How to maintain good performance of finned heater?
Everyone knows that the heater has been used for a long time, and its good performance will inevitably be affected and weakened. This will affect the work efficiency in the later stage. It is not cost-effective to replace it all, so we need to maintain the Air heater performance. Here are some of our experiences with maintaining performance when using finned heater.
1. Increasing the flow velocity of the gas inlet of the air heater can enhance the convective heat transfer of the finned heater, and reduce the surface temperature of the electric heating element in the air heater, which is not only conducive to extending the service life of the electric heating element of the air heater, but also The heat loss of the finned heater is reduced, so the efficiency of the air heat exchanger is improved, but if the speed is too large, the pressure loss will increase sharply, which will not improve the heating efficiency.
2. If other conditions remain unchanged, changing the surface load, the wall temperature of the electric heating element in the air finned heater will change linearly. If the surface load increases, the wall temperature of the electric heating element will increase, which will reduce air heating. The life of the electric heating element in the 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 temperature T2 of the finned heater increases, the air viscosity increases and the gas Reynolds number decreases, which reduces the strength of convective heat transfer. The surface temperature of the electric heating element in the air heater rises at the same time, which increases the heat dissipation loss, thereby reducing This improves the efficiency of the heat exchanger. When T2 is increased too much, the temperature of the surface of the electric heating element will also be greatly increased, making general electric heating elements unbearable. Therefore, the increase of T2 is usually limited by the heat resistance of the electric heating element material in the air heater.
