the reflux drum (reboiler) as far as the composition
of the liquid in the product tank satisfies the product
specification. Finally, the slop cut is withdrawn until
the composition of the liquid in the reboiler (reflux
drum) satisfies the heaviest (lightest) product
specification.
Total reflux column: first, the reboiler, the reflux
drum and all trays are filled with raw material at a
boiling temperature. Then, the lightest product is
accumulated in the reflux drum under the total reflux
operation. After the total reflux operation, the entire
product in the reflux drum is withdrawn to the
product tank instantaneously and some amount ofmaterial in the reboiler is transferred to the reflux
drum immediately. Next, the slop cut is accumulated
in the reflux drum, then withdrawn to the slop cut
tank. The amount of the slop cut is also regarded as
an optimization variable. Similar operation is re-
peated for accumulating and withdrawing the inter-
mediate product and the second slop cut.
The column data used in this paper are given in
Table 1. In order to compare all batch distillation
columns, the number of stages and the amount of feed
are assumed to be the same for all columns. The 13
different separation problems, which are shown in
Table 2, are solved for the following two types of
operation policies:
Constant reflux policy (C-policy) : the reflux flow rates
during the product and the slop cut separations are
constant, and all of the reflux rates are optimized so
as to maximize P.I. In case of the C-policy of a
rectifying column and a stripping column, the total
reflux operation is inserted before the lightest
product withdrawal until the composition of the liq-
uid in the reflux drum satisfies the lightest product
specification.
Variable reflux policy (V-policy) : the reflux flow rate
during the entire operation period is optimized as a
function of time. In case of ternary separation by a rectifying column,
the total distillation time is pided into four time
periods shown in Fig. 2. From time 0 to t1, the lightest
product P1 is withdrawn to the product tank. Also
during successive time periods, S1, P2 and S2 are
withdrawn. At the end of these time periods, the con-
straints on product compositions, as shown below,
must be satisfied. There is no constraint on the termina-
tion of the second period. In the cases of the C-policy
of a rectifying column and a stripping column, the first
time period is further pided into two sub-periods: the
total reflux operation period and the product with-
drawal period.
t1: Composition of P1]Product specification for P1.摘要:最优的结构和操作一批蒸馏柱分离三元混合物从节能的角度讨论。最优回流操作,最大限度地减少能源消耗，推导出三种类型的批处理蒸馏塔：整流、剥离和全回列。分离性能测量方面的能源消耗在不同条件下计算出每一列。例子的结果总回流的问题表明分离性能的回流列可以大大提高了优化回流流量,而那些的整流和剥离列不能。实验证实使用一个试验工厂的能源消耗总额可以大大少于回流列优化运行时使用的总额。
关键词:分批蒸馏柱、最优结构、在线优化、试验工厂。 蒸馏塔英文文献和中文翻译(3):http://www.751com.cn/fanyi/lunwen_12290.html