Method for operating an internal combustion engine having a steam power plant

Abstract

A method for operating an internal combustion engine ( 10 ) having a steam power plant ( 12 ), in which the exhaust gas of the internal combustion engine ( 10 ) at least indirectly heats the steam and this steam drives a turbine ( 26 ), the steam power plant ( 12 ) being sometimes, in particular at the beginning of operation, initially operated in a protection operating mode, in which the protection of the turbine ( 26 ) from damage by water droplets has priority.

1 . A method for operating an internal combustion engine ( 10 ) having a steam power plant ( 12 ), in which the exhaust gas of the internal combustion engine ( 10 ) at least indirectly heats the steam and this steam drives a turbine ( 26 ), characterized in that the steam power plant ( 12 ) is, under certain circumstances, initially operated in a protection operating mode, in which the protection of the turbine ( 26 ) from damage by liquid droplets has priority. 
     
     
         2 . A method according to  claim 1 , characterized in that a relative velocity between an incoming steam jet and a rotor ( 30 ) of the turbine ( 26 ) is reduced in the protection operating mode in relation to a normal operating mode. 
     
     
         3 . A method according to  claim 2 , characterized in that the relative velocity between the incoming steam jet and the rotor ( 30 ) of the turbine ( 26 ) is reduced in that at least sometimes a cross section of a nozzle ( 28 ) for controlling the incoming steam jet is enlarged and/or the turbine ( 26 ) is operated without a load ( 42 ) and/or the rotation of the turbine ( 26 ) is supported by a motor ( 48 ). 
     
     
         4 . A method according to  claim 1 , characterized in that a temperature of the steam generated in a steam generator ( 17 ) is increased up to a limiting value above a normal operating temperature in the protection operating mode in relation to the normal operating mode. 
     
     
         5 . A method according to  claim 4 , characterized in that the temperature of the steam is increased up to a limiting value above the normal operating temperature, in that an exhaust-side bypass ( 19 ) of a heat exchanger ( 18 ) is closed or reduced in its flow rate, if the operating temperature falls below a permissible operating temperature of the heat exchanger ( 18 ), and/or a delivery quantity of a feed pump ( 40 ) is adapted, and/or the cooling of a condenser ( 34 ) is stopped or reduced, if the operating pressure falls below a maximum permissible operating pressure of the steam power plant ( 12 ). 
     
     
         6 . A method according to  claim 1 , characterized in that the protection operating mode is ended when the steam power plant ( 12 ) has reached a normal operating temperature. 
     
     
         7 . A method according to  claim 1 , characterized in that at least an operating pressure of the steam power plant ( 12 ), a pressure ratio between an inlet ( 24 ) and an outlet ( 32 ) of the turbine ( 26 ), a fluid mass flow of a feed pump ( 40 ), a temperature of a heat exchanger ( 18 ) between exhaust gas and steam, a temperature of a condenser ( 34 ), and/or a temperature of the turbine ( 26 ) is monitored. 
     
     
         8 . A method according to  claim 1 , characterized in that when the pressure ratio between the inlet ( 24 ) and the outlet ( 32 ) of the turbine ( 26 ) reaches or exceeds a threshold value, the delivery quantity of a feed pump ( 40 ) is reduced. 
     
     
         9 . A method according to  claim 1 , characterized in that a superheating temperature of the steam in normal operation is between 270° C. and 360° C. 
     
     
         10 . A computer program ( 54 ) characterized in that it is programmed for application in a method according to  claim 1 . 
     
     
         11 . A storage medium ( 52 ) for a control and/or regulating unit ( 50 ), characterized in that a computer program ( 54 ) for application in a method according to  claim 1  is stored thereon. 
     
     
         12 . A control and/or regulating unit ( 50 ), characterized in that it is programmed for application in a method according to  claim 1 . 
     
     
         13 . A method according to  claim 1 , wherein the steam power plant ( 12 ) is operated in a protection operating mode at the beginning of operation. 
     
     
         14 . A method for operating an internal combustion engine ( 10 ) having a steam power plant ( 12 ), in which the exhaust gas of the internal combustion engine ( 10 ) at least indirectly heats the steam and this steam drives a turbine ( 26 ), the method comprising: determining if the steam power plant or the internal combustion engine is in a startup state; and, if so, operating the steam power plant in a protection operating mode. 
     
     
         15 . A method according to  claim 14 , further comprising: determining whether the startup state is completed; and, if so, operating the steam power plant in a normal operating mode.