A gas-liquid hybrid engine exhaust post-treatment injection device

Abstract

A gas-liquid mixing type engine exhaust after-treatment jet apparatus comprises a pulse pump, a mixing jet unit, a nozzle, an ejector, a controller and an air source. The mixing jet unit comprises an ejecting cavity, a gas cavity, a nozzle positioning hole communicated with the gas cavity, an air inlet channel, and a limiting hole. The pulse pump comprises a lead for receiving signals and a lead interface, a control signal sent from the controller is transmitted to the pulse pump via the lead to drive the pulse pump to work, and the pulse pump provides the nozzle with a jet flow source. The nozzle sprays liquid to the ejecting cavity, space of the ejecting cavity is arranged in the spraying direction of the liquid, the gas cavity is positioned near a vent of the nozzle, and pressure in the gas cavity is reduced due to the fact that the liquid is sprayed. The purpose of the present invention aims at providing an exhaust after-treatment system that is high in reliability, simple in structure, convenient in installation, replacement and maintenance, and low in cost.

Description

Technical field [0001] The invention belongs to the technical field of engine exhaust aftertreatment, and specifically relates to a NOx selective catalytic reduction (SCR) system for engine exhaust aftertreatment, a diesel particulate matter capture filtration (DPF) regenerative injection system, and their control technology. Background technique [0002] Nowadays, vehicles powered by internal combustion engines need to install emission aftertreatment systems to meet increasingly stringent emission requirements. For example, SCR (Selective Catalytic Reduction) technology, which is currently mainly used for catalytic treatment of pollutants such as NOx in diesel engine exhaust, and diesel particulate matter (DPF) regeneration technology, are mainly used. [0003] SCR technology requires, for example, a 32.5% by weight aqueous solution of urea (also called diesel exhaust treatment fluid DEF = Diesel Exhaust Fluid, or AdBlue) quantitatively injected into the diesel engine exhaust, and...

AI Technical Summary

Problems solved by technology

Due to the high surface tension of the DEF working fluid, when filling the DEF working fluid, the liquid often cannot pass through the filter smoothly into the SCR metering pump, resulting in the difficulty of initial liquid intake

In addition, the SCR metering pump will generate a large amount of steam when it is working. If it cannot be removed in time, it will affect its normal work and cooling.

[0008] In addition, existing technology is difficult to work in any climate without auxiliary heating at all

Since the existing device for providing the jet power source is too large or cannot be implanted into the DEF liquid storage tank due to other reasons, an auxiliary ice-melting device is required, which makes the system more complex and bulky, and the cost remains high

Therefore, solving the problem of complex system structure is a realistic and urgent problem.

For solving the above problems, there are many factors such as high cost and inconvenient installation in the prior art, which need to be further improved.

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