A liquid reducing agent metering and injection device heated by an electrically driven pump coil

Abstract

The liquid reducing agent metering injection device provided by the present invention is heated by an electric driven pump coil. The heat generated by energizing the coil of the liquid reducing agent electric driven pump motor or electromagnet with conveying and / or withdrawing functions in the metering injection device is used to directly or indirectly heat and insulate or thaw antifreeze equipment such as a filtering energy storage device and its antifreeze pipeline. No special heating, thawing and insulation device is required, which greatly reduces the manufacturing and operating costs of the metering injection device.

Description

Technical Field

[0001] The invention belongs to the field of diesel engine exhaust aftertreatment, and relates to a liquid reducing agent metering injection device heated by an electric drive pump coil, and in particular to a urea aqueous solution metering injection device heated by an electric drive pump coil. Background Art

[0002] The metering injection device of liquid reducing agent (such as urea aqueous solution) is an important device in the selective catalytic reduction system (Selective Catalytic Reduction, SCR) of diesel engines. Its working principle is as follows: the delivery pump in the metering injection device sucks the urea aqueous solution from the urea storage tank, forms a urea aqueous solution with a stable pressure through the pressure stabilizing unit, and then injects the urea aqueous solution into the catalytic muffler in a quantitative manner in a fine mist through the dosing module. In this way, the fine mist urea aqueous solution first undergoes hydrolysis and pyrolysis reactions at high temperature to generate ammonia, and then the ammonia undergoes oxidation-reduction reactions with nitrogen oxides in the exhaust gas discharged by the diesel engine in the catalytic muffler to regenerate nitrogen and water, thereby achieving the purpose of reducing the nitrogen oxide emissions of the diesel engine.

[0003] like Figure 1 , which is a urea aqueous solution metering injection device in the prior art, and is composed of a urea aqueous solution storage tank 18, a liquid suction pipe A2, a pre-filter 3, a liquid suction pipe B4, a two-position four-way reversing valve 5, a liquid suction pipe C6, a delivery pump 7 (with urea aqueous solution supply and back-drawing functions), a main injection pipe A8, a two-position four-way reversing valve 5, a main injection pipe B9, a filtering energy storage device 1, an injection pipe 10, a dosing module 11, a liquid return pipe A12, a pressure sensor 13 (whose function is to detect the fluctuation of the injection pressure and transmit the fluctuation value to the controller, and the controller adjusts the speed or frequency of the delivery pump to stabilize the pressure fluctuation within a certain range), a pressure valve 14, a liquid return pipe B15, a throttle valve 16, a liquid return pipe C17, a back-drawing pipe A20, a back-drawing pipe B19, a back-drawing pipe C22 and a back-drawing pipe D21.

[0004] Here’s how it works:

[0005] Pressure building process: when the metering injection device builds pressure, the delivery pump 7 and the two-position four-way reversing valve 5 are opened, and the urea solution in the urea aqueous solution storage tank 18 enters the filtering energy storage device 1 through the suction pipe A2, the pre-filter 3, the suction pipe B4, the two-position four-way reversing valve 5, the suction pipe C6, the delivery pump 7, the main injection pipe A8, the two-position four-way reversing valve 5, and the main injection pipe B9; when the urea aqueous solution pressure in the return pipe A12 reaches 9 bar, the pressure valve 14 opens, and the excess urea aqueous solution in the filtering energy storage device 1 flows back to the urea aqueous solution storage tank 18 through the return pipe A12, the pressure valve 14, the return pipe B15, the throttle valve 16, and the return pipe C17. In this way, the delivery pump 7 runs continuously to keep the urea aqueous solution pressure in the filtering energy storage device 1 unchanged.

[0006] Metered injection process: when the controller receives the injection signal, the dosing module 11 is electronically opened, and the urea aqueous solution in the filtering energy storage device 1 is quantitatively injected from the nozzle in the dosing module 11 through the injection pipe 10. At the same time, the delivery pump 7 continuously runs to replenish the urea aqueous solution in the filtering energy storage device 1 to keep its pressure stable. When the pressure of the urea aqueous solution in the return pipe A12 reaches 9 bar, the pressure valve 14 is hydraulically opened to allow the excess urea aqueous solution in the filtering energy storage device 1 to overflow back into the urea aqueous solution storage tank 18.

