High-pressure fuel depressurization jet pump

Abstract

The invention discloses a high-pressure fuel depressurization jet pump which comprises an inlet connector, a flow limiting inlet, a first channel, a second channel, a flow limiting outlet and a second channel, and the inlet connector is sequentially provided with the flow limiting inlet and the first channel in the first direction, and the diameter of the flow limiting inlet is smaller than that of the first channel; the first direction is the inflow direction of high-pressure fuel oil; the pump body is sequentially provided with a jet pump inlet, a nozzle and a second channel in the first direction, the pump body is further provided with a jet pump suction inlet in the second direction, the tail end of the jet pump suction inlet and an outlet of the nozzle are located in the jet pump cavity, and the second channel sequentially comprises a mixing section and a diffusion section in the first direction; the diameter of the diffusion section is gradually increased in the first direction; and the second direction is the inflow direction of the injected fuel oil. According to the high-pressure fuel jet pump, pressure reduction of high-pressure fuel and speed increase of the high-pressure fuel and injected fuel can be achieved at the same time.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology, and in particular relates to a high-pressure fuel pressure-reducing ejector pump. Background Art

[0002] The aircraft fuel return system is a system that recovers, processes, and reuses used fuel from various parts of the engine and aircraft. On an aircraft, the used fuel is pumped to the engine for combustion, and a portion of the unconsumed fuel flows back to the fuel tank through the fuel return system, where it is filtered and processed and used as fuel again. In addition, when the aircraft is parked, the fuel remaining in the pipeline or fuel tank needs to be recovered through the fuel return system to avoid wasting resources and polluting the environment.

[0003] Many engine oil return systems require the reuse of returned fuel. Reusing returned fuel can reduce the energy consumption of the engine system and improve the efficiency of the engine return system. However, because the returned fuel has the characteristics of high pressure and a wide range, if you want to use the returned fuel, you need to reduce the high-pressure fuel to a low-pressure range to ensure the normal and safe operation of the engine system.

[0004] However, the current ejector pump cannot increase the speed of the return oil and the new fuel in the fuel tank while reducing the pressure of the refluxed high-pressure fuel, thereby achieving the ejection of the return oil and the new fuel. Summary of the invention

[0005] The embodiment of the present invention provides a high-pressure fuel pressure reducing ejector pump, which can solve the problem that the current ejector pump cannot simultaneously reduce the pressure of the refluxed high-pressure fuel and increase the speed of the high-pressure fuel and the new fuel.

[0006] In a first aspect, an embodiment of the present invention provides a high-pressure fuel pressure reduction ejector pump, comprising:

[0007] An inlet joint, wherein the inlet joint is provided with a limited flow inlet and a first channel in sequence along a first direction, wherein the diameter of the limited flow inlet is smaller than the diameter of the first channel; wherein the first direction is the inflow direction of the high-pressure fuel;

[0008] A pump body, wherein the pump body is sequentially provided with an ejector pump inlet, a nozzle and a second channel along the first direction, the pump body is also provided with an ejector pump suction port along the second direction, the end of the ejector pump suction port and the outlet of the nozzle are located in the ejector pump chamber, the second channel sequentially includes a mixing section and a diffusion section along the first direction, and the diameter of the diffusion section gradually increases along the first direction; wherein the first direction is perpendicular to the second direction, and the second direction is the inflow direction of the ejected fuel.

[0009] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the high-pressure fuel pressure-reducing priming pump provided by the present invention can reduce the pressure of the refluxed high-pressure fuel and increase the pressure of the injected fuel by setting a flow-limiting inlet with a smaller inner diameter and a mixing section for mixing the high-pressure fuel and the injected fuel, so that the pressures of both can reach a preset standard; at the same time, by setting a nozzle for spraying high-pressure fuel, the flow rate of the high-pressure fuel can be increased, and the speed of the increased-speed high-pressure fuel can be transmitted to the injected fuel through the mixing section, so that the flow rates of both can also reach a preset standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic structural diagram of a high-pressure fuel pressure reduction ejector pump provided in an embodiment of the present invention;

[0011] Figure 2 A schematic diagram of the structure of an inlet joint provided by an embodiment of the present invention;

[0012] Figure 3 A schematic diagram of the dimensions of an inlet joint provided in an embodiment of the present invention;

[0013] Figure 4 A schematic diagram of the structure of a pump body provided by an embodiment of the present invention;

[0014] Figure 5 A schematic diagram of the dimensions of a diffusion section provided in an embodiment of the present invention;

[0015] Figure 6 A schematic diagram of the specific structure of a high-pressure fuel pressure reduction ejector pump provided by an embodiment of the present invention;

[0016] Figure 7 A schematic diagram of the structure of a one-way valve provided in an embodiment of the present invention;

[0017] Figure 8 A schematic diagram of pressure and flow of an inlet joint provided by an embodiment of the present invention;

[0018] Fig. 9 A schematic diagram of pressure and flow of a pump body provided in an embodiment of the present invention.

