Double-injection urea pump and SCR injection system

Abstract

The utility model discloses a double-injection urea pump and an injection system, and relates to the technical field of engine tail gas treatment. Comprising a pump body; the pump body is provided with a liquid suction cavity, a liquid inlet cavity and a liquid discharge cavity; a diaphragm is arranged in the liquid suction cavity; a first sealing structure is arranged between the liquid suction cavity and the liquid inlet cavity, and a second sealing structure is arranged between the liquid suction cavity and the liquid discharge cavity; the first sealing structure is configured to be opened so that urea can enter the liquid suction cavity through the liquid inlet cavity when the diaphragm deviates from the liquid suction cavity and negative pressure is formed in the diaphragm. The second sealing structure is configured to be opened when the diaphragm compresses the liquid suction cavity to form positive pressure in the liquid suction cavity, so that urea is discharged out of the liquid suction cavity through the liquid discharge cavity; only the diaphragm is arranged in the liquid suction cavity in the pump body, and structures such as a valve element and a valve plate are not arranged, so that the structure is simplified, the internal volume of the liquid suction cavity is increased, and the double-spray flow of urea is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of engine tail gas treatment, and specifically relates to a double-spray urea pump and an SCR injection system. Background Art

[0002] SCR (Selective Catalytic Reduction) technology is one of the main post-treatment technologies for eliminating nitrogen oxides in diesel engine exhaust. It controls the urea dosing unit according to sensor signals such as exhaust temperature, urea temperature, and urea pressure, and injects urea solution into the exhaust gas flow in a timely and quantitative manner according to demand, thereby reducing nitrogen oxides, the main harmful components in the exhaust, into nitrogen and water.

[0003] During the injection process, a urea pump is usually used to inject urea. A valve plate and a valve core are provided in the existing urea pump. The valve core pushes the valve plate to realize the movement of the diaphragm to absorb urea into the suction chamber and discharge urea from the suction chamber. The valve core and the valve plate occupy most of the space inside the pump body of the urea pump. The internal structure is complex, resulting in a small internal space of the suction chamber and a low negative pressure capacity of the suction chamber, which in turn leads to a low flow rate of urea and cannot meet the use requirements. Moreover, the existing urea pump also adopts a reflux structure, so the urea pump needs to work continuously. The reflux structure will cause part of the urea to return to the urea tank, resulting in a certain amount of urea flow wasted, which can only meet single-tube injection, but cannot meet double-tube injection, and cannot increase the use flow rate of urea. For example, the existing patent application number is CN202121020092.1, and the patent name is a urea pump and engine, which discloses that the pump cover, the pump body and the diaphragm form a pressure storage chamber for accommodating urea, and the valve core and the base are respectively arranged at both ends of the protective valve, and the pump cover is provided with an inlet valve, an outlet valve and a protective valve, and the protective valve includes a valve core, a valve body, a connecting rod, a suction structure and a base; the inlet valve, the outlet valve and the protective valve have complex structures and occupy more space in the pressure storage chamber, so that the liquid space in the pressure storage chamber is smaller, resulting in a lower liquid flow rate. Utility Model Content

[0004] The utility model provides a dual-spray urea pump and an SCR injection system to solve the problems in the prior art that the valve core and other structures inside the urea pump are complex, occupy more space, cause low negative pressure, thus cause low urea flow, and cannot realize dual spray.

[0005] The technical solution adopted by the utility model is:

[0006] The present application relates to a double-spray urea pump, comprising a pump body; the pump body has a liquid suction chamber, a liquid inlet chamber and a liquid discharge chamber; a diaphragm is arranged in the liquid suction chamber; a first sealing structure is arranged between the liquid suction chamber and the liquid inlet chamber, and a second sealing structure is arranged between the liquid suction chamber and the liquid discharge chamber;

[0007] The first sealing structure is configured such that when the diaphragm moves away from the liquid absorption chamber to form a negative pressure inside the chamber, the first sealing structure opens to allow urea to enter the liquid absorption chamber through the liquid inlet chamber; and the second sealing structure is configured such that when the diaphragm compresses the liquid absorption chamber to form a positive pressure inside the chamber, the second sealing structure opens to allow urea to be discharged from the liquid absorption chamber through the liquid discharge chamber.

