Development of a numerical simulation system toward comprehensive assessments of urban warming countermeasures including their impacts upon the urban buildings energy demands

摘要

One of the detrimental effects caused by the urban warming phenomena is the increase of energy consumption due to the artificial air conditioning of buildings in summer. In greater Tokyo, the temperature sensitivity of the peak electricity demand reaches up to 3%/℃ in recent years, and about 1.5GW of new demand is required as the daily maximum temperature increases by 1.0℃. This huge demand of summer electricity is considered to be one of the common characteristics in big cities of Asian countries. In order to simulate this increase of cooling energy demands and to evaluate urban warming countermeasures from the viewpoint of buildings' energy savings, a numerical simulation system was developed adopting a new one-dimensional urban canopy meteorological model coupled with a simple sub-model for the building energy analysis. Then, the system was applied to Ootemachi area, a central business district in Tokyo. Preliminary verification of the simulation system using observational data on the outdoor and indoor thermal conditions showed good results. Simulations also indicated that the cutoff of the anthropogenic heat from air conditioning facilities could be produce a cooling energy saving up to 60o with the outdoor air temperature decrease by more than 1 C in the summer urban canopy over Ootemachi area.