Research On Key Technologies Of Energy Saving Optimization For Circulating Cooling Water System In Steel Plant

In industrial production,a large amount of waste heat is generated,which requires cooling and dissipation to ensure continuous production.Therefore,the circulating cooling water system is widely used in industrial enterprises and runs hour after hour.This makes the system energy consumption account for a considerable proportion of the total producing energy consumption,while the system's energy efficiency is always reduced due to unreasonable design,unsuitable equipment selection,and lack of timely evaluation and maintenance of its state.With the support of the Shanghai Science and Technology Commission Research Program(13dz1201700),Baosteel Energy aims at energy-saving operation of industrial circulating water systems,and conducts common technology research on the design,operation control,performance optimization and economic operation evaluation of the entire system.The main research contents include:(1)Summarize the status quo of energy performance of industrial circulating water systems,and investigate the research progress and trends in energy saving of circulating water systems at home and abroad,and point out the direction for the present research.(2)Establish a system operation simulation platform.The hydraulic and thermodynamic models for the basic components of the circulating water system,including cooling towers,heat exchangers,pumps,valves,nozzles and piping,are established,and on the basis of classic physical laws and topological theory,the calculation model of energy consumption simulation is established,and then the solving process and algorithm are given.Examples show the method has a certain accuracy,which lays a theoretical foundation for the optimization and design of the following text.(3)Design and build a set of circulating water system combined energy-saving experiment device based on industrial circulating water system design code.The device experiment compares the energy efficiency of different operating conditions and different technologies,which lays a foundation for system structure and operation optimization..(4)Propose two heat exchange piping optimization methods based on series-parallel and intermediate temperature.The simulation analysis shows that the series-parallel mode is beneficial to reduce the system energy consumption in that it can help reduce the flow-rate to nearly one-third.(5)The design optimization model and operation optimization model of circulating water system are established.The hierarchical nested algorithm and genetic algorithm are used to solve this kind of mixed integer non-linear programming problem.Delphi and MATLAB are used to redevelop EPANET water analysis software.With the support of MySQL database,the software optimization platform of the system which can support the decision of energy-saving is then established.(6)Analyze the performance of the cooling tower.The performance of the cooling tower is critical to the cooling efficiency of the system.To this end,by analyzing the three-dimensional flow in the cooling tower,the influence of various design parameters,such as the air-water speed ratio,the inlet angle,and the spraying density,and etc.on its performance is calculated,and the running noise is simulated too.The analysis results are basically consistent with the actual situation.The analysis may help the performance optimization of the cooling tower.(7)Establish an energy efficiency economic operation evaluation system for circulating water systems.Based on the experimental analysis of the device,the influencing factors and corresponding evaluation indexes of the energy efficiency of each component of the system are determined,and the energy efficiency and economic operation evaluation system of the system is established based on the fuzzy comprehensive evaluation method.The example shows that the evaluation system can provide improved ideas and suggestions for the circulating water system.The design and optimization of circulating water system,performance analysis,system experiment and energy efficiency evaluation and analysis are comprehensively discussed.The key technology research of energy-saving economic operation of industrial circulating water system is focused on the combination of theory and practice.The research of the subject is directly oriented to the actual industrial circulating water system,so the research methods and conclusions may have important guiding significance for the energy saving and economic operation of the system.