[0008] A double-spray urea pump of the utility model also has the following additional technical features:

[0009] A first flow port is formed between the suction chamber and the liquid inlet chamber, and urea enters the suction chamber through the first flow port after entering the liquid inlet chamber; a second flow port is formed between the suction chamber and the liquid discharge chamber, and urea enters the liquid discharge chamber from the suction chamber through the second flow port.

[0010] The first sealing structure adopts a first one-way valve; the first one-way valve is connected from the liquid inlet chamber to the liquid suction chamber, and a first spring is connected between the first one-way valve and the liquid inlet chamber, so that after urea flows from the liquid inlet chamber to the liquid suction chamber, the first flow port is blocked under the elastic force of the first spring.

[0011] The first sealing structure adopts a first one-way valve, and the first one-way valve is connected from the liquid inlet chamber to the liquid suction chamber; a first spring is connected between the first one-way valve and the liquid inlet chamber, so that after urea flows from the liquid inlet chamber to the liquid suction chamber, the first flow port is blocked under the elastic force of the first spring.

[0012] The second sealing structure adopts a second one-way valve, and the second one-way valve is connected from the suction chamber to the discharge chamber; a second spring is connected between the second one-way valve and the suction chamber, so that after urea is discharged from the suction chamber to the discharge chamber, the second flow port is blocked under the elastic force of the second spring.

[0013] The urea pump also includes a pressure-stabilizing chamber structure connected to the drainage chamber; the pressure-stabilizing chamber structure includes a protective cover; a pressure-stabilizing chamber for pressure compensation of the drainage chamber is formed in the protective cover; a pressure compensating component is arranged in the pressure-stabilizing chamber, and the pressure compensating component is configured to be compressed by urea and generate a rebound force capable of promoting urea output.

[0014] The protective cover is provided with a water inlet and a water outlet respectively connected to the pressure stabilizing cavity; the water inlet is connected to the drainage cavity through a first flow pipe, and the water outlet is connected to the filtering device through a second flow pipe.

[0015] The drainage cavity is provided with a drainage port, and the water inlet is connected to the drainage port through a first flow pipe; the liquid inlet cavity is provided with a liquid inlet, and the liquid inlet is connected to the urea tank through a third flow pipe.

[0016] The third circulation pipe is also connected in series with a pressure sensor, and the pressure sensor is arranged on the downstream side of the filtering device; the end of the third circulation pipe provided with the pressure sensor is respectively connected to the first injection pipe and the second injection pipe, and urea is injected through the first injection pipe and the second injection pipe.

[0017] The present application also relates to an SCR injection system, comprising the above-mentioned dual-injection urea pump, and also comprising a first nozzle and a second nozzle; the first injection pipe is connected to the first nozzle, the second injection pipe is connected to the second nozzle, and urea is injected through the first nozzle and the second nozzle respectively.

[0018] Due to the adoption of the above technical solution, the beneficial effects achieved by the utility model are as follows:

[0019] 1. The present application relates to a dual-spray urea pump, comprising a pump body; the pump body has a liquid suction chamber, a liquid inlet chamber and a liquid discharge chamber; a diaphragm is arranged in the liquid suction chamber; a first sealing structure is arranged between the liquid suction chamber and the liquid inlet chamber, and a second sealing structure is arranged between the liquid suction chamber and the liquid discharge chamber; the first sealing structure is configured such that when the diaphragm deviates from the liquid suction chamber to form a negative pressure inside the liquid suction chamber, the first sealing structure opens to allow urea to enter the liquid suction chamber through the liquid inlet chamber; the second sealing structure is configured such that when the diaphragm compresses the liquid suction chamber to form a positive pressure inside the liquid suction chamber, the second sealing structure opens to allow urea to be discharged from the liquid suction chamber through the liquid discharge chamber. The liquid suction chamber inside the pump body is only provided with a diaphragm, without structures such as a valve core and a valve plate, which greatly simplifies the structure of the device, reduces the production process cost and technical difficulty, and increases the volume inside the liquid suction chamber, increases the negative pressure of the liquid suction chamber, and further increases the dual-spray flow rate of urea.

