Numerical Simulation And Optimum Research On Jacket-type Heat Pipe Heat Exchanger

Heat exchanger was the key equipment in the industry. The heat pipes heat exchanger as a new type heat exchanger, with the higher heat transfer efficiency, the lower pressure, vibration prevention and the advantages of compact structure, developed rapidly.This new jacket heat pipe and heat exchanger have been in-depth studied in my paper, using computational fluid dynamics software FLUENT 6.3 as the platform with experimental test data for the boundary conditions of numerical computation.Theκ-εprocess model for exchanger numerical computation and structure optimization was selected.The main research results and conclusions were as follows:1) By using the heat pipe experiments, the heat pipe working fluid and tube wall temperature distribution were acquired, the heat pipe total heat transfer and heat pipe working fluid of steam heat transfer discipline were discovered,and the experimental correlation of steam evaporation rate and heat transfer coefficient were obtained.2) The temperature distribution of 5 different filling rates and 3 different heating source were obtained.The results showed that:the heat pipe at the top of the latest local temperature was maximum and the steam back phenomenon occured at the heat pipe top. With the same method, the velocity distribution was obtained. We found that where the lowest velocity rate was near the top of the cooling water pipe, where the cooling rate was the maximum. The relative error of numerical simulation and experimental data was less than 5%.3) Heat pipe wall temperature simulation results showed that the wall temperature from the bottom to the top increased. For the heat pipe of the filling rate 40%, the temperature addition became smaller and smaller; For the heat pipe of the filled rate 50%, when the horizontal coordinates was in the range 7.5mm～22.5mm, the temperature was close to linear increase. After that, the addition became smaller and smaller4) The SIMPLE algorithm was used for heat pipe heat exchanger simulation. The variation of temperature,velocity and local heat transfer coefficient along the shell were studied with different flow rates. The results showed that the temperature contour lines around the tube was intensive. The temperature gradient was large, however, The temperature distributed evenly and temperature gradient was smaller in the middle of each tube bundle and the region between the wall and the shell. With the flow velocity increased largely, the turbulence intensity increased. So the heat transfer coefficient also increased. But the heat pipe heat exchanger temperature disparity was reduced; When the fluid flows through the tube, there was a wedge vortex area where the speed was maximum. The largest turbulence intensity was in the central region. Also, the heat transfer intensity of the central region was significantly higher than the edge.5) The influence of structure parameters for heat pipe heat exchanger heat transfer and pressure drop were analyzed. Optimization Results:horizontal pipe pitch was from 114mm to 120mm; vertical tube pitch was from 120 to 125mm; fin height should be higher than 26.5mm; 6mm was the ideal fin spacing pitch.