Numerical Simulation And Optimization Study On The Container Of Mobilized Waster Heat Utilization System

The industrial sector generates large amounts of waste heat each year,which not only reduces the energy efficiency in production,but also burdens the energy demand of our country.At present,waste heat recovery presents a double energy loss situation.On the one hand,a large number of industrial waste heat resources are not fully utilized and were wasted,on the other hand,most of the northern cities and towns have not laid the central heating pipe network and rely on their own boiler to produce thermal energy.In order to improve these problems,this paper has carried out the following research work on the mobile waste heat utilization system:According to the phase change temperature,thermal conductivity,phase change latent heat,economy and safety of the heat storage materials,70 # phase change heat storage balls produced by ×× Company were selected as phase change heat storage materials.The melting point,freezing point and phase change latent heat of the phase change materials were obtained by differential scanning calorimetry(DSC),which provided the data reference for the following simulation.The shell-and-tube heat exchanger was selected as the core component of the mobile heat storage system,and the heat storage and heat release process was simulated by FLUENT software.The results show that when the phase change material is stored for 7 hours,the internal phase change material is almost completely regenerated.Only the "dead zone" is formed on the sides and bottom of the heat accumulator.In order to increase the storage or heat release rate,and eliminate the heat storage "bottleneck",by changing the heat pipe diameter size,arrangement and method of adding fins to strengthen heat transfer.The influences of the number of fins,height,thickness,width and straight fins and T-shaped fins on the heat storage performance were also discussed.The results show that the effect of natural convection can be restrained by the addition of fins,which can improve the heat transfer efficiency.With the increase of the fin height,width,thickness and the number of circumferential fins of the single heat transfer tube,the heat release time of the heat storage system is reduced to different extents.On the basis of the design and numerical simulation of the mobile thermal storage system,the cost and benefit analysis of the mobile heat storage system for the waste heat recovery of Tianjin × × thermal power plant were carried out.And from three aspects of feasibility,economy and social benefits of the project,the importance of mobile waste heat utilization technology in industrial waste heat recovery is analyzed.The results show that mobile energy saving heating is the best way to reduce the cost,save energy and environmental protection,and ban the smallcoal-fired boilers.