[0020] 2. As a preferred embodiment of the present utility model, the urea pump also includes a pressure-stabilizing chamber structure connected to the drainage chamber; the pressure-stabilizing chamber structure includes a protective cover; a pressure-stabilizing chamber for pressure compensation of the drainage chamber is formed in the protective cover; a pressure compensating component is arranged in the pressure-stabilizing chamber, and the pressure compensating component is configured to be compressed by urea and generate a rebound force capable of promoting urea output. The pressure-stabilizing chamber structure is used to achieve pressure compensation for the urea pump body, thereby making the pressure of the urea pump more stable; a traditional urea pump is provided with a reflux structure, because the urea pump can work all the time with the reflux structure to ensure pressure stability, and the present application can further achieve pressure stability by providing a pressure-stabilizing chamber structure, so there is no need to provide a reflux structure; and because there is no reflux structure, the urea pump does not need to work all the time, so the urea pump can stop working when there is no injection demand, and the pump body will work again when there is a sudden injection demand, but the sudden operation of the pump body will have a lag, and providing a pressure-stabilizing chamber structure can provide pressure compensation to offset the occurrence of this situation; in addition, because there is no reflux structure, when the motor connected to the same urea pump and the size of the diaphragm in the urea pump are the same, the urea flow rate can be further increased, and the injection supply demand of the double-tube urea can be achieved.

[0021] 3. As a preferred embodiment of the utility model, the first sealing structure adopts a first one-way valve; the first one-way valve is connected from the liquid inlet chamber to the liquid suction chamber, and a first spring is connected between the first one-way valve and the liquid inlet chamber, so that after urea flows from the liquid inlet chamber to the liquid suction chamber, the first flow port is blocked under the elastic force of the first spring. The first one-way valve ensures that urea can only flow toward the liquid suction chamber through the liquid inlet chamber. When negative pressure is formed in the liquid suction chamber, urea in the urea box flows from the liquid inlet chamber to the liquid suction chamber through the opened first one-way valve. When urea no longer needs to enter the liquid inlet chamber, the diaphragm stops the movement of compressing the liquid suction chamber inward, and the first one-way valve can be restored to the initial position under the action of the rebound force of the first spring, thereby realizing the storage of urea in the closed liquid suction chamber.

[0022] 4. As a preferred embodiment of the utility model, a throttle valve and a third one-way valve are further connected to the third flow pipe along the flow direction of urea in the third flow pipe, and the throttle valve and the third one-way valve are connected from the water outlet to the filter device. The third one-way valve allows urea to flow out of the pressure stabilizing chamber structure and then flow to the filter device, rather than flowing back into the pressure stabilizing chamber structure, so that the urea flow is more stable and smooth.

[0023] 5. As a preferred embodiment of the utility model, the third circulation pipe is also connected in series with a pressure sensor, and the pressure sensor is arranged on the downstream side of the filtering device; the end of the third circulation pipe provided with the pressure sensor is respectively connected to the first injection pipe and the second injection pipe, and urea is injected through the first injection pipe and the second injection pipe. By setting the pressure sensor to detect the specific flow value, timely adjustment is achieved to ensure flow and pressure stabilization. At the same time, by setting the first injection pipe and the second injection pipe, urea is stably injected from the first injection pipe and the second injection pipe, realizing double-tube injection and increasing the flow of urea. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0025] Figure 1 This is a working principle diagram of a double-spray urea pump in one embodiment of the utility model;

[0026] Figure 2 This is a diagram showing the internal structure of a pump body of a double-spray urea pump according to an embodiment of the utility model;

