Experiment And Heat Transfer Analysis Of Energy Storage Air Flat Plate Collector

Solar energy resources as a prospect renewable energy resource are extremely rich in our country.However,wide applications of solar energy have been restricted by its shortcomings including intermittent availability,lack of stability,and collection difficultly.Solar energy storage technique is an effective way to solving the inconsistency issues between supply and demand.Latent heat storage technique has advantageous of its higher storing density,controllable operating temperature and high reliability.However,the low thermal conductivity of the phase-change materials(PCM)employed in latent heat storage system(LHSS)becomes a crucial factor to limit the practical applications of latent heat-storage techniques.Therefore,solar thermal efficiency of the LHSS can be effectively improved by choosing an appropriate enhanced heat transfer technology,and it is of great significance to solve the winter heating problem in northern China.In this paper,a fin-enhanced energy storage type air plate heat collector is developed.The design changes the structure of the heat-absorbing plate and adds long straight star fins to improve the cross-sectional area of the air flow channel and enhance the collection and release of solar radiation energy.Air as a heat carrier fluid(HTF)can effectively avoid problems such as water leakage and severe corrosion in the process of energy transmission.The device has a simple structure,stable operation,safe and efficient,and is used in building heating,drying and dehumidification and balanced indoor thermal ventilation.The field has strong use value,combined with testing to determine the effect of the solar flat plate collector(heat collector)directly integrated with the cylindrical phase change energy storage unit with long straight star fins on the light-to-heat conversion gain,By recording solar radiation,inlet and outlet temperature and wind volume,analyzing the temperature distribution characteristics of phase change material(PCM)time and space,testing the installation inclination,solar radiation projection amount,ambient temperature and convective air flow to the flat panel heat collector The effect of collection/heat dissipation performance.The results show that:in the western Inner Mongolia region from August to September,the heat collection device has the best heat collection effect when the installation angle is 45°,the heat storage is positively correlated with the solar radiation,the convection air volume is adjusted appropriately,and the heat dissipation performance of the device is also significantly improved,The air volume is controlled at 150m~3/h,the total heat collection is 19300kJ,the heat collection efficiency can be up to 71.4%,the average heat dissipation power of the device is 283W,the total heat storage of phase change energy storage is 10146kJ,and the heat dissipation efficiency of the heat collecting unit can reach 91%.The addition of long straight fins not only strengthens the conductive performance of paraffin,but also reduces the temperature difference of paraffin inside the heat collection unit,and shortens the energy storage time.The device can be widely used in building indoor heat ventilation,drying device and air pretreatment of air source heat pump evaporation section.