572
D. Yoshidome et al.
• The amount of heat from solar heat depends on the amount of solar radiation, and
the heat collection efficiency is stable at around 50%.
• We confirmed that the COP of the adsorption type refrigerator using solar heat
does not meet the rated COP = 0.6, and the efficiency decreases when the outside
air temperature becomes lower.
• The geothermal heat pump of store C in summer is about COP = 2 which is about
a half of the COP in winter. The COP of the heat pump of store B is always at a
low level throughout the year.
• The energy utilization rate of the entire system is the lowest in summer at about
50%. This was caused by the increase in power consumption and the decrease in
COP of the geothermal heat pump.
• We confirmed that the air conditioning malfunction at store C in fiscal year 2018
was caused by the increase in the temperature at the entrance to ground heat pump
and the shortage of capacity of ground heat pump. In addition, as the factor that
the entrance temperature of the geothermal heat pump rises, the heat insulation of
the piping was not enough. The temperature rise between the ground heat pump
and ground heat sampling tube was 12 °C.
• The piping temperature in summer is reduced by 2 °C as a result of cold supply
by an adsorption type refrigerator. On the other hand, it was confirmed that the
amount of output of adsorption type refrigerator was about 2–10% compared to
the heat extraction amount.
• We were able to match the heat supply with the heat demand when we adjusted
the angle of solar heat collectors to 15° and reduced them to only 5 units.
References
Agency for Natural Resources and Energy (2019a) Basic items of solar thermal system
[Online]. Available: https://www.enecho.meti.go.jp/category/saving_and_new/attaka_eco/refere
nce/pdf/donyu-kento/donyu-kento_2.pdf [Accessed 5 Sept 2019]
Agency for Natural Resourse and Energy (2019b) Introduction and operation management method
of solar heat utilization system [Online]. Available: https://www.enecho.meti.go.jp/category/sav
ing_and_new/attaka_eco/reference/pdf/donyu-kento/donyu-kento_4.pdf [Accessed 5 Sept 2019]
Agency for Natural Resourse and Energy (2019c) Items to confirm when introducing a solar
heat utilization system [Online]. Available: https://www.enecho.meti.go.jp/category/saving_and_
new/attaka_eco/reference/pdf/donyu-kento/donyu-kento_3.pdf [Accessed 5 Sept 2019]
Herrando M, Markides CN (2016) Hybrid PV andsolar-thermal systems for domestic heat and
power provision in the UK: techno-economic considerations. Appl Energy 161:512–532
Hirata S, Ozaki A, Sumiyoshi D, Hirata T (2016) Modeling of solar water heater and the analysis.
Proc Air Conditioning Sanitary Eng Conf 2:29–32
Horiike S, Nagano K (2015) Design and evaluation of one of the largest ground source heat pump
systems in a large scale retail store. J Environ Eng 709(80):249–258
Japan Heat Supply Business Association (2016) Heat supply business manual 2016 edition, pp
22–23
D. Yoshidome et al.
• The amount of heat from solar heat depends on the amount of solar radiation, and
the heat collection efficiency is stable at around 50%.
• We confirmed that the COP of the adsorption type refrigerator using solar heat
does not meet the rated COP = 0.6, and the efficiency decreases when the outside
air temperature becomes lower.
• The geothermal heat pump of store C in summer is about COP = 2 which is about
a half of the COP in winter. The COP of the heat pump of store B is always at a
low level throughout the year.
• The energy utilization rate of the entire system is the lowest in summer at about
50%. This was caused by the increase in power consumption and the decrease in
COP of the geothermal heat pump.
• We confirmed that the air conditioning malfunction at store C in fiscal year 2018
was caused by the increase in the temperature at the entrance to ground heat pump
and the shortage of capacity of ground heat pump. In addition, as the factor that
the entrance temperature of the geothermal heat pump rises, the heat insulation of
the piping was not enough. The temperature rise between the ground heat pump
and ground heat sampling tube was 12 °C.
• The piping temperature in summer is reduced by 2 °C as a result of cold supply
by an adsorption type refrigerator. On the other hand, it was confirmed that the
amount of output of adsorption type refrigerator was about 2–10% compared to
the heat extraction amount.
• We were able to match the heat supply with the heat demand when we adjusted
the angle of solar heat collectors to 15° and reduced them to only 5 units.
References
Agency for Natural Resources and Energy (2019a) Basic items of solar thermal system
[Online]. Available: https://www.enecho.meti.go.jp/category/saving_and_new/attaka_eco/refere
nce/pdf/donyu-kento/donyu-kento_2.pdf [Accessed 5 Sept 2019]
Agency for Natural Resourse and Energy (2019b) Introduction and operation management method
of solar heat utilization system [Online]. Available: https://www.enecho.meti.go.jp/category/sav
ing_and_new/attaka_eco/reference/pdf/donyu-kento/donyu-kento_4.pdf [Accessed 5 Sept 2019]
Agency for Natural Resourse and Energy (2019c) Items to confirm when introducing a solar
heat utilization system [Online]. Available: https://www.enecho.meti.go.jp/category/saving_and_
new/attaka_eco/reference/pdf/donyu-kento/donyu-kento_3.pdf [Accessed 5 Sept 2019]
Herrando M, Markides CN (2016) Hybrid PV andsolar-thermal systems for domestic heat and
power provision in the UK: techno-economic considerations. Appl Energy 161:512–532
Hirata S, Ozaki A, Sumiyoshi D, Hirata T (2016) Modeling of solar water heater and the analysis.
Proc Air Conditioning Sanitary Eng Conf 2:29–32
Horiike S, Nagano K (2015) Design and evaluation of one of the largest ground source heat pump
systems in a large scale retail store. J Environ Eng 709(80):249–258
Japan Heat Supply Business Association (2016) Heat supply business manual 2016 edition, pp
22–23