Dual-fuel constant-volume combustion bomb with adjustable injection angle and injection angle adjusting method of dual-fuel constant-volume combustion bomb

Abstract

The invention discloses a dual-fuel constant-volume combustion bomb capable of adjusting an injection angle and an injection angle adjusting method of the dual-fuel constant-volume combustion bomb. The dual-fuel constant-volume combustion bomb is provided with an injection angle adjusting device, the injection angle adjusting device comprises bushings installed in a ball-table-shaped cavity reserved between the top of a bomb containing cavity and a bomb containing upper cover plate, and two fuel injectors are installed on the corresponding bushings and sealed through rubber sealing plugs and pressing discs. Therefore, on one hand, cooling liquid flows into and out of the cavity of the lining to cool the fuel injector, and on the other hand, the fuel injection angle of the fuel injector can be flexibly adjusted by rotating the fuel injector. According to the invention, bidirectional cooperative multi-angle adjustment of liquid / liquid and liquid / gas fuel injection at the top of the bomb cavity can be realized in the spraying and combustion process in a dual-fuel dual-injection fuel supply mode.

Description

Technical Field

[0001] The invention belongs to the technical field of alternative fuel spray and combustion, and relates to a high-temperature and high-pressure constant-volume combustion bomb with adjustable fuel injection angle and a method for adjusting the fuel injection angle. Background Art

[0002] The combustion of fuel and the study of chemical reaction kinetics are the basis for the development of dual-fuel engines, and the constant volume combustion bomb is an important device for conducting these studies. The traditional high-temperature and high-pressure constant volume combustion bomb only has a high-pressure common rail fuel injector installed on the top of the bomb cavity, and a cylindrical cavity formed by the hollow part of the bomb cavity is used to simulate the high-temperature and high-pressure environment of the internal combustion engine combustion chamber, and the side of the bomb cavity is usually left with four cylindrical windows, front, rear, left and right, so that the spray and combustion characteristics of a single fuel (such as diesel and gasoline) can be studied. The dual-fuel dual-injection constant volume combustion bomb developed and manufactured for alternative fuels to diesel and gasoline can achieve fuel mixing and combustion of dual-fuel dual injection, but when the fuel injection angle of the two fuel injectors is fixed (and cannot be adjusted), it is impossible to carry out dual-fuel multi-angle injection research (such as CN116481819A).

[0003] For most alternative fuels in the dual-fuel dual-injection fuel supply mode, there is a need for in-depth research on injection at different angles. For example, a dynamic cooperative combustion method that can better exert the respective advantages of the two fuels can be proposed through research to improve combustion efficiency and substitution rate (generally, the injection angle will not be easily changed during an experiment. The angle adjustment is carried out in the preparation stage before the experiment, when the temperature and pressure in the bomb chamber are normal; but it is often impossible to determine a more ideal injection angle in one experiment). For this purpose, CN113586301A proposes a dual-fuel injection device, which has two nozzle clamping and fixing units that are relatively arranged and can swing along a semicircular track with a scale, and the nozzle clamping and fixing units and the semicircular track can move up and down as a whole, thereby realizing the adjustment of the angle and relative position of the two nozzle adapter units; however, the dual-fuel injection device is mainly suitable for an open experimental environment, and its nozzle clamping and fixing unit relies on an open space for angle adjustment, and is not suitable for installation and application in an experimental system in a closed environment, and cannot provide a high-temperature and high-pressure environment similar to a bomb (air and other environmental gases are injected into the bomb cavity at the beginning of the experiment, thereby causing the pressure to rise, and the inside of the bomb cavity can be heated so that the injected fuel can be burned at high temperature), and thus cannot meet the needs of multi-angle injection experiments in a closed environment; and its nozzle clamping and fixing unit is fixed and adjusted by a hexagonal nut and a connector, and although the injection angle of the nozzle adapter unit can be adjusted within a certain range, it cannot be directly adapted to the installation and sealing conditions on a constant-volume combustion bomb used to simulate a high-pressure combustion chamber of an internal combustion engine.

[0004] In addition, CN208418714U proposes a variable injection angle nozzle, but due to the limitation of the angle adjustment method, it is only used in industrial furnaces and has not been applied to fuel supply in a closed environment. CN111527267A proposes a ball joint, which avoids the influence of machining debris on the sealing effect by modifying the mounting structure of the annular sealing component between the retaining element and the cavity of the second connecting component (specifically, using the first annular shoulder and the embedded component to form an annular groove), but the ball joint is used for low-pressure fluid delivery, the angle adjustment range is limited, and the direction during adjustment cannot be accurately controlled. Summary of the invention

[0005] The purpose of the present invention is to provide a dual-fuel constant volume combustion bomb with adjustable injection angle and a method for adjusting the injection angle thereof, so as to ensure the sealing of the bomb under high pressure (and high temperature) conditions and to flexibly adjust the injection angle of the dual fuel within a larger range.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A dual-fuel constant-volume combustion bomb with adjustable injection angle comprises a bomb chamber, a bomb upper cover plate and an injection angle adjustment device, wherein the injection angle adjustment device comprises a bushing arranged in a spherical table-shaped cavity reserved between the top of the bomb chamber and the bomb upper cover plate and used for adjusting the fuel injection angle of an injector fixed thereto in the top of the bomb chamber by rotating itself.

