Excessive fins can cause the following problems: 1. Whe […]
Excessive fins can cause the following problems:
1. When the heat transfer area of the fin is doubled, the heat transfer coefficient cannot be doubled, but a discount is required, which is generally (0.9---0.7), and the higher the fin, the discount value. The bigger, even falls below (0.5). This shows that the higher the fins, the lower the fin efficiency and the lower the economics of the fins.
2. If the fins are too high and too dense, it is easy to cause ash accumulation problems, and it is difficult to remove dust.
3. The fins are too high and too dense, which will increase the process difficulty and increase the processing cost.
For a 1-meter-long pipe, the total heat transfer area after the fin is increased is A, and when the light pipe area when the fin is not increased is A0, A/A0 is a multiple of the area expansion, which is called "winging." ratio". The appropriate wing ratio is appropriate, which is determined by the application conditions and optimized design. In general, finned tubes used in energy engineering have a wing ratio of 5---12, while in air-conditioning and air-cooling industries, the fin ratio is between 15 and 22.