Thermodynamics System Simulation And Energy Efficiency Diagnosis Of Off-Design Condition

The online diagnosis of energy efficiency is an important content in the power plant energy fine management, but the present research methodologies and systems development are established on the basis of online data acquisition, some data may not be collected online and may be failure because of the data mutate or missing. Through the thermal system simulation on variable condition to realize the online diagnosis of energy efficiency are researched in the thesis.1> The research on general physical model and mathematics model of the calculation of energy efficiency. Synthesize the system structure and utilization modes of all kinds of auxiliary steam-water, a general physical model suitable for different thermal system is established through the introduction of several logical variables in the thesis. Based on the physical model, the general matrix form of the steam-water distribution equation is deduced by using thermal equilibrium equations of the heater, combined with steam turbine power equation and circulation heat equation composed of the mathematic model of the calculation of energy efficiency. The model is validated by calculating in600MW condensing unit and50MW double extraction unit, the result shows that the model is correct and versatile, and the characteristic of clear physical meaning and convenient to programming calculation.2、The research on the simulation of thermal system on variable condition. In order to realize the simulation of thermal system on variable condition, a model is established on the basis of the coupled relationship among different operation parameters by researching the features of steam turbine governing stage, pressure stage, condenser and heater on variable condition. The model is used to simulate the unit operational status on different condition, which avoid certain parameters of online acquisition not easily and can draw thermal characteristic curve. The model is validated by simulating the50MW double extraction unit, and simulates several typical operating conditions.3、The research on the energy efficiency diagnosis on variable condition. Deviation analysis is one of the effective ways to energy efficiency diagnosis, but it is difficult to determine the optimum operating condition and the optimal value of parameters. The main steam temperature, the main steam pressure, heater temperature difference and pressure loss to the influence of thermal efficiency are analyzed and the method of the determination of parameters’optimal values and energy consumption deviation analysis is established based on the thermal system simulation on variable condition. The paper uses50MW double extraction unit as example to carry on the analysis and diagnosis of energy efficiency.