Pulse combustion system for a water heater

Abstract

A water heater. The water heater includes a water circuit adapted to conduct water to be heated, a combustion system operable to produce products of combustion and operable to provide the products of combustion to heat water in the water circuit, and a fuel train assembly configured to provide fuel to the combustion system. The fuel train assembly includes a gas expansion chamber, a first gas shut-off valve positioned upstream of the expansion chamber, and a second gas shut-off valve positioned downstream of the expansion chamber.

1 . A water heater comprising:
 a water circuit adapted to conduct water to be heated;   a combustion system operable to produce products of combustion and operable to provide the products of combustion to heat water in the water circuit; and   a fuel train assembly configured to provide fuel to the combustion system, the fuel train assembly comprising:
 a gas expansion chamber; 
 a first gas shut-off valve positioned upstream of the expansion chamber; and 
 a second gas shut-off valve positioned downstream of the expansion chamber. 
   
     
     
         2 . The water heater of  claim 1  wherein the combustion system is a pulse combustion system creating pressure pulses. 
     
     
         3 . The water heater of  claim 1  wherein the first gas shut-off valve and second gas shut-off valve substantially simultaneously adjust between an open position, in which fuel flows through both valves, and a closed position, in which fuel does not flow through either valve. 
     
     
         4 . The water heater of  claim 1 , the fuel train assembly further comprising a gas flapper valve positioned downstream of the gas expansion chamber and configured to permit substantially one-way flow of fuel in a downstream direction. 
     
     
         5 . The water heater of  claim 1 , the fuel train assembly further comprising a first supply line positioned upstream of the gas expansion chamber and supplying fuel to the gas expansion chamber and a second supply line supplying fuel from the gas expansion chamber to the combustion system. 
     
     
         6 . The water heater of  claim 1 , the fuel train assembly further comprising a regulator positioned upstream of the gas expansion chamber to control delivery pressure of fuel to the gas expansion chamber. 
     
     
         7 . A fuel delivery system for delivering fuel to a combustion system of a water heater tank assembly, the fuel delivery system comprising:
 a gas expansion chamber;   a first supply line supplying fuel to the gas expansion chamber;   a first gas shut-off valve positioned in the first supply line and upstream of the gas expansion chamber;   a second supply line supplying fuel from the gas expansion chamber to the combustion system; and   a second gas shut-off valve positioned in the second supply line and downstream of the gas expansion chamber.   
     
     
         8 . The fuel delivery system of  claim 7  wherein the combustion system is a pulse combustion system creating pressure pulses. 
     
     
         9 . The fuel delivery system of  claim 7 , further comprising a gas flapper valve positioned in the second supply line downstream of the gas expansion chamber. 
     
     
         10 . The fuel delivery system of  claim 7  wherein the first gas shut-off valve and second gas shut-off valve substantially simultaneously adjust between an open position, in which fuel flows through both valves, and a closed position, in which fuel does not flow through either valve. 
     
     
         11 . The fuel delivery system of  claim 7 , further comprising a regulator positioned in the first supply line upstream of the gas expansion chamber. 
     
     
         12 . A fuel train assembly for providing fuel to a combustion system, the fuel train assembly comprising:
 a gas expansion chamber;   a first gas shut-off valve positioned upstream of the gas expansion chamber to selectively interrupt flow of fuel into the gas expansion chamber; and   a second gas shut-off valve positioned downstream of the gas expansion chamber to selectively interrupt flow of fuel into the combustion system.   
     
     
         13 . The fuel train assembly of  claim 12  wherein the first gas shut-off valve and second gas shut-off valve substantially simultaneously adjust between an open position, in which fuel flows through both valves, and a closed position in which fuel does not flow through either valve. 
     
     
         14 . The fuel train assembly of  claim 12 , further comprising a gas flapper valve positioned downstream of the gas expansion chamber and configured to permit substantially one-way flow of fuel in a downstream direction. 
     
     
         15 . The fuel train assembly of  claim 12  wherein the combustion system is a pulse combustion system creating pressure pulses. 
     
     
         16 . The fuel train assembly of  claim 12 , further comprising a first supply line supplying fuel to the gas expansion chamber and a second supply line supplying fuel from the gas expansion chamber to the combustion system. 
     
     
         17 . The fuel train assembly of  claim 12 , further comprising a regulator positioned upstream of the gas expansion chamber and configured to control delivery pressure of fuel to the gas expansion chamber.