在屋顶安装的10吨成套装置上测量了烟气和建筑物排气的再吸入，以确定排气的再吸入百分比与分离距离、气流方向和风速之间存在的关系。通过测量烟气中的CO2浓度，并将其与新鲜空气入口中的CO2浓度进行比较，确定夹带的烟气量。在省煤器模式下运行时，排气气流中的CO2浓度达到峰值，并与进气中的CO2浓度进行比较。该装置的燃气炉排放的烟气稀释率数据是在该装置以三种不同的烟气排气配置运行时获得的:一个高的垂直排气口、一个短的垂直排气口和一个向下的排气口。测量的最低稀释率为1284（高烟囱）、368（短烟囱）和290（向下烟囱）。羽流稀释预测使用1997年ASHRAE《建筑废气大气扩散基本原理》中给出的解析表达式，并使用计算流体动力学（CFD）分析。 预测结果非常一致，两人都预测稀释度比该装置的测量值高出约50%。这两种方法都对夹带烟气的稀释率进行了保守估计。在省煤器模式下，机组在不同的排气和进气水平下运行。测得的最小稀释比为9。在这种情况下，ASHRAE基本原理分析表达式不足以预测最小稀释率。估计值与测量值相差5倍。CFD分析预测的最小稀释比是除一种情况外所有情况下测量值的2到5倍。人们认为，排放建筑空气的方法是预测结果与数据不一致的原因。增加排气口的高度可以显著增加夹带烟气的稀释度。为了增加建筑物排气的稀释度，建议减少对建筑物排气的限制，以便以高速将排气引离装置。 单元:双引文:研讨会，ASHRAE交易，第108卷，第。2.

The reentrainment of flue gas and building air exhaust was measured on a roof-mounted, 10-ton packaged unit to identify the relationships that exist between percent reentrainment of exhaust air and separation distances, direction of airflow, and wind speed. The amount of entrained flue gas was determined by measuring the concentration of CO2in the flue gas exhaust and comparing it with the concentration of CO2in the fresh air intake. When operating in the economizer mode, the exhaust airstream was spiked with CO2and compared with the intake CO2concentration.Dilution ratio data for flue gases emitted by the unit’s gas furnace were obtained with the unit operating with three different flue gas exhaust configurations:a tall vertical vent, a short vertical vent, and a downward-facing exhaust.The minimum dilution ratios measured were 1284 for the tall stack, 368 for the short stack,and 290 for the downward-facing stack. Plume dilution predictions were made using the analytical expressions presented in the 1997 ASHRAE Fundamentals for atmospheric dispersion of building exhaust and using computational fluid dynamic (CFD)analysis. The predictions were in good agreement, and both predicted approximately 50% greater dilution than measured for this unit. Both methods provided a conservative estimate of the dilution ratio of entrained flue gases.In the economizer mode, the unit was operated at different levels of exhaust and intake air. The minimum dilution ratio measured was 9. The ASHRAE Fundamentals analytical expressions were not adequate to predict the minimum dilution ratio in this case. The estimates differed from the measurements by a factor of 5. The minimum dilution ratio predicted by the CFD analysis was two to five times higher than the measurements for all but one case. The method of exhausting the building air is believed to be the reason for the poor agreement between the predictions and the data.Increasing the height of the exhaust vent was shown to significantly increase the dilution of entrained flue gases. To increase the dilution of building air exhaust, it is recommended that the restrictions to the building air exhaust be reduced so the exhaust air can be directed away from the unit at high velocity.Units: Dual