关键词: 芳烃联合装置, 低温余热利用, 抽余液塔, 抽出液塔, 蒸汽发电, 蒸汽升压, 空气冷却器

Abstract:

Taking the utilization of low temperature heat at the top of the raffinate tower and extract tower in an aromatics plant as an example, the design principles for heat extraction, as well as the operating conditions and processes for generating steam from low temperature heat at the top of the tower, are proposed. Detailed analysis and calculation are conducted on the two utilization schemes of steam boosting and steam power generation, and optimized design schemes are obtained. When using the steam boosting scheme, it is advisable to use a screw compressor for boosting. When using the steam power generation scheme, it is recommended to use an air cooler to cool the condensed steam when the land occupation allows. The environmental temperature has a significant impact on the net power generation, so it is recommended to use an air cooler design temperature for design. For the selection of steam boosting and power generation schemes, boosting steam should prioritize replacing steam obtained from higher grade steam decompression, and the scheme has the best benefits at this time; if there are no alternative users, it is recommended to use steam power generation scheme when the electricity price is higher than 0.54 yuan/(kW·h).

Key words: aromatics complex, low temperature waste heat utilization, raffinate tower, extract tower, steam power, steam boosting, air cooler