Air heater heating rate can not be controlled

There are many friends who use air heaters. Most of the questions are whether the air heater is very energy-saving, can the heating rate be adjusted? The air heater temperature rises, the air viscosity increases, the gas Reynolds number decreases, and the heat transfer intensity decreases. The surface temperature of the air heater rises and the heat loss increases.

This problem depends on the structure of the air heater. Air heater manufacturers can only change the frequency of the AC, which will change the speed of the motor, the air heater does not rotate, and the frequency of the water heater does not control the heating speed. We have two relatively simple methods, the transformer voltage change is small, the advantage is multi-stage regulation, the disadvantage is that the circuit structure is more complicated and the production cost is high. The half-wave rectifier is used to change the value of the alternating current to achieve the purpose of changing the heating power and heating speed. The method has the advantages of simple circuit structure and convenient operation. The heating rate of the air heater is mainly such that it should be reasonable. To improve the overall efficiency of the air heat exchanger, we can do the following: First, adjust the shape of the fan and the baffle by the involute shape or Archimedes vortex, and secondly, the shape of the square The chamfering treatment makes it a volute to reduce the wind resistance. Thus, by the above two measures, the overall efficiency of the air heat exchanger can be improved to achieve the goal.