solar water heating system

Abstract

The invention provides a system for providing heated domestic water. The system comprises a heating structure such as a solar collector and a tank connected by an upstream fluid path and a downstream fluid path. A control system is adapted to interrupt supply of water from a source to the system when the domestic water is delivered to a recipient. The invention further provides a heating system with a tank which is filled to a certain limit leaving a certain amount of free space, e.g. to adjust absorption of energy to a supplied amount of energy or for reserving space for drainage of the solar collector. The invention further relates to a solar collector which is protected against excessive temperatures. Furthermore, the intention provides a method for providing heated domestic water.

1 . A system for providing heated domestic water, said system comprising:
 a heating structure,   a tank,   an inlet for supply of water from a source,   an upstream fluid path communicating water from the tank to the heating structure,   a downstream fluid path communicating water from the heating structure to the tank,   an outlet for delivery of the domestic water to a recipient, and   a control system adapted to control supply of water from the source,   
     wherein the control system is adapted to interrupt supply of water from the source when the domestic water is delivered to a recipient. 
   
   
       2 . A system according to  claim 1 , wherein the control system comprises a valve movable between a closed configuration wherein it interrupts supply of the water and an opposite open configuration wherein it enables the supply of the water. 
   
   
       3 . A system according to  claim 2 , wherein the valve is located to open and close the inlet. 
   
   
       4 . A system according to any of the preceding claims, wherein the tank comprises a water-measuring device, which is adapted to measure a water content of the tank. 
   
   
       5 . A system according to  claim 4 , wherein the control system is adapted to interrupt supply of water from the source, when a specific percentage of the tank is filled with water. 
   
   
       6 . A system according to  claim 5 , wherein the control system is adapted to allocate an occupied portion of the tank for water and a free portion of the tank for auxiliary purpose. 
   
   
       7 . A system according to  claim 6 , wherein the allocation is based on a level of energy which is received from the heating structure. 
   
   
       8 . A system according to any of the preceding claims further comprising a circulation pump adapted to circulate the water in a loop formed by the fluid paths. 
   
   
       9 . A system according to  claim 8 , wherein the control system is adapted to stop the circulation pump, when the domestic water is delivered to the recipient. 
   
   
       10 . A system according to  claim 8 , wherein the circulation pump delivers the domestic water to the recipient. 
   
   
       11 . A system according to any of the preceding claims further comprising a temperature-measuring device, which is adapted to measure a temperature difference, ΔT, between the temperature of water which is contained in the heating structure and the temperature of the water in the tank. 
   
   
       12 . A system according to any of  claims 8 - 11 , wherein the control system is adapted to control the flow rate pumped by the circulation pump based on the temperature difference, ΔT. 
   
   
       13 . A system according to any of  claims 8 - 12 , wherein the temperature-measuring device is adapted to measure a temperature of the water in the tank, T tank , the control system being adapted to control the flow rate pumped by the circulation pump based on said temperature, T tank . 
   
   
       14 . A system according to any of the preceding claims further comprising a mixing chamber, which is adapted to open for supply of water from the source, when domestic water is delivered to a recipient, the water from the source being mixed with the water from the tank before delivering domestic water to the recipient. 
   
   
       15 . A system according to  claim 14  further comprising a thermostat, which is adapted to control mixing of the water from the source and the water from the tank to control the temperature of the domestic water delivered to the recipient. 
   
   
       16 . A system according to  claim 15 , wherein the thermostat is adapted to receive a temperature control input from the recipient and adapted to change the temperature of the domestic water according to said temperature control input. 
   
   
       17 . A system according to any of the preceding claims, wherein the tank comprises an auxiliary heater. 
   
   
       18 . A system according to  claim 17 , wherein the auxiliary heater is adapted to be deactivated, if the water content is below a predefined value. 
   
   
       19 . A system according to  claim 18 , wherein the control system is adapted to stop the auxiliary heater, when the temperature of the water in the tank, T tank , exceeds a predefined max value, T tank, max . 
   
   
       20 . A system according to any of the preceding claims further comprising a security device, which is adapted to interrupt electricity supply to the system, if the temperature of the water in the tank, T tank , exceeds a predefined security value, T security . 
   
   
       21 . A system according to  claim 20 , wherein the security device is adapted to connect the electricity to the system, when the temperature of the water in the tank, T tank , is below the predefined max value, T tank, max . 
   
   
       22 . A system according to any of the preceding claims, wherein the heating structure comprises a solar collector. 
   
   
       23 . A system according to  claim 22 , wherein the solar collector comprises a water reservoir, the system further comprising a drain device, said drain device being adapted to empty the solar collector upon receipt of a drain signal. 
   
   
       24 . A system according to  claim 23 , wherein the inlet is in fluid communication with the outlet via the tank, when the solar collector is drained. 
   
   
       25 . A system according to  claims 23 - 24 , wherein water which is drained from the solar collector is conducted into a free space of the tank. 
   
   
       26 . A system according to any of the preceding claims, further comprising an auxiliary upstream and a downstream fluid path communicating water between the system and an auxiliary heating system. 
   
   
       27 . A system according to any of the preceding claims, further comprising a weighing structure for determining a weight of the tank. 
   
   
       28 . A system according to  claim 27 , wherein the weight is determined for controlling a water content of the tank. 
   
   
       29 . A system for providing heated domestic water, said system comprising:
 a heating structure,   a tank,   an inlet for supply of water from a source,   an upstream fluid path communicating water from the tank to the heating structure,   a downstream fluid path communicating water from the heating structure to the tank,   an outlet for delivery of the domestic water to a recipient, and   a control system adapted to control supply of water from the source,   
     wherein the control system is adapted to fill a main portion of the tank with water and to reserve an auxiliary portion of the tank as a free space in the tank. 
   
   
       30 . A system according to  claim 29 , wherein the control system is adapted to release water which is contained in the heating structure upon detection of a precondition for the release. 
   
   
       31 . A system according to  claim 30 , wherein the precondition comprises reaching of a specific temperature level of water in the heating structure or reaching a specific temperature of the ambient atmosphere in which the heating structure is located. 
   
   
       32 . A system according to  claims 30 - 31 , wherein released water is conducted to the tank via the downstream fluid path. 
   
   
       33 . A system according to  claim 32 , wherein the released water occupies the free space of the tank when released there into. 
   
   
       34 . A system according to any of  claims 29 - 33 , comprising a weighing structure for providing a weight of the tank. 
   
   
       35 . A system according to  claim 34 , wherein a water content of the tank is determined based on the weight of the tank. 
   
   
       36 . A system for providing heated domestic water, said system comprising:
 a heating structure comprising a heating space for storage of water   a tank with a storage space for storage of water   an inlet for supply of water from a source,   an upstream fluid path communicating water from the tank to the heating structure,   a downstream fluid path communicating water from the heating structure to the tank, and   an outlet for delivery of the domestic water to a recipient, and   a release structure adapted to release water from the heating space upon detection of a precondition for the release.   
   
   
       37 . A method for providing heated domestic water from a system comprising a fluid reservoir, said reservoir comprising a heating structure and a tank connected by an upstream fluid path and a downstream fluid path, said method comprising the steps of:
 supplying water to the reservoir from a source,   circulating the water between the heating structure and the tank, and   interrupting supply of water from the source when the domestic water is delivered to a recipient.