[0019] Reference numerals:

[0020] 1: inlet connector; 11: flow limiting inlet; 12: first channel; 2: pump body; 21: jet pump inlet; 22: nozzle; 23: second channel; 231: mixing section; 232: diffusion section; 24: jet pump suction port; 25: jet pump chamber; 3: one-way valve; 31: one-way valve inlet; 32: one-way valve chamber; 321: valve body fixing part; 322: spring; 323: valve body movable part; 33: one-way valve outlet. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0022] Example 1

[0023] Figure 1 The structure diagram of a high-pressure fuel pressure reduction ejector pump provided by an embodiment of the present invention is shown. As an example but not a limitation, the high-pressure fuel pressure reduction ejector pump may include an inlet connector 1 and a pump body 2.

[0024] For example, the inlet connector 1 and the pump body 2 can be arranged along the inflow direction of the high-pressure fuel (see Figure 1 The first direction indicated by the arrow 101 in the middle) is set sequentially.

[0025] Alternatively, see Figure 1 The inlet joint 1 and the pump body 2 can be connected through an oil pipeline.

[0026] In one possible implementation, see Figure 2 , the inlet connector 1 is along the first direction (see Figure 2 The limited flow inlet 11 and the first channel 12 are sequentially arranged in the direction indicated by the middle arrow 201.

[0027] Exemplarily, the diameter of the flow limiting inlet 11 is smaller than the diameter of the first channel 12. Since the pressure of the high-pressure fuel is greater than the upper limit pressure of the engine inlet, the inlet connector 1 can be set to limit the flow of the high-pressure fuel to achieve preliminary pressure reduction of the high-pressure fuel.

[0028] Optionally, the inlet connector 1 may be a specially made stainless steel pipe connector with a limited flow inlet 11 , which can adapt to high pressure environments.

[0029] In one example, if the pressure range of the high-pressure fuel when it flows in is 1.787-5.169 MPa, the flow range is 1315.1-2177.1 L / h, the diameter of the pipe for conveying the return high-pressure fuel is 16 mm, and the first target pressure value of the high-pressure fuel after the flow is limited by the flow limiting inlet 11 is 830 kPa; then refer to Figure 3 The diameter of the flow limiting inlet 11 may be 3 mm, the length may be 11 mm, and the diameter of the first channel may be 16 mm.

[0030] In one possible implementation, see Figure 4 The schematic diagram of the structure and size of the pump body 2 in (a) and Figure 4 The schematic diagram of the structure of the pump body 2 is obtained by abstracting the pump body 2 along the first direction (see Figure 4The pump body 2 is provided with an injection pump inlet 21, a nozzle 22 and a second channel 23 in sequence. The pump body 2 is provided with an injection pump inlet 21, a nozzle 22 and a second channel 23 in the direction indicated by the arrow 401 in the middle. Figure 4 The second channel 23 may include a mixing section 231 and a diffusion section 232, and the diameter of the diffusion section 232 may gradually increase along the first direction.

[0031] Exemplarily, the second direction may be perpendicular to the first direction.

[0032] Specifically, see Figure 1 Figure 2 and Figure 4 The refluxed high-pressure fuel flows in from the flow-limiting inlet 11 of the inlet joint 1, flows through the first channel 12 and the jet pump inlet 21, and is ejected from the nozzle 22. The jetted fuel (i.e., the new fuel in the fuel tank) is sucked in from the jet pump suction port 24.

[0033] For example, the pressure of the high-pressure fuel is greatly reduced when passing through the flow restriction inlet 11, and the speed increases when it is ejected from the nozzle 22. At the same time, the injected fuel is mixed with the high-pressure fuel in the mixing section 231. At this time, the energy of the high-pressure fuel is transferred to the injected fuel by utilizing the change in the injection flow momentum and the diffusion effect of the high-pressure fuel; the pressure of the high-pressure fuel is further reduced, and the flow rate of the injected fuel increases. Finally, the mixed mixed fuel passes through the diffusion section 232, and through the diffusion effect, the flow rate of the mixed fuel exceeding the target flow rate is reduced, and the pressure of the mixed fuel above the second target pressure value is reduced, and it flows into the engine fuel inlet.

