Modelling and reducing gas emissions from naturally ventilated livestock buildings

Livestock buildings are identified to be a major source of ammonia emissions. About 30% of the total ammonia emission within livestock sectors is from naturally ventilated dairy cattle buildings. The main objectives of this study are to predict emissions from naturally ventilated dairy cattle buildings and to establish a systematic approach to curtail the emissions. Gas concentrations were measured inside two dairy cattle buildings in mid-Jutland, Denmark. CO2 balance method was thus applied to estimate ventilation and emission rates. Computational fluid dynamics (CFD) was used to find the optimum gas sampling positions for outlet CO2 concentration. The gas sampling positions should be located adjacent to the openings or even in the openings. The NH3 emission rates varied from 32 to77 g HPU-1 d-1 in building 1 and varied from 18 to30 g HPU-1 d-1 in building 2. Scale model experiment showed that partial pit ventilation was able to remove a large portion of polluted gases under the slatted floor. In the full scale simulations, a pit exhaust with a capacity of 37.3 m3 h-1 HPU-1 may reduce ammonia emission only by 3.16% compared with the case without pit ventilation. When the external wind was decreased to 1.4 m s-1 and the sidewall opening area were reduced to half, such a pit ventilation capacity can reduce ammonia emission by 85.2%. The utilization of pit ventilation system must be integrated with the control of the natural ventilation rates of the building.

[1]  B. Launder,et al.  The numerical computation of turbulent flows , 1990 .

[2]  Guoqiang Zhang,et al.  Effects of a partial pit ventilation system on indoor air quality and ammonia emission from a fattening pig room , 2010 .

[3]  Bjarne Bjerg,et al.  Porous media as boundary condition for air inlet, slatted floor and animal occupied zone in numerical simulation of airflow in a pig unit. , 2008 .

[4]  Ji-Qin Ni,et al.  Airflow and concentration characterisation and ammonia mass transfer modelling in wind tunnel studies , 2010 .

[5]  T. Stathopoulos,et al.  CFD simulation of the atmospheric boundary layer: wall function problems , 2007 .

[6]  Kit Ming Lam,et al.  Recent progress in CFD modelling of wind field and pollutant transport in street canyons , 2006 .

[7]  Thierry Boulard,et al.  Numerical simulation of the airflow and temperature distribution in a tunnel greenhouse equipped with insect-proof screen in the openings , 2002 .

[8]  Guoqiang Zhang,et al.  An assessment of a partial pit ventilation system to reduce emission under slatted floor - Part 1: Scale model study , 2012 .

[9]  Bjarne Bjerg,et al.  NUMERICAL SIMULATION OF A PIT EXHAUSTS SYSTEM FOR REDUCTION OF AMMONIA EMISSION FROM A NATURALLY VENTILATED CATTLE BUILDING , 2010 .

[10]  Matthias Ketzel,et al.  Intercomparison of Numerical Urban Dispersion Models – Part I: Street Canyon and Single Building Configurations , 2002 .

[11]  D. Clark,et al.  Measurement of night sky emissivity in determining radiant cooling from cool storage roofs and roof ponds , 1995 .

[12]  H. Park,et al.  PARAMETERIZATION OF THE POLLUTANT TRANSPORT AND DISPERSION IN URBAN STREET CANYONS , 1994 .

[13]  H. Müller,et al.  Emissions of ammonia and methane from a livestock building natural cross ventilation , 2011 .

[14]  F. Menter.  Two-equation eddy-viscosity turbulence models for engineering applications , 1994 .

[15]  Dennis Y.C. Leung,et al.  On the prediction of air and pollutant exchange rates in street canyons of different aspect ratios using large-eddy simulation , 2005 .

[16]  Liu,et al.  A computational fluid dynamics study of tadpole swimming , 1996, The Journal of experimental biology.

[17]  Jong-Jin Baik,et al.  A Numerical Study of Flow and Pollutant Dispersion Characteristics in Urban Street Canyons , 1999 .

[18]  Gordon M. Bragg,et al.  Distribution of ventilation air— Measuremebt and spectral analysis by microcomputer , 1988 .

[19]  M. Sherman.  Tracer-gas techniques for measuring ventilation in a single zone , 1990 .

[20]  Robert N. Meroney,et al.  Concentration and flow distributions in urban street canyons: wind tunnel and computational data , 2003 .

[21]  D. Olivari,et al.  Numerical and experimental modelling of pollutant dispersion in a street canyon , 2002 .

[22]  Guoqiang Zhang,et al.  Scale model experiments to determine the effects of internal airflow and floor design on gaseous emissions from animal houses , 2008 .

[23]  John G. Bartzis,et al.  Numerical investigation of the pollution dispersion in an urban street canyon , 2006, Environ. Model. Softw..

[24]  Sandrine Anquetin,et al.  Pollutant dispersion and thermal effects in urban street canyons , 1996 .

[25]  Jong-Jin Baik,et al.  Effects of inflow turbulence intensity on flow and pollutant dispersion in an urban street canyon , 2003 .

[26]  Guoqiang Zhang,et al.  Experimental and Numerical Study on Effects of Airflow and Aqueous Ammonium Solution Temperature on Ammonia Mass Transfer Coefficient , 2010, Journal of the Air & Waste Management Association.

