Heat exchange tube, heat exchanger tube core, heat exchanger and manufacturing method

Abstract

The application discloses a heat exchange tube comprising a first hollow tube and a second hollow tube, and the first hollow tube comprises a first end and a second end; the second hollow pipe comprises an open end and a closed end, and the first hollow tube is arranged in the second hollow tube; a gap is formed between the outer wall of the first hollow tube and the inner wall of the second hollow tube, and the first end of the first hollow tube extends out of the open end of the second hollow tube; the second end of the heat exchange tube is separated from the inner wall of the closed end ofthe second hollow tube; and the open end of the second hollow tube of the heat exchange tube and the middle part of the second end of the first hollow tube are wound into a spiral shape around a center. The application further discloses a heat exchanger tube core using the heat exchange tube, a heat exchanger and a manufacturing method thereof. By adopting the spiral winding type and sleeve typeheat exchange tubes, the heat exchange area can be increased, so that the heat exchange efficiency is improved; meanwhile, stress deformation and weld joint cracking due to heat expansion of the heatexchange tubes in use of the heat exchanger tube core and the heat exchanger are avoided; and the possibility of dew point corrosion can be reduced.

Description

technical field [0001] The invention relates to the field of waste heat recovery in industries such as oil refining and chemical industry, and in particular relates to an improved heat exchange tube, a heat exchanger core, a heat exchanger and a manufacturing method for improving heat exchange efficiency. Background technique [0002] The countercurrent spiral wound tube heat exchanger has high heat exchange efficiency and is widely used in various fields. However, taking the practical application of heat exchange between acidic high-temperature flue gas and low-temperature medium as an example, the acidic high-temperature flue gas goes through the shell side, and the low-temperature medium goes through the tube side. Near the flue gas outlet, the temperature of the high-temperature flue gas decreases after heat exchange. In the tube at the corresponding position is the low-temperature medium that has just flowed into the heat exchanger, resulting in a low wall temperature o...

AI Technical Summary

Problems solved by technology

However, taking the practical application of heat exchange between acidic high-temperature flue gas and low-temperature medium as an example, the acidic high-temperature flue gas goes through the shell side, and the low-temperature medium goes through the tube side. Near the flue gas outlet, the temperature of the high-temperature flue gas decreases after heat exchange. In the tube at the corresponding position is the low-temperature medium that has just flowed into the heat exchanger, resulting in a low wall temperature of the heat exchange tube at the outlet of the flue gas

Because the acidic high-temperature flue gas contains acidic and corrosive gas components, such as sulfur dioxide, when the temperature is lower than its acid dew point corrosion temperature, it will corrode the metal heat exchange tubes, causing some heat exchange tubes to corrode, perforate and leak, affecting the heat exchange rate. The heat exchange effect and service life of the heater, but if the exhaust gas temperature is increased to avoid dew point corrosion, it will cause waste of high-temperature flue gas waste heat

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