Realization method of decentralized control system for self-balancing control loop of supercritical boiler coal calorific value

Abstract

The invention discloses a method for realizing a decentralized control system of a self-balancing control loop for coal-fired calorific value of a supercritical boiler. The machine speed command; the total coal volume command after the calorific value correction is the total coal volume command output after the dynamic actual measured coal supply and the calorific value balance correction coefficient are multiplied; the calorific value balance correction coefficient is a delay Calorific value balance correction coefficient of . Based on the DCS platform of the unit, the present invention can realize the soft measurement of the calorific value of coal without adding additional capital investment. The soft measurement signal of the calorific value of coal can facilitate the real-time monitoring of the coal quality of the coal into the furnace by the operator, guide the adjustment of the boiler combustion, and design based on this A coal-fired calorific value self-balancing control loop enables the unit coordination control system to have the ability to adapt to changes in multiple coal types, improving the unit's operational stability and economy.

Description

technical field [0001] The invention belongs to the thermal engineering measurement field of a thermal power plant, and in particular relates to a method for realizing a decentralized control system (DCS) of a self-balancing control loop of a supercritical boiler coal-fired calorific value. Background technique [0002] At present, power plant boilers have various coal sources and seriously deviate from the designed coal types. In order to reduce fuel costs, power generation companies continue to increase coal blending efforts. Affected by factors such as blending sites and blending plans, coal blending and blending The uniformity is difficult to be effectively controlled, and the calorific value of the furnace coal changes frequently, which affects the coordinated control performance of the unit, and even brings hidden dangers to the safe operation of the boiler. [0003] In the direct energy balance coordinated control scheme of the drum boiler, the heat signal represents ...

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Problems solved by technology

However, supercritical once-through boilers have small energy storage and cannot construct heat signals similar to drum boilers. In its indirect energy balance coordinated control scheme, fuel calorific value disturbances are usually corrected by closed-loop main steam pressure. This passive correction method eliminates deviations Weak, especially in the condition of AGC with continuous and large load changes, the accumulated deviation will lead to long system stabilization time and large fluctuations in unit operating parameters

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