CN210343455U

CN210343455U - High-temperature-resistant electric liquid metering nozzle

Info

Publication number: CN210343455U
Application number: CN201821890005.6U
Authority: CN
Inventors: 徐露明; 张平; 乐起奖; 谈秉乾
Original assignee: Fuai Electronics Guizhou Co ltd
Current assignee: Fuai Electronics Guizhou Co ltd
Priority date: 2018-11-16
Filing date: 2018-11-16
Publication date: 2020-04-17
Anticipated expiration: 2028-11-16

Abstract

The utility model provides a high temperature resistance electronic liquid metering nozzle, including electromagnetic drive device, the feed liquor valve, the plunger, the sleeve, go out the liquid valve, from open nozzle, the feed liquor connector, go out the liquid connector, the cooling water course, the cooling water connector, a serial communication port, be provided with plunger compression volume stop gear on the sleeve, the plunger is fixed for telescopic motion stroke size, the volume change that every pulse produced equals, liquid in the compression volume that plunger and sleeve formed is under the effect of the drive force that electromagnetic drive device pulse adds the electricity and produce, compressed output is to from open nozzle, the nozzle is opened under the effect of liquid pressure and is atomized liquid blowout, the cooling water course sets up at the front end position that is close to from open nozzle as far as possible.

Description

High-temperature-resistant electric liquid metering nozzle

Technical Field

The invention belongs to the field of engine emission control, and particularly relates to a Selective Catalytic Reduction (SCR) system for purifying NOx in engine tail gas.

Background

The liquid jet metering has wide application in the fields of chemical engineering, medical treatment, power machinery and the like, and particularly relates to a plurality of core technologies of internal combustion engine power. For example, in a diesel engine or a lean-burn gasoline direct injection engine, in order to reduce harmful pollutants in exhaust gas, a Selective Catalytic Reduction (SCR) technique capable of performing Catalytic Reduction treatment in an oxygen-rich environment is used for NOx pollutants. For the Particulate matter emission of a Diesel engine, a Diesel Particulate Filter (DPF) technology or the like is used.

The SCR technology requires that, for example, a urea aqueous solution (also called Diesel Exhaust Fluid DEF or additive blue AdBlue) having a concentration of 32.5% by weight is injected into Diesel Exhaust gas in a fixed amount, decomposed into ammonia gas at a high temperature of the Exhaust gas, mixed with the Exhaust gas, and then introduced into an SCR catalytic converter. Under the action of catalyst, ammonia gas and NOx in engine exhaust gas produce catalytic reduction reaction to decompose NOx into harmless N₂、H₂And O. If the DEF injection amount does not match the NOx content in the exhaust gas, either NOx cannot be sufficiently reductively decomposed and the amount of emission increases, or a large amount of remaining ammonia is discharged to the atmosphere, causing secondary pollution. Therefore, the SCR system necessarily needs an SCR metering injection device with high precision and an injection solution with good atomization effect. Therefore, the manner of mounting the nozzle on the exhaust pipe is widely adopted due to advantages such as its injection accuracy, flexibility, wide adaptability, and low cost.

However, the exhaust pipe mounting scheme has a high selectivity to the nozzle itself. Firstly, the high temperature of the exhaust gas may cause the chemical change of the nozzle to generate crystals, thereby causing serious consequences such as pipeline blockage or nozzle failure.

In addition, due to the characteristics of the urea aqueous solution, after the injection is finished, the urea mixed solution remained in the closed urea system and the pipeline is likely to freeze below the freezing point (-11-12 ℃) of the urea solution, which not only can cause the interruption of the urea injection, but also can cause the damage of the metering nozzle due to the expansion of the urea solution during the freezing.

In conclusion, it is an important research subject to solve the problems of nozzle damage caused by high exhaust temperature and nozzle failure caused by icing and expansion of residual solution in the exhaust aftertreatment system by the prior art. It is also necessary to provide a new technical scheme with simple structure, high reliability and convenient application.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electromotive liquid metering nozzle which is simple in structure, good in adaptability, and high in reliability.

In order to achieve the purpose, the invention adopts the following technical scheme: a high-temperature-resistant electric liquid metering nozzle comprises an electromagnetic driving device, a plunger assembly, a self-opening nozzle, a liquid inlet connector and a liquid return connector.

