CN202325770U

CN202325770U - SCR (silicon controlled rectifier) system with external mixing nozzle metering structure

Info

Publication number: CN202325770U
Application number: CN2011203708517U
Authority: CN
Inventors: 郝庆军
Original assignee: Suzhou Powergreen Emission Solution System Co Ltd
Current assignee: Suzhou Powergreen Emission Solution System Co Ltd
Priority date: 2011-10-02
Filing date: 2011-10-02
Publication date: 2012-07-11
Anticipated expiration: 2021-10-02

Abstract

The utility model discloses an SCR (silicon controlled rectifier) system with an external mixing nozzle metering structure. The SCR system comprises a urea box for storing a reducing agent, a urea pump, a metering valve, a nozzle and an air source, wherein the metering valve is communicated with the urea pump via a pipeline, the air source is communicated with the nozzle via a pipeline, the metering valve is arranged on the nozzle, and an airflow in the air source is mixed with the reducing agent ejected by the metering valve in the nozzle; and the nozzle comprises a urea tube, an air cap and an airflow gap formed between the urea tube and the air cap. The SCR system disclosed by the utility model is high in integration level, and is convenient to control; and the external mixing nozzle structure is simple, and is good in atomizing and mixing effects.

Description

SCR system with external mix nozzle measurement structure

Technical field

The utility model relates to a kind of exhaust gas from diesel vehicle post-processing purifying system, relates in particular to a kind of SCR system with external mix nozzle measurement structure.

Background technique

Existing known; Nitrogen oxide through in SCR technology (SCR) the minimizing internal-combustion engine especially diesel engine vent gas is a kind of general technology path; Be about to reducing agent (aqueous solution of urea) through atomizing quantitative injection intake and exhaust pipeline; And through the SCR catalyzer the main harmful gas NOx in the waste gas is changed into the nitrogen G&W and discharge, reach the purpose of tail gas clean-up.

In the existing technology, aqueous solution of urea metered injection device is divided into has two kinds in gas and no gas, has the gas jet system mainly to rely on pump that reducing agent is pumped into the metering valve inlet; In mixing chamber, high velocity air carries out the reducing agent that ejects primary atomization and is blown into the nozzle place through the accurate metered injection of metering valve, carries out atomized spray in the nozzle ejection process once more in gas exhaust piping; This system is through the secondary injection atomizing; Atomizing effect is good, but this structure is complicated, the pressure control in the pipeline is required high; Power consumption is big, and control is complicated; Another kind is an airless injection system; The most typical with the DENOXTRONIC2.2 system of BOSCH company in industry, promptly metering valve is set directly on the outlet pipe, through direct metered injection of metering valve and atomizing; Though this system is simple in structure; But metering valve is burnt out erosion easily near outlet pipe, owing to can only lean on the liquid discharging pressure atomization, atomizing effect is poor simultaneously.

In order to address the above problem; The applicant discloses a kind of Chinese patent (patent No. is 201020276173.3) of direct spray type metered injection device; Should outer mixed construction use in gas control system system is arranged, can reduce back pressure, can solve the atomizing problem simultaneously, but structure be also complicated.

In addition, SCR system architecture simplification problem is the main body of present metering injection system, and how simplifying the SCR system, to reach rational control mode be the domestic and international subject matter that faces of each producer.

The model utility content

The purpose of the utility model is to overcome the defective of existing technology, proposes that a kind of to have an atomizing effect good, and level of integration is high, and the SCR system with external mix nozzle measurement structure simple in structure, improves tail gas clean-up efficient.

For realizing above-mentioned purpose; The utility model proposes following technological scheme: the SCR system with external mix nozzle measurement structure; The urea box, urea pump, metering valve, nozzle and the source of the gas that comprise the storage and reduction agent, said metering valve and said urea pump be pipeline connection mutually; Said source of the gas and nozzle be pipeline connection also, and said metering valve is arranged on the nozzle, and the air-flow in the said source of the gas mixes in nozzle with the reducing agent that metering valve ejects mutually; Said nozzle comprises urea pipe, air cap and is formed at the airflow clearance between urea pipe and air cap.Said metering valve is arranged on the nozzle.

