Thermal power unit sliding pressure optimizing and regulating system and method

Abstract

The invention discloses a thermal power unit sliding pressure optimizing and regulating system and method. The system comprises a PLC control unit, a distributed control system, a plurality of steam turbine septum valves, a variable-frequency condensate pump and a deaerator level control valve, wherein the distributed control system is connected with the PLC control unit through a two-way interface, the steam turbine septum valves are connected with the distributed control system, and the PLC control unit is used for achieving system parameter and signal reading through the distributed control system and achieving control over main steam pressure, the variable-frequency condensate pump and the deaerator level control valve. By means of the thermal power unit sliding pressure optimizing and regulating system and method, time-consuming and labor-consuming unit operation optimizing experiments and calculation are avoided, a set target of the main steam pressure can be dynamically optimized in real time according to environment changes, contradiction between main steam pressure optimizing capacity and load regulating capacity is avoided through the energy storage and regulation function of a condensate system, and the maximization of operating economy of a generator unit is dynamically achieved in real time under the premise that requirements of a power grid are met.

Description

technical field [0001] The invention relates to the technical field of thermal power generation unit control, in particular to a thermal power unit sliding pressure optimization adjustment system and an adjustment method. Background technique [0002] The actual operating energy consumption of thermal power units in my country is generally much lower than the design energy consumption of the units. On the one hand, long-term operation under partial load conditions makes the operating conditions of the units seriously deviate from the most economical design conditions; on the other hand, my country's relatively high The peak-to-valley ratio of power consumption makes the power grid require most units to participate in load regulation, retaining the ability to quickly raise and lower loads, and further sacrificing the operating economy of the units. [0003] The typical unit adjustment operation mode can be divided into two types: constant pressure operation and sliding pressur...

AI Technical Summary

Problems solved by technology

[0005] 1. The determination of the optimization curve depends on high-precision calculations and experiments on the operating economy of the entire power station, which requires more manpower and equipment resources, and the implementation cost is high

[0006] 2. The calculation result of the optimal sliding pressure operation curve tends to adopt a lower main steam pressure at a lower load, which will inevitably reduce the energy storage level of the unit under lower load conditions to a large extent , resulting in a significant drop in the unit's primary frequency regulation and AGC load regulation capabilities

In order to meet the requirements of grid-connected power generation of generator sets, it is necessary to ensure the adjustment ability of primary frequency regulation and AGC. Therefore, the sliding pressure operation curve finally set by the actual unit often floats up the theoretically calculated optimal sliding pressure curve to improve the unit’s performance. The actual operating main steam pressure greatly discounts the relevant optimization results

[0007] 3. The theoretical optimal sliding pressure operation curve is not unique, and it changes with the changes of parameters such as ambient pressure, circulating water temperature, and unit back pressure. The standard sliding pressure curve calculated according to the rated parameters is often used in actual operation. It deviates from the theoretical optimal point, especially for the northern inland areas where the four seasons and the diurnal environment change greatly, the deviation is even greater

Relevant corrections based on changes in environmental and working condition parameters are often only qualitative, and it is difficult to obtain quantitative corrections with engineering accuracy

[0008] To sum up, first of all, it is difficult to obtain the theoretically optimal sliding pressure curve, and in order to meet the requirements of the power grid for the unit, the optimal calculation curve cannot be directly implemented; secondly, the actual optimal sliding pressure curve varies with the environment and working condition parameters The curve optimization method based on the traditional technical route has large control deviation and insufficient energy saving effect; thirdly, this method has obvious correlation with multiple control subsystems of the unit. When the unit optimizes, adjusts and transforms related systems After that, the original optimization curve becomes invalid, and the optimization process needs to be carried out frequently

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