Groundwater heat exchange system

Abstract

A groundwater heat exchange system for regulating a temperature of a loop fluid flow pumped through a closed loop fluid pathway for use by a heat pump includes one or more groundwater heat exchange units and a controller. Each groundwater heat exchange unit includes a heat exchanger and at least one groundwater pump. The heat exchanger is submersed in groundwater within a borehole and is configured to facilitate heat exchange between the groundwater and the loop fluid flow. Each groundwater pump has a plurality of non-zero flow rate settings corresponding to different non-zero flow rates at which the groundwater pump drives a flow of the groundwater through the heat exchanger. The controller is configured to adjust the flow rate settings of the at least one groundwater pump based on a heat exchange demand input.

1 . A groundwater heat exchange system for regulating a temperature of a loop fluid flow pumped through a closed loop fluid pathway for use by a heat pump, the system comprising:
 one or more groundwater heat exchange units, each groundwater heat exchange unit comprising:
 a heat exchanger submersed in groundwater within a borehole, and configured to facilitate heat exchange between the groundwater and the loop fluid flow; and 
 at least one groundwater pump each having a plurality of flow rate settings including a zero flow rate setting, in which the groundwater pump is in a deactivated state and does not drive a flow of the groundwater, and a plurality of non-zero flow rate settings corresponding to different non-zero flow rates at which the groundwater pump drives a flow of the groundwater through the heat exchanger; and 
   a controller configured to adjust the flow rate settings of the at least one groundwater pump based on a heat exchange demand input, which indicates any one of a plurality of states of demand for heat exchange between the groundwater and the loop fluid flow including no demand for heat exchange and a demand for increased heat exchange.   
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . The groundwater heat exchange system of  claim 1 , wherein:
 the at least one groundwater pump includes a first groundwater pump configured to drive a first flow of the groundwater through the groundwater heat exchanger and a second groundwater pump configured to drive a second flow of the groundwater through the heat exchanger; and   the controller adjusts the flow rate setting of the first groundwater pump and/or the flow rate setting of the second groundwater pump based on the heat exchange demand input by performing one of:
 adjusting the flow rate setting of the first groundwater pump and the flow rate setting of the second groundwater pump in parallel based on the heat demand input; and 
 adjusting the flow rate setting of the first groundwater pump and the flow rate setting of the second groundwater pump in a staggered manner based on the heat demand input. 
   
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . The groundwater heat exchange system of  claim 4 , wherein:
 the controller includes a first configuration, wherein:
 the controller transitions the first groundwater pump to one of the non-zero flow rate settings to increase a flow rate of the first flow to meet a demand for increased heat exchange indicated by the heat exchange demand input while the second groundwater pump is in the zero flow rate setting; and 
 when the first groundwater pump is operating at a maximum non-zero flow rate setting and the second groundwater pump is in the zero flow rate setting, the controller operates each of the first and second groundwater pumps in one of the non-zero flow rate settings in response to the heat exchange demand input indicating a demand for increased heat exchange; or 
   the controller includes a second configuration, wherein:
 when the heat exchange demand input transitions from indicating no demand for heat exchange to indicating a demand for increased heat exchange, the controller initially transitions the first groundwater pump from the zero flow rate setting to one of the non-zero flow rate settings while the second groundwater pump remains in the zero flow rate setting; and 
 subsequently, when the heat exchange demand input transitions from indicating no demand for heat exchange to indicating a demand for increased heat exchange, the controller initially transitions the second groundwater pump from the zero flow rate setting to one of the non-zero flow rate settings while the first groundwater pump remains in the zero flow rate setting. 
   
