Liquid ammonia-hydrogen dual-fuel premixing direct injection combustion chamber

Abstract

The invention relates to the field of fuel injection systems of internal combustion engines, in particular to a liquid ammonia-hydrogen dual-fuel premixing direct injection combustion chamber which comprises a pre-combustion chamber, an injection end of the pre-combustion chamber is mounted in the combustion chamber, and a spark plug and a mixed fuel injection structure are mounted on the pre-combustion chamber. The inlet end of the mixed fuel injection structure is communicated with a liquid ammonia and hydrogen mixing structure, a hydrogen inlet is formed in the side wall of the liquid ammonia and hydrogen mixing structure, the inlet end of the liquid ammonia and hydrogen mixing structure is communicated with a liquid ammonia injection structure, an ammonia inlet is formed in the side wall of the liquid ammonia injection structure, and a valve structure is arranged in the liquid ammonia injection structure. The problems of fuel injection and ignition in the ammonia-hydrogen fusion engine are solved.

Description

Technical Field

[0001] The invention relates to the field of internal combustion engine fuel injection systems, and in particular to a liquid ammonia-hydrogen dual-fuel premixed direct injection combustion chamber. Background Art

[0002] As global attention to carbon emissions increases, achieving low-carbon emissions and clean energy transformation has become an important goal of social development. Ammonia and hydrogen, as potential new clean energy sources, are considered important carbon-free alternative fuels due to their renewable and zero-carbon emission characteristics. However, the combustion characteristics of liquid ammonia and hydrogen are significantly different from traditional fuels. For example, ammonia has a high ignition temperature, high ignition energy required, and slow flame propagation speed; although hydrogen requires low ignition energy, is flammable, and has a fast flame propagation speed, it has abnormal combustion (pre-ignition, detonation, flashback, etc.) in the application of internal combustion engines, so its application in combustion devices still faces many challenges. In order to solve the above problems, the development of an efficient and stable fuel injection and ignition system is the top priority of current research on ammonia-hydrogen fusion engines. Summary of the invention

[0003] The purpose of the present invention is to provide a liquid ammonia-hydrogen dual fuel premixed direct injection combustion chamber to solve the above problems. The present invention solves the problems of fuel injection and ignition in the ammonia-hydrogen fusion engine, and develops a liquid ammonia-hydrogen dual fuel premixed direct injection injector and precombustion chamber device to solve the needs of efficient, clean and stable combustion of ammonia-hydrogen engines under different working conditions. The precombustion chamber design adapted to the ammonia-hydrogen mixed fuel of the invention mainly overcomes the problems of low ammonia combustion speed and incomplete combustion, and assists the combustion of ammonia by utilizing the advantages of hydrogen diffusion speed and fast combustion flame propagation speed, low ignition energy, etc. At the same time, the invention can flexibly control the ammonia-hydrogen injection ratio, injection time, and the concentration of hydrogen in the precombustion chamber, realize flexible control of ammonia-hydrogen premixed combustion, and efficient combustion, and is expected to become one of the key technical directions for promoting the utilization of clean energy and the realization of low-carbon goals.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A liquid ammonia-hydrogen dual-fuel premixed direct injection combustion chamber comprises a precombustion chamber, an injection end of the precombustion chamber is installed in the combustion chamber, a spark plug and a mixed fuel injection structure are installed on the precombustion chamber, an inlet end of the mixed fuel injection structure is connected to a liquid ammonia hydrogen mixing structure, a side wall of the liquid ammonia hydrogen mixing structure is provided with a hydrogen inlet, an inlet end of the liquid ammonia hydrogen mixing structure is connected to a liquid ammonia injection structure, a side wall of the liquid ammonia injection structure is provided with an ammonia inlet, and a valve structure is provided in the liquid ammonia injection structure.

