Refrigeration System Equilibrium

[Mobbsy]

I was hoping someone may be able to help me. I have been searching high and low for software which calculates the balance point and evaluates the operating performance for any particular combination of evaporator, compressor and condenser.
I have an appreciation for the old school method of plotting the points and creating a graphical representation, but I was hoping to acquire some software.

[GXMPLX]

Me too! If you find a good one mail me!

In general specialized software is really expensive or not available outside a closed circle.

But you can use EES (Engineering Equation Solver) is the least expensive and comes with many handy books but the real advantage is that it already has refrigerant tables and recent versions even functions for nucleate boiling heat transfer film coefficients.
www.fchart.com

I think the best one is Mathematica, but it is expensive and probably much more than you need to handle. Another problem is you have to buy NIST RefProp and call it’s functions from an external DLL.

Maybe Mathematica CalcCenter3 is less expensive but you cannot call the external functions but can use interpolation tables with refrigerant properties, also the graph possibilities are limited but can also solve all your refrigeration problems and much more.


You get them both from www.wolfram.com

Also expensive, I like it less because the language is a little awkward but a VERY good tool, does need NIST RefProp is MatLab www.mathworks.com this together with Simulink are the programs used in the navy … Shhhhh (don’t say which navy)!


These are all general purpose will let you solve any problem with ample graph capability but you do get other specialized to simulate fluid flow in pipes, dynamic systems but have less scope.

If you are a student you can get a licence at bargain price from each of them!

[Peter_1]

Well GXMPLX, speaking of coincidence, what have I said in a post of yesterday or the day before? Software, software...
Mobbsy, the fact that you know the classic method means you already used and understood how this works.
I think it will difficult to make software for this because the programmer can't put all the variables of the different components from different manufacturers in a database.
Because that's what you will need.

You can input some variables in Excel and make an iteration on it (don't know the correct English expression for it, it's try something and see if the result matches what you want and increase or decrease your values till you get the desired value, Excel has a special function for this)

But,...we had a very clever Chinese member some time ago and he made software for this problem.He send me once a copy of it but I'm not allowed to share this without his permission. Even then, I don't know where to look for the moment.
The software called Flying Carpet or something like that.

[Josip]

Hi, Mobbsy

.... sorry no hope .... now ... ,but one day...maybe

I was hoping someone may be able to help me. I have been searching high and low for software which calculates the balance point and evaluates the operating performance for any particular combination of evaporator, compressor and condenser.
I have an appreciation for the old school method of plotting the points and creating a graphical representation, but I was hoping to acquire some software.

.... that kind of software you can (maybe!?) get from Frick - Coolware, Sabroe- MatchMaster, and some other, but they strictly cover their own products ... i.e. it is not possible to calculate different products ...

.... but you have similar software for refrigerant pumps, evaporators, condensers, valves, pipe loss calculations, insulation .... and then again put all together .... manually

Best regards, Josip

[Mobbsy]

Thankyou all very much for your quick responses. Looks like I'm on a mission to create something of my own. What Peter suggests with excel is correct, I have already played around with the concept of using excel. Josips suggestion that manufacturers have their own software, specific for particular brands is also correct, because I have seen some of them, but at this stage have been unable to procure any. If the Chinese member is willing to share Flying carpet for a nominal amount he/she would be providing a great service to the industry. I feel it would promote a greater awareness within the industry of system equilibrium and the effects on particular system operating characteristics under varying conditions. This could also lead to a better understanding of floating head pressures e.t.c in an ever increasing energy conscious world. If I find something GMPLX I will let you know and thankyou very much for the links.

[GXMPLX]

Excel is a good tool too but must be used with NIST RefProp to be of good use in refrigeration. With this you'll be able to solve almost anything, but the graphs are much better in any of the ones I mentioned.

EES and MatLab interact closely with Excel.

You can get compressor coefficients from several manufacturers to model compressors with cuadratic forms as mentioned in standard ARI 540.

Don't give up! In the future you'll build first a virtual system then as US_Iceman likes to say it will "magically" be built!

[Mobbsy]

Once again thankyou GXMPLX for your sensible and practical advice, I am most grateful. I have caught the scent of a particular global HVAC & R supplier who may have what I seek. I will let you know how I get on.