沼气发电机组气源系统故障诊断全记录：从甲烷含量到管路气密性的深度解析

　　Full record of fault diagnosis of gas source system for biogas generator set: in-depth analysis from methane content to pipeline airtightness

　　在沼气发电系统的日常运行中，偶尔会遇到这样一种令人困惑的情况：黑膜沼气池内的沼气储量充足，压力表显示正常，但与之相连的沼气发电机组却无法启动或运行。面对这种 “有气无用” 的困境，技术人员的首要任务就是进行系统性的故障排查。根据大量实践经验，此类问题的根源绝大多数指向气源系统，具体可归纳为三大类：甲烷含量不达标、沼气管路堵塞以及管路气密性失效。本文将对这三类故障的诊断方法进行详细解析。

　　In the daily operation of biogas power generation systems, there is occasionally a confusing situation where the biogas storage in the black film biogas digester is sufficient and the pressure gauge displays normally, but the connected biogas generator set cannot start or operate. Faced with the dilemma of 'having energy but no use', the primary task of technicians is to conduct systematic troubleshooting. Based on extensive practical experience, the root cause of such problems mostly lies in the gas source system, which can be classified into three categories: inadequate methane content, blockage of biogas pipelines, and failure of pipeline airtightness. This article will provide a detailed analysis of the diagnostic methods for these three types of faults.

　　一、甲烷含量不足：燃烧的 “能量源” 不够

　　1、 Insufficient methane content: insufficient energy source for combustion

　　沼气发电机组的启动和稳定运行，依赖于沼气中甲烷（CH?）的含量维持在一个特定范围内，通常要求在 50% 以上。如果甲烷含量过低，即使沼气量再大，也无法满足发动机的点火和做功需求。

　　The start-up and stable operation of biogas generators rely on maintaining a specific range of methane (CH4) content in the biogas, usually requiring at least 50%. If the methane content is too low, even if the amount of biogas is large, it cannot meet the ignition and power requirements of the engine.

　　排查方法：最直接有效的方式是使用便携式气体分析仪，对进入发动机前的沼气进行实时成分检测。如果检测结果显示甲烷含量低于标准值，则需要追溯至沼气池的发酵工艺。可能的原因包括：发酵原料的碳氮比失衡、发酵温度过低导致产甲烷菌活性不足、或者发酵池出现酸化现象，抑制了甲烷的产生。解决此类问题需要调整进料配方、改善发酵环境或对发酵池进行必要的维护。

　　Troubleshooting method: The most direct and effective way is to use a portable gas analyzer to perform real-time component detection on the biogas before entering the engine. If the test results show that the methane content is lower than the standard value, it is necessary to trace back to the fermentation process of the biogas digester. Possible reasons include: an imbalance in the carbon to nitrogen ratio of the fermentation raw materials, insufficient activity of methane producing bacteria due to low fermentation temperature, or acidification in the fermentation tank, which inhibits methane production. To solve such problems, it is necessary to adjust the feed formula, improve the fermentation environment, or perform necessary maintenance on the fermentation tank.

　　二、沼气管路堵塞：气体流通的 “肠梗阻”

　　2、 Blockage of biogas pipeline: "intestinal obstruction" of gas circulation

　　从沼气池到发动机的输送管路，如同人体的血管，一旦发生堵塞，沼气便无法顺畅到达。堵塞物可能是发酵过程中产生的冷凝水、污泥杂质，或是管路安装时残留的异物。

　　The pipeline from the biogas digester to the engine, like the blood vessels of the human body, once blocked, the biogas cannot reach smoothly. Blockages may be condensation water, sludge impurities generated during the fermentation process, or foreign objects remaining during pipeline installation.

　　排查方法：首先检查管路中的各个阀门是否处于全开状态。随后，观察管路中的压力表读数，若在开启阀门后，压力表数值没有变化或变化极小，说明管路可能存在堵塞。技术人员需要分段检查管路，重点排查弯头、阀门、过滤器等易产生堵塞的部位。可以通过拆卸管路分段吹气，或使用高压气体反向吹扫的方式，清除堵塞物。安装高效的沼气过滤器，并定期清理，是预防此类故障的关键。

　　Troubleshooting method: First, check if all valves in the pipeline are fully open. Subsequently, observe the pressure gauge reading in the pipeline. If there is no or minimal change in the pressure gauge value after opening the valve, it indicates that there may be a blockage in the pipeline. Technicians need to inspect the pipeline in sections, with a focus on identifying areas such as bends, valves, and filters that are prone to blockage. Blockages can be removed by disassembling the pipeline and blowing air in sections, or by using high-pressure gas to blow in the opposite direction. Installing efficient biogas filters and regularly cleaning them are key to preventing such malfunctions.

　　三、管路气密性失效：系统的 “隐形漏洞”

　　3、 Pipeline airtightness failure: the "hidden loophole" of the system

　　如果说堵塞是 “不通”，那么气密性失效就是 “漏气”。沼气管路在运行过程中，可能因接口松动、管道老化开裂或安装不当等原因出现破损。当管路内部形成负压时，外界的空气会被吸入，与沼气混合。

　　If blockage is considered 'not accessible', then the failure of airtightness is referred to as' air leakage '. During the operation of biogas pipelines, damage may occur due to loose interfaces, aging and cracking of pipelines, or improper installation. When negative pressure is formed inside the pipeline, external air will be sucked in and mixed with biogas.

　　排查方法：空气的进入会稀释沼气中的甲烷浓度，破坏其空燃比，导致发动机无法点燃。检查气密性的方法包括：对整个管路系统进行压力测试，观察压力是否能稳定保持；或在管路的各个接口、焊缝处涂抹肥皂水，若有气泡产生，即表明存在泄漏点。对于发现的泄漏点，需要及时进行紧固或更换部件处理，确保整个气源系统的密闭性。

　　Troubleshooting method: The entry of air will dilute the methane concentration in biogas, disrupt its air-fuel ratio, and cause the engine to fail to ignite. The method of checking air tightness includes: conducting pressure tests on the entire pipeline system to observe whether the pressure can be stably maintained; Or apply soapy water to various interfaces and welds of the pipeline. If bubbles are generated, it indicates the presence of leakage points. For discovered leakage points, it is necessary to promptly tighten or replace components to ensure the airtightness of the entire gas source system.

　　综上所述，当沼气发电机组出现 “有气不工作” 的故障时，技术人员应遵循 “先易后难、分段排查” 的原则，从甲烷含量、管路堵塞和管路气密性这三个核心环节入手，逐一进行检测和排除。通过科学、细致的诊断，不仅能快速解决当前问题，更能为系统的长期稳定运行提供保障。

　　In summary, when a biogas generator unit experiences a malfunction of "not working with gas", technicians should follow the principle of "easy first, difficult later, and segmented troubleshooting", starting from the three core links of methane content, pipeline blockage, and pipeline airtightness, and conducting testing and elimination one by one. Through scientific and meticulous diagnosis, not only can current problems be quickly solved, but it can also provide guarantees for the long-term stable operation of the system.