[0006] Preferably, the liquid ammonia injection structure includes an outer shell, an ammonia inlet is opened on the top side wall of the outer shell, a spring positioning pin is provided on the top of the outer shell, the spring positioning pin is a hollow structure, a spring is installed at the bottom end of the spring positioning pin, a needle valve is installed at the bottom end of the spring, a guide tube is provided on the outer sliding sleeve of the needle valve, the guide tube is installed at the center of the outer shell, a buffer spring is fixedly connected to the outer side of the needle valve, the bottom end of the buffer spring is installed on the buffer spring seat, the guide tube and the needle valve extend into the interior of the mixed fuel injection structure, an opening and closing structure for controlling the opening and closing of the needle valve is provided in the side wall of the outer shell, and the buffer spring seat is installed on the opening and closing structure.

[0007] Preferably, the opening and closing structure includes a yoke ring arranged on the outside of the outer shell, the yoke ring is threadedly connected to the top of the inner side of the yoke, a coil is provided under the yoke ring, and the coil is installed on the inner side of the yoke, the yoke, yoke ring and coil are all arranged on the outside of the outer shell, and an iron core is movably provided on the inner side of the outer shell, the iron core is movably sleeved on the outside of the buffer spring, needle valve and spring locating pin, and the inner bottom of the iron core is fixedly connected to the buffer spring seat.

[0008] Preferably, the liquid ammonia hydrogen mixing structure includes a mixing shell, a mixing chamber is opened in the center of the mixing shell, the hydrogen inlet is opened on the side wall of the mixing shell, the hydrogen inlet is communicated with the mixing chamber, the guide pipe and the needle valve extend into the mixing shell, a valve seat is installed at the top of the mixing chamber, a steel ball is installed in the valve seat, the steel ball is in contact with the bottom end of the needle valve, and the mixed fuel injection structure is installed at the bottom of the mixing shell.

[0009] Preferably, the pre-combustion chamber includes a cylindrical shell, the spark plug and the mixed fuel injection structure are installed on the cylindrical shell, the bottom of the cylindrical shell is connected to a conical shell, the bottom of the conical shell is connected to a small cylindrical shell, and the bottom of the small cylindrical shell is provided with a plurality of flame injection holes.

[0010] Preferably, the number of the flame injection holes is six and they are arranged at equal intervals, and the angle between the flame injection holes and the center line of the cylindrical shell is 60 degrees.

[0011] Preferably, the mixed fuel injection structure is the same as the liquid ammonia injection structure, and the outer shell of the mixed fuel injection structure is installed at the bottom end of the mixing shell of the liquid ammonia injection structure.

[0012] The present invention has the following technical effects:

[0013] 1. The present invention optimizes the structural coupling design of the injector and the pre-combustion chamber, so that it has a compact size and efficient combustion characteristics, while having the manufacturing advantages of high reliability and low cost.

[0014] 2. The pre-combustion chamber design provides a stable ignition and combustion environment, effectively improving the problem of ammonia combustion being difficult to ignite. The pre-combustion chamber can improve the ignition stability and flame propagation speed of the mixed fuel, thereby reducing ignition delay and achieving rapid response in the combustion process.

[0015] 3. The precise control of fuel injection and premixing technology is used to achieve uniform mixing of fuel and air in the precombustion chamber, which significantly improves the combustion efficiency and reduces the waste of unburned fuel, thereby improving the overall energy utilization efficiency.

[0016] The pre-combustion chamber designed by the present invention is an active pre-combustion chamber, which can flexibly adjust the concentration of hydrogen in the pre-combustion chamber according to the concentration of the mixed gas in different engine cylinders or the working conditions of the engine, and the active pre-combustion chamber can generate multiple high-temperature flame jets, provide multi-point ignition, and significantly improve the uniformity and stability of combustion, especially under lean combustion and high compression ratio conditions. Therefore, the pre-combustion chamber technology can optimize the mixing ratio of fuel and air and the preheating temperature in the combustion of ammonia-hydrogen mixed fuel, improve the ignition ability of the fuel, and through the precise injection and uniform mixing of the fuel, the pre-combustion chamber can significantly improve the combustion efficiency of the fuel and reduce the generation of incomplete combustion products, thereby achieving higher energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 The three-dimensional structure diagram of the ammonia-hydrogen dual fuel injector and pre-combustion chamber;

