Diesel engine tail gas selective catalytic reducing agent adding device and method

Abstract

The invention discloses a diesel engine tail gas selective catalytic reducing agent adding method and a diesel engine tail gas selective catalytic reducing agent adding device with a simple structure. The diesel engine tail gas selective catalytic reducing agent adding device comprises a normally closed reducing agent storage container, an atomizing device which is arranged in the storage container and an atomized gas outlet which is arranged in the top part of the storage container. A negative-pressure pipe of a diesel engine tail gas pipe is communicated with the atomized gas outlet. The diesel engine tail gas selective catalytic reducing agent adding method comprises the steps that the atomizing device atomizes reducing agent into small-size atomized liquid drops, and when the liquid drops meet the negative-pressure pipe communicated to the diesel engine tail gas pipe, the liquid drops are absorbed and reach the diesel engine tail gas to realize selective catalytic reduction of nitrogen oxides in the tail gas. The diesel engine tail gas selective catalytic reducing agent adding method and the diesel engine tail gas selective catalytic reducing agent adding device have the advantages that reducing agent pressure driving devices and atomizing nozzles such as electric pumps and compressed air sources which are normally used at present are not needed, the low-temperature freezing performance of the system is excellent because the part in contact with the reducing agent is only an ultrasonic atomizer, the structure of the entire system is simple, the quantity of work parts is smaller and the reliability and the economy of the system are improved.

Description

technical field [0001] The invention relates to a method and a device for treating engine tail gas, and further relates to a method and a device for adding a selective catalytic reducing agent to the tail gas of a diesel engine. Background technique [0002] Diesel engines have been widely used in various industries due to their high thermal efficiency and low exhaust emissions, but their high nitrogen oxide (NOx) emissions have long been a problem that plagues people. Selective catalytic reduction technology (SCR) is an effective method to control nitrogen oxide emissions from diesel engines. This technology usually uses a certain concentration of reducing agents (such as urea solution for vehicles, absolute ethanol, etc.) to be atomized in the exhaust pipe through high-pressure injection. Mixed with the nitrogen oxides emitted by the diesel engine, it enters the catalytic converter to complete the catalytic reduction reaction, and finally generates nitrogen and water. In ...

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