In the closed-loop cooling water system, the cooling water of the plate heat exchanger and the cooled water convection on both sides of the corrugated plate, and the corrugations adopt herringbone corrugations. The corrugations of these heat transfer plates are obliquely crossed, and adjacent heat transfer plates have corrugations with the same inclination angle but different directions. The cross-sectional area along the flow direction is constant, and turbulence is caused by the change of the flow channel shape due to the continuous change of the flow direction. What is the application of plate heat exchanger in closed-loop cooling water system?
(1) Generally, the corrugation depth of heat exchanger plates is 3-5mm, and the flow velocity in the turbulent zone is about 0.1-1.0m/s. The plates are very thin, with a thickness of 0.4-1mm. The adjacent plates have herringbone grooves in the opposite direction. The intersection of the two grooves forms a contact point, which can also eliminate vibration and promote turbulence and heat exchange. At the same time, internal leakage caused by fatigue cracks is eliminated. The herringbone corrugated board has a high degree of turbulence. The high turbulence can also give full play to the cleaning effect. It can be particularly effective to minimize the deposited dirt. When the liquid water quality is poor and contains suspended solid particles, sundries and water plants, due to the gap between the plates It is very narrow. It is necessary to ensure that all particles above 2mm are filtered out before entering the heat exchanger. If the filter does not function effectively, it is prone to blockage.
(2) In the closed-loop cooling water system, the cooling water side and the cooled water side flow uniformly and turbulently, and the two fluids flow in opposite directions. The turbulence is caused by the action of the ripples, resulting in high heat transfer rate, high resistance pressure drop and high Shear stress field, which will inhibit the formation of dirt on the heat transfer surface. The heat transfer coefficient is generally 5000-6000w/(m2.k).
(3) The two medium flow channels are basically the same and the heat transfer efficiency is high. The plate heat exchanger can greatly reduce the cooling water volume. Generally, the ratio of the cooling water volume to the cooled water volume is 0.8-1.1:1, which can reduce the cost of pipeline valves and pumps .