[0027] Figure 3 This is a working principle diagram of a double-spray urea pump for sucking and discharging liquid in one embodiment of the utility model;

[0028] Figure 4 It is a schematic diagram of a pressure stabilizing chamber structure of a double-spray urea pump in one embodiment of the utility model;

[0029] In the figure,

[0030] 1 pump body, 11 diaphragm, 12 first sealing structure, 13 second sealing structure;

[0031] 2 pressure stabilizing chamber structure, 21 protective cover, 22 pressure stabilizing chamber body, 23 pressure compensation component;

[0032] 3 throttle valve, 4 third one-way valve, 5 first nozzle, 6 pressure sensor, 7 filtering device, 8 second nozzle, 9 liquid suction chamber, 10 liquid inlet chamber, 14 liquid discharge chamber, 15 water inlet, 16 water outlet. DETAILED DESCRIPTION

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0034] In addition, in the description of the present invention, it should be understood that the terms "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present utility model, unless otherwise clearly specified and limited, the first feature "above" or "below" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "implementation method", "example", "one embodiment", "example" or "specific example" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples. In the prior art, for example, the patent application number is CN202121020092.1, and the patent name is a urea pump and engine, which discloses that the pump cover, the pump body 1 and the diaphragm 11 form a pressure storage chamber for accommodating urea, the valve core and the base are respectively arranged at the two ends of the protection valve, and the pump cover is provided with an inlet valve, an outlet valve and a protection valve, and the protection valve includes a valve core, a valve body, a connecting rod, a suction structure and a base; the inlet valve, the outlet valve and the protection valve have complex structures and occupy more space in the pressure storage chamber, so that the liquid space in the pressure storage chamber is small, resulting in a low flow rate of the liquid. Moreover, the existing urea pump also adopts a reflux structure, so that the urea pump needs to work continuously, and the reflux structure will cause part of the urea to return to the urea tank, resulting in a certain waste of urea flow, which can only meet the single-tube injection, but cannot meet the double-tube injection, and cannot increase the use flow rate of urea.

[0037] In order to more clearly illustrate the overall concept of the present invention, a detailed description is given below in the form of examples in conjunction with the accompanying drawings.

[0038] The present application relates to a double-spray urea pump, such as Figures 1 to 4 As shown, it includes a pump body 1; the pump body 1 has a suction chamber 9, a liquid inlet chamber 10 and a liquid discharge chamber 14; a diaphragm 11 is arranged in the suction chamber 9; a first sealing structure 12 is arranged between the suction chamber 9 and the liquid inlet chamber 10, and a second sealing structure 13 is arranged between the suction chamber 9 and the liquid discharge chamber 14; the first sealing structure 12 is configured so that when the diaphragm 11 deviates from the suction chamber 9 to form a negative pressure inside thereof, the first sealing structure 12 opens to allow urea to enter the suction chamber 9 through the liquid inlet chamber 10; the second sealing structure 13 is configured so that when the diaphragm 11 compresses the suction chamber 9 to form a positive pressure inside thereof, the second sealing structure 13 opens to allow urea to be discharged from the suction chamber 9 through the liquid discharge chamber 14.

