[TRNSYS-users] Type 74 CPC Collector parameters

[Shahrdad JavidRad]

Hello,

I have startet to simulate a solar hot water system. I am using a CPC collector (solar thermal collectors Type 74 in TRNSYS). In this type there are many parameters that I can not find in any collector report. This parameters are listed below:


Collector fin efficiency
factor: The fin efficiency
is a measure of the heat transfer from the fin to the maximum possible heat
transfer from the fin. The maximum heat transfer from the fin
would occur if the fin was uniformly at the base temperature.



Overall Loss Coefficient [kJ/hr.m^2.K]: The loss coefficient of
the solar collector per unit aperature area.

 

Wall reflectivity: The reflectivity of the
walls of the CPC collector. The reflectivity is a ratio of the reflected radiation to
the toal incident radiation.

 

Half-acceptance angle: The half-acceptance angle
of the CPC collector. The CPC collects both beam and diffuse radiation which approach
the aperature within the critical angle, or half-acceptance angle.

 

Truncation ratio: A full CPC is one in which
the walls extend upward to a height h which gives an aperature area  of 1/sin(halfacceptance angle) times the
absorber area. Optimal
concentration is achieved in a full CPC, but a very large reflector is required. Most CPC's are truncated to some fraction of
this height hbar. Truncation ratio = hbar/h

 

 

Absorptance of absorber
plate: The absorptance of
the absorber plate of the solar collector. The absorptance is a ratio of the
amount of radiation absorbed
by a surface to the total radiation incident on the surface.

 

Index of refraction of
cover: The index
of refraction of the material covering the solar collector absorber plate.

 

Extinction coeff. Thickness
product: The
product of the extinction coefficient and the thickness of one of the glazings
covering the solar collector absorber plate.

 
Does anyone have experiences regarding to using of CPC collectors in TRNSYS?





Shahrdad

 		 	   		  
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