| The method of high pressure water descaling has become the main effective technique for the scaly treatment of hot rolling production line at domestic and abroad up till the present moment.High pressure water descaling technology is basically mature both in descaling principle and descaling process compared with chemical descaling,flame cleaning descaling and mechanical descaling.With the strengthening of the energy saving and emission reduction concept in various industries,on the basis of meeting the effect of descaling,energy saving and consumption reduction have become the survival base of the industry.Therefore,how to reduce the energy consumption under the requirement of descaling becomes one of the most important goals for the future technological innovation of the industry.In recent years,the desalination system of the new hot-rolling production line has been transformed by frequency conversion water pumps,but the energy saving is limited to the descaling intermittent.In practice,there is little or no reduction operation of the descaling pump according to the descaling rhythm,type and width and the flow demand of descaling points in the rolling process.The speed and stability of the control for the pump moter are realized by designing the motor controller under the condition of the normal operation of the descaling point,and by optimize the hitting pressure of the external flow field of the nozzle,we can reduce the minimum pressure needed for descaling,so as to reduce the energy consumption of the pump.The main contents of this paper based on this deficiency are as follows:(1)Reading related literature,understand the development of high pressure water descaling technology and pump frequency conversion technology at domestic and abroad.(2)The determination of the system's energy transfer by interpreting the principle diagram of the high-pressure water descaling system carefully,analyzing the components of the high-pressure water descaling system and understanding the working principle of each component.(3)The dynamic process and interaction between power frequency pump,variable frequency pump and accumulator under the combined water supply for descaling are studied by using software of AMESim.The above analysis can provide the reference for the energy saving optimization of the pump below.(4)The flow of descaling operation point is optimized based on NLPQL algorithm combined with the characteristics of power frequency pump,variable frequency pump and accumulator combined water supply and the flow-power and flowefficiency curve of frequency conversion pump to study and analyze the energy saving of variable frequency conversion of water pump under different descaling point conditions.Then the influence of the water supply mode of high pressure water descaling on the energy saving for the pump is studied.(5)Then,the variable frequency controller of high pressure water descaling pump is designed to realize the energy saving of the system.The establishment of mathematical model for the time-varying,nonlinearity,pure lagging and unstable characteristics of high pressure water descaling and frequency conversion constant pressure water supply system.Then,four different controllers are designed to simulate the high pressure water descaling system,and the speed and stability of the system for high pressure water descaling frequency conversion are studied and analyzed.(6)Finally,the structure and installation of the nozzle of the high pressure water descaling actuator are improved to achieve the energy saving of the descaling system.Through the analysis of the external flow field of structure parameters of nozzle and the installation distance of nozzle to determine the optimal design parameters of nozzle and jet target distance.The purpose of the study is to reduce the inlet pressure at the descaling point nozzle while ensuring the descaling pressure,thereby indirectly increasing the pump speed range of variable frequency,reducing pump energy consumption. |
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