三元催化器，是安裝在汽車排氣系統(tǒng)中重要的機(jī)外凈化裝置，它可將汽車尾氣排出的CO一氧化碳、HC碳?xì)浠衔锖蚇Ox氮氧化物等有害氣體通過(guò)氧化和還原作用轉(zhuǎn)變?yōu)闊o(wú)害的二氧化碳、水和氮?dú)?。由于這種催化器可同時(shí)將廢氣中的三種主要有害物質(zhì)轉(zhuǎn)化為無(wú)害物質(zhì)，故稱三元。下面濟(jì)南沃爾沃汽車維修哪家好人員來(lái)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(guò)高

1. The temperature is too high

常溫下三元催化轉(zhuǎn)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(zhuǎn)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(zhuǎn)化器工作時(shí)會(huì)產(chǎn)生大量的自量越高，氧化的溫度也愈高，當(dāng)溫度超過(guò)850—1000℃時(shí)，其內(nèi)涂層的催化劑很可能會(huì)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(diǎn)火時(shí)間過(guò)遲或點(diǎn)火次序錯(cuò)亂、斷火等，這都會(huì)使未燃燒的混合氣進(jìn)入催化反應(yīng)器，造成排氣溫度過(guò)高，影響催化轉(zhuǎn)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(duì)硫、鉛、磷、鋅等元素非常敏感，硫和鉛來(lái)自于汽油，磷和鋅來(lái)自于潤(rùn)滑油，這四種物質(zhì)及它們?cè)诎l(fā)動(dòng)機(jī)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(wú)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(dāng)汽車長(zhǎng)期工作于低溫狀態(tài)時(shí)，三元催化器無(wú)法啟動(dòng)，發(fā)動(dòng)機(jī)排出的炭煙會(huì)附著在催化劑的表面，造成無(wú)法與CO和HC接觸，長(zhǎng)期下來(lái)，便使載體的孔隙堵塞，影響其轉(zhuǎn)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(zhuǎn)化器對(duì)污染物的轉(zhuǎn)化能力有一定的限度，因此必須通過(guò)機(jī)內(nèi)凈化技術(shù)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(guò)大，比如混合氣偏濃等，就會(huì)影響催化器的催化轉(zhuǎn)化能力，降低其轉(zhuǎn)化效率。此外，由于廢氣中有大量的HC和CO進(jìn)入催化反應(yīng)器后，會(huì)在其中產(chǎn)生過(guò)度的氧化反應(yīng)，氧化反應(yīng)產(chǎn)生大量熱量將使催化反應(yīng)器溫度過(guò)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(dòng)機(jī)不匹配

5. Mismatch with engine

即使是同樣的發(fā)動(dòng)機(jī)，同樣的三元催化轉(zhuǎn)化器，車型不同，發(fā)動(dòng)機(jī)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(huì)影響三元催化轉(zhuǎn)化器的催化轉(zhuǎn)化效果。因此，不同的車輛，應(yīng)使用不同的三元催化轉(zhuǎn)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(dá)到佳，必然在發(fā)動(dòng)機(jī)排氣管中安裝氧傳感器并實(shí)現(xiàn)閉環(huán)控制，其工作原理是氧傳感器將測(cè)得廢氣中氧的濃度，轉(zhuǎn)換成電信號(hào)后發(fā)送給ECU，使發(fā)動(dòng)機(jī)的空燃比控制在一個(gè)狹小的、接近理想的區(qū)域內(nèi)，若空燃比大時(shí)，雖然CO和HC的轉(zhuǎn)化率略有提高，但NOx的轉(zhuǎn)化率急劇下降為20%，因此必須保證佳的空燃比，實(shí)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(guān)鍵是要保證氧傳感器工作正常。如果燃油中含鉛、硅就會(huì)造成氧傳感器中毒。此外使用不當(dāng)，還會(huì)造成氧傳感器積碳、陶瓷碎裂、加熱器電阻絲燒斷、內(nèi)部線路斷脫等故障。氧傳感器的失效會(huì)導(dǎo)致空燃比失準(zhǔn)，排氣狀況惡化，催化轉(zhuǎn)化器效率降低，長(zhǎng)時(shí)間會(huì)使催化轉(zhuǎn)化器的使用壽命降低。更多相關(guān)事項(xiàng)就來(lái)我們網(wǎng)站http://nikond90.cn進(jìn)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://nikond90.cn Get to know!