[0034] Optionally, the jet pump inlet 21 can be connected to the pipeline for conveying high-pressure fuel through a cone joint with a diameter of 16 mm and a thread specification of M27×1.5. The jet pump suction port 24 can be connected to the pipeline for conveying the injected fuel through a cone joint with a diameter of 22 mm and a thread specification of M33×2, and the second channel 23 can be connected to the pipeline for conveying the mixed fuel through a 74° cone joint with a diameter of 22 mm and a thread specification of M33×2.

[0035] In one example, the outlet cross-sectional area of ​​the nozzle 22 may satisfy the following formula:

[0036]

[0037] Among them, f p1 is the outlet cross-sectional area of ​​the nozzle 22, G p is the target outlet flow rate of the nozzle 22, the unit may be kg / s; is the velocity coefficient at the outlet of the nozzle 22, which can be taken as an empirical value of 0.95;p is the specific volume of high pressure fuel, the unit can be m 3 / kg; Δp p is the pressure increase value in the nozzle 22, and its unit is N / m.

[0038] For example, if the target inlet flow rate of the jet pump suction port 24 is greater than or equal to 2031 L / h (i.e. 1574 kg / h), the target outlet flow rate of the nozzle 22 is 1352 L / h (i.e. 1048 kg / h), ignoring the boost value of the fuel tank of 260 kPa and the density of the high-pressure fuel of 775 kg / m3 (the specific volume of the high-pressure fuel can be obtained from the density); then the outlet cross-sectional area of ​​the nozzle 22 is The outlet diameter d of the nozzle 22 1 ≈4.4mm.

[0039] Optionally, in order to ensure that the high-pressure fuel sprayed from the nozzle 22 maintains a certain direction, a section of a cylinder with a constant diameter is also required to be retained at the outlet of the nozzle 22 (see Figure 4 221), the length of this cylinder can be 0.25d 1 =1.1mm.

[0040] In one example, the cross-sectional area of ​​the mixing section 231 may satisfy the following formula:

[0041]

[0042] Among them, f 3 is the cross-sectional area of ​​the mixing section 231, It represents the ratio of the cross-sectional area of ​​the mixing section 231 to the outlet cross-sectional area of ​​the nozzle, b and c are constants determined according to the target outlet flow of the nozzle 22 and the target inlet flow of the jet pump suction port 24, and a is a constant.

[0043] in:

[0044] b=-[0.975+1.19×(1+u) 2 -0.78u 2 ]

[0045] c=1.19×(1+u) 2

[0046] u=G H / G P

[0047] Among them, G H is the target inlet flow rate of the ejector pump suction port 24, G P is the target outlet flow rate of the nozzle 22.

[0048] For example, if a takes the empirical value of 0.975, and the target inlet flow rate of the ejector pump suction port 24 is 2031 L / h (i.e. 1574 kg / h), then u = G H / G P =(1574-1048)÷1048=0.5, then,

[0049] b=-[0.975+1.19×(1+u) 2 -0.78u 2 ]=-3.4575,c=1.19×(1+u) 2 =

[0050] 2.6775, The cross-sectional area f of the mixing section 231 3 =1.52645×10 -5 ×2.404=3.6696×10 -5 , the diameter d of the mixing section 231 3 It can be 6.8mm.

[0051] In one example, the length of the cylindrical mixing section of the jet pump is usually 6-10 times the diameter of the mixing section, and the length of the throat of the liquid jet pump (i.e., the mixing section) is usually 5-7 times the diameter of the mixing section. If the length of the mixing section is too short, the fluid cannot be mixed evenly, resulting in a very uneven flow velocity distribution at the outlet of the mixing section and increased diffusion losses; on the contrary, if the length of the mixing section is too long, the friction resistance loss will increase. Therefore, in the present invention, the length of the mixing section 231 is set to 6-7 times the diameter of the mixing section, for example, 40.8mm-47.6mm.

[0052] Optionally, in order to minimize the volume of the high-pressure fuel pressure reduction ejector pump, the length of the mixing section 231 may be set to 40.8 mm.

[0053] In one example, the distance l between the outlet of the nozzle 22 and the inlet of the mixing section 231 is c1 The distance between the throat and the nozzle can be calculated based on the length of the free stream ejected from the nozzle 22 and the distance from the nozzle 22 to the nozzle 22. c1 The diameter of the free stream at the position (ie the diameter of the mixing section 231) is determined.

