The method of suppressing high exhaust temperature of high pressure cylinder in fcb process

Abstract

The invention discloses a method for suppressing a high exhaust temperature of a high-pressure cylinder in an FCB process. The method is applicable to the case that a steam turbine is under an intermediate-pressure cylinder start manner after FCB action, and comprises the following steps: acquiring the rotational speed of the steam turbine and the opening degree of a medium-pressure control valveof the steam turbine in real time; when the rotational speed of the steam turbine is less than a rated rotational speed, and the opening degree of the medium-pressure control valve is greater than a set opening degree value, controlling at least one high-pressure control valve to be opened at a predetermined speed and controlling a vent valve of the high-pressure cylinder to be opened, and reducing the opening degree of the medium-pressure control valve; detecting the rotational speed of the steam turbine, and the opening degrees of the high-pressure control valve and the medium-pressure control valve in real time; and when the opening degree of the high-pressure control valve reaches a preset target value or the opening degree of the medium-pressure control valve is reduced to reach a preset stable opening degree value, controlling the high-pressure control valve to keep a current opening degree state, and controlling the rotational speed of the steam turbine approximately to be the rated rotational speed by the medium-pressure control valve. According to the method, a part of steam is enabled to pass through the high-pressure cylinder to bring away the air-blasting heat of the high-pressure cylinder by properly opening the high-pressure control valve, so that control over the exhaust temperature of the high-pressure cylinder is realized, and simple and reliable control is achieved.

Description

technical field [0001] The invention relates to the field of automatic control of thermal power generating sets, in particular to a method for suppressing the high exhaust temperature of a high-pressure cylinder in an FCB process. Background technique [0002] With the expansion of power grid capacity, countries around the world are paying more and more attention to the safety of power grid operation, and the FCB function of generator sets is an important measure to ensure the safe and stable operation of power grids and units; The realization of FCB function is not considered. If it is to realize the FCB function on the basis of the existing unit, the technical difficulty is relatively large; especially since the high-pressure cylinder does not enter steam after the FCB operation, long-term blast friction will cause the exhaust temperature of the high-pressure cylinder to be too high , affecting the safety of the unit, so the unit cannot maintain low-load operation for a lo...

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Problems solved by technology

[0004] When controlling the exhaust temperature of a pair of high-pressure cylinders, the exhaust temperature of the high-pressure cylinder may reach the protection action value in a short time (about 30 minutes in practice), but the external environment or internal faults of the unit usually cannot Eliminate or restore in a short time, the short time after FCB action is not conducive to the unit to resume normal operation, and the effect of FCB will be greatly reduced; when controlling the exhaust temperature of the high-pressure cylinder through method 2, it needs to be restored in a short time after the FCB action is normal It requires the external environment to be normal and the internal unit to be free of faults. After the FCB operates, on-site confirmation is required. The on-site confirmation usually takes more than 30 minutes, that is, the second method must be carried out under the condition of pre-judgment and preparation.

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