System and method for controlling waste heat for co2 capture

Abstract

The present invention relates to systems and methods for controlling the flow of steam provided to a gas recovery unit 130 based on changes to steam flow to and/or power generated by a power generation unit 119 . The gas recovery unit 130 may be part of a thermal power generation unit and may be an amine based CO 2 recovery unit including two or more regenerator columns 153.

1 . A plant, comprising:
 a boiler unit that produces steam;   a power generation unit comprising at least one power generation turbine that receives the steam from the boiler unit;   a gas recovery unit comprising two or more regenerator columns;   a secondary source of steam to the two or more regenerator columns; and   a controller configured to regulate the flow rate of steam to two or more regenerator columns;   wherein the controller comprises a control strategy that determines the flow rate of steam from the source of steam to each regenerator of the two or more regenerator columns based on a plant load parameter.   
     
     
         2 . The plant of  claim 1 , further comprising a second controller configured to further regulate the flow of steam from the source of steam to at least one regenerator column of the two or more regenerator columns, the second controller comprising a control strategy the determines the flow rate of steam to the gas recovery unit based on total power generation of the power generation unit. 
     
     
         3 . The plant of  claim 1 , wherein the secondary source of steam comprises an auxiliary turbine. 
     
     
         4 . The plant of  claim 1 , wherein the power generation unit comprises a high pressure turbine, and high pressure steam is provided to the secondary source of steam from a high pressure steam feed to the high pressure turbine. 
     
     
         5 . The plant of  claim 1 , wherein the power generation unit comprises a high pressure turbine and an intermediate pressure turbine, and intermediate pressure steam is provided to the secondary source of steam from an intermediate pressure steam feed from the high pressure turbine to the intermediate pressure turbine. 
     
     
         6 . The plant of  claim 1 , wherein the power generation unit comprises a high pressure turbine, an intermediate pressure turbine, and a low pressure turbine, and low pressure steam is provided to the secondary source of steam from a low pressure steam feed from the intermediate pressure turbine to the low pressure turbine. 
     
     
         7 . The plant of  claim 1 , wherein the gas recovery unit comprises an amine based scrubbing process. 
     
     
         8 . The plant of  claim 1 , wherein the secondary source of steam comprises an auxiliary boiler and an auxiliary turbine. 
     
     
         9 . The plant of  claim 8 , further comprising a second controller configured to further regulate the rate of fuel to the auxiliary boiler in response to changes in the rate of fuel supplied to the boiler unit. 
     
     
         10 . The plant of  claim 1 , wherein the secondary source of steam comprises a steam saturator. 
     
     
         11 . The plant of  claim 10 , wherein the boiler unit comprises a secondary boiler loop that provides a flow of steam to the steam saturator. 
     
     
         12 . The plant of  claim 10 , wherein the power generation unit comprises a high pressure turbine, an intermediate pressure turbine, and a low pressure turbine, and the steam saturator receives one or more steam feeds from a steam feed group consisting of an intermediate pressure steam from an intermediate pressure steam feed from the high pressure turbine to the intermediate pressure turbine, a low pressure steam from a low pressure steam feed from the intermediate pressure turbine to the low pressure turbine, and a discharge pressure steam from a discharge steam line from the low pressure turbine. 
     
     
         13 . The plant of  claim 10 , wherein the controller control strategy that determines the flow rate of steam from the steam saturator to least one reboiler of the gas recovery unit is based on a plant load parameter by controlling the flow of steam from the boiler unit and the power generation unit to the steam saturator. 
     
     
         14 . A method for providing steam to a gas recovery unit, comprising:
 controlling the flow of steam to two or more regenerator columns of the gas recovery unit based on a load parameter for a power generation unit.   
     
     
         15 . The method of  claim 14 , wherein the flow of steam to the gas recovery unit is controlled by comparing the ratio of the rate of steam to the power generation unit to a rate of steam to a secondary source of steam to at least one reboiler of the gas recovery unit. 
     
     
         16 . The method of  claim 14 , wherein the flow of steam to the gas recovery unit is controlled by controlling a flow of steam to an auxiliary turbine in response to changes in steam flow to the power generation unit. 
     
     
         17 . The method of  claim 14 , wherein the flow of steam to the gas recovery unit is controlled by controlling a rate of fuel provided to a secondary source of steam that provides steam to the gas recovery unit based on the rate of fuel supplied to the power generation unit. 
     
     
         18 . The method of  claim 14 , wherein the flow of steam to the gas recovery unit is provided by controlling a flow of steam from a boiler unit to a steam saturator and from the power generation unit to the steam saturator. 
     
     
         19 . The method of  claim 14 , wherein the flow of steam to the gas recovery unit is controlled in response to changes in power generated by the power generation unit. 
     
     
         20 . The method of  claim 14 , wherein the control of steam to the gas recovery unit controls the temperature of two or more regenerator columns in the gas recovery unit.