TY - JOUR
T1 - Study of the characteristics of the separated gravity heat pipe of a self-activated PCM wall system
AU - Xu, Dawei
AU - Yan, Tian
AU - Xu, Xinhua
AU - Wu, Wei
AU - Zhu, Qiuyuan
PY - 2024/7/1
Y1 - 2024/7/1
N2 - Self-activated phase change material (PCM) wall integrated with radiative sky cooling (RSC) is a novel wall system that uses natural energy directly for low-energy buildings to support carbon peaking and neutrality goals. A separated gravity heat pipe (SGHP) is an effective heat transfer component for heat transport from the wall body to the radiative cooler without using mechanical energy. Its heat transfer characteristics affect the thermal performance of the wall system. In this study, a numerical Volume of Fluid (VOF) model of the SGHP is established. The thermal and flow characteristics under the small temperature difference boundary of building scenarios are simulated and analyzed. Results show that the average temperature of the working fluid inside the SGHP in the “steady stage” is about 26.3 °C when the boundary temperature of the evaporation and condensation sections are respectively 28 °C and 20 °C. The heat exchange can reach 356 W/m2 and the flow velocity of the working fluid is about 0.1 m/s. Influences of different evaporation/condensation boundary temperatures on the heat transfer effect are further studied. Compared to increasing the evaporation section temperature, decreasing the condensation section temperature is a better strategy for improving the heat exchange capacity of the SGHP. © 2024 Elsevier Ltd
AB - Self-activated phase change material (PCM) wall integrated with radiative sky cooling (RSC) is a novel wall system that uses natural energy directly for low-energy buildings to support carbon peaking and neutrality goals. A separated gravity heat pipe (SGHP) is an effective heat transfer component for heat transport from the wall body to the radiative cooler without using mechanical energy. Its heat transfer characteristics affect the thermal performance of the wall system. In this study, a numerical Volume of Fluid (VOF) model of the SGHP is established. The thermal and flow characteristics under the small temperature difference boundary of building scenarios are simulated and analyzed. Results show that the average temperature of the working fluid inside the SGHP in the “steady stage” is about 26.3 °C when the boundary temperature of the evaporation and condensation sections are respectively 28 °C and 20 °C. The heat exchange can reach 356 W/m2 and the flow velocity of the working fluid is about 0.1 m/s. Influences of different evaporation/condensation boundary temperatures on the heat transfer effect are further studied. Compared to increasing the evaporation section temperature, decreasing the condensation section temperature is a better strategy for improving the heat exchange capacity of the SGHP. © 2024 Elsevier Ltd
KW - Flow characteristic
KW - Heat transfer characteristic
KW - Low-energy building
KW - Radiative sky cooling
KW - Separated gravity heat pipe
KW - VOF model
UR - http://www.scopus.com/inward/record.url?scp=85191199296&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-85191199296&origin=recordpage
U2 - 10.1016/j.energy.2024.131237
DO - 10.1016/j.energy.2024.131237
M3 - RGC 21 - Publication in refereed journal
SN - 0360-5442
VL - 298
JO - Energy
JF - Energy
M1 - 131237
ER -
