The plate heat exchanger is a high-efficiency heat exchange device composed of a plurality of corrugated heat transfer plates at a certain interval by welding or pressing by a rubber gasket.What is the reason for the large pressure drop of plate heat exchanger?
(1) The operation system pipeline has not been blown and washed properly, especially many dirt (such as welding slag) in the newly installed system pipeline enters the inside of the plate heat exchanger. Because of the narrow cross-section area of the flow channel of the plate heat exchanger, the sediment and suspended matter in the heat exchanger accumulate in the corner hole and the diversion zone, resulting in a large reduction of the flow channel area at the corner hole, resulting in a major loss of pressure in this part.
(2) After a period of operation, the pressure drop of plate heat exchanger is too large due to scaling on the surface of plate. For example: our factory provided BR10 plate heat exchanger for customers, which is used in central heating system of water-water heat exchange. The design temperature of primary water supply is 130℃. In the design and selection of heat exchanger, the heat transfer derivative is high, approaching 5 500 w/(rn.K), but it should be 3 500 w/(rn.K). At the same time, when the pump is selected, the flow margin of the design unit is too large, which causes the flow velocity between the secondary side plate of the heat exchanger to exceed 1 m/s, and the actual operating pressure drop to be 0.2-0.3 MPa, which makes the hydraulic balance of the secondary network seriously imbalanced.
(3) When the plate heat exchanger is first selected, the area is too small, which results in the high flow velocity between plates and the high pressure drop.