Low-temperature spiral wound heat exchanger for non-converted gas cooler

Abstract

The invention discloses a low-temperature spiral wound heat exchanger for a non-converted gas cooler, and is mainly applied to the coal chemical industry fields of coal based syngas, coal-to-methanol, and the like, and the technical fields of the rectisol process comprising low-temperature gas purification and low-temperature liquefaction separation, and the like. The low-temperature spiral wound heat exchanger is tower spiral wound heat exchange equipment with the combination of single-fluid and double-fluid, achieving the purpose of precooling non-converted feed gas by process cold gas by mainly utilizing rectisol process off-gas and low-temperature syngas to precool the non-converted feed gas. According to the low-temperature spiral wound heat exchanger for the non-converted gas cooler, disclosed by the invention, the basic structure and the heat exchange process calculation method of a compound spiral wound heat exchanger combining a single-tube-bundle spiral wound heat exchanger and a double-tube-bundle spiral wound heat exchanger for the non-converted gas cooler are systematically researched, the method of introducing the moderate temperature cold source at the middle section and combining the single-fluid and double-fluid spiral wound heat exchangers up and down is adopted, and the entry points of multi-fluid heat exchange at different potential temperatures are improved, so that the heat exchange efficiency is enhanced, the heat exchange area is saved, and the size of the heat exchanger is reduced.

Description

technical field [0001] The invention relates to a low-temperature winding tube heat exchanger for an unconverted gas 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 low-temperature wound tube heat exchanger for the unconverted gas cooler is a spiral coil heat exchange device that combines a single tube bundle and a double tube bundle formed by winding the heat exchange pipe layer by layer. It mainly uses two cold sources, namely The tail gas at -51.3°C in the tube pass and the syngas at -18.39°C in the tube pass cool the unconverted gas at 37.73°C in the shell side, reducing its temperature to -10.09°C, and the temperature of the two tube pass gases rises to 31.23°C. The main component of unconverted gas is water...

AI Technical Summary

Problems solved by technology

First of all, the traditional unconverted gas cooler adopts two independent single-flow shell-and-tube heat exchangers for heat exchange. The heat exchanger has a large volume, a small heat exchange area per unit volume, and low heat exchange efficiency.

Secondly, since the temperatures of the two cold streams in the heat exchange temperature zone of the unshifted gas cooler are -51.3°C and -18.39°C respectively, in the process of cooling the feed gas at 37.73°C, due to the large temperature difference between the two cold streams , if the double-stream heat exchanger is used alone, the -18.39°C synthesis gas at the inlet of the tube side will absorb the cooling capacity of the -51.3°C tail gas. When it drops to -10.09°C, that is, the synthesis gas at -18.39°C will experience a process of first cooling down and then heating up, resulting in an increase in the heat transfer area and a decrease in heat transfer efficiency

Furthermore, since the coiled tube heat exchanger is used in a low-temperature environment, the internal heat transfer process is complicated, there is no general design standard, and there is no unified design calculation method, and there are large differences with different technological processes or physical parameters, so , which brings obstacles to the design and development of low temperature wound tube heat exchangers for unshifted gas coolers

Finally, since there are many methods of intertwining the coiled tube bundles in the low-temperature wound tube heat exchanger for the unshifted gas cooler, there is no unified pipe winding mode and theoretical design calculation method for the computer-aided calculation process. Scientific calculations and standardization of wound tube heat exchangers present obstacles

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