1. Increasing the gas inlet flow rate of the air heater can strengthen the convection heat exchange of the air electric heater, and reduce the surface temperature of the electric heating element in the air heater, which is not only conducive to prolonging the service life of the electric heating element of the air heater, but also reduces the heat dissipation loss of the air heater, so the efficiency of the air heat exchanger is improved, but if the speed is too large, the pressure loss increases sharply, which will not be conducive to the improvement of heating efficiency.
2. If other conditions remain unchanged, change the surface load, the wall temperature of the electric heating element in the air heater will change in a straight line, if the surface load increases, the wall temperature of the electric heating element will increase, which will reduce the service life of the electric heating element in the air heater, but if the surface load is too small, the wall temperature is too low, the efficiency of the air heater heat exchanger is reduced, so the choice of the surface load of the electric heating element in the air heater is more important.
3. When the final air temperature T2 in the air heater increases, due to the increase of air viscosity, the gas Reynolds number decreases, so that the convection heat exchange strength decreases, the surface temperature of the electric heating element in the air heater rises at the same time, and the infrared carbon and sulfur analyzer increases the heat dissipation loss, thereby reducing the efficiency of the heat exchanger. When T2 is raised too much, the temperature of the surface of the electric heating element will also rise greatly, so that the general electric heating element cannot withstand it, so the increase of T2 is usually limited by the heat resistance of the electric heating element material in the air heater.