[0007] Preferably, two hemispherical concave mounting grooves are symmetrically arranged on the top of the bullet-containing cavity, and the two concave mounting grooves pass through the top of the bullet-containing cavity (that is, the concave mounting grooves are nearly hemispherical); two hemispherical upper concave mounting grooves are symmetrically arranged on the bottom of the bullet-containing upper cover plate (specifically on a boss), and the two upper concave mounting grooves pass through the bullet-containing upper cover plate (that is, the upper concave mounting grooves are nearly hemispherical); sealing ring grooves are arranged on the circumference of the inner walls of the upper and lower concave mounting grooves, and each bushing (specifically two bushings) is in contact with the upper and lower concave mounting grooves corresponding to the outer sides thereof, and sealing rings are arranged in the corresponding sealing ring grooves on the upper and lower concave mounting grooves (that is, the upper and lower concave mounting grooves form the spherical table-shaped cavity between the top of the bullet-containing cavity and the bullet-containing upper cover plate to install the bushing and are sealed through multiple sealing rings).

[0008] Preferably, the bullet-containing upper cover plate is fixed to the top of the bullet-containing cavity by bolts, and the two hemispherical concave mounting grooves are arranged on the bottom of a groove structure (referred to as positioning groove) on the top of the bullet-containing cavity for engaging and positioning with the above-mentioned boss.

[0009] Preferably, a limit block for limiting the rotation direction of the bushing and the rotation angle in the rotation direction is provided on the bullet-proof upper cover plate.

[0010] Preferably, the injection angle adjustment device also includes an end cover pressure plate, a sealing rubber plug and an angle pointer that rotates synchronously with the bushing. The sealing rubber plug is in close contact with the end cover pressure plate. A space for the circulation of coolant is reserved between the sealing rubber plug and the bushing. The injector penetrates the sealing rubber plug and the space for the circulation of coolant and is pressed against the bushing through the end cover pressure plate.

[0011] Preferably, the angle pointer is arranged on the injector via a buckle fastened to the injector, that is, each injector (specifically two injectors) is connected to the corresponding angle pointer via the buckle.

[0012] Preferably, two angle scales arranged in a collinear manner (i.e., arranged in a straight line) are provided on the upper cover plate of the bomb container, each angle scale is provided with an arc groove and a scale for indicating the rotation angle of the bushing (i.e., the fuel injection angle of the injector fixed on the corresponding bushing), and each angle pointer penetrates into the arc groove on the corresponding angle scale.

[0013] Preferably, the scale on the angle scale is between 75 and 40 degrees, that is, the fuel injection angle of each injector is adjusted between 15 and 50 degrees. Preferably, the end cover pressure plate is fixed to the inner cavity of the bushing by bolts, and a slot for positioning the injector is provided on the end cover pressure plate.

[0014] Preferably, a coolant inlet pipe and a coolant outlet pipe are provided on the end cover pressure plate through a sealing rubber plug, one end of the coolant inlet pipe and the coolant outlet pipe are located in the space for the circulation of the coolant, and the other end of the coolant inlet pipe and the coolant outlet pipe penetrates the sealing rubber plug and extends in a direction away from the space for the circulation of the coolant.

[0015] Preferably, there is a length difference between the portions of the coolant inlet pipe and the coolant outlet pipe located in the space for circulating the coolant.

[0016] Preferably, the sealing rubber plug includes a plug body and a sealing cover for contacting and cooperating with the end cover pressure plate, the sealing cover is connected to one end of the plug body, and the sealing cover and the plug body are provided with through holes for the injector, the coolant inlet pipe and the coolant outlet pipe to pass through, the wall surface of the plug body in contact with the injector is provided with multiple sealing rings arranged at intervals in the circumferential direction, and the wall surface of the plug body in contact with the inner cavity of the bushing is provided with multiple sealing rings arranged at intervals in the circumferential direction.

[0017] A method for adjusting the fuel injection angle of a dual-fuel constant volume combustion bomb comprises the following steps: The two injectors are symmetrically installed in the top of the bullet-containing cavity through the above-mentioned injection angle adjustment device, and the fuel injection angle of the injector fixed with it (referring to the bushing) is adjusted by rotating the bushing of the injection angle adjustment device, wherein the fuel injection angle is adjusted between 15 and 50 degrees to flexibly change the spray collision angle of the two injectors.

[0018] Preferably, the spray collision angle of the two injectors can be flexibly changed between 30 and 100 degrees.

[0019] Preferably, the fuel injection angles of the two injectors are adjusted to 20 to 35 degrees. Preferably, the intersection point of the spray collision is always located within the field of view of the observation window at the upper part of the bullet-containing cavity.

[0020] Preferably, the fuel injection angle is indicated by an angle pointer connected to the injector and with the aid of an angle scale. The beneficial effects of the present invention are embodied in: The present invention utilizes a spherical table-shaped cavity reserved between the top of a bomb container and an upper cover plate of the bomb container to install an injection angle adjustment device, and can change the fuel injection angle of an injector fixed to a bushing of the injection angle adjustment device within a relatively large range, thereby meeting the need for conducting fuel multi-angle injection experiments in the process of realizing liquid / liquid and liquid / gas fuel spraying and combustion using a bomb container.

