The main method of increasing the k value of the plate heat exchanger is to increase the degree of fluid disturbance on the surface of the heat exchange medium on both sides of the plate. The plates of plate heat exchangers are usually processed into herringbone corrugated plates. For herringbone corrugated sheet, the size of the herringbone angle has a great influence on heat transfer and fluid resistance. Plates with large herringbone angle have high heat transfer coefficient and large fluid resistance; on the contrary, plates with small herringbone angle have low heat transfer coefficient and resistance.
The corrugated heat transfer effect of the herringbone angle is good, the smaller the angle or the larger the angle, the lower the heat transfer efficiency. Usually the cooler and the cylinder jacket water cooler use 120° herringbone angle plates to achieve good replacement. hot.
In the lubricating oil cooler, since the viscosity of the lubricating oil is higher than that of water, if all the plates with a large angle of 120° are used, the fluid resistance will be large, while the heat transfer coefficient of the plates with a small angle of 60° is used. Low. Therefore, oil coolers often use a combination of two types of plates.
Each specification of plate has at least two plate types, using thermal mixing technology, which can integrate the heat transfer and pressure drop of the plate heat exchanger to make it run at the working point. Internal bypass, dual flow channel technology and unequal flow cross-sectional area assembly provide a solution for conditions with large differences in medium flow on both sides. Different models have deep corrugations, shallow corrugations, large angles, small angles, etc.