[How to design a heat exchanger] Heat exchanger design principles Heat exchanger design scheme
Design standard of plate heat exchanger
1. High efficiency and energy saving: its heat transfer coefficient is 3000～4500kcal/m2·°C·h, which is higher than that of shell and tube heat exchanger 3~5 times.
2. Compact structure: the plates of the plate heat exchanger are closely arranged. Compared with other types of heat exchangers, the plate heat exchanger occupies less floor space and space. The plate heat exchanger is only 1/5 of the shell and tube heat exchanger.
3. Easy to clean and easy to disassemble: the plate heat exchanger is clamped by clamping bolts, so it is easy to disassemble and clean, and can be opened and cleaned at any time. High, not easy to scale.
4. Long service life: The plate heat exchanger is made of stainless steel or titanium alloy plates, which is resistant to various corrosive media.
5. Strong adaptability: The plate heat exchanger plate is an independent component, and the process can be increased or decreased at will according to the requirements, in various forms; it can be applied to various different process requirements.
6. No liquid leakage, the sealing groove of the plate heat exchanger is provided with a liquid leakage channel, and various media will not be connected with each other. Even if there is leakage, the medium is always discharged to the outside.
Design description of floating head heat exchanger
With the development of economy, various types and types of heat exchangers have developed rapidly, and new structures , Heat exchangers of new materials are constantly emerging. In order to meet the needs of development, China has established standards for certain types of heat exchangers and formed series. A perfect heat exchanger should meet the following basic requirements during design or selection:
(1) The specified process conditions are reasonably realized;
(2) The structure is safe and reliable;
(3) Easy to manufacture, install, operate and maintain;
(4) Economically reasonable.
Floating Head Heat Exchanger Design
One end of the floating head heat exchanger is fixed to the shell, while the other end of the tube sheet can be placed in the shell. The body floats freely, and the shell and tube bundle are free to expand, so when the temperature difference between the two media is large, there is no temperature difference stress between the tube bundle and the shell. The floating head end is designed as a detachable structure, so that the tube bundle can be easily inserted or withdrawn from the housing. (It can also be designed to be non-removable). This provides convenience for maintenance and cleaning. However, the structure of the heat exchanger is complicated, and the small floating end cap cannot know the leakage during operation. Therefore, special attention should be paid to its sealing during installation.
The structure of the floating head part of the floating head heat exchanger can be designed into various forms according to different requirements. In addition to the free movement of the tube bundle in the equipment, the maintenance, installation and maintenance of the floating head part must also be considered. Easy to clean.
The outer diameter Do of the floating head tube sheet must be considered in the design. The outer diameter should be smaller than the inner diameter Di of the shell, and it is generally recommended that the gap between the floating head tube sheet and the inner wall of the shell be b1=3~5mm. In this way, the tube bundle can be pulled out from the housing after the hook loop from the floating head is removed. For easy maintenance and cleaning. The floating head cover can be assembled after the tube bundle is installed, so the necessary space for the floating head cover should be considered in the design.
The hook and loop play an important role in ensuring the sealing of the floating head end and preventing cross-leakage between media. With the development of the design and manufacturing technology of the Futou heat exchanger, as well as the accumulation of long-term use experience, the structural form of the hook has also been improved and perfected.
The hook and loop are generally split-type structures, which require reliable sealing, simple and compact structure, easy to manufacture and easy to disassemble.
