| Based on the existing thermal well, combined with the basic theories of heat transfering, this article first studys the radiation heat transfer characteristic and radiation law of thermal well. Then it focuses on the radiation convection coupling with monte carlo method, optimizing the best structure. This article uses FLUENT to simulate the thermal well's velocity and temperature and energy's distribution, and verifies the feasibility of the method.The results show that with the distance L increasing, the thermal efficiency and the thermal well structure's average temperature reduces gradually, and the radiation power gradually declines. As the distance S increasing, the thermal efficiency and the radiation power increases, but the radiation well surface's temperature gradually reduces. The caculation result of the direct method and monte carlo method is consistent, and the radiation thermal efficiency is about 90%. Under diffuse reflection condition, when x of the parabolic radiation well is 146.8 mm, the thermal efficiency is the highest. The energy distribution is more uniform and reasonable and it is the optimal radiation well structure.For the heat transfer of radiation convection coupling, when x of the parabolic radiation well is 148.4 mm, the thermal efficiency is highest. The maximum thermal efficiency is 70.79%, the proportion of radiation is the largest. The energy density of the pot's bottom is high in the middle and low on the edge.The result of numerical simulation shows that the caculation and simulation is almost similar and the caculation's method is feasible.the velocity field and temperature field in the radiation well is symmetrical. The smoke's volume of both sides is significantly more than the front and back. The parabolic radiation well structure is superior to other structures.Through the above analysis, this article sums up a set of complete design method of hot well structure of the combustion unit. |
PDF Full Text Request