DBC (double direct energy and quality balance coordinated control system) of secondary reheating uniflow boiler-steam turbine

Abstract

The invention discloses a realizing method of a coordinated control system of a secondary reheating uniflow boiler-steam turbine. The method realizes the dynamic decoupling control of a unit by use of a double direct energy-quality balance coordinated control system composed of an energy command signal of a secondary reheating steam turbine for the energy demand of a boiler and a heat signal and a ratio of fuel to water signal which respectively represent the energy and quality balance of the secondary reheating uniflow boiler. Meanwhile, the complex characteristic of the secondary reheating unit is considered, compensation links such as dynamic weighted compensation of heat of a characteristic point of the boiler, steam turbine pressure correction, asymmetric-constraint self-adaptive correction and the like are designed, and the regulating quality of thermal power plant units with secondary reheating is effectively increased.

Description

technical field [0001] The invention relates to a coordinated control system for unit units of a thermal power plant, in particular to a double reheat once-through boiler-steam turbine DBC coordinated control system based on a bidirectional direct energy-mass balance mechanism, belonging to the field of thermal automatic control. Background technique [0002] From the 1930s to the 1960s, Europe developed two patented once-through boiler technologies, namely the Benson once-through boiler and the Sulzer once-through boiler. At the same time, the Federal Republic of Germany, the United States, the former Soviet Union and other countries have successively built supercritical once-through boiler test benches and carried out a lot of experimental research work. The results found that not only the efficiency of supercritical units is higher, but supercritical steam also has certain advantages. Therefore, it attracted developed countries with rapid economic development, high power ...

AI Technical Summary

Problems solved by technology

[0021] Due to the use of double reheating, the structure and operation control of the unit are more complicated than those of the one-time reheating unit

From the control point of view, due to the obvious increase in the heat absorption share of boiler reheating, the volume lag of the heating surface and pipes of the secondary reheating part is significantly higher than that of the primary reheating unit. The output power of the unit accounts for more than 2 / 3 of the whole unit, and it is also possible to adopt a biaxial arrangement to form a unit structure similar to one furnace and two machines, so that the control characteristics of the unit have obvious differences compared with the one-time reheat unit. difference

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