High Temperature Sensible Heat Recovery System

Abstract

Heat is reclaimed from a high temperature gasifier exhaust gas of between 250° C. and 20000C. A first duct receives the exhaust gas, and outputs it at a reduced temperature. A second duct receives a heat transfer fluid and outputs it at an elevated temperature. A heat transfer arrangement conducts heat extracted from the product gas to the heat transfer fluid (steam), thereby elevating the temperature of the heat transfer fluid. A heat pipe formed of sodium, potassium, rubidium, or lithium, has a first end for communicating with the high temperature exhaust gas and a second end for communicating with the heat transfer fluid. The heat pipe has an envelope formed of a selectable combination of stainless steel, Inconel, nickel, molybdenum, tungsten, niobium, carbon, carbon composite, and Hastelloy X, and a safety valve that ensures safe operation. An adiabatic zone is interposed between the first and second ducts.

1 . A system for reclaiming heat, the system comprising a heat transfer arrangement for transferring heat from a high temperature exhaust gas of a gasifier to a working fluid, and thereby reclaiming high temperature sensible heat from the high temperature exhaust has of the gasifier. 
     
     
         2 . The system of  claim 1 , wherein the gasifier is a plasma gassifier. 
     
     
         3 . The system of  claim 1 , wherein the high temperature exhaust gas is characterized by a temperature of approximately between 250 C and 2000 C. 
     
     
         4 . The system of  claim 1 , wherein said heat transfer arrangement comprises:
 a first duct having an inlet for receiving the high temperature exhaust gas, and an outlet for exhausting the high temperature exhaust gas at a reduced temperature;   a second duct having an inlet for receiving a heat transfer fluid and an outlet for exhausting the heat transfer fluid at an elevated temperature; and   a heat transfer arrangement for conducting heat extracted from the product gas in said first duct to the heat transfer fluid in said second duct, to elevate the temperature of the heat transfer fluid.   
     
     
         5 . The system of  claim 4 , wherein the heat transfer fluid is steam. 
     
     
         6 . The system of  claim 4 , wherein said heat transfer arrangement comprises a heat pipe formed of a selectable combination of sodium, potassium, rubidium, and lithium, said heat pipe having a first end for communicating with the high temperature exhaust gas in said first duct, and a second end for communicating with the heat transfer fluid in said second duct. 
     
     
         7 . The system of  claim 6 , wherein said heat pipe further comprises an envelope formed of stainless steel. 
     
     
         8 . The system of  claim 6 , wherein said heat pipe further comprises an envelope formed of Inconel. 
     
     
         9 . The system of  claim 6 , wherein said heat pipe further comprises an envelope formed of nickel. 
     
     
         10 . The system of  claim 6 , wherein said heat pipe further comprises an envelope formed of molybdenum. 
     
     
         11 . The system of  claim 6 , wherein said heat pipe further comprises an envelope formed of tungsten. 
     
     
         12 . The system of  claim 6 , wherein said heat pipe further comprises an envelope formed of niobium. 
     
     
         13 . The system of  claim 6 , wherein said heat pipe further comprises an envelope formed of a selectable combination of carbon and carbon composite. 
     
     
         14 . The system of  claim 6 , wherein said heat pipe further comprises an envelope formed of Hastelloy X. 
     
     
         15 . The system of  claim 6 , wherein there is further provided a safety valve associated with said heat pipe for ensuring safe operation. 
     
     
         16 . The system of  claim 6 , wherein there is further provided a heat transfer fin in said first duct for enhancing the transfer of heat from the high temperature exhaust gas to said heat pipe. 
     
     
         17 . The system of  claim 6 , wherein there is further provided an adiabatic zone interposed between said first and second ducts.