关键词: 常压塔, 抽出位置, 取热量, 换热网络, 换热终温

Abstract: Taking the atmospheric tower of a ten million ton refinery as the research object, the influence of extraction position of the middle section of the atmospheric tower on the heat exchange network is investigated by using PRO Ⅱ process simulation software and i-HEAT heat exchange network calculation software. The results show that when the second middle extraction/return position of atmospheric tower moves down to the same position of the third side line. The temperature of heat extraction can be increased by 12 ℃, the heat extraction can be increased by 9.3 MW, the final temperature of heat exchange by the economic pinch temperature difference can be increased by 1.2 ℃, the heat load of the heating furnace and cooling water consumption are reduced by 0.9 MW and 0.5 MW respectively. The temperature of the surplus heat below the pinch point increases correspondingly. The original surplus heat can produce 11.7 MW medium-pressure steam and 4.4 MW low temperature hot water. After the scheme adjustment, the surplus heat can produce 10.6 MW high-pressure steam and 5.6 MW medium-pressure steam. The steam output and pressure increase obviously and the economic benefit is remarkable. Especially for refineries with insufficient high-pressure steam, moving down second middle extraction/return position of atmospheric tower represents a significant advantage.

Key words: atmospheric tower, extraction position, heat extraction, heat exchanger network, final temperature of heat exchange