[0007] Evacuation process: firstly, power on the two-position four-way reversing valve 5, then electronically control to open the nozzle in the metering module 11, and then electronically control to start the delivery pump 7. In this way, when the metering injection device is stopped, the urea aqueous solution remaining in the metering injection device is sequentially drawn from the metering module 11 in the injection branch, the injection pipe 10, the filtering energy storage device 1, the withdrawal pipe A20 in the withdrawal branch, the two-position four-way reversing valve 5, the withdrawal pipe B19, the suction pipe C6 in the supply branch, and then sucked into the delivery pump 7; then sequentially from the main injection pipe 8 in the supply branch, the withdrawal pipe C22 in the withdrawal branch, the two-position four-way reversing valve 5, the withdrawal pipe D21, and then through the suction pipe B4 in the supply branch, the filter 3, the suction pipe A2, and finally flows back to the storage tank 18.

[0008] The above-mentioned metering injection device not only has a complex structure of the two-position four-way reversing valve 5, but also has a complex backflow branch pipeline connected thereto, which often leaves some urea aqueous solution in the reversing valve and the backflow branch pipeline, causing them to be frozen and cracked in winter and unable to be used; even if the metering injection device is not frozen and cracked in winter when it is stopped, in order to ensure that the metering injection device can be started and operated normally in a low temperature environment, not only the reversing valve and its connecting pipelines must be heated, thawed and insulated, but also the remaining equipment and pipelines except the urea aqueous solution storage tank 18 must be heated, thawed and insulated. Figure 2 and 3, which is an electric heating device for the above-mentioned metering injection device in the prior art, and the heating wire 34 is injection-molded into the plastic frame 35 (the plastic frame material is nylon or PA66). The shape and structure of the electric heating device must be attached to the outer surface of the equipment and pipeline in the above-mentioned metering injection device except the urea aqueous solution storage tank 18. Its structure is quite complicated and has high requirements on its manufacturing process. Summary of the invention

[0009] In order to solve the above problems, the purpose of the present invention is to provide (basic solution) a liquid reducing agent metering injection device heated by an electric drive pump coil, mainly including an electric drive pump, an antifreeze device and its antifreeze connecting pipeline, and a controller, the controller is used to power and control the metering injection device; add power to the coil of the electric drive pump motor or electromagnet of the metering injection device, heat and thaw or heat and keep warm at least one antifreeze device or at least one section of the antifreeze connecting pipeline in the metering injection device, and ensure that the electric drive pump motor or electromagnet can work normally after heating and thawing or heating and keeping warm. Further, the power supply is a PWM pulse width modulation current.

[0010] A preferred solution of the basic solution: the metering injection device further includes a temperature sensor connected to the controller for monitoring the temperature of the liquid reducing agent. When the metering injection device is powered on or in operation, the temperature sensor detects that the liquid reducing agent in the antifreeze device or the antifreeze connecting pipeline is at or below the freezing temperature, and the controller applies power to the coil of the electric drive pump motor or the electromagnet to heat and thaw or heat and keep warm at least one antifreeze device or at least one section of the antifreeze connecting pipeline in the metering injection device. Furthermore, the power supply is a PWM pulse width modulated current.

[0011] The basic scheme or its preferred scheme: the antifreeze device is the liquid reducing agent pump body, liquid reducing agent valve body, liquid reducing agent filter body (equipment with filtering function, such as pre-filter, filtering energy storage device, etc.) in the metering injection device. Further, the electric drive pump is a liquid reducing agent pump with supply and / or withdrawal function. Furthermore, the liquid reducing agent is urea aqueous solution or AdBlue or Add Blue.

[0012] A further preferred solution of the basic solution or its further preferred solution: it also includes a heat conductor arranged between the motor or electromagnet body of the electric drive pump and the antifreeze device or the antifreeze connecting pipe, which is used to transfer the heat of the electric drive pump coil in the device to the antifreeze device or the antifreeze connecting pipe.

[0013] A further preferred embodiment of the further preferred embodiment 1: the heat conductive element comprises a heat conductive block body and its upper surface and / or lower surface has a concave arc, and the concave arc on its surface is used to embed at least one of the outer shell of the electric drive pump coil, the outer shell of the antifreeze device and the antifreeze connecting pipeline.

[0014] A further further preferred solution of the further preferred solution 2: the heat conductor comprises a heat conductor body and a cavity thereof, and at least one is arranged on the heat conductor body for installing the motor or electromagnet body of the electric drive pump, or the liquid reductant pump body of the electric drive pump.

[0015] A preferred embodiment of the preferred embodiment 1 or the preferred embodiment 2: the heat-conducting element body is made of high-temperature resistant flame-retardant engineering plastic by injection molding, or is made of aluminum alloy by pressure casting or extrusion stretching. Further, the high-temperature resistant flame-retardant engineering plastic is nylon or polyethylene terephthalate (PET) or PA66.

