Search results

I am looking at the external pipe heat transfer.   With an 80F external wall pipe temperature in a space that is somewhat colder that -320F.   There should be an increased transfer rate above that of the radiant heat transfer: (a) natural convection - Assuming no velocity is induced from the...

I just think problem needs to state, neglect the convective heat transfer...    

So we were to ignore the convective heat transfer portion of the problem?  The flashing of the Nitrogen should have induced a velocity in the chamber and enhanced the heat transfer.  Similar to example 37.1 in MERM...  On page 37-4 thru 37-6.

I would like to see the solution for this...   I must be making this more difficult than what it is.

I used 71F for the Tdp...  I got 9.3F.   But when I substitute in 70.2F I get -3.8F  Pretty large swing.  All answers were possible in this problem

Slay, I tried this...   However I converted the straight pipe, for each branch, into a K and summed all the K's for each branch.  Plugged into the Bernoulli equation.  And Came up with something in the area of (B). But, in the TFS the answer was reported as (D).  In the solution posted in the...

I got something less than (D)

I tried this too,  and I am not getting it, either.

Nice! I am envious of your knowledge and penmanship. 

OOF!!!   I can not remember how to approach these problems...  Partial Credit Given?

Welcome Vitalvi... 

I would actually recommend using the ASHRAE Chart, as that is what you will see on the exam.

Two air streams are mixed: (A) is 5000 ft^3/min @ 40Fdb/35Fwb (B) is 15000 ft^3/min @ 75Fdb/50% rh Find the mixed dry bulb temperature. The specific volume for stream B @ 75Fdb/50%rh = ~ 13.7 ft^3/lbm  Try using the psych chart in the MERM 13  Appendix A-137 it has 0.1 graduations for...

I highly suggest you take the Slay the PE for the TFS material.  There is/was a a great deal of TFS material on the HVAC & R exam.  It is great source material and if you act quickly  you can get 50% off the material by doing the contest. Contest PS...   Most people consider the 6 minute...

Sent... PS...  I have crappy lead in my pencil and it's sloppy..

The drag files here to attach is not there for me in PM.....

How do you upload the scanned document in PM?

I am one of those people that work through the problems in order.  I have tried the skip through and answer the problems but I always screw up putting the answer down on the scan tron sheet.  I quit doing that method long ago.   If you can do it without screwing up...   Kudos to you.   

Should only be in imperial... 

Canada... https://www.amazon.ca/Six-Minute-Solutions-Mechanical-Refrigeration-Problems/dp/1591260132