WO2012155292A1 - Integrated scr reducing agent storage device - Google Patents

Abstract

An integrated storage device for SCR reducing agent includes a liquid storage tank (2) and a metering injection unit (1), and also includes a transition plate (3) and a water heating unit (8). The liquid storage tank (2) is used for storing reducing agent; the metering injection unit (1) is integrated with the liquid storage tank (2) by the transition plate (3); the liquid storage tank (2) and the metering injection unit (1) are heated by the water heating unit (8). The integrated storage device for SCR reducing agent decreases pipelines and joints of the pipelines and the leakage risk of the reducing agent, and can control the injection of the reducing agent accurately.

Description

 Integrated SCR Reductant Storage Device Technical Field

 Say

 The invention relates to a storage and injection control device for a reducing agent in a diesel vehicle exhaust gas purification system, in particular to a reducing agent storage device in an integrated SCR (Selective Catalyst Reaction) system. Background technique

 With the increasing demands of the society for environmental protection, the state is increasingly on environmental protection. Relevant national authorities have issued relevant policies on motor vehicle emissions, especially the implementation of the "National IV Standard". Emission control is more stringent, and it is necessary to further reduce the pollutants by 30% to 50% on the basis of satisfying the book "National III Standard". The implementation process will be carried out according to the standard, and the "National IV Standard" will be implemented nationwide in 2012.

 It is known that Selective Catalytic Reduction (SCR) is the mainstream route for vehicle exhaust aftertreatment technology, that is, the reducing agent (called “Tianlan” in the industry) is injected into the exhaust line through atomization and is passed through SCR. The catalyst converts the main harmful gas NOX in the exhaust gas into nitrogen and water to achieve the purpose of exhaust gas purification, which is also the most common technical route to achieve the "National IV standard".

 The SCR system generally includes a urea tank, a metering jet pump, a nozzle, and the like. However, in the prior art, each of the above modular units is independent of each other, such as the one disclosed in CN101240729A, the name of the diesel vehicle exhaust and the urea tank reactor. As disclosed in the patent, the uric acid tank and the metering jet pump are connected by pipes and pipe joints. This often causes the following defects: First, each unit is independent of each other, and there are many pipelines (including pipelines such as liquid suction and liquid return). The arrangement is difficult, the pipeline connection is easy to be contaminated, the protection is difficult, and there are also hidden dangers.

 Second, the reducing agent in each pipeline is easy to freeze in a low temperature environment, and it is difficult to make ice. Third, the system cost is high, and the layout space required by each unit is large.

Fourth, in the actual loading, each unit is independent of each other. Because it is provided by different manufacturers, the matching effect is poor in the assembly, and all the units are installed and then connected by pipes, which is difficult to install and easy to be polluted. Summary of the invention

 SUMMARY OF THE INVENTION It is an object of the present invention to overcome the deficiencies of the prior art and to provide an integrated SCR reductant storage device that is highly integrated, compact in structure, easy to ice, and easy to maintain.

 In order to achieve the above object, the present invention provides the following technical solution: an integrated SCR reductant storage device, the integrated SCR reductant storage device includes a liquid storage tank and a metering spray unit, wherein the liquid storage tank is used for storing a reducing agent. The metering spray unit is integrated with the liquid storage tank.

 Preferably, the integrated SCR reductant storage device further includes a transition plate, and the metering injection unit is integrated with the liquid storage tank through a transition plate.

 The integrated SCR reductant storage device includes a water heating unit that heats the reservoir and metering spray unit.

 The metering and spraying unit further includes a cover body, a pump body, a diaphragm pump, a filter and a metering valve, wherein the cover body is fastened to the pump body, and a closed space is formed between the cover body and the pump body, at least The diaphragm pump is disposed in the enclosed space.

 The integrated SCR reductant storage device also includes a transition plate that is integrated with the reservoir through a transition plate.

 The metering spray unit includes a water heating unit that extends downwardly from the transition plate into the reservoir to heat the reservoir and metering spray unit.

 The water heating unit includes an inlet water inlet pipe, an outlet pipe, and a water circulation pipe disposed in the metering injection unit, the inlet pipe and the outlet pipe extending into the liquid storage tank.