[0016] A preferred solution of the preferred solution 1 or the preferred solution of the preferred solution 2: the electrically driven pump is a liquid reducing agent pump with supply and / or withdrawal functions. Further, the power supply is a PWM pulse width modulation current. Further, the antifreeze device is a liquid reducing agent pump body, a liquid reducing agent valve body, and a liquid reducing agent filter body in the metering injection device. Further, the liquid reducing agent is a urea aqueous solution or AdBlue or Add Blue.

[0017] The liquid reducing agent metering injection device provided by the present invention, which is heated by an electric drive pump coil, utilizes the heat generated by the coil of the liquid reducing agent electric drive pump motor or electromagnet with conveying and / or withdrawing functions in the metering injection device to directly or indirectly heat and insulate or heat and thaw antifreeze equipment such as a filtering energy storage device and other antifreeze pipelines, without the need to set up a special heating, thawing and insulation device, thereby greatly reducing the manufacturing and operating costs of the liquid reducing agent metering injection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a urea metering injection device in the prior art.

[0019] Figure 2 for Figure 1 Schematic plan view of the heating device structure.

[0020] Figure 3 for Figure 2 A schematic three-dimensional diagram of the disassembled structure of the heating skeleton and its heating wires in the heating device.

[0021] Figure 4 for Figure 1 Schematic diagram of the longitudinal cross-section structure of the filtering energy storage device.

[0022] Figure 5 for Figure 4 Schematic diagram of the AA cross-sectional structure.

[0023] Figure 6 A kind of Figure 1 Schematic diagram of the longitudinal section structure of the central delivery pump electromagnet body directly heating the filter energy storage device.

[0024] Figure 7 for Figure 6 Schematic diagram of the AA cross-sectional structure.

[0025] Figure 8 A kind of Figure 1 Schematic diagram of the longitudinal section structure of the middle delivery pump electromagnet body heating the filter energy storage device through the heat conductive block.

[0026] Fig. 9 for Figure 8 Schematic diagram of the AA cross-sectional structure.

[0027] Fig.10 A kind of Figure 1 Schematic diagram of the cross-sectional structure of the heat-conducting component through which the electromagnet body of the middle delivery pump heats the filtering energy storage device. DETAILED DESCRIPTION

[0028] The following is a detailed description of the urea metering injection device provided by the present invention based on the urea metering injection device described in the background technology part and in combination with the accompanying drawings and specific embodiments of the present invention.

[0029] Figure 1 The filtration energy storage device in the prior art urea metering injection device is as shown in Figure 4 and 5 The present invention is described by taking a schematic diagram of the structure of a filtering energy storage device as an example. The device is mainly composed of a paper filter layer 01, a hollow rubber rod 02 and a cap-shaped shell 03. The paper filter layer 01 and the hollow rubber rod 02 are sequentially embedded from an open end of the cap-shaped shell 03 and fixed (through a thread) on the outer side of the end through an end cap 04 with a center hole; a urea aqueous solution inlet 05 is arranged at the other end of the shell 03, and the urea aqueous solution passes through the paper filter layer 01 and directly flows to the hollow rubber rod 02, and the urea aqueous solution inlet 5 is connected to the main injection pipe B9; a urea aqueous solution injection outlet 07 is arranged in the middle of the side wall of the shell 03, which is connected to the injection pipe 10; a urea aqueous solution return liquid outlet 06 is arranged at the bottom of the side wall of the shell 03 (arranged at the bottom of the side wall to facilitate the evacuation of the urea aqueous solution), which is connected to the return liquid pipe A12.

[0030] Example 1

[0031] like Figure 6 and7 For a Figure 1 The schematic diagram of the structure in which the delivery pump in the urea metering injection device drives the electromagnet body to directly heat the filter energy storage device, wherein the filter energy storage device and Figure 4 and 5 The difference between the filter energy storage device shown is that the delivery pump driving electromagnet housing body is directly set at one end of the urea aqueous solution inlet of the filter energy storage device, the urea aqueous solution inlet 05 is changed to the side wall of the filter energy storage device housing 03, and the path of the urea aqueous solution flowing into the filter energy storage device is changed from direct flow into the side wall of the filter energy storage device housing 03 and then turn left to flow in. The electromagnet mainly consists of an electromagnet housing 701, a coil 703 and an electric iron core 702. The electromagnet housing 701 is connected to one end of the filter energy storage device housing 03 by screws 36.

