TY - JOUR
T1 - Heat retaining integrated collector storage solar water heater with asymmetric CPC reflector
AU - Souliotis, Manolis
AU - Quinlan, Patrick
AU - Smyth, Mervyn
AU - Tripanagnostopoulos, Yiannis
AU - Zacharopoulos, Aggelos
AU - Ramirez, Miguel
AU - Yianoulis, Panagiotis
PY - 2011
Y1 - 2011
N2 - A novel integrated collector storage solar water heater (ICSSWH) was designed, optically analysed and experimentally studied. The unit was based around a heat retaining ICS vessel design consisting of two concentric cylinders mounted horizontally inside a stationary truncated asymmetric compound parabolic concentrating (CPC) reflector trough. The annulus between the cylinders was partially evacuated and contained a small amount of water, which changed phase at low temperature, producing a vapour and creating a thermal diode transfer mechanism from the outer absorbing surface to the inner storage vessel surface. The absorbing outer vessel surface covered with selective absorber film and was partially exposed to solar radiation. The remaining vessel surface area (including the vessel ends) was thermally insulated to improve heat retention during the night. Curved reflectors with a high reflectance along with high transmittance glazing were also used to improve effective operation of the ICS system. The thermal behaviour of the ICS system was compared to that of a Flat Plate Thermosiphonic Unit (FPTU). The experimental results showed that the ICS system is as effective during daily operation as it is during the night. Furthermore, the thermal loss coefficient during night gives similar values between the ICS system and FPTU.
AB - A novel integrated collector storage solar water heater (ICSSWH) was designed, optically analysed and experimentally studied. The unit was based around a heat retaining ICS vessel design consisting of two concentric cylinders mounted horizontally inside a stationary truncated asymmetric compound parabolic concentrating (CPC) reflector trough. The annulus between the cylinders was partially evacuated and contained a small amount of water, which changed phase at low temperature, producing a vapour and creating a thermal diode transfer mechanism from the outer absorbing surface to the inner storage vessel surface. The absorbing outer vessel surface covered with selective absorber film and was partially exposed to solar radiation. The remaining vessel surface area (including the vessel ends) was thermally insulated to improve heat retention during the night. Curved reflectors with a high reflectance along with high transmittance glazing were also used to improve effective operation of the ICS system. The thermal behaviour of the ICS system was compared to that of a Flat Plate Thermosiphonic Unit (FPTU). The experimental results showed that the ICS system is as effective during daily operation as it is during the night. Furthermore, the thermal loss coefficient during night gives similar values between the ICS system and FPTU.
KW - Integrated collector storage solar water heaters (ICSSWH)
KW - Compound parabolic concentrating (CPC) reflector troughs
KW - Optical study
KW - Thermal performance
U2 - 10.1016/j.solener.2011.07.005
DO - 10.1016/j.solener.2011.07.005
M3 - Article
VL - 85
SP - 2474
EP - 2487
JO - Solar Energy
JF - Solar Energy
SN - 0038-092X
IS - 10
ER -