Steam waste heat gradient utilization optimization control method

Abstract

The invention discloses a steam waste heat gradient utilization optimization control method. The method includes the following steps that: in a thermoelectric main steam loop, redundant steam is sentback to a boiler as feed water by means of the gradient working of a series-connected extraction / back-pressure steam turbine and a back-pressure steam turbine, so that a closed loop system is formed;a radial basis function neural network model is established, the steam turbine thermal load curve of the series-connected part is fitted through the radial basis function neural network; a boiler steam waste heat gradient utilization PID control model is established, a disturbance quantity is calculated on the basis of the thermal load curve, and is inputted into a fuzzy neural network for optimizing the disturbance quantity, and the disturbance quantity is fed back to be compared with the controlled quantities of the leading zone and inert zone of the boiler, improved PID control is used to complete the optimal control of boiler steam waste heat gradient utilization. According to the method, steam waste heat of different pressures and different temperatures is collected and utilized; steam temperature and pressure are automatically and smoothly controlled through the fuzzy neural network; and therefore, energy can be saved, emissions can be reduced, the comprehensive utilization of resources can be realized, and the power generation capacity of a power plant can be increased.

Description

technical field [0001] The invention relates to the fields of steam recovery, neural network and PID control, in particular to an optimal control method for cascade utilization of steam waste heat. Background technique [0002] In order to make full use of the waste heat of the steam after the superheated steam of the thermal power plant boiler is used for power generation, the thermal power plant usually replaces the traditional temperature and pressure reduction device with a back pressure steam turbine. The use of steam by industrial heat users on branch roads will inevitably produce heat load disturbances. The existing steam waste heat utilization control methods are mainly based on the reheat cycle of the steam Rankine cycle, regenerative steam extraction, and sintering waste heat recovery, etc. method, there are problems such as large fluctuations in steam temperature, unstable waste heat recovery efficiency, and poor automatic optimization performance of the system. A...

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Problems solved by technology

The use of steam by industrial heat users on branch roads will inevitably produce heat load disturbances. The existing steam waste heat utilization control methods are mainly based on the reheat cycle of the steam Rankine cycle, regenerative steam extraction, and sintering waste heat recovery, etc. method, there are problems such as large fluctuations in steam temperature and unstable waste heat recovery efficiency, and the automatic optimization performance of the system is poor. Although part of the steam recycling has been realized, there is still a lot of room for improvement in the recycling rate

On the other hand, when a large number of industrial heat loads are connected in parallel in the branch road, the existing control method cannot well ensure the stability of the main steam parameters

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