三元催化器，是安裝在汽車排氣系統(tǒng)中重要的機外凈化裝置，它可將汽車尾氣排出的CO一氧化碳、HC碳氫化合物和NOx氮氧化物等有害氣體通過氧化和還原作用轉變?yōu)闊o害的二氧化碳、水和氮氣。由于這種催化器可同時將廢氣中的三種主要有害物質轉化為無害物質，故稱三元。下面濟南沃爾沃汽車維修哪家好人員來講講汽車三元催化器失效的原因。

A three-way catalytic converter is an important external purification device installed in the automotive exhaust system. It can convert harmful gases such as CO, HC hydrocarbons, and NOx nitrogen oxides emitted from automotive exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction. Due to the fact that this catalytic converter can simultaneously convert the three main harmful substances in the exhaust gas into harmless substances, it is called ternary. Which good maintenance personnel from Jinan Volvo Cars will explain the reasons for the failure of the three-way catalytic converter in cars.

1.溫度過高

1. The temperature is too high

常溫下三元催化轉化器不具備催化能力，其催化劑必須加熱到一定溫度才具有氧化或還原的能力，通常催化轉化器的起燃溫度在250—350℃，正常工作溫度一般在350—700℃。

At room temperature, a three-way catalytic converter does not have catalytic ability, and its catalyst must be heated to a certain temperature to have the ability to oxidize or reduce. Usually, the ignition temperature of the catalytic converter is between 250-350 ℃, and the normal operating temperature is generally between 350-700 ℃.

催化轉化器工作時會產生大量的自量越高，氧化的溫度也愈高，當溫度超過850—1000℃時，其內涂層的催化劑很可能會脫落，載體碎裂。所以必須注意控制造成排氣溫度升高的各種因素，如點火時間過遲或點火次序錯亂、斷火等，這都會使未燃燒的混合氣進入催化反應器，造成排氣溫度過高，影響催化轉化器的效能。

During the operation of catalytic converters, a large amount of self weight will be generated, and the oxidation temperature will also be higher. When the temperature exceeds 850-1000 ℃, the catalyst on its inner coating is likely to fall off and the carrier will shatter. Therefore, it is necessary to pay attention to controlling various factors that cause an increase in exhaust temperature, such as delayed ignition, disordered ignition sequence, and misfire. This can cause unburned mixture to enter the catalytic reactor, resulting in high exhaust temperature and affecting the efficiency of the catalytic converter.

2.慢性中毒

2. Chronic poisoning

催化劑對硫、鉛、磷、鋅等元素非常敏感，硫和鉛來自于汽油，磷和鋅來自于潤滑油，這四種物質及它們在發(fā)動機中燃燒后形成氧化物顆粒易被吸附在催化劑的表面，使催化劑無法與廢氣接觸，從而失去了催化作用，即所謂的“中毒”現(xiàn)象。

Catalysts are very sensitive to elements such as sulfur, lead, phosphorus, and zinc. Sulfur and lead come from gasoline, while phosphorus and zinc come from lubricating oil. These four substances and their oxide particles formed after combustion in the engine are easily adsorbed on the surface of the catalyst, preventing it from coming into contact with exhaust gas and thus losing its catalytic effect, known as the "poisoning" phenomenon.

3.表面積碳

3. Surface area carbon

當汽車長期工作于低溫狀態(tài)時，三元催化器無法啟動，發(fā)動機排出的炭煙會附著在催化劑的表面，造成無法與CO和HC接觸，長期下來，便使載體的孔隙堵塞，影響其轉化效能。

When the car is operated at low temperatures for a long time, the three-way catalytic converter cannot start, and the carbon smoke emitted by the engine will adhere to the surface of the catalyst, causing it to be unable to contact CO and HC. Over time, it will block the pores of the carrier and affect its conversion efficiency.

