Simulation And Dynamic Analysis On Thermal Power Generation System

With the rapid development of power generation unit, the large-capacity and high-parameters units will be the direction for the power generation plant, and the system will also be more complicated. This is a challenge to the security and economy of the power plant. There is an urgent demand for the operators to develop higher operation skills and adaptability to the changes. However, the training chance on actual power plant is very few, so the simulation system of the power plant has developed rapidly. Besides, from the simulation system, characteristics and some important faults of the plant can be investigated, which could be incorporated into failure diagnosis theory to set out effective anti-fault methods.Referring to the experience of the power station simulation in foreign and domestic field, a simulation system was developed. The main points are described as follows:1. The modular modeling method was adopted to develop the module library for the main components of power plant based on EASY5 simulation platform. The volume model was introduced, with the state variables, to solve the pressure-flow coupling problem, thus the iterative was eliminated and the calculating efficiency was increased. According to No. 1 plant, a simulation model for this thermodynamic system was developed.2. The model validation was performed with the rating experimental datas. Compared with the experimental data, the simulation results are reasonable. In addition, the data in different operating conditions revealed that the simulation model was effective.3. Based on the actual operation process, some operating conditions burning with low heating value fuel gas and coal were simulated. When burning with low heating value fuel gas and coal in the power plant, the exhaust gas temperature was higher and the boiler efficiency was decreased. Considering that the heat transfer was not enough, the heat loss was increased. The sensitivity analysis of the main heat transfer components has been implemented. And the surface of the air heater was the most sensitive factor to affect the system performance. Some suggestions have been proposed, it will be helpful to improve the system performance and system design.4. The performances of the power plant under the conditions of furnace slagging and ash deposition of heating surfaces in the boiler were simulated. Through fault simulation, the changes of the performance parameters can be analysed and compared. The results can be used in fault diagnosis system as the diagnosis criterion in the expert system for fault diagnosis.5. Based on the system model, the dynamic response was simulated. The dynamic responses of the system parameters were reasonable. It can be seen that the inertia time constant for the system was about 700s, which can be used as reference to improve control performance.