LNG车用瓶培训(查特-1).ppt

瓶内压力太低 经济调压阀回路未完全关闭或调校设定值太低 饱和压力太低 充液站饱和压力太低 液体未达到饱和状态 泄漏 经济调压阀的校验 进入到发动机内的燃料温度太低 汽化器性能差 冷却水循环不畅 汽化器内有气体 使用流量过大 液位表/压力表失效诊断 线路接错 接头 松动 腐蚀 水污染 传感器线路断开 压力传感器失效 液位传感器 进水 未校验好 液位表失效诊断 液位表维修包包括： 电容式液位计 电线端子 更换液位显示仪 重新校验液位计 更换液位变送器 谢谢! * * * * Checking for leaks is very important with any kind of fuel as is the case for natural gas. Leak checks should be done periodically, whenever the vehicle is in for service i.e.. oil changes, etc. Leaks can show up in several ways: on-board methane alarm, loss of fuel pressure, excess frost, bubbling, whisping noise, etc. Leaks can be found in several ways. An initial visual and audible inspection of the system can be effective by looking for the frost spots and/or bubbling and listening for a whisping type noise depending on how bad the leak is. An effective way to enhance the visual method is to use a soap bubble solution, such as snoop to help locate the source of the leak by spraying it on all of the lines and fittings, and then watching for it to start to bubble which will occur at the leak. Another method to locate a leak is to use a handheld methane detector. Follow the manufacturer’s instructions for proper usage. It is important to adjust and monitor the sensitivity because slight traces of methane can be found in the air. Landfill sites and farms with cattle are likely areas to find significant amounts of methane in the air, which will move with the wind and can create havoc when trying to locate methane leaks. On-board methane detectors may also sense a leak, and depending on the detection system, may even tell the zone that it is from on a particular vehicle. Another symptom that fuel leaks may cause might be poor fuel mileage due to the wasted fuel. * There are several areas and components where leaks can occur from. Compression and pipe threaded fittings are used throughout the LNG system and will probably be the most common source of leaks. The BNC nipple and elbow fall are pipe threaded fittings although th