Urea nozzle cooling protection control method and device

Abstract

The embodiment of the invention provides a urea nozzle cooling protection control method and device. The method comprises the following steps that whether a SCR system satisfies a voltage buildup condition or mote is detected; when the SCR system is detected to satisfy the voltage buildup condition, the SCR system is controlled to perform voltage buildup so as to enable a urea nozzle to enter a spraying waiting state; the non-spraying time of the urea nozzle and the temperature at a spraying hole of the urea nozzle are monitored, wherein the temperature is collected by an SCR upstream temperature sensor; when the non-spraying time exceeds a first preset time threshold and the temperature of the spraying hole of the urea nozzle exceeds a preset temperature interval, the urea nozzle is controlled to spraying urea; and when the urea continuous spraying time of the urea nozzle is detected to meet a second preset time threshold, the urea nozzle is stopped from urea spraying. According to the embodiment, the urea nozzle can be cooled in time after the urea nozzle is not operated for a long time in a high-temperature environment, the situation that the nozzle is damaged when urea solutionis not sprayed for a long time in a high-temperature environment is avoided, and the service life of the urea nozzle is prolonged.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of aftertreatment of diesel engine exhaust, and in particular to a cooling protection control method and equipment for urea nozzles. Background technique [0002] Selective Catalytic Reduction (SCR) is currently recognized as one of the most effective post-treatment technologies for reducing nitrogen oxide emissions in diesel engine exhaust. The SCR system of a diesel engine consists of a urea tank, a urea pump, a urea nozzle and connecting pipelines. The urea nozzle is a device for the SCR system to realize urea injection. Evaporation, pyrolysis and hydrolysis generate reducing agent ammonia, which selectively reduces nitrogen oxides to nitrogen under the action of a catalyst to reduce the content of nitrogen oxides in the tail gas. [0003] The urea nozzle of the SCR system of the diesel engine is located in the SCR box connected to the exhaust pipe. Due to the influence of the h...

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Problems solved by technology

[0005] The embodiment of the present invention provides a urea nozzle cooling protection control method and equipment to overcome the problem of overheating and damage to the nozzle in the prior art when the urea solution is not sprayed for a long time and cannot cool the nozzle hole.

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