Thermal Economy Model Analysis For Thermal Power Unit

With the development of power market and competition of power grid price, the management goal of power plant has changed from ensuring to run in a safe and stable way in the long-term to demanding the unit to participate in peak modulation, frequency modulation in depth and ensure the unit to run in a safe and economic mode. Thermal power unit performance calculation and performance analysis are of important significance to guide operator of power plant, optimizing operation, safe and economic operation and realize saving energy and reducing consumption. In this paper, based on the thermal economic state equation,combining with steam-water distribution equation, steam turbine output internal power equation, and boiler medium heat equation of thermodynamic system, making use of the idea of matrix analysis, analyzed thermal economy model for thermal power unit.In this paper, the mathematical model for the thermal economy entire calculation of desuperheater water systeml is introduced in details, when the desuperheating water for the boiler’s superheater and reheater have separate sources. By this model, the300MW unit was calculated and simulated by the LabVIEW to verify not only the validity of this method, but also the good generality, and is suitable for different type coal-fired power plant and provides technical basis for guiding thermodynamic system design and operation and reasonable redevelopment.In addition, based on differential theory, in certain assumptions, analyzed influence of some small disturbing factors on thermal economy of unit under conditions of constant power output, and emphasized considered different sources where the steam leaks out, mathematical models have been obtained for quantitative analysis of the influence of steam leakage from HP and MP/LP cylinder on the unit thermal economy under conditions of constant power output. Simulated by the LabVIEW, Taking a300MW thermal power unit as an example, relevant calculations were carried out so as to analyze the influence of steam leakage respectively from HP and MP/LP cylinder on the unit thermal economy under typical working conditions. The results verify the validity of this method.