[0021] Furthermore, the bushing in the present invention rotates synchronously with the injector, and its fuel injection angle can be adjusted by touching the injector (that is, there is no need to independently operate the bushing during adjustment), thereby improving the flexibility of adjustment. Furthermore, although the multiple sealing rings on the upper concave mounting groove and the lower concave mounting groove in the present invention increase a certain friction force in a high-pressure environment (which effectively avoids the leakage of fuel and gas in the bullet-containing cavity), thanks to the upper and lower spherical surface design on the outside of the bushing, the pressure can be evenly distributed, and the friction force will not be too large to hinder the rotation of the bushing, ensuring that even under high-pressure conditions, the injector can still rotate flexibly to adjust the fuel injection angle.

[0022] Furthermore, the sealing rubber plug in the present invention is provided with multiple sealing rings on the inner wall surface in contact with the injector, which effectively solves the problem of leakage of the coolant during the experiment.

[0023] Furthermore, the coolant circulation in the present invention ensures the working stability of the bomb container (for example, the injector is effectively cooled during the injection of fuel) on the one hand, and reduces the local (for example, the bushing) thermal expansion changes caused by the fuel combustion in the experiment on the other hand, avoiding excessive friction obstruction, and ensuring that the fuel injection angle can still be flexibly adjusted under the internal high temperature and high pressure environment and sealing conditions (for example, adjusted to the predetermined fuel injection angle for the next experiment), thereby improving the experimental efficiency.

[0024] Furthermore, in the dual injection mode, the present invention can make the two injectors form a better intersection of spray collision in the central area of ​​the bomb cavity by selecting a fuel injection angle of 20 to 35 degrees (the angle range of 20 to 35 degrees can effectively ensure that the spray of the injector will not be over-dispersed or over-concentrated, achieving a more ideal spray collision effect), ensuring uniform distribution and sufficient combustion of the fuel, which is not only convenient for observation, but also improves the accuracy and reliability of the experimental results; if the fuel injection angle is too large, the spray will deviate to the edge of the bomb cavity, resulting in incomplete combustion or local overheating, and if the fuel injection angle is too small, it will lead to insufficient spray coverage, affecting the uniformity of the fuel and its mixing with the gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1-1 It is a schematic diagram of the structure of a dual-fuel constant volume combustion bomb with adjustable injection angle; Figure 1-2 This is a partial enlarged view of a dual-fuel constant volume combustion bomb with adjustable injection angle; Figure 2-1 It is a top view of the bullet-containing cavity; Figure 2-2 is a cross-sectional view of the bullet-containing cavity; Figure 3-1 It is a top view of the upper cover plate of the bomb container; Figure 3-2 It is a cross-sectional view of the upper cover plate of the bomb container; Figure 4 It is a structural schematic diagram of the injection angle adjustment device; Figure 5-1 for Figure 4 a top view of the bushing shown; Figure 5-2 for Figure 4 a cross-sectional view of the bushing shown; Figure 6-1 for Figure 4 A top view of the sealing rubber plug shown; Figure 6-2 for Figure 4 A cross-sectional view of the sealing rubber plug shown; Figure 7-1 for Figure 4 A top view of the pressure plate shown; Figure 7-2 for Figure 4 a cross-sectional view of the pressure plate shown; Figure 8 for Figure 4 A schematic diagram of the structure of the fuel injector shown; Figure 9-1 for Figure 4 A top view of the angle pointer and pointer mounting buckle shown; Figure 9-2 for Figure 4 The left side view of the angle pointer and pointer mounting buckle shown; Fig.10 Orthogonal observation diagram of the two-way adjustment mode of fuel injection angle (the spray collision angle is in the range of 30 to 100 degrees, and in general, the injectors on both sides are selected to deflect to the middle at the same angle during the experiment); In the figure: 1-bullet container; 2-lower mounting groove; 3-lower sealing ring mounting groove; 4-bullet container upper cover plate; 5-upper mounting groove; 6-limiting block; 7-upper sealing ring mounting groove; 8-angle scale; 9-angle pointer limiting groove; 10-bushing; 11-fuel injector; 12-pressure plate; 13-sealing rubber plug; 14-coolant inlet pipe; 15-coolant outlet pipe; 16-threaded hole; 17-through hole; 18-inner positioning boss; 19-rear end face ; 20-coolant pipeline through hole; 21-fuel injector through hole; 22-sealing cover; 23-outer sealing ring; 24-inner sealing ring; 25-plug body; 26-coolant pipeline mounting hole; 27-positioning mounting hole; 28-slot; 29-pressing groove; 30-gasket; 31-angle pointer; 32-pointer mounting buckle; 33-slot fixing hole; 34-orthogonal observation window; 35-parallel observation window; 36-positioning groove; 37-external positioning boss. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The embodiments are only used to explain the present invention, but not to limit the scope of protection of the present invention.