 The water heating unit further includes a water inlet joint and a water outlet joint, wherein the water inlet joint and the water outlet joint are disposed on the pump body, and the water inlet joint, the water inlet pipe, the water outlet pipe, the water circulation pipe and the water outlet joint are connected .

 The integrated SCR reductant storage device further includes an inductive component disposed within the reservoir, the inductive component including a level sensor and a first temperature sensor.

 The inlet pipe is further provided with a heat insulation sleeve.

 A plurality of liquid flow conduits for circulating a reducing agent are formed in the pump body.

The metering injection unit further includes a first pressure sensor and a second pressure sensor disposed at both ends of the metering valve. The metering injection unit further includes a control unit electrically connecting the diaphragm pump and the metering valve to control injection of the reducing agent.

 The integrated SCR reductant storage device also includes a second temperature sensor disposed within the pump body.

 Compared with the prior art, the integrated SCR reducing agent storage device of the invention has the following advantages:

1) The design scheme is excellent and the integration is high;

 2) The pipetting and related pipe joints such as liquid suction, liquid return and heating pipe are omitted, which reduces the risk of reducing agent leakage;

 3) After heating, the engine cooling water directly passes through the metering pump and the liquid storage tank, saving water heating device or electric heating device for separately heating the metering pump;

 4) By heating the insulating sleeve on the upper part of the inlet pipe, the bottom reducing agent is heated first, and the heating effect is good, so that the reducing agent can be iced in time.

 5) The integrated structure of the metering pump and the urea tank has small space and low cost. At the same time, the modular installation is convenient for disassembly and installation, and the matching effect is good.

 6) The filter chamber is integrated with the voltage regulator cavity, which is compact in structure and good in voltage regulation effect, which is convenient for metering valve control.

 7) Adopting a cyclone mixing chamber, the pressure loss is small, the stirring and atomizing effect is good, and it is not easy to crystallize and block. DRAWINGS

 Figure 1 is a perspective view of the integrated SCR reducing agent storage device of the present invention;

 Figure 2 is a perspective exploded view of Figure 1;

 Figure 3 is a wiring diagram of the integrated SCR reducing agent storage device of the present invention;

 Figure 4 is an exploded perspective view of the filter of Figure 3;

 Figure 5 is a partial cross-sectional view showing the connection of the filter, metering valve and mixing chamber of the present invention;

 Figure 6 is a cross-sectional view taken along the line CC in Figure 5;

 Figure 7 is a bottom plan view of the pump body in the integrated SCR reducing agent storage device of the present invention;

 Figure 8 is a plan view of the pump body in the integrated SCR reducing agent storage device of the present invention;

 Figure 9 is a perspective view of the transition plate of the present invention;

Figure 10 is a wiring diagram of Embodiment 2 of the integrated SCR reducing agent storage device of the present invention; Figure 11 is a wiring diagram of Embodiment 3 of the integrated SCR reducing agent storage device of the present invention. The label of the component in the figure

 Metering spray unit 1 cover 11 pump body

 Lower surface of the pump body 121 Diaphragm pump 13 First pressure sensor Second pressure sensor 15 Flow line 16 Control unit

 Ring groove 161 tap fitting 18 sensing assembly

 Reservoir 2 transition plate 3

41 端盖 42 滤芯 43 进液口 44 出液口 45 计量阀

6 空气节流孔 61 单向阀 71 膜片阀 72 第一电磁阀 73 第三电磁阔 74 贯穿孔 75 喷嘴 76 排气管 77 通气管 79 水加热单元 8 进水接头 81 进水管 82 出水管 83 出水接头 84 水循环管道 85 第一流道 86 热交换器 87 隔热套 88 压縮空气单元 9 气源 91 第二电磁阀 92 减压阀 93 第二温度传感器 94 粗滤装置 32 具体实施方式 Pipette 31 filter 4

