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ABSTRACT
Improving building energy systems is a major research hotspot due to the rising demand for indoor comfort and buildings’ increasing energy consumption. The research object in this work is a high-rise residential building in Nanjing. The photovoltaic system and ground source heat pump system are introduced into the traditional cooling and heating source system for energy-saving design of the building. Based on OpenStudio software, two photovoltaic systems, household photovoltaic panels and centralized rooftop photovoltaic panels, are analyzed in terms of dynamic energy efficiency on a time-by-time and day-by-day basis. In addition, the ground source heat pump system is studied in comparison with conventional split air conditioning system. Meanwhile, the energy-saving performance of systems is analyzed during the cooling, heating and transition seasons. The results showed that both PV systems can afford a total of 39.5% of the electricity demand for lighting and equipment systems throughout the year. The total primary energy consumption per unit area of the optimized building model is 51.17 kWh/(m2·a), which is 35.2% lower than that of the original building model. In addition, the energy replacement rate of the photovoltaic system is 23.7% and the contribution of renewable energy from ground source heat pump is 38.76%, which meets the national standard for near-zero energy buildings.
Nomenclature
| A | = | effective power generation area, m2 |
| C | = | annual electricity production, kWh |
| Ce | = | cumulative annual electricity production, kWh |
| Cw | = | specific heat capacity of water, kJ/(kg·℃) |
| Epv,des | = | total annual end-use energy consumption, kWh |
| Enet,des | = | annual net energy consumption, kWh |
| Eoes,ref | = | annual combined energy consumption, kWh |
| ERES | = | renewable energy, kWh |
| L | = | flow rate, m3/h |
| Q | = | cooling and heating capacity, kW |
| Qc | = | heat displacement to the soil, kW |
| Qelec | = | equivalent calorific value of primary energy consumption required to drive electricity, kWh |
| Qf | = | cooling load, kW |
| Qt | = | heat extraction from the soil, kW |
| Qtra | = | equivalent calorific value of the primary energy required to supply heat and cooling from conventional forms of energy, kWh |
| Qusable | = | total amount of cooling and heating, kWh |
| Qw | = | heating load, kW |
| R | = | annual solar irradiation received, MJ/m2 |
| W | = | power consumption, kW |
| Greek symbols | = | |
| α | = | angle with PV panel and building facade, ° |
| β | = | angle with PV panel and roof level, ° |
| βgp | = | renewable energy contribution, % |
| βpv | = | energy replacement rate |
| ξ | = | photovoltaic conversion efficiency of the PV module, % |
| η | = | combined energy saving rate, % |
| ηs | = | energy saving rate, % |
| ηr | = | substitution rate, % |
| ρ | = | density, kg/m3 |
| △t | = | temperature difference, ℃ |
| Abbreviations | = | |
| COP | = | energy efficiency ratio under heating conditions |
| EER | = | energy efficiency ratio under cooling conditions |
| PV | = | Photovoltaic |
Disclosure statement
No potential conflict of interest was reported by the author(s).
Additional information
Funding
Notes on contributors
Xiangzhong Bao
Xiangzong Bao (1966), Male, Senior Engineer.
Shuyao Lei
Shuyao Lei (1995), Female, Master Degree.
Bo Xu
Bo Xu (1990), Male, Associate Professor; Email: [email protected].