Apr 19, 2021
The fin type air heater is composed of a perforated plate frame and a radiating pipe. It is one of the most widely used heat exchange equipment for industrial air heating. This type of steam air heater is often used when the fluid at one end is at a high pressure or the heat transfer coefficient is much larger than the other end.
The core heat exchange element of the finned air heater is a finned tube. Why add fins to the original surface and use finned tubes? Because the inside and outside of the tube are convective heat transfer between two mediums, for example: in a gas-liquid heat exchange system, the heat transfer coefficient of the liquid inside the tube is much larger than the heat transfer coefficient of the gas outside the tube, so fins are added outside the tube to increase the air The heat exchange area on the side, thereby greatly improving the heat exchange effect of the steam heater.
When people choose air heaters, the heat exchange effect is an important reference factor. At this time, there is usually such a question: "Since adding finned tubes can increase the heat exchange area and improve the heat exchange effect of the finned steam air heater, is it better to add more fins?"
The answer is of course no. The more fins are not the better, nor the higher the better. According to the experimental results, when the heat transfer area of the steam heater fin doubles, the heat transfer coefficient cannot be doubled, but a discount is required, and when the fin is higher, the discount is greater or even reduced to 0.5 Hereinafter, this shows that after the fin reaches a certain height, the increased area has less effect on heat transfer, and the economic efficiency of adding fins also decreases.
