Forced cooling in steam turbine plants

Abstract

A turbine plant ( 3 ), in particular a steam turbine plant, and a method ( 100 ) for cooling the turbine plant ( 3 ). The turbine plant ( 3 ) has a turbine ( 29 ) through which a process gas ( 15 ) flows in a flow direction ( 27 ) during operation. A cooling medium ( 7 ) is drawn or blown ( 120 ) through the turbine ( 29 ) either in or counter to the process gas flow direction ( 27 ) respectively, cooling the turbine ( 29 ). A fan ( 6 ) may be coupled to either a turbine inlet ( 4 ) or to a turbine outlet ( 5 ). The fan acts on the cooling medium ( 7, 110 ) which is drawn into the turbine ( 29 ) through the turbine inlet ( 4 ) or through the turbine outlet ( 5 ) to be blown ( 120 ) through the turbine ( 29 ) in or counter to the process gas flow direction ( 27 ).

1 . A turbine plant comprising:
 a turbine having a turbine inlet and a turbine outlet, the turbine is configured for causing a process gas to flow through the turbine in a flow direction from the turbine inlet to the turbine outlet during operation of the turbine;   a fan coupled to the turbine outlet and configured and operable to suck a coolant, which is drawn into the turbine by the fan and via the turbine inlet, is drawn through the turbine in the process gas flow direction; and   a bypass connected to a further coolant supply and arranged at an inlet of the fan from the bypass and the bypass is configured to supply a further coolant to be admixed with the coolant leaving the turbine and the admixed coolant being drawn into the fan.   
     
     
         2 . The turbine plant as claimed in  claim 1 , wherein the fan is coupled to the turbine outlet, a waste steam duct at the turbine outlet, wherein the fan is configured and operable to draw the coolant into the turbine via the turbine inlet and to suck the coolant through the turbine in the operational process gas flow direction. 
     
     
         3 . The turbine plant as claimed in  claim 15 , wherein the fan is coupled to the turbine inlet, a fresh steam/HZU/overflow supply line at the turbine inlet, wherein the fan is configured and operable to draw the coolant into the turbine via the turbine outlet and to suck the coolant through the turbine counter to the operational process gas flow direction. 
     
     
         4 . The turbine plant as claimed in  claim 1 , further comprising:
 a high-pressure turbine section, an intermediate-pressure turbine section and/or a low-pressure turbine section to which the fan is coupled and the fan is coupled to a waste steam duct or to a fresh steam/HZU/overflow supply line of the high-pressure turbine section, of the intermediate-pressure turbine section and/or of the low-pressure turbine section.   
     
     
         5 . The turbine plant as claimed in  claim 1 , wherein the coolant is ambient air; and
 the fan is coupled to a valve configured for controlling, regulating and/or governing the flow of ambient air into the turbine.   
     
     
         6 . The turbine plant as claimed in  claim 1 , wherein the process gas is steam. 
     
     
         7 . The turbine plant as claimed in  claim 1 , further comprising the turbine has an air pipe, the air pipe is disposed between two valves;
 the air pipe is generally at the turbine inlet, the pipe is configured and connected to receive and conduct the coolant, the valves being configured to govern coolant flow through the air pipe by acting on at least one of the valves, and the fan being configured and operable to cause coolant, controlled, regulated and/or governed by operation of at least one of the valves to be sucked into and through the turbine by means of the fan governed by operation of the at least one of the valves.   
     
     
         8 . The turbine plant as claimed in  claim 1 , wherein the turbine is a multi-part steam turbine without a low-pressure turbine section, or is a turbine section of a a multi-part steam turbine without a low-pressure turbine section. 
     
     
         9 . A method for cooling a turbine plant having a turbine with a turbine inlet and a turbine outlet;
 the method comprising:   flowing a process gas in a flow direction from the turbine inlet to the turbine outlet during operation of the turbine;   stopping operation of the turbine;   for cooling the turbine after operation has stopped:   drawing a coolant into the turbine by operating a fan coupled to the turbine inlet for drawing the coolant through the turbine in the process gas flow direction during operation of the turbine, whereby the turbine is cooled by the coolant drawn into the turbine.   
     
     
         10 . The method for cooling a turbine plant as claimed in  claim 9 , further comprising drawing the coolant into the turbine via an air pipe, which is arranged in a supply line of the turbine between two valves, wherein the supply line is on a fresh steam side (FD side) of a high-pressure turbine section of the turbine, and further comprising before the coolant that is drawn into the fan enters the fan, admixing a further coolant, with the coolant. 
     
     
         11 . The method for cooling a turbine plant as claimed in  claim 10 , wherein one of the valves is a quick-closing valve and the other is a control valve;
 the method further comprising using at least one of the valves to control, regulate and/or govern aspiration of the coolant into the turbine.   
     
     
         12 . The method for cooling a turbine plant as claimed in  claim 10 , further comprising admixing the further coolant in a controlled, regulated and/or governed manner, using a control valve so that the admixing is dependent on a turbine temperature and/or on the temperature of the coolant aspirated by the fan and/or on the temperature of the admixed further coolant and/or on the temperature of the coolant and further coolant mixture expelled by the fan. 
     
     
         13 . The method for cooling a turbine plant as claimed in  claim 1 , employed in a turbine plant without a condenser, in particular in a back-pressure turbine plant. 
     
     
         14 . The method for cooling a turbine plant as claimed in  claim 10 , wherein the further coolant comprises ambient air. 
     
     
         15 . A turbine plant comprising:
 a turbine having a turbine inlet and a turbine outlet, the turbine is configured for causing a process gas to flow through the turbine in a flow direction from the turbine inlet to the turbine outlet during operation of the turbine;   a fan coupled to the turbine inlet and configured and operable to suck a coolant, which is drawn into the turbine by the fan and via the turbine outlet, and is drawn through the turbine counter to the process gas flow direction; and   a bypass connected to a further coolant supply and arranged at an inlet of the fan from the bypass and the bypass is configured to supply a further coolant to be admixed with the coolant leaving the turbine and the admixed coolant being drawn into the fan.   
     
     
         16 . A method for cooling a turbine plant having a turbine with a turbine inlet and a turbine outlet;
 the method comprising:   flowing a process gas in a flow direction from the turbine inlet to the turbine outlet during operation of the turbine;   stopping operation of the turbine;   for cooling the turbine after operation has stopped:   drawing a coolant into the turbine by operating a fan coupled to the turbine outlet for drawing the coolant through the turbine counter to the process gas flow direction during operation of the turbine, whereby the turbine is cooled by the coolant drawn into the turbine.   
     
     
         17 . The method for cooling a turbine plant as claimed in  claim 9 , further comprising drawing the coolant into the turbine via an air pipe, which is arranged in a supply line of the turbine between two valves, wherein the supply line is in a supply line of a hot intermediate superheater side (HZU side) of an intermediate-pressure turbine section of the turbine and further comprising before the coolant that is drawn into the fan enters the fan, admixing a further coolant, with the coolant.