[1] Lanzhou Univ Technol, Sch Energy & Power Engn, Lanzhou 730050, Peoples R China
[2] Gansu Key Lab Complementary Energy Syst Biomass &, Lanzhou 730050, Peoples R China
[3] Gansu Key Lab Complementary Energy Syst Biomass &, Lanzhou 730050, Peoples R China
[4] Inst Energy Technol, Solar Energy Dept, N-2007 Kjeller, Norway
[5] Norwegian Univ Sci & Technol, Dept Energy & Proc Engn, NO-7491 Trondheim, Norway