[0027] 1. Structure of dual-fuel constant volume combustion bomb See also Figure 1-1 The present invention optimizes the design of the injection angle adjustment device and the installation position for the two fuel injectors 11 of the dual-fuel constant volume combustion bomb, and proposes a dual-fuel constant volume combustion bomb with adjustable injection angle. The injection angle adjustment device is installed between the top of the bomb chamber 1 and the upper cover plate 4 of the bomb chamber. Through a pair of injection angle adjustment devices, the fuel injection angle of the corresponding fuel injector 11 installed on the two injection angle adjustment devices can be changed individually or simultaneously, and the state of the liquid / liquid or liquid / gas fuel mixing and combustion process under the dual-fuel dual-injection fuel supply mode on the top of the bomb chamber 1 can be observed in the fixed (pre-set or adjusted between different experiments in succession) dual-fuel injection angle (i.e., fixed spray collision angle) experiment (different observation windows can be selected for observation, such as observation along the orthogonal observation window 34, i.e., observation in the direction perpendicular to the plane where the two fuel injectors 11 are located; or observation can be selected along the parallel observation window 35, i.e., observation in the direction parallel to the plane where the two fuel injectors 11 are located).

[0028] See also Figure 1-2 The injection angle adjustment device includes a bushing 10, which is specifically installed in a spherical cavity formed by a reserved installation groove on the top of the bullet-containing cavity 1 and a reserved installation groove on the bottom of the bullet-containing upper cover plate 4. The cavity is compressed and sealed by bolts on the bullet-containing upper cover plate 4 and the top of the bullet-containing cavity 1, and frictionally sealed with sealing rings arranged in the two upper and lower mounting grooves. The fuel injection angle can be adjusted by directly rotating the fuel injector 11 installed on the bushing 10 through a touch operation, and the fuel injection angle can be specifically indicated on the angle scale 8 by the synchronous rotation of the angle pointer 31. By using the limit block 6 to limit the rotation direction of the fuel injector 11 to overlap with the center line of the two parallel observation windows 35, and combining the two fuel injectors 11 (for example, both are electric injectors) colinearly rotating in opposite directions (that is, one rotates clockwise and the other rotates counterclockwise, and the nozzles of the two fuel injectors 11 are rotated toward the middle) from the initial position (that is, the fuel injection angle with an angle of 0° with the plumb direction) to the same angle (usually it can be freely adjusted to the required fuel injection angle when the rotation does not exceed 50°) and the injection pressure is the same at the same time, the intersection of the spray collision formed by the injected fuel of the two fuel injectors 11 must be located at the center of the bomb chamber 1, that is, the two spherical table-shaped cavities are symmetrically distributed relative to the center line of the two orthogonal observation windows 34, so that the positions of the two spherical table-shaped cavities can be determined as a whole.

[0029] See also Figure 2-1 as well as Figure 2-2 The side wall of the bomb chamber 1 is provided with four cylindrical observation windows of the same height (i.e., arranged at the same height on the upper part of the bomb chamber 1) and evenly spaced (i.e., the constant volume combustion bomb has four circular transparent windows, two of which are used for orthogonal observation of the fuel mixing and combustion process in the dual injection mode, and the other two are used for parallel observation of the fuel mixing and combustion process in the dual injection mode), a positioning groove 36 is provided at the center of the top of the bomb chamber 1, and two nearly hemispherical mounting grooves (specifically, a concave hemispherical shape without a spherical crown, referred to as lower mounting grooves 2) that penetrate the top of the bomb chamber 1 and are symmetrically distributed are provided at the bottom of the positioning groove 36, and a number of sealing ring mounting grooves (called lower sealing ring mounting grooves 3) that are evenly spaced are provided on the inner wall of the mounting groove. See also Figure 3-1 as well as Figure 3-2The bottom center of the upper cover plate 4 of the bullet container is provided with an external positioning boss 37, and the external positioning boss 37 is provided with two nearly hemispherical mounting grooves (specifically, an upper concave hemispherical shape without a spherical cap, called upper mounting grooves 5) that penetrate the upper cover plate 4 and are symmetrically distributed. The inner wall of the mounting groove is provided with several sealing ring mounting grooves (called upper sealing ring mounting grooves 7) that are evenly spaced and distributed in the circumferential direction. There are two angle scales 8, which are respectively provided at the top of the upper cover plate 4 of the bullet container and are tangent to one side of the circular opening of the two upper mounting grooves 5 at the top of the upper cover plate 4 (either side parallel to the rotation direction of the fuel injector 11) (such as Figure 3-2 As shown, the two angle scales 8 are perpendicular to the upper cover plate 4 of the bullet container. Figure 3-1 As shown, the two angle scales 8 are coplanar and thus tangent to the corresponding circular opening on the same side), each angle scale 8 is provided with an arc-shaped angle pointer limit groove 9 (the limitation here means that the angle pointer 31 can only rotate in one direction from the initial position of the fuel injector 11, and the maximum rotation angle is set) and angle scales arranged along the arc-shaped angle pointer limit groove 9 to mark the rotation angle of the corresponding fuel injector 11 from the initial position (for example, when the angle pointer deflects to the angle scale of 75 degrees, the fuel injector rotates by 15 degrees; when the angle pointer deflects to the angle scale of 40 degrees, the fuel injector rotates by 50 degrees), one end of the angle pointer 31 is connected to the fuel injector 11, and the other end extends and penetrates into the arc-shaped angle pointer limit groove 9 on the corresponding angle scale 8. There are two limit blocks 6, which are respectively arranged on the top of the upper cover plate 4 of the bomb container and cross the corresponding upper installation grooves 5 along the two upper installation grooves 5 on one side of the circular opening of the top of the upper cover plate 4 of the bomb container (the side perpendicular to the rotation direction of the fuel injector 11 and away from the opposite circular opening) to limit the rotation of the fuel injector 11 and its bushing 10 in other directions. As the bolts on the top of the bomb container cavity 1 pass through the screw holes at the corresponding positions on the upper cover plate 4 of the bomb container, and the outer positioning boss 37 on the bottom of the upper cover plate 4 of the bomb container is inserted into the positioning groove 36, the upper cover plate 4 of the bomb container and the top of the bomb container cavity 1 are integrally fitted, and the two upper installation grooves 5 and the two lower installation grooves 2 respectively form two spherical table-shaped cavities for installing a pair of injection angle adjustment devices.

