Comparison of direct and indirect determinations of dynamic ventilation rate in a modern dairy free stall barn

作     者：Bing Zou Albert J.Heber Zhengxiang Shi Songhuai Du Yaomin Jin Teng Teeh Lim 

作者机构：College of Information and Electrical EngineeringChina Agricultural UniversityBeijing 100083 China Department of Agriculture and Biological EngineeringPurdue UniversityWest Lafayette 47907USA College of Water Sources and Civil EngineeringChina Agricultural UniversityBeijing 100083China Ministry of EnergyMines and Petroleum ResourcesVictoria V8W 9N3Canada College of AgricultureFood and Natural ResourcesUniversity of MissouriColumbia 65211USA 

出 版 物：《International Journal of Agricultural and Biological Engineering》 (国际农业与生物工程学报（英文）)

年 卷 期：2020年第13卷第2期

页      面：41-46页

核心收录：

学科分类：07[理学] 0701[理学-数学] 070101[理学-基础数学] 

基　　金：Agriculture Research System of China  (CARS-36) 

主　　题：dynamic ventilation rate modern dairy free stall barn carbon dioxide mass balance dairy cow direct and indirect determination comparison 

摘      要：Reliable estimation of the ventilation rate(VR)in intensive livestock buildings is necessary for studying building environmental control strategies and predicting indoor air quality and air *** direct air exchange measurements are time-consuming and expensive,it is environmentally inefficient to measure livestock building VR continuously in ***,indirect VR estimation methods have been widely used in modelling environmental control and air emissions,and also to measure airflow in the *** accuracy of indirect measurement methods needs to be evaluated by comparing with direct *** this study,the direct and indirect methods of determining hourly and daily mean VRs were applied to a mechanically-ventilated dairy free stall barn monitored by the 24-month National Air Emissions Monitoring *** direct method was used to continuously monitor fan rotational speeds,and differential static pressures,coupled with periodic in-situ fan performance assessments,to calculate the *** indirect method consisted of estimating the VR using CO2 concentration measurements and the CO2 mass balance *** average daily and hourly means(mean±SD)of directly measured barn ventilation rates for two years were(246±73)m3/s and(245±77)m3/s,*** average daily and hourly means(mean±SD)of barn ventilation rates estimated by the CO2 mass balance method were(287±93.4)m3/s and(287±118)m3/s,*** analyses showed a strong correlation between the indirect CO2 mass balance method and direct measurement methods(r=0.93 for daily means and r=0.85 for hourly means).