| Title |
Analysis of Heating and Domestic Hot Water Load for Adjusting the Output Range of Individual Gas-fired Boilers for Low-Energy Apartment Buildings |
| Authors |
김상엽(Kim, Sang-Yeop) ; 장형문(Zhang, Xinwen) ; 김찬희(Kim, Chan-Hee) ; 최지수(Choi, Ji-Su) ; 이규남(Rhee, Kyu-Nam) ; 정근주(Jung, Gun-Joo) |
| DOI |
https://doi.org/10.5659/JAIK.2021.37.11.237 |
| Keywords |
Apartment building; Heating load; Domestic hot water load; Part load; Boiler output; Output range; Turn-down ratio |
| Abstract |
In Korea, it is common to determine the capacity of individual gas-fired boilers based on the floor area or unit heating load of residential
buildings. With this approach, the current tendency of heating load reduction can not be taken into account when sizing the individual
gas-fired boilers for low-energy apartment buildings. Most of the low-energy apartment buildings might be equipped with over-sized boilers,
which would cause the boiler to operate with low efficiency particularly under part load conditions. As the over-sized boilers can deteriorate
the energy saving performance of low-energy apartment buildings, this study was conducted to suggest the necessity of adjusting the output
range of individual gas-fired boilers. For this purpose, heating and domestic hot water load of apartment buildings were analyzed considering
the historical change of energy saving design standards. The analyzed loads were compared with the output range of household gas-fired
boilers currently available on the market. The results showed that the heating output of the boilers is over-sized, even though the heating load
has been reduced by 53%. It was found that the part-load output of boilers was significantly higher than the heating load, which would lead
to the reduced efficiency during the part load conditions. It was also found that the individual room control can increase the difference
between the boiler part-load output and heating load. Therefore, it is necessary to adjust the output range of boilers by lowering the part-load
output and to increase the turn-down ratio of boilers in order to improve the energy efficiency of low-energy apartment buildings. |