Condenser bypass for two-phase electronics cooling system

Abstract

An electronics cooling system utilizing a refrigerant fluid that evaporates to remove heat from electronics and is condensed back to liquid through heat exchange with a cold medium (air or water). The refrigerant fluid is circulated via a liquid pump between the condenser and heated evaporators. A bypass circuit is provided to divert flow around the condenser during conditions of cold ambient temperatures, which is controlled by a feedback loop using a mechanical or electronic control valve. This prevents the refrigerant fluid temperature from becoming very low and potentially inducing condensation on the outside of the refrigerant tubing from the warm and moist indoor air.

1 . A cooling system comprising:
 an evaporator, a pump, and a liquid receiver located in a first environment having a first ambient temperature;   a condenser located in a second environment having a second ambient temperature;   a refrigerant fluid circulated through the system by the pump by a primary fluid conduit to the evaporator, to the condensor, to the liquid receiver, and back to the pump; and   a valve adapted to selectively redirect fluid flow to bypass the condenser through a bypass fluid conduit located in the first environment.   
     
     
         2 . The cooling system of  claim 1 , wherein the valve is a pressure control valve. 
     
     
         3 . The cooling system of  claim 2 , wherein the pressure control valve has a predetermined pressure setpoint, the valve allowing fluid flow to the condenser when the pressure of the fluid entering the valve is greater than the pressure setpoint, the valve preventing fluid flow to the condenser and allowing fluid flow to bypass the condenser through a bypass fluid conduit located in the first environment when the pressure of the fluid entering the valve is less than the pressure setpoint. 
     
     
         4 . The cooling system as in  claim 1 , wherein the valve is located in the first environment downstream of the evaporator and upstream of the condenser. 
     
     
         5 . The cooling system as in  claim 1 , wherein the valve is located in the first environment downstream of the condenser and upstream of the liquid receiver. 
     
     
         6 . The cooling system as in  claim 1 , wherein the valve is an electronic control valve that is operated by a micro-processor controller in response to at least one of a pressure sensor or a temperature sensor. 
     
     
         7 . The cooling system as in  claim 1 , wherein the bypass fluid conduit is connected to the primary fluid conduit between the condenser and the liquid receiver. 
     
     
         8 . The cooling system of claim as in  claim 1 , wherein the bypass fluid conduit is directly connected to the liquid receiver. 
     
     
         9 . A cooling system comprising:
 an evaporator, a pump, and a liquid receiver located in a first environment having a first ambient temperature;   a condenser located in a second environment having a second ambient temperature;   a refrigerant fluid circulated through the system by the pump by a primary fluid conduit to the evaporator, to the condensor, to the liquid receiver, and back to the pump; and   a valve operable to redirect fluid flow from the evaporator to the liquid receiver through a bypass fluid conduit located in the first environment as needed in order to keep the fluid temperature within the first environment above a dew point of the first ambient temperature.   
     
     
         10 . The cooling system of  claim 9 , wherein the valve is a pressure control valve. 
     
     
         11 . The cooling system of  claim 10 , wherein the pressure control valve has a predetermined pressure setpoint, the valve allowing fluid flow to the condenser when the pressure of the fluid entering the valve is greater than the pressure setpoint, the valve preventing fluid flow to the condenser and allowing fluid flow to bypass the condenser through the bypass fluid conduit when the pressure of the fluid entering the valve is less than the pressure setpoint. 
     
     
         12 . The cooling system of  claim 10 , wherein the valve is located in the first environment downstream of the evaporator and upstream of the condenser. 
     
     
         13 . The cooling system of  claim 10 , wherein the valve is located in the first environment downstream of the condenser and upstream of the liquid receiver. 
     
     
         14 . The cooling system as in  claim 10 , wherein the valve is an electronic control valve that is operated by a micro-processor controller in response to at least one of a pressure sensor or a temperature sensor. 
     
     
         15 . The cooling system as in  claim 10 , wherein the bypass fluid conduit is connected to the primary fluid conduit between the condenser and the liquid receiver. 
     
     
         16 . The cooling system as in  claim 10 , wherein the bypass fluid conduit is directly connected to the liquid receiver. 
     
     
         17 . A cooling system comprising:
 an evaporator, a pump, and a liquid receiver located in a first environment having a first ambient temperature;   a condenser located in a second environment having a second ambient temperature;   a refrigerant fluid circulated through the system by the pump by a primary fluid conduit to the evaporator, to the condensor, to the liquid receiver, and back to the pump; and   a pressure control valve having a predetermined pressure setpoint, the valve allowing fluid flow to the condenser when the pressure of the fluid entering the valve is greater than the pressure setpoint, the valve preventing fluid flow to the condenser and allowing fluid flow to bypass the condenser through a bypass fluid conduit located in the first environment when the pressure of the fluid entering the valve is less than the pressure setpoint.   
     
     
         18 . The cooling system of  claim 17 , further comprising a pressure feedback conduit. 
     
     
         19 . The cooling system as in  claim 17 , wherein the valve is located in the first environment downstream of the evaporator and upstream of the condenser. 
     
     
         20 . The cooling system as in  claim 17 , wherein the valve is located in the first environment downstream of the condenser and upstream of the liquid receiver.