CN218407576U - Anti freezing type aftertreatment liquid nozzle - Google Patents

Abstract

The utility model provides an anti freezing type aftertreatment liquid nozzle, includes that a solenoid supplies liquid device, a reductant nozzle, a cooling jacket, a nozzle fixing support, the reductant nozzle includes an injection portion and a liquid chamber, the liquid chamber is an elasticity space, aims at providing a simple structure, environmental suitability is good, simple to operate's anti freezing type aftertreatment liquid nozzle.

Description

Anti freezing type aftertreatment liquid nozzle

Technical Field

The invention belongs to the field of engine emission control, and particularly relates to a urea liquid supply metering system of an engine exhaust selective reduction (SCR) technology.

Background

Selective Catalytic Reduction (SCR) technology is one of the most effective aftertreatment technologies currently known to reduce the emission of nitrogen oxides in diesel engine exhaust. The SCR technology is to inject a urea aqueous solution of 32.5% by weight concentration quantitatively into the exhaust gas of a diesel engine, decompose the exhaust gas into ammonia gas at high temperature, mix the ammonia gas with the exhaust gas, and then enter an SCR catalytic converter, where the ammonia gas and NOx in the engine exhaust gas undergo catalytic reduction reaction under the action of a catalyst, so that the NOx is decomposed into harmless N2 and H2O.

On one hand, the liquid reducing agent nozzle of the SCR system realizes the delivery of the metered liquid through a pipeline and a high-pressure liquid injection runner, the injection end is difficult to avoid the residual working liquid due to the complex pipeline or the abnormal power failure of the system and other reasons, the freezing of the working liquid can cause the volume increase in the low-temperature environment, if no special countermeasure is provided, the pressure resistance requirement on each part of the nozzle is very high, and the fault that the nozzle is damaged due to freezing can often occur.

On the other hand, a liquid reducing agent nozzle of the SCR system is directly arranged on the exhaust pipe, particularly an electromagnetic drive type nozzle has higher requirements on the temperature resistance of the nozzle, and the existing reducing agent nozzle adopts a water cooling structure. Because the nozzle is designed around the spray end of the nozzle due to the structure and space of the nozzle, in a low-temperature environment, because the temperature of the part of the cooling water cavity is slowly reduced, residual liquid in the nozzle is finally frozen, the probability that the weak part in the nozzle fails due to volume expansion caused by freezing is higher, working liquid leaks, and the like, so that the normal work of a vehicle power system and a tail gas aftertreatment system is influenced.

In summary, due to the structural characteristics of the nozzle, the problem of volume expansion caused by the icing of the liquid in the nozzle in a low-temperature environment needs to be considered.

Disclosure of Invention

The present application is directed to the above-mentioned problems, and an object of the present application is to provide an anti-freezing type post-treatment liquid nozzle which has a simple structure, good environmental adaptability, and is easy to install.

In order to achieve the purpose, the invention adopts the following technical scheme: an anti-freezing type after-treatment liquid nozzle comprises a solenoid liquid supply device, a reducing agent nozzle, a cooling water jacket and a nozzle fixing bracket.

The reducing agent nozzle comprises an injection part and a liquid cavity, wherein the liquid cavity is a space which is limited by elastic pretightening force and can be repeatedly expanded and restored, the space is formed by connecting a solenoid liquid supply device and the injection part, injection pressure generated by the controlled movement of the injection part firstly acts on liquid in the space, and then high-pressure liquid is sprayed out from a nozzle port. The solenoid liquid supply device and the injection part are sealed through a sealing piece, the sealing piece is 0 circle in the axial direction, an independent sealing space is formed, and the stability of a liquid environment is guaranteed.

Furthermore, the solenoid liquid supply device and the injection part are connected and fixed by an elastic piece in a pre-tightening way, when the pressure in the liquid cavity is within a normal working pressure range, the elastic piece pre-tightening connection cannot be further deformed, but if the pressure in the liquid cavity exceeds the maximum design normal pressure, the elastic piece pre-tightening connection can be further deformed, so that the solenoid liquid supply device and the injection part are relatively displaced to cause the volume of the liquid cavity to be changed, further increase of the internal pressure is limited, the weak parts of the cavity are prevented from being failed, and when the internal pressure is reduced to be below the maximum design normal pressure, all deformation and the volume are completely restored to the original state.

The elastic piece and the nozzle fixing support are integrated, and the nozzle fixing support enables the solenoid liquid supply device and the spraying part to be fixed on the cooling water sleeve.

The cooling water jacket comprises a liquid nozzle mounting hole, a cooling water cavity coaxial with the nozzle mounting hole, a water inlet channel and a water outlet channel, wherein the spraying part of the nozzle is mounted in the nozzle mounting hole and fixed through a nozzle fixing support, cooling liquid in the cooling water cavity surrounds the spraying part, enters from the water inlet channel, is output from the water outlet channel and circulates, and therefore the nozzle and the sealing element are protected from being damaged by high temperature.