4.排氣惡化

4. Exhaust deterioration

催化轉化器對污染物的轉化能力有一定的限度，因此必須通過機內凈化技術將原始排氣降到低。如果排放的廢氣污染物各成分的濃度、總量過大，比如混合氣偏濃等，就會影響催化器的催化轉化能力，降低其轉化效率。此外，由于廢氣中有大量的HC和CO進入催化反應器后，會在其中產生過度的氧化反應，氧化反應產生大量熱量將使催化反應器溫度過高而損壞。

The catalytic converter has a certain limit on its ability to convert pollutants, so it is necessary to reduce the original exhaust through internal purification technology. If the concentration and total amount of various components of exhaust pollutants emitted are too high, such as a concentrated mixture, it will affect the catalytic conversion ability of the catalytic converter and reduce its conversion efficiency. In addition, due to the large amount of HC and CO in the exhaust gas entering the catalytic reactor, excessive oxidation reactions will occur, and the large amount of heat generated by the oxidation reaction will cause damage to the catalytic reactor due to excessive temperature.

5.與發(fā)動機不匹配

5. Mismatch with engine

即使是同樣的發(fā)動機，同樣的三元催化轉化器，車型不同，發(fā)動機常用的工作區(qū)間就不同，排氣狀況就發(fā)生變化，安裝三元催化器的位置就不同，這都會影響三元催化轉化器的催化轉化效果。因此，不同的車輛，應使用不同的三元催化轉化器。

Even with the same engine, the same three-way catalytic converter, and different vehicle models, the commonly used operating range of the engine varies, resulting in changes in exhaust conditions and different installation positions of the three-way catalytic converter. This will affect the catalytic conversion effect of the three-way catalytic converter. Therefore, different vehicles should use different three-way catalytic converters.

6.氧傳感路失效

6. Failure of oxygen sensing circuit

為使廢氣催化率達到佳，必然在發(fā)動機排氣管中安裝氧傳感器并實現(xiàn)閉環(huán)控制，其工作原理是氧傳感器將測得廢氣中氧的濃度，轉換成電信號后發(fā)送給ECU，使發(fā)動機的空燃比控制在一個狹小的、接近理想的區(qū)域內，若空燃比大時，雖然CO和HC的轉化率略有提高，但NOx的轉化率急劇下降為20%，因此必須保證佳的空燃比，實現(xiàn)佳的空燃比。

In order to achieve optimal exhaust gas catalytic efficiency, an oxygen sensor must be installed in the engine exhaust pipe and closed-loop control must be achieved. Its working principle is that the oxygen sensor will measure the concentration of oxygen in the exhaust gas, convert it into an electrical signal, and send it to the ECU, so that the air fuel ratio of the engine is controlled in a narrow and nearly ideal area. If the air fuel ratio is large, although the conversion rates of CO and HC slightly increase, the conversion rate of NOx sharply decreases to 20%, Therefore, it is necessary to ensure a good air fuel ratio and achieve a good air fuel ratio.

關鍵是要保證氧傳感器工作正常。如果燃油中含鉛、硅就會造成氧傳感器中毒。此外使用不當，還會造成氧傳感器積碳、陶瓷碎裂、加熱器電阻絲燒斷、內部線路斷脫等故障。氧傳感器的失效會導致空燃比失準，排氣狀況惡化，催化轉化器效率降低，長時間會使催化轉化器的使用壽命降低。更多相關事項就來我們網站http://www.junwumy.com進行了解！

The key is to ensure that the oxygen sensor operates normally. If the fuel contains lead and silicon, it can cause oxygen sensor poisoning. In addition, improper use can also cause faults such as carbon deposition, ceramic fragmentation, heater resistance wire burning, and internal circuit disconnection of the oxygen sensor. The failure of oxygen sensors can lead to inaccurate air fuel ratio, deterioration of exhaust conditions, reduced efficiency of catalytic converters, and prolonged service life of catalytic converters. For more related matters, come to our website http://www.junwumy.com Get to know!