Thermal power plant

Abstract

By improving a turbine efficiency, a power generation efficiency can be easily improved. The thermal power plant of the present invention comprises, for example: a boiler 1 that heats a feed water by utilizing a heat caused by combustion of a fossil fuel so as to generate a main steam A; reheaters 41 and 42 installed in the boiler 1 ; a turbine 2 ; and a generator 13 connected to the turbine 2 . The turbine 2 includes: a high pressure turbine into which the main steam A from the boiler 1 is introduced; an intermediate pressure turbine 9 into which the reheated steams E and F generated by the reheaters 41 and 42 are introduced, the intermediate pressure turbine 9 being uniaxially connected to the high pressure turbine 8 ; and a low pressure turbine 11 into which the reheated steams E and F discharged from the intermediate pressure turbine 9 is introduced, the low pressure turbine 11 being coupled with the high pressure turbine 8 and the intermediate pressure turbine 9 . The generator 7 has more than two poles, and is coupled with the high pressure turbine 8 , the intermediate pressure turbine 9 , and the low pressure turbine 11.

1 . A thermal power plant comprising:
 a boiler that heats a feed water by utilizing a heat caused by combustion of a fossil fuel so as to generate a main steam;   a high pressure turbine into which the main steam from the boiler is introduced, the high pressure turbine having a rotational shaft;   a reheater that reheats the main steam discharged from the high pressure turbine so as to generate a reheated steam;   an intermediate pressure turbine into which the reheated steam generated by the reheater is introduced, the intermediate pressure turbine having a rotational shaft that is coupled with the rotational shaft of the high pressure turbine;   a low pressure turbine into which the reheated steam discharged from the intermediate pressure turbine is introduced, the low pressure turbine having a rotational shaft that coupled with the rotational shafts of the high pressure turbine and the intermediate pressure turbine; and   a generator having more than two poles, and having a rotational shaft that is coupled with the rotational shafts of the high pressure turbine, the intermediate pressure turbine, and the low pressure turbine.   
     
     
         2 . The thermal power plant according to  claim 1 , further comprising a heat exchanger that heats a feed water to be introduced into the boiler, by utilizing a steam extracted from at least one of the high pressure turbine, the intermediate pressure turbine, and the low pressure turbine. 
     
     
         3 . The thermal power plant according to  claim 1 , further comprising a gas turbine system including: a compressor that compresses air; a combustor that burns a fuel with the air compressed by the compressor so as to generate a combustion gas; a gas turbine that is driven by the combustion gas generated by the combustor; and a gas turbine generator connected to the gas turbine;
 wherein the boiler is a heat recovery steam generator that heats the feed water by utilizing a heat of an exhaust gas discharged from the gas turbine system so as to generate a main steam.   
     
     
         4 . The thermal power plant according to  claim 1 , wherein
 an exhaust steam is discharged as a single flow from the low pressure turbine.   
     
     
         5 . The thermal power plant according to  claim 4 , wherein
 the exhaust steam is discharged in an axial direction from the low pressure turbine.   
     
     
         6 . The thermal power plant according to  claim 1 , wherein
 the generator is a 4-pole generator.   
     
     
         7 . The thermal power plant according to  claim 1 , comprising a plurality of reheaters and a plurality of intermediate pressure turbines, wherein
 reheated steam generated by the reheaters are introduced into the intermediate pressure turbines respectively.   
     
     
         8 . The thermal power plant according to  claim 1 , wherein
 the intermediate pressure turbine and the low pressure turbine are successively positioned without any connecting pipe.   
     
     
         9 . The thermal power plant according to  claim 1 , wherein:
 at least one of the main steam generated by the boiler and the reheated steam generated by the reheater is 620° C. or higher; and   at least one of the rotational shafts of the high pressure turbine and the intermediate pressure turbine into which the steam of 620° C. or higher is introduced is made of a material containing 8% to 15% of chrome.   
     
     
         10 . The thermal power plant according to  claim 1 , wherein:
 at least one of the main steam generated by the boiler and the reheated steam generated by the reheater is 545° C. or higher; and   at least one of the rotational shafts of the high pressure turbine and the intermediate pressure turbine into which the steam of 545° C. or higher is introduced is made of a material containing no more than 3% of chrome.