High-temperature and high-pressure double-pipe heat exchanger

Abstract

The invention provides a high-temperature and high-pressure double-pipe heat exchanger which is simple and compact in structure, uniform in internal flow temperature distribution, high in heat exchange efficiency, easy to process and manufacture and resistant to high temperature and high pressure and comprises a plurality of groups of double-pipe heat exchange pipes, a first medium pipe box and a second medium pipe box, the casing pipe type heat exchange pipe is formed by combining an outer heat exchange pipe body, an inner heat exchange pipe body and a flow guide rod in a coaxial casing pipe mode, and spiral flow guide convex bodies are arranged on the outer surfaces of the inner heat exchange pipe body and the flow guide rod, so that two media in the heat exchange pipe form spiral annular turbulent flow and rapidly flow in small flow, countercurrent flow heat exchange is formed, and the heat exchange efficiency is improved. The flow paths of the two media are equal, the flow distribution is uniform, the flow paths are increased, and the heat exchange efficiency is improved. The inner heat exchange tube and the outer heat exchange tube can freely stretch out and draw back along with fluid temperature changes and are not fixed mutually, thermal stress can be effectively eliminated, and the heat exchanger is particularly suitable for large temperature difference and high-temperature and high-pressure working conditions of two media.

Description

technical field [0001] The invention belongs to the field of heat exchange, and in particular relates to a high-temperature, high-pressure micro shell-and-tube heat exchanger. Background technique [0002] In the research and development of the fourth-generation high-temperature gas-cooled reactor nuclear power plant and solar thermal supercritical carbon dioxide Brayton cycle power generation, the supercritical carbon dioxide Brayton cycle is considered to be a new, efficient and safe energy cycle system. In the supercritical carbon dioxide Brayton cycle, the heat extractor and regenerator are one of the most important heat exchange components, and their thermal performance has an important impact on the efficiency of the entire cycle and the size of the system. [0003] At present, the heat exchangers used in the second and third generation pressurized water reactor nuclear power plants are generally shell and tube heat exchangers. The traditional shell-and-tube heat exch...

AI Technical Summary

Problems solved by technology

The sealing connection of metal microtubes is usually brazed, but the traditional brazing process is prone to microtube deformation, erosion, virtual welding and other phenomena during processing, which cannot meet the processing requirements

However, the current development of new technologies such as vacuum electron beam brazing of metal microtubes and pulse laser welding have shortcomings such as immature technology, low processing efficiency, and high processing costs.

[0008] Chinese patent, Patent Publication No. CN 103128519A discloses a method and device for manufacturing a microchannel heat exchanger. The heat exchanger tube bundle and the header of the heat exchanger are connected by cold extrusion, which saves raw materials, Energy, the advantages of improving efficiency and reducing costs, but this process is not suitable for high temperature and high pressure working conditions

However, the threaded connection between the heat exchanger tube bundle and the tube sheet cannot meet the conditions of high temperature and high pressure.

[0011] Chinese patent, patent authorization number CN 109654909 B discloses a high-temperature and high-pressure micro shell-and-tube heat exchanger. Although the heat exchanger overcomes the various deficiencies of the above-mentioned heat exchangers, it also has some problems at the same time. After the tube bundle of the heater is changed to a sinusoidal bent tube or a trapezoidal bent tube, although the length of the heat exchange tube increases correspondingly, and the heat exchange area also increases synchronously, the fluid resistance in the microtube also increases greatly, and the tube is bent After being folded, the internal flow channel at the bend is easy to narrow, which not only affects the flow rate but also is easy to block; on the other hand, the diameter of the microtube is controlled between 1mm and 3mm, and it is not easy to seal the two ends of the tube bundle; although, All heat exchanger tube bundle flows are equal, which can ensure uniform flow distribution on the tube side, but the shell side flow is not equal to each tube bundle, and it is difficult to ensure uniform flow distribution on the shell side

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