利用炼化企业低温余热的低温多效蒸馏海水淡化技术

Low-temperature multi-effect evaporation seawater desalination process using low-temperature waste heat of refinery enterprises

简要介绍了炼化企业的低温余热回收利用现状,阐述了目前低温多效蒸馏海水淡化技术（LT-MED）的发展水平、技术特点和发展趋势.以某沿海石化企业为例,对利用低温余热LT-MED技术的技术方案和成本进行了分析,得出的结论是：炼化企业低温余热回收系统的回收热水温度一般为95～100℃,取热温度为65～70℃,与MED技术的运行参数较为吻合；用MED技术生产的一级除盐水价格一般在4～6元/m3,而沿海炼化企业的一级除盐水的价格普遍高于7元/m3,视全厂所需的除盐水量适时进行建设,应该可以取得较好的收益.

This paper introduces the status quo of low-temperature waste heat utilization of refineries and the development, technical features and developing trend of low-temperature multi-effect evaporation seawater desalination （LT-MED） process. In a case study of a refinery, the scheme and economy of LT-MED technolo- gy for the utilization of waste heat are analyzed and studied. It is concluded that the recovery water temperature in the low-temperature waste heat recovery system of petrochemical company is generally 95 - 100 ℃ and the heat temperature is generally 65 -70 ℃, which meet the operation requirements of MED; The cost of primary desahed water produced by MED technology is generally 4 ～ 6 Yuan/m3, and the price of the refinery primary desahed water is generally higher than the 7 Yuan/m3. The construction of MED system based on the desahed water demand will have a good benefit.