Solar Water Heating by Two-Phase Thermosyphon Working with Methanol

• 作 者: MAIslam;MARSarkar;MARKhan;
• 机 构: Department of Mechanical Engineering BUET,Dhaka-1000,Bangladesh
• 出 处: 第2届中国国际可再生能源设备与技术国际研讨会
• 发表日期: 2005年期

Experiments are conducted with a two-phase loop thermosyphon in which a flat-plate solar collector acts as an evaporator and a water tank contains the condensing section of the thermosyphon.Methanol boils at the flat-plate collector, condenses at the water tank transferring latent heat to water,and goes back to the flat-plate collector to be boiled again in order to repeat the cycle. The thermosyphon system is installed at BUET, Dhaka, Bangladesh (23.7~ north latitude) where the average solar radiation is in the range of 3.5-5 kWh/m2 per day. For each of the experiments during May 2003, absorber plate temperatures at different locations, coolant tube temperature, inlet / outlet temperatures of working fluid, water temperature at the water tank and above all solar insolation at a regular interval were recorded and compared with conventional flat-plate collector. From the collected data, performance parameters such as instantaneous collector efficiency and heat removal factors are calculated and analyzed.