Research Of Operating Strategies At Water Intake Pumping Stations Under The Time-of-Use Electricity Tariff

The water intake pumping station is the key link of the water treatment system and the main energy-consuming.The energy cost of the pumping station accounts for a high proportion of the operation cost of the pumping station.Making a reasonable operation plan with the consideration of time-of-use electricity tariff can effectively reduce the energy cost of the pumping station.The maintenance cost is an important part of the operation cost of the pumping station.When making a pumping station operation plan,frequent starts and stops of the pumps and uneven cumulative operation durations among the pumps are also problems that need to be considered.Comprehensively considering the energy cost and maintenance cost of the pumping station,this thesis conducts research on the operation optimization of the water intake pumping stations and gives a variety of operation strategies.The main research contents are as follows:(1)This thesis summarizes domestic and foreign research status of pumping station operation problems,and the related algorithms based on the retrieval of related journals,monographs,conference papers and other types of references.(2)A start-stop optimization problem of a single type of pump with the purpose of minimizing the maximum number of start-stop times is studied.Based on the time-of-use electricity tariff,considering the large fluctuations of the natural water level and frequent starts and stops of the pumps and large differences of the start-stop times during the operation period of water intake pumping station,an operation optimization problem of water intake pumping station with homogeneous pumps is proposed.Taking the running state of the pump and the maximum number of starts and stops as decision variables,and minimizing the energy cost and the maintenance cost of the pumping station as the optimization objective,a nonlinear integer programming model is established.According to the characteristics of the problem and model,the optimization software CPLEX can be used to solve the problem.The validity of the proposed method is verified based on a large number of instances.The computational ability of CPLEX and the weight effect of start-stop cost in the model is analyzed.Finally,the results of the model with maximum start-stop times of pumps and the model with total start-stop times of pumps are compared,and operating strategy recommendations are given.(3)The start-stop optimization problem of a single type of pumps considering accumulative operation time is studied.The accumulative operation time of water pump is an important factor in making maintenance plan.In order to reduce the differences between the cumulative operation time of the water pumps,two non-linear integer programming models are established.One model is with the consideration of accumulative operating time,and the other model is with the consideration of accumulative operating time and maximum start-stop times of pumps.Based on a large number of instances,CPLEX software is used to solve the two models.The experimental results show that both of the two models can reduce the accumulative operation time differences of the pumps,and the model with the consideration of accumulative operating time and maximum start-stop times of pumps can also effectively reduce the number of start-stop times of pumps.Finally,the operation strategy is suggested for the intake pumping station with the same type of water pump.(4)The start-stop optimization problem of multi-types of pumps considering startstop times is studied.Taking into account the differences in the start-stop costs of different types of water pumps,two non-linear integer programming models are established with the optimization goal of minimizing the energy cost and the maintenance cost of the pumping station,which are model with the total start-stop times of the multi-type pumps and model with the maximum start-stop times of the multi-type pumps.Based on a large number of instances,CPLEX software is used to solve the two models.The experimental results show that both models can effectively reduce the number of start-stop times of the specified type of pump,and the model with the maximum start-stop times of the multitype pumps can also reduce the difference in the number of start-stop times between pumps.Finally,recommendations for operating strategies are given for water intake pumping stations equipped with multiple types of pumps.