Home » Temperature Controller Problem
Control Systems Temperature Measurement

Temperature Controller Problem

Suppose a chemical reactor is heated by steam. A temperature controller varies the amount of steam admitted to a “jacket” surrounding the reactor:

Temperature Controller Problem

Temperature Controller Problem

Ever since this process was placed into service, operators have complained about poor temperature control. Several technicians have tried to tune the PID controller, but no combination of tuning constants seems to solve the problem of random reactor temperature fluctuations.

Then one day you notice that the “random” fluctuations of temperature are not really random at all: they directly follow fluctuations in steam supply pressure over time.

Explain the nature of the control problem (why do variations in steam supply pressure affect the reactor temperature?), and propose a solution for it.

Answer:

As the steam supply pressure rises and falls, a greater or lesser steam flow will result through the temperature valve (TV) for any given stem position.

The simplest and most direct solution to this problem is to stabilize the steam supply pressure: determine what is causing the pressure to fluctuate, and fix it!

Question for you:

Like so many real-life problems, there are usually multiple solutions. Try brainstorming more than one practical solution to this control problem! (assume possible cases).

Join the Discussion! Share your answers with us through below comments section.

Read Next:

Share With Your Friends

Related Articles

What is Energy Monitoring System ?

S Bharadwaj Reddy

What is the OPC Server?

S Bharadwaj Reddy

What is a Control Loop ?

S Bharadwaj Reddy

Identify Faults in PID Control Loop

S Bharadwaj Reddy

PID Controllers with Output High Select Logic

S Bharadwaj Reddy

3 comments

Andre March 3, 2020 at 1:40 am

If you weren’t able to stabilize the steam pressure supply, perhaps you could instead create logic that reacts to a steam pressure transmitter that correspondingly adjusts the TV to adjust for it.

Thanks for posting these thought experiments by the way! I’m a new intern working in process control and just found this website. Really nice resource.

Reply
keciri March 29, 2020 at 6:57 pm

salut. je tient a vous remerci pour ses infos ,car tous ce que je reherche je le trouve sur ce site avec des resumer bien expliquer. merci encors une et bon continuation.

Translated from french:

Hi. I want to thank you for this info because all that I am looking for, I find on this site with summaries, explained well. thanks again and good luck

Reply
Tk April 7, 2020 at 11:13 pm

Add a flow meter and use cascade control requires capital
If you have header pressure try to add a feedforward signal to the TC

Reply

Leave a Comment

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More

Temperature Controller Problem

WordPress Image Lightbox
Send this to a friend