成人黄色av电影_日本一区免费视频_94-欧美-setu_日韩va欧美va亚洲va久久_中文字幕av一区二区三区 _国产精品福利一区二区_777色狠狠一区二区三区_日韩av网站在线观看_国产精品蜜臀av_欧美视频完全免费看_1区2区3区国产精品_色综合色狠狠天天综合色_国产精品一区专区_青青草原综合久久大伊人精品优势 _91福利国产成人精品照片_欧美美女一区二区在线观看

1, plate heat exchanger flow patterns are countercurrent, downstream and mixed flow pattern.
Under the same operating conditions, the logarithmic mean temperature difference is the largest in the countercurrent flow, and the flow rate is the smallest, and the mixed flow pattern is between the two.
The method of increasing the logarithmic mean temperature difference of the heat exchanger is to use the mixed flow pattern of countercurrent or countercurrent as far as possible, to increase the temperature of the hot side fluid as much as possible and to reduce the temperature of the cold side fluid.
2, for a single process layout of the plate heat exchanger, for easy maintenance, fluid inlet and outlet pipe should be arranged as far as possible in the heat exchanger fixed end plate side.
The greater the temperature difference of the medium, the stronger the natural convection of the fluid, the more obvious the effect of the retention zone.
So the media inlet and outlet position should be carried out by the hot fluid into the cold fluid into the out of the layout, in order to reduce the impact of the retention zone, improve heat transfer efficiency.