I design a project 3TR solar vapor absorbtion air conditioning system (NH3+H2O) driven by flat plate collector. The system required 120℃ temperature by collector.
Hi Adeel,
You can get related literature here.
https://www.sciencedirect.com/search?qs=120%E2%84%83%20temperature%20by%20flat%20plate%20collector&show=25&sortBy=relevance
Hello,
Actually it is difficult to get 120 C in flat plate collector, we have achieved maximum of around 103 C that too in summer in India. You can try two stage collectors, but I think it won't work though.
Instead you can go for evacuated tube collector, or most useful one would be parabolic concentrated collectors. You can definitely get around 180 C if conditions favours.
Hope this may help you.
Hey dear,
Hope You're doing well. You can achieve but you have to compromise with mass flow rate, but if possible please
go with PTC.
Hello Adeel,
The only types of the solar flat plate collectors than can provide temperatures higher than 100oC are the evacuated tube collectors. The most important issue of this kind of collectors is their high costs. Otherwise, you have to use concentrators which based on the structure and geometry you can use them with or without trackers while, some of them even need to a two-axis tracker.
For more information, please see the attached table.
Kind regards,
Shiva
It is something difficult but it is not impossible. Please take into account an example:
nth=Fr(ta)-FrUl*(Tfm-Tam)/GT
Fr(ta)=0.8
FrUl=4
The previous are generally high values.
In this case, the thermal efficiency is zero if (Tfm-Tam)/GT=0.2
During a summer day, maybe there is Tam=30 and GT=900 for example.
In this gase, the maximum possible operating temperature or stagnation temperature is 210oC. So, you can see that this temperature level is over 120oC that you ask.
More specifically, in your case, for Tfm=120, the thermal efficiency is 40%.
So, for achieving operating at 120oC you need:
a) A high efficient FPC
b) High solar potential
c) High flow rate in order to have maximum FR
d) Operation with a fluid which can be liquid at 120oC. For example pressurized water, thermal oil, or EG for instance.
However, you have to take into account that FPC are mainly used for applications up to 90-100oC, but in some cases they can operate more than 100oC.
It's depend on your system characteristics such as, stagnation temperature, system efficiency....... There are two ways to achieve this temperature: 1 decrease the mass flow rate, 2 increase the reception area of your system.
Hey, you can redesign or change your flat plate. If you are working on Air Heaters, you can use Aluminum soda cans as the absorber and make it a multiple pass system. then, you can achieve a higher temperature.
Check this paper
Conference Paper EXPERIMENTAL INVESTIGATION ON THE PERFORMANCE OF A SOLAR AIR...
hi,
we achieved 144C stagnation temperature with a flat plate collector for a solar radiation of around 700 W/m2. The secret is actually a combination of several aspects:
1. Double glazing with a gap of 40 mm or more using solar glass (low absorption)
2. 100 mm foam insulation on sides, glass plate corner and back.
Our absorber was not really well built, so my guess is that the performance can be improved.
Alternatively have a look at oekotech.biz, their HT collector can get you 120C
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