臺灣博碩士論文加值系統

研究背景及目的：烹飪不僅是室內空氣汙染的主要來源之一，長期暴露於烹飪汙染物也會對健康產生負面影響。而除了使用排油煙機能有效地移除烹飪汙染物之外，文獻回顧中發現，烹飪時打開窗戶也有助於廚房內外空氣流通，稀釋汙染物濃度。而現今對排油煙機的研究多集中於探討排氣流率以及造型的影響，尚缺乏針對家戶廚房中窗戶位置對廚房排油煙機效能的影響作研究評估。故本研究目的為使用經過驗證的計算流體動力學 (CFD) 方法，將二氧化碳作為烹飪汙染物的替代物，以探討窗戶位置與排氣量對家戶廚房內氣流流動特性、汙染物濃度分佈以及排油煙機捕集效率之影響。
方法：本研究將透過二氧化碳及溫度於穩態時所測量的數值與使用CFD模擬之結果作驗證比較。而符合驗證標準後的基本模型將用於模擬12種設定條件下，廚房內氣體流動結果。設定條件包含2種高度(1.2、2.4 m)及3種方向(前、側、後)的窗戶設置位置以及排油煙機的原始高低流率 (6.72、12.16 m3/min)，共12組案例。二氧化碳將作為室內空氣品質指標以計算排油煙機捕集效率以及探討每個模擬案例之間的差異性。
結果與討論：在模型驗證的部分，模擬值與實驗值之間的差異率在四個測量點處皆小於可接受標準 (10%)。而後在12個模擬案例中，在窗戶高度方面，觀察到當窗戶高度設置在2.4 m時，可以更有效地降低CO2濃度。探討3種窗戶方位的對抽油煙機效能的影響時，廚房中汙染物在開前窗時地濃度最低，且捕集效率皆高於80%，其次是後窗和側窗。另外，隨著排氣量從6.72 m3/min增加到 12.16 m3/min，所有窗口位置的捕集效率均可達到75%以上。
結論： 整體而言，改變窗戶與排油煙機的相對位置有助於改善廚房的整體通風，降低污染物濃度。透過本研究能更進一步提供在降低排氣流率與能源成本的情況下也能減少居民暴露於烹飪汙染物的方法。

Introduction: Studies have shown that cooking emissions would influence indoor air quality and cause adverse health effects on the human body. The kitchen hood is a common and effective intervention to remove harmful substances, meanwhile, previous studies showed that opening windows could also help with kitchen ventilation in pollutant removal. However, no studies have systematically examined the impacts of window positions on kitchen hood performance, and there is insufficient information on indoor airflow characteristics and pollutant distribution from makeup air through open windows. Therefore, the objective of this study was to use a validated computational fluid dynamic (CFD) approach with CO2 as a surrogate for cooking emissions to understand the impacts of exhaust flow rate and the window opening position on the flow characteristics, concentration distribution, and capture efficiency (CE) of the hood.
Method: We conducted four-point validation tests by comparing the numerical and experimental results based on CO2 concentration and temperature measurements under steady state conditions. The validated models were subsequently used in simulations to understand the effects of six different window opening positions and the two exhaust flow rates on exposure. CO2 was used as the IAQ indicator in order to understand the difference between each simulation cases.
Results and discussions: The results of the model validation were considered acceptable, the difference ratio between the simulation and experimental results were under 10% at four measure points. Among 12 simulation cases, we found that the CO2 concentration could be better reduced by having windows open at the higher location. Generally, the front windows were found to be more effective with CE >80%, followed by the back and the side windows, respectively. We also found that as the exhaust flow rate increased from 6.72 to 12.16 m3/min, CE reached >75% for all window positions, where the largest increase was 1.58 times for the lower side window.
Conclusion: In sum, changing the relative position of the window and the exhaust hood could help disperse the incoming airflow from the window, improve the kitchen's overall ventilation, and reduce contaminant concentration. Findings from this study provide important implications that when the architectural configuration was arranged correctly, the hood performance could be well improved to protect residents from exposure to cooking emissions, even under the low exhaust flow rate with reduced energy cost.

