Re: [TRNSYS-users] Too high solar efficiency

[Jordi Jove via TRNSYS-users <trnsys-users@lists.onebuilding.org>]

Hi Rami,

Thanks for your answer, but that just reduces the efficiency a little bit to 58%.

- total radiation on tilted surface: 1,93 MWh/m²/year 

- useful energy gain by collectors: 1,12 MWh/m²/year 

I don't know where is the problem I have checked the parameters units and looks correct, Maybe I am not using the right solar collector, but what I would like to simulate is  a normal plate collector surface without movement, always with the same slope.

Looking forward for solving it.

---
Jordi Jové Manonelles

jovejm@gmail.com

2016-07-25 13:51 GMT+02:00 Rami Al-Assad <ramianton@gmail.com>:

Hi Jordi,

I think the problem related to Type 1b as you connect the

Ground reflected diffuse radiation on horizontal --> Ground reflectance

where the ground reflectance is a constant value and mostly equal to 0.2

hope this will solve the problem

Regards,

Rami

On Mon, Jul 25, 2016 at 1:51 PM, Jordi Jove via TRNSYS-users <trnsys-users@lists.onebuilding.org> wrote:

Hi,

I am working in a solar district heating simulation project and I am getting a solar collecotr efficiency over 64%, which is impossible. I am refering to the ratio between incident radiation to the collectors, and the energy gain by them:

total radiation on tilted surface: 1,93 MWh/m²/year 

useful energy gain by collectors: 1,23 MWh/m²/year 

So, I connected something erroneously, but I can not find the right way. I tried Quadratic Collector type1a and type1b and I got the same excessive efficiency.

In the first one TYPE1a the connections with weather data are the following:

      Ambient temperature-->Ambient temperature

      Total radiation on tilted surface-->Incident radiation

In type 1b the connection are the following:

      Ambient temperature-->Ambient temperature

      Total radiation on horizontal --> Total horizontal radiation

      Sky difuse radiation on horizontal --> Horizontal diffuse radiation

      Ground reflected diffuse radiation on horizontal --> Ground reflectance

      Total radiation on tilted surface --> Incident radiation

       Angle of incidence for tilted surface -->  Incident Angle

      Slope of tilted surface --> Collector slope

      

I really need to solve this problem, thanks.

Jordi

---
Jordi Jové Manonelles

jovejm@gmail.com

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Rami Anton Al-Assa'd
Tel: 00962 7 88726129
P.O. Box 151201
ِِJordan 13115 Az Zarqa
E-mail: ramianton@Gmail.com