CO2不同螺纹管管外强化换热的实验研究

通过对CO2的物理特性及水平光管与不同螺纹管管外沸腾换热进行实验研究,得出了换热系数随蒸发压力和热流密度的变化关系。拟合得出CO2在蒸发压力的范围为2.6~3.6MPa、热流密度为10~50 kW.m-2的换热关联式h=A.qn。与Cooper预测值的偏差在±15%之内,与Ribatski关联式预测值的偏差在±7%之内,与Ye实验关联式预测值的偏差在±9%之内。在CO2在光管管外沸腾换热的基础上进一步研究其在螺纹管管外沸腾对换热的强化效果,为CO2强化换热进一步发展提供依据,具有一定工程实践意义。

Experimental Research on Heat Transfer Enhancement Out of Different Screwed Tubes

CO2 physical characteristics and boiling heat transfer out of smooth and screwed tubes in this paper. The relationship between heat transfer coefficient, evaporating pressure and the heat flux is obtained through experimental analysis of CO2 boiling heat transfer outside a horizontal smooth tube. The fitting correlation according experiment data when CO2 evaporating pressure range is 2.6~3.6 MPa and heat flux range is 10~50 kW/m2 is: h=A*qn. The calculated value deviation of new correlation with predicted value of Cooper correlation is within ±15%, with Ribatski correlation is within ±7% and with Ye correlation is within ±9%. Based on the analysis of CO2 boiling heat transfer outside a horizontal smooth tube, a further study on CO2 boiling heat transfer outside screwed tubes is taken in this paper. The results provides a basis for promote development of CO2 heat transfer enhancement, and also provide a support for promoting engineering.