Oxy/fuel combustion system having combined convective section and radiant section

Abstract

A heat transfer system having a a radiant source, a first heat exchanger configured to permit a first fluid to flow therethrough, and a thermal shield configured to provide controlled radiative heat from the radiant source to the first exchanger. The radiant source is a flame. The thermal shield is a second heat exchanger configured to permit a second fluid to flow therethrough or a non-contact thermal shield fabricated from a material arranged to provide controlled radiative heat exposure from the radiant source to the first exchanger. Oxy/coal combustion systems are also disclosed.

1 . A heat transfer system comprising:
 a radiant source;   a first heat exchanger configured to permit a first fluid to flow therethrough; and   a thermal shield configured to provide controlled radiative heat from the radiant source to the first exchanger; and   wherein the radiant source is a flame and the thermal shield is a second heat exchanger configured to permit a second fluid to flow therethrough.   
   
   
       2 . The system of  claim 1 , wherein the first heat exchanger comprises a plurality of tubes that are capable of carrying the first fluid. 
   
   
       3 . The system of  claim 1 , wherein the thermal shield comprises a plurality of tubes that are capable of carrying the second fluid. 
   
   
       4 . The system of  claim 1 , wherein the configuration of the thermal shield includes a predetermined spacing between each of the plurality of tubes of the thermal shield. 
   
   
       5 . The system of  claim 1 , wherein the system includes a predetermined spacing between each of the plurality of tubes of the first heat exchanger. 
   
   
       6 . The system of  claim 1 , wherein the configuration of the system includes a predetermined spacing between the tubes of the first heat exchanger and the thermal shield. 
   
   
       7 . The system of  claim 1 , wherein the configuration of the thermal shield includes a predetermined spacing between each of a plurality of tubes of the first heat exchanger and between the tubes of the first heat exchanger and the thermal shield. 
   
   
       8 . The system of  claim 1 , further comprising a webbed connection between tubes of the thermal shield, between tubes of the first heat exchanger or between tubes of the thermal shield and first heat exchanger. 
   
   
       9 . The system of  claim 1 , wherein the first fluid differs from the second fluid in a property selected from the group of properties consisting of heat capacity, density, viscosity, thermal conductivity, pressure, phase, phase fraction, velocity, mass-flow, and combinations thereof. 
   
   
       10 . The system of  claim 1 , wherein the radiant source, the first heat exchanger and the thermal shield are positioned substantially within a furnace of a combustion system. 
   
   
       11 . The system of  claim 1 , wherein the flame is an oxy/coal flame. 
   
   
       12 . The system of  claim 1 , wherein the flame is a solid fuel flame. 
   
   
       13 . The system of  claim 1 , wherein the flame is an oxy/fuel flame with an oxygen concentration of at least 21 vol %. 
   
   
       14 . The system of  claim 1 , wherein the first fluid is steam. 
   
   
       15 . The system of  claim 1 , wherein the first fluid is a liquid water and steam mixture. 
   
   
       16 . The system of  claim 1 , wherein the second fluid is liquid water. 
   
   
       17 . An oxy/fuel combustion system comprising:
 a furnace arranged and disposed to provide a flame radiant source;   a first exchanger disposed in the furnace arranged and disposed to exchange radiant heat from the radiant source and steam for use in a steam turbine; and   a thermal shield configured to provide controlled radiative heat exposure from the radiant source to the first exchanger;   wherein the thermal shield is a second heat exchanger configured to permit a second fluid to flow therethrough.   
   
   
       18 . The system of  claim 17 , wherein the first heat exchanger is selected from the group consisting of a superheater, a reheater, an economizer and combinations thereof. 
   
   
       19 . The system of  claim 17 , wherein the radiant source is a solid fuel flame. 
   
   
       20 . The system of  claim 19 , wherein the solid fuel flame is an oxy/coal flame. 
   
   
       21 . The system of  claim 19 , wherein the solid fuel flame is an oxy/fuel flame with an oxygen concentration of at least 21 vol %. 
   
   
       22 . The system of  claim 17 , wherein the first heat exchanger comprises a plurality of tubes that are capable of carrying the second fluid. 
   
   
       23 . The system of  claim 17 , wherein the thermal shield is a heat exchanger configured to permit a second fluid to flow therethrough. 
   
   
       24 . The system of  claim 23 , wherein the thermal shield comprises a plurality of tubes that are capable of carrying the second fluid. 
   
   
       25 . The system of  claim 17 , wherein the configuration of the thermal shield includes a predetermined spacing between each of the plurality of tubes of the thermal shield. 
   
   
       26 . The system of  claim 17 , wherein the configuration of the thermal shield includes a predetermined spacing between each of the plurality of tubes of the first heat exchanger. 
   
   
       27 . The system of  claim 17 , wherein the configuration of the thermal shield includes a predetermined spacing between the tubes of the first heat exchanger and the thermal shield. 
   
   
       28 . The system of  claim 17 , wherein the configuration of the thermal shield includes a predetermined spacing between each of the plurality of tubes of the first heat exchanger and between the tubes of the first heat exchanger and the thermal shield. 
   
   
       29 . The system of  claim 17 , further comprising a webbed connection between tubes of the thermal shield, between tubes of the first heat exchanger or between tubes of the thermal shield and first heat exchanger. 
   
   
       30 . An oxy/fuel combustion system comprising:
 a furnace having a chamber arranged and disposed to provide a flame radiant source and to circulate combustion fluid;   a first heat exchanger configured to permit a first fluid to flow therethrough; and   a non-contact thermal shield fabricated from a material arranged to provide controlled radiative heat exposure from the radiant source to the first exchanger;   wherein the radiant source is a flame and the first heat exchanger and the thermal shield are disposed within the chamber and in contact with the combustion fluid.   
   
   
       31 . The system of  claim 30 , wherein the first heat exchanger comprises a plurality of tubes that are capable of carrying the first fluid. 
   
   
       32 . The system of  claim 30 , wherein the configuration of the thermal shield includes a predetermined spacing between each of the plurality of tubes of the first heat exchanger. 
   
   
       33 . The system of  claim 30 , wherein the configuration of the thermal shield includes a predetermined spacing between the tubes of the first heat exchanger and the thermal shield. 
   
   
       34 . The system of  claim 30 , wherein the radiant source, the first heat exchanger and the thermal shield are positioned substantially within a furnace of a combustion system. 
   
   
       35 . The system of  claim 30 , wherein the flame is an oxy/coal flame. 
   
   
       36 . The system of  claim 30 , wherein the flame is a solid fuel flame. 
   
   
       37 . The system of  claim 30 , wherein the flame is an oxy/fuel flame with an oxygen concentration of at least 21 vol %. 
   
   
       38 . The system of  claim 30 , wherein the first fluid is steam. 
   
   
       39 . The system of  claim 30 , wherein the first fluid is a liquid water and steam mixture.