加热方式对气泡泵提升性能影响的研究

Research on the Effect of Heating Method about the Lifting Performance of Bubble Pump

气泡泵是无泵制冷循环的核心部件,不同加热方式对于气泡泵提升性能有一定影响,提升性能可以用泵送比表示。利用两相流理论建立三维气泡泵两流体模型,通过文献数据验证了模型的正确性。以1atm下饱和水为工质,采用CFX模拟研究加热方式对于起泡泵提升性能的影响。结果表明不同加热段长度下,泵送比随加热量的增加先增大后减少,表示在一定加热功率下,气泡泵提升性能最佳。相同加热功率下,加热段越短,管内流态转变所需高度越小,气泡泵内可较快形成最佳流态。通过模拟不同加热功率、不同加热段长度下的气泡泵,发现在空泡份额α<0.8时,泵送比Spr与加热段长度占整管长度比例β为线性负相关。泵送比的预测对于气泡泵实际运行有一定的参考价值。

The bubble pump is the core component of the pumpless refrigeration cycle. Different heating methods have a certain influence on the improvement performance of the bubble pump. The improvement performance can be expressed by the pumping ratio. The three-dimensional bubble pump two-fluid model is established by using the two-phase flow theory, and the correctness of the model in this paper is verified by the literature data. Using saturated water at 1 atm as the working fluid, CFX simulation was used to study the effect of heating method on the elevating performance of the foaming pump. The results show that the pumping ratio increases at first and then decreases with the increase of the heating amount under different heating section lengths, indicating that the air bubble pump has the best lifting performance under a certain heating power. Under the same heating power, the shorter the heating section, the smaller the height required for the transition of the flow state in the tube, and the faster the formation of the optimal flow state in the bubble pump. By simulating the bubble pump with different heating power and different heating section lengths, it is found that when the cavitation fraction α<0.8, the pumping ratio Spr is linearly negatively correlated with the heating section length to the whole tube length ratio β. The prediction of the pumping ratio has a certain reference value for the actual operation of the bubble pump.