You can find these mathematical models in Heat and Mass Transfer books, like: "Fundamentals of Heat and Mass Transfer" from Theodore L. Bergman, Adrienne S. Lavine, Frank P. Incropera, David P. DeWitt. I have the link for the full textbook. If you want it, send me a private message. Best regards, prof. Strobel.

Dear Nishtha,

Whatever Prof. Strobel mentioned can be useful for understanding the basics, Moreover, I suggest you to survey the industrial existed preheater (maybe cataloges or websites), and getting their parameters and some effort of re-engineering may save you some time, If you are going for designing and fabrication, and even simulation!

Sincerely,

Azd.

Kays and London, Compact Heat Exchangers

This is the best reference book for compact heat exchanger design according to my personal experience.

You can't do better than Google "rotary regenerative heat exchanger design".

This way, you will get much better information.

Also try

"www.freefullpdf.com"

This is a very good source.