Said urea pump is arranged in the urea box.

Also be provided with pressure regulator valve in the said urea box, said pressure regulator valve is connected on the downstream of said urea pump.

Said metering valve provided upstream is equipped with sensor.

Said nozzle also comprises flanged plate and distribution cover, and said distribution is set between said air cap and the said flanged plate, forms air-flow path between said flanged plate, distribution cover and the air cap.

The SCR system that the utlity model has external mix nozzle measurement structure also comprises heating unit, and said heating unit is arranged in the said urea box.

Compared with prior art, the utlity model has the SCR system of external mix nozzle measurement structure, level of integration is high, and outer hybrid nozzle arrangements is simple, and the atomizing good mixing effect also be difficult for being burnt out, and whole system control is convenient, has reduced component.

Description of drawings

Fig. 1 is the SCR systematic schematic diagram that the utlity model has external mix nozzle measurement structure;

Fig. 2 is the stereogram of the utility model nozzle arrangements;

Fig. 3 is the sectional view of the utility model nozzle arrangements.

Embodiment

To combine the accompanying drawing of the utility model below, the technological scheme in the utility model preferred embodiment will be carried out clear, complete description.

As shown in Figure 1; The utlity model has the SCR system of external mix nozzle measurement structure; Comprise urea box 1, urea pump 2, pressure regulator valve 5, sensor 14, metering valve 3 and nozzle 6, the pipeline series connection successively of said urea pump 2, pressure regulator valve 5, filter 12, sensor 14, metering valve 3 and nozzle 6, said urea pump 2 is pumped into metering valve 3 inlets with the reducing agent that stores in the urea box 1; 3 pairs of accurate metered injections of reducing agent of metering valve; Be ejected in the outlet pipe 15 through the nozzle 6 that is directly installed on the outlet pipe 15, said pressure regulator valve 5 can play the effect of the pressure at the stabilimeter metered valve upper reaches again, prevents that reducing agent from producing pressure surge in course of conveying.

In the utility model; Said metering valve 3 is arranged on the said nozzle 6, goes back pipeline on the nozzle 6 and is connected with outside air source of the gas 7, and the air stream that produces in the air source of the gas 7 like this can provide for the injection of reducing agent and blow pressure; And since pressure regulator valve 5 can stabilimeter metered valve 3 upper reaches force value; Therefore the back pressure of outlet pipe 15 can be offset by the vacuum that outer mixed gas produces, so the pressure differential deltap P of metering valve upstream and downstream is the force value at the metering valve upper reaches, is may command pressure reduction through the pressure on the side quantity sensor 14; Outer mixed construction also can be for nozzle 6 provides cooling effect simultaneously, and it is ablated to prevent that metering valve 3 is directly installed on the outlet pipe 15.

Like Fig. 2, shown in Figure 3, the outer hybrid nozzle 6 of the utility model comprises urea pipe 61, flanged plate 62, distribution cover 63 and air cap 65, and said distribution cover 63 is arranged between said air cap 65 and the said flanged plate 62; Said urea pipe 61 passes said flanged plate 62 and distribution cover 63 from top to bottom successively, and extends to the bottom of said

air cap

65, and 65 of said urea pipe 61 and air caps form airflow clearance 66; Form spout 64 between the outlet of said urea pipe 61 and the airflow clearance 66; Form air-flow path between said flanged plate 62, distribution cover 63, airflow clearance 66 and the spout 64, when urea pipe 61 and spout 64 were spurted into outlet pipe 15 in, the air-flow while blowed through the said flow passage at reducing agent; Fully mix at spout 64 place's reducing agents and air; And fully atomizing under compressed-air actuated blowing, in this structure, all air pipe lines and mixed pipe line all are arranged on the inside of said nozzle 6; Basically do not receive outside Effect of Hyperthermic Environment; Other pipeline that reducing agent is carried does not have harsh pressure requirement yet, and is simple in structure, and control is convenient.

