Machine algorithm-based turbine low-pressure cylinder exhaust enthalpy real-time calculation method

Abstract

The invention discloses a machine algorithm-based turbine low-pressure cylinder exhaust enthalpy real-time calculation method. According to the method, steam inlet parameters such as a unit load, mainsteam flow, a main steam pressure, a main steam temperature, and a steam inlet pressure and a steam inlet temperature of a medium-pressure cylinder and the like are selected as input variables; meanwhile, steam exhaust parameters such as a steam exhaust pressure and a steam exhaust temperature of a low-pressure cylinder and the like are selected as input variables; in addition, steam extraction parameters such as steam extraction pressures, steam extraction temperatures and the like of first to eighth stages of a turbine are selected as input variables; 28 parameters in total serve as the input variables; after data preprocessing, principal component analysis is performed to obtain n principal components with an accumulated contribution value greater than 99.95%; and by taking the n principal components as input variables of a BP neural network and taking an exhaust enthalpy of the turbine as an output variable, a turbine exhaust enthalpy calculation model based on a principal component analysis and neural network composite model is built; and by training the model, the turbine exhaust enthalpy calculation model is obtained, so that real-time calling in online monitoring is facilitated.

Description

technical field [0001] The invention belongs to the field of the power industry, and in particular relates to a real-time calculation method for the exhaust enthalpy of a low-pressure cylinder of a steam turbine based on a machine algorithm. Background technique [0002] Modern large-scale thermal power generation steam turbine units often require the economy of an online computer group. The calculation of the relative internal efficiency of the low-pressure cylinder is a major difficulty restricting the calculation of the efficiency of the steam turbine. The main reason is that the exhaust enthalpy of the low-pressure cylinder is difficult to calculate online. The exhaust steam of the low-pressure cylinder is different from the exhaust steam of the high-pressure cylinder and the medium-pressure cylinder. It is in the wet steam area and needs to be obtained from the wet steam dryness, saturated steam pressure, and saturated steam temperature. However, most units are not equip...

AI Technical Summary

Problems solved by technology

[0002] Modern large-scale thermal power generation steam turbine units often require the economy of an online computer group. The calculation of the relative internal efficiency of the low-pressure cylinder is a major difficulty restricting the calculation of the efficiency of the steam turbine. It is mainly due to the difficulty of online calculation of the exhaust enthalpy of the low-pressure cylinder.

The exhaust steam of the low-pressure cylinder is different from the exhaust steam of the high-pressure cylinder and the medium-pressure cylinder. It is in the wet steam area and needs to be obtained from the wet steam dryness, saturated steam pressure, and saturated steam temperature. However, most units are not equipped with low-pressure steam at present. On-line measurem

Images