Message Board Thread - "Solar Collector measuring wiht IR camera ?"

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Solar Collector measuring wiht IR camera ? Rabih 6/16/2004
Im Working in a Solar Institute and i have to measure the Heat losses inside the Solar Collector ( Thermal) by using an Infrared Camera and this collector have a GLASS cover which cause too much problems to measure the heat loses inside by an IR camera ,so im suggesing tom remove the Glass cover and replace it by a Teflon ,or Makloron cover .so my question will it work or not and why ?
 
Re:Solar Collector measuring wiht IR camera ? Gary Orlove 6/16/2004
Please indicate which parts of a solar collector you are trying to investigate with the infrared camera. Please refer to the image below:

Gary Orlove
Infrared Training Center
 
Re:Solar Collector measuring wiht IR camera ? Rabih 6/24/2004
hallo im testing the Absorber plate with the IR camera ..
 
Re:Solar Collector measuring wiht IR camera ? Gary Orlove 6/25/2004
It is not clear to me what you are trying to test with the absorber plate, its absorption, emission, heat transfer via water flow, uniformity due to water flow problems, etc.

If you change the cover plate to an IR transparent material, you will change the entire heat transfer situation in the solar collector as glass lets in the short wave radiation but blocks the longwave radiation from the absorber plate itself, thereby raising the efficiency of the solar collector system.

A cover plate material transparent to IR will not block this emitted radiation and will reduce the efficiency and temperature maintained on the absorber plate.

Gary Orlove
Infrared Training Center
 
Re:Solar Collector measuring wiht IR camera ? JKEngineer 6/27/2004
Gary's most recent response echos what I posted on a different thread on the same topic. Reproduced below.
Jack
I want to suggest that you consider another issue in your testing. It is unclear whether it will be an issue from your project description, you will need to evaluate it.

By changing the cover plate material from glass to something else you will change the heat transfer of the system. This will affect the radiation and conduction through the plate and therefore the temperatures of the pipes. If this is a factor in your work then you will need to:

make your measurements using the substitute plates,
correct the measurements analytically back to the conditions of the glass plates.

This can be done with a heat transfer model.

If this is a consideration for your work, then you need to worry about it. If you need help evaluating it, let me know, it is part of the services that I offer.

Jack
Jack M. Kleinfeld, P.E.
Kleinfeld Technical Services, Inc.
Infrared Thermography, Finite Element Analysis, Process Engineering

Bronx, NY 10463

718-884-6644
866-884-6644 toll free
212-214-0919 fax and voice mail

JKEngineer@aol.com or JKEngineer@KleinfeldTechnical.com
come see what we can do for you: http://www.KleinfeldTechnical.com

 
Re:Solar Collector measuring wiht IR camera ? Leo Holm 7/17/2004
I have made investigation with a infrared camera on Solar Collectors.
You can’t measure directly at the glass surface, you shall paint the surface, or use black tape, and then you get a well known surface.
In case there is teflon between the glass and the absorber you will not measure the correct temperature on the glass surface because of circulated air between the glass and the teflon.
If you have to measure the water flow, you just go in from the back side of the collector, by make a notch in the back plate of the collector.
The enclosed image shows a glass where there are mounted black tape
 
Re:Solar Collector measuring wiht IR camera ? Rabih 7/19/2004
The problem with measuring the heat transfer via water flow inside the pipes of a Flat solar collector ,when i use the Infrared camera it picture the Glass (the cover) and make too much reflection ,it become as if a mirror ,u can see it in the picture which i have took with my Cam PM 675 ,so how to solve this problem ,shall i paint the glass with some paint that have a color like water or should i remove the whole Glass cover ,i need a direct answer please for this situation .
thanks alot for your help
 
Re:Solar Collector measuring wiht IR camera ? JKEngineer 7/21/2004
If you want to measure the performance of the plate/water system you will have to take the glass off, since the camera you are using is long wave and will not see through the glass reliably. Removing the cover will change the behavior of the system considerably. This can be minimized by substituting a long wave IR transparent cover. There will still be a change in the peformance. For example, the collector plate will radiate back through the transparent cover differently than it does through the glass. However, you can address these differences by modeling the system. My suggestion, which repeats my earlier post, but I hope clarifies it:

1- change to a transparent in the long wave cover, such as a thin film plastic (I think - would need to check the spectra)

2- perform the tests of interest

3 - model the system's heat transfer characteristics based on performance with the transparent cover

4 - change the model to represent a glass cover and repeat the simulation to predict the performance under glass

This gives you a model verified experimentally based on the measurements with the transparent cover and results from that verified model for the system with the glass, which is your objective.

I'd be glad to work with you on this.

Jack
Jack M. Kleinfeld, P.E.
Kleinfeld Technical Services, Inc.
Infrared Thermography, Finite Element Analysis, Process Engineering

4011 Hillman Ave
Bronx, NY 10463

718-884-6644
866-884-6644 toll free
212-214-0919 fax and voice mail

JKEngineer@aol.com or JKEngineer@KleinfeldTechnical.com
come see what we can do for you: http://www.KleinfeldTechnical.com
 


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