41 end cap 42 filter element 43 inlet port 44 outlet port 45 metering valve

6 Air throttle 61 Check valve 71 Diaphragm valve 72 First solenoid valve 73 Third electromagnetic wide 74 Through hole 75 Nozzle 76 Exhaust pipe 77 Vent pipe 79 Water heating unit 8 Inlet joint 81 Inlet pipe 82 Outlet pipe 83 Outlet joint 84 water circulation pipe 85 first flow path 86 heat exchanger 87 heat insulation sleeve 88 compressed air unit 9 gas source 91 second electromagnetic valve 92 pressure reducing valve 93 second temperature sensor 94 coarse filter device 32

 The technical solutions in the preferred embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

 As shown in FIG. 1 and FIG. 2, the integrated SCR reducing agent storage device of the present invention comprises a metering injection unit 1 and a liquid storage tank 2, and the metering injection unit 1 is integrated with the liquid storage tank 2 through a transition plate 3, the metering The spray unit includes a cover 11, a pump body 12, a diaphragm pump 13, a filter 4, a metering valve 5, a mixing chamber 6, a first pressure sensor 14, a second pressure sensor 15, a liquid flow conduit 16 disposed on the pump body, and Control unit 17.

As shown in FIG. 3, the cover 11 is fastened to the pump body 12, and forms a closed space with the pump body 12. The diaphragm pump 13, the metering valve 5, the mixing chamber 6, the first pressure sensor 14, and the second The pressure sensors 15 are disposed in the closed space formed by the cover body 1.1 and the pump body 12, and the filtering The device 4 is placed on the pump body 12 outside the cover body 11 for cleaning and maintenance; the diaphragm pump 13 is used for sucking the reducing agent from the liquid storage tank 2 into the liquid flow pipe 16 of the pump body, thereby Provides a power source for the delivery of the reducing agent.

 The filter 4 is fixedly mounted on the pump body 12 for filtering and suppressing pressure fluctuations, and includes a filter chamber housing 41, an end cover 42 and a filter housing. The filter element 43 is integrally formed on the pump body 12, and the end cover 42 is sealingly disposed at one end of the filter chamber housing 41. The filter chamber housing 41 is integrally formed on the pump body 12. A liquid inlet port 44 and a liquid outlet port 45 are provided, and the liquid inlet port 45 communicates with the liquid inlet port of the metering valve 5 through a liquid flow conduit 16 provided in the pump body. As shown in FIG. 4, the liquid inlet 44 of the filter 4 is disposed in a direction tangential to the inner wall of the filter housing 41, and the inlet port is tangentially disposed to avoid the inlet and the inlet. Due to the vertical setting, the filter chamber casing 41 causes the reductant injection pressure to directly impact the filter element to cause damage. At the same time, after the reducing agent biases the mandrel direction into the liquid storage chamber, the adherent flow forms a buffer to prevent vertical entry disturbance. The liquid causes a significant fluctuation in pressure and acts as a regulator.

 Referring to Figures 5 and 7, the metering valve 5 is a high-precision urea-specific metering valve for metering injection of a reducing agent in this embodiment. One end of the metering valve 5 is connected to the filter 4 through the through hole 75 and the liquid flow pipe 16 in the pump body, and the other end is connected to the mixing chamber 6, which is connected in series downstream of the metering valve 5, mainly serving as gas. The mixed atomization function of the liquid to form a uniform suspension to optimize the purification effect.

 In this embodiment, the injection hole portion of the metering valve 5 extends into the mixing chamber 6. The inner wall of the mixing chamber 6 is provided with an air orifice 61, and the other end of the air orifice 61 is connected to the air source. The air orifice 61 is tangential to the inner wall of the mixing chamber 6, which provides an inlet for the compressed gas source for the mixing of the gas and the liquid in the mixing chamber 6, and the high-speed airflow during the injection of the reducing agent by the metering valve 5. It enters the mixing chamber 6 tangentially through the air orifice 61.

