The air cooler is an auxiliary device for the "air-cool […]
The air cooler is an auxiliary device for the "air-cooled" generator. The air medium is used to forcibly circulate the generator and then cool the air with water. Air coolers are only used in "air-cooled" units.
The high quality air cooler is mainly composed of a tube bundle, a fan and a frame. The tube bundle includes a heat transfer tube, a tube box, a side beam, a beam, and the like. It can be arranged in three basic forms: horizontal, vertical and inclined (herringbone). Among them, the horizontal arrangement heat transfer area is large, the air distribution is uniform, and the heat transfer effect is good; when the inclined roof is arranged, Air Coolers the fan is installed in the central space of the herringbone, and the floor space is small and the structure is compact. In order to counteract the effect of the lower heat transfer coefficient on the air side, a tube with fins on the outer wall of the light pipe is usually used. The finned tube acts as a heat transfer tube to expand the heat transfer area. The finned tubes are arranged in layers, and the two ends are connected to the tube box by welding or expansion. The tube is generally 3 to 8 rows. The tube bundle series is up to 12 meters in size.
The outer diameter of the light pipe is usually 25 mm and 38 mm, the fin height is generally 12 to 15 mm, and the tube bundle width is 100 to 3000 mm. The finned tube is the core component of the air cooler, and its form and material directly affect the performance of the device. The pipe can be made of carbon steel, copper, aluminum and stainless steel. The fin material is determined according to the use environment and manufacturing process. Most of the industrial pure aluminum is used. Copper is also used in the case of high corrosion resistance or special manufacturing conditions. Or stainless steel.
The fins may be arranged in a lateral or longitudinal direction. The basic forms of finned tubes are: wound sheet, insert type, rolled sheet, sleeve type, welded sheet type, elliptical tube type, turbulent flow type (including spoke type, slotted shape and corrugated shape, etc.). The structure of the pipe box is mainly flange type, pipe block type and manifold type. Generally, the former is used for medium and low pressure, and the latter two are used for high pressure. In order to accommodate the thermal expansion of the tube bundle, one end of the tube box is not fixed, allowing displacement along the length of the tube. Fans usually use axial flow fans.