Wound tube type heat exchanger for low-temperature circulating methanol coolers

Abstract

A wound tube type heat exchanger for low-temperature circulating methanol coolers is mainly applied in the coal chemical industry of coal gas, coal methanol and the like, including the field of low-temperature gas purification technology and low-temperature gas liquefaction and separation technology, such as the negative 70 DEG C low-temperature methanol washing process, the wound tube type heat exchanger is double-tube bundle helical coil type heat exchange equipment which is formed after heat exchange tubes are wound layer by layer, and the double-stream wound tube type heat exchanger mainly adopts shell side cold methanol to cool two streams of tube side methanol with different temperatures, so that the temperatures of the two streams of tube side methanol are respectively decreased. The wound tube type heat exchanger is provided with four separate ring-shaped separate headers which are arranged in a shell and are formed by curved thick-walled round tubes, and the inlets and outlets of two wound tube bundles are directly connected with the ring-shaped thick-walled round tube headers, so that the whole double-stream heat exchanger without tube plates is formed. The heat exchange efficiency of a low-temperature circulating methanol cooler can be increased, the heat exchange area of the low-temperature circulating methanol cooler per unit volume can be enlarged, and the complex wound tube bundles can be conveniently produced, mounted and repaired.

Description

technical field [0001] The invention relates to a coiled tube heat exchanger for a low-temperature circulating methanol cooler, which is mainly used in the fields of coal chemical industry such as coal-to-gas and coal-to-methanol, and includes the technical fields of low-temperature gas purification and low-temperature liquefaction separation such as -70°C low-temperature methanol washing process. Background technique [0002] The coiled tube heat exchanger for low-temperature circulating methanol cooler is a double-bundle spiral coil heat exchange equipment formed after the heat exchange pipe is wound layer by layer. It is mainly used for methanol cooling at -43.29℃ on the shell side And the tube side -17.43°C methanol two tube bundles, so that the temperature drops to -36.24°C and -36.21°C respectively, and the shell side methanol temperature rises to -35.87°C heat exchange process. The design pressure of the shell side is less than 1.0MPa, the temperature is between +60~-...

AI Technical Summary

Problems solved by technology

In addition, the traditional coiled tube heat exchanger usually adopts the method of directly welding the two upper and lower integral large tube plates with the two ends of the shell (5) to fix the tube plate and the coiled tube bundle (3), the coiled tube bundle (4), or use tube The plate and the head form the tube box mode. Once the tube bundle of the heat exchanger breaks, it is often necessary to destroy the whole tube bundle because the winding tube bundle (3), the winding tube bundle (4), the tube sheet and the shell (5) are welded together. The welded part of the plate and the tube sheet and the shell (5) enters the shell (5) for maintenance, which causes the heat exchanger coiled tube bundle (3) and coiled tube bundle (4) to be easily damaged. Replace the coiled tube bundle (3) and coiled tube bundle (4) It is difficult to increase, but this method is easy to damage the tube sheet. After the tube sheet is damaged, it is necessary to replace the tube sheet and fix the winding tube bundle (3) and the winding tube bundle (4). Methanol itself is a flammable and explosive chemical , large-scale maintenance can easily lead to potential safety hazards, the maintenance process is complicated, and even scrapped because it is often impossible to maintain

In addition, the form of direct welding between the integral tube sheet and the shell (5) increases the difficulty of manufacturing and assembly, and the requirements for internal weld welding are very high, which may easily lead to weld leakage

Secondly, because the wound tube heat exchanger is used in a low temperature environment, the internal pipe winding process is complicated, there is no general design standard, and there is no unified design calculation method, and there are great differences with different technological processes or physical parameters. Therefore, , the coiled tube heat exchanger for the low-temperature circulating methanol cooler has not yet been standardized

Furthermore, since most heat exchanger tube boxes cannot participate in the entire heat exchange process, the heat exchange process can only rely on the tube side and the shell side for heat exchange, and the tube boxes at both ends of the heat exchanger are only used as auxiliary parts and do not participate in the entire heat exchange process. Thermal process, the effective heat transfer height of the heat exchanger is affected to a certain extent

Finally, due to the fact that there are many ways to intertwine the twin-stream heat exchange coiled tube bundle (3) and coiled tube bundle (4) in the coiled tube heat exchanger for the low-temperature circulating methanol cooler, there is no uniform tube coiling mode and theoretical design calculation method. Due to the computer-aided calculation process, it brings obstacles to the scientific calculation process of the coiled tube heat exchanger used in the low-temperature cycle methanol cooler

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