Refrigeration Piping Calculation

[Kevin Yeo]

Hi all,

As energy cost escalates, customers are very cautious about what type of system and piping they are getting from contractors. Very often, the question of how much is your design pressure drops is being asked.
I normally size the pipes based on charts and hence have problem getting pressure drops in numerical value. I understand there are softwares out there, such as Mistral pipewind. May I know any one has used this software and is it effective and accurate to calculate the pressure drops, mass flow and velocity with regards to SST, pipe distance (both vertical and horizontal), and expansion valves sizing.

Thanks a lot and have a nice day.

rgds,
Kevin

[750 Valve]

I use either Danfoss DIRcalac downloadable here - http://www.danfoss.com/North_America...ls/DIRcalc.htm

or the Sporlan program downloadable here - http://www.parker.com/portal/site/PA...extfmt=default

you need to fill out a survey for the sporlan one but I don't think you need to register, they just take your details

[D.D.KORANNE]

You can use solken program for pipe size calculations, mass flow & other data for ref system .

[Kevin Yeo]

thanks to all

[FreezerGeezer]

Great links 750, thanks a lot!

[Y L Lai]

Newer version coming up soon to replace DirCal. Visit Danfoss website to find out more.

[suki35]

We have been using Mistral software for pipesizing and all other refrigeration engineering for the past twelve years and found it to be totally reliable. It also has to be the easiest and fastest software we've ever used. Look at mistralassociates.com

[Peter_1]

I'm using - in fact I used it - also Mistral and lots of features are calculating the wrong way and/or important features aren't included.
Some examples (not lilited)
1)how do you calculate pressure drop in the lines with Mistral and how do you downsize lines just till you have not too much speed but falls safely within the 1K rule?
2) What about different sections in 1 line (smaller sections for risers)
3) You can't add a subcooling of let's say 20K, 10K is max.
4) You give in fix load and the software gives you a max and a min speed. How's that possible for a fix load?
5) You can't choose R410a nor R507c, no NH3, no blends like R401a, R408,...
.....

These are only some comments about line sizing.

It's a fancy looking program, :-(