High-temperature steam turbine power plant with double reheat

Abstract

A steam power plant is described including on a single rotor at least one high pressure turbine or turbine section having a steam exit connected in operation to a first steam reheater and at least two intermediate pressure turbines or turbine sections with a first of the at least two intermediate pressure turbines or turbine sections having a steam exit connected in operation to a second steam reheater and with a second of the at least two intermediate pressure turbines or turbine sections having a steam entry to receive steam from the second steam reheater and a steam exit connected to one or more low pressure turbines or turbine sections, whereby the at least two intermediate pressure turbines or turbine sections are each separated into a high temperature turbine or turbine section and into a low temperature turbine or turbine section.

1 . A steam power plant comprising:
 at least one high pressure turbine or turbine section on a single rotor and having a steam exit connected in operation to a first steam reheater and   at least two intermediate pressure turbines or turbine sections with a first of the at least two intermediate pressure turbines or turbine sections having a steam exit connected in operation to a second steam reheater and with a second of the at least two intermediate pressure turbines or turbine sections having a steam entry to receive steam from the second steam reheater and a steam exit connected to one or more low pressure turbines or turbine sections, whereby the at least two intermediate pressure turbines or turbine sections are each separated into a high temperature turbine or turbine section and into a low temperature turbine or turbine section,   wherein the high temperature turbine or turbine section of the first of the at least two intermediate pressure turbines and the high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines are combined in a double-flow configuration in a single outer casing with separate steam entry and exit pipes for the first of the at least two intermediate pressure turbines and separate steam entry and exit pipes for the high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines.   
     
     
         2 . The steam power plant of  claim 1 , wherein a steam entry of the high temperature turbine or turbine section of the first of the at least two intermediate pressure turbines is connected to the exit of the first reheater and a steam exit of the high temperature turbine or turbine section of the first of the at least two intermediate pressure turbines is connected via a piped connection to the separate low temperature turbine or turbine section of the first of the at least two intermediate pressure turbines and a steam exit of the low temperature turbine or turbine section of the first of the at least two intermediate pressure turbine is connected via a return pipe to the second reheater. 
     
     
         3 . The steam power plant of  claim 1 , wherein a steam entry of the high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines is connected to the exit of the second reheater and a steam exit of the high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines is connected via a piped connection to the separate low temperature turbine or turbine section of the second of the at least two intermediate pressure turbines and a steam exit of the low temperature turbine or turbine section of the second of the at least two intermediate pressure turbines is connected via a feed pipe to at least one low pressure turbine. 
     
     
         4 . The steam power plant of  claim 1 , wherein a steam entry of the high temperature turbine or turbine section of the first of the at least two intermediate pressure turbines is connected to the exit of the first reheater and a steam exit of the high temperature turbine or turbine section of the first of the at least two intermediate pressure turbines is connected via a piped connection to the separate low temperature turbine or turbine section of the first of the at least two intermediate pressure turbines and a steam exit of the low temperature turbine or turbine section of the first of the at least two intermediate pressure turbine s is connected via a return pipe to the second reheater and wherein a steam entry of the high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines is connected to the exit of the second reheater and a steam exit of the high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines is connected via a piped connection to the separate low temperature turbine or turbine section of the second of the at least two intermediate pressure turbines and a steam exit of the low temperature turbine or turbine section of the second of the at least two intermediate pressure turbines is connected via a feed pipe to the at least one low pressure turbine. 
     
     
         5 . The steam power plant of  claim 1 , wherein at least one of the low temperature turbine or turbine sections of the first of the at least two intermediate pressure turbines and low temperature turbine or turbine section or high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines is a double-flow turbine in a single inner casing. 
     
     
         6 . The steam power plant of  claim 1 , wherein the high temperature turbine or turbine section of the first of the at least two intermediate pressure turbines and the high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines are manufactured to withstand a respective steam entry temperature of 650 degrees Celsius or more. 
     
     
         7 . The steam power plant of  claim 1 , wherein the high temperature turbine or turbine section of the first of the at least two intermediate pressure turbines and the high temperature turbine or turbine section of the second of the at least two intermediate pressure turbines are manufactured to withstand a respective steam entry temperature of 650 degrees Celsius or more and the low temperature turbine or turbine section of the first of the at least two intermediate pressure turbines and the low temperature turbine or turbine section of the second of the at least two intermediate pressure turbines are manufactured for a steam entry temperature of less than 650 degrees Celsius.