WO2023275630A1

WO2023275630A1 - Pulsed detonation device for internal combustion engine and method

Info

Publication number: WO2023275630A1
Application number: PCT/IB2022/054745
Authority: WO
Inventors: Moez BEN HOUIDI
Original assignee: King Abdullah University Of Science And Technology
Priority date: 2021-06-28
Filing date: 2022-05-20
Publication date: 2023-01-05

Abstract

A detonation system (200/300) includes an internal combustion engine (210/310) having a combustion chamber (218), and a detonation device (250) located outside the internal combustion engine (210/310), and having a detonation chamber (258) that is in fluid connection with the combustion chamber (218). The internal combustion engine (210/310) is configured to operate in a deflagration mode and the detonation device (250) is configured to operate in a detonation mode, but only deflagration waves enter the combustion chamber (218).

Description

PULSED DETONATION DEVICE FOR INTERNAL COMBUSTION

ENGINE AND METHOD

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/215,659, filed on June 28, 2021, entitled “PULSED DETONATION DEVICE FOR INTERNAL COMBUSTION ENGINE AND METHOD,” the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

TECHNICAL FIELD

[0002] Embodiments of the subject matter disclosed herein generally relate to an ignition system for an internal combustion engine, and more particularly, to an ignition system that includes a detonation device, which uses a detonation regime, to initiate and enhance the combustion of the fuel in the engine.

DISCUSSION OF THE BACKGROUND

[0003] Internal combustion engines have been widely used and commercialized in different fields, from transportation to electricity production.

Internal combustion engines are devices that utilize the combustion of a fuel and an oxidizer to convert the resulting heat into work. They can operate at different thermodynamic cycles depending on their design. Internal combustion engines can be classified into cyclic and continuous combustion configurations. Cyclic combustion engines include and are not limited to, reciprocating two-stroke and four- stroke piston and rotary engines. Continuous combustion engines include and are not limited to, gas turbine, ramjet, constant volume combustors, pulsed detonation, and rotating detonation engines. In the following, the term “engine” is used interchangeable with the term “internal combustion engine” or “combustion engine.” [0004] Internal combustion engines use different concepts to ignite the combustible charge and produce the heat. The ignition can be achieved by the usage of external energy sources such as sparks, also described as a plasma generated by a high voltage electrical field. A typical internal combustion engine having a spark as an ignitor is shown in Figure 1. The combustion engine 100 has a main volume 102 enclosed by a housing 104, and a piston 106. An intake valve 108 controls the amount of fuel and oxidizer that enters the main volume 102, and an exhaust valve 110 controls the timing of ejection of the burnt working gas from the main volume. After the fuel and oxidizer are provided in the main volume 102, a spark 112 initiates the combustion, locally, in a relatively small volume of the fuel- oxidizer charge 114 that is located right next to the head of the spark. This configuration is not efficient for a lean fuel-oxidizer mixture, which is defined as an excess of the oxidizer quantity as compared to the fuel. Using the lean-fuel oxidizer mixture is desirable in a combustion engine as less fuel is used, and also less pollution is generated. [0005] To improve the existing combustion engines, a pre-chamber igniter can be used. The pre-chamber igniter usually refers to a particular configuration where the combustion is started in a primary volume, outside the housing 104, and which is connected to the main volume 102 through orifices [1, 2] Such a concept, also referred to as a “turbulent jet ignition,” is believed to improve the combustion of the main charge and particularly to extend the lean limit operation of the internal combustion engine (ICE). Extending the lean limit operation would allow mitigate the pollutant emissions and leverage the system’s efficiency. For instance, in a reciprocating ICE, such an operation would allow to increase the compression ratio and thus improve the thermodynamic efficiency. Pre-chamber igniters are usually called active when the fuel and/or oxidizer are fed directly into the primary pre chamber volume and they are called passive otherwise. Many pre-chamber designs are in the art [3-9]

