Control method and system model for steam turbine medium-pressure regulating valve to participate in secondary frequency modulation

Abstract

The invention discloses a control method and a system model for a steam turbine medium-pressure regulating valve to participate in secondary frequency modulation. The control method comprises the following steps that, when a supercritical unit stably operates under a given working condition, a medium-pressure regulating valve and a high-pressure regulating valve are regulated to preset opening degrees; when the unit load step is increased, the opening degrees of the high-pressure regulating valve and the medium-pressure regulating valve are increased; when the unit load step is reduced, the opening degrees of the high-pressure regulating valve and the medium-pressure regulating valve are reduced, and the high-pressure regulating valve and the medium-pressure regulating valve jointly participate in unit load response; after the load response is finished, the high-pressure regulating valve and the medium-pressure regulating valve are both recovered to the preset opening degrees; and the low-limit opening degree of the medium-pressure regulating valve is 23%-38%, and the valve mileage, participating in load regulation, of the medium-pressure regulating valve is 62%-77%. According to the control method, the high-pressure regulating valve and the medium-pressure regulating valve jointly participate in secondary frequency modulation load response, load response speed and precision are improved, the load response time is shortened, and the secondary frequency modulation performance of a supercritical unit is improved.

Description

technical field [0001] The invention relates to the technical field of frequency modulation, in particular to a control method and a system model for a medium-voltage regulating valve of a steam turbine participating in secondary frequency modulation. Background technique [0002] Climate change is a global problem facing mankind. As countries emit carbon dioxide, greenhouse gases soar, posing a threat to living systems. In this context, countries around the world have agreed to reduce greenhouse gas emissions, and my country has proposed the goals of carbon peaking and carbon neutrality. Developing a low-carbon economy and reshaping the energy system are important means to achieve the above goals. [0003] The development trend of new energy has changed the energy structure and further caused the problem of energy consumption. As far as the current situation is concerned, the healthy and sustainable development of the power industry has been restricted. Therefore, encouragi...

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Problems solved by technology

[0004] Among them, although the factory-side coordinated control logic optimization optimizes the coordination logic algorithm to a certain extent, and uses a more streamlined or advanced algorithm to improve the response rate of the load, it cannot avoid the inertia and large hysteresis characteristics brought by the boiler itself. A series of problems such as non-linear characteristics; secondly, the control of supercritical units at the present stage mainly adopts the method of conventional PID plus feed-forward. Speed ​​and accuracy; In addition, improving the speed of load response is also at the expense of the safe and stable operation of the equipment to a certain extent

[0005] The construction of charging and discharging energy storage units can not only greatly improve the load response rate of the unit unit, but also solve the inherent characteristics of the equipment itself and the multivariable nonlinear factors. It is not high. This method can be used for the construction of new power plants. In addition to capital investment, there are still a series of problems in the built power plants such as the space layout of the power plant.

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