BP (Back Propagation) neural network-based exhaust dryness computing method of USC (Ultra-Supercritical) turbine

Abstract

The invention provides a BP (Back Propagation) neural network-based exhaust dryness computing method which aims at the problem of online computing the exhaust dryness of a large-scale USC (Ultra-Supercritical) unit in domestic. The BP neural network-based exhaust dryness computing method is characterized in that the exhaust dryness of a turbine under different working conditions can be computed by using a heat balance diagram of a real USC unit under different unit loads and different exhaust pressure working conditions as a basis, the exhaust dryness of the turbine can be finally, quickly and actually computed by utilizing a BP artificial neural network after a computing result is subjected to certain data processing, the obtained computing result is very close to an actual running value of the turbine, the computing accuracy is ideal, the model structure is simple, the computing is rapid, the purpose of online computing the exhaust dryness of the turbine under the real working condition can be achieved, an abnormal phenomenon of the exhaust dryness is prevented from happening, an operating person can be helped knowing the running state of the USC unit, and safe and economic running of the turbine can be maintained.

Description

technical field [0001] The invention relates to a method for calculating the dryness of exhaust steam of an ultra-supercritical steam turbine, in particular to a method for calculating the dryness of exhaust steam of an ultra-supercritical steam turbine based on a BP neural network. Background technique [0002] The economy and safety of the operation of large ultra-supercritical steam turbine units depend to a large extent on the operating conditions of the cold end system of the steam turbine. The loss of moisture in the last few stages of the steam turbine becomes larger, which affects the thermal economy of the steam turbine. In addition, too low exhaust steam dryness will cause erosion of the surface of the blades of the last few stages of the steam turbine, and even cause the blades to break, which seriously affects the safety of the steam turbine operation. [0003] In actual thermal power plants, there are generally two ways to obtain the exhaust air dryness value: m...

AI Technical Summary

Problems solved by technology

Among them, the measurement method is generally not high in accuracy, and the calculation method is complicated, and they are not suitable for the online calculation of the exhaust steam dryness of modern large-scale ultra-supercritical units.

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