管道燃气自闭阀使用前后性能变化研究

Study on Performance Change of Pipeline Gas Automatic Shut-off Valve before and after Use

结合管道燃气自闭阀在北京市的应用情况,以使用5 a后的自闭阀为样本,根据产品标准制定测试实验方案,对样本的性能进行测试,并分析原因。研究结果表明:通过5 a的使用情况跟踪,自闭阀产品的安全功能符合预期,尤其是过流自动关闭与欠压自动关闭功能在实际应用中得到了验证。自闭阀使用5 a后,产品的内、外气密性能够符合现行行业标准CJ/T 447—2014《管道燃气自闭阀》的要求。过流自动关闭性能没有明显的变化,自闭阀能够对胶管脱落、破裂导致燃气快速泄漏事故起到防护作用。超压自动关闭压力的均值变化率不大,但离散度增加,超压自动关闭性能降低,增加误关闭的风险。欠压自动关闭压力的均值变化率出现较大负偏移,使用后离散度也较大,欠压自动关闭性能降低,增加了灶具产生回火的概率。厨房环境中的电化学腐蚀、油烟、灰尘对自闭阀的性能影响不大,自闭阀主要零部件尺寸结构没有明显变化,磁铁性能没有明显衰退。某样本驱动元件膜片回弹性下降是自闭阀欠压自动关闭性能下降的主要因素,建议对自闭阀膜片材料进行改良,提高膜片回弹性。某样本上提杆超过正常行程引起膜片故障变形,造成上提杆无法下落复位,建议提高上提杆行程精度或对复位结构进行改进。

Combined with the application of pipeline gas automatic shut-off valve in Beijing,taking the automatic shut-off valve used for 5 years as the sample,the test scheme is formulated according to the product standard,the performance of the sample is tested,and the reasons are analyzed. The research results show that by tracking the use of 5 years,the safety function of the automatic shut-off valve product is in line with the expectation,especially the overflowing automatic shut-off and under-pressure automatic shut-off functions have been verified in practical applications.When the automatic shut-off valve is used for 5 years,the internal and external tightness of the product can meet the requirements of the current industry standard Automatic Shut-off Valve for Pipeline Gas( CJ/T 447 –2014). There is no obvious change in the overflowing automatic shut-off performance,and the automatic shutoff valve can protect the hose from falling off and breaking resulting in the rapid leakage of gas. The average change rate of the over-pressure automatic shutoff pressure is not large,but the dispersion increases,and the over-pressure automatic shut-off performance reduces,which increases the risk of false shut-off. The average change rate of the under-pressure automatic shut-off pressure has a large negative deviation,and the dispersion is also larger after use,so the under-pressure automatic shut-off performance reduces,which increases the probability of flash back of gas cooking appliance. The electrochemical corrosion,oil smoke and dust in the kitchen environment have little effect on the performance of the automatic shut-off valve,the size and structure of the main parts of the automatic shut-off valve have no obvious change,and the performance of the magnet has no obvious decline. The decrease of the resilience of diaphragm of a sample driving element is the main factor of the decrease of automatic shut-off performance. It is suggested that the diaphragm material of automatic shut-off valve should be improved to improve the resilience of diaphragm. The fault deformation of the diaphragm caused by the lifting rod exceeding the normal stroke in a sample causes the lifting rod to be unable to fall and reset. It is suggested to improve the stroke accuracy of the lifting rod or to improve the reset structure.