6.1 变压器油中溶解气体的检测 6.1 Detection of gases dissolved in transformer oil,6.1.1绝缘故障与油中溶解气体 6.1.1 Insulation fault and dissolved gas in oil 6.1.2油中气体分析与故障诊断 6.1.1 Oil gas analysis and fault diagnosis 6.1.3油中溶解气体的在线监测 6.1.3 On-line monitoring of dissolved gases in oil,变压器的绝缘发生故障时产生故障气体，故障气体部分溶解于油中，部分进入气体继电器。 Fault gas is generated by transformer insulation failures. Then the gas dissolves in oil, some of which enters the relays.,6.1.1 绝缘故障与油中溶解气体 6.1.1 Insulation fault and dissolved gas in oil,变压器绝缘故障主要分为三类：热故障、电故障及其绝缘受潮，故障不同时，油中溶解的故障气体成分不同，因此可以通过分析油中溶解气体的成分来判断变压器存在的绝缘故障。,Transformer insulation faults can be divided into three categories： heat failure, electrical failure, and humidified insulation. The components of dissolved gas in oil are different when the failure mechanisms are different. so we can judge the type of insulation failure by dissolved gas analysis in oil.,过热故障 Overheating fault,变压器过热故障是最常见的故障，空载损耗、负载损耗和杂散损耗等转化为热量，当产生的热量和散出的热量平衡时，温度达到稳定状态。当发热量大于预期值，而散热量小于预期值时，就发生过热现象。,The overheating fault of transformer is the most familiar fault, no-load loss, load loss and stray loss and so on transforming into heat. when the heat produced and out balanced, the temperature reaches steady .When the heat value is higher than expected, and heat dissipation is less than expected, overheating is occurrence.,放电故障是由于电应力作用而造成绝缘裂化，按能量密度不同可以分成电弧放电、火花放电和局部放电等。,Discharge fault is due to stress causing insulation cracking. According to the different energy density it can be divided into arc discharge ,spark discharge and partial discharge.,2. 放电故障 Discharge fault,当变压器内部进水受潮时，油中的水分和含湿气的杂质容易形成“水桥”，导致局部放电而产生H2。水分在电场作用下的电解以及水和铁的化学反应均可产生大量的H2 。所以受潮设备中， H2在氢烃总量中占比例更高。,3. 绝缘受潮 Humidified insulation,When the transformer internal enters water it becomes moisture, water in the oil . The moisture impurities content can easily form “Water Bridge”, which causes partial discharge and produces H2. Moisture electrolysis under the electric field and chemical reactions between moisture and iron which produces large amounts of H2. So in the moistened devices H2 in the proportion of the total volume of hydrocarbons is higher.,有时局部放电和绝缘受潮同时存在，并且特征气体基本相同，所以单靠油中气体分析难以区分，必要时根据外部检查和其它试验结果（如局部放电测试结果和油中微量水分分析）加以综合判断。,Sometimes partial discharge and humidified insulation exist at the same time. The characteristics of gas are basically the same. Therefore it is hardly to distinguished only through gas in oil . The external inspection and other test results (such as partial discharge test results and minim moisture in oil analysis) can be used to judge integrated if necessary .,6.1.2 油中溶解气体的在线监测 6.1.2 On-line monitoring of dissolved gases in oil,变压器油中溶解气体在线检测根据不同的原则可以分为不同的种类。以检测对象分类可归结为以下几类： Dissolved gases in transformer oil can be divided into different categories by different principles. It can be summed up as followed based on detect objects :,测量可燃性气体含量（TCG），包括H2、CO和各类气体烃类含量的总和 measure combustible gas content (TCG), including H2, CO and the sum of hydrocarbon content of gases 测量单种气体浓度 measure single gas concentration 测量多种气体组分的浓度 measure various gases concentration,油中溶解气体在线检测装置主要由脱气、混合气体分离及气体检测三大部分组成。 On-line detect devices of dissolved gas in oil are mainly compose of degassing part, mixed gas separation part and gas detection part.,1.脱气 Degassing,脱气法主要有油中吹气法、抽真空取气法、分离膜渗透法，表6-1给出了简单的优缺点比较结果。其中平板分离膜、毛细管柱、血液透析装置、中空纤维装置都属于高分子分离膜的应用，其它都属于抽真空脱气法。,Degassing mainly contains oil inflatable, vacuum gas sampling method, membrane permeability. Table 6-1 gives a simple comparison between the advantages and disadvantages of the results. The flat membrane, capillary column, hemodialysis device, hollow fiber devices are all the applications of polymer membrane .The others are all vacuum degassing.,表61 油气分离方法比较 Table 6-1 Comparison of oil and gas separation method,目前典型的吹气方法有三种：载气洗脱法、空气循环法和比色池法，其基本原理是采用吹气方式将溶解于油中的气体替换出来，使油面上某种气体的浓度与油中气体的浓度逐渐达到平衡。,There are three typical ways of blowing : containing gas cleared, the air circulation method and color pool method. The basic principle is to use blowing ways to replace the gas dissolved in the oil which makes concentration of gas in oil surface. The concentration of oil in the gas gradually balanced.,波纹管法是利用小型电机带动波纹管反复压缩，多次抽真空，将油中溶解气体抽出来，废油仍回到变压器中。 Bellows method means using small motor driven bellows repeated compression, repeatedly vacuum . It will take out the dissolved gas in oil. The waste oil will still come back to the transformer. 真空泵脱气法是利用常规色谱分析中的抽真空脱气原理，用真空泵抽空气来抽取油中溶解气体，废油仍回到变压器油箱。 Vacuum degassing method is using vacuum degassing principle of conventional chromatography analysis, using the vacuum pump to take out dissolved gas in oil, the waste oil will still come back to the transformer tank.,抽真空法主要包括波纹管法和真空泵脱气法。 Vacuum method includes bellows method and vacuum degassing method.,分离膜渗透法是结构简单、成本低、操作方便，因此得到了广泛应用，目前采用的透气膜主要有聚四氟乙烯、聚酰亚胺、聚丙烯、聚六氟乙烯、聚四氟乙烯混合膜、中空纤维膜以及无机膜如钯银合金金属膜等，其中高分子透气膜应用更为广泛，例如日本三菱株式会社利用聚四氟亚乙基全氟烷基乙烯基醚（PFA）膜从油中有效脱出CH4、C2H6、C2H4、C2H2、H2和CO六种气体。 Separation membrane osmosis method is a simple str