[0006] The ICE can be operated with different combustion propagation regimes, namely: deflagration, sequential auto-ignition, also called reaction fronts, detonation, and a combination of the aforementioned through transitional regimes. In most ICE applications, the detonation regime may occur accidentally and the traditional ICE’s housing would not withstand the pressure and temperature levels of this type of combustion. Thus, the operation of such engines is set to avoid such a regime. A detonation regime is denoting highly reactive combustion that involves high-pressure shock waves, which may be destructive and difficult to control. Several internal combustion engine concepts are specifically designed to operate with detonation flames. These can be classified into pulsed detonation [10-15] and continuous detonation engines [16,17] The detonation in such devices usually requires a higher wall/device-body temperature, compared to the operation in the other combustion regimes. This may lead to excessive stress of the structural elements materials (e.g. combustion chamber walls). For this reason, high-thermal stability materials are needed in detonation engines. However, the high wall temperature may be a route for increased heat transfer losses and thus, a decreased overall system’s efficiency. In most cases, pulsed and continuous detonation devices are used to produce thrust or work when combined with other subsystems such as turbines.

[0007] Thus, there is a need for a new engine that can take advantage of the detonation regime to extend the lean limit operation of the engine, without the need to increase the strength of the engine wall and/or reducing the overall system’s efficiency.

BRIEF SUMMARY OF THE INVENTION

[0008] According to an embodiment, there is a detonation system that includes an internal combustion engine having a combustion chamber, and a detonation device located outside the internal combustion engine, and having a detonation chamber that is in fluid connection with the combustion chamber. The internal combustion engine is configured to operate in a deflagration mode and the detonation device is configured to operate in a detonation mode, but only deflagration waves enter the combustion chamber.

[0009] According to another embodiment, there is a detonation device for initiating a deflagration in an internal combustion engine, and the detonation device includes an igniter, fuel and oxidizer valves for controlling an access of a fuel and an oxidizer into an internal detonation chamber, and an internal housing that defines the internal detonation chamber. The internal detonation chamber is configured to generate a deflagration flame, transition the deflagration flame to a detonation flame, propagate the detonation flame, quench the detonation flame to become another deflagration flame, and generate turbulent jets of gases based on the another deflagration flame.

[0010] According to yet another embodiment, there is a method for igniting a fuel inside an internal combustion engine. The method includes providing a fuel inside a detonation chamber of a detonation device, providing an oxidizer inside the detonation chamber, igniting with an igniter the fuel and the oxidizer, inside a first region of the detonation chamber, to generate a deflagration flame, accelerating the deflagration flame in a second region of the detonation chamber to generate a detonation flame, propagating the detonation flame within a third region to increase the temperature and pressure of gases present in the detonation chamber, quenching the detonation flame within a fourth region of the detonation chamber to generate another deflagration flame, generating turbulent jets of gases in a fifth region of the detonation chamber, based on the another deflagration flame, and discharging the turbulent jets of gases into a combustion chamber of an internal combustion engine to ignite a fuel inside the combustion chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0012] Figure 1 is a schematic diagram of an internal combustion engine that uses a spark plug to ignite the fuel;

[0013] Figure 2 is a schematic diagram of an internal combustion engine that uses a detonation device to ignite the fuel;

[0014] Figure 3 is a schematic diagram of another internal combustion engine that uses a detonation device to ignite the fuel;

[0015] Figures 4 and 5 are various views of the detonation device;

[0016] Figure 6 illustrates a combustion system that includes a reciprocating internal combustion engine having a detonation device;

[0017] Figure 7 illustrates a combustion system that includes a constant volume internal combustion engine having a detonation device; and [0018] Figure 8 is a flow chart of a method for igniting a fuel within an internal combustion engine with an external detonation device.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The following description of the embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to a pulsed detonation device that is used as a pre-chamber for an internal combustion engine. However, the embodiments to be discussed next are not limited to a pulsed detonation device or an internal combustion engine, but may be applied to other work generating systems.

