Which is better double pipe or shell and tube heat exchanger?

Both double pipe and shell and tube heat exchangers have their own characteristics and advantages, and which one is "better" depends on specific application scenarios and requirements.

Shell and tube heat exchangers generally offer higher heat transfer efficiency, can handle larger heat transfer loads, and are suitable for a wide range of operating conditions and fluids. They are often used in industrial processes where high performance and durability are crucial.

On the other hand, double pipe heat exchangers are relatively simpler in structure, easier to install and maintain, and may be more cost-effective in some cases where the heat transfer requirements are not extremely high. They are sometimes preferred in smaller-scale applications or where simplicity and ease of operation are important factors.

For example, in a large-scale chemical plant with complex fluid handling and high heat transfer demands, a shell and tube heat exchanger might be a more appropriate choice. However, in a smaller food processing facility with relatively modest heat transfer needs, a double pipe exchanger could suffice and offer advantages in terms of simplicity and lower initial cost.

So, it's not a straightforward comparison of which is better, but rather a matter of evaluating the specific needs and constraints of the application to determine the most suitable type of heat exchanger.