Waste heat recovery boiler system and method of operating the same

Claim 2

A waste heat recovery boiler system com­prising: a plurality of waste heat recovery boilers each having a main steam generator and a reheater capable of generating main steam and reheat steam by heat derived from a hot waste gas; a main steam common pipe into which the flows of main steams generated by the main steam generators are introduced; a high-temperature reheat steam common pipe into which flows of the reheat steams from the reheaters are introduced through respective high-temperature reheat steam branch pipes so that the flows of said reheat steams form a single flow of reheat steams which is served through said common high-temperature reheat steam pipe; a low-temperature reheat steam common pipe from which a low-temperature reheat steam is supplied to the reheaters through respective low-­temperature reheat steam branch pipes; and at least one steam flow controller provided in at least one of the branch pipes connected to one of said high-temperature steam common pipe and said low-temperature steam common pipe and capable of con­trolling the flow rate of the steam flowing through the reheater connected to said branch pipe having said steam flow controller.

Claim 3

A reheating multiple combined plant comprising a plurality of gas turbines, a plurality of waste heat recovery boilers associated with the respective gas turbines, said waste heat recovery boilers each having a main steam generator and a reheater capable of generat­ing main steam and reheat steam by the heat derived from the waste gas from the associated gas turbine, a steam turbine having at least one high-pressure turbine and at least one low-pressure turbine, a main steam pipe through which a single flow of the main steam formed by flows of the main steams from said main steam generators is introduced to said high-pressure turbine of said steam turbine, a high-temperature reheat steam common pipe into which the flows of reheat steams from said reheaters of said waste heat recovery boilers join through respective high-temperature reheat steam branch pipes extending from said reheaters, said single flow of said high-temperature reheat steams being supplied through said high-temperature reheat steam common pipe into said low-pressure turbine of said steam turbine, and a low-temperature reheat steam common pipe through which steam from said high-pressure steam turbine is distributed to low-temperature reheat steam branch pipes leading to said reheaters, and at least one flow rate control means provided in at least one of said branch pipes connected to one of said high-­temperature reheat steam common pipe and said low-­temperature heat steam common pipe.

Claim 4

A reheating multiple combined plant comprising a plurality of gas turbines, a plurality of waste heat recovery boilers associated with the respective gas turbines, said waste heat recovery boilers each having a main steam generator and a reheater capable of generat­ing main steam and reheat steam by the heat derived from the waste gas from the associated gas turbine, a steam turbine having at least one high-pressure turbine and at least one low-pressure turbine, a main steam pipe through which a single flow of the main steam formed by flows of the main steams from said main steam generators is introduced to said high-pressure turbine of said steam turbine, a high-temperature reheat steam common pipe into which the flows of reheat steams from said reheaters of said waste heat recovery boilers join through respective high-temperature reheat steam branch pipes extending from said reheaters, said single flow of said high-temperature reheat steams being supplied through said high-temperature reheat steam common pipe into said low-pressure turbine of said steam turbine, and a low-temperature reheat steam common pipe through which steam from said high-pressure steam turbine is distributed to low-temperature reheat steam branch pipes leading to said reheaters, and at least one flow rate control means provided in at least one of said branch pipes connected to one of said high-­temperature reheat steam common pipe and said low-­temperature heat steam common pipe.

Claim 5

A reheating multiple combined plant comprising a plurality of waste heat recovery boilers (10;20) each having a main steam generator and a reheater (13,23) capable of generating main steam and reheat steam by the heat derived from a hot waste gas, a steam turbine (30) having at least one high-pressure turbine and at least one low-­pressure turbine, a main steam pipe (14,24) through which a single flow of the main steam formed by flows of the main steams from said main steam generators is introduced into said high-pressure turbine of said steam turbine, a high-temperature reheat steam common pipe (16,26) into which the flows of reheat steam from said reheaters (13,23) of said waste heat recovery boilers (10,20) join through respective high-temperature reheat steam branch pipes (16,26) leading from said reheaters (13;23), said single flow of said high-temperature reheat steam being supplied through said high-temperature reheat steam common pipe (16,26) into said low-pressure turbine of said steam turbine (30), and a low-temperature reheat steam common pipe (15,25) through which steam from said high-­pressure steam turbine (31) is distributed to low-temperature reheat steam branch pipes (15,25) leading to said reheaters (13,23), and at least one flow rate control means (51,61) provided in at least one of said branch pipes connected to one of said high-temperature reheat steam common pipe (16,26) and said low-­temperature reheat steam common pipe(15,25).

