Turbulent jet controlled compression ignition (TJCCI) engine

Abstract

A method of operation of an engine includes operating the engine in first and second engine operation mapping regions 306 and 308 by performing passive jet ignition combustion with a first volume of residual gas and a first stoichiometric fuel mixture. Operating the engine in a third engine operation map region 310 by performing turbulent jet controlled compression ignition (TJCCI) with the cooled first volume of exhaust gas recirculation and the ultra-lean fuel mixture; operating the engine in a fourth engine operation mapping region 312 by performing passive jet ignition combustion with the cooled exhaust gas recirculated second volume and a third stoichiometric fuel mixture; the engine is operated in a fifth engine operation mapping region 314, characterized in that the engine is turned off. The engine is operated in a mode transition region between second, third and fourth engine operation mapping regions 308, 310 and 312 by performing passive jet ignition combustion with a second volume of residual gas and a second stoichiometric fuel mixture.

Description

Background Art

[0001] Internal combustion engines typically operate by burning a fuel mixture in a main combustion chamber, where the combustion can drive the movement of one or more components in the engine. A typical internal combustion engine can include a plurality of cylinders that define the main chamber within the engine block, where combustion within the cylinder causes an internal piston to move, and the internal piston can in turn cause the engine's crankshaft to move. The fuel mixture can enter the main chamber through an inlet and burn.

[0002] Combustion within the main chamber of an internal combustion engine can be generated using different mechanisms, such as using high pressure and high temperature conditions or using an ignition device. A common ignition device provided creates a continuous ignition source or spark such that the air and fuel mixture within the main chamber of the engine is combusted by the spark. Conventionally, the spark is created by energizing a copper ignition rod and placing the energized ignition rod within a set distance of a grounded nickel or iridium plate, where a continuous spark is created by the electrical difference between the energized ignition rod and the grounded plate. Alternatively, a portion of the air and fuel mixture can be ignited in a pre-main chamber, where the air and fuel mixture is ignited and the resulting combustion reaction is released into the main chamber to ignite the remainder of the air and fuel mixture. After combustion within the main chamber, the combustion products can be exhausted as an exhaust gas through an outlet of the main chamber.

[0003] After combustion within the main chamber, the combustion products can be exhausted as an exhaust gas through an outlet of the main chamber. Some internal combustion engines use exhaust gas recirculation (EGR) technology, which recirculates a portion of the engine's exhaust gas back into the main chamber for the air and fuel mixture. By recirculating the exhaust gas back into the main chamber of the internal combustion engine, the EGR system can be used to dilute the amount of oxygen present during combustion, thereby reducing the combustion temperature within the main chamber and reducing nitrogen oxide (NO x ) emissions from the engine.

[0004] Combustion and valve timing and control within the engine are typically electronically controlled by a computer system. The computer system can implement a predetermined operating schedule to allow the fuel and air mixture to enter the main chamber, combust the mixture, and exhaust the gas. Summary of the Invention

[0005] This Summary of the Invention is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary of the Invention is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0006] In one aspect, embodiments disclosed herein relate to a method of operating an engine, the method may include: operating the engine in a first engine operating map region and a second engine operating map region by performing passive jet ignition combustion with a first volume of residual gas and a first stoichiometric fuel mixture; operating the engine in a third engine operating map region by performing turbulence jet controlled compression ignition (TJCCI) with a first volume of cooled exhaust gas recirculation and an ultra-lean fuel mixture; operating the engine in a fourth engine operating map region by performing passive jet ignition combustion with a second volume of cooled exhaust gas recirculation and a third stoichiometric fuel mixture; and operating the engine in a fifth engine operating map region, wherein the fifth engine operating map region is characterized by the engine being shut off. The engine may also operate in a mode transition region between the second, third, and fourth engine operating map regions by performing passive jet ignition combustion with a second volume of residual gas and a second stoichiometric fuel mixture, wherein the second volume of residual gas is controlled by ignition timing to meet a target engine load. One cycle of the engine may span two reciprocations of a piston within the engine, wherein the cycle includes an exhaust stroke, an intake stroke, a compression stroke, and an expansion stroke, a gas exchange top dead center piston position located between the exhaust stroke and the intake stroke, an ignition top dead center piston position located between the compression stroke and the expansion stroke, and a bottom dead center piston position located between the intake stroke and the compression stroke and between the expansion stroke and the exhaust stroke.