The ejection portion includes an outwardly opening nozzle from which liquid is output when the liquid chamber pressure is higher than an opening pressure of the outwardly opening nozzle. When the liquid freezing device is in a non-working state, if low-temperature liquid freezes, the volume of the liquid cavity is changed through the deformation of the elastic piece, and the requirement of freezing and expansion of the liquid is met.

The following technical solutions further define or optimize the present application.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of an anti-freezing post-treatment liquid nozzle provided by the present invention.

Fig. 2 is a schematic diagram of a liquid chamber of an anti-freezing type post-treatment liquid nozzle provided by the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.

The freeze resistant aftertreatment liquid nozzle provided herein, as shown in FIG. 1, includes a solenoid supply 109, a reductant nozzle 108, a cooling jacket 100, a nozzle mount bracket 112, a nozzle mount 106, and a nozzle mount gasket 101.

The reducing agent nozzle 108 includes an injection portion 107 and a liquid chamber 211, and the liquid chamber 211 is schematically shown in fig. 2, is an elastic space, is formed by connecting the solenoid liquid supply device 109 and the injection portion 107, and stores pressure liquid for the injection portion 107.

The solenoid liquid supply device 109 comprises a metal sleeve 215, the metal sleeve 215 comprises a U-shaped cavity 210 and a bottom step 214, the spraying part 107 comprises an outward opening nozzle 211 and a limiting surface 212, and the bottom step 214 and the limiting surface 212 are matched and pressed to form a working volume of the liquid cavity 211. The solenoid liquid supply device 109 and the injection part 107 are sealed by an axial sealing element 213 which can slide axially, so as to form an independent sealing space and ensure the stability of the liquid environment. Seal 213 is an axial sealing O-ring.

Further, the solenoid liquid supply device 109 and the injection part 107 are fixed by an elastic element 216 and have a certain pre-tightening force within an elastic range, and during normal injection, the axial separation force of the pressure in the liquid cavity 211 on the solenoid liquid supply device 109 and the injection part 107 is smaller than the pre-tightening force generated by the elastic element 216, so that the working volume of the liquid cavity 211 cannot be changed. However, when the liquid in the liquid chamber 211 freezes and expands due to the low ambient temperature during the placing process, the pressure in the liquid chamber 211 may rise to the pre-tightening force generated by the elastic member 216, so that the solenoid liquid supply device 109 and the injection part 107 may axially separate from each other, but the axial sealing O-ring seal 213 still can ensure the sealing of the two, and the volume of the liquid chamber 211 changes accordingly, thereby limiting the further rise of the pressure in the liquid chamber 211, and preventing the weak parts of the chamber from being damaged and failed due to the high pressure, which failure may cause the nozzle to work improperly after being thawed, or cause the working liquid to leak out, for example, to be cooperated with the outside of the cooling water chamber or the nozzle, and affect the vehicle cooling system function and the urea liquid injection function. When the nozzle of the structure of the invention is thawed, the interior ice is melted, the volume is contracted, the pressure in the liquid cavity 211 is reduced to normal pressure, the pretightening force generated by the elastic element 216 enables the solenoid liquid supply device 109 and the spraying part 107 to restore to the original position and the retaining force, and the nozzle restores and maintains the original normal state without damage or leakage failure.

The elastic member 216 may be integrally provided with the nozzle fixing bracket 112, and the nozzle fixing bracket 112 is fixed to the cooling water jacket 100 such that the solenoid liquid supply device 109 and the injection portion 107 are integrally fixed.

The cooling water jacket 100 comprises a nozzle mounting hole 116, a nozzle fixing threaded hole 114, a cooling water cavity 200 coaxial with the nozzle mounting hole 116, and a water inlet pipe 113 and a water outlet pipe 118 which are communicated with the cooling water cavity 200.

The nozzle fixing bracket 112 is used for mounting and fixing the reducing agent nozzle 108, and the nozzle fixing bracket 112 is in an inverted U shape and includes two lip eaves 110 with fixing holes 110 a. The injection part 107 of the reducing agent nozzle 108 extends into the nozzle mounting hole 116, the solenoid liquid supply device 109 is partially positioned at the upper end of the cooling water jacket 100, the reducing agent nozzle 108 is fastened by the nozzle fixing bracket 112, the bottom surface 110b of the lip 110 is tightly attached to the threaded hole plane 114a of the cooling water jacket 100, the fixing bolt 111 passes through the fixing hole 110a and is locked in the nozzle fixing threaded hole 114, so that the reducing agent nozzle 108 is mounted and fixed on the cooling water jacket 100.

In addition, the nozzle mount 106 is used for mounting the anti-freezing type aftertreatment liquid nozzle to an engine exhaust pipe (not shown), and the nozzle mount 106 may be designed as a single body with the cooling water jacket 100, and formed by integral machining or injection molding. The nozzle mount 106 includes a positioning hole 105 and a ring groove 104. The nozzle mounting pad 101 may be stamped from a sheet of metal and includes a snap 103, a raised rim 102. The buckle 103 comprises a raised elastic sheet 103a, the buckle 103 is pressed into the nozzle mounting seat 106, and the elastic sheet 103a is buckled into the annular groove 104. The reducing agent nozzle 108 is mounted on the exhaust pipe (not shown) through the positioning hole 105 and tightened by the bolts 117, so that the annular edge 102 is tightly attached to the bottom surface of the reducing agent nozzle 108, thereby forming a sealing surface, and in order to ensure uniform stress, at least two bolts 117 are distributed uniformly in the circumferential direction (the rest are not shown).

