Views:0 Author:Site Editor Publish Time: 2020-04-30 Origin:Site
1) High heat transfer coefficient. The flow path of the plate heat exchanger is small, the plate is wave-shaped, and the cross-section changes are complicated, so that the flow direction and flow rate of the fluid are constantly changing, which increases the disturbance of the fluid, so it can reach turbulent flow at a small flow rate, and has a high Heat transfer coefficient. It is especially suitable for liquid-to-liquid heat exchange and fluid flow heat exchange with large degree of fluid.
2) Great adaptability. The required heat transfer area can be achieved by adding or removing plates. A heat exchanger can be divided into several units, which can be adapted to heat or cool several fluids at the same time.
3) Compact structure, small size and few consumables. The heat transfer area per cubic meter of volume can reach 250 m2, and only 15 kg of metal per square meter of heat transfer surface.
4) High heat transfer coefficient and low metal consumption make the heat transfer efficiency up to 85% -90% or more. 5) Easy to take apart, wash and repair.
6) The scale factor is small. Due to the large flow disturbance, the dirt is not easy to deposit; the plate material used is good, and there is little corrosion, which makes its dirt coefficient value small.
7) The plate heat exchanger mainly uses metal plates, so the price of raw materials is lower than that of the same metal pipes.
1) Poor sealing, easy to leak. It is troublesome to change the gasket frequently.
2) The operating pressure is subject to certain restrictions, generally not exceeding 1MPa
3) The operating temperature is limited by the temperature resistance of the gasket material.
4) The flow channel is small, not suitable for gas-to-gas heat exchange or steam condensation.
5) Easy to block, not suitable for fluids with suspended matter.
6) The flow resistance is larger than the shell and tube type.
As a kind of heat exchanger, plate exchange is realized by the heat exchange between water and fins, and its efficiency is greatly related to the flow velocity and temperature difference of water in the flow path between fins. Once the flow rate changes, the heat transfer coefficient also changes, and the amount of change is large. Therefore, the board replacement can only be used in a system with a stable load (to be precise, flow) (a constant flow heating system is a typical application). And the flow of domestic hot water changes quite drastically during the day, so it is extremely unsuitable to use plate replacement. The volumetric heat exchanger is used to store a certain amount of hot water, and can cope with the flow rate change of the user side to a considerable extent. In calculations, the plate replacement type is selected according to the maximum flow rate per second, and the volumetric type is selected based on the maximum flow rate per hour.
The volumetric type has a certain water storage capacity, which can be used to supplement the peak water, and the plate type may be considered according to the "immediate type".