The electromagnetic drive device includes a solenoid device, a yoke formed of a magnetically permeable material, and a magnetic resistance formed of a magnetically non-permeable material. The plunger assembly comprises a sleeve, a plunger which is precisely matched with the sleeve and can move relatively, a liquid inlet valve, a liquid outlet valve and a return spring. The liquid inlet valve is arranged at one end of the sleeve, the liquid outlet valve is arranged at one end of the plunger, and the sleeve, the plunger, the liquid inlet valve and the liquid outlet valve form a pressure conveying space. The working liquid enters from the liquid inlet connector and is filled into the liquid space of the whole metering nozzle through the liquid inlet valve, the sleeve of the plunger assembly is acted by the electromagnetic force of the electromagnetic driving device and the spring force of the return spring to cause the volume of the pressure feeding space to be changed alternately, so that high-pressure working liquid is generated, the liquid enters the self-opening nozzle through the liquid outlet valve and is then sprayed out to an exhaust pipe of an engine, and return liquid generated by the movement of the sleeve flows back to the urea tank through the liquid return connector.

The self-opening nozzle is a lift valve type nozzle and comprises a nozzle valve body, a nozzle valve rod and a nozzle valve spring, the nozzle valve body and the nozzle valve rod are matched to form a pressure chamber, and when the pressure of the pressure chamber is higher than the preset spring force of the nozzle valve spring, the nozzle is opened.

Further, the self-opening nozzle also comprises a nozzle cooling device and a nozzle anti-freezing device. The nozzle cooling device can be a circulating water cooling device and comprises a cooling water channel and a cooling water connecting nozzle, the cooling water channel is arranged around the front end of the self-opening nozzle, the cooling water connecting nozzle is connected to an engine cooling water loop, and the self-opening nozzle body takes away heat through circulation of engine cooling water so as to protect the nozzle from being damaged by high exhaust temperature. The nozzle anti-freezing device is an anti-freezing space arranged in the pressure chamber and used for providing space requirements for liquid generated due to expansion in a low-temperature environment and preventing the nozzle from being frozen and cracked to lose efficacy. The anti-freezing space can be a thin-wall metal cavity with enough surface area, and the requirement of the liquid expansion space is met through the elastic deformation of the cavity.

The nozzle cooling means may also be a heat exchanger, e.g. a fin arrangement, arranged at the front end of the nozzle to carry the heat of the nozzle to the atmosphere by means of heat convection and heat radiation.

Further, the plunger assembly of the electrically operated liquid metering nozzle includes a pumping space volume limiting mechanism. The pressure feeding space volume limiting mechanism is arranged at the tail end of the reciprocating stroke of the sleeve and comprises an upper pump end and a lower pump end, the sleeve reciprocates in a fixed stroke under the action of electromagnetic force and reset spring force, so that the volume of the pressure feeding space is periodically changed, and the liquid injection amount generated by each pulse is equal.

The high-temperature-resistant electric liquid metering nozzle further comprises a mounting seat with a positioning hole and a nozzle gasket, the nozzle gasket comprises a protrusion flatly attached to the bottom plane of the metering nozzle, the metering nozzle is fixed through the mounting seat and locked on the exhaust pipe through a bolt, and the protrusion of the nozzle gasket deforms and clings to the metering nozzle after being locked, so that sealing is achieved.

An SCR system applies the high-temperature-resistant electric liquid metering nozzle and further comprises a urea box, a supply module and a supply pump. The supply module comprises a liquid outlet nozzle and a liquid return nozzle, the liquid outlet nozzle is connected to the liquid inlet connector of the liquid metering nozzle through a liquid supply pipe, and the liquid return nozzle is connected to the liquid return connector of the liquid metering nozzle through a liquid return pipe. The supply module comprises a bracket, and the liquid supply pump penetrates into the bottom position of the urea box through the bracket. The pressure liquid generated by the supply pump is conveyed to the metering nozzle through the module liquid outlet nozzle and the liquid supply pipe. The branch and add and be integrated with an ice-melt device, for example engine coolant liquid circulating pipe to guarantee the normal work of module when low temperature environment.

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

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of a high temperature resistant electric liquid metering nozzle provided by the present invention.

FIG. 2 is a second schematic structural diagram of an embodiment of a high temperature resistant electric liquid metering nozzle provided by the present invention.

FIG. 3 is a schematic view of a gasket structure of the metering nozzle provided in the present invention.

FIG. 4 is a schematic view of an exemplary embodiment of a high temperature resistant electric liquid metering nozzle.

Detailed Description

The invention is further described below with reference to the figures and examples.

