How to keep the good performance of the air heater
Everyone knows that the heater for a long time, its good performance will be affected and weakened, it will work in the late effects of efficiency, if all change and uneconomical, so we need to keep on in other aspects of air heater performance. The following is some of our experience in maintaining performance when some air heaters are used.
A gas entrance, increase the flow rate of the air heater, air heater can enhance convective heat transfer, and reduce the surface temperature of the air heater in the heating element, not only conducive to the extension of the air heater heating element service life, but also makes the air electric heater heat loss is reduced, so the efficiency of air heat exchanger improved. But if the speed is too large, so that the pressure loss increased sharply, which will improve the efficiency of heating is unfavorable.
Two, if the other conditions are the same, the change of surface load, heating element of air heater in wall temperature show linear change, if the surface load increases, the wall temperature will increase the heating element, the heating element will reduce the service life of the air heater, but if the surface load is too small, the wall temperature is too low, the efficiency of air the heater of the heat exchanger were reduced, so the surface load of air heater in the heating element selection is more important.
Three, air heater in the air temperature of T2 increases, due to the air viscosity increased, the gas Reynolds number decreases, the convective heat transfer intensity decreased, while increased the surface temperature of air heater in the heating element, the heat loss increased, thereby reducing the efficiency of heat exchanger. When the T2 is raised too much, the surface temperature of the electric heating element will also increase greatly, causing the general electric heating element to be unable to bear. Therefore, the increase of T2 is usually limited by the heat resistance of the electric heating element in the air heater.