[0019] Figure 2 It is a schematic diagram of the cross-sectional structure of an ammonia-hydrogen dual fuel injector and a pre-combustion chamber;

[0020] Figure 3 This is a schematic diagram of the main structure of the pre-combustion chamber;

[0021] Figure 4 It is a schematic diagram of the structure of the pre-combustion chamber from a top view;

[0022] Figure 5 This is a schematic diagram of the main cross-sectional structure of the pre-combustion chamber.

[0023] Among them, 1. liquid ammonia injection structure; 101. ammonia inlet; 102. spring positioning pin; 103. yoke; 104. yoke ring; 105. spring; 106. coil; 107. iron core; 108. buffer spring; 109. buffer spring seat; 110. needle valve; 111. guide tube; 112. steel ball; 113. valve seat; 2. liquid ammonia hydrogen mixing structure; 201. hydrogen inlet; 202. mixing chamber; 3. mixed fuel injection structure; 4. spark plug; 5. pre-combustion chamber; 501. flame injection hole. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Reference Figures 1 to 5 As shown, this embodiment provides

[0027] A liquid ammonia-hydrogen dual-fuel premixed direct injection combustion chamber comprises a precombustion chamber 5, an injection end of the precombustion chamber 5 is installed in the combustion chamber, a spark plug 4 and a mixed fuel injection structure 3 are installed on the precombustion chamber 5, an inlet end of the mixed fuel injection structure 3 is connected to a liquid ammonia hydrogen mixing structure 2, a side wall of the liquid ammonia hydrogen mixing structure 2 is provided with a hydrogen inlet 201, an inlet end of the liquid ammonia hydrogen mixing structure 2 is connected to a liquid ammonia injection structure 1, a side wall of the liquid ammonia injection structure 1 is provided with an ammonia inlet 101, and a valve structure is provided in the liquid ammonia injection structure 1.

[0028] A further optimized solution is provided, wherein the liquid ammonia injection structure 1 comprises an outer shell, an ammonia inlet 101 is provided on the top side wall of the outer shell, a spring positioning pin 102 is provided on the top of the outer shell, the spring positioning pin 102 is a hollow structure, a spring 105 is installed on the bottom end of the spring positioning pin 102, a needle valve 110 is installed on the bottom end of the spring 105, a guide tube 111 is provided on the outer sliding sleeve of the needle valve 110, the guide tube 111 is installed at the center of the outer shell, a buffer spring 108 is fixedly connected to the outer side of the needle valve 110, the bottom end of the buffer spring 108 is installed on the buffer spring seat 109, the guide tube 111 and the needle valve 110 extend into the interior of the mixed fuel injection structure 3, an opening and closing structure for controlling the opening and closing of the needle valve 110 is provided in the side wall of the outer shell, and the buffer spring seat 109 is installed on the opening and closing structure.

[0029] A further optimized solution is provided, in which the opening and closing structure includes a yoke ring 104 arranged on the outside of the outer shell, the yoke ring 104 is threadedly connected to the top inner side of the yoke 103, a coil 106 is provided below the yoke ring 104, and the coil 106 is installed on the inner side of the yoke 103. The yoke 103, the yoke ring 104, and the coil 106 are all arranged on the outside of the outer shell, and an iron core 107 is movably provided on the inside of the outer shell, and the iron core 107 is movably mounted on the outside of the buffer spring 108, the needle valve 110, and the spring locating pin 102, and the inner bottom of the iron core 107 is fixedly connected to the buffer spring seat 109.

