案例6：加氢脱硫（HDS）和进料混合控制-3
作为一个实际问题，运行SMOCPro控制器时需要关注怎么最小化双线性经济函数，因为这能增加效益。
根据下列参数创建一个仿真场景（最大化Feed）：
常规选项
Blend HDS 选项
HDS Reactor选项
使用不同的变量列表运行仿真，以分析控制器性能。
Blend HDS 变量列表图
Reactor HDS变量列表图
SMOCPro通过最小化Density（密度），最大化SULPHUR和最大化温度限制来达到最大化Feed。它通过使用Kero最小化SULPHUR IN，从而最小化Density（密度）限。
我们现在来测试一个接近于最大化HDS利润率的经济函数。实施以下经济函数。
Max Profit （最大利润）= [GO value – (price of the Feed)]
在本例中GO的数是Feed流股自身。打开控制器的Economic Function窗口，并将此函数定义为最大化利润。注意在SMOCPro最小化经济函数时，因此在不同的进料（AGO）成本前确定积极和消极的因素时，需要采取特别的预防措施。
编译更新后的控制器，并按照下面的步骤来构建一个稍微复杂的模拟场景。
General选项
在第1步时启动Max Profit（最大化利润）函数，并在第60步时切换到Max Feed（最大进料）函数。
Blend HDS选项
在第35步时，提高HGO的可用范围。
运行此仿真。
Blend HDS变量列表
在第35步时SMOCPro使用更多的HGO触碰Density高限。在第60步时，由于新价格的差异SMOCPro最小化Kero。然后其最大化Kero以减少SULPHUR IN并最大化Feed。
Reactor HDS变量列表
SMOCPro推动Feed将炉的TRC驱动到高限。当处于最大Feed情况且SULPHUR IN在减少时，其增大Feed。
带回家的消息
该子系统主体工具在提升用户管理GMB模型方面非常有用。
通过在SMOCPro相应的子控制器概要选项卡中选择“Blending Subcontroller”标签，混合子控制器可以很容易地被搭建。需要记住的重要一点是，这些子控制器没有动态轨迹，且只作用于稳态值。此外，这些子控制器还有附加约束，即MVs和DVs的和必须等于1。
我们可以在控制器节点的Economic Functions部分创建线性，二次和双线性经济函数。用户也可以通过离线仿真或HMI在线系统修改经济函数的经济系数。此功能可用于在线修改控制器行为，而不必输出应用到离线，重建并向在线系统重新导入控制器。
原文：
As a practical point, see how minimizing bilinear economic functions can increase the benefit of running the SMOCPro controller.
Create a simulation scenario (Max Feed) with the following parameters:
General tab
Blend HDS tab
HDS Reactor tab
Run the simulation while using different Variable Lists to analyze the controller performance.
Blend HDS Variable List plot
Reactor HDS Variable List plot
SMOCPro maximizes the Feed up to the minimum Density, maximum SULPHUR and maximum Temperature limits. It has used Kero to minimize the SULPHUR IN up to the minimum Density limit.
We now turn to test an economic function that is somewhat closer to maximizing the HDS margin. Implement the following economic function.
****Max Profit = [GO value – (price of the Feed)]****
In this example the quantity of GO is the Feed flow itself. Open the controller’s Economic Function window and define this function as Max Profit. Remember that SMOCPro minimizes the economic function, therefore take special precautions when defining the positive and negative factors in front of the different Feed (AGO) costs.
Compile the updated controller and following the next steps to build a slightly more complex simulation scenario.
General tab
Start with the Max Profit function at step 1 and at step 60 switch to the Max Feed function.
Blend HDS tab
At step 35, there is more HGO available.
Run the simulation.
Blend HDS Variable List
SMOCPro uses more HGO at step 35 up to the high Density limit. At step 60, SMOCPro minimizes the Kero because of the new price differential. Then it maximizes Kero to reduce the SULPHUR IN and maximize the Feed.
Reactor HDS Variable List
SMOCPro pushes the Feed up to the furnace TRC high limit. It increases the Feed when the SULPHUR IN is reduced in the Max Feed case.
Take Home Message
The subsystem entity is a tool that is useful in providing the users the ability to better manage models in GMB.
Blending sub-controllers can easily be constructed in SMOCPro by selecting the “Blending Subcontroller” flag in the appropriate sub-controller summary tab. It is important to remember that these sub-controllers have no dynamic trajectories and are only acting on steady state values. In addition, these sub-controllers have the additional constraint that the sum of MVs and DVs must equal 1.
Linear, quadratic and bilinear economic fuctions can created in the Economic Functions section of the Controller node. The user also has the ability to modify the Economic Coefficients defined for the Economic Functions via offline simulations and on the online system from the HMI. This feature can be used to modify the behavior of the controller on the fly without having to export the application offline, rebuild and reimport the controller to the online system.
2016.6.11