     
     
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         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . A method of controlling a groundwater heat exchange system for regulating a temperature of a loop fluid flow pumped through a closed loop fluid pathway for use by a heat pump, the groundwater heat exchange system comprising:
 a groundwater heat exchange unit comprising:
 a heat exchanger submersed in groundwater within a borehole, and configured to facilitate heat exchange between the groundwater and the loop fluid flow; and 
 at least one groundwater pump each having a plurality of flow rate settings including a zero flow rate setting, in which the groundwater pump is in a deactivated state and does not drive a flow of the groundwater, and a plurality of non-zero flow rate settings corresponding to different non-zero flow rates at which the groundwater pump drives a flow of the groundwater through the heat exchanger; and 
   a controller configured to adjust the flow rate settings of the at least one groundwater pump based on a heat exchange demand input, which indicates any one of a plurality of states of demand for heat exchange between the groundwater and the loop fluid flow including no demand for heat exchange and a demand for increased heat exchange,   
       the method comprising steps of:
 exchanging heat between the groundwater and the loop fluid flow using the heat exchanger; 
 adjusting the flow rate setting of one or more of the at least one groundwater pump based on a heat exchange demand input using the controller; and 
 repeating the exchanging and adjusting steps a limited number of times. 
 
     
     
         20 . The method of  claim 19 , wherein:
 the at least one groundwater pump includes a first groundwater pump; and   the adjusting step comprises adjusting the flow rate setting of the first groundwater pump to incrementally increase or decrease the flow rate of the corresponding flow of the groundwater based on the heat exchange demand input.   
     
     
         21 . The method of  claim 20 , wherein the adjusting step comprises delaying adjusting the flow rate setting of the first groundwater pump for a predetermined delay time based on a delay setting in response to a change in the heat exchange demand input received in the receiving step. 
     
     
         22 . The method of  claim 19 , wherein:
 the at least one groundwater pump includes a first groundwater pump configured to drive a first flow of the groundwater through the groundwater heat exchanger and a second groundwater pump configured to drive a second flow of the groundwater through the heat exchanger; and   the adjusting step comprises adjusting the flow rate setting of the first groundwater pump and/or the flow rate setting of the second groundwater pump based on the heat exchange demand input.   
     
     
         23 . The method of  claim 22 , wherein the adjusting step comprises adjusting the flow rate setting of the first groundwater pump and the flow rate setting of the second groundwater pump in parallel based on the heat demand input. 
     
     
         24 . The method of  claim 22 , wherein the adjusting step comprises adjusting the flow rate setting of the first groundwater pump and the flow rate setting of the second groundwater pump in a staggered manner based on the heat demand input. 
     
     
         25 . The method of  claim 24 , wherein:
 when the heat exchange demand input indicates a demand for increased heat exchange, the first groundwater pump is operating in a non-zero flow rate setting that is less than a maximum non-zero flow rate setting and the second groundwater pump is in the zero flow rate setting, the adjusting step comprises incrementally adjusting the first groundwater pump to one of the non-zero flow rate settings to increase the flow rate of the first flow while the second groundwater pump remains in the zero flow rate setting; and   when the heat exchange demand input indicates a demand for increased heat exchange, the first groundwater pump is operating in the maximum non-zero flow rate setting and the second groundwater pump is in the zero flow rate setting, the adjusting step comprises adjusting each of the first and second groundwater pumps to one of their non-zero flow rate settings.   
     
     
         26 . The method of  claim 24 , wherein in a series of the adjusting steps, the flow rate settings of the first and second groundwater pumps are adjusted on an alternative basis. 
     
     
         27 . The method of  claim 24 , wherein:
 the states of demand for heat exchange between the groundwater and the loop fluid flow indicated by the heat exchange demand input include a demand for decreased heat exchange; and   when the first and second groundwater pumps are each operating in one of their non-zero flow rate settings and the heat exchange demand input indicates a demand for decreased heat exchange, the adjusting step comprises operating the first groundwater pump in one of the non-zero flow rate settings and adjusting the flow rate setting of the second groundwater pump to the zero flow rate setting.   
     
