power consumption of the dry heat rejection device comprises dividing current kilowatts consumed by a motor of the one or more fans by a temperature differential between the temperature of the cooling fluid exiting the dry heat rejection device and an additional temperature of the cooling fluid exiting a process heat exchanger of the cooling system positioned upstream of the dry heat rejection device.

7 . The method of claim 6 , comprising determining a differential between an economic power consumption limit and the economic power consumption of the dry heat rejection device, wherein the economic power consumption limit is determined based on the water cost, or the electricity cost, or both.

8 . The method of claim 7 , comprising comparing the differential between the economic power consumption of the dry heat rejection device and the power consumption limit to the threshold.

9 . The method of claim 1 , wherein initiating operation of the cooling tower comprises increasing an additional fan speed of one or more additional fans of the cooling tower.

10 . One or more tangible, non-transitory machine-readable media comprising processor-executable instructions to:
receive feedback indicative of a temperature of a cooling fluid exiting a dry heat rejection device from a temperature sensor; compare the temperature of the cooling fluid exiting the dry heat rejection device to a cooling temperature set point; reduce a fan speed of one or more fans of the dry heat rejection device when the temperature of the cooling fluid exiting the dry heat rejection device is less than the cooling temperature set point; determine an economic efficiency of operation of the one or more fans of the dry heat rejection device based on a water cost, or an electricity cost, or both when the temperature of the cooling fluid exiting the dry heat rejection device equals or exceeds the cooling temperature set point; increase the fan speed of the one or more fans of the dry heat rejection device when the economic efficiency of operation of the one or more fans of the dry heat rejection device exceeds a threshold and when the temperature of the cooling fluid exiting the dry heat rejection device equals or exceeds the cooling temperature set point; and reduce the fan speed of the one or more fans of the dry heat rejection device and initiate operation of a cooling tower when the economic efficiency of operation of the one or more fans of the dry heat rejection device is less than or equal to the threshold and when the temperature of the cooling fluid exiting the dry heat rejection device equals exceeds the cooling temperature set point.

11 . The one or more tangible, non-transitory machine-readable media of claim 10 , wherein the processor-executable instructions are configured to monitor a change in the temperature of the cooling fluid exiting the dry heat rejection device over a set time.

12 . The one or more tangible, non-transitory machine-readable media of claim 11 , wherein the processor-executable instructions are configured to adjust the fan speed of the one or more fans of the dry heat rejection device when the change in the temperature of the cooling fluid exiting the dry heat rejection device exceeds an additional threshold over the set time.

13 . The one or more tangible, non-transitory machine-readable media of claim 10 , wherein the processor-executable instructions are configured to re-compare the temperature of the cooling fluid exiting the dry heat rejection device to the cooling temperature set point after adjusting the fan speed of the one or more fans of the dry heat rejection device.

14 . The one or more tangible, non-transitory machine-readable media of claim 10 , wherein the processor-executable instructions are configured to increase an additional fan speed of one or more additional fans of the cooling tower to initiate operation of the cooling tower when the economic efficiency of operation of the one or more fans of the dry heat rejection device is less than or equal to the threshold and when the temperature of the cooling fluid exiting the dry heat rejection device equals or exceeds the cooling temperature set point.

15 . A cooling system, comprising:
a cooling fluid loop configured to circulate a cooling fluid therethrough; a dry heat rejection device disposed along the cooling fluid loop and configured to transfer heat from the cooling fluid to ambient atmosphere through dry cooling; a cooling tower disposed downstream of the dry heat rejection device alo

Assignees

• Johnson Controls Tech Co

Inventors

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

Classifications

• F28D15/00

  Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls {; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies (F28D17/00, F28D19/00, F28D20/00 take precedence)} · CPC title

• F28D7/103

  consisting of more than two coaxial conduits or modules of more than two coaxial conduits · CPC title

• F28D15/025

  having non-capillary condensate return means · CPC title

• F28C1/00 Primary

  Direct-contact trickle coolers, e.g. cooling towers (building construction E04H5/12; enclosed spaces cooled by trickle F25; components parts of trickle coolers F28F25/00; {indirect-contact cooling towers F28B1/06}) · CPC title

• F28C2001/006

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