Study On Stable Operation Optimization Of Water Supply System Composed Of Strong Coupled Multi-Pump Source

As one of the important subsystems,the floating nuclear power system has a complex system.In actual operation,there are many working conditions and large load changes.Its operation performance directly determines the safety and stability of the whole platform.The development of reasonable water supply control strategy can improve the operation stability of condensate and water supply system,which is of great significance to the safe operation of offshore floating nuclear power platform.This paper takes the condensate and the water supply system of off shore floating nuclear power platform as the research object,and focuses on improving the safety of offshore floating nuclear power,and adopts the technical means of the combination of numerical simulation and experiment.Be aimed at the multi-pump parallel system is easy to produce the failure of double pump parallel operation under low flow conditions,Build 1:1 electric variable frequency water supply system;complete the overall development of the condensate and water supply system model;adjust the hydraulic characteristics of the feed pump,the speed of the feed pump,and open or close characteristics of shuttle cut-off check valve to recurrent the failure of low flow double pump operation in the experiment.Design and development control method for stable operation of strong coupled multi-pump water supply system in the case of the water supply regulating valve failure and low flow double-pump parallel operation failed,research shows:The experimental results find that the multi-pump parallel system is easy to produce the failure of double pump parallel operation under low flow conditions.The main factors include the difference in the hydraulic characteristics of the feed pump,the speed control characteristics,and the opening and closing characteristics of the shuttle cut-off check valve.(1)The simulation results show that when the characteristic curve deviates by more than 0.5% in the type of electric variable frequency feed pump,the double pump parallel operation will fails.Abnormal closed rick occurs when the minimum differential pressure of shuttle cut-off check valve deviation reaches 30 k Pa.(2)In the process of rapid load change under the fault of the water regulating valve the control strategy of increasing speed of electric feed pump is good.In the process of load reduction,the system can restore the smooth operation in about 75 seconds.In the process of load up,the system can restore the smooth operation in about 25-50 seconds.(3)In the case of double pump parallel operation running failed,control strategy of increase the electric feed pump,control strategy of switch over the feed pump,operation effectively,can effectively restore the shuttle cut-off check valve to the normal open state,the system can operate with two pump parallel,in general,control strategy of increase the electric feed pump has the best effect and can use versatility.Conclusion: This thesis addresses two kinds of safety problem in the operation of multi–pump parallel water supply system,research objective are clear,has a correct method and accurate model,several proposed control strategies optimization schemes eliminate individual differences between devices,it effectively improves the safety of the condensate water supply system of the offshore floating nuclear power plant.