[0054] Generally, the throat-to-mouth distance can be 1-1.5 times the diameter of the mixing section, for example, 6.8 mm-10.2 mm. At different times, the range of throat-mouth distance is:

[0055] Table 1 Relationship between optimal distance and cross-sectional ratio

[0056]

[0057] In the present invention, The value of is generally 2.404, so the throat distance can be 0.5-1.5 times the diameter of the mixing section 231, such as 3.4mm-10.2mm.

[0058] In order to meet the above two requirements at the same time, the throat distance can be 1-1.5 times the diameter of the mixing section 231, such as 3.4mm-10.2mm.

[0059] Optionally, if the second target pressure value of the outlet of the diffuser section 232 is 260 kPa, the throat distance may be set to 8 mm.

[0060] In one example, see Figure 5 The diffusion angle of the diffusion section 232 may range from 2 to 10 degrees. The length of the diffusion section 232 may be determined by the outlet diameter of the diffusion section 232, the diameter of the mixing section 231, and the diffusion angle.

[0061] Exemplarily, the length of the diffuser section 232 may satisfy the following formula:

[0062]

[0063] Among them, l D is the length of the diffuser section 232, d c is the outlet diameter of the diffuser section 232, d 3 is the diameter of the mixing section 231 , and θ is the diffusion angle of the diffusion section 232 .

[0064] For example, when the diffusion angle is 5-8 degrees, the length of the diffusion section 232 is about 7 (d c -d 3 ), for example, 106.4 mm; when the diffusion angle is 8-10 degrees, the length of the diffusion section 232 is about 6-7 times (d c -d 3 ), for example 91.2mm-106.4mm.

[0065] Similarly, if the second target pressure value at the outlet of the diffuser section 232 is 260 kPa, the diffuser angle may be 8 degrees, and the length of the diffuser section 232 may be 108.7 mm.

[0066] Generally, the outlet diameter of the diffuser 232 is determined by the inner diameter of the downstream conduit.

[0067] The high-pressure fuel pressure-reducing priming pump provided by the present invention can reduce the pressure of the refluxed high-pressure fuel and increase the pressure of the injected fuel by providing a flow-limiting inlet with a smaller inner diameter and a mixing section for mixing the high-pressure fuel and the injected fuel, so that the pressures of both can reach a preset standard; at the same time, by providing a nozzle for spraying the high-pressure fuel, the flow rate of the high-pressure fuel can be increased, and the speed of the increased-speed high-pressure fuel can be transmitted to the injected fuel through the mixing section, so that the flow rates of both can also reach a preset standard.

[0068] Furthermore, the pump body provided by the present invention also has the advantages of simple structure, light weight, reliable operation, easy processing, no moving parts and long service life.

[0069] Example 2

[0070] Based on Example 1, Figure 6 The figure shows a specific structural diagram of a high-pressure fuel pressure-reducing ejector pump provided in an embodiment of the present invention.

[0071] For example, see Figure 6 A one-way valve 3 for preventing the reverse flow of high-pressure fuel may also be provided between the inlet connector 1 and the pump body 2 .

[0072] In one possible implementation, see Figure 7 , the one-way valve 3 is along the first direction (see Figure 7 A one-way valve inlet 31, a one-way valve cavity 32 and a one-way valve outlet 33 may be sequentially arranged in the direction indicated by the middle arrow 701. A valve body fixing part 321 is also fixed on the inner wall of the one-way valve cavity 32 near the one-way valve outlet 33, and the valve body fixing part 321 may be connected to the valve body movable part 323 through a spring 322.

[0073] See also Figure 7 When the high-pressure fuel flows in the forward direction (along the first direction), the spring 322 is compressed to push the valve body movable part 323 to the second dead point A2 in the one-way valve cavity 32, so that the one-way valve inlet 31 is unblocked and the high-pressure fuel flows out smoothly. When the high-pressure fuel flows in the reverse direction (along the direction opposite to the first direction), the reverse-flowing fuel will stretch the spring 322 to the first dead point A1 at the one-way valve inlet 31, so that the valve body movable part 323 blocks the one-way valve inlet 31, and the reverse-flowing liquid cannot flow out of the one-way valve inlet 31.

