TY - JOUR
TI - Theoretical and experimental investigation of the evacuated tube solar water heater system
AU - Sakulchangsatjatai Phrut
AU - Wannagosit Chaiwat
AU - Kammuang-Lue Niti
AU - Terdtoon Pradit
JN - Thermal Science
PY - 2020
VL - 24
IS - 2
SP - 795
EP - 808
PT - Article
AB - In this study, the evacuated tube solar water heater (ETSWH) system using  thermosyphon has been investigated experimentally as well as theoretically.  Solar radiation and ambient temperature data from Chiang Mai province were  used for the modeling system by Explicit Finite Difference Method (EFDM).  The effects of thermosyphon diameters and number of evacuated tubes on the  net saving of solar water heater system were analyzed. The mathematical  results showed that the optimal number of evacuated tubes and thermosyphon  diameter occurs at 8 evacuated tubes, which are 15.88 mm of evaporator  diameter and 22.22 mm of condenser diameter under personal hygiene  conditions. The solar water heater system at optimal parameters was  constructed and tested for the system prototype. The theoretical results  were validated by the experimental results. It was found that the  theoretical results can be used to predict temperature, heat transfer rate,  and thermal efficiency to show good agreement with the experimental results  as well as previous research. The experimental and theoretical results  showed that the maximum temperature for hot water was 65.25oC and 71.66oC,  respectively. Moreover, the thermal efficiency of the system based on the  theoretical result was 60.11%, with relative error being about 3.04% of the  experimental result.