Plate heat exchanger needs to be re-inspected according to the requirements of the clamping plate, if in order to further improve the heat transfer capacity needs to be added when the plate. Should take into full account the deformation strength of the fixed platen and the activity of the platen, using the same level of experimental pressure, the number of plates increased at the same time as the bolt preload needs to be increased, when both sides of the elastic deformation of the platen beyond the permissible range of the seals of the plane of compression of the radial sliding, the formation of the mismatch, at this time, the seal fails, the two media leakage or internal liquid with each other, and can not be used normally.
For a long time not put into use heat exchanger is usually appropriate to relax the screw tension, plate and gasket after long-term pressure to lose the necessary elasticity, sealing is easy to fail, reduce service life. Heat exchanger of the compression bolts are distributed force, the installation of the plate before the installation of the diagonal clamping, and real-time measurement of the distance between the two compression plate, to ensure that the two compression plate is basically in a parallel state, the four corners of the parallelism deviation is less than 2%, pre-tighten the bolts according to the order of the figure shown in the order.
In order to efficiently play the heat transfer efficiency, plate heat exchanger of the two media cycle using the full countercurrent flow, in practice, taking into account the offline spare parts supporting the hydraulic system, will be a larger heat transfer area of the exchanger as a general-purpose parts reserve, the media interface will be different in the direction of the interface, hot and cold media interchangeable interfaces or the same media in and out of the use of the opposite direction, etc., this type of problem will not be unfavourable to the formation of sealing, but it will have some impact on the heat exchange efficiency. Efficiency has a certain impact, as shown in the figure: countercurrent when the temperature difference between the two media is small, heat loss is small, high heat transfer efficiency; downstream when the temperature difference is large heat transfer efficiency is low.
(1) plate heat exchanger on the horizontal tension of the connecting screw has strict requirements, especially in the lifting of its own weight of high-power heat exchanger, you must use a dedicated lifting position, non-conventional lifting method of screw force structure has a certain degree of damage, heat exchanger plate is prone to misalignment. In addition, the large plate heat exchanger equipment in the full cold, hot media, the media itself will be a substantial increase in weight, the installation of equipment must also be placed on a certain level.
(2) heat exchanger hot and cold media for heat exchange at the same time, the formation of exposed heat dissipation plate also exists with the ambient air heat exchange process, heat exchanger around the necessary space usually need to be reserved around the position (lm or more), in order to form a smooth air flow environment, conducive to the play of the heat transfer capacity.
