Steam generator with attemperators

Abstract

An advantage steam generator and a steam generation system with an arrangement of heat-exchangers within a hot gas path. To protect the facilities and to increase the efficiency at least at the output of several heat-exchangers an attemperator is arranged, wherein each of them is connected via a fluid distribution valve with a distribution piping.

What is claimed is: 
     
         1 - 10 . (canceled) 
     
     
         11 . A steam generator with a hot gas path comprising:
 a superheater, which has a superheater output to deliver a flow of hot steam;   at least four heat exchangers;   an economizer; and   a distribution piping, wherein the superheater and the heat exchangers and the economizer are connected in series and each comprises a fluid input and at least one fluid distribution pipe and several heat exchange tubes arranged inside the hot gas path and at least one collection pipe and a fluid output, wherein the economizer input is connected with a source of cold fluid, wherein:
 at the superheater output and in the connection between the superheater and a first heat exchanger and in each connection between one heat exchanger and the respective next heat exchanger of the at least four heat exchangers at least one attemperator is arranged, wherein the distribution piping is connected with the source of cold fluid and with the economizer output and via respective valves with each of the attemperators. 
   
     
     
         12 . The steam generator according to  claim 11 , wherein:
 a main valve is arranged at the fluid input of a last heat exchanger in the series of heat exchangers; and/or   a fluid supply valve is arranged at the economizer input; and/or   a fluid bypass valve is arranged between the source of cold fluid and the distribution piping.   
     
     
         13 . The steam generator according to  claim 11 , wherein at least at one of the series of superheater and heat exchangers comprises at least two collection pipes each with an attemperator, in particular each of them is connected via a respective fluid distribution valve with the distribution piping. 
     
     
         14 . A steam generating system with a steam generator according to  claim 11 , further comprising:
 a control system, wherein the control system is able to control the fluid valves; and   a temperature determination system, which is able to determine the temperature of at least one of the fluid outputs and/or the fluid inputs; and/or   a vapor determination system, which is able to determine a share of vapor before and/or after at least one of the attemperators.   
     
     
         15 . The steam generating system according to  claim 14 , wherein:
 the temperature determination system is able to determine the temperature of each of the fluid outputs and/or the fluid inputs; and/or   the vapor determination system is able to determine the share of vapor at each of the attemperators.   
     
     
         16 . The steam generating system according to  claim 14 , wherein the control system is able to control the fluid valves separately and in groups and stepwise; in particular dependent to the temperature of the fluid outputs and/or dependent to the share of vapor at the attemperators. 
     
     
         17 . A method to control a steam generating system according to  claim 14 , comprising the steps:
 a) determine at least on temperature and/or temperature change at a fluid output;   b) compare the temperature/temperature change with a predetermined value; and   c) control at least one of the several fluid valves dependent on the comparison.   
     
     
         18 . The method to control a steam generating system according to  claim 17 , comprising the steps:
 a) determine at least on share of vapor at an attemperator;   b) compare the share of vapor with a predetermined value; and   c) control at least one of the several fluid valves dependent on the comparison.   
     
     
         19 . The method according to  claim 17 , wherein:
 the temperature and/or the temperature change at all fluid outputs is determined; and/or   the share of vapor at all attemperators is determined.   
     
     
         20 . The method according to  claim 18 , wherein the first and/or second and/or third and/or in particular fourth predetermined share of vapor is at least 60%, in particular at least 75%, and/or at most 90%, in particular at most 85%, of the mass flow.