[0020] Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0021] According to an embodiment, a novel pulsed detonation device or pre chamber, which is configured to work with an internal combustion engine, is configured to ignite a fuel mixture in a pre-chamber, outside of the main chamber of the engine. The pulsed detonation device is operated in a detonation regime so that the ignited fuel-oxidizer mixture generates turbulent jets of hot gases. These turbulent jets of hot gases are then injected into the main chamber of the engine to ignite the engine fuel-oxidizer mixture. However, before entering the main chamber of the engine, the detonation regime in the detonation device is damped to transition to a deflagration regime. Thus, the housing of the engine is protected from the shock waves of the detonation regime. In one application, the pulsed detonation device is configured to be added to any type of engine that uses combustion. However, for simplicity, the following embodiments refer to an internal combustion engine.

[0022] Figure 2 shows a combustion system 200 that includes an internal combustion engine 210 and an external pulsed detonation device 250. The term “external” is understood herein to mean that the detonation device 250 is located outside the housing 212 of the combustion engine 210, but in fluid communication with a main chamber 218 within such housing. The external pulsed detonation device 250 is located outside the housing 212 of the engine 210, but in contact with it. In this embodiment, the external pulsed detonation device 250 is provided on top of the combustion chamber 218 (also called herein “main chamber” or “main volume”), which is defined by a piston 214 and the housing 212. However, the external pulsed detonation device 250 may be placed at any location on the housing 212. The engine 210 may include one or more pistons 214 that are mechanically coupled to corresponding rods 216 (only one piston and corresponding rod is shown in the figure for simplicity). Any type of piston and rod may be used. Figure 2 also shows the engine 210 having an intake valve 220 that is configured to control access of a fuel-oxidizer mixture 222 into the combustion chamber 218. Any type of valve or device may be used for injecting the fuel and the oxidizer, either separately or pre mixed, into the main chamber. Such sub-system may be installed at any location that borders the combustion chamber 218, at any angle relative to a top surface of the piston 214. An exhaust valve 224 is also present for ejecting the burnt gases 226 (the burnt gas composition depends on the fuel used) that are in the combustion chamber 218 after the combustion in the main chamber. Similar to the intake valve 220, the exhaust valve 224 may be implemented by any known valve at any desired angle.

[0023] The external pulsed detonation device 250 has its own housing 252, which is placed on the housing 212 and is sized to withstand a detonation regime. In one embodiment, the housing 252 is machine as part of the housing 212, i.e. , the two housings may be made as an integral part. Note that the housing 212 of the engine 210 is not sized to withstand the detonation regime as the detonation device 250 is configured to not inject detonation flames into the main chamber 218. In other words, as discussed later in more details, the detonation device 250 uses a detonation regime, but the final jets are damped to a deflagration regime before being injected into the main chamber 214. One end of the detonation device 250 has a nozzle element 254, which is configured to enter inside the combustion chamber 218. An igniter 256, which is a spark plug in this embodiment, but any other known igniter may be used, is connected to the housing 252 so that at least a tip portion 256A of the igniter enters inside a detonation chamber 258 of the detonation device 250. The detonation device 250 may include, if it is an active combustor, a supply line 260 that provides fuel or a mixture of fuel and oxidizer 264, through a control valve 262, to the detonation chamber 258. The fuel or mixture of fuel and oxidizer

264 is then ignited by the igniter 256, so that a flame is initiated. As the detonation regime is intended to be limited inside to the detonation device 250, a deflagration to detonation transition module 266 is located inside the housing 252, for achieving this goal. Therefore, it is expected that the burning mixture experiences the detonation regime after being ignited by the ignitor 256, and transition back to the deflagration regime as it approaches the nozzle element 254. To help this transition, in one application, a detonation damper 268 may be provided upstream the nozzle element 254, inside the detonation chamber 258.