According to the cyclone principle, when the tangential airflow enters the mixing chamber 6, an external swirling airflow and an internal swirling airflow are formed in the cavity, and the external swirling airflow is attached to the cavity wall for rotation, and is blown away from the liquid outlet joint. That is, blowing in the direction of the metering valve 5, when the top of the mixing chamber 6 is reached, an internal swirling airflow is formed, which is reversed from the outward flow, and at the same time, when the airflow is collected at the orifice of the metering valve 5, the injection pressure at the metering valve Under the action, the injected reducing agent is fully stirred by the internal swirling airflow, and is blown downward, and is ejected through the liquid outlet joint, and the urea can be dissolved in the mixing chamber 6 due to the stirring action. The liquid forms a uniform suspension, which reduces the risk of crystallization and facilitates the formation of a uniform spray at the atomizing nozzle downstream of the tapping joint to enhance the catalytic reduction reaction.

 The mixing chamber 6 is separated from the end of the metering valve 5 through a liquid line pipe 16 in the pump body to communicate with the liquid outlet joint 18 on the side wall of the pump body. The liquid outlet joint 18 is connected to the exhaust pipe 77 through the injection line and the nozzle 76. Pick up. Preferably, the position of the liquid outlet joint 18 is lower than the position of the metering valve 5, and the axis of the mixing chamber 6 forms an acute angle with the horizontal direction, that is, the mixing chamber 6 is inclined, and the mixing chamber 6 is It is better to form a 20° angle with the horizontal direction. Thus, even after the end of the spraying operation, even if there is residual reducing agent in the mixing chamber, the reducing agent will flow downward (ie, in the direction of the liquid outlet) due to gravity, and will not The backflow blocks the orifice of the metering valve.

 As shown in FIG. 7 and FIG. 8 , the liquid flow pipe 16 is composed of a plurality of sections of pipes which are disposed in a space disposed inside the pump body 12 and between the lower surface 121 of the pump body and the transition plate 3 , the diaphragm pump 13 , The filter 4 and the metering valve 5 are sequentially connected through a liquid flow pipe 16 in the pump body, and the liquid flow pipe 16 end is connected to a pipette 31 extending downward from the lower side of the transition plate 3, and then sequentially connected to the pump body. The diaphragm pump 13 and the check valve 71 on the 12 are divided into two flow passages, and one passage is connected to the liquid inlet 44 of the filter 4 through the through hole 75 and the annular groove 161 penetrating the pump body in the figure, and the injection is required. The reducing agent is sent into the filter 4 for filtration, and then sent to the metering valve 5; the other path forms a liquid returning pipe which is connected to the diaphragm valve 72 and the reservoir 2, as shown in FIG. The bottom of the liquid pipe 31 is connected to a coarse filtering device 32 to prevent impurities in the reducing agent from entering the injection system to cause clogging.

 2, 3, 7, and 9, the integrated SCR reducing agent storage device of the present invention further includes a water heating unit 8, which uses a heated engine cooling water cycle, which can be used in a cold season. The metering spray unit and the reducing agent in the reservoir are heated, and at the same time, the heated engine cooling water heats the pump body 12 by circulating in the water circulation duct.

 The water heating unit 8 includes a water inlet joint 81, an inlet pipe 82, an outlet pipe 83, a water outlet joint 84, and a plurality of water circulation pipes 85 including a first flow passage 851 and a second disposed in the pump body 12. a flow passage 852, and a third flow passage 853 formed between the lower surface 121 of the pump body 12 and the transition plate 3, the first flow passage 851 and the second flow passage 852 respectively and the water joint 81 provided on the side wall of the pump body and The outlet joint 84 is connected.

The inlet pipe 82 and the outlet pipe 83 are formed to extend downward from the lower side of the transition plate 3, and the upper ends thereof are respectively connected to the third circulation 853 of the water circulation pipe 85, and the bottom portions are connected by a heat exchanger 87. The water inlet joint 81, the water inlet pipe 82, the water outlet pipe 83, and the water outlet joint 84 are sequentially connected through the water circulation pipe 85 to form a good heating of the reducing agent in the pump body 12 and the liquid storage tank 2.

 Preferably, a heat exchanger 87 having a spiral structure for increasing the heating area is formed at the bottom of the liquid storage tank 82 at the junction of the inlet pipe 82 and the outlet pipe 83, and the heat insulating sleeve 88 is wrapped on the outer surface of the upper portion of the inlet pipe 82, The heat insulating sleeve 88 is arranged such that the heated cooling water avoids excessive heat loss when flowing through the upper portion of the water inlet pipe, but first melts the freezing of the bottom of the urea tank to facilitate suction.

