Heat Transfer: Plate Heating with Water Tube

performance analysis for plate heat exchanger with various chevron ...

Heat Transfer Analysis of Corrugated Plate Heat Exchanger of ...

I haven't looked at these. That's your assignment.

As you should have noticed Cr4 makes CORRECTION comments on presented solutions.

I would suggest you proceed first AS YOU THINK and describe the way of your thoughts and then I will give you ALL hints you need if your choice is wrong or congratulate if the choice is right.

By the way in the most simple book about heat transfer you find ALL what you need to solve your problem and be proud to have done on yourself!

I've presented a simplified form of the problem, and have maybe given the impression that this is some sort of student excercise. Some background:

1. The plate shown is a large vacuum vessel barrier, with vacuum being on the "Twall" side. Plate dimensions are 2m (L) x 1m (W) x .100m (TH).

2. The tube is actually a serpentine routing over the face of the plate and must provide enough heat to maintain Twall = 200C for vacuum bakeout. So there is more plate and more tube than shown. Tube is presently 14mm OD and 10mm ID. Supply water temp is 240C.

3. The problem is to design adequate hot water flow to maintain the 200C temp on the vacuum wall.

4. I imagine this problem will need to be considered as transient, with P and mass flow considerations,etc, but I hope to just tackle steady state for now.

Though not a thermal designer, I do have a stack of heat transfer books on my desk (including the Lienhardt volume) but the appropriate example has not yet leapt from the pages. Unfortunately, I am not being paid to study texts all day. I am reaching out to the CR4 communty for some assistance with initial assumptions. Before punting this to a CFD/thermal analyst for modeling, I would like to perform a simplified hand calc for comparison and I would like to post a more developed solution here.

I've used "convection through a hollow cylinder" examples to calculate q released by the water tube, but how to analyze conduction from the tube, across the plate? Typical conduction across wall problems seem to use a constant wall temp on the heat source side.

1-In vacuum heat is transferred ONLY by radiation flux being variable depending on the body temperature. If the container would be full of air or any other gas then convection would be predominant.

2-From tube to wall heat is transferred by conduction over the contact zones and those depend on the way tube and wall are fastened together.

3-Your system is -as presented - not insulated with respect to environment the wall temperature depends on the TOTAL heat balance.

4-You are paid to solve a problem and if you cannot solve it you do not deserve your pay.

5-I was also confronted with such situations since nobody knows ALL but usually when I did not have time during the day to read the books which helped me to solve the problems I did it during evenings or even at night if the problem was stringent and urgent. This the investment you have to do to reach the expected level and justify you wages!

6-We are not payed you are the one then make the effort.

7- If you have Lienhardt (a book where every thing is explained in a very understandable form) and you cannot solve the problem -which is very simple- this means you only kept it on the shelf and did not look at the content.

Pompous judgemental crap from a frustrated schoolmaster posing on an engineering forum. You are in no position to assess my work performance, circumstances or efforts I expend on my own time. Thanks for sharing, "Guru".

Your reaction shows that you are almost mad at what I wrote.

It is know that only truth disturbs. In fact you know that I am right but you have not the courage to recognize it! Insulting is not the reaction of a civilized person.

To your information I am not a schoolmaster as you presume but an engineer with MANY tenth of years of experience in design and manufacturing in several fields and I am NOT at all frustrated I had and have a full professional life with many satisfactions since I am consulted by many companies to solve difficult problems.

By the way I gave you a lot of hints to solve your problem if in stead of keeping the books on the shelf you try to read and UNDERSTAND them. With what I wrote you can do all what you need! Of course under previous preparation. It is not necessary to make a computer FEA simulation all can be done by hand and may be a spread sheet but only if you understand how the transfer occurs what you did not till last message.

http://www.amazon.co.uk/Fundamentals-Momentum-Heat-Mass-Transfer/dp/0471381497

There is very good book to download free

"A heat transfert book" John H. Lienhardt Father(IV) and son (V). 4th edition.