摘要
利用EVAP-COND软件计算分析了风速均匀分布以及风速呈下三角、上三角、中三角分布对双排管两流路蒸发器性能的影响,结果表明:风速分布越均匀,蒸发器的换热量越大,风速呈中三角、上三角和下三角分布时蒸发器的换热量分别比均匀分布时小8.5%、34.3%和35.3%;风速非均匀分布使两支路的风量不同,导致总传热系数减小,从而使得蒸发器的换热量减小;两支路的风量差别越大,制冷剂出口状态差别越大,制冷剂流量就越小,蒸发器的总换热量也就越小;风量大的支路易产生逆向传热现象,这更加恶化了蒸发器的传热性能,而空气温度低于制冷剂温度是逆向传热产生的原因;风速非均匀分布时,支路数对蒸发器的性能影响非常显著,存在着使蒸发器换热量最大化的最佳支路数.
The effects of the airflows with the same flow rate and different air front velocity distributions on the performance of a two-row finned tube evaporator with two circuits were numerically studied by the software EVAP-COND 2.1.The air velocity distribution was in four shapes,i.e.,rectangle,two triangles with respective upper and lower right angles,and isosceles triangle.The results show that the evaporator capacity increases with the increase in the uniformity of the air velocity distribution.The capacity for the isosceles triangle,two triangles with upper and lower right angles is 8.5%,34.3% and 35.3% less than that for the rectangle shape,respectively.The non-uniform distribution of the air velocity causes different airflow rates of the two circuits,leading to the reduction of the overall heat transfer coefficient and then the decrease in the evaporator capacity.The different airflow rates of the two circuits result in different refrigerant outlet states.The refrigerant flow rate and the evaporator capacity decrease with the increase in the difference in the refrigerant outlet states between the two circuits.Moreover,the reverse heat transfer occurs easily for the circuit with greater airflow rate because the air temperature is lower than the refrigerant temperature.In addition,when the air velocity distribution is non-uniform,the effect of the circuit number on the evaporator capacity is significant,and there is an optimum circuit number.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2010年第5期50-55,共6页
Journal of Xi'an Jiaotong University
基金
教育部长江学者和创新团队发展计划资助项目(IRT0746)
关键词
风速分布
蒸发器
换热量
风量
制冷剂出口状态
air velocity distribution
evaporator
capacity
airflow rate
refrigerant outlet state
作者简介
作者简介：李权旭（1986-）．男，硕士生；
黄东（联系人），男，副教授．