[0032] Working principle:

[0033] The metered injection device includes a controller (not shown in the figure) for controlling and supplying power to the equipment in the device and a temperature sensor (not shown in the figure) connected to the controller for monitoring the lowest temperature point of the liquid reducing agent in the device. When the metered injection device does not perform metered injection, and the temperature sensor detects that the temperature of the urea aqueous solution in the filtering energy storage device is at or below the freezing point, the controller adds a PWM pulse width modulation current to the coil of the delivery pump driving electromagnet, and directly thaws or heats the filtering energy storage device through heat transfer from the electromagnet housing 701; when the temperature sensor detects that the temperature of the urea aqueous solution in the filtering energy storage device is greater than the freezing point, the controller stops adding the PWM pulse width modulation current to the coil of the delivery pump driving electromagnet.

[0034] In order to ensure that the coil of the delivery pump driving electromagnet is not burned out due to the heating by the PWM pulse width modulation current (i.e., to ensure that the electric drive pump motor or electromagnet can work normally after the above-mentioned heating thawing or heating insulation), a temperature sensor at the lowest temperature point of the liquid reducing agent or a temperature sensor can be set on the shell of the delivery pump driving electromagnet to monitor the temperature during its heating process. Once it is overheated, the loading of the PWM pulse width modulation current is stopped or the size of the PWM pulse width modulation current is reduced; the coil of the delivery pump driving electromagnet can also be designed by loading the coil of the delivery pump driving electromagnet with a certain specific PWM pulse width modulation current according to actual needs, so as to determine the heating time of the current, so that the limit heating time is greater than the actual heating time; this ensures that the coil of the delivery pump driving electromagnet will not be burned out during the heating process by the PWM pulse width modulation current.

[0035] When the metering injection device stops working, that is, the system stops injecting, in order to prevent the urea aqueous solution in the filtering energy storage device from freezing and affecting the normal operation of the metering injection device, the controller can also add PWM pulse width modulation current to the coil of the electromagnet driving the delivery pump in the metering injection device, and directly heat and keep the filtering energy storage device warm through heat transfer from the electromagnet housing 701; when the metering injection device starts working again, that is, the system injects, the controller stops adding PWM pulse width modulation current to the coil of the electromagnet driving the delivery pump in the metering injection device.

[0036] Since the metering injection device uses the coil of the delivery pump driving electromagnet in the device to heat and defrost or heat and keep warm the filtering energy storage device, the complicated electric heating injection molding dedicated device in the prior art is no longer required, which greatly reduces the overall cost and operating cost of the metering injection device.

[0037] Example 2

[0038] like Figure 8 and 9 For a Figure 1 The schematic diagram of the structure of the delivery pump driving electromagnet body in the urea metering injection device heating the filter energy storage device through the heat conduction block (i.e., heat conduction member). The difference between this embodiment and embodiment 1 is that the delivery pump driving electromagnet is arranged outside the side wall of the filter energy storage device, and a heat conduction block 30 is fixedly arranged between the electromagnet and the filter energy storage device; during heating, the filter energy storage device is indirectly heated by heat transfer through the electromagnet housing 701 and then by the heat conduction block 30; the urea aqueous solution inlet 05 of the filter energy storage device does not need to be arranged on the side wall of its housing 03 as in embodiment 1; the rest of the structure and working principle are basically the same as in embodiment 1.

[0039] Example 3

[0040] like Fig.10 , which is a kind of Figure 1 The schematic diagram of the cross-sectional structure of the heat-conducting member in which the electromagnet body of the delivery pump heats the filtering energy storage device through the heat-conducting member, the heat-conducting member 30 is composed of a heat-conducting member body 301 and two adjacent cavities A302 and B303 arranged thereon, which are formed by extrusion, stretching or injection molding of engineering plastics (nylon or PA66), or by pressure casting of aluminum alloy; the delivery pump 7 as a whole or the pump body or its coil housing is installed in the cavity A302, and the filtering energy storage device 1 is installed in the cavity C303; in this way, when the filtering energy storage device 1 in the metering injection device is heated and thawed or heated and kept warm, the heat generated by the electromagnet coil of the delivery pump 7 is used to transfer heat to the filtering energy storage device 1 through the heat-conducting member body 301 for heating and thawing or heating and keeping warm (for heating and thawing or heating and keeping warm, refer to the working principle of heating and thawing or heating and keeping warm in Example 1).

[0041] The above embodiments are only specific Figure 1 The idea of ​​the present invention is explained by energizing the electromagnet of the delivery pump 7 in the urea metering injection device to heat and keep warm or heat and thaw a specific filtering energy storage device 1.

