The relations between surface roughness and heat
absorption capability for solar collector were investigated. For
these purposes, 3 kinds of materials (copper, aluminum, iron),
5 kinds of surface roughness (scrubber, alumina sand #80,
#200, #400, glass bead) and 2 kinds of surface treatment (black chrome plating, copper black coating) were used to
find optimal conditions. As the results, it was confirmed that
the optimal relations between surface roughness and surface
treatment as well as optimal materials were needed. Further,
heat absorption capability was showed good results in cases
of copper materials, glass bead and black chrome plating.
The thermal performance for test system with evacuated
tubular solar collector was experimentally investigated to
obtain the basis data for improving solar collector. The
system was designed using CATIA and tested using
evacuated tubular solar collector. Numerical analysis was
performed using ANSYS Fluent V.13 for glass evacuated
tubular solar collector.
The performances of solar collectors with single and double
evacuated tube were experimentally compared. The solar
collector with single evacuated tube consists of radiation fin,
heat pipe, absorber plate, glass tube, cap and regulating valve,
and so on. Surface treatment was conducted for heat pipe and
absorber plate with black chrome plating and copper black
coating. As the results, the performance of solar collector with
single evacuated tube showed good results compared that of
double evacuated tube. Absorber plate played a positive role in
performance and showed increase of about 28%. Further
performance in solar collector depends on vacuum degree and
vacuum degree has to be considered economical efficiency as well as performance.
The merits of X-L pipe boiler with electric heat line were
investigated. The electric heat line was inserted into inside of
X-L pipe and voltage was impressed to electric heat line. The
characteristics of X-L pipe boiler and mechanism of heat
generation were investigated by changing of number of electric
heat line and voltage. The economical efficiency was evaluated
by comparing heating cost of X-L pipe boiler with those of
kerosene boiler and natural gas boiler, respectively.
The performance of hybrid heating system, which consisted
of solar collector with thermosyphon tube and X-L pipe boiler,
was investigated. As the results, efficiency of solar collector
with thermosyphon tube was higher 20.7% than that of double
tube, mainly due to its structural characteristics.