The SCR system that the utlity model has external mix nozzle measurement structure also comprises measurement control unit (DCU) 8; Said measurement control unit 8 signals connect said urea pump 2, metering valve 3 and sensor 14, and the action of control urea pump 2 and the metered injection of metering valve.

Said SCR system with external mix nozzle measurement structure also comprises filter 12; The upper reaches that said filter 12 is arranged on said metering valve (both can be arranged on outside the urea box; Also can be arranged in the urea box); Said filter carries out filter cleaning to the reducing agent in the pipeline, prevents that dust impurity from getting in the delivery line.

As shown in Figure 1, the SCR system that the utlity model has external mix nozzle measurement structure also comprises heating unit 4, and said heating unit 4 is arranged in the said urea box 1; Said urea pump 2 also is arranged in the said urea box 1; Said filter 12, sensor 14 etc. are integrated on the urea box 1, and integrated design can avoid each unit to heat respectively, and heating unit 4 can heat the pipeline between these parts when reducing agent heats in to urea box; Avoiding separately, heating increases cost; The urea pump embedding structure also can be avoided the pumping pipeline is heated separately, in the reducing agent in the heating urea case reducing agent in the pumping pipeline is heated, in addition; The urea pump embedding structure can reduce back pressure, and it is stable to keep discharge pressure.

In the utility model, the air-flow that air source of the gas 7 provides can fully mix and atomize in nozzle 6 with the reducing agent that metering valve 3 ejects, and improves jet pressure, and reducing agent is spurted in the outlet pipe 15 through nozzle 6.

Preferably, said urea pump 2 is arranged near the heat exchanger of bottom in the said heating unit 4, is convenient to reducing agent in the back suction of thawing.

The SCR level of integrated system that the utlity model has external mix nozzle measurement structure is high, and heats is good, the highly integrated arrangement space of having saved; Outer hybrid nozzle reduces or offsets back pressure in the pipeline, and mixed aerosol is effective, is arranged on also to be difficult in the outlet pipe being burnt; The pressure regulator valve control accuracy is high, and simultaneously, the urea pump embedding structure can reduce back pressure; The whole system pressure stability, the working life of improving urea pump.

Claims

1. SCR system with external mix nozzle measurement structure; The urea box, urea pump, metering valve, nozzle and the source of the gas that comprise the storage and reduction agent; Said metering valve and said urea pump pipeline connection; It is characterized in that: said source of the gas and nozzle be pipeline connection also, and said metering valve is arranged on the nozzle, and the air-flow in the said source of the gas mixes in nozzle with the reducing agent that metering valve ejects mutually; Said nozzle comprises urea pipe, air cap and is formed at the airflow clearance between urea pipe and air cap.

2. the SCR system with external mix nozzle measurement structure according to claim 1, it is characterized in that: said urea pump is arranged in the urea box.

3. the SCR system with external mix nozzle measurement structure according to claim 2 is characterized in that: also be provided with pressure regulator valve in the said urea box, said pressure regulator valve is installed in the downstream of said urea pump.

4. the SCR system with external mix nozzle measurement structure according to claim 3 is characterized in that: said metering valve provided upstream is equipped with sensor.

5. according to any described SCR system with external mix nozzle measurement structure of claim 1 to 4, it is characterized in that: the SCR system with external mix nozzle measurement structure also comprises heating unit, and said heating unit is arranged in the said urea box.

6. the SCR system with external mix nozzle measurement structure according to claim 1; It is characterized in that: said nozzle also comprises flanged plate and distribution cover; Said distribution is set between said air cap and the said flanged plate, forms air-flow path between said flanged plate, distribution cover and the air cap.