Grid independent heating system

Abstract

An apparatus and method for producing heat and electricity independent of an electrical grid. The apparatus includes a burner adapted to produce at least one of radiant heat, flame and hot combustion gases. A thermal-to-electric conversion device is integrated with the burner and proximate to the burner, for producing electricity. The conversion device has a first side disposed toward the at least one of radiant heat, flame and hot combustion gases and a second side disposed toward and in heat transfer contact with a liquid supply line. The apparatus is useful in water heaters. The liquid supply line provides both water to be heated and a cooling medium for the thermal-to-electric conversion device.

What is claimed is: 
     
         1 . An apparatus for producing heat and electricity, the apparatus comprising:
 a burner adapted to produce at least one of radiant heat, flame and hot combustion gases;   a liquid supply line; and   a thermal-to-electric conversion device integrated with the burner and proximate to the burner, the conversion device having a first side disposed toward the at least one of radiant heat, flame and hot combustion gases and a second side disposed toward and in heat transfer contact with the liquid supply line.   
     
     
         2 . The apparatus of  claim 1 , wherein a surface of the first side of the conversion device is disposed at an angle to a flame axis. 
     
     
         3 . The apparatus of  claim 1 , further comprising an exhaust flue downstream of the burner, wherein the conversion device is offset from the burner between the burner and the exhaust flue and a surface of the first side of the conversion device is tilted at an angle toward the burner and away from the exhaust flue. 
     
     
         4 . The apparatus of  claim 3 , wherein the conversion device comprises a plurality of thermoelectric generators (TEGs) disposed around the burner. 
     
     
         5 . The apparatus of  claim 4 , wherein one or more sections of the liquid supply line extend through the plurality of thermoelectric generators before connection to a heated water outlet. 
     
     
         6 . The apparatus of  claim 1 , further comprising a heat sink on the second side of the conversion device. 
     
     
         7 . The apparatus of  claim 6 , wherein the heat sink comprises a plurality of cooling channels connected to the liquid supply line. 
     
     
         8 . The apparatus of  claim 7 , wherein the heat sink comprises an aluminum or copper body around the plurality of cooling channels. 
     
     
         9 . The apparatus of  claim 6 , further comprising a thermally conductive plate on the first side of the conversion device. 
     
     
         10 . The apparatus of  claim 9 , wherein the plate comprises a metal, an alloy, or a ceramic plate. 
     
     
         11 . The apparatus of  claim 1 , further comprising a thermally conductive plate on the first side of the conversion device. 
     
     
         12 . The apparatus of  claim 1 , comprising a water heater including a water storage tank, an inlet pipe for unheated water and an outlet pipe for heated water, wherein the liquid supply line is connected to the water inlet. 
     
     
         13 . The apparatus of  claim 12 , wherein the liquid supply line connects to the outlet pipe and/or the storage tank downstream of the conversion device. 
     
     
         14 . The apparatus of  claim 13 , further comprising a second storage tank downstream of the conversion device and in combination with the liquid supply line. 
     
     
         15 . The apparatus of  claim 13 , wherein the conversion device comprises a plurality of thermoelectric generators disposed around the burner, wherein one or more sections of the liquid supply line extends through at least adjacent pairs of the plurality of thermoelectric generator modules or heat sinks before connection back to the outlet pipe and/or the storage tank. 
     
     
         16 . The apparatus of  claim 1 , further comprising a pressure boosting device in combination with the liquid supply line upstream of the conversion device. 
     
     
         17 . A water heater including the apparatus of  claim 1  for heating a supply of water from or within the liquid supply line. 
     
     
         18 . The water heater of  claim 17 , further comprising:
 a water storage tank in heat transfer combination with the burner;   an exhaust flue downstream of the burner and extending along the water storage tank;   an unheated water inlet pipe upstream of the water storage tank; and   a heated water outlet pipe downstream of the storage tank;   wherein the liquid supply line is connected to the unheated water inlet pipe, the conversion device is offset from the burner between the burner and the exhaust flue and a surface of the first side of the conversion device is tilted at an angle toward the burner and away from the exhaust flue.   
     
     
         19 . A method for providing heat and electricity to a machine, the method comprising the steps of:
 introducing fuel and air to a burner;   producing radiant heat at least partially inside the flame housing;   converting thermal energy to electric energy with a thermal-to-electric conversion device integrated with the flame housing, wherein the thermal-to-electric conversion device includes a first side disposed at an angle toward and over the radiant heat; and   cooling a second side of the conversion device with a cooling flow of water.   
     
     
         20 . The method according to  claim 19 , further comprising introducing heated water exiting the conversion device to a heated water outlet or storage tank of a water heater.