Method and device for regulating and controlling steam turbine variable pressure operation

Abstract

The invention relates to the field of power generation and particularly relates to a variable-pressure operation regulation control method and device of a steam turbine. The method comprises the following steps: comparing main steam pressure P0 with a low pre-set value PL of steam inlet pressure of the steam turbine and a high pre-set value pH (Potential of Hydrogen) of the steam inlet pressure of the steam turbine; when the main steam pressure P0 is between the low pre-set value PL of the steam inlet pressure of the steam turbine and the high pre-set value pH of the steam inlet pressure of the steam turbine, adopting a variable-pressure operation control mode, and automatically controlling a pre-set value FSet from a valve position F of a steam inlet valve to a corresponding pre-set valve position when the specific power of the steam turbine is maximum; when the main steam pressure P0 is smaller than the low pre-set value PL of the steam inlet pressure of the steam turbine, adopting a pressure low-limit control mode and automatically controlling the steam inlet valve to be turned down; and when the main steam pressure P0 is greater than the high pre-set value pH of the steam inlet pressure of the steam turbine, adopting a pressure high-limit control mode and automatically controlling the steam inlet valve to be turned on. The variable-pressure operation regulation control method and device of the steam turbine have the beneficial effects that steam energy is sufficiently utilized and the steam turbine can work more safely; and the operation economical efficiency is the highest.

Description

technical field [0001] The invention relates to the field of power generation, in particular to a method and device for adjusting and controlling steam turbine pressure-variable operation. Background technique [0002] At present, large-scale generating sets (such as rated power of 150MW and above) all adopt "electronic cam steam distribution mechanism", that is, each steam inlet valve is controlled by an oil motor, and "sequential valve" control can be realized through the control system, with 4 inlet valves. Taking the steam valve as an example, you can open valves 1 and 4 first, then valve 3, and finally valve 4, which is much smaller than the throttling loss of opening 4 valves at the same time. The steam inlet mode of this type of unit can be modified and selected through the control system, and generally adopts the "unit system" operation mode, that is, one machine and one boiler operation, the steam inlet parameters are relatively stable, and generally operate under r...

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Problems solved by technology

The constant power control method only considers the stability of the output power of the unit, and has a great influence on the change of the inlet steam parameters, so it is rarely used in the steam energy waste heat utilization occasions

[0009] (3) The sliding pressure operation control method is to fully open the regulating valve of the steam turbine to ensure that all the steam enters the steam turbine. This method can make full use of the steam energy generated by the upstream process. When the inlet steam pressure is lower than the minimum safe inlet steam pressure allowed by the steam turbine, it will affect the safe operation of the steam turbine

[0010] The above control methods do not consider the optimal operating efficiency point of the unit

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