Claim 6

A reheating multiple combined plant comprising a plurality of waste heat recovery boilers (10;20) each having a main steam generator and a reheater (13,23) capable of generating main steam and reheat steam by the heat derived from a hot waste gas, a steam turbine (30) having at least one high-pressure turbine and at least one low-­pressure turbine, a main steam pipe (14,24) through which a single flow of the main steam formed by flows of the main steams from said main steam generators is introduced into said high-pressure turbine of said steam turbine, a high-temperature reheat steam common pipe (16,26) into which the flows of reheat steam from said reheaters (13,23) of said waste heat recovery boilers (10,20) join through respective high-temperature reheat steam branch pipes (16,26) leading from said reheaters (13;23), said single flow of said high-temperature reheat steam being supplied through said high-temperature reheat steam common pipe (16,26) into said low-pressure turbine of said steam turbine (30), and a low-temperature reheat steam common pipe (15,25) through which steam from said high-­pressure steam turbine (31) is distributed to low-temperature reheat steam branch pipes (15,25) leading to said reheaters (13,23), and at least one flow rate control means (51,61) provided in at least one of said branch pipes connected to one of said high-temperature reheat steam common pipe (16,26) and said low-­temperature reheat steam common pipe(15,25).

Claim 9

The method according to Claim 4, wherein the flow rate of the main steam from the associated main steam generator is used as said one of the load level applied to the gas turbine associated with said reheater and said process amount which is determined by said load level.

Claim 10

The method according to Claim 4, wherein the flow rate of the feedwater supplied to the associated main steam generator is used as said one of the load level applied to the gas turbine associated with said reheater and said process amount which is determined by said load level.

Claim 11

The method according to Claim 4, wherein the output power of an alternator driven by the associated gas turbine is used as said one of the load level applied to the gas turbine associated with said reheater and said process amount which is determined by said load level.

Claim 12

The method according to Claim 4, wherein the rate of supply of the fuel to the associated gas turbine is used as said one of the load level applied to the gas turbine associated with said reheater and said process amount which is determined by said load level.

Claim 15

The method according to Claim 9, wherein the flow rate of the main steam is used as said one of the load level applied to the gas turbine associated with said reheater and said process amount which is determined by said load level.

Claim 16

The method according to Claim 9, wherein the flow rate of the feedwater supplied to said main steam generator is used as said one of the load level applied to the gas turbine associated with said reheater and said process amount which is determined by said load level.

Claim 17

The method according to Claim 9, wherein the output power of an alternator driven by said gas turbine is used as said one of the load level applied to the gas turbine associated with said reheater and said process amount which is determined by said load level.

Claim 18

The method according to Claim 9, wherein the rate of supply of the fuel to said gas turbine is used as said one of the load level applied to the gas turbine associated with said reheater and said process amount which is determined by said load level.

Claim 21

The method according to Claim 14, wherein the flow rate of the main steam from the associated main steam generator is used as said one of the heat energy possessed by said hot waste gas introduced into the associated waste heat recovery boiler and said process amount which is determined by said heat energy.

Claim 22

The method according to Claim 14, wherein the flow rate of the feedwater supplied to the associated main steam generator is used as said one of the heat energy possessed by said hot waste gas introduced into the associated waste heat recovery boiler and said process amount which is determined by said heat energy.

Claim 25

The method according to Claim 17, wherein the flow rate of the main steam from the associated main steam generator is used as said one of the heat energy possessed by said hot waste gas introduced into the associated waste heat recovery boiler and said process amount which is determined by said heat energy.

Claim 26

The method according to Claim 17, wherein the flow rate of the feedwater supplied to the associated main steam generator is used as said one of the heat energy possessed by said hot waste gas introduced into the associated waste heat recovery boiler and said process amount which is determined by said heat energy.