Condensate flow rate control device and condensate flow rate control method for power plant

A condensate flow rate control method for a power plant, the power plant having:

• a boiler;
• a steam turbine configured such that steam generated by the boiler is introduced thereinto;
• a generator configured to be driven by the steam turbine;
• a condenser configured such that exhaust hot steam from the steam turbine is supplied thereto;
• a deaerator water level adjustment valve;
• a deaerator configured such that condensate generated by the condenser is supplied via the deaerator water level adjustment valve thereto and bleed steam from the steam turbine is introduced thereinto;
• and
• a feed pump configured to supply feedwater deaerated by the deaerator to the boiler,
• the method comprising:
• conducting condensate flow rate control with a water level adjustment unit by inputting a frequency fluctuation or a requested load change into the water level adjustment unit, and the water level adjusting unit adjusting pressure in a condensate flow path from the deaerator water level adjustment valve to the deaerator and thereby adjusting an amount of bleed steam from the steam turbine so that the inputted frequency fluctuation is suppressed or an output value of the generator conforms to the inputted requested load change,
• wherein based on a preset relationship between a fluctuation width of a frequency fluctuation or a change width of a requested load change and a change width of a water level or a holding water amount of the deaerator, a setting value of the water level or a setting value of the holding water amount is calculated from the frequency fluctuation or the requested load change, and an opening instruction is outputted to the deaerator water level adjustment valve so that the water level or the holding water amount of the deaerator assumes the setting value of the water level or the setting value of the holding water amount as the condensate flow rate control;
• displaying at least one estimated value of a fluctuation width of a frequency fluctuation or a change width of a requested load change which is estimated to be inputted, and computing a remaining number of times the water level adjustment unit can conduct the condensate flow rate control based on the estimated value, a detected value of a water level or a holding water amount of the deaerator, and a lower limit of the water level or the holding water amount of the deaerator;
• and
• displaying the remaining number of times computed in association with the estimated value.

A power plant comprising:

• a boiler:
• a steam turbine configured such that steam generated by the boiler is introduced thereinto;
• a generator configured to be driven by the steam turbine;
• a condenser configured such that exhaust hot steam from the steam turbine is supplied thereto;
• a deaerator water level adjustment valve;
• a deaerator configured such that condensate generated by the condenser is supplied via the deaerator water level adjustment valve thereinto and bleed steam from the steam turbine is introduced thereinto;
• a condensate flow path extending from the deaerator water level adjustment valve to the deaerator configured such that the condensate is supplied to the deaerator therethrough;
• a feed pump configured to supply feedwater deaerated by the deaerator to the boiler;
• and
• a condensate flow rate control device comprising a water level adjustment unit configured to perform condensate flow rate control such that a frequency fluctuation or a requested load change is inputted into the water level adjustment unit and the water level adjustment unit adjusts pressure in the condensate flow path and thereby adjusts an amount of bleed steam from the steam turbine so that the inputted frequency fluctuation is suppressed or an output value of the generator conforms to the inputted requested load change,
• wherein based on a preset relationship between a fluctuation width of a frequency fluctuation or a change width of a requested load change and a change width of a water level or a holding water amount of the deaerator, the water level adjustment unit is configured to calculate a setting value of the water level or a setting value of the holding water amount from the frequency fluctuation or the requested load change and output an opening instruction to the deaerator water level adjustment valve so that the water level or the holding water amount of the deaerator assumes the setting value of the water level or the setting value of the holding water amount;
• an allowable control count calculating unit configured to display at least one estimated value of a fluctuation width of a frequency fluctuation or a change width of a requested load change which is estimated to be inputted and compute a remaining number of times the water level adjustment unit can conduct the condensate flow rate control based on the estimated value, a detected value of a water level or a holding water amount of the deaerator, and a lower limit of the water level or the holding water amount of the deaerator;
• and
• a display unit configured to display the remaining number of times computed by the allowable control count calculating unit in association with the estimated value.