汽车发动机三元催化转化器的过热保护

Overheat Protect of Three-Way Catalyst Converter of Gasoline Engines

随着三元催化转化器的广泛应用,由于烧蚀和活性降低而损坏的催化器不断增多。究其原因大多是排气温度过高所致。考虑到目前还没用采用排气温度传感器,本文采用一种排气温度预测方法来保护催化器:从发动机运行工况中预测排气温度,当超过保护限值时,调整空燃比来降低排气温度。试验证明有一定效果。

The number of destroyed and invalid TWC increases because of overheated exhaust temperature. Thanks to no using exhaust temperature sensor to measure the temperature,the article presents a method of predicting the temperature of TWC to protect it. The exhaust temperature is predicted according to the conditions of engine operating,and as the temperature is over the protecting limit,the exhaust temperature will be decreased by adjusted air-fuel ratio. The test proves that this method has a certain effect.