Heat transfer area and configuration requirements of spiral plate heat exchanger
作者:Tianli biology点击:788
The heat transfer coefficient of spiral plate heat exchanger is high when it is used. To a certain extent, due to the fluid flowing in the spiral channel, turbulence can be achieved at a lower Reynolds number (generally re = 1400 ~ 1800, sometimes as low as 500), and a higher flow rate (2m / S for liquid and 20m / s for gas) can be selected, so the total heat transfer coefficient is large.
The spiral plate heat exchanger is not easy to be blocked during operation. Due to the high flow rate of the fluid, the suspended solids in the fluid are not easy to deposit, and any deposit will reduce the cross section of the single channel, so the speed will increase and the blocking area will be scoured. Therefore, the spiral plate heat exchanger is not easy to be blocked.
The spiral plate heat exchanger can effectively use the low temperature heat source to control its temperature, which is mainly due to the long flow channel and the complete countercurrent of the two fluids. Compact structure. The heat transfer area per unit volume is three times of that of tube heat exchanger.
The spiral heat exchanger is composed of one or more spiral wound tubes arranged on the formed shell. It is characterized by compact structure, heat transfer area of straight tube with large and small thermal stress, but not easy to clean, and can be used for heating or cooling high viscosity fluid. By guiding the fluid flow in the tube so as to approach the spiral groove of the wall of the fluid groove cyclone separator, the thickness of the boundary layer can be reduced; when the fluid flows along a part of the axial direction of the wall, they produce a bulge through the axis of the spiral groove in the vortex, resulting in the disturbance of the boundary layer and the stratified fluid in the boundary layer.
Spiral plate heat exchanger thus speeds up the body from the wall to the heat transfer fluid. Spiral grooved tube to tube boiling and condensing heat transfer inside and outside the tube can play a role in strengthening. Because the spirally grooved tube has an uneven surface, the condensate is easy to drain into the surface tension tube. The condensation spirally grooved tube is mainly dominated by gravity, surface tension and viscous force, mainly on the outer surface of the tube groove. The surface tension is a constant times of gravity. When the horizontal section of the surface tension of the outer tube in the liquid is pulled by condensation, the upper horizontal part is used to reduce the condensate The amount to notch root, film thinning. Condensation is discharged from the bottom of the tank by the rapid formation of pressure and tension in the gravity flow tube.