Three-flow low-temperature coiling tubular heat exchanger for feed gas cooler

Abstract

The invention provides a three-flow low-temperature coiling tubular heat exchanger for a feed gas cooler. The three-flow low-temperature coiling tubular heat exchanger is mainly applied to the field of coal chemical industries such as coal gasification and coal-to-methanol, and is independent tube bundle type three-flow spiral coiling tubular heat exchange equipment which is formed by sequentially coiling three-flow tube bundles in layers. According to the three-flow low-temperature coiling tubular heat exchanger for the feed gas cooler, three cold source tube bundles, namely, a tube side tail gas tube bundle, a tube side CO2 tube bundle and a tube side synthetic gas tube bundle are adopted and used for pre-cooling shell side feed gas, and are sequentially inserted into an intermediate-temperature cold source through a middle section; a three-flow heat exchange area, a two-flow heat exchange area and a single-flow heat exchange area are distributed in an overlapping manner; and the whole heat exchanger is a three-flow spiral coiling tubular heat exchanger with a tower structure and meets the technical requirement of the feed gas cooler on pre-cooling the feed gas through the after-cold generated in a three-flow system technology. The heat exchanger has the characteristics of being compact in structure and large in heat exchange area per unit volume, and can realize multi-flow heat exchange; a heat transfer pipe under heat expansion can be automatically compensated, so that large scale is easily realized, and the amount of technological heat exchange equipment can be reduced; and the heat exchanger for the conventional single-flow feed gas cooler can be replaced by the three-flow low-temperature coiling tubular heat exchanger provided by the invention.

Description

technical field [0001] The invention relates to a three-stream low-temperature winding tube heat exchanger for a raw material gas cooler, which is mainly used in the fields of coal chemical industry such as coal-to-gas and coal-to-methanol, including the technical fields of gas low-temperature purification and low-temperature liquefaction separation such as -70°C low-temperature methanol process. According to different import and export media and parameters, it can also be used in natural gas liquefaction, air liquefaction separation, low-temperature liquid nitrogen washing and other multi-stream heat exchange and other fields. Background technique [0002] The three-flow low-temperature winding tube heat exchanger for raw material gas cooler is a three-flow spiral coil heat exchange equipment formed by winding heat exchange pipes layer by layer. , Tube side -37°C carbon dioxide, tube side -21.24°C synthetic gas cooling shell side 40°C raw material gas, so that the temperatu...

AI Technical Summary

Problems solved by technology

First of all, the traditional raw material gas uses three independent single-flow shell and tube heat exchangers for pre-cooling and heat exchange. The heat exchanger has a large volume, a small heat exchange area per unit volume, and a low heat exchange efficiency.

Secondly, since the temperatures of the three cold sources in the heat exchange temperature zone of the feed gas cooler are -51.3°C, -37°C and -21.24°C respectively, during the process of cooling the raw material at 40°C, due to the large temperature difference between the three cold streams , if the traditional three-stream heat exchanger is used, the -21.24°C synthesis gas cooling source at the tube side inlet and the -37°C carbon dioxide will absorb the cooling capacity of the -51.3°C exhaust gas cooling source. After the temperature drops, they will jointly cool the shell side by 40°C When the raw material gas reaches -17°C, that is, syngas at -21.24°C, carbon dioxide at -37°C, and tail gas at -51.3°C will exchange heat with each other. Repeated heat exchange between sources reduces heat exchange efficiency and increases heat exchange area

Furthermore, since the existing multi-stream wound tube heat exchangers are mainly used in low-temperature environments, the internal multi-stream tube bundles are intertwined, and the heat transfer process is complicated. There is no general design standard, and there is no unified design calculation method. There are large differences with the process flow or physical parameters, so it brings obstacles to the design and development of three-stream low-temperature wound tube heat exchangers for feed gas coolers

Finally, since the raw material gas cooler uses three streams of low-temperature winding tube heat exchangers, there are many ways to wind the coiled tube bundles, and there is no unified pipe winding mode and theoretical design calculation method for the computer-aided calculation process. Three streams are used for the raw gas cooler Scientific calculation and standardization of low temperature coiled tube heat exchangers present obstacles

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