Thermal Power Unit Steam Turbine System Dynamic Simulation And The Economy Evaluation

The main power supply comes from coal-fired plants in China, safe and economic operation of coal-fired power plant is of great significant to stable supply of energy. Safe and economic operation partly depends on the reliability of the equipment, mainly depends on the operating level of power plant operator. As result, a higher demand for simulation is put forward.Lianyungang Hong Yang thermal power unit steam turbine system is the simulation object of this paper. According to the system arrangement, operation features, and equipment function, a full-scope simulation model of steam turbine system is developed with a simulation supporting platform IMAGE. Afterwards, combined with the design material, field data, this model is debugged in three steps: steady conditions debugging, dynamic debugging without control system and dynamic debugging with virtual DCS. Results suggest that the key parameters of steady-state conditions meets the accuracy requirements. Dynamic characteristic curves are accordance with those of real industrial processes and the theoretical analysis.This paper established the model of energy-loss analysis for heat supply units. An improved equivalent enthalpy drop method is developed to analyze the energy-loss of regenerative system parameters for extraction back pressure unit, and the influence of exhaust steam condition on turbine, deaerator and high pressure feed water heaters is analyzed. Unit parameters are divided into three parts:regenerative system parameters, turbine section parameters and boiler parameters. The energy-loss of regenerative system parameters are analyzed by the improved equivalent enthalpy drop method, the energy-loss of turbine section parameters is analyzed by a method combined the improved equivalent enthalpy drop method with the variable conditions calculation, energy-loss of boiler parameters is analyzed with the negative equation method. Results show that the improved equivalent enthalpy drop method is superior to the traditional equivalent enthalpy drop method when analyzing the energy-loss of this type of unit.This paper presents an economic evaluation method based on the energy-loss analysis. Exceed punishment marking and economic score are combined to evaluate the unit operation economy. Therefore, safety and economy of the unit can be quantitatively analyzed by economy evaluation score. This method evaluates the economic level of unit operation from three aspects:score of a single parameter at sampling point, score of a single parameter in an evaluation period, and score of all parameters in an evaluation period three levels. Through this method, safety and economy of the unit is evaluated and energy-loss distribution is exhibited.This paper combines the economic evaluation method with simulation to calculate the energy-loss and indicate it on the screen in real-time and guides the operators to adjust operation. At the end of the evaluation process, energy-loss distribution and a final score of the operator's operation in the evaluation period will be shown. Economic level of operations'operation is expected to be raised in the way.