Exhaust gas after-treatment box for heat preservation by using the treated exhaust gas

Abstract

An exhaust gas aftertreatment box includes: a box body (1); an oxidation catalyst (2), a reducing agent mixer (3) and a selective catalytic reduction device (4, 5 ) that are sequentially passed through by the exhaust gas. (1) carrying and the main body is located in the inner space of the box body (1), the outlet ports (42, 52) of the selective catalytic reduction device (4, 5) are communicated with the inner space of the box body (1); the reducing agent an injector (9), which is arranged to inject reducing agent into the reducing agent mixer (3); and an exhaust gas outlet (14), which is arranged on the tank (1) and opens into the inner space of the tank (1) , so that the treated tail gas discharged from the selective catalytic reduction device (4, 5) flows through the inner space of the box body (1), and then is discharged out of the tail gas post-treatment box through the tail gas outlet (14).

Description

technical field [0001] The present application relates to an integrated exhaust gas after-treatment box for treating exhaust gas emitted by an engine. Background technique [0002] Engine exhaust contains harmful components. In order to reduce the emission of harmful components in exhaust gas, various after-treatment technologies have been developed. A typical integrated exhaust aftertreatment box for diesel engines suitable for installation on both sides of the vehicle chassis includes a diesel oxidation catalyst (DOC), a selective catalytic reduction (SCR) and a diesel particulate filter (DPF). ). [0003] DOC), SCR, and DPF cannot exert their full effectiveness under low temperature conditions, and may even fail to work. Therefore, it is necessary to maintain the necessary temperature in the exhaust aftertreatment tank. For this reason, according to the prior art, an insulating material is provided in the exhaust gas after-treatment box to avoid excessively low temper...

AI Technical Summary

Problems solved by technology

However, adding insulation will undoubtedly increase the overall cost of the exhaust aftertreatment box

In addition, when the engine is running at low power, the temperature of the exhaust gas is low. Even in the presence of insulation materials, it is sometimes difficult to maintain the temperature required for the catalyst in the exhaust treatment element to work properly, which makes it difficult for the exhaust aftertreatment box to achieve In the best working condition, the exhaust gas treatment capacity is low, resulting in the exhaust gas not meeting high-level exhaust emission requirements, such as Euro VI standards and Real Driving Emissions (RDE) test requirements, etc.

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