[0030] See also Figure 4The injection angle adjustment device also includes an end cover pressure plate 12, a sealing rubber plug 13, a coolant inlet pipe 14 and a coolant outlet pipe 15. The overall shape of the bushing 10 is a spherical cylinder (the outer contour of the bushing 10, that is, the upper and lower bottom surfaces and the side surfaces are adapted to the spherical table-shaped cavity shape provided between the top of the bullet-containing cavity 1 and the bullet-containing upper cover plate 4). The sealing rubber plug 13 and the fuel injector 11 are fixed to the bushing 10 as a whole through the end cover pressure plate 12 (located on the upper bottom surface side of the bushing 10). The fuel injector 11 passes through the sealing rubber plug 13 as a whole. and the center of the bushing 10, and the nozzle of the fuel injector 11 extends out of the bushing 10 (located on the lower bottom surface side of the bushing 10), so that a certain closed space is formed in the inner cavity of the bushing 10 by using the sealing rubber plug 13 to accommodate the coolant, and the coolant flows into and out of the closed space through the coolant inlet pipe 14 and the coolant outlet pipe 15 installed on both sides of the fuel injector 11 and penetrating the sealing rubber plug 13, so that the coolant is in a flowing state around the fuel injector 11 (specifically the end where the nozzle is located), thereby achieving the purpose of cooling the fuel injector 11. The angle pointer 31 is connected to the other end of the fuel injector 11 through the pointer mounting buckle 32. In addition, considering that the closed space surrounds the fuel injector 11 and is a connected whole, with reference to CN116481819A, the lengths of the coolant inlet pipe 14 and the coolant outlet pipe 15 extending into the closed space are set to be different, so that the coolant entering the closed space starts from the lower half of the closed space where the fuel injector 11 is located, gradually flows radially to the upper half of the closed space where the fuel injector 11 is located, and then flows out, thereby ensuring the cooling effect.

[0031] In the present invention, when the fuel injector 11 is installed in the spherical cavity between the top of the bomb container 1 and the bomb container upper cover plate 4 by using the injection angle adjustment device, the bolts on the top of the bomb container 1 are mainly used to complete the fixation and the compression and sealing of the upper and lower installation grooves 5 and 2. In order to enable the fuel injector 11 to be assembled simply and accurately and work reliably and effectively (including adjusting the fuel injection angle and injecting fuel in the top of the bomb container 1), the injection angle adjustment device is specifically designed as follows: In order to ensure that the bushing 10 can rotate flexibly in the spherical cavity between the top of the bullet-containing cavity 1 and the bullet-containing upper cover plate 4 and ensure sealing, the outer side surface of the bushing 10 is designed to be a curved surface intercepted from a spherical surface (such as Figure 5-1 , Figure 5-2As shown in the figure, after the upper cover plate 4 is installed on the top of the bullet-containing cavity 1 by bolts and tightened with nuts, the spherical table-shaped cavity outside the bushing 10 is applied with an axial force, so that the lower half of the outer side surface of the bushing 10 contacts the lower mounting groove 2 at the top of the bullet-containing cavity 1, and the upper half of the outer side surface of the bushing 10 contacts the upper mounting groove 5 at the outer positioning boss 37 at the bottom of the upper cover plate 4, so as to cooperate with the sealing rings in the upper and lower mounting grooves 5 and 2 to achieve sealing; for the fuel injection angle adjustment performed before the experiment, the pressure in the bullet-containing cavity 1 is relatively small at this time, and the sealing system (including the above-mentioned sealing ring) has little effect on the flexibility of adjustment. When the pressure in the bullet-containing cavity 1 rises during the experiment (usually due to the injection of ambient gas), a vertical upward force is applied to the bushing 10 to make the bushing 10 further close to the spherical table-shaped cavity outside it and the sealing ring provided in the cavity (specifically located in the upper sealing ring mounting groove 7 and the lower sealing ring mounting groove 3). At this time, the fuel injection angle is adjusted by increasing the sealing performance through friction with the sealing ring. In addition, by tightening the upper cover plate 4 of the bullet-containing chamber through bolts and nuts, the sealing effect can be increased. Especially when the pressure in the bullet-containing chamber 1 rises, the sealing system will further enhance the sealing of the bullet-containing chamber 1.

