Waste heat recovery system, gas turbine plant provided with same, waste heat recovery method, and installation method for waste heat recovery system

Abstract

A gas turbine including: a compressor that compresses air; a combustor that combusts fuel in the compressed air so as to generate combustion gas; and a turbine that is driven using the combustion gas. A plurality of cooling air coolers bleed the air from a plurality of places having different pressures in the compressor and cool the air bled from the respective places, thereby generating cooling air is provided. A waste heat recovery device that recovers waste heat from the at least two cooling air coolers among the plurality of cooling air coolers is provided.

1 . A waste heat recovery system comprising:
 a plurality of cooling air coolers that, in a gas turbine including a compressor that compresses air, a combustor that combusts fuel in the compressed air so as to generate combustion gas, and a turbine that is driven using the combustion gas, bleed the air from a plurality of places having different pressures in the compressor and cool the air bled from the respective places, thereby generating cooling air; and   a waste heat recovery device that recovers waste heat from the at least two cooling air coolers among the plurality of cooling air coolers,   wherein the waste heat recovery device recovers waste heat from higher air pressure parts of at least two cooling air coolers to a higher temperature heating medium as high-temperature waste heat, and   recovers waste heat from lower air pressure parts of the at least two cooling air coolers to a lower temperature heating medium as low-temperature waste heat.   
     
     
         2 . (canceled) 
     
     
         3 . A waste heat recovery system comprising:
 a plurality of cooling air coolers that, in a gas turbine including a compressor that compresses air, a combustor that combusts fuel in the compressed air so as to generate combustion gas, and a turbine that is driven using the combustion gas, bleed the air from a plurality of places having different pressures in the compressor and cool the air bled from the respective places, thereby generating cooling air; and   a waste heat recovery device that recovers waste heat from the at least two cooling air coolers among the plurality of cooling air coolers,   wherein the waste heat recovery device comprises a waste heat recovery boiler that heats water using exhaust gas from the turbine,   recovers waste heat from higher air pressure parts of the at least two cooling air coolers to a portion of the waste recovery boiler with a higher water temperature as high-temperature waste heat, and   recovers waste heat from lower air pressure parts of the at least two cooling air coolers to a portion of the waste heat recovery broiler with a lower water temperature as low-temperature waste heat.   
     
     
         4 . The waste heat recovery system according to  claim 1 ,
 wherein the waste heat recovery device comprises a waste heat recovery boiler that heats water using exhaust gas from the turbine,   recovers waste heat from higher air pressure parts of the at least two cooling air coolers to a portion of the waste recovery boiler with a higher water pressure as high-temperature waste heat, and   recovers waste heat from lower air pressure parts of the at least two cooling air coolers to a portion of the waste recovery boiler with a lower water pressure as low-temperature waste heat.   
     
     
         5 . (canceled) 
     
     
         6 . The waste heat recovery system according to  claim 1 ,
 wherein the waste heat recovery device comprises a plurality of low-boiling-point medium Rankine cycles in which low-boiling-point media each having a different boiling point repeat a cycle consisting of condensation, evaporation and circulation due to the recovered waste heat,   recovers waste heat from higher air pressure parts of the at least two cooling air coolers as high-temperature waste heat in the low-boiling-point medium Rankine cycle in which the low-boiling-point medium has a higher boiling point, and   recovers waste heat from lower air pressure parts of the at least two cooling air coolers as low-temperature waste heat in the low-boiling-point medium Rankine cycle in which the low-boiling-point medium has a lower boiling point.   
     
     
         7 . The waste heat recovery system according to  claim 1 ,
 wherein the waste heat recovery device comprises one low-boiling-point medium Rankine cycle in which a low-boiling-point media repeats a cycle consisting of condensation, evaporation, and circulation due to the recovered waste heat,   the low-boiling-point medium Rankine cycle:   recovers waste heat from higher air pressure parts of the at least two cooling air coolers to a location in which the low-boiling point media has a higher temperature as high-temperature waste heat, and   recovers waste heat from lower air pressure parts of the at least two cooling air coolers to a location in which the low-boiling point media has a lower pressure.   
     
     
         8 . The waste heat recovery system according to  claim 1 ,
 wherein the waste heat recovery device comprises: a low-boiling-point medium Rankine cycle in which low-boiling-point media each having a different boiling point repeat a cycle consisting of condensation, evaporation, and circulation, due to the recovered waste heat; and a Rankine cycle including a waste heat recovery boiler that heats water using exhaust gas from the turbine and a steam turbine that is driven using the water heated in the waste heat recovery boiler as an operating medium,   recovers waste heat from higher air pressure parts of the at least two cooling air coolers as high-temperature waste heat in the Rankine cycle, and   recovers waste heat from lower pressure parts of the at least two cooling air coolers as low-temperature waste heat in the low-boiling-point medium Rankine cycle.   
     
     
         9 . The waste heat recovery system according to  claim 6 ,
 wherein, the waste heat recovery device comprises the low-boiling point medium Rankine cycle including an evaporator that evaporates low-boiling-point media using waste heat from the cooling air coolers by recovering the waste heat using heating media,   a recovery line enabling the heating media that have recovered the waste heat in the cooling air coolers to flow toward the evaporator,   a returning line which communicates with the recovery line and enables the heating media which have delivered the waste heat to the evaporator to flow toward the cooling air coolers, and   a pump that circulates the heating media between the cooling air coolers and the evaporator through the recovery line and the returning line.   
     
