Power plant and power output increase controlling method for power plant
A power plant comprises a boiler, a turbine, a condenser, a feed water heater, a deaerator, a deaerator water level control valve, an extraction system which introduces the steam extracted from the turbine into the feed water heater, an extraction valve, an auxiliary steam introduction system which introduces auxiliary steam into the feed water heater, an auxiliary steam control valve and a control device. When a rapid load increase request is made, the control device controls, to orient the extraction valve in a closing direction, to maintain an opening of the deaerator water level control valve, and to orient the auxiliary steam control valve in an opening direction.
1. A power plant, comprising:
a steam generation device;
a turbine which is driven with stream generated by the steam generation device;
a condenser which condenses the steam exhausted from the turbine;
a feed water heater which heats condensate whose pressure is risen by a condensate pump;
a deaerator which heats and de-aerates the condensate heated by the feed water heater;
a deaerator water level control valve which controls a water level of the deaerator;
an extraction system which introduces the steam extracted from the turbine into the feed water heater;
an extraction valve installed in the extraction system;
an auxiliary steam introduction system which introduces auxiliary steam into the feed water heater;
an auxiliary steam control valve which is installed in the auxiliary steam introduction system and controls an amount of steam supplied to the feed water heater; and
a control device which outputs opening command signals to the deaerator water level control valve, the extraction valve, and the auxiliary steam control valve,
wherein the control device controls to orient the extraction valve in a closing direction, controls to maintain an opening of the deaerator water level control valve, and controls to orient the auxiliary steam control valve in an opening direction in a case where a rapid load increase request is made to the power plant.
2. The power plant according to claim 1 , wherein a desuperheater for the auxiliary steam is installed in an auxiliary steam supply pipe of the auxiliary steam introduction system.
3. The power plant according to claim 1 , wherein a pressure reducer for the auxiliary steam is installed in an auxiliary steam supply pipe of the auxiliary steam introduction system.
4. The power plant according to claim 1 , further comprising a pressure gauge which is configured to measure a pressure in the feed water heater, and
wherein the control device controls an opening of the auxiliary steam control valve with the pressure in the feed water heater set as a control index.
5. The power plant according to claim 1 , further comprising a flowmeter which is configured to measure a flow rate of extracted steam which flows in the extraction system, and
wherein the control device controls an opening of the auxiliary steam control valve with the flow rate of the extracted steam set as a control index.
6. A power output increase controlling method for a power plant which includes a steam generation device, a turbine which is driven with stream generated by the steam generation device, a condenser which condenses the steam exhausted from the turbine, a feed water heater which heats condensate water whose pressure is risen by a condensate pump, a deaerator which heats and de-aerates the condensate heated by the feed water heater, a deaerator water level control valve which controls a water level of the deaerator, an extraction system which introduces the steam extracted from the turbine into the feed water heater, an extraction valve which is installed in the extraction system, an auxiliary steam introduction system which introduces auxiliary steam into the feed water heater, and an auxiliary steam control valve which is installed in the auxiliary steam introduction system and controls an amount of steam supplied to the feed water heater, comprising the step of controlling to orient the extraction valve in a closing direction, controlling to maintain an opening of the deaerator water level control valve, and controlling to orient the auxiliary steam control valve in an opening direction in a case where a rapid load increase request is made to the power plant.
7. The power output increase controlling method for the power plant according to claim 6 , further comprising the steps of:
measuring a pressure in the feed water heater; and
controlling an opening of the auxiliary steam control valve with the pressure in the feed water heater set as a control index.
8. The power output increase controlling method for the power plant according to claim 6 , further comprising the steps of:
measuring a flow rate of extracted steam which flows in the extraction system; and
controlling an opening of the auxiliary steam control valve with the flow rate of the extracted steam set as a control index.