Solar heating systems with integrated circulator control

Abstract

Solar heating systems are provided which transfer heat from a solar thermal energy source to a hot water heating system, e.g., a domestic hot water system or a radiant heating loop. These systems utilize a circulator pump with an integrated controller which provides solar differential temperature control, optimizing functioning of the solar heating system.

1 . A method of supplying heat to a solar heating system, the method comprising:
 (a) heating liquid using a solar heat source;   (b) delivering the heated liquid to a storage reservoir;   (c) circulating the heated liquid through the storage reservoir and back to the solar heating unit using a circulator pump;   (e) determining the temperature differential between the temperature of the liquid exiting the solar heating unit and the temperature of the liquid after it has exited the storage reservoir; and   (f) controlling circulation of the liquid based on the temperature differential, using a controller that is integrated with the circulator pump.   
   
   
       2 . The method of  claim 1  wherein the circulator pump and controller are integrated in a single, unitary fixture. 
   
   
       3 . The method of  claim 1  further comprising turning off operation of the pump when the temperature differential exceeds a predetermined setpoint. 
   
   
       4 . The method of  claim 1  further comprising turning off operation of the pump when the temperature in the reservoir exceeds a predetermined maximum. 
   
   
       5 . The method of  claim 1  further comprising turning off operation of the pump when the temperature at the exit of the solar heat source falls below a predetermined minimum. 
   
   
       6 . The method of  claim 4  further comprising activating a heat dump pump when the predetermined maximum is exceeded, and diverting liquid from the solar heat source to a heat dump. 
   
   
       7 . The method of  claim 1  wherein the system further includes a supplemental heat source, and the method further comprises activating a supplemental pump when the temperature at the exit of the solar heat source falls below a predetermined minimum, to deliver heated liquid through a supplemental loop from the supplemental heat source to the reservoir. 
   
   
       8 . A solar heating system comprising:
 (a) a solar heat source configured to heat a fluid;   (b) a reservoir for storage of the heated fluid   (c) a path for circulation of fluid from the solar heat source to the reservoir and back to the solar heat source;   (d) a pump configured to circulate fluid through the path; and   (e) a controller, integrated with the pump, configured to control the operation of the pump in response to variations in the temperature of the liquid in the storage reservoir.   
   
   
       9 . The heating system of  claim 8  further comprising a tank sensor configured to measure the temperature of liquid exiting the storage reservoir. 
   
   
       10 . The heating system of  claim 9  further comprising a source sensor configured to measure the temperature of liquid exiting the solar heat source. 
   
   
       11 . The heating system of  claim 10  wherein the controller is configured to calculate the temperature differential between the temperature measured by the tank sensor and the temperature measured by the collector sensor. 
   
   
       12 . The heating system of  claim 8  wherein the solar heat source comprises a solar collector. 
   
   
       13 . The system of  claim 8  wherein the storage reservoir comprises a direct fired water heater. 
   
   
       14 . The system of  claim 8  wherein the storage reservoir comprises a storage tank for a heating system. 
   
   
       15 . The system of  claim 8  further comprising a supplemental heat source, and a supplemental pump configured to deliver heated liquid from the supplemental heat source to the storage reservoir. 
   
   
       16 . The system of  claim 15  wherein the controller is configured to control operation of the supplemental pump.