Exhaust gas post-processing device, exhaust gas temperature control system before scr and control method thereof

Abstract

The invention relates to an exhaust gas post-processing device, an exhaust gas temperature control system before SCR and a control method thereof. The exhaust temperature control system before the SCR includes a urea storage device, a urea pump, a urea supply control valve, a urea injector, an exhaust temperature sensor and a controller, and also includes a cooling channel for connecting the DPF and the SCR and allowing the exhaust gas to pass through; among them, The urea injector communicates with the cooling channel, and the urea pump is respectively connected with the urea storage device and the urea injector and is connected with the controller. The urea storage device includes non-thermal regeneration urea for storing the urea solution used in non-DPF thermal regeneration The storage chamber and the urea storage chamber for thermal regeneration used to store the urea solution used for thermal regeneration of the DPF, the urea storage chamber for thermal regeneration is used to store a lower concentration of urea solution than the urea solution used for non-DPF thermal regeneration concentration. The above-mentioned technical solution solves the technical problem that the exhaust gas temperature control system before the SCR is complicated and expensive in the prior art.

Description

technical field [0001] The invention relates to the technical field of exhaust gas post-treatment of internal combustion engines, in particular to an exhaust gas post-processing device, an exhaust gas temperature control system before SCR and a control method thereof. Background technique [0002] There are two types of purification of diesel engine exhaust: organic internal purification and exhaust post-treatment. The after-treatment devices of diesel engines include DOC (oxidation catalytic converter), DPF (particulate filter), SCR (selective catalytic reduction technology), etc., which in turn In series in the exhaust system of the diesel engine. Among them, DPF is used to reduce engine particulate (PM) emissions. After the DPF has been used for a period of time, the particles adhere to the surface of the DPF, which affects the exhaust flow, increases fuel consumption, and deteriorates the economy of the diesel engine. At this time, it is necessary to remove the PM accum...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a kind of exhaust gas temperature control system before SCR, to solve the technical problem that the exhaust gas temperature control system before SCR in the prior art is more complicated, the cost is higher; The purpose of the present invention is also to provide an exhaust gas Post-processing device to solve the technical problems of complex structure and high cost of exhaust gas post-processing device in the prior art; the purpose of the present invention is to provide a control method that can effectively control the exhaust temperature before SCR

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