Experimental And Numerical Simulation Of Cooling Characteristics Of Nickel Foam Plate

The foam nickel is mainly used in the electrode materials of MH/Ni and Cd/Ni batteries.This kind of batteries have the characteristics of excellent electrical performance,reasonable cost performance and environmental friendliness and safety.Foam nickel is often prepared by foam plastic electroplating.The preparation method is suitable for large-scale continuous production,and the product quality uniformity and the quality reliability are higher.But in the actual production process,it happens sometimes for nickel foam to crack.Because of the location and time of the occurrence of microscopic crack is random,it is difficult to determine the exact cause.In order to understand the cause of dark crack in foam nickel plate,in this paper,a series of researches on thermal stress during the cooling process of foam nickel plate are carried out.The main research work is as follows:1.The experimental platform was set up on the foam nickel production line.The production process of foam nickel was studied by experiment.The relevant parameters in actual operation are obtained,including the thermostats of the oxidation period,the temperature distribution of the cooling section,and so on.It provides reference for subsequent numerical simulation.2.The numerical model of flow and heat transfer in cooling section is established.The reliability of numerical simulation is verified by experiments.This model is used to simulate the heat transfer process of nickel foam in cooling section,then the flow field and temperature field distribution of the cooling section are obtained.By analyzing the temperature field of the nickel foam,we got the location and number of the maximum temperature gradient of the foam nickel plate.3.Based on the numerical calculation model,the paper analyzes the influence of gas inlet velocity,temperature,nickel foam plate movement speed and gas inlet area,location on foam nickel plate's maximum temperature gradient.Research results show that,the influence of the velocity of the nickel foam and the inlet location on the maximum temperature gradient of the nickel foam plate is significant.Therefore,in the design of cooling section,if the inlet position of gas is arranged on the side of cooling section,it can produce better heat transfer effect.4.Based on the distribution characteristics of the heat transfer process,the thermal stress of the nickel foam plate was calculated.First,the integral thermal stress distribution of the nickel foam plate was analyzed.Second,a three-dimensional model of foam nickel cell structure was established,and use the temperature field at the maximum temperature gradient of the foam nickel plate as the load,and the thermal stress of the cellular structure was researched.Finally,three kinds of cellular elements with defect structure were set up,and the influence of defect structure on the thermal stress of nickel foam was studied.