[0030] A further optimized solution is that the liquid ammonia hydrogen mixing structure 2 includes a mixing shell, a mixing chamber 202 is provided in the center of the mixing shell, a hydrogen inlet 201 is provided on the side wall of the mixing shell, the hydrogen inlet 201 is communicated with the mixing chamber 202, a guide pipe 111 and a needle valve 110 extend into the mixing shell, a valve seat 113 is installed at the top of the mixing chamber 202, a steel ball 112 is provided in the valve seat 113, the steel ball 112 is in contact with the bottom end of the needle valve 110, and the mixed fuel injection structure 3 is installed at the bottom of the mixing shell.

[0031] The steel ball 112 is generally used in a valve seat or sealing area to prevent oil leakage or maintain sealing under high pressure; and the needle valve 110 controls the flow and injection of fuel.

[0032] The steel ball 112 and the needle valve 110 are wrapped by the fuel. The steel ball 112 is set inside the valve seat 113. When there is no pressure, the steel ball 112 will press the valve seat 113 to ensure that the fuel will not leak. When the fuel pressure increases, the steel ball 112 will be pushed away to allow the fuel to flow. The position of the steel ball 112 is usually to ensure that when the needle valve 110 is opened, the fuel can be sprayed out smoothly while avoiding reverse flow or leakage.

[0033] According to a further optimization scheme, the pre-combustion chamber 5 includes a cylindrical shell, on which the spark plug 4 and the mixed fuel injection structure 3 are installed. The bottom of the cylindrical shell is connected to a conical shell, and the bottom of the conical shell is connected to a small cylindrical shell. A plurality of flame injection holes 501 are provided at the bottom of the small cylindrical shell.

[0034] According to a further optimization scheme, the number of the flame injection holes 501 is six and they are arranged at equal intervals, and the angle between the flame injection holes 501 and the center line of the cylindrical shell is 60 degrees.

[0035] According to a further optimization scheme, the mixed fuel injection structure 3 has the same structure as the liquid ammonia injection structure 1 , and the outer shell of the mixed fuel injection structure 3 is installed at the bottom end of the mixing shell of the liquid ammonia injection structure 1 .

[0036] Liquid ammonia fuel enters the liquid ammonia injection part 1 from the ammonia inlet 101, and is driven by an external pressure system to ensure stable fuel supply. After the liquid ammonia enters the guide tube 111, it flows into the mixed fuel injection part 3. The guide tube 111 provides a guide support for the needle valve 110 inside the injector to enable it to move smoothly along the axial direction. Hydrogen also enters the mixing chamber 202 from the hydrogen inlet 201 and mixes with the liquid ammonia fuel in proportion. When the coil 106 receives the injection signal, the coil 106 is energized to generate a magnetic field, which drives the iron core 107 to attract, so that the iron core 107 drives the needle valve 1 10 moves upward, opens the nozzle and sprays liquid ammonia into the mixing chamber 202. After the coil 106 is powered off, the spring 105 quickly resets and pushes the needle valve 110 to close the nozzle and cut off the fuel injection. The buffer spring 108 absorbs part of the kinetic energy during the needle valve 110 process to increase the service life of the system. The ammonia-hydrogen mixed fuel is fully mixed in the mixing chamber 202 to form a uniform mixed gas, which is then sprayed into the pre-combustion chamber 5 by the mixed fuel injection part 3. The spark plug 4 ignites the ammonia-hydrogen mixed fuel in the pre-combustion chamber 5, triggering initial combustion and providing a stable heat source for the main combustion chamber.

[0037] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" 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 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 should not be understood as a limitation on the present invention.

[0038] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A liquid ammonia-hydrogen dual fuel premixed direct injection combustion chamber, characterized in that: The invention comprises a pre-combustion chamber (5), wherein the injection end of the pre-combustion chamber (5) is installed in the combustion chamber, the pre-combustion chamber (5) is installed with a spark plug (4) and a mixed fuel injection structure (3), the inlet end of the mixed fuel injection structure (3) is connected with a liquid ammonia hydrogen mixing structure (2), the side wall of the liquid ammonia hydrogen mixing structure (2) is provided with a hydrogen inlet (201), the inlet end of the liquid ammonia hydrogen mixing structure (2) is connected with a liquid ammonia injection structure (1), the side wall of the liquid ammonia injection structure (1) is provided with an ammonia inlet (101), and a valve structure is provided in the liquid ammonia injection structure (1).

