Department of Civil Engineering, The University of Texas at Arlington, Arlington, TX, 76019, United States.
The Energy Institute, Colorado State University, Fort Collins, CO, 80523, United States.
Environ Pollut. 2022 Nov 1;312:120027. doi: 10.1016/j.envpol.2022.120027. Epub 2022 Aug 24.
The 2015 Paris agreement aims to cut greenhouse gas emissions and keep global temperature rise below 2 °C above pre-industrial levels. Reducing CH emissions from leaking pipelines presents a relatively achievable objective. While walking and driving surveys are commonly used to detect leaks, the detection probability (DP) is poorly characterized. This study aims to investigate how leak rates, survey distance and speed, and atmospheric conditions affect the DP in controlled belowground conditions with release rates of 0.5-8.5 g min. Results show that DP is highly influenced by survey speed, atmospheric stability, and wind speed. The average DP in Pasquill-Gifford stability (PG) class A is 85% at a low survey speed (2-11 mph) and decreases to 68%, 63%, 65%, and 60% in PGSC B/C, D, E/F, and G respectively. It is generally less than 25% at a high survey speed (22-34 mph), regardless of stability conditions and leak rates. Using the measurement data, a validated DP model was further constructed and showed good performance (R: 0.76). The options of modeled favorable weather conditions (i.e., PG stability class and wind speed) to have a high DP (e.g., >50%) are rapidly decreased with the increase in survey speed. Walking survey is applicable over a wider range of weather conditions, including PG stability class A to E/F and calm to medium winds (0-5 m s). A driving survey at a low speed (11 mph) can only be conducted under calm to low wind speed conditions (0-3 m s) to have an equivalent DP to a walking survey. Only calm wind conditions in PG A (0-1 m s) are appropriate for a high driving speed (34 mph). These findings showed that driving survey providers need to optimize the survey schemes to achieve a DP equivalence to the traditional walking survey.
2015 年《巴黎协定》旨在减少温室气体排放，将全球气温上升幅度控制在工业化前水平以上 2°C 以内。减少管道泄漏产生的 CH4 排放是一个相对可实现的目标。虽然行走和驾驶调查通常用于检测泄漏，但检测概率（DP）的描述很差。本研究旨在调查在受控地下条件下，以 0.5-8.5g min 的释放率下，泄漏率、调查距离和速度以及大气条件如何影响 DP。结果表明，DP 受到调查速度、大气稳定性和风速的高度影响。在低调查速度（2-11 英里/小时）下，帕斯奎尔-吉福德稳定（PG）等级 A 的平均 DP 为 85%，而在 PGSC B/C、D、E/F 和 G 中分别下降至 68%、63%、65%和 60%。无论稳定条件和泄漏率如何，在高调查速度（22-34 英里/小时）下，DP 通常小于 25%。使用测量数据，进一步构建并验证了 DP 模型，表明其具有良好的性能（R：0.76）。在高 DP（例如>50%）的有利天气条件（即 PG 稳定性等级和风速）的选择随着调查速度的增加而迅速减少。行走调查适用于更广泛的天气条件，包括 PG 稳定性等级 A 到 E/F 和静风到中等风（0-5 m s）。低速（11 英里/小时）的驾驶调查只能在静风到低风速条件（0-3 m s）下进行，以获得与行走调查等效的 DP。只有在 PG A（0-1 m s）中，静风条件才适合高速驾驶（34 英里/小时）。这些发现表明，驾驶调查提供者需要优化调查方案，以达到与传统行走调查等效的 DP。