     
         28 . The method of  claim 24 , wherein:
 the states of demand for heat exchange between the groundwater and the loop fluid flow indicated by the heat exchange demand input include a demand for decreased heat exchange; and   the first groundwater pump operates at a lower power than the second groundwater pump; and   when the second groundwater pump is operating at 50% of its maximum non-zero flow rate setting or less, the first groundwater pump is in the zero flow rate setting and the heat exchange demand input transitions to indicating a demand for decreased heat exchange, the adjusting step comprises adjusting the flow rate setting of the second groundwater pump to the zero flow rate setting and adjusting the flow rate setting of the first groundwater pump to its maximum non-zero flow rate setting.   
     
     
         29 . The method of  claim 24 , wherein:
 the first groundwater pump operates at a lower power than the second groundwater pump; and   when the first groundwater pump is operating at its maximum non-zero flow rate setting, the second groundwater pump is set to the zero flow rate setting, and the heat exchange demand input indicates a demand for increased heat exchange, the adjusting step comprises adjusting the flow rate setting of the first groundwater pump to the zero flow rate setting and adjusting the flow rate setting of the second groundwater pump to one of the non-zero flow rate settings.   
     
     
         30 . The method of  claim 22 , wherein the adjusting step comprises periodically adjusting each of the first and second groundwater pumps from the zero flow rate setting to one of their non-zero flow rate settings during periods when the heat exchange demand input indicates no demand for heat exchange. 
     
     
         31 . The method of  claim 19 , wherein the receiving step comprises:
 sensing a temperature of the loop fluid flow using a loop fluid temperature sensor; and   determining the heat exchange demand input based on a comparison of the sensed temperature of the loop fluid to a setpoint temperature.   
     
     
         32 . The method of  claim 31 , wherein:
 the loop fluid pathway includes a loop fluid supply pipe, through which the loop fluid flow is supplied to the heat pump from the heat exchanger, and a loop fluid return pipe, through which the loop fluid flow is returned to the heat exchanger; and   sensing the temperature of the loop fluid flow comprises sensing the temperature of the loop fluid flow in the supply pipe.   
     
     
         33 . The method of  claim 19 , wherein:
 the loop fluid pathway includes a loop fluid supply pipe, through which the loop fluid flow is supplied to the heat pump from the heat exchanger, and a loop fluid return pipe, through which the loop fluid flow is returned to the heat exchanger;   the system includes a bypass pipe connecting the loop fluid supply pipe to the loop fluid return pipe and a bypass valve configured to regulate a flow of the loop fluid between the loop fluid supply and return pipes through the bypass pipe; and   the method comprises adjusting the bypass valve based on the heat exchange demand input using the controller.   
     
     
         34 . (canceled) 
     
     
         35 . The method of  claim 19 , wherein:
 the system comprises a plurality of the groundwater heat exchange units including a first groundwater heat exchange unit and a second groundwater heat exchange unit;   the heat exchanger of the first groundwater heat exchange unit is positioned within a first borehole; and   the heat exchanger of the second groundwater heat exchange unit is positioned within a second borehole that is displaced from the first borehole.   
     
     
         36 . The method of  claim 35 , wherein:
 the system includes:
 valving configured to selectively circulate the loop fluid flow through one or both of the first and second groundwater heat exchange units; and 
 a flow rate sensor configured to detect a flow rate of the loop fluid flow upstream of the valving; 
   the method includes:
 detecting the flow rate of the loop fluid flow using the flow rate sensor; 
 comparing the detected flow rate to a threshold flow rate using the controller; 
 actuating the valving to circulate the loop fluid flow through the first groundwater heat exchange unit and to block the loop fluid flow from circulating through the second groundwater heat exchange unit using the controller when the flow rate of the loop fluid flow is below the threshold flow rate; and 
 actuating the valving to circulate the loop fluid flow through the first and second groundwater heat exchange units using the controller when the flow rate of the loop fluid flow is above the threshold flow rate.