逆流湿化器的效能分析

Energy effectiveness analysis of countercurrent humidifier

采用75组逆流湿化器实验数据,对基于改进效能定义式的直接接触换热器ε-NTU方程进行了验证,并分析了压力、水气比、进口水温、进口空气湿球温度等操作参数对热容量流比和效能的影响。结果表明,改进ε-NTU方程的最大计算相对误差为27.7%,可用于工程计算;热容量流比随操作参数的变化单调增减,而效能曲线在热容量流比等于1时存在最小值拐点;固定操作压力下,进口空气湿球温度、水气比、进口水温的变化对逆流湿化器效能的影响依次减小。

In this paper,theε-NTU function of direct contact devices based on modified energy effectiveness definition was verified by 75groups of countercurrent humidifier experimental data.The affection of pressure,water/air mass flow ratio,inlet water temperature and inlet air wet bulb temperature on heat capacity rate ratio and energy effectiveness were analyzed.The results show maximum relativeerror of modifiedε-NTU function is 27.7%,which can be used in engineering calculation.Heat capacity rate ratio change monotonically increase or decrease with operation parameters,while energy effectiveness curves has minimum inflection point at heat capacity flow being equal to 1.At fixed operating pressure, the affection of inlet air wet bulb temperature,water/air mass flow ratio and inlet water temperature on energy effectiveness of countercurrent humidifier decreases in turn.