[0032] In order to ensure that the sealing rubber plug 13, the coolant inlet pipe 14, and the coolant outlet pipe 15 can be installed simultaneously with the fuel injector 11, the inner cavity of the bushing 10 is designed as a stepped cavity (such as Figure 5-2 As shown), and according to the nozzle diameter φ of the fuel injector 11 p1 A hole with a diameter of φ is opened at the center of the bottom surface of the bushing 10 c1 The through hole 17 is provided so that the nozzle (B section of the fuel injector 11, such as Figure 8 as shown) protrudes from the bushing 10 (eg φ c1 Larger than the nozzle diameter φ p1 0.5~1mm); according to the A section of the fuel injector 11 (such as Figure 8 As shown) axial length, combined with the sealing cover 22 (as shown) on the upper part of the sealing rubber plug 13 Figure 6-2 Thickness H S Design diameter φ c2 The axial dimension of the cooling liquid chamber (communicated with the through hole 17 and used to form the above-mentioned closed space after being combined with the lower part of the sealing rubber plug 13) (for example, the axial length of the cooling liquid chamber is equal to the thickness H of the sealing cover 22) S The sum of the lengths is equal to the axial length of section A of the fuel injector 11); the radial dimension of the remaining portion of the inner cavity of the bushing 10 is increased (the inner cavity portion of the bushing 10 with the largest diameter), and is connected to the coolant cavity, and an inner positioning boss 18 for assembling the end cover pressure plate 12 is formed on the outer side of the end surface of the coolant cavity, and four centrally symmetrical threaded holes 16 are opened on the inner positioning boss 18 (such as Figure 5-1 The sealing rubber plug 13 is designed as a stepped type (as shown). Figure 6-2As shown in the figure, a coolant sealing structure with a friction seal and a compression seal is adopted to ensure the sealed isolation state between the coolant cavity (specifically the above-mentioned closed space) and the remaining part of the inner cavity of the bushing 10 after the sealing rubber plug 13 is installed between the fuel injector 11 and the bushing 10, and to prevent the coolant sealing structure from failing due to heat rise and other reasons. The sealing rubber plug 13 not only provides sealing for the coolant, but also forms a cooling circuit in the sealing cavity (i.e. the above-mentioned closed space) through the circulation of the coolant, thereby maintaining the working stability of the fuel injector 11 under high temperature and high pressure. The bushing 10 allows the fuel injector 11 to adjust the fuel injection angle by rotation under sealed conditions, and the circulation of the coolant effectively reduces the friction caused by local thermal expansion, ensuring that the fuel injection angle can still be flexibly adjusted under high temperature and high pressure environments.

[0033] The lower part of the sealing rubber plug 13 has a diameter of φ s3 , and is larger than the coolant cavity diameter φ c2 The plug body 25 has a diameter of 0.5 to 1 mm, and a plurality of outer sealing rings 23 (such as Figure 6-2 As shown), the plug body 25 is tightly combined with the inner wall of the coolant cavity after being fully embedded in the coolant cavity, and axially fastens the coolant inlet pipe and the coolant outlet pipe 14, 15. The sealing cover 22 is adjacent to the upper side of the plug body 25 (for example, the sealing cover 22 and the plug body 25 are connected as a whole), and its diameter φ s4 Greater than φ s3 5~10mm, and less than the minimum length from the center of the threaded hole 16 opened on the inner positioning boss 18 to the center of the bushing 10 (to prevent the sealing cover 22 from blocking the threaded hole 16 after being close to the inner positioning boss 18), so as to facilitate the pressing and installation of the end cover pressure plate 12, and the center of the sealing rubber plug 13 is punched (called the fuel injector through hole 21, the hole diameter φ s1 ,like Figure 6-1 as shown), and according to the diameter φ of the fuel injector 11 p2 (The radial dimension of the portion of the fuel injector 11 that passes through the fuel injector through hole 21 is taken as the injector diameter φ p2 ,like Figure 8 Design aperture (diameter) φ s1 Less than φ p2 1~3mm, multiple inner sealing rings 24 (such as Figure 6-2 As shown), a hole is punched on each side of the fuel injector through hole 21 on the sealing rubber plug 13 (collectively referred to as the coolant pipeline through hole 20, with a hole diameter of φ s2 ,like Figure 6-1 As shown in the figure), the diameter of the coolant pipe (specifically the coolant inlet pipe and the coolant outlet pipe 14, 15) is designed as φ s2 0.5 to 1 mm smaller than the outer diameter of the corresponding coolant pipe.