口試委員會審定書 i
致謝 ii
中文摘要 iii
ABSTRACT v
CONTENTS vii
LIST OF FIGURES ix
LIST OF TABLES x
Chapter 1. Introduction 1
Chapter 2. Materials and Methods 5
2.1. Study zone 5
2.2 Hood selection 7
2.3. Experimental procedure 8
2.4. Numerical method 10
2.4.1. Software 10
2.4.2. Governing Equations 11
2.5. Boundary conditions 13
2.6. Model validation 16
2.7. Simulation cases 17
Chapter 3. Results of Numerical Simulation 20
3.1. Grid independence test and model validation 20
3.2. Simulation cases 22
3.2.1. Distribution of the flow field by different exhaust flow rate 22
3.2.2. Distribution of the flow field by different window height 23
3.2.3. Distribution of the flow field by different window-wall locations 29
3.2.4. Capture Efficiency of the simulation cases 30
Chapter 4. Discussion 34
4.1. Distribution of the flow field in specific cases 34
4.2. Comparison of CE to other studies 35
4.3. Study strengths and limitations 37
Chapter 5. Conclusion 39
REFERENCE 40
APPENDIX 43

1. Klepeis, N.E., et al., The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. Journal of Exposure Analysis and Environmental Epidemiology, 2001. 11(3): p. 231-252.
2. Jones, A.P., Indoor air quality and health. Atmospheric Environment, 1999. 33(28): p. 4535-4564.
3. Zhao, Y.J. and B. Zhao, Emissions of air pollutants from Chinese cooking: A literature review. Building Simulation, 2018. 11(5): p. 977-995.
4. Abdullahi, K.L., J.M. Delgado-Saborit, and R.M. Harrison, Emissions and indoor concentrations of particulate matter and its specific chemical components from cooking: A review. Atmospheric Environment, 2013. 71: p. 260-294.
5. Chen, C., Y.J. Zhao, and B. Zhao, Emission Rates of Multiple Air Pollutants Generated from Chinese Residential Cooking. Environmental Science & Technology, 2018. 52(3): p. 1081-1087.
6. Ko, Y.C., et al., Chinese food cooking and lung cancer in women nonsmokers. American Journal of Epidemiology, 2000. 151(2): p. 140-147.
7. Belanger, K., et al., Association of indoor nitrogen dioxide exposure with respiratory symptoms in children with asthma. American Journal of Respiratory and Critical Care Medicine, 2006. 173(3): p. 297-303.
8. Hu, Y., J.S. Ji, and B. Zhao, Restrictions on indoor and outdoor NO2 emissions to reduce disease burden for pediatric asthma in China: A modeling study. Lancet Regional Health-Western Pacific, 2022. 24.
9. Chen, T.Y., et al., Impact of cooking oil fume exposure and fume extractor use on lung cancer risk in non-smoking Han Chinese women. Scientific Reports, 2020. 10(1).
10. Zhao, Y.J. and B. Zhao, Reducing human exposure to PM 2.5 generated while cooking typical Chinese cuisine. Building and Environment, 2020. 168.
11. Han, O., A.G. Li, and R. Kosonen, Hood performance and capture efficiency of kitchens: A review. Building and Environment, 2019. 161.
12. Dobbin, N.A., et al., The benefit of kitchen exhaust fan use after cooking - An experimental assessment. Building and Environment, 2018. 135: p. 286-296.
13. Singer, B.C., et al., Pollutant concentrations and emission rates from natural gas cooking burners without and with range hood exhaust in nine California homes. Building and Environment, 2017. 122: p. 215-229.
14. Sun, L., et al., Effect of venting range hood flow rate on size-resolved ultrafine particle concentrations from gas stove cooking. Aerosol Science and Technology, 2018. 52(12): p. 1370-1381.
15. Zhao, H.R., et al., Indoor air quality in new and renovated low-income apartments with mechanical ventilation and natural gas cooking in California. Indoor Air, 2021. 31(3): p. 717-729.