[0039] like Figure 2 As shown, the pump body 1 is provided with a liquid suction chamber 9 for accumulating pressure of urea, and the diaphragm 11 is located on one side of the liquid suction chamber 9. Figure 3 As shown in the figure, the first row is the process of the pump body sucking liquid, and the second row is the process of the pump body discharging liquid. A liquid inlet chamber 10 connected to the urea tank is provided on one side of the liquid suction chamber 9, and a liquid discharge chamber 14 connected to the pressure-stabilizing chamber structure 2 described below is provided on the other side of the liquid suction chamber 9. When the pump body needs to absorb urea, the diaphragm 11 can expand outward, that is, move linearly away from the liquid suction chamber 9. At this time, the liquid suction chamber 9 forms a large negative pressure inside the liquid suction chamber 9 due to the increase in the internal space. When the liquid suction chamber 9 forms a negative pressure, the urea from the urea tank will flow into the liquid suction chamber 9. The flowing urea enters the liquid inlet chamber 10 and opens the first sealing structure 12 under the pressure of the flow rate. The first sealing structure 12 can only be conducted from the liquid inlet chamber 10 to the liquid suction chamber 9, so that urea will flow from the liquid inlet chamber 10 to the liquid suction chamber 9, so that the liquid suction chamber 9 is filled with urea; when the pump body needs to discharge liquid, when the diaphragm 11 compresses the liquid suction chamber 9 inwardly under the action of the driving mechanism, a positive pressure is formed inside the liquid suction chamber 9, and urea no longer flows into the liquid suction chamber 9 through the liquid inlet chamber 10. At this time, due to the positive pressure in the liquid suction chamber 9, the first sealing structure 12 is closed, and the second sealing structure 13 is opened. Since the second sealing structure 13 is unidirectionally conducted from the liquid suction chamber 9 to the liquid discharge chamber 14, the urea in the liquid suction chamber 9 is discharged from the liquid suction chamber 9 to the liquid discharge chamber 14. Figure 1 As shown, the urea flows out from the drainage chamber 14 and passes through the pressure stabilizing chamber structure 2, the throttle valve 3, the third one-way valve 4, and the filter device 7 described below, and then is sprayed out from the first injection pipe and the second injection pipe to achieve two-way injection, thereby increasing the flow rate of urea.

[0040] The suction chamber 9 inside the pump body 1 is only provided with a diaphragm 11, without structures such as a valve core and a valve plate, which greatly simplifies the structure of the device, reduces the production process cost and technical difficulty, and increases the space inside the suction chamber 9, improves the volume ratio, so that the volume of the suction chamber 9 is increased, the negative pressure of the suction chamber 9 is increased, and the double-spray flow rate of urea is further increased; and the inside of the pump body 1 does not need structures such as a valve core and a valve plate to form a negative pressure, and only the diaphragm 11 needs to make a reciprocating motion to realize the process of suction and discharge of the pump body 1, thereby improving the working efficiency; the first sealing structure 12 and the second sealing structure 13 provided can also block impurities in urea, improve the ability to resist impurities and robustness, reduce the failure rate of urea decompression failure, so that the urea pump only needs to be provided with the filtering device 7 described below to meet the cleanliness requirements, and there is no need to provide a pre-filter device, thereby further reducing the cost.

[0041] As a preferred embodiment, a first flow port is formed between the suction chamber 9 and the liquid inlet chamber 10, and urea enters the suction chamber 9 through the first flow port after entering the liquid inlet chamber 10; a second flow port is formed between the suction chamber 9 and the liquid discharge chamber 14, and urea enters the liquid discharge chamber 14 from the suction chamber 9 through the second flow port.

[0042] A flow channel for urea to enter the pump body 1 from the outside is formed between the liquid inlet chamber 10 and the liquid suction chamber 9. The height of the liquid inlet chamber 10 is higher than that of the liquid suction chamber 9 in the flow channel. The connection between the liquid inlet chamber 10 and the liquid suction chamber 9 in the flow channel has an inflection, i.e., a first flow port. The urea passing through the liquid inlet chamber 10 needs to enter the interior of the liquid suction chamber 9 through this first flow port. When the flow rate of urea gradually increases, the diaphragm 11 needs to compress the liquid suction chamber 9 under the driving action of the driving mechanism so that the interior of the liquid suction chamber 9 Positive pressure is gradually formed in the first part. As can be seen from the following, the first flow port is connected with the first sealing structure 12. Under the positive pressure of the liquid, the first sealing structure 12 is closed and the second sealing structure 13 is opened. Urea enters the discharge chamber 14 from the suction chamber 9. The height of the discharge chamber 14 is lower than the height of the inlet chamber 10 but higher than the height of the suction chamber 9. Due to the height difference between the discharge chamber 14 and the suction chamber 9, another inflection is formed, namely the second flow port. Urea enters the discharge chamber 14 from the suction chamber 9 through the second flow port.

