Heat Transfer Area of ​​Heat Exchanger Tube

Heat exchanger tube refers to a type of equipment used for heat transfer, which are mainly divided into seamless steel pipe and welded steel pipe. They are widely used in various industrial production fields, such as chemical, pharmaceutical and petroleum industries. Heat exchanger tubes can transfer heat between fluids of different temperatures or components through heat exchange technology.

The heat transfer area refers to the surface area of the inner surface of the heat exchanger in contact with the outside world or fluid. It is usually an important parameter for designing and evaluating heat exchangers. The number, diameter, length and arrangement of heat exchanger tubes determine the total area of the heat exchanger tubes.

Classification of heat transfer area of heat exchanger tubes

There are many types of classification of heat transfer area of heat exchanger tubes, which can be distinguished according to different standards, such as direct conduction heat transfer, convection heat transfer, radiation heat transfer, heat transfer between different working fluids, etc. Generally divided into the following three categories:

1. Traditional straight tube heat exchanger (including parallel flow, counterflow, cross flow, etc.).

2. Bent tube heat exchanger (including U-tube, spiral tube, annular tube, etc.).

3. Plate heat exchanger (including semi-circular, flat, S-shaped, etc.).

How to calculate the heat transfer area of the heat exchanger tube

1. Calculation method of heat transfer area of traditional straight tube heat exchanger:

(1) Single tube heat exchanger: St = πDL

Where St is the area of a single tube, D is the outer diameter of the tube, and L is the length of the tube.

(2) Multi-tube heat exchanger: St = πDL×N

Where N is the number of heat transfer tubes.

2. Calculation method of heat transfer area of curved tube heat exchanger:

(1) U-tube: St = πDL + 2.5DL

Where 2.5DL is the area correction factor at the bend.

(2) Spiral tube: St = πDL×h

Where h is the length of the spiral coil, which can be calculated based on actual conditions.

3. Calculation method of heat transfer area of plate heat exchanger:

Due to the different shapes of plate heat exchangers, the calculation methods are also different. Please refer to the relevant manual for details.

Effect of heat exchanger tube length on heat exchange area

There is a direct relationship between the length of the heat exchanger tube and the heat exchange area. When the diameter of the heat exchanger tube is constant, increasing the length of the tube means increasing the surface area of heat exchange. This is because heat exchange mainly occurs on the surface of the heat exchanger tube. Longer heat exchanger tubes provide more surface area, allowing heat to be transferred from one medium to another more efficiently.

Summary

The size of the heat exchange area of the heat exchanger tube depends on the working conditions and requirements of the heat exchanger. Generally speaking, it needs to be calculated according to the specific situation.