Measurement and Analysis of the Temperature of Unheated Underground Garages in Beijing Under Extreme Low Temperature Conditions
Focusing on the argument of whether underground garages in cold zones need centralized heating,an underground garage without heating in Beijing was selected as the research case,and the winter air temperature of the garage was continuously measured for four years.The measurement data were collected for the underground garage temperature changes under the lowest temperature conditions within the past 50 years in Beijing,and low-temperature freezing experiment was conducted on the fire hydrant water pipes.The results show that under the extreme low temperature of-19.6 ℃in the meteorological observatory,the air temperature in over half of the underground first floor area remains above 0 ℃,and the overall air temperature in the underground second floor exceeds 5 ℃.The fire hydrant water pipe without thermal insulation takes 29 h to complete freezing in a low temperature environment of-6 ℃,and 107 h to complete freezing after thermal insulation measure was taken.This indicates that the fire hydrant water pipe with thermal insulation has good low temperature antifreezing ability.Therefore,from the energy-saving and economic standpoint,centralized heating is not necessary for underground garages in cold zones,but the automatic sprinkling system should adopt a pre-action or dry type system,and local antifreezing measures such as thermal insulation and electric heat tracing should still be considered for the fire hydrant water pipe at the area near entrance and exit of the underground first floor.The measurement data and analysis results can provide basis for the heating design and the fire hose antifreeze design of underground garages in cold zones.
NETL
NSTL
万方数据