[27]  Peter V. Nielsen,et al.  An assessment of a partial pit ventilation system to reduce emission under slatted floor - Part 2: Feasibility of CFD prediction using RANS turbulence models , 2012 .

[28]  G. T. Johnson,et al.  Urban wind flows: wind tunnel and numerical simulations—a preliminary comparison , 1998 .

[29]  Eberhard Hartung,et al.  Ammonia emissions and emission factors of naturally ventilated dairy housing with solid floors and an outdoor exercise area in Switzerland , 2012 .

[30]  Da-Wen Sun,et al.  A computational fluid dynamics study of air mixing in a naturally ventilated livestock building with different porous eave opening conditions , 2010 .

[31]  Guoqiang Zhang,et al.  Emission effects of three different ventilation control strategies—A scale model study , 2008 .

[32]  Guoqiang Zhang,et al.  CFD Investigation of a Partly Pit Ventilation System as Method to Reduce Ammonia Emission from Pig Production Units , 2008 .

[33]  Guoqiang Zhang,et al.  Modeling Jet Drop Distances for Control of a Nonisothermal, Flap-adjusted Ventilation Jet , 1996 .

[34]  Theo Demmers,et al.  First experiences with methods to measure ammonia emissions from naturally ventilated cattle buildings in the U.K. , 1998 .

[35]  Peter V. Nielsen,et al.  Evaluation of methods for determining air exchange rate in a naturally ventilated dairy cattle building with large openings using computational fluid dynamics (CFD) , 2012 .

[36]  Chun-Ho Liu,et al.  Large-Eddy Simulation of Flow and Scalar Transport in a Modeled Street Canyon , 2002 .

[37]  Theo Demmers,et al.  SE—Structure and Environment: Validation of Ventilation Rate Measurement Methods and the Ammonia Emission from Naturally Ventilated Dairy and Beef Buildings in the United Kingdom , 2001 .

[38]  Efisio Solazzo,et al.  Improved parameterisation for the numerical modelling of air pollution within an urban street canyon , 2009, Environ. Model. Softw..

[39]  Jong-Jin Baik,et al.  On the escape of pollutants from urban street canyons , 2002 .

[40]  David D. Apsley,et al.  Flow and dispersion over topography: A comparison between numerical and laboratory data for two-dimensional flows , 1997 .

[41]  Jan Willem Erisman,et al.  Ammonia emission from dairy cow buildings: a review of measurement techniques, influencing factors and possibilities for reduction , 1998 .

[42]  Guoqiang Zhang,et al.  Ammonia and methane emissions from two naturally ventilated dairy cattle buildings and the influence of climatic factors on ammonia emissions , 2012 .

[43]  Baoming Li,et al.  Emission of Ammonia and Other Contaminant Gases from Naturally Ventilated Dairy Cattle Buildings , 2005 .

[44]  J. Hartung,et al.  A Survey of Ventilation Rates in Livestock Buildings in Northern Europe , 1998 .

[45]  Jon Wieringa,et al.  Updating the Davenport roughness classification , 1992 .

[46]  K. Cooper,et al.  A Thermal Balance Model for Livestock Buildings for use in Climate Change Studies , 1998 .

[47]  Zhao Zhang,et al.  Evaluation of Various Turbulence Models in Predicting Airflow and 1 Turbulence in Enclosed Environments by CFD : Part-1 : 2 Summary of Prevalent Turbulence Models 3 4 , 2007 .

[48]  B. E. Launder.  The Numerical computational of turbulent flows , 1974 .

[49]  Harold M. Keener,et al.  Development and Validation of 3-D CFD Models to Simulate Airflow and Ammonia Distribution in a High-Rise Hog Building during Summer and Winter Conditions , 2004 .

[50]  H. F. A. van den Weghe,et al.  Ventilation Rates and Gaseous Emissions from Naturally Ventilated Dairy Houses , 2003 .

[51]  K. Pericleous,et al.  Modelling air quality in street canyons : a review , 2003 .

[52]  Kang-Shin Chen,et al.  Measurements and three-dimensional modeling of air pollutant dispersion in an Urban Street Canyon , 2004 .

[53]  Mitsuru Arai,et al.  A two-dimensional air quality model in an urban street canyon: evaluation and sensitivity analysis , 2000 .

[54]  Shaojin Wang,et al.  PA—Precision Agriculture: Convective and Ventilation Transfers in Greenhouses, Part 1: the Greenhouse considered as a Perfectly Stirred Tank , 2002 .

[55]  Theo Demmers,et al.  Assessment of Techniques for Measuring the Ventilation Rate, using an Experimental Building Section , 2000 .

[56]  Guoqiang Zhang,et al.  Assessing effect of wind tunnel sizes on air velocity and concentration boundary layers and on ammonia emission estimation using computational fluid dynamics (CFD) , 2011 .

[57]  C. R. Braam,et al.  Ammonia Emission from a Double-Sloped Solid Floor in a Cubicle House for Dairy Cows , 1997 .

[58]  Da-Wen Sun,et al.  Assessing the ventilation effectiveness of naturally ventilated livestock buildings under wind dominated conditions using computational fluid dynamics , 2009 .