1. La la la, I’m hungry! What shall I eat today?

2. Meanwhile……….

3. It wasn’t my fault, the magnesium plant was sabotaged! The gasification reactor data was bad, I didn’t have anything to do with it! It was a ChE 230 student! The glove didn’t even fit!

4. Ow jeeze hot! How will I cool this down….

5. I know….a counter-current heat exchanger!

6. But how much cooling will I need, and how will I control it? What a coincidence! There’s an excel model with the exact same fluid properties as my human soup! (Optimizing Heat Exchanger)

7. This soup is boiling at 330K! Everyone knows human soup is cooked and served best at 274K!!! It’s really very simple now that we have a model! We just need to optimize the heat exchanger so my soup is always 274K!

8. Let’s take a look at the system and see how we can optimize it! I KNOW! Minimize the error!!!!! But how do we get the error… Hrm…

9. We want to minimize this error. We have to subtract the set point temperature (SP) from the temperature of the soup exiting the heat exchanger (TH3). Then we square the error.

10. Let’s open the solver function in excel. WHAT THE JUNK DOES THIS DO???? Oh, I get it. We set the target cell as the summed error, because that’s what we want to minimize. Then we click minimize in the “equal to” section.

11. Now, we have to select the cells to modify by putting them in the “by changing the cells” box. For this example, we want to modify K c, T i and T d which are coefficients of the tuning equation. (They are off to the right in yellow in the excel sheet).

12. Would you look at that! If we graph the soup temperature as it exits the heat exchanger, we see that it stays around 274K.

13. Mmmm, I finally get to enjoy my human soup! Guess that degree in chemical engineering was useful after all!