Hang Zhou Dawn Air Conditioning Co .,Ltd.

With economic development, various types of heat exchanger types and rapid development of new structures, new materials, heat exchangers are emerging. In order to meet its development needs, certain types of heat exchangers has established a standard, forming a series. Improve the heat exchanger in the design or selection should meet the following basic requirements:
(1) under reasonable conditions to achieve;
(2) structural safety and reliability;
(3) ease of manufacturing, installation, operation and maintenance;
(4) economically rational.
Floating head condenser coils tube plate and the shell one end fixed, while the other end of the tube sheet can be freely floating in the shell, shell and tube bundle of the expansion is free, so the larger the temperature difference when the two media, the discipline and temperature difference between the shell does not produce stress. Floating removable side designed to structure, so that tubes can be easily inserted into or out of the shell. (Also can be designed to not be demolished.) Such as maintenance, cleaning more convenient. However, the heat exchanger structure is more complex and cap the floating end of a small leak in the operation can not know the situation. Therefore, pay special attention when installing the seal.
Floating Head Floating Head Heat Exchanger part of the structure, according to different requirements can be designed in various forms, in addition to the equipment must be considered within the tubes can move freely, it must also take into account the floating head portion of maintenance, installation and cleaning easy.
Must be considered in the design of the outer tube sheet floating head Do. The outer shell should be less than the diameter Di, the general recommendation floating head tube plate and the shell wall space b1 = 3 ~ 5mm. Thus, when the floating head out of the hook ring removed, you can shell out from the bundle. In order to facilitate the maintenance, cleaning. Floating head covered in the bundle before the assembly is loaded, it should be considered in the design of floating head covered in the assembly to ensure that the necessary space.
Circle hooks to ensure that floating head on the side of the seal to prevent leakage of media between the strings play an important role. With Fu head heat exchanger design, manufacturing technology, and the accumulation of long experience, forms the structure of circle hooks were not of the improvement and perfection.
Ring off the hook for the structure usually require sealing, reliable, simple, compact, easy to manufacture and easy disassembly.
Floating head heat exchanger with its high reliability and wide adaptability, in the long process of accumulating a wealth of experience. Although in recent years by the emerging challenges of the new evaporator coils, but in turn continue to promote its own development. So far the cast in a variety of heat exchanger dominant.
Tube heat exchanger heat transfer surface composition, size and shape of the heat pipe has a great influence. When using small diameter pipe, heat exchanger heat transfer area per unit volume of larger, more compact equipment, the unit consumption of less heat transfer area of the metal, heat transfer coefficient is higher. But the trouble, the tube easy to scale, easy to clean. Large-diameter pipe used for viscous or dirty fluids, small-diameter tube for cleaner fluid.
Pipe material selection should be based on media pressure, temperature and corrosive to determine.
Heat exchanger tubes are arranged in the tube sheet is not considered compact equipment, but also taking into account the fluid nature of the structural design and manufacturing aspects. Tubes arranged in the form of a standard tube sheet there are four: equilateral triangle and the angle triangle arrangement with the shell media for cleaning, and does not require mechanical cleaning of the occasion. Corner of the square and the square array, enabling management to form a bridge between the straight channel, easy to use mechanical cleaning, generally used for cleaning between the tube bundle can be removed from the occasion.
Another way for the multi-tube heat exchanger, often in combination order method, the process is generally used for each triangular arrangement, and the process is often used between the square array, so that arrangements to facilitate bulkhead position.
When the heat exchanger with larger diameter pipe is large, have to bow in the bundle space around the tubes as far as configuration. This will not only effectively increase the heat transfer area, but also to prevent the fluid in the shell short circuit in the bow to the heat transfer within the region adversely affected.
Tube pitch control panel to consider the choice of both the compact structure, heat transfer, but also consider cleaning the tube sheet strength and the space required for the outer surface of the tube. In addition, the board must also consider the fixed tube in tube method. If the spacing is too small, when the welded connection, two adjacent weld pipe too close to the quality of the weld heat affected not easy to be guaranteed; the use of a Expansion, tube sheet extrusion pressure may cause excessive deformation occurred, loss of pipe and the binding force between the tube sheet. The tubes generally use the center distance of not less than 1.25 times the pipe diameter.
When the heat exchanger and more to be larger, while the tube is too long do not, you have to increase the diameter of the shell to order more of the pipe. At this time management process to improve flow, increase the heat transfer effect, required to bundle sub-process, so that the process fluid flow through the tubes in turn.
In order to make multi-tube pass heat exchanger can be at one end or both ends of the tube box in the placement of a certain number of divisions, respectively.