16. Rim, D., et al., Reduction of exposure to ultrafine particles by kitchen exhaust hoods: The effects of exhaust flow rates, particle size, and burner position. Science of the Total Environment, 2012. 432: p. 350-356.
17. Zhou, J. and C.N. Kim, Numerical Investigation of Indoor CO2 Concentration Distribution in an Apartment. Indoor and Built Environment, 2011. 20(1): p. 91-100.
18. Zhou, B., et al., Study on pollution control in residential kitchen based on the push-pull ventilation system. Building and Environment, 2016. 107: p. 99-112.
19. Chen, Z.L., J.J. Xin, and P.Y. Liu, Air quality and thermal comfort analysis of kitchen environment with CFD simulation and experimental calibration. Building and Environment, 2020. 172.
20. Le Hocine, A.E.B., S. Poncet, and H. Fellouah, CFD modeling of the CO2 capture by range hood in a full-scale kitchen. Building and Environment, 2020. 183.
21. Liu, Y., et al., Numerical investigation on the influence of natural make-up air in Chinese-style residential kitchen on indoor environment in a partitioned household. Sustainable Energy Technologies and Assessments, 2021. 46: p. 101244.
22. Xu, F. and Z. Gao, Transport and control of kitchen pollutants in Nanjing based on the Modelica multizone model. Journal of Building Performance Simulation, 2022. 15(1): p. 97-111.
23. Sun, L. and L.A. Wallace, Residential cooking and use of kitchen ventilation: The impact on exposure. Journal of the Air & Waste Management Association, 2021. 71(7): p. 830-843.
24. Wang, Y.B., H.X. Li, and G.H. Feng, Numerical study of the influence of ventilation modes on the distribution and deposition of particles generated from a specific cooking process in a residential kitchen. Indoor and Built Environment, 2021. 30(10): p. 1676-1692.
25. ASHRAE, Ventilation and indoor air quality in low-rise residential buildings, standard 62.2. 2010, American Society of Heating, Refrigerating and Air-conditioning Engineers: Atlanta, GA.
26. Zhao, Y.J., et al., The impact of various hood shapes, and side panel and exhaust duct arrangements, on the performance of typical Chinese style cooking hoods. Building Simulation, 2013. 6(2): p. 139-149.
27. Cui, S.Q., et al., CO2 tracer gas concentration decay method for measuring air change rate. Building and Environment, 2015. 84: p. 162-169.
28. Sobachkin, A. and G. Dumnov, Numerical Basis of CAD-Embedded CFD, in NAFEMS World Congress. 2014: Salzburg, Austria. p. 1-20.
29. Lam, C.K.G. and K. Bremhorst, A MODIFIED FORM OF THE K-EPSILON MODEL FOR PREDICTING WALL TURBULENCE. Journal of Fluids Engineering-Transactions of the Asme, 1981. 103(3): p. 456-460.
30. Patankar, S.V., Numerical Heat Transfer and Fluid Flow. 1980, Washington: Hemisphere Publishing Corporation.
31. Li, Y.G. and A. Delsante, Derivation of capture efficiency of kitchen range hoods in a confined space. Building and Environment, 1996. 31(5): p. 461-468.
32. Delp, W.W. and B.C. Singer, Performance Assessment of U.S. Residential Cooking Exhaust Hoods. Environmental Science & Technology, 2012. 46(11): p. 6167-6173.
33. Lunden, M.M., W.W. Delp, and B.C. Singer, Capture efficiency of cooking-related fine and ultrafine particles by residential exhaust hoods. Indoor Air, 2015. 25(1): p. 45-58.
34. Singer, B.C., et al., Performance of installed cooking exhaust devices. Indoor Air, 2012. 22(3): p. 224-234.
35. Gao, N.P., et al., The airborne transmission of infection between flats in high-rise residential buildings: Tracer gas simulation. Building and Environment, 2008. 43(11): p. 1805-1817.