Heating system

Abstract

A heating system for heating a fluid, the system comprising two separate heat exchangers, each directly heated by a burner to heat the fluid, a common flue into which the two burners are arranged to discharge their exhaust gas, a common fan arranged to supply air to the two burners, and a gas supply to each burner. A splitter valve splits the air flow from the fan to the two burners. A controller controls the speed of the fan, the position of the splitter valve and the gas supplies according to the heat output requirement of the system.

1 . A heating system for heating a fluid, the system comprising:
 two separate heat exchangers, each directly heated by a burner to heat the fluid;   a common flue into which the two burners are arranged to discharge their exhaust gas;   a common fan arranged to supply air to the two burners;   a gas supply to each burner;   a splitter valve to split the air flow from the fan to the two burners; and   a controller to control the speed of the fan, the position of the splitter valve and the gas supplies according to the heat output requirement of the system.   
   
   
       2 . A system according to  claim 1 , wherein the splitter valve is continuously variable over a range of positions. 
   
   
       3 . A system according to  claim 2 , wherein there is a substantially linear relationship between the position of a valve element of the splitter valve and the ratio of fluid diverted to two streams. 
   
   
       4 . A system according to  claim 1 , wherein the splitter valve comprises an inlet; two outlets, one for each burner; an outer sleeve having two first outlet orifices, one for each stream; an inner element movably retained within the outer sleeve and having an inlet and two second outlet orifices, one for each stream; wherein the relative proportion of the inlet stream fed to each outlet is determined by the relative position of the inner element and outer sleeve. 
   
   
       5 . A system according to  claim 1 , wherein gas is supplied to each burner downstream of the splitter valve. 
   
   
       6 . A system according to  claim 1 , comprising more than two separate heat exchangers, each being heated by a burner.