Water Heating System and Valving for These

Abstract

A pump system for use with a solar collector system which is used to heat a heat transfer fluid, includes a storage tank and the pump system having a first and second pump arranged in parallel which can pump the heat transfer fluid from the storage tank to a solar collector, so that should one pump fail the other pump can function, wherein the outlet of the first pump and the outlet of the second pump are connected to a valve arrangement, whereby when the first pump operates the outlet of the second pump is substantially closed by the flow from the first pump and when the second pump operates the outlet of the first pump is substantially closed by the flow from the second pump.

1 . A pump system for use with a solar collector system which is used to heat a heat transfer fluid, said solar collector system including a storage tank for said heat transfer fluid used in said solar collector system, said pump system having a first and second pump arranged in parallel which can pump said heat transfer fluid from said storage tank to a solar collector, so that should one pump fail the other pump can function, wherein the outlet of said first pump and the outlet of said second pump are connected to a valve arrangement, whereby when said first pump operates the outlet of said second pump is substantially closed by the flow from said first pump and when said second pump operates the outlet of said first pump is substantially closed by the flow from said second pump. 
     
     
         2 . The pump system as claimed in  claim 1  wherein said valve arrangement has three ports and a valve member which effectively closes a first pump's outlet port when a second pump is operating and the first pump is not, and closes the second pump's outlet port when a first pump is operating and said second pump is not operating. 
     
     
         3 . The pump system as claimed in  claim 2 , wherein said three way valve arrangement has a flap which closes said first pump's outlet port and moves to a second location when activated by said first pump to close said second pump's outlet port. 
     
     
         4 . The pump system as claimed in  claim 2 , wherein said outlet ports are located on respective pipes which connect to said pumps. 
     
     
         5 . The pump system as claimed in  claim 1 , wherein said pump system is provided as part of a skid. 
     
     
         6 . A solar water heating system having the pump system as claimed in  claim 1  wherein said heat transfer fluid is not potable water. 
     
     
         7 . A solar water heating system having the pump system as claimed in  claim 1  wherein said heat transfer fluid is potable water. 
     
     
         8 . A valve for a pump system having two pumps and which will allow drain back of a pumped fluid, said valve including a body having first and second ports for respectively connecting to respective pump outlets or conduits from said outlets, and a third port, whereby when a pump is pumping said third port is an outlet from said body, and when said pumps are not pumping, said third port is an inlet to said body. 
     
     
         9 . The valve as claimed in  claim 8 , wherein between said first and second ports a valve member can move so as to close off one of said first or second ports depending upon which pump is operating. 
     
     
         10 . The valve as claimed in  claim 9 , wherein said valve member is a flap. 
     
     
         11 . The valve as claimed in  claim 10 , wherein said flap is hingedly connected to said body which allows movement of said flap between said first and said second ports. 
     
     
         12 . The valve as claimed in  claim 8  wherein said valve closes off said first or second ports to a substantial extent, that is watertight sealing is not required by the valve. 
     
     
         13 . The valve as claimed in  claim 10 , wherein said flap is manufactured from a metal, polymeric material or composite. 
     
     
         14 . The valve as claimed in  claim 10  wherein valve seats surrounding said first and second ports are manufactured from a metal, a polymeric or a composite material. 
     
     
         15 . The valve as claimed in  claim 8 , wherein surrounding said first port or said second port or said third port is one of the following: a male thread, a female thread. 
     
     
         16 . The valve as claimed in  claim 8  wherein surrounding a respective port is a female thread. 
     
     
         17 . The valve as claimed in  claim 10 , wherein said flap is held rotatable in said body, or pivotally held in said body, by means of opposed pins which seal to said body and pass into said body. 
     
     
         18 . A water heating system having a primary circuit to supply a heated heat transfer fluid to a heat exchanger, which supplies heat to a secondary circuit having potable water therein, wherein said primary circuit includes at least one pump to circulate said heat transfer fluid to and through said heat exchanger, and a control system to control the operation and output flow rate of said at least one pump, characterized in that said control system measures the temperature, or an indication of the temperature of said potable water after it has left said heat exchanger, so as to control the output flow rate of said at least one pump. 
     
     
         19 . The water heating system as claimed in  claim 18 , wherein said primary circuit heats the heat transfer fluid by one of or a combination of more than one of the following: solar;
 gas, electric, cogeneration means; gas boosted solar; electric boosted solar.   
     
     
         20 . The water heating system as claimed in  claim 18 , wherein said secondary circuit has one or more of the following: is a freshwater station system; is a district water heating system; includes a pump; includes a filter; includes a cold water supply; includes an over temperature shut down mechanism. 
     
     
         21 . The water heating system as claimed in  claim 18 , wherein said heat exchanger is provided in a delivery skid whereby there are two heat exchangers present on the skid, with respective isolation valves and having parallel connections to an incoming conduit and an outgoing conduit, whereby one of said heat exchangers is present in a redundancy capacity. 
     
     
         22 . The water heater system as claimed in  claim 21 , wherein said system can have multiple skids connected to each other to provide the heat exchanger of the system. 
     
     
         23 . A heat exchanger apparatus comprising a frame to support at least two heat exchangers, between an inlet conduit and an outlet conduit, wherein said at least two heat exchangers having connection to said inlet and outlet conduit in parallel, said connection being via isolation valves and forming a liquid supply inlet and heated liquid outlet, and each heat exchanger having fluid connection, via isolation valves, to a primary circuit to receive a heat transfer fluid to transfer heat to said liquid, characterized in that at least one of said heat exchangers is present in a redundant capacity. 
     
     
         24 . The heat exchanger apparatus as claimed in  claim 23 , wherein said inlet conduit and said outlet conduit have flanged ends to allow connection to an adjacent like heat exchanger apparatus, and or a conduit closure.