Apparatus and methods for increasing energy efficiency of pumped refrigerant cooling systems

Abstract

An economizer module for increasing energy efficiency of a pumped refrigerant cooling system is connected to a refrigerant pumping unit including a primary pump connected with heat extractor(s) via a primary circuit and a primary heat exchanger connected with a condensing unit via a secondary circuit. The economizer module includes a control panel with control software, a secondary heat exchanger connected with the heat extractor(s) via the primary circuit and with the primary heat exchanger, a cooler connected with the secondary heat exchanger via an economizer circuit, and a secondary pump connected between the cooler and the secondary heat exchanger. The control panel executes the control software to control fluid flow in the economizer circuit via the secondary pump so as to use ambient air to reject heat from working fluid being used to collect heat from refrigerant in said primary circuit before said heat travels to said secondary circuit.

What is claimed is: 
     
         1 . An economizer module couplable to a pumped refrigerant cooling system for increasing energy efficiency of the pumped refrigerant cooling system, wherein the pumped refrigerant cooling system comprises a refrigerant pumping unit, a condensing unit, and one or more heat extractor(s), wherein the refrigerant pumping unit includes a primary pump connected with the one or more heat extractor(s) via a primary circuit and a primary heat exchanger connected with the condensing unit via a secondary circuit, wherein the economizer module is coupled to the pumped refrigerant cooling system between the refrigerant pumping unit and a return of the one or more heat extractor(s) of the pumped refrigerant cooling system, the economizer module comprising:
 a control panel including a processor and a memory storing control software;   a secondary heat exchanger connected with the one or more heat extractor(s) via the primary circuit, and connected with a return of the primary heat exchanger of the refrigerant pumping unit;   a cooler connected with the secondary heat exchanger via an economizer circuit; and   a secondary pump connected between the cooler and the secondary heat exchanger in the economizer circuit,   wherein the processor of the control panel is configured to execute the control software to control fluid flow to and from the cooler in the economizer circuit via the secondary pump so as to use ambient air to reject heat from a working fluid being used to collect heat from refrigerant in the primary circuit before the heat travels to the secondary circuit.   
     
     
         2 . The economizer module of  claim 1 , wherein controlling the secondary pump associated with the economizer circuit so as to reject heat from the working fluid via the cooler reduces the heat load that would otherwise be mitigated by the condensing unit associated with the secondary circuit that is connected to the primary heat exchanger of the refrigerant pumping unit. 
     
     
         3 . The economizer module of  claim 1 , wherein the economizer module utilizes a dry cooler as the cooler associated with the economizer circuit, wherein the dry cooler includes a condenser coil coupled with fans to draw the ambient air across the condenser coil, and
 wherein the secondary pump is a water pump, and the economizer module utilizes a glycol and water mixture as the working fluid, which is pumped using the water pump according to the control software.   
     
     
         4 . The economizer module of  claim 3 , wherein the economizer module utilizes the dry cooler with the water pump to deliver the cooled glycol and water mixture to the secondary heat exchanger. 
     
     
         5 . The economizer module of  claim 4 , wherein the secondary heat exchanger of the economizer module is located inside the refrigerant pumping unit, where heat collected in the primary circuit can be transferred to the glycol and water mixture and then rejected back to outside air at the dry cooler. 
     
     
         6 . The economizer module of  claim 4 , wherein the secondary heat exchanger of the economizer module is located outside the refrigerant pumping unit, with insulated refrigerant lines connecting the secondary heat exchanger to the primary heat exchanger of the refrigerant pumping unit. 
     
     
         7 . The economizer module of  claim 1 , wherein the economizer module utilizes one of a dry cooler, an adiabatic chiller, or geothermal cooling as the cooler to reject collected heat from the secondary heat exchanger from the working fluid and then return cooled working fluid to the secondary heat exchanger. 
     
     
         8 . The economizer module of  claim 1 , wherein the economizer module further includes a check valve connected between the secondary heat exchanger and the cooler in the economizer circuit, and the processor of the control panel is configured to execute the control software to control the check valve to adjust the flow of working fluid to and from the cooler in the economizer circuit. 
     
     
         9 . The economizer module of  claim 1 , wherein the secondary heat exchanger of the economizer module is piped to a return connection of the primary heat exchanger of the refrigerant pumping unit. 
     
     
         10 . The economizer module of  claim 9 , wherein the economizer module further includes a refrigerant temperature sensor configured to measure return refrigerant temperature, and glycol and water mixture temperature sensors configured to measure supply and return glycol and water mixture temperatures to and from the cooler. 
     
     
         11 . The economizer module of  claim 10 , wherein the processor of the control panel is configured to execute the control software to evaluate performance and operation of the economizer module or economizer circuit based on the temperature measurements from the glycol and water mixture temperature sensors. 
     
     
         12 . The economizer module of  claim 11 , wherein the secondary pump of the economizer module is a variable speed water pump, and wherein the water pump speed is commanded by the control software in the control panel of the economizer module in order to increase or decrease a flow of a glycol and water mixture in the economizer circuit as needed to reduce a measured error between a target refrigerant temperature setpoint and a measured refrigerant temperature. 
     
     
         13 . The economizer module of  claim 11 , wherein the secondary pump of the economizer module is a fixed speed water pump, wherein the economizer module further includes at least one water control valve between the secondary heat exchanger and the cooler in the economizer circuit, and wherein the processor of the control panel is further configured to execute the control software to control the at least one water control valve so as to increase or decrease a flow of a glycol and water mixture in the economizer circuit as needed to reduce a measured error between a target refrigerant temperature setpoint and a measured refrigerant temperature. 
     
     
         14 . The economizer module of  claim 11 , wherein the cooler and the secondary pump of the economizer module provide sufficient water flow and capacity to service a plurality of refrigerant pumps including the refrigerant pumping unit and one or more additional refrigerant pumping units,
 wherein each individual refrigerant pumping unit further includes an electronically adjustable water control valve configured to control fluid flow to the refrigerant pumping unit, respectively, and   wherein the processor of the control panel is further configured to execute the control software to control the electronically adjustable water control valve of each individual refrigerant pump in order to increase or decrease a flow of a glycol and water mixture as needed to reduce a measured error between a target refrigerant temperature setpoint and a measured refrigerant temperature.   
     
     
         15 . The economizer module of  claim 14 , wherein the economizer module further includes one or more differential pressure regulators configured to control pressure and fluid flow for each individual refrigerant pumping unit, respectively. 
     
     
         16 . The economizer module of  claim 9 , which includes the secondary heat exchanger that provides pumped refrigerant cooling system economization, is modular and installable as an add-on device to existing, non-specific pumped refrigerant systems. 
     
     
         17 . The economizer module of  claim 16 , wherein the economizer module is installed at or vertically above the return connection of the primary heat exchanger in the refrigerant pumping unit, to allow for gravity to aid in the return and circulation of refrigerant. 
     
     
         18 . The economizer module of  claim 16 , wherein the economizer module is installed below the return connection of the primary heat exchanger in the refrigerant pumping unit, and wherein the economizer module further includes a device that is configured to aid in the return and circulation of refrigerant.