Annual Energy, Exergy, and Environmental Benefits of N Half Covered Concentrated Photovoltaic Thermal (CPVT) Air Collectors

Abstract

In current study, the N identical concentrated photovoltaic thermal (PVT) has been designed where a series connection of N collectors has been adopted for higher outlet temperature of fluid. Here, air has been chosen as a fluid for proposed system. The low concentrator or compound parabolic concentrator (CPC) has been also implemented with photovoltaic thermal (PVT) to increase higher input energy or solar radiation to get much higher temperature from PVT. The air flow rate and no. of collector for CPVT (50% covered by PV module) air collector have been optimized for achieving 97 °C of outlet air temperature as eight number of collector (N = 8 at mass flow rate of 0.06 kg/s). The analysis has been carried out for a clear day condition for New Delhi, India. The proposed system has been useful for space heating or drying an object. Here, the net annual overall energy and exergy have been calculated as 1309.42 and 272.75 kWh, respectively. The electrical gain has also been found as 89.97 kWh. The enviroeconomic study also examined CO₂ emission per annum is reduced by energy production and earned carbon credits. For present system, the earned carbon credits are as 38.73 and 8.06 $/year on the basis of overall thermal energy and overall exergy, respectively.

Appendix

$$U_{tc,a} = \left[ {\frac{1}{{h_{o} }} + \frac{{L_{g} }}{{K_{g} }}} \right]^{ - 1} ;\quad U_{tc,p} = \left[ {\frac{1}{{h_{i} }} + \frac{{L_{g} }}{{K_{g} }}} \right]^{ - 1} ;$$

$$U_{tp,a} = \left[ {\frac{1}{{U_{tc,a} }} + \frac{1}{{U_{tc,p} }}} \right]^{ - 1} + \left[ {\frac{1}{{h_{i}^{'} }} + \frac{1}{{h_{pf} }} + \frac{{L_{i} }}{{K_{i} }}} \right]^{ - 1}$$

$$h_{0} = 5.7 + 3.8V\,{\text{W}}/{\text{m}}^{2} \,{\text{K}};\quad V = 1\,{\text{m}}/{\text{s}} ;\quad h_{i} = 5.7\,{\text{W}}/{\text{m}}^{2} \,{\text{K}};$$

$$h_{i}^{'} = 2.8 + 3V^{'} \,{\text{W}}/{\text{m}}^{2} \,{\text{K}};\quad V^{'} = 1\,{\text{m}}/{\text{s}};\quad \left( {AF_{R} \left( {\alpha \tau } \right)} \right)_{m1} = PF_{2} \left( {\alpha \tau } \right)_{{m,{\text{eff}}}} A_{m} F_{Rm} ;$$

$$\begin{aligned} U_{L1} & = \frac{{U_{tc,p} U_{tc,a} }}{{U_{tc,p} + U_{tc,a} }};\quad U_{L2} = U_{L1} + U_{tp,a} ; \\ U_{L,m} & = \frac{{h_{pf} U_{L2} }}{{F^{'} h_{pf} + U_{L2} }} ;\quad U_{L,c} = \frac{{h_{pf} U_{tp,a} }}{{F^{'} h_{pf} + U_{tp,a} }}; \\ \end{aligned}$$

$$\begin{aligned} PF_{c} & = \frac{{h_{pf} }}{{F^{'} h_{pf} + U_{tp,a} }};\quad PF_{1} = \frac{{U_{tc,p} }}{{U_{tc,p} + U_{tc,a} }}; \\ PF_{2} & = \frac{{h_{pf} }}{{F^{'} h_{pf} + U_{L2} }};\left( {\alpha \tau } \right)_{{c,{\text{eff}}}} = PF_{c} \alpha_{p} \tau_{g } \frac{{A_{ac} }}{{A_{rc} }}; \\ \end{aligned}$$

$$\left( {\alpha \tau } \right)_{{1,{\text{eff}}}} = \left( {\alpha_{c} - \eta_{c} } \right)\tau_{g} \beta_{c} \frac{{A_{am} }}{{A_{rm} }};\quad \left( {\alpha \tau } \right)_{{2,{\text{eff}}}} = \alpha_{p} \tau_{g }^{2} \left( {1 - \beta } \right)\frac{{A_{am} }}{{A_{rm} }};$$

$$\begin{aligned} \left( {\alpha \tau } \right)_{{m,{\text{eff}}}} & = \left[ {\left( {\alpha \tau } \right)_{{1,{\text{eff}}}} + PF_{1} \left( {\alpha \tau } \right)_{{1,{\text{eff}}}} } \right]; \\ A_{c} F_{Rc} & = \frac{{\dot{m}_{f} c_{f} }}{{U_{L,c} }}\left[ {1 - \exp \left( {\frac{{ - F^{'} U_{L,c} A_{c} }}{{\dot{m}_{f} c_{f} }}} \right)} \right]; \\ \end{aligned}$$

$$\begin{aligned} A_{m} F_{Rm} & = \frac{{\dot{m}_{f} c_{f} }}{{U_{L,m} }}\left[ {1 - \exp \left( {\frac{{ - F^{'} U_{L,m} A_{m} }}{{\dot{m}_{f} c_{f} }}} \right)} \right]; \\ \left( {AF_{R} U_{L} } \right)_{1} & = \left[ {A_{c} F_{Rc} U_{L,c} + A_{m} F_{Rm} U_{L,m} \left( {1 - \frac{{A_{c} F_{Rc} U_{L,c} }}{{\dot{m}_{f} c_{f} }}} \right)} \right]; \\ \end{aligned}$$

$$\begin{aligned} \left( {AF_{R} \left( {\alpha \tau } \right)} \right)_{1} & = \left[ {A_{c} F_{Rc} \left( {\alpha \tau } \right)_{{c,{\text{eff}}}} + PF_{2} \left( {\alpha \tau } \right)_{{m,{\text{eff}}}} A_{m} F_{Rm} \left( {1 - \frac{{A_{c} F_{Rc} U_{L,c} }}{{\dot{m}_{f} c_{f} }}} \right)} \right]; \\ K_{k} & = \left( {1 - \frac{{\left( {AF_{R} U_{L} } \right)_{1} }}{{\dot{m}_{f} c_{f} }}} \right); \\ \end{aligned}$$