2. A liquid ammonia-hydrogen dual fuel premixed direct injection combustion chamber according to claim 1, characterized in that: The liquid ammonia injection structure (1) comprises a shell, wherein the top side wall of the shell is provided with an ammonia inlet (101), the top of the shell is provided with a spring positioning pin (102), the spring positioning pin (102) is a hollow structure, a spring (105) is installed at the bottom end of the spring positioning pin (102), a needle valve (110) is installed at the bottom end of the spring (105), a guide tube (111) is provided on the outer side of the needle valve (110), the guide tube (111) is installed at the center of the shell, a buffer spring (108) is fixedly connected to the outer side of the needle valve (110), the bottom end of the buffer spring (108) is installed on a buffer spring seat (109), the guide tube (111) and the needle valve (110) extend into the interior of the mixed fuel injection structure (3), an opening and closing structure for controlling the opening and closing of the needle valve (110) is provided in the side wall of the shell, and the buffer spring seat (109) is installed on the opening and closing structure.

3. A liquid ammonia-hydrogen dual fuel premixed direct injection combustion chamber according to claim 2, characterized in that: The opening and closing structure comprises a yoke ring (104) arranged on the outer side of the shell, the yoke ring (104) is threadedly connected to the top of the inner side of the yoke (103), a coil (106) is arranged below the yoke ring (104), and the coil (106) is installed on the inner side of the yoke (103), the yoke ring (104), and the coil (106) are all arranged on the outer side of the shell, and an iron core (107) is movably arranged on the inner side of the shell, and the iron core (107) is movably sleeved on the outer side of the buffer spring (108), the needle valve (110), and the spring positioning pin (102), and the inner bottom of the iron core (107) is fixedly connected to the buffer spring seat (109).

4. A liquid ammonia-hydrogen dual fuel premixed direct injection combustion chamber according to claim 2, characterized in that: The liquid ammonia hydrogen mixing structure (2) comprises a mixing shell, a mixing chamber (202) is provided at the center of the mixing shell, the hydrogen inlet (201) is provided on the side wall of the mixing shell, the hydrogen inlet (201) is communicated with the mixing chamber (202), the guide pipe (111) and the needle valve (110) extend into the mixing shell, a valve seat (113) is installed at the top end of the mixing chamber (202), a steel ball (112) is provided in the valve seat (113), the steel ball (112) is in contact with the bottom end of the needle valve (110), and the mixed fuel injection structure (3) is installed at the bottom of the mixing shell.

5. A liquid ammonia-hydrogen dual fuel premixed direct injection combustion chamber according to claim 4, characterized in that: The pre-combustion chamber (5) comprises a cylindrical shell, the spark plug (4) and the mixed fuel injection structure (3) are mounted on the cylindrical shell, the bottom of the cylindrical shell is connected to a conical shell, the bottom of the conical shell is connected to a small cylindrical shell, and the bottom of the small cylindrical shell is provided with a plurality of flame injection holes (501).

6. A liquid ammonia-hydrogen dual fuel premixed direct injection combustion chamber according to claim 5, characterized in that: The number of the flame injection holes (501) is six and they are arranged at equal intervals, and the angle between the flame injection holes (501) and the center line of the cylindrical shell is 60 degrees.

7. The liquid ammonia-hydrogen dual fuel premixed direct injection combustion chamber according to claim 4, characterized in that: The mixed fuel injection structure (3) has the same structure as the liquid ammonia injection structure (1), and the outer shell of the mixed fuel injection structure (3) is installed at the bottom end of the mixing shell of the liquid ammonia injection structure (1).

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