[0043] As a preferred embodiment, the first sealing structure 12 adopts a first one-way valve, and the first one-way valve is connected from the liquid inlet chamber 10 to the liquid suction chamber 9; a first spring is connected between the first one-way valve and the liquid inlet chamber 10, so that after urea flows through the liquid inlet chamber 10 to the liquid suction chamber 9, the first flow port is blocked under the elastic force of the first spring.

[0044] The first one-way valve ensures that urea can only flow toward the liquid suction chamber 9 through the liquid inlet chamber 10. When negative pressure is formed in the liquid suction chamber 9, urea in the urea tank flows from the liquid inlet chamber 10 to the liquid suction chamber 9 through the opened first one-way valve. When urea no longer needs to enter the liquid inlet chamber 10, the diaphragm 11 stops expanding, and the first one-way valve can be restored to its initial position under the action of the rebound force of the first spring, thereby realizing that urea is stored in the closed liquid suction chamber 9.

[0045] As a preferred embodiment, the second sealing structure 13 adopts a second one-way valve, and the second one-way valve is connected from the suction chamber 9 to the discharge chamber 14; a second spring is connected between the second one-way valve and the suction chamber 9, so that after urea is discharged from the suction chamber 9 to the discharge chamber 14, the second flow port is blocked under the elastic force of the second spring.

[0046] The second one-way valve ensures that urea can only flow from the suction chamber 9 to the discharge chamber 14 in one direction. When the urea in the suction chamber 9 increases, the diaphragm 11 compresses the suction chamber 9 inwardly, so that the positive pressure in the suction chamber 9 increases. Under the urea hydraulic pressure, the first one-way valve is closed and the second one-way valve is opened. Urea is discharged from the suction chamber 9 to the discharge chamber 14 through the second flow port. After the urea is discharged into the discharge chamber 14, the pressure in the suction chamber 9 decreases, and the second one-way valve returns to its initial position under the action of the rebound force of the second spring.

[0047] As a preferred embodiment, Figure 1 and Figure 4 As shown, the urea pump also includes a pressure-stabilizing chamber structure 2 connected to the drainage chamber 14; the pressure-stabilizing chamber structure 2 includes a protective cover 21; a pressure-stabilizing chamber 22 for pressure compensation of the drainage chamber 14 is formed in the protective cover 21; a pressure compensating member 23 is arranged in the pressure-stabilizing chamber 22, and the pressure compensating member 23 is configured to be compressed by urea and generate a rebound force capable of promoting the output of urea.

[0048] During operation, urea flows out of the liquid discharge cavity 14 and enters the pressure stabilizing cavity 22. The pressure of the liquid flow causes the pressure compensator 23 in the pressure stabilizing cavity 22 to be compressed and deformed. In the initial stage, when urea passes through the pump body 1 and enters the pressure stabilizing cavity structure 2, the pressure compensator 23 in the pressure stabilizing cavity 22 is compressed. At this time, the pressure of the urea has not reached 9 bar. Until the pressure compensator 23 is compressed to the minimum state, the driving mechanism driving the pump body 1 can stop running. The rebound force generated by the rebound of the pressure compensator 23 can provide pressure compensation for the pump body 1 and stabilize the pressure of the entire urea pump, so that the flow range of the urea pump is increased, thereby increasing the flow rate of the liquid. Moreover, since the first injection pipe and the second injection pipe described below have just been started, the driving mechanism at this time has not reached the speed required for work. Therefore, the setting of the pressure stabilizing cavity structure 2 can make its rebound force ensure that the pressure of urea is more stable. The pressure can be stabilized at 9 bar through the control of the PID controller.

