考虑路易斯数的逆流塔热力学模型及运行特性分析

摘要

Sets up a thermodynamic model based on mechanical draft counterflow cooling tower with the fully consideration of Lewis number and the change of characteristic number.Verifies accuracy and reliability of the model with a subway station in Guangzhou as test object,and analyses the influence of Lewis number and correction coefficient of characteristic number on cooling tower.The results show that the relative errors of outlet water temperature and inlet air enthalpy are below 2% and 3%,respectively. For large temperature difference,using Lewis relation can result in a large deviation between the simulated and the experimental results,especially for larger difference between the dry-bulb temperature of inlet air into tower and the temperature of inlet water.The relative errors of the outlet air temperature and the relative humidity can reach 16.7% and 10.7%,respectively.The more the actual characteristic number deviates from the standard condition value,the greater the impact on performance of cooling tower is.%以机械通风逆流塔为研究对象，在充分考虑路易斯数及冷却塔特性数改变的基础上，建立了热力学模型。以广州地铁某站点逆流塔为测试对象，验证了该模型的准确可靠性，分析了路易斯数和特性数修正系数对冷却塔的影响。结果表明，出水温度相对误差低于2％，进风比焓相对误差低于3％；进塔干球温度与进水温度相差较大时使用路易斯关系式会导致较大误差，出塔空气干球温度相对误差可达到16．7％，相对湿度可达到10．7％；冷却塔实际特性数越偏离标准工况值，对冷却塔性能影响越大。