3 replies to this topic

[abolghasem202]

Dear all,

 

I have a problem in thermal rating of a shell and tube heat exchanger using HTRI V7.3. I would appreciate your kind suggestions on my problem.

 

This exchanger is going to be used for utilizing steam at about P= 44bar and T>400C for heating a process stream from 34C to 232C. 

 

I have run this exchanger in two cases:

Case 1: Inlet steam temperature = 410C.

Case 2: Inlet steam temperature = 415C.

 

Cold side properties and exchanger geometry are the same for the two cases. The only difference is inlet steam temperature.

 

Im not expecting to have a significant difference in obtained results for the two cases, e.g. overdesign percent. But HTRI results are so different for the two cases. Some of the HTRI results are:

 

Case 1: Overall heat transfer coefficient = 469kcal/m2-hr-C, Overdesign=51.39%.

Case 2: Overall heat transfer coefficient = 329kcal/m2-hr-C, Overdesign=3.6%.

 

Does it really make that much difference to have a steam temperature of 410 and 415C?

 

Rating results of HTRI for the cases are attached.

 

Awaiting your kind responses.

 

 Case1.jpg   149.48KB   8 downloads

 Case 2.jpg   151.55KB   5 downloads

[Pilesar]

The number of baffles is different between the two cases.

[abolghasem202]

Thanks for the reply.

 

However, but in my attached images, the baffle spacing and tube length are the same for the two cases. So, I would expect the same number of baffles. 

[Pilesar]

Case 1 has twice the number of baffles of Case 2 despite your expectations. Count them.