Method of calculation of energy characteristics heat turbines taking into account the economy of the low pressure flow part

Abstract

Thermal power plants require regular review of regulatory energy performance. Data sources for this can be the results of thermal tests or typical energy characteristics of units. The first way is costly, the second only partially allows taking into account the technical condition of the equipment. An urgent task is to develop a methodology for constructing energy characteristics that would make it possible to solve this problem with reasonable accuracy and using minimal resources. Such conditions are met by the existing methodology for determining the energy characteristics of turbines which is based on the methodology of matrix formalization of the calculation of energy-mass-exchange plants. The technique has been tested in relation to turbines with one-stage heat recovery. The aim of this study is to increase the accuracy of the calculation using the developed methodology for the energy characteristics of turbines with two-stage heat recovery. The turbine installation is simulated within the framework of the matrix formalization methodology using the equations of mass and energy balances solved by mathematical programming methods. The energy charac-teristics of the equipment are determined in accordance with the existing regulatory approach. The methodology for determining the energy characteristics of turbine plants developed in the framework of the matrix formalization meth-odology has been extended to the case of calculating steam turbines with two-stage heating selection by taking into account the dependence of the efficiency indicators of the low-pressure flow part on the position of the control diaphragm for different modes of heating network water. The results of test calculations with reasonable accuracy coincided with the energy characteristics of the operating turbine. For modes with one- and two-stage heating of network water, it is advisable to use different methods of accounting for the efficiency indicators of the low-pressure flow part. In this case, the introduction of the dependence of the internal relative efficiency of the low pressure part on the relative volumetric steam flow into the model for the regime with two-stage heating of network water allows achieving accuracy acceptable for solving practical problems.