 More preferably, the metered injection device of the present invention further includes a vent tube 79, the snorkel 79, the pipette 31 and the inlet pipe 82 are both enclosed within the insulating jacket 88.

 Referring to FIG. 3, a first electromagnetic valve 73 is further disposed on the pipeline of the water inlet pipe 82 in the water heating unit 8, the first electromagnetic wide 73 is electrically connected to the control unit 17, and the control unit 17 controls the first electromagnetic valve. 73 to control the heated cooling water to circulate and heat the ice.

 The control unit 17 is electrically connected to the diaphragm pump 13, the metering valve 5, and the first pressure sensor 14 and the second pressure sensor 15 installed at both ends of the metering valve 5 and the mixing chamber 6, wherein the first pressure sensor 14 is disposed At the upstream end of the metering valve 5, a second pressure sensor 15 is disposed at a downstream end of the metering valve 5, and the first pressure sensor 14 and the second pressure sensor 15 receive a commanded injection amount and a metering valve according to the control unit. The pressure difference at the end, and calculate the duty cycle of the opening pulse of the metering valve 5, to achieve the purpose of accurate metering.

 The metering injection device in this embodiment further includes a compressed air unit 9, which includes a gas source 91, a second electromagnetic valve 92, and a pressure reducing valve 93 connected in series, and the second electromagnetic valve 92 is electrically connected. The control unit 17 is further provided with an air filter downstream of the air source 91. The compressed air unit can provide air pressure for opening or closing the diaphragm valve 71, and can provide compressed air for atomization of the reducing agent in the mixing chamber 6. .

 3 and 9, the metering injection device of the present invention further includes an inductive component 19, the inductive component is composed of a displacement sensor and a first temperature sensor, and the inductive component and the water heating unit are integrated in the Below the metering spray unit, the sensing assembly is electrically coupled to a control unit within the metering spray unit, the sensing assembly providing sensing information of the liquid level and temperature within the reservoir. More preferably, a second temperature sensor 94 for measuring the problem of reducing agent in the pump body is further disposed in the pump body 12.

When the control unit receives the engine ignition signal, the control unit 17 controls the motor in the diaphragm pump 13 to start the emptying operation at a certain fixed speed, so that the reducing agent in the liquid flow conduit 16 passes back. The flow line is returned to the reservoir 2, and after about 30 seconds, the control unit 17 controls the second solenoid valve 72 to open the evacuation circuit, at which time the diaphragm pump 13 continues to operate, and the reducing agent flows through the flow conduit. After the filter 4 is sent to the upstream of the metering valve 5 by the pump body, the pressure continuously increases. When the pressure value P1 of the first pressure sensor 14 upstream of the metering valve 5 reaches the set value, the diaphragm pump motor stops, and the control is stopped. The unit receives the injection request and controls the metering valve 5 to start metering injection. The second pressure sensor 15 is used to collect the pressure value P2 downstream of the metering valve to calculate the pressure difference and adjust the metering valve to open the pulse width.

 After the control unit 17 controls the compressed air unit to close the liquid returning membrane, before the injection, the pressure value (P1) of the first pressure sensor 14 is small, at which time the control unit 17 controls the motor in the diaphragm pump to have a preset speed. After running, after about 5s, the pressure P1 in the filter chamber reaches the injection pressure value; after starting the injection, P1 will fall, and the falling speed is related to the injection amount. In order to maintain P1 stability, the motor starts to work, and the filter chamber is supplemented with reducing agent to maintain the P1 value. Stabilization, in this process, the motor speed is closed-loop controlled according to the injection quantity and the current P1 value, achieving the purpose of accurate measurement.

 When the temperature is low and heating is required, when the control unit 17 receives the low temperature signal of the temperature sensor in the inductive sensor, the control unit controls the second solenoid valve 92 to drive the water heating unit 8, and the heated engine cooling water sequentially flows through the water. The joint 81, the inlet pipe 82, the outlet pipe 83, and the water outlet joint 84 both achieve heating of the metering injection unit and heating of the reducing agent in the reservoir 2.

