关键词: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">固定式, 可燃气体, 有毒气体, 检测器, 泄漏, 扩散

Abstract: This article briefly describes the commonly used gas diffusion models and analyzes the engineering design standards and specifications of gas detectors. Using PHAST software, taking liquefied petroleum gas (LPG) and H2S as examples, the leakage diffusion is calculated, and the relationship between the concentration of combustible gases and toxic gases and time and space is obtained, determining the effective spatial area for setting fixed-point combustible gas detectors and fixed-point H2S detectors. Under the selected medium parameters, leakage scenarios, and meteorological conditions, the horizontal distance between the fixed-point combustible gas detector and the release source should not exceed 8.4m; the horizontal distance between the fixed-point H2S detector and the release source should not exceed 5.4m; if it is necessary to detect the first-level alarm value (volume fraction 0.005‰) within 4m from the H2S release source, then a fixed-point H2S detector should be set when the initial volume fraction of H2S in the leaked gas reaches 0.75‰ or above.

Key words: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">fixed, combustible gas, toxic gas, detector, leakage, diffusion