Multistage finned tube capable of restraining frost formation and intensifying natural convection

Abstract

The invention discloses a multistage finned tube capable of restraining frost formation and intensifying natural convection. The multistage finned tube comprises a central tube, a plurality of primary longitudinal fins which are distributed in a star manner and secondary fins connected with the primary longitudinal fins. The surfaces of the secondary fins are parallel to the axis of the central tube, and the outer space of the central tube is divided into a plurality of longitudinal parallel channels by the secondary fins. The finned tube can form a sealed air flow channel through the primary fins and the secondary fins. The secondary fins of the finned tube can prevent steam in air from being conveyed to the roots of the fins from the outer space of the finned tube, the steam can only enter from the top space of the finned tube, and the frost formation is restrained. The large specific surface area of the secondary fins enlarges the distribution area of frost, improves the frost distribution evenness, prevents frost from piling at the root of the central tube and the roots of the primary fins, enables the frost thickness on the surfaces of the fins to become thin, reduces the heat transfer resistance and quickens the defrosting speed. By means of the large specific surface area of the secondary fins, the heat exchange area on the air side is enlarged, and heat exchange is intensified.

Description

technical field [0001] The invention belongs to the technical field of heat exchangers, in particular to an air-temperature vaporizer for vaporizing low-temperature fluids such as liquefied natural gas, liquid oxygen, and liquid nitrogen. Background technique [0002] As the cleanest fossil energy, natural gas has gradually increased its proportion in the world's energy structure. Natural gas is stored and transported in the form of liquefied natural gas (LNG), which has the advantages of low cost, convenient use, safety and reliability. The LNG industry will become a key industry in China's future energy development. In recent years, my country's LNG industry has developed rapidly, and the number of domestic LNG receiving stations and gasification stations has increased rapidly. [0003] In practical application, the liquefied natural gas needs to be vaporized and brought to normal temperature before it can be used. The gasifier is the core equipment of the gasification ...

AI Technical Summary

Problems solved by technology

This is because: (1) The overall heat transfer performance of the existing LNG air-temperature gasifier is poor, the equipment occupies a large area, is heavy, and has a large initial investment, making this type of gasifier generally used for gasification Small gasification station, less used in LNG receiving terminal

(2) The air-temperature gasifier is greatly affected by the external environment

In the winter in northern China, the air-heated gasifier is seriously frosted, resulting in the outlet temperature of the gasifier being too low, which cannot meet the needs of use

(3) After the air-temperature gasifier has been running for a period of time, it is necessary to use the spare gasifier to shut down and defrost, which increases the operating cost of the equipment

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