Optimized boiler control system and method based on integral parameter dynamic adjustment

Abstract

The invention discloses an optimized boiler control system and method based on integral parameter dynamic adjustment. The system comprises a signal acquisition module, a segmented function module, ananalog quantity selector, a subtracter, a hysteresis module, a high-low limit alarm module, a hysteresis setting timer and a boiler main controller, wherein the input end of the signal acquisition module is connected with a machine set, and the first output end is connected with the second input end of the analog quantity selector through the segmented function module, the second output end is connected with the first input end of the subtracter, the third output end is connected with the second input end of the subtracter through the hysteresis module, the output end of the subtracter is connected with the setting end of the analog quantity selector sequentially via the high-low limit alarm module and the hysteresis setting timer, and the output end of the analog quantity selector is connected with the integral parameter setting end of the boiler main controller. The coordination action of a boiler of a machine set and a steam turbine is achieved, the performance of the frequency modulation and peak regulation of the machine set is improved, and the frequency fluctuation of a power grid system is reduced.

Description

technical field [0001] The invention relates to the field of boiler optimization control, in particular to a boiler optimization control system and method based on dynamic adjustment of integral parameters. Background technique [0002] With the development of material technology and the continuous improvement of energy-saving requirements, large-scale thermal power units, especially supercritical and ultra-supercritical large-scale units, have been more and more widely used in domestic power supply construction. Nowadays, due to the influence of macro factors, large-capacity units all adopt variable load operation, frequency regulation and peak regulation, and the daily load changes in a wide range. Under the new situation of UHV power grid interconnected with large regional power grids, all levels of power grids are increasingly connected, and the requirements for coordination between power grids and generators are also getting higher and higher. AGC in the grid source coo...

AI Technical Summary

Problems solved by technology

However, due to the inherent hysteresis of boiler side combustion, and the longer combustion period caused by denitrification and low-nitrogen combustion transformation in recent years, when the AGC load command changes, it is common for units to change from boiler control command to coal quantity change, combustion The cycle of doing work is much longer than the time required for load adjustment on the steam turbine side. That is to say, during a certain adjustment process, there will be AGC load commands that have changed. If the adjustment direction has been reversed, the boiler side will change the last load command. The required energy is released to form an inverse regulation of both the boiler side and the steam turbine side

At the same time, in actual operation, it is found that the coal feeder or powder feeder of the unit has inconsistent coal or powder feed capacity in different operating ranges, which will also cause a mismatch between pressure and load adjustment.

However, due to the development of large-scale AC and DC long-distance power transmission, the power grid has higher requirements on the AGC adjustment rate, which requires an acceleration of the load adjustment rate on the steam turbine side of the unit, resulting in increased main steam pressure fluctuations, and further aggravates the time mismatch between the boiler side and the turbine side. The problem will bring a certain negative impact on the stability of unit coordinated operation and the accuracy of load control, which in turn will affect other performance indicators such as the assessment of the dispatching control department.

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