High-quality steam temperature control system for power station boiler

Abstract

The invention provides a high-quality steam temperature control system for a power station boiler. A leading segment steam specific enthalphy signal is used as a quick loop feedback signal in the double-loop steam temperature control system, and the control logic of the leading segment steam specific enthalphy feedback loop part of the system is that a leading steam temperature feedback value signal and a leading segment steam pressure feedback value signal obtained after one-order inertia smoothing is conducted are input into a steam specific enthalphy computing module at the same time, the leading segment steam specific enthalphy signal is worked out through the steam specific enthalphy computing module, and then the leading segment steam specific enthalphy signal is used as the quick loop feedback signal in replacement of a leading steam temperature signal to be introduced into the steam temperature control system. According to the high-quality steam temperature control system for the power station boiler, the leading segment steam specific enthalphy replaces the leading steam temperature and serves as the quick loop feedback signal, the problems of reduction of the steam temperature control quality caused by overheat and reheat under the large-amplitude high-speed variable-load working condition of a thermal power generating unit are solved, and the function of stabilizing the steam pressure of the boiler can be played. Furthermore, the high-quality steam temperature control system for the power station boiler has the beneficial effects of being easy to configure and debug and the like.

Description

technical field [0001] The invention relates to a steam temperature control system for a power plant boiler using the specific enthalpy of steam in a leading area as a feedback signal, and belongs to the technical field of boilers. Background technique [0002] Large-scale utility boilers control the temperature of superheated and reheated steam by spraying water to reduce the temperature. Because the controlled object has large inertia and large delay characteristics, the control system mostly adopts dual-circuit steam temperature control systems such as cascade or leading differential. Compared with the single-loop steam temperature control system, the cascade or leading differential control adds a leading area signal that can quickly reflect the change of the control input signal. To distinguish, the controlled signal is also called the inert zone signal. Take cascade steam temperature control as an example, such as figure 1 As shown, the control system includes inner a...

AI Technical Summary

Problems solved by technology

Therefore, for the superheated steam temperature control system, when the desuperheating water flow rate changes greatly, the gain of the inert zone of the steam temperature object will change significantly, which will affect the control quality

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