[0049] The pressure-stabilizing chamber structure 2 is used to achieve pressure compensation for the urea pump body 1, so that the pressure of the urea pump is more stable; the traditional urea pump is provided with a reflux structure, because the urea pump can work all the time with the reflux structure to ensure pressure stability, and the present application can further achieve pressure stability by setting the pressure-stabilizing chamber structure 2, so there is no need to set the reflux structure; and because there is no reflux structure, the urea pump does not need to work all the time, so the urea pump can stop working when there is no injection demand, and the pump body 1 will work again when there is a sudden injection demand, but the pump body 1 will work suddenly with hysteresis, and the pressure-stabilizing chamber structure 2 can provide pressure compensation to offset the occurrence of this situation; in addition, because there is no reflux structure, when the motor connected to the same urea pump and the size of the diaphragm 11 in the urea pump are the same, the urea flow rate can be further increased, and the injection supply demand of the double-tube urea can be achieved.

[0050] The shape of the pressure compensation member 23 is not particularly limited and may be: Figure 4 The cross-section shown is a diamond-shaped structure, and can also be a spherical structure. The interior of the pressure compensating member 23 is a hollow structure. When the pressure compensating member 23 is compressed inside the pressure stabilizing chamber 22, it is subjected to the pressure of the fluid, and the outside of the pressure compensating member 23 is uniformly squeezed and shrinks inward. When compressed to the minimum state, the pump body 1 stops running. At this time, the pressure compensating member 23 is expanded under the action of its own resilience, thereby achieving pressure compensation for the pump body 1, making the pressure of the urea output more stable, thereby ensuring an increase in the injection flow rate.

[0051] As a preferred embodiment, the protective cover 21 is provided with a water inlet 15 and a water outlet 16 respectively connected to the pressure stabilizing chamber 22; the water inlet 15 is connected to the drainage chamber 14 through a first flow pipe, and the water outlet 16 is connected to the filter device 7 through a second flow pipe.

[0052] During use, urea enters the liquid inlet chamber 10 of the pump body 1 through the urea tank, enters the liquid suction chamber 9, and then flows out from the liquid discharge chamber 14 to the water inlet 15, enters the pressure stabilizing chamber 22, and after pressure compensation, flows out through the water outlet 16 to the filter device 7 to filter impurities.

[0053] As a preferred embodiment, the drainage cavity 14 is provided with a drainage port, and the water inlet 15 is connected to the drainage port through a first flow pipe; the liquid inlet cavity 10 is provided with a liquid inlet, and the liquid inlet is connected to the urea tank through a third flow pipe.

[0054] Urea enters the liquid inlet chamber 10 from the urea tank through the liquid inlet, flows into the liquid discharge chamber 14 after passing through the liquid suction chamber 9, and enters the water inlet 15 through the liquid discharge port of the liquid discharge chamber 14.

[0055] As a preferred embodiment, a pressure sensor 6 is also connected in series to the third circulation pipe, and the pressure sensor 6 is arranged on the downstream side of the filtering device 7; one end of the third circulation pipe provided with the pressure sensor 6 is respectively connected to the first injection pipe and the second injection pipe, and urea is injected through the first injection pipe and the second injection pipe.

[0056] Urea is filtered by the filter device 7 and then enters the first injection pipe and the second injection pipe respectively, and is injected into the mixer through the first injection pipe and the second injection pipe to mix with the high-temperature exhaust gas, thereby causing a catalytic reaction to purify the exhaust gas.

[0057] The present application also relates to an SCR injection system, comprising the above-mentioned dual-injection urea pump, and also comprising a first nozzle 5 and a second nozzle 8; the first injection pipe is connected to the first nozzle 5, the second injection pipe is connected to the second nozzle 8, and urea is injected through the first nozzle 5 and the second nozzle 8 respectively.

[0058] It also includes a controller and a signal processor. The signal processor receives the control parameters of the controller and sends an injection command to the controller. The controller then controls the dual-injection urea pump to absorb urea and inject it into the mixer through the first nozzle 5 and the second nozzle 8, thereby meeting the demand for dual-injection urea.

