MATLAB Simulation of air conditioner in openmodelica/matlab?

AI Thread Summary
The discussion revolves around simulating a vapor compression cycle system for an air conditioner using either MATLAB or OpenModelica. The user seeks to validate a control algorithm for a conventional air conditioning system and is uncertain about which software to use for simulation. They have a basic understanding of thermal systems, and their project is a master's thesis that combines electrical and thermal engineering. The challenge lies in incorporating both control and thermal systems effectively. MATLAB allows for quick control system development but requires building the thermal model from scratch, while OpenModelica offers predefined models for components like compressors and heat exchangers but poses a learning curve due to the user's unfamiliarity with the software. The discussion emphasizes the need for detailed input data and performance models to ensure accurate simulation outcomes, suggesting that this project could be complex and potentially at a master's thesis level.
srinaath
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am trying to simulate air conditioner in open modelica and matlab.. is there any library like hvac so that i can do the simulation in mush easier way...
 
Yes, further information would help - the question is very vague. What about the air conditioner are you trying to simulate? What input information do you have?
 
russ_watters said:
Yes, further information would help - the question is very vague. What about the air conditioner are you trying to simulate? What input information do you have?
hi russ, am trying to simulate simple vapor compression cycle system- compressor, evaporator, expansion (electronic type)
and condenser...and control system...
 
srinaath said:
hi russ, am trying to simulate simple vapor compression cycle system- compressor, evaporator, expansion (electronic type)
and condenser...and control system...
That isn't good enough: That could be an minute's, day's, month's or years' worth of work. There is no way to know unless you tell us, specifically, what you want to know, why, how accurate, and on what information you base it. I am an HVAC engineer: I do that sort of modeling every day.

Why are you trying to model this system? And to repeat from my last post: what input information do you have?

You need to tell us:
"I want to input XXXXX"
and
"I need it to output YYYY"

Sample answer:
1.3 kW/Ton
Is that what you need?
 
russ_watters said:
That isn't good enough: That could be an minute's, day's, month's or years' worth of work. There is no way to know unless you tell us, specifically, what you want to know, why, how accurate, and on what information you base it. I am an HVAC engineer: I do that sort of modeling every day.

Why are you trying to model this system? And to repeat from my last post: what input information do you have?

You need to tell us:
"I want to input XXXXX"
and
"I need it to output YYYY"

Sample answer:
1.3 kW/Ton
Is that what you need?

Russ, sorry that i didn't mention my objective clearly...i need to validate my control algorithm developed for conventional air conditioner by simulation. by conventional air conditioner, i mean normal on/off compressor system...i thought i could simulate the actual air conditioner...so when i feed my control system i can check how they are responding...like i will be measuring suction pressure and temperature, response time of EXV, etc...
 
This is potentially very difficult. I ask again: what input data do you have? I'm guessing at this point that you don't even have a particular air conditioner in mind, much less detailed information about its performance?

You will need to pick an air conditioner and either obtain or generate a detailed performance model (how it performs in different conditions). Then you'll need to pick a room or building it is conditioning and create a load model to apply to the performance model. Alternately, if there is a real air conditioner and building somewhere that you can obtain performance data from, you can use that (some companies keep detailed performance trend data). Then you can apply your control algorithm to that.

Doing this right is probably a masters thesis level type of project.
 
russ_watters said:
This is potentially very difficult. I ask again: what input data do you have? I'm guessing at this point that you don't even have a particular air conditioner in mind, much less detailed information about its performance?

You will need to pick an air conditioner and either obtain or generate a detailed performance model (how it performs in different conditions). Then you'll need to pick a room or building it is conditioning and create a load model to apply to the performance model. Alternately, if there is a real air conditioner and building somewhere that you can obtain performance data from, you can use that (some companies keep detailed performance trend data). Then you can apply your control algorithm to that.

Doing this right is probably a masters thesis level type of project.

you are right russ..this is my project for master thesis...well actually am an electrical and electronics engineer and i have some basic understanding of thermal system...the project is combined with electrical and thermal department...i will be doing the controls part while there is thermal guy, he has done load calculation of particular city for particular room and he has designed the air conditioner details for example heat excahnger's capacity, fins, what type of compressor to be used,etc ... now we are in simulation part..we have done our mathematical modelling but we are stuck to whether it will be suitable to use MATLAB or openmodelica...because we need to incorporate both control system and thermal system... for example say matlab, we can do control system within minutes but we have to design thermal system from scratch..but if you consider openmodelica there is predefined model for compressor, heat exchanger,etc,major drawback is both of us are not familiar with modelica...whether to go with MATLAB which am familiar and build the thermal part or go with openmodelica and learn that software... .. moreover we will building a small prototype for proof of concept.. we are confused about the right software to be used
 
srinaath said:
you are right russ..this is my project for master thesis...well actually am an electrical and electronics engineer and i have some basic understanding of thermal system...the project is combined with electrical and thermal department...i will be doing the controls part while there is thermal guy, he has done load calculation of particular city for particular room and he has designed the air conditioner details for example heat excahnger's capacity, fins, what type of compressor to be used,etc ... now we are in simulation part..we have done our mathematical modelling but we are stuck to whether it will be suitable to use MATLAB or openmodelica...because we need to incorporate both control system and thermal system... for example say matlab, we can do control system within minutes but we have to design thermal system from scratch..but if you consider openmodelica there is predefined model for compressor, heat exchanger,etc,major drawback is both of us are not familiar with modelica...whether to go with MATLAB which am familiar and build the thermal part or go with openmodelica and learn that software... .. moreover we will building a small prototype for proof of concept.. we are confused about the right software to be used
Interesting simulation. I think modelica is way simpler because tools and equipment have been predefined(also the script). All you need is some time to master the software and there is not much video tutorials on youtube for that, so, you gotto learn from scratch.
 
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