Carbon dioxide recovery system and method

摘要

The carbon dioxide recovery system includes: a first steam line 21a through which low-pressure steam 14L is fed from an intermediate-pressure turbine 12 to a low-pressure turbine 13; a second steam line 21b into which the low-pressure steam 14L is branched from the first steam line 21a; a first regulation valve V1 for regulating the opening of the low-pressure steam 14L from 100% to 0%; a second regulation valve V2 for regulating the opening of the low-pressure steam 14L from 0% to 100% depending on the amount of control provided to the first regulation valve V1; a first auxiliary turbine 22A for recovering power using the low-pressure steam 14L being fed; and a first steam feed line 25L through which exhaust steam 23 discharged from the first auxiliary turbine 22A is supplied as a source of heat to a reboiler 24.

主权项

1. A carbon dioxide recovery system, comprising:
a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine; a boiler for producing steam to drive the turbines; a carbon dioxide recovery unit including a carbon dioxide absorber for allowing a carbon dioxide absorbent to absorb and reduce carbon dioxide in a combustion flue gas discharged from the boiler and a carbon dioxide regenerator for regenerating the carbon dioxide absorbent having absorbed carbon dioxide as a regenerated carbon dioxide absorbent; a first steam line through which low-pressure steam is fed from the intermediate-pressure turbine to the low-pressure turbine; a second steam line into which the low-pressure steam is branched from the first steam line; a first regulation valve disposed on the first steam line to regulate an opening of an amount of steam of the low-pressure steam from 100% to 0%; a second regulation valve disposed on the second steam line to regulate an opening of an amount of steam of the low-pressure steam from 0% to 100% depending on the amount of control provided to the first regulation valve; a first auxiliary turbine coupled to the second steam line to recover power using the low-pressure steam being fed; a first steam feed line through which exhaust steam discharged from the first auxiliary turbine is employed to be fed as a source of heat to a reboiler which is used to regenerate the carbon dioxide absorbent having absorbed carbon dioxide in the carbon dioxide regenerator; a bleed line through which the low-pressure steam having been bled from the first auxiliary turbine is fed to the low-pressure turbine; and a control device configured to control driving of the first auxiliary turbine by controlling an opening from 100% to 0% and from 0% to 100% in carbon dioxide recovery and non-recovery modes in response to a variation in operation load of the boiler or the turbines while a pressure of the exhaust steam supplied to the reboiler is maintained to take on a permissible value for a reboiler optimum pressure (about 0.33 MPa±0.05 MPa) with the first regulation valve and the second regulation valve being operated in response to each other.