[0024] While Figure 2 shows the external pulsed detonation device 250 being connected to a conventional internal combustion reciprocating engine 210, in another embodiment, as shown in Figure 3, the detonation device 250 is used with a constant volume internal combustion engine 310 to form a combustion system 300. The detonation device 250 may have the same configuration as in Figure 2, or other configurations that achieve the detonation to deflagration functionality. Another configuration for the detonation device 250 is discussed later with regard to Figures 4 and 5. Returning to Figure 3, the constant volume internal combustion engine 310 includes a combustion chamber 218 defined by the housing 212. The fuel 223 is supplied to the combustion chamber 218 through one or more supply pipes 312, which are controlled by the fuel valve 225, and the oxidizer 227 is supplied to the combustion chamber 218 through one or more supply pipes 314, which are controlled by the oxidizer valve 229. A rotary valve 320 is provided at one side of the combustion chamber 218 for exhausting the burnt gases. An exhaust system 330 (for example, including a pipe) is provided next to the rotary valve 320, to discharge the burnt gases. Other subsystems can be mounted downstream of the exhaust nozzle to generate thrust or work.

[0025] The operation of the combustion systems 200 and 300 is similar and it is now discussed. The pulsed detonation device 250 is operated to generate turbulent jets 270 of hot gases that are used to ignite the fuel-oxidizer mixture 272 in the combustion chamber 218 of the internal combustion engine 210 or 310. Fuel and oxidizer are injected into the detonation chamber 258, also referred herein to as the “pre-chamber,” and into the combustion chamber 218, also referred herein to as the “main volume.” The combustion is started in the pre-chamber 258 using a suitable igniter 256 (e.g., spark plug, laser, pyrotechnic apparatus, etc.) or any ignition source that would induce the onset of a flame that propagates in this primary volume. The deflagration to detonation transition (DDT) device 266 is used to accelerate the flame propagation and induce the onset of detonation waves. The DDT device 266 could be, in one example, a set of obstacles, a Shchelkin spiral, or any other suitable DDT device. As the detonation combustion propagates in the pre-chamber 258, the pressure and temperature of the gas in this primary volume increase.

[0026] The detonation stage induces the hot gas to transfer from the primary volume 258 to the main volume 218 through the pre-chamber nozzle element 254 and the detonation damper 268. The pre-chamber nozzle element 254 and detonation damper 268 is a sub-system that damps the detonation flame and prevents its propagation to the main chamber 218. The pre-chamber nozzle element 254 can be a set of orifices, a flame arrester, a detonation damper, or any other device that quenches the detonation flame. As the hot burned gases 270 are ejected from the pre-chamber 258, they induce the ignition of the combustible fuel-oxidizer mixture 272 in the main chamber 218. The combustion in the pre-chamber 258 generates a high-pressure difference between the primary 258 and main 218 chambers, which contribute to generating the high turbulence jets 270 of hot gases in the combustion chamber 218. The turbulent jets 270 ignite and sustain the combustion in the main chamber 218, which leads to a faster combustion propagation compared to other configurations with more quiescent aerodynamics. [0027] Imposing a detonation combustion regime in the pre-chamber 258 has the advantage of creating a higher temperature and pressure in the pre-chamber compared to conventional engines that use a deflagration combustion regime. Using a detonation flame arrester 254 (e.g., a nozzle element) and 268 has the advantage of preventing the operation in the combustion chamber 218 with a detonation regime, which is characterized by severe shock waves that require the usage of expensive materials for the structural elements of the engine 210/310. The turbulent jets 270 generated by the pulsed detonation pre-chamber (PDP) device 250 induce a rapid combustion in the main chamber 218 while preventing from overheating the main chamber walls of the housing 212. Considering that the detonation regime is only operated in the detonation chamber 258, this would contribute to reducing the heat transfer losses as compared to the conventional pulsed detonation engines. The turbulent jet ignition would allow the ICE 210/320 to operate with lean and/or diluted fuel-oxidizer mixtures, which allows broader possibilities to optimize the ICE efficiency and pollutants emissions. [0028] The detonation device 250 may be fueled with hydrogen, ammonia or any other suitable reactive fuel. The dedicated fuel and/or oxidizer lines can be composed of injectors, check valves or any suitable device that would allow the injection of the needed amount of fuel and/or oxidizer into the pre-chamber. In one application, the internal combustion reciprocating engine 210 is operated conventionally and the detonation device 250 is actuated late during the compression stroke or early during the expansion stroke of the engine 210. For the engine 310, the fuel and oxidizer are introduced into the main volume 218 through supply lines which can be composed of fuel-oxidizer galleries, injectors, valves, or any suitable configuration that would allow supplying and premixing of the fuel and oxidizer. The detonation device 250 is actuated when the combustible mixture is introduced into the main chamber 218. Following the combustion in the main chamber 218, the burned gases are expanded and then exhausted by reintroducing fuel and oxidizer through the supply lines. The exhaust rotary valve 320 for the engine 310 can be used to pulse the combustion in the main chamber and to control the operation load. The expanded gases can be used to generate thrust or work by a combination with other suitable devices such as turbines.

