Control for Geothermal Heating System

Abstract

A geothermal energy transfer system has a heat transfer loop associated with a heat pump and a heat absorption loop to circulate fluid through an energy source, such as the ground or body of water. The loops are connected through a reservoir and each loop has a circulating pump to circulate fluid through respective loops. The flow rates of the pumps are selected to optimise energy transfer in each loops and differences in the flow rates are absorbed in the reservoir.

1 . A geothermal energy transfer system to transfer thermal energy between an energy source and an energy consumer, said system comprising a first loop to circulate heat transfer fluid through said source, a second loop to circulate heat transfer fluid through said consumer, a fluid reservoir connected to each of said loops to receive fluid from and deliver fluid to each of said loops, a first pump to circulate fluid in said first loop and a second pump to circulate fluid in said second loop. 
     
     
         2 . The system of  claim 1  wherein at least one of said pumps has a variable flow rate. 
     
     
         3 . The system of  claim 2  wherein both of said pumps have a variable flow rate. 
     
     
         4 . The system of  claim 2  including a controller to control the flow rate of said pumps. 
     
     
         5 . The system of  claim 4  wherein said controller controls a heat pump thermally connected to one of said loops and, said flow rates are coordinated with the operation of said heat pump. 
     
     
         6 . The system of  claim 1  wherein each of said loops has a supply and a return and the supply of one of said loops is connected to the return of the other said loops. 
     
     
         7 . The system of  claim 6  wherein said reservoir is connected between the supply and returns of each loop to accommodate differing flow rates therein. 
     
     
         8 . The system of  claim 7  wherein the supply and returns are connected to respective inlets and outlets of said reservoir. 
     
     
         9 . The system of  claim 8  wherein said reservoir has a pair of inlets and a pair of outlets and said pumps are connected to respective pairs of said inlets and outlets. 
     
     
         10 . The system of  claim 9  wherein an inlet connected to one of said loops is connected to an outlet connected to the other of said loops. 
     
     
         11 . The system of  claim 10  wherein each of said inlets and outlets is in communication with said reservoir. 
     
     
         12 . The system of  claim 1  wherein the flow rates of said first and second pumps are different and said reservoir accommodates the differential in flow. 
     
     
         13 . The system of  claim 12  wherein at least one of said first and second pumps is adjustable for flow rate. 
     
     
         14 . The system of  claim 13  wherein both of said pumps are adjustable for flow rate. 
     
     
         15 . The system of  claim 14  wherein operation of said first and second pumps is controlled by a controller. 
     
     
         16 . The system of  claim 15  wherein said controller adjusts said first and second pumps between a first condition in which both pumps have an intermediate flow rate and a second condition in which both pumps have a flow rate greater than said intermediate flow rate. 
     
     
         17 . The system of  claim 16  wherein said flow rates are maintained in a predetermined ratio in both said first and second conditions. 
     
     
         18 . The system of  claim 17  wherein said rates may be varied depending on the operational mode of said energy transfer system. 
     
     
         19 . A flow centre for use in a geothermal energy transfer system, said flow centre comprising a reservoir to contain fluid, a first inlet for connection to a return of one loop and a supply of another to receive a differential flow through said loops, and an outlet for connection to a supply of said one loop and a return of said other loop to supply fluid to make up for a difference in flows in said loops. 
     
     
         20 . A flow centre according to  claim 19  wherein a pair of tubes extend through said reservoir to permit connection at opposite ends of said respective supply and return, said tubes having an aperture therein to provide respective ones of inlet and said outlet. 
     
     
         21 . A flow centre according to  claim 19  wherein a pair of reservoirs are provided and a conduit is provided to transfer fluid between said reservoirs. 
     
     
         22 . A flow centre comprising a body defining a reservoir, a pair of tubes extending through said reservoir and having opposite ends for connection to respective pipes, and an aperture intermediate said ends to allow fluid communication between said tube and said reservoir. 
     
     
         23 . The flow centre to  claim 22  where said aperture is provided by a plurality of holes disposed about the circumference of said tube.