Systems and methods for control of volumetric flows in a power production plant
The present disclosure provides methods for controlling volumetric flows of streams into a combustor, and particularly in a combustor utilized in a power production method. A controller can be used to receive a variety of inputs, carry out calculations, and output one or more signals that adjust one or more parameters of one or more of the streams entering the combustor. Such adjustments can be effective to normalize a volumetric flow rate between the combustor and a turbine immediately downstream from the combustor without requiring direct measurement of the volumetric flow rate between the combustor and the turbine immediately downstream from the combustor.
1 . A method for power production, the method comprising:
passing a plurality of streams into a combustor so that a fuel is combusted with an oxidant in the combustor in the presence of a carbon dioxide diluent to form a combustor exhaust stream;
expanding the combustor exhaust stream in a turbine to generate power at a desired output and provide a turbine exhaust stream;
processing the turbine exhaust stream to isolate carbon dioxide therefrom and provide the carbon dioxide diluent;
calculating a factor effective for normalizing a total volumetric flow rate of the plurality of streams into the combustor, such that the total volumetric flow rate varies by no more than 10% as the desired output of power generated by the turbine increases or decreases; and
modifying a chemistry of at least one of the plurality of streams passing into the combustor as the desired output of power generated by the turbine increases or decreases based on the calculated factor effective for normalizing the total volumetric flow rate-of the plurality of streams into the combustor.
2 . The method of claim 1 , wherein modifying the chemistry of the at least one of the plurality of streams passing into the combustor includes inputting to a controller one or more control inputs indicative of the increase or decrease in the desired output of power generated by the turbine.
3 . The method of claim 1 , wherein passing the plurality of streams into the combustor includes passing a fuel stream into the combustor, and wherein modifying the chemistry of the at least one of the plurality of streams passing into the combustor includes inputting to a controller a signal corresponding to a mass flow of the fuel stream at a point that is immediately upstream of an inlet of the fuel stream to the combustor.
4 . The method of claim 3 , wherein modifying the chemistry of the at least one of the plurality of streams passing into the combustor includes outputting from the controller a signal effective to increase or decrease a flow of the carbon dioxide diluent into the fuel stream upstream from the combustor.
5 . The method of claim 1 , wherein passing the plurality of streams into the combustor includes passing an oxidant stream into the combustor, and wherein modifying the chemistry of the at least one of the plurality of streams passing into the combustor includes inputting to a controller a signal corresponding to a pressure of the oxidant stream at a point that is immediately upstream of an inlet of the oxidant stream to the combustor.
6 . The method of claim 5 , wherein modifying the chemistry of the at least one of the plurality of streams passing into the combustor includes outputting from the controller a signal effective to increase or decrease a flow of the carbon dioxide diluent into the oxidant stream upstream from the combustor.