Shell-and-tube heat exchanger

Abstract

The invention discloses a tube heat exchanger. It includes a cylindrical shell and a tube sheet, and the shell walls at both ends of the cylindrical shell have high-temperature flue gas inlets and outlets respectively. There are air inlets and outlets at both ends of the cylindrical shell respectively. Its characteristic is that the tube sheet contains two outer tube sheets and two inner tube sheets, and the tube holes on the outer and inner tube sheets correspond to each other. Stainless steel tubes are connected between one outer tube plate and the corresponding tube holes on the adjacent inner tube plate, and carbon steel pipes are connected between the other outer tube plate and the corresponding tube holes on the adjacent inner tube plate. There are openings on the cylindrical shell at the outer sides of the two inner tube sheets, and there are covers outside the two openings, so that the inner cavity of the cylindrical shell where the stainless steel tube is located communicates with the inner cavity of the cylindrical shell where the carbon steel tube is located. The opening and the cover are on the same side of the high-temperature flue gas inlet. The shell and tube heat exchanger has high heat exchange efficiency and long service life. It is suitable for heating air by using high-temperature flue gas after burning natural gas, coal or oil.

Description

technical field [0001] The invention relates to a heat exchanger. Specifically, it is a serial shell and tube heat exchanger that uses high-temperature flue gas after burning natural gas, coal or oil to heat air. Background technique [0002] The temperature of the flue gas discharged from the combustion of natural gas, coal or oil is as high as 1000°C. If it is not recycled, it will cause a waste of energy. Therefore, people use shell and tube heat exchangers to recycle the exhausted high-temperature flue gas. The traditional tube-and-tube heat exchanger is a single-tube heat exchanger. This single-tube heat exchanger includes a cylindrical shell, and the shell walls at both ends of the cylindrical shell are respectively processed with high-temperature flue gas inlets and high-temperature The flue gas outlet, the high-temperature flue gas inlet and the high-temperature flue gas outlet are respectively located on the shell wall on the opposite side of the cylindrical shell...

AI Technical Summary

Problems solved by technology

However, due to the poor high temperature corrosion resistance of carbon steel pipes, the service life of the heat exchanger will be greatly shortened.

[0003] Since the traditional tube-and-tube heat exchangers are all single-tube tube-and-tube heat exchangers, the connection between the two ends of the heat exchange tubes and the tube sheet is expansion joint and welding. The temperature of the tubes is high, and the thermal expansion of the tube sheet and the tubes is different, so that the tube sheet exerts pressure on the tubes, so that the strength of the weld between the tubes and the tube sheet decreases at high temperature and cracks

Therefore, the traditional shell and tube heat exchanger is easily damaged and has a short service life

[0004] And because the air entering from the air inlet is directly sent to the tubes for heat exchange, the air is not easy to contact with the tube walls of the tubes when it flows in the column, so that the heat exchange effect is not sufficient, and in this way, it will also reduce the performance of the heat exchanger. heat transfer efficiency

Images