Semi-physical Simulation Platform Of Power Plant Automatic Dosing System

The safe,reliable and high-efficiency operation of boilers in thermal power plants can not be separated from the high-performance dosing systems of power plants.However,it exists some problems in the dosing systems for power plants,such as long development cycle and complicated parameter adjustment.In order to solve this problem,a semi-physical simulation platform based on Simulink was constructed in this paper,and the hardware-in-the-loop simulation technology was applied in the development process of the dosing system.The development cycle can be shortened and the development cost for the dosing system of the power plant can be saved.More favorable conditions can be created for R&D workThe dosing system of Bohai Power Station was taken as an example.The PID parameters of the system was pre-commissioned by using the semi-physical simulation technology to solve the problems of long time and high cost of field setting parameters.In this thesis,the following aspects are carried out:1.Analysis of the dosing system of a power plant and establishment of the model for the furnace waterThe work flow and chemical principle of the dosing system of the power plant were analyzed in details.The entire process of the boiler water cycle was explained,which shows that it is consistent with the performance of the first-order linear pure-delaying model.On this basis,the dosing model was abstracted.Combined with the actual situation on site and the experience of first-line engineers,a boiler water model was established in Simulink.2.Analysis and Research on Key Technologies of Hardware-in-the-Loop SimulationA scheme for establishing a hardware-in-the-loop simulation platform for the dosing system of power plants was proposed.The free port communication protocol was used to realize the data transmission between the upper computer Simulink and PLC to meet the real-time requirements of the hardware-in-the-loop simulation.The external devices were selected reasonably.The semi-physical simulation platform of dosing system of power plant was established.3.Semi-physical simulation experiment of dosing system of power plantSemi-physical simulation experiment on the dosing system was carried out on the semi-physical simulation platform.Firstly,the response of the post-dosing system was compared with the step response diagram of the first-order linear pure-hysteresis model to prove that the boiler water model can be used for the semi-physical simulation experiment.The appropriate PID parameters were adjusted through the experiment.The response of the dosing system under various operating conditions was simulated.