Numerical Simulation Investigation on Natural Gas Leakage under Different Kitchen Layouts in China

The safety of an open kitchen is a controversial topic in China. In this study, natural gas leakage and ventilation processes under an open kitchen layout and closed kitchen layout are simulated by CFD. The evolution of a hazardous gas cloud and the triggering behaviors of alarms are analyzed and discussed. For closing all windows in the leakage process, the state of the partition door is a major factor. A closed kitchen layout with a closing partition door performs best in confining a hazardous gas cloud. At this point, it is difficult for a hazardous gas cloud to appear in the living area. With the partition door open, the gas cloud develops rapidly. For opening windows in the leakage process, a large scale hazardous gas cloud is not able to form under all layouts. For alarm-triggering behaviors, a closed kitchen layout when closing the partition door also performs best. When opening the partition door, alarms cannot trigger stably under all layouts. For the ventilation process, hazardous gas cloud dissipation under an open kitchen layout is slightly faster than the closed kitchen layout. Under a weak convection effect, there is a transition stage which delays the time point for exhausting leaked gas. Based on the analysis, some recommendations for accident prevention are proposed. Residents should try to use closed kitchens and close partition doors when not cooking. If open kitchens are used, multiple alarms with lower trigger values should be installed. It is better to choose a ceiling type for gas alarms. The windows of the house are recommended to select two layers type. Higher layers can open during the ventilation process to accelerate the exhaust of leaked gas. These recommendations provide a reference for preventing fires and explosions.