Application Research Of Phase Change Energy Storage In Cooling Water Waste Heat Recovery System Of Marine Main Engine

Phase change energy storage technology is the use of materials' latent heat to charge and discharge heat,the use of phase change energy storage technology in the recovery of waste heat in cooling water recycling ship host,can effectively improve the energy efficiency of ships,also can solve the waste heat utilization in the process of time and space does not match.In this paper,we design a casing with a ring fin heat exchanger structure,with paraffin as phase change materials,used to recycle host cooling water waste heat of the ship.First of all,according to the main engine cooling water heat temperature of 80?,considering the selection of paraffin phase change temperature at 80?,and the thermal parameters of DSC,Hot Disk thermal analysis instrument for measuring the paraffin.And then through the analysis of the theory of phase change heat transfer,with appropriate assumptions,built with finned tube physical model and mathematical model of concentric tube heat exchanger,and heat test bench is established.Then use FLUENT simulation analysis on the process of phase transformation,the natural convection on paraffin melting process,the influence of storage at the same time analyzed the inner tube with fins and a vertical state of phase change heat exchanger of paraffin in melting process,and compares the different fin structure and the performance of different conditions on the paraffin melting process.The final design phase with 5 tube fin heat exchanger unit,The phase change heat transfer system is formed with the low temperature constant temperature tank,the flowmeter,the thermocouple and the Agilent temperature collector,and the heat storage process of the phase change heat exchanger is analyzed.The results show that the phase change heat exchanger can effectively recycle the quantity of heat of hot fluid.Through the simulation result,the natural convection phenomenon is a great influence on paraffin melting process,but less effect on the solidification process,and even can be neglected.Because of the heat exchanger finned tube installation,paraffin melting rate increased,the heat transfer efficiency of phase change heat exchanger has been effectively improve,inner pipe installation time needed for five wings were paraffin melting than inner tube no wings were cut by half,and different quantity and structure of the fin had a great influence on phase change process.Experimental results and the results of numerical analysis and comparison,it is inevitably exist in the experimental process heat loss,so the result of the experiment and numerical analysis results have a certain error,but the experimental measurement results and simulation results are basically the same trend.