     
         10 . The waste heat recovery system according to  claim 9 ,
 wherein the waste heat recovery device comprises   a bypass line which allows the recovery line and the returning line to communicate without the cooling air coolers and the evaporators being therebetween and thus enables the heating media to flow therebetween and   a flow rate-adjusting valve that adjusts a flow rate of the heating media which flow through the bypass line.   
     
     
         11 . The waste heat recovery system according to  claim 10 ,
 wherein the waste heat recovery device comprises a control device that adjusts the flow rate-adjusting valve so that a temperature of the cooling air which is generated in the cooling air coolers becomes constant.   
     
     
         12 . The waste heat recovery system according to  claim 9 ,
 wherein the waste heat recovery device comprises a waste heat recovery boiler that heats water using exhaust gas from the turbine and uses the water in the waste heat recovery boiler as the heating medium.   
     
     
         13 . The waste heat recovery system according to  claim 3 ,
 wherein the waste heat recovery device produces mixed wasted heat by mixing waste heat from part or all of the at least two cooling air coolers,   recovers waste heat having a higher temperature among the mixed waste heat and waste heat which is not mixed with the mixed waste heat as high-temperature waste heat, and   recovers waste heat having a lower temperature among the mixed waste heat and waste heat which is not mixed with the mixed waste heat as low-temperature waste heat.   
     
     
         14 . The waste heat recovery system according to  claim 13 ,
 wherein the waste heat recovery device generates the mixed waste heat by causing heating media to flow in parallel through part or all of the at least two cooling air coolers.   
     
     
         15 . The waste heat recovery system according to  claim 13 ,
 wherein part or all of the at least two cooling air coolers capable of recovering waste heat having a higher temperature is high-temperature side cooling air cooler,   part or all of the at least two cooling air coolers, the cooling air cooler capable of recovering waste heat having a lower temperature is low-temperature side cooling air cooler, and   the waste heat recovery device causes heating media to flow in series from the low-temperature side cooling air cooler to the high-temperature side cooling air cooler, thereby generating mixed waste heat.   
     
     
         16 . The waste heat recovery system according to  claim 13 ,
 wherein the waste heat recovery device generates the mixed waste heat by causing heating media to flow in parallel through part or all of the at least two cooling air coolers and generates mixed waste heat by flowing the heating media through a parallel cooling air cooler group including part or all of the at least two cooling air coolers through which the heating media flow in parallel and flowing in series the heating media through the parallel cooling air cooler group and the cooling air cooler not in the parallel cooling air cooler group.   
     
     
         17 . A gas turbine plant comprising:
 the waste heat recovery system according to  claim 1 ; and   the gas turbine including the compressor that compresses air, the combustor that generates combustion gas by combusting fuel in the compressed air, and the turbine that is driven using the combustion gas.   
     
     
         18 . A waste heat recovery method comprising:
 a bleeding step of bleeding air from a plurality of places having different pressures in a compressor in a gas turbine including the compressor that compresses air, a combustor that generates combustion gas by combusting fuel in the compressed air, and a turbine that is driven using the combustion gas;   a cooling step of cooling the air bled respectively from the plurality of places, thereby generating cooling air that cools high-temperature components; and   a waste heat recovery step of recovering waste heat generated when cooling air generated in at least two of the plurality of places corresponding to plurality of bleeding places,   wherein, in the waste heat recovery step,   waste heat obtained by cooling the air bled from a higher pressure place of the at least two places is recovered to a higher temperature heating medium as high-temperature waste heat, and   waste heat obtained by cooling the air bled from a lower pressure place of the at least two places is recovered to a lower temperature heating medium as low-temperature waste heat.   
     
     
         19 - 21 . (canceled) 
     
     
         22 . The waste heat recovery method according to  claim 18 ,
 wherein, in the waste heat recovery step,   the waste heat is recovered in a plurality of low-boiling-point medium Rankine cycles in which low-boiling-point media having different boiling points respectively repeat a cycle consisting of condensation, evaporation and circulation,   waste heat obtained by cooling the air bled from a higher pressure place of the at least two places is recovered as high-temperature waste heat in the low-boiling-point medium Rankine cycle in which the low-boiling-point medium has a higher boiling point, and   waste heat obtained by cooling the air bled from a lower pressure place of the at least two places is recovered as low-temperature waste heat in the low-boiling-point medium Rankine cycle in which the low-boiling-point medium has a lower boiling point.   
     
     
         23 . (canceled) 
     
     
         24 . The waste heat recovery method according to  claim 18 ,
 wherein, in the waste heat recovery step,   higher pressure waste heat obtained by cooling the air bled from the at least two places is recovered as high-temperature waste heat in a Rankine cycle including a waste heat recovery boiler that heats water using exhaust gas from the turbine and a steam turbine that is driven using the water heated in the waste heat recovery boiler as an operating medium, and   lower pressure waste heat obtained by cooling the air bled from the at least two places is recovered as low-temperature waste heat in a low-boiling-point Rankine cycle in which low-boiling-point media repeat a cycle consisting of condensation, evaporation, and circulation.   
     
     
         25 - 26 . (canceled) 
     
     
         27 . The waste heat recovery method according to  claim 18 ,
 wherein, in the waste heat recovery step,   mixed waste heat is produced by mixing part or all of the waste heat obtained by cooling the air bled from the at least two places,   waste heat having a higher temperature among the mixed waste heat and waste heat which are not mixed with the mixed waste heat is recovered as high-temperature waste heat, and   waste heat having a lower temperature among the mixed waste heat and waste heat which are not mixed with the mixed waste heat is recovered as low-temperature waste heat.   
     
     
         28 - 30 . (canceled) 
     
     
         31 . An installation method for waste heat recovery systems,
 wherein the waste heat recovery system according to  claim 1  is installed in the gas turbine.