WO2018077005A1

WO2018077005A1 - Urea tube having one-way throttling function, urea spraying system and control method therefor

Info

Publication number: WO2018077005A1
Application number: PCT/CN2017/104329
Authority: WO
Inventors: 童毅; 孙树平; 王飞; 李敏; 杨慧敏
Original assignee: 天纳克（苏州）排放系统有限公司
Priority date: 2016-10-26
Filing date: 2017-09-29
Publication date: 2018-05-03
Also published as: CN106285864A

Abstract

A urea tube (100) having a one-way throttling function, comprising a quick connector plug (1), a urea outlet connector (2) in communication with the quick connector plug (1), and a bypass tube assembly (3) in communication with the urea outlet connector (2). The bypass tube assembly (3) comprises a urea-resistant nylon tube (31), a resistance wire (32) wound around the urea-resistant nylon tube (31) and used for heating the urea-resistant nylon tube (31), a thermally conductive layer (33) located at the periphery of the resistive wire (32) and used for defining the resistance wire (32), a thermal insulation layer (34) wrapped around the thermally conductive layer (33), and a corrugated sleeve (35) wrapped around the thermal insulation layer (34). A one-way throttle (36) is mounted in the bypass tube assembly (3). Further provided are a urea spraying system and a control method therefor. The urea tube (100) having a one-way throttling function can return urea to a urea tank (300) when the system pressure is high, so as to protect a urea pump. Moreover, the present invention has a reverse blocking function when a gear pump pumps in a reverse direction, so that the urea in a urea pressure tube can flow back to the urea tank.

Description

Urea tube with one-way throttling function, urea injection system and control method thereof

The present application claims the priority of the Chinese patent application whose application date is October 26, 2016, the application number is 201610948316.2, and the invention name is "the urea pipe having the one-way throttling function, the urea injection system, and the control method thereof". The entire contents are incorporated herein by reference.

Technical field

The invention relates to a urea pipe with a one-way throttling function, a urea injection system and a control method thereof, and belongs to the technical field of engine exhaust gas post-treatment.

Background technique

Existing urea injection systems typically include a urea pump assembly to extract a urea solution from a urea tank and a urea nozzle to inject urea into the exhaust of the engine. Based on the current urea pump assembly in operation, the pump is continuously operated to supply urea, and the water-cooled nozzle used is not provided with a structure for cooling the reflux of urea. When the nozzle is not open, the urea pumped from the urea pump cannot be recirculated, causing the urea pump to overflow and will damage the urea pump.

Summary of the invention

It is an object of the present invention to provide a urea pipe having a one-way throttling function, a urea injection system, and a control method therefor.

In order to achieve the above object, the present invention adopts the following technical solution: a urea pipe having a one-way throttling function, comprising a quick connect plug, a urea outlet joint communicating with the quick connect plug, and connected to the urea outlet joint a bypass pipe assembly comprising a urea-resistant nylon tube, a resistance wire wound on the urea-resistant nylon tube and used to heat the urea-resistant nylon tube, located at a periphery of the resistance wire a heat conducting layer for defining the electric resistance wire, an insulating layer wrapped around a periphery of the heat conducting layer, and a corrugated sheath wrapped around a periphery of the heat insulating layer, wherein the bypass pipe assembly is provided with a one-way throttle valve.

As a further improved technical solution of the present invention, the quick-connect plug is provided with an inlet pipe portion aligned with the urea outlet joint and an outlet pipe portion connected between the inlet pipe portion and the urea outlet joint, wherein The outlet tube portion is inserted into the urea-resistant nylon tube.

As a further improved technical solution of the present invention, the one-way throttle valve is also inserted in the urea-resistant nylon tube and located downstream of the outlet pipe portion.

As a further improved technical solution of the present invention, the heat conductive layer comprises tin foil paper.

As a further improved technical solution of the present invention, the urea pipe further includes an injection molded part wrapped around the inlet pipe portion, the outlet pipe portion, and at least a portion of the periphery of the bypass pipe assembly.

