typical refrigeration cycle

[Lc_shi]

Hi sirs
is there a kind of software which can simulate a typical cycle of refrigeration system? while you change any parameter ,system can reach a new balance point like a real machine operating.

Any clues,thanks

regards
LC:)

[wambat]

Lc Shi This may be what your looking for
http://energy.sdsu.edu/testcenter/index.html Roger

[Lc_shi]

It's really a good web.
I'd like to learn it.

How about you experience on it?

thanks
LC

[US Iceman]

HI LC,

MY experiences with system modeling is that you will have to write specific "modules" for each system component.

As an example for a compressor: This module would have to include capacity and power input calculations for changes in rotational speed, suction superheat, re-balancing of the suction and discharge pressures, refrigerant used, etc. I have done this for a computer program once before for a screw compressor and it was a LOT of work.

Similar modules would also have to be created for evaporators, condensers, and the refrigerant metering device.

Quite a project to begin.

There are some programs used in the chemical engineering field for system modeling bu they are very expensive. These are intended for refineries and other processes. They have modules you can add to a diagram. When the individual modules are linked together you can "run" the system and change operating parameters.

[wambat]

It's really a good web.
I'd like to learn it.

How about you experience on it?

thanks
LC
I joined as an academic instructor which is free but is limited unless i agree to pay some money but it's not expensive. I am still learning how to use it properly but the tutorals are good , they olny take time however. I believe once you know how to use it you can simulate any thermodinamic process and find a solution.:)

[wambat]

HI LC,

MY experiences with system modeling is that you will have to write specific "modules" for each system component.

As an example for a compressor: This module would have to include capacity and power input calculations for changes in rotational speed, suction superheat, re-balancing of the suction and discharge pressures, refrigerant used, etc. I have done this for a computer program once before for a screw compressor and it was a LOT of work.

Similar modules would also have to be created for evaporators, condensers, and the refrigerant metering device.

Quite a project to begin.

There are some programs used in the chemical engineering field for system modeling bu they are very expensive. These are intended for refineries and other processes. They have modules you can add to a diagram. When the individual modules are linked together you can "run" the system and change operating parameters.
Iceman you need to look at the web site

[Peter_1]

Wambat,

I downloaded also the academic version and I don't think you can't simulate the behavior in a real cool process.
I think what Lc_shi wants is that he can see what happens with the equilibrium point when for example subcooling increases.
This is something difficult to calculate.
You need the curves for each specific item you used in the system and some curves can't be made nor found.

[US Iceman]

Hi guys,

Here is a link Josip posted some time ago.

http://www.frigosoft.no/frigosim/

It is also expensive but it does look like it was built for refrigeration systems.

[Lc_shi]

Yeah，I download it but not received demo llicense.

[mxstar]

I use Engineering Equation Solver (EES), also known as Ease for modelling refrigeration cycles. It is great at solving simultaneous equations and has the thermophysical property data for lots of fluids.

[Peter_1]

CAn you provide a link please?

[US Iceman]

Peter,

Here is the link for the EES program. I have this program also and find it very useful. You have to create your own modeling equations for the refrigeration system.

You can curve fit any data such as compressor ratings or others and use it within the program. EES already has a large group of refrigerant and other fluid properties that you can use.

There is a learning curve to this program, but after you become familar with it I think you will like it.

http://www.fchart.com/ees/ees.shtml

[Tor Henriksen]

Sirs

I think the program you are looking for is this one. Its very easy to use and you have every thing you needs to simulate what ever you want.
Down load it from www.et.du.dk/CoolPack

[Josip]

Hello,


Tor Henriksen
Sirs

I think the program you are looking for is this one. Its very easy to use and you have every thing you needs to simulate what ever you want.
Down load it from www.et.du.dk/CoolPack

I think this is right becuse:

The programs in CoolPack covers the following simulation purposes:
• Calculation of refrigerant properties (property plots, thermodynamic & thermophysical
data, refrigerant comparisons)
• Cycle analysis – e.g. comparison of one- and two-stage cycles
• System dimensioning – calculation of component sizes from general dimensioning
criteria
• System simulation – calculation of operating conditions in a system with known
components
• Evaluation of operation – evaluation of system efficiency and suggestions for reducing
the energy consumption
• Component calculations – calculation of component efficiencies
• Transient simulation of cooling of an object – e.g. for evaluation of cooling down
periods
To make it easier to get an overview of the programs in CoolPack we have chosen to divide the
programs into three main groups (Refrigeration Utilities, EESCoolTools and Dynamic).

Here you can download Tutorial or CoolPack program, as you like:

http://www.et.web.mek.dtu.dk/Coolpack/UK/download.html

Best regards,

Josip

[Dan]

is there a kind of software which can simulate a typical cycle of refrigeration system? while you change any parameter ,system can reach a new balance point like a real machine operating.

Hi, LC. I am just curious what particular instances you experience where you see this to be a valuable tool.

For example, are you wanting to design equipment? That's the first thing that comes into my mind. And if so, what particuar problems are you trying to overcome? For example, are you concerned about the dimensions of heat exchangers and compressors because of physical limitations?

Or are you looking at such a tool in order to suggest replacement equipment to a customer?

I am just curious.:)

[Lc_shi]

Hi Dan
Yes, my work is equipment design. At concept stage I need to evaluate the design feasibility. Usually we can only calculate the parememters at 1 or 2 states.It's hard to predict the dynamical performance:p. Of course,the final design should be by prototype test. However,a good and practical simulation tool is of great help:)

rgds
LC

[US Iceman]

It's hard to predict the dynamical performance

This is why I liked to do simulations on equipment performance, especially before the product or system is designed.

This allows you see the interaction of the various parameters in the dynamic situations. Then you can change one aspect of the component or system to achieve higher performance values.

I was involved in one project where we did this for a screw compressor. By changing the geometry of certain features we could see the result before designing castings. Sort of like CFD.

[Peter_1]

The EES program Mxstart mentioned - I thought I had seen the logo of F-Chart and the box with the 3 E's somewhere - is already included in Coolpack.
LC-Shi!!!

[Josip]

:):):) Hello Peter_1:):):)

Here we use some pills, don't know what could be the name in english (what is not so important) but they act as "antiforgetting" pills.

NHF, please ;)


Dear LC-Shi...

FrigoSim demo licence works only (as I remember) with salt water and R22 what is not too much useful and full version is quite expensive. It is better to stay in touch with CoolPack and some other free programs. See my post under "Free sofware, hm but not all" maybe you can find something there

But if you need to do the serious job/project I think company should find the budget to buy the tools ;),
what you mean?

Best regards,

Josip

[US Iceman]

Hi Peter,

You are correct. Coolpack is based on the EES program.

I wish the EES program could draw the same nice looking log-PH diagrams you can generate with the refrigeration utilities program in Coolpack.

[JKProSoft]

I use a great program from Solkane. You can access it at: http://www.solvay-fluor.com/library/bysection/result/0,0,-_EN-1000040,00.html