DOI: 10.5061/dryad.kh18932h8
title: Numerical investigation for hazardous gas cloud form and dissipation behavior of hydrogen blended natural gas in a confined space

description: The safety of Hydrogen blended natural gas (HBNG) in confined space is an
 issue, especially for ventilation process. In this study, leakage and
 ventilation processes of low pressure HBNG with different hydrogen blended
 ratio(HBR) in confined space are simulated and validated by experiment
 based on similarity criteria. For leakage process, the leak direction and
 HBR does not significantly affect gas accumulation behavior. The required
 time for gas cloud to fill space decreases slightly with HBR rising and
 they generally show linear relationship. For ventilation process, the main
 influences on the leakage process are the total leakage mass and the
 ventilation conditions. The required time for hazardous gas cloud
 dissipate increases with total leakage mass and decreases with HBR. For
 different ventilation conditions, the ranking of required time to exhaust
 leaked gas is low &gt; center &gt; high &gt; mix. Through the
 analysis of pressure distribution, it is found time difference is produced
 by different airflow patterns. With the asymmetric layout, outside air
 rushes into the confined space from the high side and then flows out from
 the low side carrying the leaked HBNG. These findings inform the design of
 ventilation for HBNG utilization scenarios like restaurant facing the
 street.
description: This study was done using CFD software called fluent. All data
 were obtained from post-processing of the CFD simulation results. The
 software chosen for post-processing in this study was Tecplot. The
 physical variables in the study, except for the hazardous gas cloud
 volume, can be easily obtained under conditions of some understanding of
 post-processing. The hazardous gas cloud volume is the sum of the
 approximate grid volumes, and the method of obtaining it is explained in
 detail in the manuscript.
description: # Numerical investigation for hazardous gas cloud form and dissipation
 behavior of hydrogen blended natural gas in a confined space
 [https://doi.org/10.5061/dryad.kh18932h8](https://doi.org/10.5061/dryad.kh18932h8) ## Description of the data and file structure 1 The uploaded data are labeled at the file corresponding to the location in the manuscript. 2 Note that some of the data is on the second and third pages of the xls file 3 For units of data, please refer to the notation in the manuscript ### Files and variables #### File: fig6.xlsx **Description:** Comparison of numerical simulation and experiment results. The first column is the leakage time. The second column is the experiment value and the third column is the silumation value.  ##### Variables * Leakage time-VOL% #### File: fig7.xlsx **Description:** CH4 volume fraction variation at monitoring point. The first column is the leakage time. The number in the first row refers to the number of grid cells. ##### Variables * Leakage time-VOL% #### File: fig9.xlsx **Description:** Hazardous gas cloud volume variation under different leakage degree. The first column is the leakage time.  ##### Variables * Leakage time-gas cloud volume #### File: fig11.xlsx **Description:** Required time variation under different leakage degree and leakage diameter. ##### Variables * Leakage degree-required time #### File: fig12.xlsx **Description:** Velocity distribution in Y direction. The first column is the height in Y direction. The second column is the velocity value. ##### Variables * Height-Velocity #### File: fig14.xlsx **Description:** Required time to reach 150 m3 ##### Variables * HBR-required time #### File: fig17.xlsx **Description:** HBNG volume fraction variation on monitor points ##### Variables * Leakage time-Volume fraction #### File: fig18.xlsx **Description:** Uniformity index variation from 1680 s to 1920 s. The difinition of uniformity index is shown in the paper (eq:3.2). ##### Variables * Leakage time-Uniformity index #### File: fig21.xlsx **Description:** Required time for different total leakage mass ##### Variables * Layout-required time #### File: fig22-1.xlsx **Description:** Hazardous gas volume variation under different ventilation conditions (Part 1) ##### Variables * Leakage time-gas cloud volume #### File: fig23.a.xlsx **Description:** Required time variation under different conditions ##### Variables * Layout-required time #### File: fig22-2.xlsx **Description:**  Hazardous gas volume variation under different ventilation conditions (Part 2) ##### Variables * Leakage time-gas cloud volume #### File: fig23.b.xlsx **Description:** Required time variation under different conditions ##### Variables * HBR-required time #### File: fig26.xlsx **Description:** Mass flow constitutions under different ventilation conditions ##### Variables * Mass flowrate-ventilation condition #### File: fig20.xlsx **Description:** Hazardous gas cloud volume variation under different total leakage mass ##### Variables * Ventilation time-gas cloud volume #### File: fig13.xlsx **Description:** Hazardous gas cloud volume variation under HBRs ##### Variables * Leakage time-gas cloud volume ## Code/software ### Apache OpenOffice and any free excel viewer can view our data. The latest package can download here. [Apache OpenOffice - 开放免费的文字处理软件](https://www.openoffice.org/zh-cn/)