Fig. 1 is a schematic structural diagram of a first embodiment of the present invention, which includes an electromagnetic driving device 2, a sleeve 20 assembly 4, a self-opening nozzle 3, a liquid inlet nozzle 10, and a liquid return nozzle 21.

The electromagnetic drive device 2 comprises a solenoid device 11, a yoke 13 and a magnetic resistance 12, wherein the yoke 13 is made of a magnetic conductive material, and the magnetic resistance 12 is made of a non-magnetic conductive material. The sleeve 20 assembly 4 comprises a sleeve 29, a sleeve 20 which is precisely matched with the sleeve 29 and can move relatively, an inlet valve 31, an outlet valve 32 and a return spring 23. The liquid inlet valve 31 is arranged at one end of the sleeve 29 and comprises an oil inlet valve member 27, an oil inlet valve seat 28 and an oil inlet valve spring 26, the liquid outlet valve 32 is arranged at one end of the sleeve 20 and comprises an oil outlet valve member 24, an oil outlet valve seat 25 and an oil outlet valve spring 23, and the valve members (27 or 24) and the conical surfaces of the valve seats (28 or 25) are correspondingly matched to form a sealing mechanism. The sleeve 29, the sleeve 20, the inlet valve 31 and the outlet valve 32 form a pressure feed space 33. The working liquid enters from the liquid inlet connector 10 and is filled into the liquid space of the whole metering nozzle 1 through the liquid inlet valve 31, the sleeve 29 of the sleeve 20 component 4 is acted by the electromagnetic force of the electromagnetic driving device 2 and the spring force of the return spring 23, so that the volume of the pressure feeding space 33 is changed alternately, high-pressure working liquid is generated, and the liquid enters the self-opening nozzle 3 through the liquid outlet valve 32 and is sprayed into an exhaust pipe of an engine. The liquid return connector 21 comprises a liquid return channel 22, the liquid return channel 22 is communicated with the sleeve movement volume cavity 34, and return liquid generated by the movement of the sleeve 29 flows back to the urea box 7 through the liquid return connector 21. The sleeve 29 includes straight grooves 29a arranged in alternate axial directions to reduce resistance to reciprocating movement.

The cartridge 20 assembly 4 of the electric liquid metering nozzle 1 includes a volume limiting mechanism (35, 36) for the pumping space 33. The volume limiting mechanisms (35, 36) of the pressure feeding space 33 are arranged at the end of the reciprocating stroke of the sleeve 29 and comprise an upper pump end 35 and a lower pump end 36, the sleeve 29 performs reciprocating motion with a fixed stroke under the action of electromagnetic force and the force of the return spring 23, the volume of the pressure feeding space 33 is periodically changed, and the liquid injection quantity generated by each pulse is equal. The upper pump end 35 includes a limit boss 30 for the oil inlet valve 27 to ensure that the oil inlet valve remains open at the end of the movement stroke of the sleeve 29, so that the supply working fluid can smoothly enter the pump body.

The self-opening nozzle 3 is a poppet nozzle and comprises a nozzle valve body 15, a nozzle valve rod 18 and a nozzle valve spring 16, wherein the nozzle valve body 15 and the nozzle valve rod 18 are matched to form a pressure chamber, and the nozzle is opened when the pressure of the pressure chamber is higher than the preset spring force of the nozzle valve spring 16.

Further, the self-opening nozzle 3 further comprises a nozzle cooling device 5, a nozzle anti-freezing device 6 and a filter screen structure 19. Nozzle cooling device 5 is a circulating water-cooling device, including a cooling water course 37 and cooling water connector 14, cooling water course 37 encircles and arranges from 3 front ends of open nozzle, and cooling water connector 14 is connected to engine cooling water return circuit, takes away the heat from 3 bodies of open nozzle through engine cooling water circulation to protection nozzle 3 does not receive exhaust high temperature to damage. The anti-freezing device 6 of the nozzle 3 is an anti-freezing space 17 arranged in the pressure chamber and used for providing space requirements for liquid generated by expansion in a low-temperature environment and preventing the nozzle from being frozen and cracked to fail. The freeze resistant space 17 may be a thin-walled metal cavity of sufficient surface area to meet the liquid expansion space requirements through elastic deformation of the cavity. The filter screen structure 19 is arranged at the liquid inlet end position of the nozzle, and high-pressure liquid enters the pressure chamber of the self-opening nozzle 3 after being filtered by the filter screen 19 so as to prevent liquid dirt from blocking the nozzle.

