Hot water heater with self-powered automatic pilot light

Abstract

Hot water heater system (such as, for example, a gas-powered hot water heater system) that includes a self-powered automatic pilot light and which is not connected to any external source of electrical power.

What is claimed is: 
     
         1 . A water heating system comprising:
 a water tank;   a main burner configured to heat water in the water tank;   a pilot light configured to ignite fuel to light the main burner;   a first thermo-mechanical valve unit that monitors temperature of the water and determines whether the temperature of the water is below a first threshold, and permits fuel to flow to the pilot light, when the first thermo-mechanical valve unit determines that the temperature of the water is below the first threshold;   an ignition unit configured to ignite the pilot light, when the first thermo-mechanical valve unit permits fuel to flow to the pilot light; and   a second thermo-mechanical valve unit that monitors temperature near the pilot light and determines whether the pilot light is ignited, and permits fuel to flow to the main burner and be ignited by the pilot light, when the second thermo-mechanical valve unit determines that the temperature near the pilot light is above a second threshold.   
     
     
         2 . The water heating system of  claim 1 , wherein
 the first thermo-mechanical valve unit prevents fuel from flowing to the pilot light to thereby extinguish the pilot light, when the first thermo-mechanical valve unit determines that the temperature of the water is equal to or greater than the first threshold; and   the second thermo-mechanical valve unit prevents fuel from flowing to the main burner to thereby shut off the main burner, when the second thermo-mechanical valve unit determines that the temperature near the pilot light is equal to or below the second threshold.   
     
     
         3 . The water heating system of  claim 1 , further comprising:
 a switch that closes when the first thermo-mechanical valve unit permits fuel to flow to the pilot light; and   an electronic controller that controls the ignition unit to ignite the pilot light, when the electronic controller determines that the switch is closed.   
     
     
         4 . The water heating system of  claim 3 , further comprising:
 a battery that supplies electrical power to the electronic controller and the ignition unit; and   a thermopile that converts heat generated from the ignited main burners into electrical energy to recharge the battery.   
     
     
         5 . The water heating system of  claim 3 , further comprising:
 a battery that supplies electrical power to the electronic controller and the ignition unit; and   a solar cell that converts light generated from the ignited main burners into electrical energy to recharge the battery.   
     
     
         6 . The water heating system of  claim 3 , further comprising a solenoid piston that opens a safety valve of the first thermo-mechanical valve unit for a predetermined time period to permit fuel to flow to the pilot light,
 wherein the electronic controller controls the solenoid piston to open the safety valve for the predetermined time period, when the electronic controller determines that the switch is closed.   
     
     
         7 . The water heating system of  claim 6 , wherein after the solenoid piston is deactivated after the predetermined time period, a thermocouple powered by heat from the pilot light keeps the safety valve open to continue permitting fuel to flow to the pilot light after the solenoid piston is deactivated. 
     
     
         8 . The water heating system of  claim 6 , further comprising:
 a battery that supplies electronic power to the electronic controller, the ignition unit, and the solenoid piston; and   a thermopile that converts heat generated from the ignited main burners into electrical energy to recharge the battery.   
     
     
         9 . The water heating system of  claim 6 , further comprising:
 a battery that supplies electronic power to the electronic controller, the ignition unit, and the solenoid piston; and   a solar cell that converts light generated from the ignited main burners into electrical energy to recharge the battery.   
     
     
         10 . The water heating system of  claim 1 , wherein the pilot light remains lit while the temperature of the water is below the first threshold. 
     
     
         11 . The water heating system of  claim 1 , wherein the system is not connected to an external source of electrical power. 
     
     
         12 . A method for heating water in a water tank, performed by a water heating system including a main burner configured to heat the water in the water tank and a pilot light configured to ignite fuel to light the main burner, said method comprising:
 determining, by a first thermo-mechanical valve unit, whether temperature of the water is below a first threshold, and permitting fuel to flow to the pilot light, when the first thermo-mechanical valve unit determines that the temperature of the water is below the first threshold;   igniting, by an ignition unit, the pilot light, when the first thermo-mechanical valve unit permits fuel to flow to the pilot light; and   determining, by a second thermo-mechanical valve unit, whether the pilot light is ignited, and permitting fuel to flow to the main burner and be ignited by the pilot light, when the second thermo-mechanical valve unit determines that the ambient temperature near the pilot light is above a second threshold.   
     
     
         13 . The method of  claim 12 , further comprising:
 preventing, by the first thermo-mechanical valve unit, fuel from flowing to the pilot light, and thereby causing the pilot light to be extinguished, when the first thermo-mechanical valve unit determines that the temperature of the water is equal to or greater than the first threshold; and   preventing, by the second thermo-mechanical valve unit, fuel from flowing to the main burner, and thereby shutting off the main burner, when the second thermo-mechanical valve unit determines that the ambient temperature near the pilot light is equal to or below the second threshold.   
     
     
         14 . The method of  claim 12 , further comprising:
 closing a switch when the first thermo-mechanical valve unit permits fuel to flow to the pilot light; and   controlling the ignition unit, by an electronic controller, to ignite the pilot light, when the electronic controller determines that the switch is closed.   
     
     
         15 . The method of  claim 14 , further comprising:
 supplying electronic power, by a battery of the system, to the electronic controller and the ignition unit; and   converting, by a thermopile of the system, heat generated from the ignited main burners into electrical energy to recharge the battery.   
     
     
         16 . The method of  claim 14 , further comprising:
 supplying electronic power, by a battery of the system, to the electronic controller and the ignition unit; and   converting, by a solar cell of the system, light generated from the ignited main burners into electrical energy to recharge the battery.   
     
     
         17 . The method of  claim 14 , further comprising:
 opening, by a solenoid piston, a safety valve of the first thermo-mechanical valve unit for a predetermined time period to permit fuel to flow to the pilot light,   wherein the electronic controller controls the solenoid piston to open the safety valve for the predetermined time period, when the electronic controller determines that the switch is closed.   
     
     
         18 . The method of  claim 17 , wherein after the solenoid piston is deactivated after the predetermined time period, a thermocouple powered by heat from the pilot light keeps the safety valve open to continue permitting fuel to flow to the pilot light after the solenoid deactivates. 
     
     
         19 . The method of  claim 17 , further comprising:
 supplying electronic power, by a battery of the system, to the electronic controller, the ignition unit, and the solenoid piston; and   converting, by a thermopile of the system, heat generated from the ignited main burners into electrical energy to recharge the battery.   
     
     
         20 . The method of  claim 17 , further comprising:
 supplying electronic power, by a battery of the system, to the electronic controller, the ignition unit, and the solenoid piston; and   converting, by a solar cell of the system, light generated from the ignited main burners into electrical energy to recharge the battery.