 Figure 10 is a system control diagram of the second embodiment of the present invention. Both the embodiment and the first embodiment belong to the air injection system, and the difference is that the nozzle 76 downstream of the metering injection unit 1 is connected to the air compression unit 9 to provide a second time. Atomization effect.

 11 is a control diagram of the system of the third embodiment of the present invention, which belongs to the airless injection system. The difference between this embodiment and the first embodiment is that the embodiment does not require the use of a compressed air unit, and the metering valve 5 directly injects the reducing agent into the exhaust pipe 77. And the return line is directly connected to the control unit 17 by the third electromagnetic width 74, and the control unit directly controls the third electromagnetic valve 74 to open or close to control the backflow, and complete the emptying operation.

 The technical content and the technical features of the present invention have been disclosed as above, but those skilled in the art can still make various substitutions and modifications without departing from the spirit and scope of the present invention based on the teachings and disclosures of the present invention. Therefore, the scope of protection of the present invention should not be limited to The disclosure of the embodiments is intended to cover various alternatives and modifications of the inventions

Claims

Claim An integrated SCR reductant storage device, characterized in that: the integrated SCR reductant storage device comprises a liquid storage tank and a metering injection unit, the storage tank is for storing a reducing agent, the metering injection unit and the The storage tank is integrated.  2. The integrated SCR reductant storage device according to claim 1, wherein: the integrated SCR reductant storage device further comprises a transition plate, and the metering injection unit is integrated with the liquid storage tank through a transition plate One.  3. The integrated SCR reductant storage device of claim 1 wherein: said integrated SCR reductant storage device comprises a water heating unit for heating said reservoir and metering spray unit.  4. The integrated SCR reductant storage device according to claim 1, wherein: the metering injection unit further comprises a cover body, a pump body, a diaphragm pump, a filter and a metering valve, and the cover body is fastened. An enclosed space is formed between the cover body and the pump body on the pump body, and at least the diaphragm pump is disposed in the closed space.  5. The integrated SCR reductant storage device according to claim 4, wherein: the integrated SCR reductant storage device further comprises a transition plate, the metering injection unit being integrated with the liquid storage tank through a transition plate One.  6. The integrated SCR reductant storage device according to claim 5, wherein: the metering injection unit comprises a water heating unit, the water heating unit extending downward from the transition plate to the liquid storage tank Inside, for heating the liquid storage tank and the metering injection unit.  7. The integrated SCR reductant storage device according to claim 6, wherein: the water heating unit comprises an inlet water inlet pipe, an outlet water pipe, and a water circulation pipe disposed in the metering injection unit, The inlet and outlet pipes extend into the reservoir. 8. The integrated SCR reductant storage device according to claim 7, wherein: the water heating unit further comprises a water inlet joint and a water outlet joint, and the water inlet joint and the water outlet joint are disposed on the pump body. The water inlet joint, the inlet pipe, the outlet pipe, the water circulation pipe and the outlet joint are connected. 9. The integrated SCR reductant storage device according to claim 7, wherein: the integrated SCR reductant storage device further comprises an inductive component disposed in the reservoir, the inductive component comprising a liquid The position sensor and the first temperature sensor.  10. The integrated SCR reductant storage device according to any one of claims 7-9, wherein: the water inlet pipe is further provided with a heat insulating sleeve.  11. The integrated SCR reductant storage device according to claim 4, wherein: a plurality of liquid flow conduits through which the reducing agent flows are formed in the pump body.  12. The integrated SCR reductant storage device according to claim 4, wherein: the metering injection unit further comprises a first pressure sensor and a second pressure sensor disposed at both ends of the metering valve.  13. The integrated SCR reductant storage device according to claim 4, wherein: the metering injection unit further comprises a control unit, the control unit electrically connecting the diaphragm pump and the metering valve to control the Spraying of the reducing agent.  14. The integrated SCR reductant storage device of claim 4, wherein: the integrated SCR reductant storage device further comprises a second temperature sensor disposed within the pump body.