[0029] A specific implementation of the PDP device 250 is now discussed with regard to Figures 4 and 5. It is noted that other implementations may be used based on the features now discussed. Figure 4 shows the PDP device 250 being equipped with an ignitor 256, e.g., a spark plug, a fuel supply valve 262, and an oxidizer valve 263, e.g., check valves. More or less valves may be used depending on the application. The valves 262 and 263 block the fuel and oxidizer flow from reverting upstream to the supply lines (not shown). In this embodiment, the volume of the detonation chamber 258 of the PDP device 250, called herein the primary volume, is smaller than 10% of the volume of the combustion chamber 218.

[0030] The PDP device 250 may be equipped with a cooling gallery 410 to control its wall temperature. More specifically, Figures 4 and 5 show the device 250 having an external housing 252 and an internal housing 452 (also called “primary volume” or “primary housing”), which is located within the external housing 252. The external and internal housings form an annulus, which is the cooling gallery 410. A cooling fluid (not shown) is pumped through inlet 412 into the cooling gallery 410 for cooling the internal housing 452. The hot fluid is then discharged through an outlet 414, outside the cooling gallery. The fluid may be cooled and then recirculated for a continuous cooling of the internal housing 452. In this way, the heat from the internal housing 452 is dissipated outside the PDP device 250. Note that because the PDP device 250 operates in the detonation regime, the heat generated inside is high. While the outside housing 252 has at least an inlet and an outlet, the internal housing 452 is sealed from the cooling fluid, so that the cooling fluid cannot enter inside the internal housing, i.e. , inside the detonation chamber 258.

[0031] The internal housing 452 extends along a longitudinal axis X of the detonation device 250, from one end 250A to the opposite end 250B, and defines the detonation chamber 258. The detonation chamber 258 includes plural regions that have different functionalities, e.g., fuel and oxidizer supply, fuel and oxidizer ignition, which results in deflagration flame generation, deflagration to detonation transition region, detonation propagation, detonation damping, and turbulent jet generation, and each of these regions is sized to achieve a corresponding functionality of these functionalities. In this embodiment, the detonation chamber 258 includes a pre-chamber region 454 that is shaped to have a cylindrical chamber 456 having a diameter A, as shown in Figure 5, which is fluidly connected to a convergent conical chamber 458, which converges into a cylindrical tunnel 460, which has a diameter B, smaller than the diameter A. The bore of the cylindrical tunnel 460 is restricted by one or more diameter restriction element 462, for example, six cylindrical obstacles that have an internal diameter C smaller than the internal diameter B of the tunnel 460. The cylindrical tunnel 460 with the one or more diameter restriction elements 462 form the second region of the detonation chamber 258.

[0032] The third region 464 of the detonation chamber 258 is a cylindrical chamber having a constant diameter B, and a length D that is larger than the diameter D. This region promotes the detonation propagation so that the temperature and pressure of the gasses present in this region are increased. Next, a fourth region 466 of the detonation chamber 258 is a detonation damper device, which in this embodiment is implemented as a divergent conical pipe 468 on the top and a perforated cylinder 470 at the bottom, as shown in Figures 4 and 5. The perforated cylinder 470 has a diameter E larger than the diameter B. The perforated cylinder 470 has plural channels 472 that extend along the longitudinal axis X. The perforated cylinder 470 has a length F that is longer than the diameter E. The plural channels 472 fluidly communicate with the last region 474 of the detonation chamber 258. This last region is called the section of the turbulent jet generation and terminates with the nozzle element 254, which has plural orifices 255. The nozzle element has a semi-spherical shape in this embodiment. Other shapes may be used. A diameter G of last region 474 of the detonation chamber 258 is equal to or larger than diameter E. All these relationships between the various elements of the detonation chamber 258 ensure that the detonation flame is generated and then quenched before entering the combustion chamber 218.

