Research On The Key Technologies Of The Closed Cooling Water System

With the development of the industry, cooling water system, mainly composed of closed circulating pipelines, water pump and cooling towers, is widely used in metallurgy, power sector, air-condition industry, machining and other fields. The key technologies of cooling water system are the installation of valves and orifice in the circulating pipeline, the characteristics of the pump and the heat transfer capability of the cooling towers, affect directly the work performance of the whole cooling water system.The characteristics of three key parts of the cooling water system is simulated by Fluent in this thesis, the main work and conclusions are as follows,The flow field of the pipeline with orifice is simulated. Three factors, the water inlet velocity, the aperture ratio and the thickness-diameter ratio which influenced the length of the disturbance flow field behind the orifice are studied. The result shows that the parameters of the orifice has great influence on the length of the disturbance flow field behind the orifice, the water can enter the recovery area quickly by reasonable optimization of the orifice parameters.The taper of the eccentric reducer is defined, the influence of the eccentric reducer in front of the pump to the pipe flow field and the cavitation phenomenon on the pump entrance is studied. The result shows that the phenomenon of cavitation can be effectively reduced by choosing reasonable eccentric reducer, the effect of cavitation phenomenon to the pump body can be reduced by increasing the distance between the vertical pipe section in front of the pump and the pump body.The flow field inside the closed cooling tower is simulated, by changing the air quantity of the cooling tower, the flow rate of the spray water and the flow of cooling water, the influence of the temperature difference between the inlet and outlet of cooling tower is studied. The results show that the heat transfer capability of the cooling towers is improved by reasonable choice of the ventilation rate and the amount of spray water.