[0074] The high-pressure fuel pressure-reducing priming pump provided by the present invention can reduce the pressure of the refluxed high-pressure fuel and increase the pressure of the injected fuel by providing a flow-limiting inlet with a smaller inner diameter and a mixing section for mixing the high-pressure fuel and the injected fuel, so that the pressures of both can reach a preset standard; at the same time, by providing a nozzle for spraying the high-pressure fuel, the flow rate of the high-pressure fuel can be increased, and the speed of the increased-speed high-pressure fuel can be transmitted to the injected fuel through the mixing section, so that the flow rates of both can also reach a preset standard.

[0075] Furthermore, the present invention facilitates the installation of the one-way valve, the inlet connector and the pump body by independently arranging the one-way valve between the inlet connector and the pump body, rather than directly arranging it inside the pump body; and the one-way valve provided by the present invention has a simple structure and can save space.

[0076] In order to better illustrate the beneficial effects of the present invention, the following simulation experiments were carried out:

[0077] Simulation experiment 1

[0078] Figure 8 Shown is a schematic diagram of pressure and flow of an inlet joint provided in an embodiment of the present invention.

[0079] For example, in simulation experiment 1, the flow rate of the high-pressure fuel flowing into the inlet joint 1 is 2200L / h and the pressure is 5.2Mpa. The first target pressure value of the high-pressure fuel after the flow is limited by the flow limiting inlet 11 is 830kPa. The diameter of the flow limiting inlet 11 is 3mm, the length is 11mm, and the diameter of the first channel is 16mm.

[0080] See also Figure 8 , see Figure 8 , Figure 8 (a) is a pressure simulation diagram obtained by simulating the pressure of the liquid flowing into the inlet joint 1 according to the above parameters. Figure 8 (b) is the velocity simulation diagram. Figure 8 It can be seen that after the refluxed high-pressure fuel flows into the inlet joint 1 of the above specifications, its pressure is reduced from the inflowing 5.86MPa to 0.39MPa-1.15MPa, and the average pressure of the outflowing high-pressure fuel meets the design requirement of 830kPa. It can be seen that the flow-limiting inlet 11 can limit the flow of the high-pressure fuel, thereby greatly reducing the pressure of the high-pressure fuel.

[0081] Simulation experiment 2

[0082] Fig. 9 Shown is a schematic diagram of pressure and flow of a pump body provided in an embodiment of the present invention.

[0083] For example, in simulation experiment 2, the pressure of the high-pressure fuel flowing into the jet pump inlet 21 is 1.15 MPa, the flow rate of the injected fuel flowing into the jet pump suction port 24 is 1410 L / h, the target outlet flow rate of the mixed fuel flowing out of the diffuser section 232 is 3600 L / h, and the second target pressure value of the outlet of the diffuser section 232 is 260 kPa. In the pump body 2, the outlet diameter of the nozzle 22 is 4.4 mm, the diameter of the mixing section 231 is 6.8 mm, the length of the mixing section 231 is 40.8 mm, the throat distance is 8 mm, and the length of the diffuser section 232 is 108.7 mm. In simulation experiment 2, the pressure and flow rate of the fuel flowing through the jet pump inlet 21 (point 1), the jet pump suction port 24 (point 2) and the outlet of the diffuser section 232 (point 3) are recorded respectively, and the following Table 2 can be obtained. At the same time, the pressure and flow rate of the fuel in the pump body 2 are simulated according to the above parameters to obtain Fig. 9 .

[0084] Table 2 High-pressure fuel pressure reduction ejector pump test data record

[0085]

[0086] See also Fig. 9 , Fig. 9 (a) is the pressure simulation diagram. Fig. 9 (b) in the figure is the flow velocity simulation diagram.

[0087] From Table 2 and Fig. 9 As can be seen from (a) in the figure, the pressure of the high-pressure fuel decreases after passing through the mixing section 231, while the pressure of the ejected fuel increases. The pressure of the mixed fuel formed by the two is between 243kPa and 330kPa when it flows out of the diffusion section, and its average value meets the design requirement of 260kPa.

[0088] From Table 2 and Fig. 9 As can be seen from (b) in the figure, the velocity of the high-pressure fuel increases rapidly after being ejected from the nozzle 22, and the momentum is transferred to the ejected fuel after being mixed with the ejected fuel in the mixing section 231, so that the velocity of the mixed fuel flowing out of the diffusion section 232 is increased compared with the high-pressure fuel and the ejected fuel flowing into the pump body 2.