[0033] A flame that is generated at the igniter 256 inside the detonation chamber 258 is accelerated in the convergent conical chamber 458 to arrive at the detonation regime, and then propagates through all the parts discussed above until arriving at the fourth region 466 and the nozzle element 254, where it is slowed down to a deflagration wave, which is discharged into the combustion chamber 218. The operation of the detonation device 250 is now discussed with regard to Figures 4 and 5. The PDP device 250 may be operated cyclically. For this scenario, first, the fuel and oxidizer are injected into the cylindrical chamber 456, which allows to flush it with the combustible mixture and to exhaust residual burned gases from the previous cycle. The supply lines may be positioned in a cross opposite axis to generate a swirling flow when feeding the cylindrical chamber 456 with fuel and/or oxidizer. The igniter 256 is then used to ignite the combustible mixture in the first region 454 of the detonation chamber 258. As the combustion flame propagates with a deflagration regime in this first region 454, it accelerates when entering the convergent conical part 458. The accelerated flame is then propagating in the second region 460 of the detonation chamber 258 and is further accelerated as it passes through the set of diameter restrictions 462. This process is intended to make the flame transit from deflagration to a detonation regime. The detonation wave (or flame) propagates in the third region 464 of the detonation chamber 258 and thus further increases the pressure and the temperature of the gases in the internal housing. The detonation damper device 466 is used downstream to quench the detonation flame and to prevent the detonation wave from propagating to the main chamber 218. The quenched flame is ejected into the turbulent jet generator section 474, which is fluidly connected and protruding inside the main chamber 218. Turbulent jets 270 are generated in this section and they are injected into the main chamber 218. The plural channels 472 together with the divergent conical pipe 468 transition the detonation flame to a deflagration regime, before entering the main chamber 218. The higher pressure and temperature generated by the PDP device 250, as compared to the conventional pre-chambers, contribute to generating the turbulent jets 270 of higher intensity, which improves the reactivity of the combustible mixture in the main chamber 218. In one application, the various sizes A to G are selected so that A > 2 x B, C = ½ x B, D > 3 x B, F > E, and G ³ E. These values ensure that the detonation flame is quenched and the turbulent jets 270 entering the combustion chamber 218 do not generate detonation waves, but they are characterized by high pressure and temperature. Many variations of this implementation of the detonation device 250 may be envisioned as long as the device includes a region to initiate the deflagration flame, a region to accelerate the flame to become a detonation flame, a region to quench the detonation flame to transform it into turbulent jets, and a region to inject the turbulent jets into the combustion chamber of an internal combustion engine. [0034] In this regard, Figure 6 shows a detonation system 600 having the detonation device 250 connected to the internal combustion engine 210 so that the nozzle element 254 is located inside the combustion chamber 218 while Figure 7 shows a detonation system 700 that uses the same detonation device 250 connected to the constant volume internal combustion engine 310 with the nozzle element 254 being located inside the combustion chamber 218. The combustion chamber 218 is shown having an exhaust outlet 322 for the engine 310. As previously noted, the detonation device 250 is an active one, i.e. , its fuel and oxidizer are supplied independent of the fuel and oxidizer of the engine 210/310. In fact, the fuel and/or oxidizer used by the detonation device 250 may be different from those of the engine (e.g., hydrogen versus gasoline, respectively.) However, the detonation device 250 may be modified to be passive, i.e., to get the fuel and oxidizer from the engine 210/310 as long as the detonation device 250 has the deflagration region, the detonation region, the quenching region and the turbulent jet formation region. The engine can be any of a light-duty, heavy-duty, large-bore marine reciprocating piston-engine, gas turbines, jet engines, etc.

