ZEMCH 2019 International Conference Proceedings April.2020 | Page 384
equations for various components were solved using ODE solver in Matlab software [16]. The following
assumptions have been considered during mathematical modeling:
1) There is no change in physical dimensions and material properties of the collector components.
2) For parallel tube heat exchanger, temperature and flow rate in all tubes were taken as same.
3) The ohmic losses in the PV cells and edge losses are neglected.
4) All heat transfer coefficient were calculated in real‐time [7].
PV cells (glass to glass)
M � C � �dT � �dt� � Gα � τ � PF � � � h ���� A �� �T � � T � ��h �� A �� �T � � T � � � h �� A �� �T � � T � � � A �� h �� �T � �
T � � � A �� h �� �T � � T � � � h �� A �� �T � � T � � � h �� A �� �T � � T � �
(1)
PV cells (glass to tedlar)
M � C � �dT � �dt� � Gα � τ � PF � Gτ � α ��� �� � PF� � � � h ���� A �� �T � � T � ��h �� A �� �T � � T � � � h �� A �� �T � �
T � � � A �� h �� �T � � T � � � �A �� h �� �T � � T � � � h �� A �� �T � � T � � �h �� A �� �T � � T � �
(2)
where G is the irradiance and PF is the packing factor. α � and τ � are the absorptivity of the
solar cells and transmissivity of the glass cover, respectively. h ���� is the convection heat transfer
coefficient because of wind [17]. h �� is the radiation heat transfer coefficient between solar cell and
ambient air, and h �� is the conduction heat transfer coefficient between solar cells and the tube. h �� is
the convection heat transfer coefficient between solar cell and the circulating air, and h �� is the
convection heat transfer coefficient between tube and the circulating air. h �� is the radiation heat
transfer coefficient between the solar cell and the back panel, and h �� is the convection heat transfer
coefficient between tube and the back panel.
Tube
M � C � �dT � �dt� � h �� A �� �T � � T � � � A �� h �� �T � � T � � � A �� h �� �T � � T � � � h �� A �� �T � � T � �
(3)
h �� is the convection heat transfer coefficient between the tube and the fluid.
Circulating water
M � C � �dT � �dt� � ṁ � C � �T ��� � T ���� �� A �� h �� �T � � T � �
(4)
ṁ � and C � are the mass flow rate and specific heat of the pipe fluid. T ���� and T ��� are the inlet and
outlet temperature of the pipe fluid.
Circulating air
M � C � �dT � �dt� � ṁ � C � �T ��� � T ���� � � A �� h �� �T � � T � � � A �� h �� �T � � T � � � h �� A �� �T � � T � � (5)
ṁ � and C � are the mass flow rate and specific heat of the circulating air. T ���� and T ��� are the inlet
and outlet temperature of the circulating air.
Back panel
M � C � �dT � �dt� � h �� A �� �T � � T � � � h �� A �� �T � � T � � � h �� A �� �T � � T � � � h �� A �� �T � � T � �
373
(6)
ZEMCH 2019 International Conference l Seoul, Korea