[0089] It can be learned from the comprehensive simulation experiments 1 and 2 that the high-pressure fuel pressure-reducing priming pump provided by the present invention can reduce the pressure of the refluxed high-pressure fuel and increase the pressure of the injected fuel by setting a flow-limiting inlet with a smaller inner diameter and a mixing section for mixing the high-pressure fuel and the injected fuel, so that the pressures of both can reach the preset standards; at the same time, by setting a nozzle for spraying high-pressure fuel, the flow rate of the high-pressure fuel can be increased, and the speed of the increased-speed high-pressure fuel can be transmitted to the injected fuel through the mixing section, so that the flow rates of both can also reach the preset standards.

[0090] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. 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 present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0092] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0093] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, any modifications made without departing from the concept of the present invention should be deemed to belong to the protection scope of the present invention.

Claims

1. A high-pressure fuel pressure-reducing ejector pump, characterized in that: include: An inlet joint 1, wherein the inlet joint 1 is provided with a limited flow inlet 11 and a first channel 12 in sequence along a first direction, wherein the diameter of the limited flow inlet 11 is smaller than the diameter of the first channel 12; wherein the first direction is the inflow direction of the high-pressure fuel; A pump body 2, wherein the pump body 2 is sequentially provided with an ejector pump inlet 21, a nozzle 22 and a second channel 23 along the first direction, and the pump body 2 is further provided with an ejector pump suction port 24 along the second direction, the end of the ejector pump suction port 24 and the outlet of the nozzle 22 are located in an ejector pump chamber 25, and the second channel 23 sequentially includes a mixing section 231 and a diffusion section 232 along the first direction, and the diameter of the diffusion section gradually increases along the first direction; wherein the first direction is perpendicular to the second direction, and the second direction is the inflow direction of the ejected fuel.

2. The high-pressure fuel pressure-reducing ejector pump according to claim 1, characterized in that: A one-way valve 3 is also provided between the inlet connector 1 and the pump body 2 .

3. The high-pressure fuel pressure-reducing ejector pump according to claim 2, characterized in that: The one-way valve 3 is provided with a one-way valve inlet 31, a one-way valve cavity 32 and a one-way valve outlet 33 in sequence along the first direction; A valve body fixing part 321 is fixed on the inner wall of the one-way valve cavity 32 connected to the one-way valve outlet. The valve body fixing part 321 is connected to the valve body movable part 323 through a spring 322. When the valve body movable part 323 moves to a first dead point in the opposite direction of the first direction, it blocks the one-way valve inlet 33.

4. The high-pressure fuel pressure-reducing ejector pump according to claim 1, characterized in that: The outlet cross-sectional area of ​​the nozzle 22 satisfies the following formula: Among them, f p1 is the outlet cross-sectional area of ​​the nozzle 22, G p is the target outlet flow rate of the nozzle 22, is the velocity coefficient of the nozzle outlet, υ p is the specific volume of high-pressure fuel, Δp p The boost value of the nozzle 22.

5. The high-pressure fuel pressure-reducing ejector pump according to claim 4, characterized in that: The cross-sectional area of ​​the mixing section 231 satisfies the following formula: Wherein, f3 is the cross-sectional area of ​​the mixing section 231, represents the ratio of the cross-sectional area of ​​the mixing section 231 to the outlet cross-sectional area of ​​the nozzle 22, b and c are constants determined according to the target outlet flow of the nozzle 22 and the target inlet flow of the jet pump suction port 24, and a is a constant.

6. The high-pressure fuel pressure-reducing ejector pump according to claim 5, characterized in that: The length of the mixing section 231 is 6-7 times the diameter of the mixing section 231 .

7. The high-pressure fuel pressure-reducing ejector pump according to claim 1, characterized in that: The throat distance is 1-1.5 times the diameter of the mixing section 231 , and the throat distance is the distance between the mixing section 231 and the nozzle 22 .

8. The high-pressure fuel pressure-reducing ejector pump according to claim 1, characterized in that: The diffusion angle of the diffusion section 232 ranges from 2 to 10 degrees.

9. The high-pressure fuel pressure-reducing ejector pump according to claim 8, characterized in that: The length of the diffusion section 232 satisfies the following formula: Among them, l D is the length of the diffusion section 232, d c is the outlet diameter of the diffusion section 232 , d3 is the diameter of the mixing section 231 , and θ is the diffusion angle of the diffusion section 232 .

10. The high-pressure fuel pressure-reducing ejector pump according to any one of claims 1 to 9, characterized in that: The outlet diameter of the nozzle 22 is 4.4 mm, the diameter of the mixing section 231 is 6.8 mm, the length of the mixing section 231 is 40.8 mm, the throat distance is 8 mm, and the length of the diffusion section 232 is 108.7 mm.

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