[0035] A method for igniting a fuel inside the internal combustion engine 210/310 is now discussed with regard to Figure 8. The method includes a step 800 of providing a fuel inside a detonation chamber of a detonation device, a step 802 of providing an oxidizer inside the detonation chamber, a step 804 of igniting with an igniter the fuel and the oxidizer, inside a first region of the detonation chamber, to generate a deflagration flame, a step 806 of accelerating the deflagration flame in a second region of the detonation chamber to generate a detonation flame, a step 808 of propagating the detonation flame within a third region to increase the temperature and pressure of gases present in the detonation chamber, a step 810 of quenching the detonation flame within a fourth region of the detonation chamber to generate another deflagration flame, a step 812 of generating turbulent jets of gases in a fifth region of the detonation chamber, based on the another deflagration flame, and a step 814 of discharging the turbulent jets of gases into a combustion chamber of an internal combustion engine to ignite a fuel inside the combustion chamber.

[0036] The disclosed embodiments provide a detonation device that generates turbulent jets of gases that are injected into an internal combustion engine for combusting the fuel. It should be understood that this description is not intended to limit the invention. On the contrary, the embodiments are intended to cover alternatives, modifications and equivalents, which are included in the spirit and scope of the invention as defined by the appended claims. Further, in the detailed description of the embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the claimed invention. However, one skilled in the art would understand that various embodiments may be practiced without such specific details.

[0037] Although the features and elements of the present embodiments are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements disclosed herein. [0038] This written description uses examples of the subject matter disclosed to enable any person skilled in the art to practice the same, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims.

References

The entire content of all the publications listed herein is incorporated by reference in this patent application.

[1] Alvarez, Carlos Eduardo Castilla, Giselle Elias Couto, Vinicius Ruckert Roso, Arthur Braga Thiriet, and Ramon Molina Valle. "A review of prechamber ignition systems as lean combustion technology for SI engines." Applied Thermal Engineering 128 (2018): 107-120;

[2] Biswas, Sayan. Physics of turbulent jet ignition: mechanisms and dynamics of ultra lean combustion. Springer, 2018;

[3] U.S. Patent No. 9,316,144 B2;

[4] U.S. Patent No. 9,353,674 B2;

[5] U.S. Patent No. 8,857,405 B2;

[6] U.S. Patent No. 9,797,296 B2;

[7] U.S. Patent No. 5,024,193 A;

[8] German Patent DE 102018212 917 A1;

[9] U.S. Patent No. 9,217,360 B2;

[10] U.S. Patent No. 7,958,732 B2;

[11] U.S. Patent No. 7,278,611 B2; [12] U.S. Patent No. 7,340,903 B2;

[13] Russian Patent No. RU2331784C2;

[14] U.S. Patent No. 8,683,780 B2;

[15] U.S. Patent No. 6,978,616 B1;

[16] U.S. Patent Application Publication No. 2020/0063967 A1; and

[17] International Publication No. WO 2012/142485 A2.

Claims

WHAT IS CLAIMED IS:

1. A combustion system (200/300) comprising: an internal combustion engine (210/310) having a combustion chamber (218); and a detonation device (250) located outside the internal combustion engine (210/310), and having a detonation chamber (258) that is in fluid connection with the combustion chamber (218), wherein the internal combustion engine (210/310) is configured to operate in a deflagration mode and the detonation device (250) is configured to operate in a detonation mode, but only deflagration waves enter the combustion chamber (218).

2. The combustion system of Claim 1 , wherein the detonation chamber (258) of the detonation device comprises: an igniter (256); a first region (454) in which the igniter (256) generates an initial deflagration flame; a second region (460) configured to transition the deflagration flame to a detonation flame by using one or more diameter restriction elements (462); a third region (464) configured to propagate the detonation flame; a fourth region (466) configured to quench the detonation flame into another deflagration flame; a fifth region (474) configured to generate turbulent jets (270) of gas based on the another deflagration flame; and a nozzle element (254) configured to discharge the turbulent jets of gas directly into the combustion chamber.

3. The combustion system of Claim 2, wherein the nozzle element is located inside the combustion chamber.

4. The combustion system of Claim 2, wherein the first region includes a cylindrical chamber fluidly connected to a convergent conical chamber, to accelerate the deflagration flame.