[0059] The parts not described in the present invention can be realized by adopting or drawing on the existing technology.

[0060] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0061] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A double-spray urea pump, characterized in that: The pump body comprises a liquid suction chamber, a liquid inlet chamber and a liquid discharge chamber; a diaphragm is arranged in the liquid suction chamber; a first sealing structure is arranged between the liquid suction chamber and the liquid inlet chamber, and a second sealing structure is arranged between the liquid suction chamber and the liquid discharge chamber; The first sealing structure is configured such that when the diaphragm is away from the liquid suction chamber so that negative pressure is formed inside the chamber, the first sealing structure opens to allow urea to enter the liquid suction chamber through the liquid inlet chamber; The second sealing structure is configured such that when the diaphragm compresses the liquid absorption chamber to form a positive pressure inside the chamber, the second sealing structure opens to allow urea to be discharged from the liquid absorption chamber through the liquid discharge chamber.

2. A dual-spray urea pump according to claim 1, characterized in that: A first flow port is formed between the suction chamber and the liquid inlet chamber, and urea enters the suction chamber through the first flow port after entering the liquid inlet chamber; a second flow port is formed between the suction chamber and the liquid discharge chamber, and urea enters the liquid discharge chamber from the suction chamber through the second flow port.

3. A dual-spray urea pump according to claim 2, characterized in that: The first sealing structure adopts a first one-way valve, and the first one-way valve is connected from the liquid inlet chamber to the liquid suction chamber; a first spring is connected between the first one-way valve and the liquid inlet chamber, so that after urea flows from the liquid inlet chamber to the liquid suction chamber, the first flow port is blocked under the elastic force of the first spring.

4. A dual-spray urea pump according to claim 2, characterized in that: The second sealing structure adopts a second one-way valve, and the second one-way valve is connected from the suction chamber to the discharge chamber; a second spring is connected between the second one-way valve and the suction chamber, so that after urea is discharged from the suction chamber to the discharge chamber, the second flow port is blocked under the elastic force of the second spring.

5. A dual-spray urea pump according to claim 1, characterized in that: The urea pump also includes a pressure-stabilizing chamber structure connected to the drainage chamber; the pressure-stabilizing chamber structure includes a protective cover; a pressure-stabilizing chamber for pressure compensation of the drainage chamber is formed in the protective cover; a pressure compensating component is arranged in the pressure-stabilizing chamber, and the pressure compensating component is configured to be compressed by urea and generate a rebound force capable of promoting urea output.

6. A dual-spray urea pump according to claim 5, characterized in that: The protective cover is provided with a water inlet and a water outlet respectively connected to the pressure stabilizing cavity; the water inlet is connected to the drainage cavity through a first flow pipe, and the water outlet is connected to the filtering device through a second flow pipe.

7. A dual-spray urea pump according to claim 6, characterized in that: The drainage cavity is provided with a drainage port, and the water inlet is connected to the drainage port through a first flow pipe; the liquid inlet cavity is provided with a liquid inlet, and the liquid inlet is connected to the urea tank through a third flow pipe.

8. A dual-spray urea pump according to claim 7, characterized in that: A throttle valve and a third one-way valve are further connected to the third flow pipe along the flow direction of urea in the third flow pipe, and the throttle valve and the third one-way valve are connected from the water outlet to the filter device.

9. A dual-spray urea pump according to claim 8, characterized in that: The third circulation pipe is also connected in series with a pressure sensor, and the pressure sensor is arranged on the downstream side of the filtering device; the end of the third circulation pipe provided with the pressure sensor is respectively connected to the first injection pipe and the second injection pipe, and urea is injected through the first injection pipe and the second injection pipe.

10. An SCR injection system, characterized in that: A dual-injection urea pump comprising any one of claims 1 to 9, further comprising a first nozzle and a second nozzle; the first injection pipe is connected to the first nozzle, the second injection pipe is connected to the second nozzle, and urea is injected through the first nozzle and the second nozzle respectively.

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