Calculation method and fault diagnosis method of tail gas treatment system and its hydrocarbon conversion efficiency

Abstract

The invention discloses a tail gas treatment system and its DPF temperature control system and control method, including a catalyst conversion device, the catalyst conversion device includes a tail gas channel, a conical constriction, a DOC and a DPF, and an external hydrocarbon is connected to the tail gas channel For the injection device, a first temperature sensor is installed upstream of the DOC, a first differential pressure sensor is installed upstream of the DOC, a second temperature sensor and a third temperature sensor are respectively installed upstream and downstream of the DPF, and a sensor for measuring the outlet of the DPF is installed on the DPF. The second differential pressure sensor for the pressure and the differential pressure passing through the DPF; the controller is electrically connected to the internal combustion engine, the first temperature sensor, the second temperature sensor, the third temperature sensor, the first differential pressure sensor and the second differential pressure sensor. According to the hydrocarbon conversion efficiency of DOC and DPF, the present invention can accurately judge whether there is a fault in the tail gas treatment system, and prepares to determine the type of the fault for maintenance, thereby shortening the time for judgment of the fault.

Description

technical field [0001] The invention relates to a tail gas treatment system, in particular to a tail gas treatment system and a method for calculating the conversion efficiency of hydrocarbons and a fault diagnosis method thereof. Background technique [0002] Exhaust gas discharged from the engine has been identified as the main cause of air pollution, and an exhaust gas treatment system can be used to remove air pollutants in the exhaust gas in the prior art. In exhaust treatment systems, diesel particulate filters (DPF) are commonly used to capture particulate matter (PM), which may include unburned hydrocarbon particles (soot) and small amounts of other particles such as metal oxide particles (ash) . Particulate matter accumulates in the DPF and requires a regeneration process to remove accumulated soot before the accumulation causes excessive back pressure in the engine. [0003] Usually during regeneration, a heat generating device is used to raise the temperature of...

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Problems solved by technology

[0007] Low hydrocarbon conversion efficiencies can be caused by "real" inefficiencies caused by problems in the heat generating unit and DPF (e.g. plugged DOC, sulfur poisoning, catalyst particle buildup in the DOC or DPF, etc.), or by problems with hydrocarbon metering injection "Show" inefficiencies (e.g. inaccurate hydrocarbon metering injection)

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