Hot steam re-extraction heat supply control system and method coupled with pressure matcher

Abstract

The invention discloses a hot steam re-extraction heat supply control system and method coupled with a pressure matcher. A multi-nozzle needle valve is coupled to control the pressure matcher, and the flow and pressure of an outlet of the pressure matcher are adjusted by adjusting the opening of the needle valve; meanwhile, two controllers which are connected in series to work are selected to form a double-closed-loop control system, an auxiliary controller is used for performing advanced control on desuperheating water interference, and the influence of the desuperheating water interference on the outlet steam temperature is reduced; and meanwhile, according to a double-closed-loop system, temperature setting feedforward of driving steam is obtained in advance, the disturbance influence caused by parameter changes of the driving steam and suction steam due to working condition changes of a unit can be weakened, and control is more accurate. The problems that the delay of the outlet steam temperature of the pressure matcher and the time constant are very large, the interference effect of desuperheating water is strong and frequent, and the parameter change of driving / suction steam due to the change of working conditions is difficult to accurately control are solved.

Description

technical field [0001] The invention relates to the field of automatic control of steam extraction and heat supply systems of thermal power units, in particular to a thermal re-extraction and heat supply control system and method coupled with a pressure matcher. Background technique [0002] With the rapid development of my country's economy and industry, the amount of industrial steam and residential steam consumption has also increased. Cogeneration of coal-fired units is still one of the important ways to meet the current steam load. At the same time, with the deepening and improvement of my country's electric power system reform and energy conservation and emission reduction policies, power generation companies must not only ensure safe production, but also have more urgent requirements for unit operation economy in the market opening and competition of online bidding. Therefore, how to effectively It is the current research focus of heating technology to reduce the heat ...

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Problems solved by technology

[0007] In order to solve the above-mentioned problems in the prior art, the present invention proposes a heat re-extraction heat supply control system and method coupled with a pressure matcher. The present invention uses a multi-nozzle needle valve to control the outlet pressure and flow rate of the pressure matcher, which can The steam flow can be automatically controlled within a large range, and the contradiction that the flow of the pressure matcher cannot be adjusted is solved; the cascade control method is used to control the steam temperature at the outlet of the pressure matcher, which is composed of two serially connected controllers. The double closed-loop control system uses the sub-controller to control the interference of the desuperheating water in advance, reducing the influence of the interference on the outlet steam temperature, and solving the problem that the lag and time constant of the outlet steam temperature of the pressure matcher are large, and the interference of the desuperheating water is strong and frequent. Control precise puzzles

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