The present invention also discloses a urea injection system comprising a urea pump assembly for extracting a urea solution from a urea tank and a urea nozzle for injecting urea into the exhaust gas of the engine, the urea injection system further comprising the aforementioned a urea tube, wherein the quick connect plug is in communication with the urea pump assembly, the bypass tube assembly is in communication with the urea tank, and the urea outlet joint is in communication with the urea nozzle.

As a further improved technical solution of the present invention, the urea pump assembly includes a gear pump capable of operating in forward and reverse directions.

The invention also discloses a control method of a urea injection system, which comprises the following steps:

S1, when the urea pump assembly starts to work, opening the urea nozzle; when the system pressure reaches a set value, closing the urea nozzle; when the urea pressure from the urea pump assembly reaches the one-way When the opening pressure of the throttle valve is opened, the one-way throttle valve is opened to return at least part of the urea to the urea tank;

S2, when the urea pump assembly is working normally, a part of urea from the gear pump is sprayed from the urea nozzle, and excess urea flows back from the bypass pipe assembly to the urea tank;

S3, when the gear pump is reversed and pumped back, the urea nozzle is opened, urea in the bypass pipe assembly is reversely closed by the one-way throttle valve, and urea in the urea pressure pipe passes through the gear The pump is returned to the urea tank.

Compared with the prior art, the invention can set the one-way throttle valve to return the urea to the urea tank when the system pressure is high, thereby protecting the urea pump; in addition, when the urea pump is pumped back The reverse action is such that urea in the urea pressure tube can be refluxed into the urea tank.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a urea pipe having a one-way throttling function of the present invention.

Fig. 2 is a plan view showing the electric resistance wire of Fig. 1 removed.

Figure 3 is a cross-sectional view taken along line A-A of Figure 2;

Figure 4 is a partial enlarged view of the circled portion of Figure 3.

Figure 5 is a schematic diagram of the urea injection system of the present invention.

detailed description

Referring to Figures 1 to 4, the present invention discloses a urea tube 100 having a one-way throttling function. Figure 5 discloses a urea injection system 200 having the urea pipe 100, wherein the urea injection system 200 includes a urea pump assembly 400 for extracting a urea solution from the urea tank 300 and for exhausting to the engine A urea nozzle 500 that injects urea.

Referring to FIGS. 1 to 4 , the urea pipe 100 includes a quick connector plug 1 , a urea outlet connector 2 communicating with the quick connector plug 1 , and a bypass pipe assembly communicating with the urea outlet connector 2 . 3. The bypass pipe assembly 3 includes a urea-resistant nylon tube 31, a resistance wire 32 wound around the urea-resistant nylon tube 31 and used to heat the urea-resistant nylon tube 31, and is located at the periphery of the resistance wire 32. A heat conducting layer 33 defining the resistance wire 32, an insulating layer 34 wrapped around the heat conducting layer 33, and a corrugated sheath 35 wrapped around the periphery of the insulating layer 34 are defined. A one-way throttle valve 36 is mounted in the bypass pipe assembly 3.

Referring to FIG. 3 and FIG. 4, in the illustrated embodiment of the present invention, the quick-connect plug 1 is provided with an inlet pipe portion 11 aligned with the urea outlet joint 2 and connected to the inlet pipe portion 11 An outlet pipe portion 12 with the urea outlet joint 2. The outlet pipe portion 12 is inserted into the urea-resistant nylon tube 31. The one-way throttle valve 36 is also inserted in the urea-resistant nylon tube 31 and located downstream of the outlet tube portion 12, wherein the direction indicated by the arrow is the direction in which urea is normally recirculated.

The heat conducting layer comprises tin foil paper to prevent heat from escaping outward, improving the efficiency of heating and thawing.

The urea tube 100 further includes an injection molded part 4 wrapped around the inlet tube portion 11, the outlet tube portion 12, and at least a portion of the periphery of the bypass tube assembly 3.

Referring to FIG. 5, the quick connect plug 1 is in communication with the urea pump assembly 400. The bypass pipe assembly 3 is in communication with the urea tank 300. The urea outlet joint 2 is in communication with the urea nozzle 500. Preferably, the urea pump assembly 400 includes a gear pump that is capable of both forward and reverse operation.

