Working principle of finned tube heat exchanger

The finned tube heat exchanger is a heat exchange equipment that uses hot water or steam for heating in industry. The heat exchange area is enlarged by adding fins to the smooth base tube.

Its structure is a combined unit composed of a perforated plate frame and a steel heat dissipation pipe, which is suitable for large and medium-sized heat exchange systems such as air heating, cooling and waste heat recovery.

The working principle and structure of the finned tube heat exchanger are closely related. In short, it mainly uses heat conduction, heat radiation and convection.

The following is a detailed introduction:

1. Introduction of finned tube heat exchanger

The medium of the finned tube heat exchanger is mainly divided into two types: gas and liquid. The gas includes steam or high-temperature exhaust gas; the liquid includes hot water or heat transfer oil.

In actual use, most of them are steam and hot water. Steam loses heat quickly and needs to maximize heat utilization in a short period of time. Therefore, baffles are provided at both ends of the heat exchanger, and the heat dissipation pipes are interconnected. It is beneficial to improve thermal efficiency; on the contrary for hot water, multi-circuit row pipes are set up, arranged in fork rows, and connected with a separate elbow pipe to increase the residence time of hot water and improve heat exchange efficiency.

2. The working principle of the finned tube heat exchanger

When the hot water or steam passes through the heat exchange base tube of the finned tube heat exchanger, the heat is transferred to the inner wall of the base tube by convection,

The inner wall transfers heat to the outer wall and fins through heat conduction, and the outer wall and fins finally heat the surrounding air by forced convection and radiation, so as to achieve the purpose of heating.

3. Structural characteristics of finned tube radiator

    1. The finned tube radiator adopts a steel double-circuit (two-row) or multi-circuit (four-row, six-row) structure. The finned tube adopts a steel-aluminum cold-rolled composite forming process. Thickness of 0.3mm, spacing of 3mm, high pressure bearing, corrosion resistance;

    2. The radiating pipes of the fin-and-tube heat exchanger are arranged in a fork row and connected with a separate elbow pipe;

    3. SRZ finned tube radiator has good heat exchange performance and can be used instead of steel finned tube radiator;

4. Heat pipe features:

Heat dissipation area: 0.64m²/m

Rib factor: 14.56

Rib pass coefficient: 15.8

Net ratio: 0.53