Optimal Design And Performance Research Of Composite Phase Change Material Finned Tube Energy Storage Device

The traditional energy storage capacity of countries around the world is decreasing,and the dual urgent situation of energy shortage and environmental degradation is in front of human society.At this time,renewable energy is an inevitable research in energy research due to its advantages in sustainability and environmental protection.Direction,economic and social development must seek more effective use of renewable energy methods,but the application of these energy sources has certain volatility and intermittentness,which limits their prospects and application scope in industrial and living applications.Among the directions,phase change energy storage technology is undoubtedly a feasible and effective research technology direction.Phase change energy storage technology involves the discovery,modification and application of phase change materials.The phase change materials used have high energy storage,usually the temperature is relatively stable during the application process,the latent heat value is high,and the applicable temperature range is wide.It has been widely concerned in scientific research,but its shortcomings such as low thermal conductivity also limit the scope of application.In the improvement of these shortcomings of phase change materials,the related phase change material modification technology and the optimization of the application device of phase change materials are the main ones of research direction.In this paper,a composite phase change material finned tube energy storage device is designed and built.Through the study of the heat storage and release characteristics of the composite phase change material in the tube and the infrared thermal image of the front of the heat storage box,the effect of different materials,different wind speeds and wind temperatures on energy storage is explored.The effect of the heat storage and release process of the device is obtained,and the general heat storage and release law and influence degree are obtained.Then,the effect of different fin numbers on the heat storage and release of the device is studied and analyzed.The design experiment studies the different placement methods of the multi-fin unit Changes in the temperature of the air outlet.The research content and summary of this article are as follows:The design and experimental principle of the experimental system are introduced.Through the selection and preparation of phase change materials,comparative analysis found that the composite phase change material with expanded graphite content of 4%,compared with pure paraffin,has less effect on the phase change temperature and latent heat value after composite.The thermal conductivity is increased by about 8.68 times.By analyzing and studying the temperature change of the phase change material and the temperature of the air outlet during the heat storage and release process of different phase change materials,and studying the infrared thermal imaging of the front of the box,it is found that the phase change time of the composite phase change material is advanced and the phase change is greatly shortened.Change the duration,the influence of expanded graphite has a greater impact on the liquid process.The composite phase change material in the exothermic process is significantly optimized than pure paraffin at all stages.The composite phase change material can accelerate the temperature rise of the air medium and adjust the temperature field.Better practical application effect.Design and study the heat storage process changes of phase change materials under different inlet wind temperatures.The research shows that there is a certain "threshold" for wind temperatures above 70℃,which can achieve substantial phase change optimization and improve energy efficiency.Through the analysis of infrared images It is found that when the temperature is low,there will be more heat loss in the space above the box.By studying the heat storage performance of the heat storage device under different wind speeds,it is found that increasing the wind speed has a good effect on the sensible heat absorption process of the composite phase change material in the early stage.Analyzing different wind speeds,it is found that increasing the wind speed above 4 sm / can bring higher heat storage efficiency,but at the same time,high wind speeds will also bring more energy loss.In practice,ventilation should be ended after the latent heat ends.It is found through infrared images that there are abrupt changes in wind speed between 4 and 5 sm /.The experiment analyzed the influence of different wind speeds in the heat release process,and found that the optimal heat release wind speed is in the range of 4-5 sm /.During the heat release process,the composite phase change material with high thermal conductivity is less affected by the wind speed,while pure paraffin wax is less affected by the wind speed.The wind speed has a greater influence.The infrared image shows that the heat accumulation is more serious in the initial stage of the heat release under the low-speed heat release,and the heat accumulation is one of the reasons that limit the heat release efficiency of the device.The heat storage and release temperature changes of the composite phase change material under 9 kinds of working conditions are compared.The analysis shows that the influence of wind speed at 80℃ is very small,and the effect of temperature difference at high temperature is greater;in the 9 working conditions,inlet wind speed 4 sm / and inlet wind temperature 70℃ is optimal.The heat storage and release characteristics of the phase change energy storage device under different fin numbers were designed and tested.The study found that there is an optimal number of fins between 30-60 fins,which can meet the cost-effectiveness and heat storage and release efficiency at the same time.Set up and studied the different placement methods of four phase change material fin tube units,studied the air outlet temperature and infrared thermal imaging,and found an experimental group placed in four rows At the same time,research has shown that dead space will cause a lot of energy waste.In practical applications,we should optimize the existence of dead space as much as possible,and pay attention to sufficient heat exchange between air medium and heat storage device.