[0034] In order to ensure that the fuel injector 11 is fixed on the bushing 10 while the sealing rubber plug 13 is pressed, the diameter of the end cover pressure plate 12 is designed to be y1 The end cover plate 12 has a groove (called a card groove 28) radially extending from the edge, which is smaller than the maximum diameter of the inner cavity of the bushing 10 by 5 to 8 mm. The groove depth is greater than the radius of the end cover plate 12 and the groove width L y ,like Figure 7-1 As shown), according to the pressure groove 29 on the fuel injector 11 (the portion of the A section of the fuel injector 11 that passes through the fuel injector through hole 21, as shown in FIG. Figure 8 Width L p , Design L y Greater than L p 1~2mm, the bottom of the slot 28 is arc-shaped so as to be close to the outer surface of the pressing groove 29, and the arc radius R y According to the diameter φ p2 Design, and the end cover platen 12 thickness H y Smaller than the axial length H of the groove 29 P (like Figure 7-2 , Figure 8 According to the threaded hole 16 opened on the inner positioning boss 18, a positioning mounting hole 27 is opened on the end cover pressure plate 12 (as shown); Figure 7-1 As shown), the aperture of the positioning mounting hole 27 is φ y2 The diameter of the threaded hole 16 is the same as that of the threaded hole 16 and is 2 mm larger than the diameter of the bolt used to assemble the end cover platen 12; a coolant pipe installation hole 26 is opened on the end cover platen 12 according to the coolant pipe through hole 20 on the sealing rubber plug 13 (the center of the punching position is aligned with the center line of the card slot 28, and the card slot 28 respectively provides two penetration assembly positions required for the coolant inlet pipe and the coolant outlet pipe 14, 15, such as Figure 7-1 As shown), and the diameter of the coolant pipe mounting hole 26 is φ y3 Greater than φ s2 1~2mm.

[0035] In order to ensure that the angle pointer 31 can indicate the corresponding angle scale after the fuel injector 11 is rotated, and the spray collision angle can be determined according to the corresponding angle scales of the two fuel injectors 11, the angle pointer 31 is designed as a cylinder as a whole, and its diameter is slightly smaller than the width of the angle pointer limiting groove 9 on the angle scale 8 by 0.5-1 mm, that is, the head of the angle pointer 31 is inserted into the angle pointer limiting groove 9 on the angle scale 8, so that the angle pointer 31 can accurately indicate the angle scale, and the tail of the angle pointer 31 is fixed on the pointer mounting buckle 32 (such as Figure 9-1 As shown in FIG. 1 ), the pointer mounting buckle 32 is a circular ring, with an opening on one side away from the angle pointer 31 and extending outward to provide a buckle fixing hole 33 (as shown in FIG. 1 ). Figure 9-2As shown in FIG. 1 ), the inner diameter of the annular portion of the pointer mounting buckle 32 is based on the upper end of the fuel injector 11 (eg Figure 8 The pointer mounting buckle 32 can be locked after being installed on the fuel injector 11 fixed to the injection angle adjustment device through the buckle fixing hole 33).

[0036] (II) Fuel injection angle adjustment method for dual-fuel constant volume combustion bomb See also Fig.10 When conducting relevant experiments based on dual-fuel dual injection in the bomb cavity 1 of the dual-fuel constant-volume combustion bomb, it is required that the spray collision angle formed can be flexibly adjusted within the range of 30 to 100 degrees, and the dual-fuel spray combustion characteristics can be observed through four observation windows, wherein the spray collision angle is the sum of the fuel injection angles of the two fuel injectors 11, and the spacing between the injection angle adjustment devices where the two fuel injectors 11 are located can be pre-adjusted and fixed according to the actual bomb size and the fuel injector model.

[0037] When the dual-fuel constant volume combustion bomb is used for experiment, the fuel injection angle in the dual injection mode is generally adjusted by rotating the left and right fuel injectors 11 at the same angle. When the two fuel injectors 11 rotate at the same angle, the spray collision position of the fuel injected from both sides is located at the center of the bomb cavity 1. At the same time, when the rotation angle of the fuel injector 11 is reduced or the rotation angle of the fuel injector 11 is increased, the intersection of the spray collision moves downward or upward in the observation window. In order to facilitate the observation of the changes in the fuel injected from both sides after the collision, a minimum spray collision angle (specifically 30 degrees) is set. At this time, the fuel injection angle of the two fuel injectors 11 is 15 degrees, and the collision point is located near the center line of the observation window. After increasing the fuel injection angle (maximum 50 degrees), the intersection of the spray collision moves upward, and the dual-fuel spray formed after the collision will always be located in the field of view of the observation window and is in an observable state.

[0038] Experimental studies have shown that the rotation angles of the two fuel injectors 11 of the dual-fuel constant volume combustion bomb directly affect the mixing and combustion process of the injected fuels, and the optimal fuel injection angle for spray collision (i.e., the rotation angle of each fuel injector 11) is within the range of 20 to 35 degrees, as described below: (1) Within the range of 15 to 50 degrees, a fuel injection angle that is too small (less than 20 degrees) may result in a limited spray coverage of the fuel injector 11 (for example, this is usually the case when the injection pressure of the fuel injector 11 is high), uneven fuel mixing, and especially in the dual injection mode of liquid / gas fuel. An overly concentrated spray may also affect the full mixing of the ambient gas (for example, air) and the fuel injected into the bomb chamber 1, resulting in the inability to fully burn the fuel, thereby affecting the accurate evaluation of fuel utilization, combustion efficiency, and emissions (for example, the evaluation of combustion efficiency is too low). ; However, a fuel injection angle that is too large (more than 35 degrees) may cause the injected fuel to deviate from the central area of ​​the bomb chamber 1 (for example, this is usually the case when the injection pressure of the fuel injector 11 is high), resulting in the inability to fully burn the fuel, thereby affecting the accurate evaluation of fuel utilization, combustion efficiency, and emissions (for example, the evaluation of fuel utilization is too low, and the evaluation of emissions is too high); for the fuel injection angle within the range of 20 to 35 degrees, it can ensure that the fuel spray is fully diffused in the bomb chamber 1, and can maintain the concentration of the spray, so as to obtain accurate experimental results.

