Device and method for controlling inlet temperature of three-way catalytic converter according to OBD monitoring efficiency

Abstract

The invention discloses a device and method for controlling the inlet temperature of a three-way catalytic converter according to OBD monitoring efficiency. The device comprises an exhaust pipe, a three-way catalytic converter, an electric heating device and an engine electronic control system, wherein the exhaust pipe comprises an engine exhaust gas inlet end; the inlet end of the three-way catalytic converter is connected with the engine exhaust gas inlet end; the electric heating device is arranged at the outer part of the exhaust pipe, distributed close to the inlet end of the three-way catalytic converter and used for heating exhaust gas before the inlet end of the three-way catalytic converter; and the engine electronic control system comprises an electronic control unit, an OBD system, an exhaust temperature sensor, a concentration sensor and a control relay, wherein the electronic control unit is separately electrically connected with the exhaust temperature sensor, the controlrelay and front and rear oxygen sensors, and the electronic control unit can control the working state of the electric heating device by controlling the connection and disconnection of the control relay. According to the device, the inlet temperature of the three-way catalytic converter can be raised in the cold starting and machine heating process of the engine, and the converting efficiency ofthe three-way catalytic converter is increased.

Description

technical field [0001] The invention relates to the technical field of engine aftertreatment, in particular to a device and method for controlling the inlet temperature of a three-way catalytic converter according to OBD monitoring efficiency. Background technique [0002] In order to meet the requirements of the new emission regulations, the natural gas engine adopts the combustion technology route of equivalent + EGR (exhaust gas recirculation) + TWC (three-way catalytic converter). Since the three-way catalytic converter requires a certain temperature for ignition, during cold start and warm-up process, due to the low temperature at the inlet of the three-way catalytic converter, the conversion efficiency of the three-way catalytic converter is low, and with the passage of time, the three-way After the catalytic converter deteriorates, the required light-off temperature increases, and the conversion efficiency of the catalytic converter decreases. In order to meet the re...

AI Technical Summary

Problems solved by technology

Since the three-way catalytic converter requires a certain temperature for ignition, during cold start and warm-up process, due to the low temperature at the inlet of the three-way catalytic converter, the conversion efficiency of the three-way catalytic converter is low, and with the passage of time, the three-way After the catalytic converter deteriorates, the required light-off temperature increases, and the conversion efficiency of the catalytic converter decreases

In order to meet the requirements of emission and endurance mileage, in view of the above two problems, the existing natural gas engine solves the problem of low conversion efficiency of the three-way catalytic converter in the process of cold start and heat engine by increasing the content of precious metals. The manufacturing cost is increased, and the pipeline in front of the three-way catalytic converter is too long, which greatly restricts the arrangement of the three-way catalytic converter on the whole vehicle

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