Feed-forward Coal Feed Quantity Pre-control Method for Coal-fired Unit Boiler

A technology for coal-fired units and coal feeding amount, which is applied in the combustion method, adjusting fuel supply, controlling combustion, etc., can solve problems such as main steam pressure and load dynamic deviation, mismatch of pre-adding and subtracting coal feeding amount, etc. The effect of dynamic deviation, improving adaptability, and improving load control rate

Active Publication Date: 2017-12-22
ELECTRIC POWER SCI RES INST OF STATE GRID XINJIANG ELECTRIC POWER +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The present invention provides a feed-forward coal feed pre-control method for boilers of coal-fired units, which overcomes the deficiencies of the prior art, and can effectively solve the dynamic deviation between the main steam pressure and load and their respective set values ​​in the prior art and the mismatch of pre-addition and subtraction of coal feed due to changes in coal quality

Method used

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  • Feed-forward Coal Feed Quantity Pre-control Method for Coal-fired Unit Boiler
  • Feed-forward Coal Feed Quantity Pre-control Method for Coal-fired Unit Boiler
  • Feed-forward Coal Feed Quantity Pre-control Method for Coal-fired Unit Boiler

Examples

Experimental program
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Effect test

Embodiment 1

[0026] Embodiment 1: as attached figure 1 As shown, a coal-fired unit boiler feed-forward coal feed pre-control method includes the following steps:

[0027] The first step, the load triggers the signal: it is controlled by the switching module T1 whose difference between the target load instruction and the actual load is 0, and the data enters the pulse duration control function f after the switching selection 1 (x), pre-control coal feed function f 2 (x) input;

[0028] In the second step, the load performs a signal trigger pulse: f 1 (x) The output data is used to control the pulse duration, and the pulse signals are respectively output to three data switching modules T2, T6, T7 and the NOT gate;

[0029] In the third step, during the pulse period, the T2 output is controlled by the pre-control coal feed function f 2 The output of (x) is switched to 0, and the output of T2 is stored in In2;

[0030] In the fourth step, the ratio of the total fuel quantity to the actual...

Embodiment 2

[0042] Embodiment 2: As shown in Tables 1, 2, and 3, the function parameter setting is introduced by taking the 300MW subcritical drum boiler unit as an example below:

[0043] Overview of related equipment of the unit: the rated power of the unit is 300MW, and the boiler is coal-fired, subcritical, natural circulation, single steam drum, single furnace, four-corner tangential combustion, one-time intermediate reheating, and balanced boiler produced by Dongfang Boiler (Group) Co., Ltd. Ventilation, close-fitting, all-steel frame, solid slag discharge, pulverized coal furnace. The steam turbine is a subcritical, one-time intermediate reheat, high and medium pressure combined cylinder, single-shaft, double-cylinder, double-exhaust, heat-supply indirect air-cooled steam turbine manufactured by Dongfang Steam Turbine Co., Ltd. of Dongfang Electric Group.

[0044] As shown in Table 1, the pulse duration control function f 1 (x) The input (In) is the deviation (MW) between the targ...

Embodiment 3

[0051] Embodiment 3: As shown in tables 4, 5, and 6, taking the 350MW supercritical once-through furnace unit as an example, the parameter setting of the introduction function:

[0052] Overview of related equipment of the unit: The capacity of the unit is 350MW, and the boiler is a single furnace, balanced ventilation, solid slag discharge, all steel frame, full suspension structure, π-type, tight-fitting closed layout, and one-time intermediate reheat produced by Harbin Boiler Factory Co., Ltd. , Supercritical pressure variable pressure operation, a once-through boiler using an atmospheric expansion start-up system without a recirculation pump. The steam turbine is a supercritical, one-time intermediate reheat, indirect air-cooled double-cylinder double-exhaust condensing steam turbine manufactured by Dongfang Steam Turbine Co., Ltd.

[0053] As shown in Table 4, the pulse duration control function f 1 (x) The input (In) is the target and actual load deviation (MW), and the...

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Abstract

The invention relates to the technical field of boiler feedforward control of a control system, in particular to a pre-control method of boiler feedforward coal feed quantity of a coal-fired unit. The pre-control method comprises the following steps that first, signal trigger is conducted in a loaded mode; second, signal trigger pulsing is conducted in a loaded mode; third, during pulsing period, T2 is output to be stored into In2; fourth, T3 is output into In1, and after In1 and In2 are multiplied, the result is output into a speed limiting module to be input; fifth, the coal recovery rate is increased and decreased in advance to control the implement process; sixth, when T4 and T5 are not triggered, a fixed value A is the recovery speed of the later stage of increasing and decreasing in advance; and seventh, when pulsing is conducted in a loaded mode, signal trigger is switched to be at the speed B, T6 outputs a control limit descending speed value, and T7 outputs a control limit descending speed value. According to the pre-control method, the coal feed quantity is given beforehand when large loads of the coal-fired unit change, the loads change, main steam pressure is controlled rapidly and stably, the coordination control performance is improved, and an optimized effect is achieved.

Description

technical field [0001] The invention relates to the technical field of boiler feed-forward control in a control system, and relates to a coal-feeding pre-control method for boiler feed-forward of a coal-fired unit. Background technique [0002] The main task of the coordinated control system for coal-fired power generation units is to coordinate and control the two parameters of unit load and main steam pressure. The former is directly connected with the unit’s frequency and peak regulation, and load changes can be made in a timely manner according to the needs of the power grid; the latter is related to the stable operation of the boiler, and the main means of controlling the main steam pressure is the control of coal supply, because the energy conversion of boiler fuel has many links and the process is complicated , has the characteristics of large inertia and large time delay. Its control method is through the boiler coordinated PID and auxiliary multi-feedforward control...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): F23K3/00F23N1/00F23N5/00
CPCF23K3/00F23N1/002F23N5/00F23N2223/34F23N2239/02F23N2241/10
Inventor 孔德安徐强刘世军李建龙韩宏志王晓宇刘江山
Owner ELECTRIC POWER SCI RES INST OF STATE GRID XINJIANG ELECTRIC POWER
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