在线视频这里只有精品|久久九九青青国产精品|欧洲精欧洲精品高清一区|久久女同精品国产一区二区|亚洲精品无码久久久影院男|亚洲va精品中文字幕动漫|AV无码人妻精品丰满熟妇区|欧美国产日本精品一区二区三区

The heat exchanger is a device that transfers part of the heat of the hot fluid to the cold fluid, also known as the heat exchanger. Heat exchanger occupies an important position in chemical, petroleum, power, food and many other industrial productions. In chemical production, heat exchangers can be used as heaters, coolers, condensers, evaporators and reboilers, etc., and are widely used .