Waste heat recovery for forced convection biomass stove

Abstract

A stove includes a combustion chamber for producing heat, a thermoelectric device thermally coupled to a hot source and a cold source, a battery, a fan electrically connected to the thermoelectric device and the battery, and a controller configured to monitor the battery and thermoelectric device and configured to direct the fan be operated from power provided from the battery when power produced from the thermoelectric device is insufficient to power the fan.

1 . A stove, comprising:
 a combustion chamber for producing heat;   a thermoelectric device thermally coupled to a hot source and a cold source;   a battery;   a fan electrically connected to the thermoelectric device and the battery; and   a controller configured to monitor the battery and thermoelectric device and further configured to direct that the fan be operated from power provided from the battery when power produced from the thermoelectric device is insufficient to power the fan.   
     
     
         2 . The stove of  claim 1 , further comprising a hot flue gas duct and a cold air inlet duct, and the thermoelectric device is thermally coupled to the hot flue gas duct and the cold air inlet duct. 
     
     
         3 . The stove of  claim 1 , wherein the thermoelectric device is located on a hot surface of the stove and the cold source is ambient air. 
     
     
         4 . The stove of  claim 1 , wherein the controller is configured to monitor one or more temperatures, and the controller is configured to determine the thermoelectric device is producing power from one of the monitored temperatures. 
     
     
         5 . The stove of  claim 1 , wherein the controller is configured to determine a state of charge of the battery, a power consumed by the fan, and a power produced by the thermoelectric device, and when the battery is not fully charged, and the thermoelectric device is producing more power than is consumed by the fan, the controller directs that the battery receive power from the thermoelectric device to charge the battery. 
     
     
         6 . The stove of  claim 1 , wherein the controller is configured to determine a state of charge of the battery, a power consumed by the fan, and a power produced by the thermoelectric device, and when the battery is fully charged, and the thermoelectric device is producing more power than is consumed by the fan, the controller directs that excess power produced by the thermoelectric device be directed to a resistor. 
     
     
         7 . The stove of  claim 1 , further comprising a resistor, and the controller is configured to direct the thermoelectric device to dissipate excess power produced by the thermoelectric device to the resistor. 
     
     
         8 . The stove of  claim 7 , wherein the resistor is a radio, a light, an electric resistor, or any power load. 
     
     
         9 . The stove of  claim 1 , wherein the controller is configured to monitor one or more temperatures, and the controller is configured to reduce a speed of the fan when a temperature is above a predetermined limit. 
     
     
         10 . The stove of  claim 1 , wherein the controller is configured to monitor one or more temperatures, and the controller is configured to increase a speed of the fan when a temperature is below a predetermined limit. 
     
     
         11 . The stove of  claim 1 , further comprising a hot flue gas duct and a cold air inlet duct and a recuperator that is thermally coupled to the hot flue gas duct and the cold air inlet duct. 
     
     
         12 . The stove of  claim 1 , further comprising a heating plate and a Stirling engine that is thermally coupled to the heating plate. 
     
     
         13 . The stove of  claim 1 , wherein the combustion chamber is configured to burn solid fuel. 
     
     
         14 . The stove of  claim 1 , comprising a combustion chamber configured to burn solid fuel and a combustion chamber configured to burn liquid fuel. 
     
     
         15 . A method for operating a stove, comprising:
 operating a fan from battery power, wherein the fan forces air to a combustion chamber of the stove;   burning fuel in the combustion chamber;   monitoring a temperature of the stove; and   when the temperature of the stove is at or above a predetermined limit, switching power to operate the fan from battery power to power produced by a thermoelectric device thermally coupled to a hot source and a cold source.   
     
     
         16 . A method for operating a stove, comprising:
 burning fuel in a combustion chamber of the stove;   monitoring a temperature of the stove;   when the temperature of the stove is at or above a predetermined limit, operating a fan from power produced by a thermoelectric device thermally coupled to a hot source and a cold source; and   operating the fan and charging a battery from power produced by the thermoelectric device.   
     
     
         17 . A stove, comprising:
 a combustion chamber for producing heat;   a thermoelectric device thermally coupled to a hot source and a cold source;   a battery;   a fan electrically connected to the thermoelectric device and the battery; and   a controller configured to direct when the fan is to be operated from power provided from the battery or from power produced from the thermoelectric device.