Application of dynamic loads calculation method based on unit water supply amount per serving in large-scale kitchen facilities

Saburo Murakawa, Hiroshi Takata,  Kazuhiko Sakamoto, Daisuke Ikeda

the 50th CIB Annual International Symposium on Water Supply and Drainage for Buildings

ＣＩＢ 　Ｗ０６２

University of Miami, in Coral Gables, Florida, (USA),

Currently in Japan, with the spread of water-saving plumbing fixtures in buildings, the unit water supply amount used for design, such as water supply amount per total floor area [L/m2/d] and water supply amount per person [L/people/d], is being reviewed. From these unit water supplies, the peak hourly load and maximum instantaneous load used for design are predicted by multiplying them by a set coefficient. However, in a paper on office buildings at the 49th CIB-W062 symposium, the authors showed that this multiplication coefficient varies depending on the actual number of people in the building.
The authors have proposed a dynamic water supply load calculation method that simulates people's cold and hot water usage to statistically predict instantaneous, hourly and daily loads from time-series fluctuations in instantaneous flow rates throughout the day. In this paper, the authors used the unit model of large-scale kitchen facilities (referred to as the conventional method) shown in the calculation program as an example to compare the calculation model set based on the unit water supply amount per serving   obtained from measurements with the conventional method, using office building employee cafeterias and a university student cafeteria as examples.
As a result, it was shown that in two employee cafeterias of office buildings, the daily and hourly loads were similar for both models, but the instantaneous maximum load was smaller due to the lower setting of the water discharge flow rate in the meal serving count model. On the other hand, in a university cafeteria, the statistical values ​​from a meal count model in which the water supply system is divided into cooking and dishwashing were shown to approximate the conventional unit model by setting the expected discharge flow rate for each system.