[0042] To prevent Figure 1 The remaining antifreeze devices (such as the filter energy storage device 1, the pre-filter 3, the pressure sensor 13, the pressure valve 14, the throttle valve 16 and the two-position four-way reversing valve 5, etc.) and the antifreeze connecting pipeline in the urea metering injection device shown in the figure, except for the storage box and the dosing module, are frozen and cracked due to the residual urea solution. At least one of the above antifreeze devices and / or at least one section of the antifreeze connecting pipeline can also be heated and thawed or heated and kept warm by adopting a heating structure similar to that in the above embodiments 1-3.

[0043] In addition, the filtering energy storage device of the present invention can also be a hollow rubber energy storage filtering device of other structures, and is not limited by the specific structure in the above embodiment; the urea metering injection device of the present invention is also not limited to Figure 1 The limitations of the urea metering injection device shown in the figure, such as the urea metering injection device delivery pump 7 in the above embodiment has the supply and withdrawal functions as one, while other urea metering injection devices have a pump for the supply function and a pump for the withdrawal function, as long as the pump used is an electrically driven pump (such as a motor or electromagnet driven).

[0044] The urea aqueous solution in the present invention may also be a liquid reducing agent such as AdBlue or AdBlue.

[0045] As long as the electric drive pump motor or electromagnet coil can heat and thaw or heat and keep warm the above-mentioned antifreeze equipment or antifreeze connecting pipeline, the heating structure between them is not limited by the specific structure in the above-mentioned embodiments. Therefore, the present invention is not limited by the above-mentioned embodiments. Without departing from the spirit and scope of the present invention, the present invention is also capable of various changes and modifications, which all fall within the scope of the present invention to be protected; the scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A liquid reducing agent metering injection device heated by an electrically driven pump coil, characterized in that: The invention comprises an electric drive pump, an antifreeze device and an antifreeze connecting pipeline thereof, and a controller, wherein the controller is used to supply power to and control the metering injection device; a power source is applied to the coil of the motor or electromagnet of the electric drive pump of the metering injection device, and at least one antifreeze device or / and at least one section of the antifreeze connecting pipeline in the metering injection device is heated and thawed or heated and kept warm, and after heating and thawing or heating and keeping warm, the electric drive pump is ensured to work normally, The motor or electromagnet of the electric drive pump is directly connected to the antifreeze device or the antifreeze connecting pipeline or connected through a heat conductor to transfer the heat of the coil of the electric drive pump to the antifreeze device or the antifreeze connecting pipeline.

2. The liquid reducing agent metering injection device according to claim 1, characterized in that: The metering injection device also includes a temperature sensor connected to the controller for monitoring the temperature of the liquid reducing agent; when the metering injection device is powered on or during operation, when the temperature sensor detects that the liquid reducing agent in the antifreeze device or the antifreeze connecting pipeline is at or below the freezing temperature, the controller applies power to the coil of the motor or electromagnet of the electric drive pump to heat and thaw or heat and keep warm at least one antifreeze device and / or at least one section of the antifreeze connecting pipeline in the metering injection device.

3. The liquid reducing agent metering injection device according to claim 1 or 2, characterized in that: The power supply is a PWM pulse width modulation current.

4. The liquid reducing agent metering injection device according to claim 3, characterized in that: The antifreeze equipment is the liquid reducing agent pump body, the liquid reducing agent valve body and the liquid reducing agent filter body in the metering injection device.

5. The liquid reducing agent metering injection device according to claim 4, characterized in that: The electric drive pump is a liquid reducing agent pump with supply and / or withdrawal functions.

6. The liquid reducing agent metering injection device according to claim 5, characterized in that: The liquid reducing agent is urea aqueous solution or AdBlue or AdBlue.

7. The liquid reducing agent metering injection device according to claim 1, characterized in that: The heat conductor includes a heat conductor body and an upper surface or / and a lower surface thereof with a concave arc, wherein the concave arc is used to embed at least one of the outer shell of the coil of the electric drive pump, the outer shell of the antifreeze device and the antifreeze connecting pipeline.

8. The liquid reducing agent metering injection device according to claim 1, characterized in that: The heat-conducting member comprises a heat-conducting member body and a cavity thereof. At least one cavity is arranged on the heat-conducting member body for mounting the motor or electromagnet body of the electric drive pump, or the liquid reducing agent pump body of the electric drive pump.

9. The liquid reducing agent metering injection device according to claim 7 or 8, characterized in that: The heat conducting element body is made of high temperature resistant flame retardant engineering plastics by injection molding, or made of aluminum alloy by pressure casting or extrusion stretching.

10. The liquid reducing agent metering injection device according to claim 9, characterized in that: The high temperature resistant flame retardant engineering plastic is nylon or polyethylene terephthalate or PA66.

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