[0039] (2) By limiting the fuel injection angle to a range of 20 to 35 degrees, the repeatability of the experiment can be improved. For example, a fuel injection angle that is too large often introduces more uncertainties, resulting in greater fluctuations in the experimental results. Especially under the experimental conditions of high-pressure combustion bombs, the fuel injection angle will significantly affect the stability of the combustion process and the reliability of the measurement results.

[0040] (3) By limiting the fuel injection angle to a range of 20 to 35 degrees, the spray is prevented from impacting the wall of the bomb chamber, reducing equipment loss caused by high-temperature combustion, and enhancing the safety of the experiment. For example, an excessively large fuel injection angle causes the spray to approach the edge of the bomb chamber 1, increasing the risk of local high temperature and high pressure, thereby affecting the safety and life of the experimental equipment.

[0041] (4) The fuel injection angle adjustment range of 20 to 35 degrees can not only ensure that the spray of the fuel injector 11 is concentrated in the central area of ​​the bomb chamber 1, but also provide more fuel injection angle options, thereby promoting the progress of constant volume combustion bomb experiments and dual-fuel internal combustion engines.

Claims

1. A dual-fuel constant volume combustion bomb with adjustable injection angle, characterized in that: The invention comprises a projectile containing cavity (1), a projectile containing upper cover plate (4) and an injection angle adjustment device, wherein the injection angle adjustment device comprises a sleeve (10) arranged in a spherical table-shaped cavity between the top of the projectile containing cavity (1) and the projectile containing upper cover plate (4) and used for adjusting the fuel injection angle of the injector in the projectile containing cavity (1) by rotation, and the injector is fixed to the sleeve (10).

2. A dual-fuel constant volume combustion bomb with adjustable injection angle according to claim 1, characterized in that: Two hemispherical concave mounting grooves are arranged on the top of the bullet-containing cavity (1), and the concave mounting grooves penetrate the top of the bullet-containing cavity (1); two hemispherical concave mounting grooves are arranged on the bottom of the bullet-containing upper cover plate (4), and the concave mounting grooves penetrate the bullet-containing upper cover plate (4); sealing ring grooves are arranged on the circumference of the upper and lower concave mounting grooves, and the bushing (10) is in contact with the upper and lower concave mounting grooves located outside the bushing (10), and sealing rings are arranged in the corresponding sealing ring grooves on the upper and lower concave mounting grooves.

3. According to claim 1, a dual-fuel constant volume combustion bomb with adjustable injection angle, characterized in that: The bullet-containing upper cover plate (4) is fixed to the top of the bullet-containing cavity (1) by means of bolts.

4. According to claim 1, a dual-fuel constant volume combustion bomb with adjustable injection angle, characterized in that: The bullet-proof upper cover plate (4) is provided with a limit block (6) for limiting the rotation direction of the bushing (10) and the rotation angle in the rotation direction.

5. A dual-fuel constant volume combustion bomb with adjustable injection angle according to claim 1 or 2, characterized in that: The injection angle adjustment device further comprises an angle pointer (31), the injector being connected to the angle pointer (31); an angle scale (8) is provided on the upper cover plate (4) of the bomb container, the angle scale (8) being provided with an arc groove and a scale for indicating the rotation angle of the bushing (10), the angle pointer (31) being inserted into the arc groove on the angle scale (8); the fuel injection angle of the injector is adjusted between 15 and 50 degrees and indicated by the scale.

6. A method for adjusting the fuel injection angle of a dual-fuel constant volume combustion bomb, characterized in that: The following steps are involved: Two injectors are respectively installed in a bullet-containing cavity (1) via injection angle adjustment devices, each injection angle adjustment device comprising a bushing (10) arranged in a spherical table-shaped cavity between the top of the bullet-containing cavity (1) and an upper cover plate (4) of the bullet-containing cavity, and the two injectors are fixed to the corresponding bushing (10); the fuel injection angle of the injector fixed to the bushing is adjusted by rotating the bushing of the injection angle adjustment device, wherein the fuel injection angle of each injector is adjusted between 15 and 50 degrees.

7. The method for adjusting the fuel injection angle of a dual-fuel constant volume combustion bomb according to claim 6, characterized in that: The spray collision angle of the two injectors is between 30 and 100 degrees.

8. A method for adjusting the fuel injection angle of a dual-fuel constant volume combustion bomb according to claim 6 or 7, characterized in that: The fuel injection angles of the two injectors are both adjusted to 20 to 35 degrees.

9. The method for adjusting the fuel injection angle of a dual-fuel constant volume combustion bomb according to claim 7, characterized in that: The intersection point of the spray collision is located within the field of view of the observation window on the bullet-containing cavity (1).

10. The method for adjusting the fuel injection angle of a dual-fuel constant volume combustion bomb according to claim 6, characterized in that: The fuel injection angle is indicated by an angle pointer (31) connected to the injector and with the aid of an angle scale (8).

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