In normal operation, the solenoid liquid supply device 109 receives an operation signal and generates a fixed amount of pressure solution to enter the liquid chamber 211, and when the pressure of the liquid chamber 211 is higher than the opening pressure of the outward opening nozzle 211, the liquid is output from the ejection portion 107.

In this process, the engine cooling water is in circulation for cooling the aftertreatment liquid nozzle. The cooling water enters from the water inlet pipe 113, passes through the cooling water cavity 200, and is output from the water outlet pipe 118 to circulate, and the cooling liquid in the cooling water cavity 200 surrounds the injection part 107, so that the reducing agent nozzle 108 is protected from being damaged by high temperature. The reducing agent nozzle 108 and the cooling water jacket 100 are sealed by a sealing element 115 to prevent the cooling water solution from leaking, and the sealing element 115 can resist the temperature of 300 ℃ and above.

The injection part 107 is made of a metal material, and ensures that the reducing agent nozzle 108 can still work normally when the cooling water does not work. For example, in a high-temperature shutdown state, the temperature of water in the cooling water cavity 200 is relatively increased, and at this time, the reducing agent nozzle 108 is designed to be resistant to high temperature, so as to avoid high-temperature damage. Throughout the process, the temperature of the injection portion 107 of the reducing agent nozzle 108 is lower than the temperature of the liquid in the cooling water chamber 200.

However, when the engine system stops working, part of the working liquid is retained in the pipeline, the residual solution freezes in a low-temperature environment, the temperature of the reducing agent nozzle 108 is slowly reduced due to the heat preservation effect of the cooling water, the freezing speed of the solution in the liquid cavity 211 is lower than that of the surrounding liquid, and finally, no liquid flows out from the surrounding area during freezing and only can expand, so that the pressure in the liquid cavity 211 is increased, and the volume of the liquid cavity 211 can be increased due to elastic deformation generated by the elastic element 216, so that the volume requirement of liquid freezing and expanding is met, further increase of the pressure in the cavity is limited, the nozzle is protected from being damaged, and the elastic deformation restores to the original position when the frozen liquid melts.

The above examples are only for illustrating the essence of the present invention, but not for limiting the present invention. Any modifications, simplifications, or other alternatives made without departing from the principles of the invention are intended to be included within the scope of the invention.

The present invention is not concerned with parts which are the same as or can be implemented using prior art techniques.

Claims (7)

1. An anti-freezing type after-treatment liquid nozzle comprises a solenoid liquid supply device, a reducing agent nozzle, a cooling water jacket and a nozzle fixing bracket, and is characterized in that the reducing agent nozzle comprises an injection part and a liquid cavity, and the liquid cavity is a space which is limited by elastic pretightening force and can be repeatedly expanded and restored.

2. The freeze-resistant aftertreatment liquid nozzle of claim 1, wherein the liquid chamber is a liquid space defined by the connection of the solenoid supply and the spray portion, and the spray pressure generated by the controlled movement of the spray portion is applied to the liquid in the space first, and then the high pressure liquid is sprayed from the nozzle port.

3. The freeze-resistant aftertreatment liquid spray nozzle of claim 2 wherein the solenoid supply and spray sections are secured in a pre-tensioned connection by a resilient member which is not further deformed when the pressure in the liquid chamber is within the normal operating pressure range but which is further deformed if the pressure in the liquid chamber exceeds the maximum design normal pressure, causing relative displacement of the solenoid supply and spray sections which results in a change in the volume of the liquid chamber thereby limiting further increase in internal pressure to prevent failure of chamber weaknesses and allowing full recovery of all deformation and volume to the original condition when the internal pressure drops below the maximum design normal pressure.

4. The freeze-resistant aftertreatment liquid spray nozzle of claim 3 wherein the solenoid supply and the spray tip are sealed by an axial O-ring seal.

5. The freeze-resistant aftertreatment liquid nozzle of claim 4, wherein the resilient member is integrally provided with the nozzle mount bracket.

6. The freeze-resistant aftertreatment liquid nozzle of claim 5, wherein the nozzle mount bracket secures the solenoid supply and the spray tip to the cooling jacket.

7. The freeze-resistant aftertreatment liquid nozzle of any one of claims 1 to 6, wherein the cooling jacket includes a liquid nozzle mounting hole, a cooling water chamber coaxial with the nozzle mounting hole, an inlet channel and an outlet channel, the spray portion of the nozzle being mounted in the nozzle mounting hole and fixed by the nozzle fixing bracket, and cooling liquid in the cooling water chamber circulates around the spray portion, entering from the inlet channel and exiting from the outlet channel, thereby protecting the nozzle and the sealing member from high temperature damage.

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