Environmental control of liquid cooled electronics

Abstract

A method, system, and computer program product are provided for controlling liquid-cooled electronics, which includes measuring a first set point temperature, T a , wherein the T a is based on a dew point temperature, T dp of a computer room. A second set point temperature, T b , is measured, wherein the T b is based on a facility chilled liquid inlet temperature, T ci , and a rack power, P rack , of an electronics rack. A Modular Cooling Unit (MCU) set point temperature, T sp , is selected. The T sp is the higher value of said T a and said T b . Responsive to the selected T sp , a control valve is regulated. The control valve controls a flow of liquid that passes through a heat exchanger.

1 . A method for controlling liquid-cooled electronics, said method comprising:
 measuring a first set point temperature, T a , wherein said T a  is based on a dew point temperature, T dp  of a computer room;   measuring a second set point temperature, T b , wherein said T b  is based on a facility chilled liquid inlet temperature, T ci , and a rack power, P rack , of an electronics rack;   selecting a Modular Cooling Unit (MCU) set point temperature, T sp , wherein said T sp  is the higher value of said T a  and said T b ; and   regulating a control valve that controls a flow of liquid that passes through a heat exchanger, wherein said regulating is responsive to said selected T sp .   
     
     
         2 . The method of  claim 1 , said method further comprising:
 selecting a default value of said T sp , in response to determining said T a  and said T b  are not rationalized.   
     
     
         3 . The method of  claim 2 , said method further comprising:
 selecting said default value for T a  in response to determining said T dp  is not rationalized.   
     
     
         4 . The method of  claim 2 , said method further comprising:
 selecting said default value for T b  in response to determining said T ci  is not rationalized.   
     
     
         5 . The method of  claim 1 , wherein said T a  is set to a first temperature constant of 15 degrees Celsius if T dp  is less than a threshold temperature of 12 degrees Celsius, and wherein said T a  is set to a first sum of: said T dp  and a second temperature constant of 3 degrees Celsius if said T dp  is greater or equal to said threshold temperature. 
     
     
         6 . The method of  claim 1 , wherein said T b  is equal to a second sum of: said T ci , a product of 0.000032 and said P rack , and a third temperature constant of 1.4 degrees Celsius. 
     
     
         7 . The method of  claim 1 , said method further comprising:
 reducing a number of revolutions per minute (RPMs) of a liquid inlet pump of said MCU in response to a reduction in said T sp .   
     
     
         8 . The method of  claim 1 , wherein said T b  is equal to a second sum of: said T ci , a product of 0.000032 and said P rack , and a third temperature constant of 1.4 degrees Celsius.