Power generation system

Abstract

A system may include a turbine and a recuperative heat exchanger system. The recuperative heat exchanger system is configured to receive exhaust gases from the turbine. The recuperative heat exchanger system may include a precool section to cool the exhaust gases, a major heating section to receive the cooled the exhaust gases, and a minor heating section to receive the cooled the exhaust gases.

What is claimed: 
     
         1 . A system, comprising:
 a turbine; and   a recuperative heat exchanger system, wherein the recuperative heat exchanger system is configured to receive exhaust gases from the turbine, and the recuperative heat exchanger system comprises:
 a precool section to cool the exhaust gases, 
 a major heating section to receive the cooled the exhaust gases, and 
 a minor heating section to receive the cooled the exhaust gases. 
   
     
     
         2 . The system of  claim 1 , wherein the precool section further comprises one or more shell and tube heat exchangers with an annular distributor, and wherein the system is configured such that a fluid exiting an end of the minor heating section enters the precool section. 
     
     
         3 . The system of  claim 1 , wherein the major heating section operates at a higher temperature then the minor heating section. 
     
     
         4 . The system of  claim 1 , wherein the major heating section further comprises at least two heat exchangers in series, and the at least two heat exchangers are a printed circuit type heat exchanger and arrayed vertically. 
     
     
         5 . The system of  claim 1 , wherein the minor heating section further comprises at least two heat exchangers in series, and the at least two heat exchangers are a printed circuit type heat exchanger and arrayed vertically stacked. 
     
     
         6 . The system of  claim 1 , wherein the recuperative heat exchanger system further comprises a heat recovery section configured to add heat to the recycle heating section. 
     
     
         7 . The system of  claim 1 , wherein the major heating section is a recycle heating section and the minor heating section is an oxidant heating section. 
     
     
         8 . The system of  claim 1 , further comprising one or more valves configured to balance a flow between the major heating section and the minor heating section. 
     
     
         9 . The system of  claim 1 , further comprising a manifold configured to split a flow from the precool section to the major heating section and the minor heating section. 
     
     
         10 . A method, comprising:
 producing exhaust gas via a turbine;   feeding the exhaust gas into a precool section of a recuperative heat exchanger system to cool the exhaust gas;   splitting the cooled exhaust gas into a major flow path feeding into a major heating section of the recuperative heat exchanger system and a minor flow path feeding into a minor heating section of the recuperative heat exchanger system;   flowing, in the minor flow path the cooled exhaust gas through a first minor heat exchanger of the minor heating section and a second minor heat exchanger of the minor heating section;   flowing, in the major flow path the cooled exhaust gas through a first major heat exchanger of the major heating section, a second major heat exchanger of the major heating section, and a third major heat exchanger of the major heating section; and   providing a combustor, coupled to the turbine, with fluid flow from the major flow path and the minor flow path.   
     
     
         11 . The method of  claim 10 , further comprising cooling the exhaust gas in the precool section to a temperature of 575° C. 
     
     
         12 . The method of  claim 10 , further comprising heating the minor flow path to a temperature of 350-500° C. 
     
     
         13 . The method of  claim 10 , further comprising heating the major flow path to a temperature of 520-650° C. 
     
     
         14 . The method of  claim 10 , further comprising adding heat to the major flow path via a heat source. 
     
     
         15 . The method of  claim 10 , further comprising balancing the splitting of the cooled exhaust gas into the major flow path and the minor flow path with one or more valves. 
     
     
         16 . A precool heat exchanger, comprising:
 a first annular shell forming a pressure boundary, the first annular shell comprises:
 an exhaust gas inlet configured to receive exhaust gas from a turbine, and 
 one or more exhaust outlets configured to exhaust the exhaust gas, 
   a second annular shell provided within the first annular shell;   a tube bundle provided within the second annular shell; and   an annular distribution device provided within the second annular shell, wherein the annular distribution device is configured to control an exhaust gas flow entering the tube bundle.   
     
     
         17 . The precool heat exchanger of  claim 16 , wherein the tube bundle is a U-tube bundle. 
     
     
         18 . The precool heat exchanger of  claim 17 , further comprising a support plate within the first annular shell configured to support a weight of the U-tube bundle. 
     
     
         19 . The precool heat exchanger of  claim 16 , further comprising a stationary head channel at an end of the first annular shell, the stationary head channel comprises an inlet configured to receive oxidant from a minor heating section; and an outlet configured to exit the oxidant. 
     
     
         20 . The precool heat exchanger of  claim 19 , wherein the stationary head channel further comprises a pass partition configured to split flow between the inlet and the outlet.