M. Esen, H. Esen, Experimental investigation of a two-phase closed thermosyphon solar water heater, Solar Energy, Vol. 79, No. 5, pp. 459-468, 2005.
 S. Fathollahi, H. Safarzadeh, Simulation study on the thermal performance of a direct-expansion solar-assisted heat pump for water heating in Kermanshah climate, Modares Mechanical Engineering, Vol. 15, No. 12, pp. 232-242, 2015. (in Persian)
 T. Yousefi, E. Shojaeizadeh, F. Veysi, S. Zinadini, An experimental investigation on the effect of pH variation of MWCNT-H2O nanofluid on the efficiency of flat plate solar collector, Solar Energy, Vol. 86, No. 2, pp. 771-779, 2012.
 S. Kalogirou, Prediction of flat plate collector performance parameters using artificial neural networks, Solar Energy, Vol. 80, No. 3, pp. 248-259, 2006.
 S. Kalogirou, Solar thermal collectors and applications, Progress in Energy and Combustion Science, Vol. 30, No. 3, pp. 231-295, 2004.
 A. Noghrehabadi, E. Hajidavalloo, M. Moravej, an experimental investigation on the performance of a symmetric conical solar collector using SiO2/water nanofluid', Transp Phenom Nano Micro Scales, Vol. 5, No. 1, pp. 23-29, 2016.
 Y. Tian, C. Y. Zhao, a review of solar collectors and thermal energy storage in solar thermal applications, Applied Energy, Vol. 104, pp. 538-553, 2013.
 E. Zambolina, D. Del, Experimental analysis of thermal performance a flat plate and evacuated tube solar collectors in stationary standard and daily condition, Solar Energy, Vol. 84, No. 8, pp. 1382-1396, 2010.
 R. Bertocchi, J. Karni, A. Kribus, Experimental evaluation of a non-isothermal high temperature solar partier receiver, Energy, Vol. 29, No. 5, pp. 687-700, 2004.
 MS. Bohn, KY. Wang, Experiments and analysis on the molten Salt direct absorption receiver concept, Journal of Solar Energy Engineering, Vol. 110, No. 1, pp. 45-51, 1988.
 T. Fend, R. Pitz-paal, O. Reutter, J. Bauer, B. Hoffschmid, two novel high-porosity materials as volumetric receivers for concentrated solar radiation, Solar Energy Materials and Solar Cells, Vol. 84, No. 1, pp. 291-304, 2004.
 H. Tyagi, P. Phelan, R. Prasher, predicted efficiency of a low-temperature nanofluid-based direct absorption solar collector, Journal of Solar Energy Engineering, Vol. 131, No. 4, pp. 0410041-7, 2009.
 E. Natarajan, R. Sathish, Role of nanofluids in solar water heater, International Journal of Advanced Manufacture and Technology, Vol. 1, pp. 3-7, 2009.
 E. Sani, L. Mercatelli, S. Barison, C. Pagura, F. Agresti, L. Colla, and P. Sansoni, Potential of carbon nanohorn-based suspensions for solar thermal collectors, Solar Energy Materials and Solar Cells, Vol. 95, No. 11, pp. 2994-3000, 2011.
 H. Mousazaeh, A. Keyhani, A. Javadi, H. Mobli, K. Abrinia, A. Sharifi, A A review of principal and sun-tracking methods for maximizing solar systems output, Renewable and Sustainable Energy Reviews, Vol. 13, No. 8, pp. 1800-1818, 2009.
 F. Gaspar, M. Balan, L. Jantchi, V. Ros, Evaluation of global solar radiation received by a spherical solar collector, Bulletin UASVM Agriculture, Vol. 69, No. 2, pp. 128-135, 2012.
 I. Pelece, U. Iljins, E. Ziemelis, I. Ziemelis, Theoretical calculation of energy received by semi-spherical solar collector, Proceeding of the International Scientific Conference of Engineering of Agricultural Technologies, Latvia. P: 263-269, 2008.
 B. Samanta, K. Balushi, Estimation of incident radiation on a novel spherical solar collector, Renewable Energy, Vol. 14, No. 1, pp.241-247, 1998.
 N. Kumar, T. Chavad, H. N.Mistry, A trancated pyramid non-tracking type multipurpose domestic solar cooker/hot water system, Applied Energy, Vol. 87, No. 2, pp. 471-477, 2010.
 A. Noghrehabadi, E. Hajidavalloo, M. Moravej, An experimental investigation of performance of a 3-D solar conical collector at different flow rates, Journal of Heat and Mass Transfer Research, Vol. 5, No. 1, pp. 23-29, 2017.
 ASHRAE Standard 93-86. Methods of testing and determine the thermal performance of solar collectors. Atlanta, GA, USA, 1986.
 T. Yousefi, F. Veysi, E. Shojaeizadeh, S. Zinadini, An experimental investigation on the effect of Al2 O3 –H2 O nanofluid on the efficiency of flat plate solar collectors, Renewable Energy, Vol. 39, No. 1, pp. 293-298, 2012.
 Duffie, J. A. Beckman. W. A. Solar Engineering of Thermal Processes. Fourth edition. Wiley, 2013.
 T. Yousefi, F. Veysi, E. Shojaeizadeh, and S. Zinadini, An experimental investigation on the effect of pH variation of MWCNT- H2 O nanofluid on the efficiency of a flat plate solar collector, Solar Energy, Vol. 86, No. 8, pp. 771-779, 2012.
 Do. Ango, AC. Mintsa, M. Medale, C. Abid, Optimization of the design of a polymer flat plate solar collector, Solar Energy, Vol. 87, pp. 64-75, 2013.
 C. Cristofari, G. Notton, P. Poggi, A. Louche, Mmodeling and performance of a copolymer solar water heating collector, Solar Energy, Vol. 72, No. 2, pp. 99-112, 2002.