5. The combustion system of Claim 4, wherein an internal diameter of the cylindrical chamber is at least twice as large as an internal diameter of the second region.

6. The combustion system of Claim 2, wherein the one or more diameter restriction elements of the second region have an internal diameter smaller than an internal diameter of the second region to further accelerate the deflagration flame.

7. The combustion system of Claim 6, wherein an internal diameter of the one or more diameter restriction elements is half an internal diameter of the second region.

8. The combustion system of Claim 2, wherein a length of the third region is at least three times an internal diameter of the second region.

9. The combustion system of Claim 2, wherein the fourth region includes a divergent conical pipe fluidly connected to a perforated cylinder having plural channels.

10. The combustion system of Claim 9, wherein a length of the plural channels is larger than a diameter of the perforated cylinder.

11. The combustion system of Claim 2, wherein the nozzle element has plural orifices and a diameter equal to or larger than a diameter of a perforated cylinder which is part of the fourth region.

12. A detonation device (250) for initiating a deflagration in an internal combustion engine (210/310), the detonation device (250) comprising: an igniter (256); fuel and oxidizer valves (262, 263) for controlling an access of a fuel and an oxidizer into an internal detonation chamber (258); and an internal housing (452) that defines the internal detonation chamber (258), wherein the internal detonation chamber (258) is configured to generate a deflagration flame, transition the deflagration flame to a detonation flame, propagate the detonation flame, quench the detonation flame to become another deflagration flame, and generate turbulent jets (270) of gases based on the another deflagration flame.

13. The detonation device of Claim 12, wherein the internal detonation housing comprises: a first region (454) in which the igniter (256) generates an initial deflagration flame; a second region (460) configured to transition the deflagration flame to the detonation flame by using one or more diameter restriction elements (462); a third region (464) configured to promote the detonation flame; a fourth region (466) configured to quench the detonation flame into the another deflagration flame; a fifth region (474) configured to generate the turbulent jets (270) of gas; and a nozzle element (254) configured to discharge the turbulent jets of gas directly into a combustion chamber of an internal combustion engine.

14. The detonation device of Claim 13, wherein the first region includes a cylindrical chamber fluidly connected to a convergent conical chamber, to accelerate the deflagration flame and wherein an internal diameter of the cylindrical chamber is at least twice as large as an internal diameter of the second region.

15. The detonation device of Claim 13, wherein the one or more diameter restriction elements of the second region has an internal diameter smaller than an internal diameter of the second region to further accelerate the deflagration flame and the internal diameter of the one or more diameter restriction elements is half an internal diameter of the second region.

16. The detonation device of Claim 13, wherein a length of the third region is at least three times an internal diameter of the second region.

17. The detonation device of Claim 13, wherein the fourth region includes a divergent conical pipe fluidly connected to a perforated cylinder having plural channels.

18. The detonation device of Claim 17, wherein a length of the plural channels is larger than a diameter of the perforated cylinder.

19. The detonation device of Claim 13, wherein the nozzle element has plural orifices and a diameter equal to or larger than a diameter of a perforated cylinder which is part of the fourth region.

20. A method for igniting a fuel inside an internal combustion engine (210/310), the method comprising: providing (800) a fuel inside a detonation chamber (258) of a detonation device (250); providing (802) an oxidizer inside the detonation chamber (258); igniting (804) with an igniter (256) the fuel and the oxidizer, inside a first region (454) of the detonation chamber (258), to generate a deflagration flame; accelerating (806) the deflagration flame in a second region (460) of the detonation chamber (258) to generate a detonation flame; propagating (808) the detonation flame within a third region (464) to increase the temperature and pressure of gases present in the detonation chamber (258); quenching (810) the detonation flame within a fourth region (472) of the detonation chamber (258) to generate another deflagration flame; generating (812) turbulent jets (270) of gases in a fifth region (474) of the detonation chamber (258), based on the another deflagration flame; and discharging (814) the turbulent jets of gases into a combustion chamber (218) of an internal combustion engine to ignite a fuel inside the combustion chamber (218).