The control method of the urea injection system 200 of the present invention comprises the following steps:

S1, when the urea pump assembly 400 starts to work, the urea nozzle 500 is opened; when the system pressure reaches a set value, the urea nozzle 500 is closed; when the urea pressure from the urea pump assembly 400 reaches When the pressure of the one-way throttle valve 36 is opened, the one-way throttle valve 36 is opened to return at least part of the urea into the urea tank 300;

S2, when the urea pump assembly 400 is operating normally, a portion of the urea from the gear pump is ejected from the urea nozzle 500, and excess urea flows from the bypass pipe assembly 3 back to the urea tank 300. ;

S3, when the gear pump is reversed and pumped back, the urea nozzle 500 is opened, and the urea in the bypass pipe assembly 3 is reversely closed by the one-way throttle valve 36, and the urea in the urea pressure pipe is reversed. The gear pump is recirculated into the urea tank 300.

By providing the one-way throttle valve 36, the present invention can return urea to the urea tank 300 when the system pressure is high, thereby protecting the urea pump. In addition, when the gear pump is reversed and retracted, it acts as a reverse end, so that urea in the urea pressure pipe can be refluxed into the urea tank 300.

In addition, the above embodiments are only for illustrating the present invention and are not intended to limit the technical solutions described in the present invention. The understanding of the present specification should be based on those skilled in the art, although the present specification has been carried out with reference to the above embodiments. DETAILED DESCRIPTION OF THE INVENTION However, those skilled in the art should understand that the invention may be modified or equivalently replaced by those skilled in the art without departing from the spirit and scope of the invention. It is intended to be included within the scope of the appended claims.

Claims

A urea tube having a one-way throttling function, comprising a quick connect plug, a urea outlet joint in communication with the quick connect plug, and a bypass tube assembly in communication with the urea outlet joint, wherein: The bypass pipe assembly includes a urea-resistant nylon tube, a resistance wire wound on the urea-resistant nylon tube and used to heat the urea-resistant nylon tube, a periphery of the resistance wire and used to define the resistance wire. a heat conducting layer, an insulating layer wrapped around the heat conducting layer, and a corrugated sheath wrapped around the periphery of the heat insulating layer, wherein the bypass pipe assembly is provided with a one-way throttle valve.
The urea pipe according to claim 1, wherein said quick-connect plug is provided with an inlet pipe portion aligned with said urea outlet joint and an outlet connected between said inlet pipe portion and said urea outlet joint a tube portion, wherein the outlet tube portion is inserted into the urea-resistant nylon tube.
The urea pipe according to claim 2, wherein said one-way throttle valve is also inserted in said urea-resistant nylon tube and located downstream of said outlet pipe portion.
The urea tube of claim 1 wherein said thermally conductive layer comprises tin foil paper.
A urea tube according to claim 3, wherein said urea tube further comprises an injection molded part wrapped around said inlet tube portion, said outlet tube portion and at least a portion of said bypass tube assembly.
A urea injection system comprising a urea pump assembly for extracting a urea solution from a urea tank and a urea nozzle for injecting urea into the exhaust gas of the engine, characterized in that the urea injection system further comprises the claims The urea pipe of any one of items 1 to 5, wherein the quick-connect plug is in communication with the urea pump assembly, the bypass pipe assembly is in communication with the urea tank, and the urea outlet joint is The urea nozzles are in communication.
The urea injection system of claim 6 wherein said urea pump assembly comprises a gear pump capable of both forward and reverse operation.
A method of controlling a urea injection system according to claim 7, comprising the steps of:

S1, when the urea pump assembly starts to work, opening the urea nozzle; when the system pressure reaches a set value, closing the urea nozzle; when the urea pressure from the urea pump assembly reaches the one-way When the opening pressure of the throttle valve is opened, the one-way throttle valve is opened to return at least part of the urea to the urea tank;

S2, when the urea pump assembly is working normally, a part of urea from the gear pump is sprayed from the urea nozzle, and excess urea flows back from the bypass pipe assembly to the urea tank;

S3, when the gear pump is reversed and pumped back, the urea nozzle is opened, urea in the bypass pipe assembly is reversely closed by the one-way throttle valve, and urea in the urea pressure pipe passes through the gear The pump is returned to the urea tank.