化工系统节能“瓶颈”的辨识及解“瓶颈”

Identifying and relaxing energy bottleneck for a chemical system

化工系统的复杂性决定了要对其进行节能优化需要找到系统的“瓶颈”,换热网络的瓶颈通常在夹点处,但在某些情况下,夹点已不再是系统的瓶颈所在,其他设备的工艺条件也会成为化工系统的瓶颈,决定整个系统的节能潜力。文中提出通过费用曲线来辩识系统瓶颈,该曲线上斜率突然增大并使得节能改造的投资回收期大于期望值处,代表了系统节能的瓶颈。分析瓶颈形成的原因,并考虑消除或减缓该原因的措施,就可以实现解瓶颈,从而使系统在较少的投资下获得较大的节能效益。最后通过实例说明如何辩识瓶颈和解瓶颈。

It is very important to identify the energy bottleneck for a complex chemical system so as to maximize the energy-saving benefit of the system. The bottleneck of a heat exchanger network is usually at the pinch point. However, in some cases, instead of the pinch point, the operation condition of other equipment becomes the energy bottleneck of a chemical system, which controls the energy-saving potential of the system. To propose that the energy bottleneck for a complex chemical system can be identified by using the cost curve. The bottleneck of a system is located at the point where the curve becomes steeper. By analyzing and eliminating the reason how the bottleneck is formed, the bottleneck can be relaxed. A case study is used to illustrate how to identify and relax the bottleneck.