Modeling Of Temperature Control System Of Water/Steam Receiver And Redundant Network Control System Design

With the adjustment of energy structure in our country, solar energy as a renewable and clean energy has been greatly developed. Solar thermal power generation is one of the main forms of developing and utilizing solar energy ,our country will construct a number of solar thermal power stations in "the 13th Five-Year" period, including various tower solar power stations.As a key equipment of photothermal conversion in solar thermal power system, stable and efficient operation of receiver has an important influence on the economic performance of the whole power station.Based on receiver as the study object, characteristics and control methods of receiver and the issues of real-time and reliability on the control system are studied.And this paper mainly finished the following contents:(1)By analysing the structure of water/steam receiver and according to the low of conservation of energy and mass, we discretized water/steam receiver tube along axial and radial direction and established sectional lumped parameter model. Based on the process parameters of receiver, the transfer function model of output temperature of receiver with various input is established.And the dynamic characteristics of receiver are obtained by the simulation analysis of the variation of output temperature with various inlet temperature of water/steam receiver, supply water flow and solar radiation.A analysis of model of water/steam receiver,it can be shown the defects of the existing control scheme of receiver. This paper puts forward a structure of control system between water flow and heliostat field which is similar to selective control, the structure can meet the control requirements under different working conditions greatly by mixing the characteristics of rapidity adjustment of supply water flow control and wide range adjustment of heliostat.At the same time, we propose strategy of multi target aiming and solve uneven heating problem of receiver by regulating heliostat.In view of the limitation of the PID control method to the receiver control, an improved generalized predictive algorithm is presented to control the temperature of receiver. And simulation results of Matalab show that the method has a good control effect.(2)In order to ensure the real-time and reliability of the control system, we propose three layer redundancy network structure of control system (CAN network layer, Ethernet, FDDI layer) and design the island controller as the key equipment of three layers redundant network.The data is packed layer by layer though three layers redundant network can ensure the real-time of control system.On this basis, the experimental platform of three layers redundant network is built and tested to confirm its real-time and reliability. Finally, it is applied to the actual project and meet the desired anticipation well.