The high temperature resistant electric liquid metering nozzle 1 further comprises a nozzle gasket 13, as shown in fig. 3, the nozzle gasket 13 comprises a protrusion 310 flatly attached to the bottom plane 38 of the metering nozzle 1, and the metering nozzle 1 is sealed by the protrusion 310 of the gasket deforming and clinging to the bottom plane 38. The nozzle gasket 13 is mounted to the bottom of the metering nozzle 1 by means of a hook 311.

Fig. 2 is a schematic structural diagram of a second embodiment of the present invention, which is different from the first embodiment of the present invention in that: the nozzle cooling device 5 is a heat exchanger 210 arranged at the front end of the nozzle 3, and the heat exchanger 210 is a cooling fin device which brings the heat of the nozzle to the atmosphere by means of convective heat transfer and heat radiation.

Fig. 4 is a schematic structural diagram of an application example provided by the present invention, which includes a urea tank 7, a urea supply pump 401, a high temperature-resistant electric liquid metering nozzle 1, a module 9 body 9, a urea liquid level sensor 424, a urea liquid temperature sensor 425, a urea liquid quality sensor 419, a urea liquid heating and thawing circulation water pipe 426, and a urea cleaning device 403.

The module 9 is provided with a urea liquid outlet nozzle 436, a liquid return nozzle 435, water inlet and outlet nozzles (442, 443) of the heating and thawing circulating water pipe 426 on the body 9, a secondary urea liquid filtering device 406 arranged at the upstream of the liquid outlet nozzle 436, and a mounting buckle 405 for mounting and fixing the module 9 to the urea tank 7 after inserting the module 9 into the urea tank 7 from the upper part of the urea tank 7. One end of the liquid outlet nozzle 436 is connected to the liquid inlet nozzle 10 of the liquid metering nozzle 1 through a liquid supply pipe 445, and one end of the liquid return nozzle 435 is connected to the liquid return nozzle 21 of the liquid metering nozzle 1 through a liquid return pipe 444. In addition, the body 9 of the module 9 itself includes an internal liquid outlet channel 447, a liquid return channel 446 and an axial array of trapezoidal steps 429. The other end of the liquid return nozzle 435 is communicated with a liquid return channel 446, and is communicated with the interior of the urea box 7 to a certain depth through the liquid return channel 446. The mounting buckle 405 comprises a limiting hole 432a matched with a step of the module 9 body 9, a protrusion 432 matched with a mounting limiting step 431a of the urea tank 7 and a through hole allowing the urea solution to pass through each pipeline of the module 9, the mounting buckle 405 is fixed on the module 9 body 9 in a holding manner, and simultaneously limits each pipeline leading to the inside of the body and each sensor pipeline, so that the stability of each mounting component is ensured, and the module 9 is mounted in the mounting hole of the urea tank 7 through the protrusion 432.

Second stage urea filter 406 is positioned upstream of outlet nozzle 436 and includes a chamber 437a with a threaded cap 437b, and an inner cartridge 437 disposed within chamber 437 a. The cavity 437a is communicated with the internal liquid outlet channel 447, and the urea liquid is filtered by the filter element 437 and then output. The filter element 437 can be replaced regularly, and the filtering precision of the filter element 437 is higher than that of the primary filter screen 413, so that the normal work of the downstream metering nozzle 1 is ensured, and the service life of the system is prolonged.

The liquid supply pump 401 comprises an inlet 414 and an outlet 410, the inlet is provided with a primary filter screen 413, and the urea solution enters the liquid supply pump 401 after being filtered by the primary filter screen 413 under the action of self gravity. The primary screen 413 is secured to the feed pump 401 by a snap 405 and has a vertical exhaust bubble 447. In addition, a transverse air exhaust bubble tube 411 is arranged in the middle of the supply pump 401, and two air exhaust bubble tubes (447 and 411) are connected through a three-way connecting tube 422 and then lead to an air gap space above the bottom plane of the mounting buckle 405 of the module 9. The three-way connection pipe 422 is partially provided with a part of the primary filter screen 422a, so that when the urea solution is thawed after being frozen, the urea solution can be fed into the urea supply pump 401 through the part of the primary filter screen 422a which is thawed earliest.

The liquid outlet 410 is connected with a liquid outlet channel 447 inside the module body 9 through a liquid outlet pipe 427, the liquid outlet pipe 427 is a forming pipe and designed in a manner of being close to the heating and thawing circulating water pipe 426 as much as possible, a sealing gasket 446 is arranged between the liquid outlet pipe 427 and the liquid outlet channel 447 for sealing and damping, and the inside liquid outlet channel 447 leads to the liquid outlet nozzle 436.

The urea solution supply pump 401 and the urea solution quality sensor 419 are located at the bottom of the module 9, and are fixed on the urea solution heating and thawing circulating water pipe 426 so as to be arranged in a manner of being beneficial to thawing ice. The urea liquid heating and thawing circulating water pipe 426 is a bottom L-shaped pipe 418, and a platform 415 with a positioning hole 416 is arranged between the L-shaped pipes 418, so that the urea supply pump 401 and the urea liquid quality sensor 419 are fixed at the same height position of the module 9, and can be inserted into the bottommost part of the urea tank 7 through a module mounting hole 431 of the urea tank 7. The quality sensor 419 includes a threaded hole 421a and a step 421 corresponding to the positioning hole 416, and is fixed on the platform 415 by a bolt 417. The urea level sensor 424 and the urea temperature sensor 425 are fixed by the module 9 and extend into the urea tank 7 near the urea supply pump 401.

The metering nozzle 1 is mounted on the exhaust pipe 8 upstream of the SCR catalyst, locked and fixed to the exhaust pipe mounting block 449 by bolts 448.

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

1. The utility model provides a high temperature resistance electric liquid metering nozzle, includes electromagnetic drive device, plunger subassembly, connects mouth and returns liquid to connect the mouth from open nozzle, feed liquor, the plunger subassembly is driven by electromagnetic drive device electromagnetic force, produces high-pressure working fluid, and liquid is through from open nozzle blowout to engine exhaust pipe, its characterized in that: the self-opening nozzle comprises a nozzle cooling device and a nozzle anti-freezing device, wherein the nozzle cooling device is as close to the front end part of the self-opening nozzle as possible so as to protect the nozzle from being damaged by high exhaust temperature.

2. The high temperature resistant electric liquid metering nozzle of claim 1, wherein the self-opening nozzle comprises a pressure chamber, the nozzle anti-freezing device is a freezing resistant space arranged in the pressure chamber, and the liquid in the nozzle has enough expansion space when frozen ice at low temperature, so that the nozzle cannot be burst and damaged due to ice.

3. The high temperature resistant electric liquid metering nozzle of claim 2, wherein: the nozzle cooling device is a circulating water cooling device and comprises a cooling water channel and a cooling water connector, wherein the cooling water channel is arranged around the front end of the self-opening nozzle.

4. The high temperature resistant electric liquid metering nozzle of claim 2, wherein: the nozzle cooling device comprises a heat exchanger arranged at the front end of the nozzle, and the heat of the nozzle is brought into the atmosphere by means of convective heat exchange and heat radiation.

5. The high temperature resistant electric liquid metering nozzle of claim 3 or 4, characterized by: the plunger assembly comprises a liquid inlet valve, a plunger, a sleeve and a liquid outlet valve, the liquid inlet valve, the liquid outlet valve, the plunger and the sleeve form a pressure conveying space, and the volume of the pressure conveying space is changed alternately due to the relative movement of the plunger and the sleeve.

6. The high temperature resistant electric liquid metering nozzle of claim 5, wherein: the plunger assembly is provided with a pressure feeding space volume limiting mechanism, the limiting mechanism is positioned at the tail end of the reciprocating stroke of the sleeve and is an upper pump end and a lower pump end respectively, so that the movement stroke of the sleeve relative to the plunger is fixed, and the volume change generated by each pulse is equal.

7. The high temperature resistant electric liquid metering nozzle of claim 6, wherein: the nozzle gasket comprises a mounting seat with a positioning hole and a nozzle gasket, the nozzle gasket comprises a protrusion which is flatly attached to the bottom plane of the metering nozzle, the metering nozzle is fixed through the mounting seat and locked on the exhaust pipe through a bolt, and the protrusion of the nozzle gasket deforms and clings to the metering nozzle after being locked, so that sealing is realized.

8. An SCR system using the high temperature resistant electric liquid metering nozzle of claim 7, characterized in that: including a urea case, a supply module, a delivery pump, supply the module and include a drain nozzle and a liquid return nozzle, the feed liquor of liquid measurement nozzle connects the mouth to the drain nozzle, the liquid return nozzle of liquid measurement nozzle is connected to the liquid return nozzle.

9. The SCR system of claim 8, wherein: the supply module comprises a bracket, and the supply pump extends into the bottom position of the urea box through the bracket and provides pressure liquid for the liquid metering nozzle.