[0007] In another aspect, embodiments disclosed herein relate to a turbulent jet controlled compression ignition (TJCCI) engine system. The TJCCI engine system can include: an engine having an engine block with cylinders; a piston configured to move up and down inside a main chamber of a cylinder; a pre-chamber in fluid communication with the main chamber; and a fuel injector mounted to the engine block and in fluid communication with the main chamber. The TJCCI engine system can further include a computer system having a memory and a processor, in communication with the piston, an exhaust valve, an intake valve, a spark plug, and one or more fuel injectors. The computer processor is configured to: operate the engine in a first engine operating map region and a second engine operating map region by performing passive jet ignition combustion with a first volume of residual gas and a first stoichiometric fuel mixture; operate the engine in a mode transition region by performing passive jet ignition combustion with a second volume of residual gas and a second stoichiometric fuel mixture, wherein the second volume of residual gas is controlled by ignition timing to meet a target engine load; operate the engine in a third engine operating map region by performing turbulent jet controlled compression ignition (TJCCI) with a first volume of cooled exhaust gas recirculation and an ultra-lean fuel mixture; operate the engine in the mode transition region; operate the engine in a fourth engine operating map region by performing passive jet ignition combustion with a second volume of cooled exhaust gas recirculation and a third stoichiometric fuel mixture; and operate the engine in a fifth engine operating map region, wherein the fifth engine operating map region is characterized by the engine being turned off.

[0008] In yet another aspect, embodiments disclosed herein relate to a method that includes designing an engine to operate using passive jet ignition combustion at a first set of engine parameters. Passive jet ignition combustion can include: injecting fuel from a fuel injector into a main chamber of the engine such that an amount of the fuel is directed into a prechamber to provide a prechamber fuel-air mixture in the prechamber and a main chamber fuel-air mixture in the main chamber; generating a spark in the prechamber to ignite the prechamber fuel-air mixture; and injecting the ignited prechamber fuel-air mixture from the prechamber into the main chamber to ignite the main chamber fuel-air mixture. The first set of engine parameters can include an engine speed ranging from a first minimum speed to a first maximum speed, and an engine load ranging from a first minimum load to a first maximum load, wherein at the first set of engine parameters, the fuel-to-air ratio provided in the main chamber and the prechamber after injection is stoichiometric. The method can further include designing the engine to operate using passive jet ignition combustion at a second set of engine parameters, the second set of engine parameters including an engine speed ranging from greater than the first maximum speed to a second maximum speed, and an engine load ranging from the first minimum load to a second maximum load. The method can further include designing the engine to change the fuel-to-air ratio provided in the main chamber and the prechamber to an ultra-lean ratio (more air than fuel) when the engine is operating at a third set of engine parameters, wherein at the third set of engine parameters, the engine speed is greater than the first maximum speed and the engine load is greater than the second maximum load.

[0009] Other aspects and advantages of the claimed subject matter will become more apparent from the following description and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Specific embodiments of the disclosed technology will now be described in detail with reference to the accompanying drawings. For consistency, like elements in the various figures are designated by like reference numerals. The dimensions and relative positions of the elements in the figures are not necessarily drawn to scale. For example, the shapes and angles of the various elements are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve the readability of the drawings. Further, the particular shapes of the elements as illustrated are not necessarily intended to convey any information regarding the actual shape of the particular elements, but are merely selected for ease of identification in the drawings.

[0011] Figure 1 A combustion system is shown in accordance with one or more embodiments.

[0012] Figure 2 An apparent heat release rate profile is shown in accordance with one or more embodiments.

[0013] Figure 3 An engine operating map is shown in accordance with one or more embodiments.

[0014] Figure 4 Shows an engine timing diagram according to one or more embodiments.

[0015] Figure 5 Shows an engine timing diagram according to one or more embodiments.

[0016] Figure 6 Shows an engine timing diagram according to one or more embodiments.

[0017] Figure 7 Shows an engine timing diagram according to one or more embodiments.

[0018] Figure 8 Shows a computer system according to one or more embodiments.

[0019] Figure 9 Shows a flowchart according to one or more embodiments.

[0020] Figure 10 Shows a flowchart according to one or more embodiments. Detailed Description

[0021] In the following detailed description of embodiments of the present disclosure, many specific details are set forth to provide a more thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0022] Throughout this application, ordinal numbers (such as first, second, third, etc.) may be used as adjectives for elements (i.e., any nouns in this application). The use of ordinal numbers does not imply or create any particular ordering of the elements, nor does it limit any element to a single element unless explicitly disclosed, such as by using terms like "before," "after," "single," and other such terms. Instead, the use of ordinal numbers is for distinguishing between elements. By way of example, a first element is distinct from a second element, and the first element may contain more than one element and may follow (or precede) the second element in the ordering of the elements.

[0023] In Figures 1 - 10In the following description, in various embodiments disclosed herein, any component described with respect to a figure may be equivalent to one or more similarly named components described with respect to any other figure. For the sake of brevity, the description of these components may not be repeated in each figure. Thus, each embodiment of the components of each figure may be incorporated by reference and is assumed to optionally exist within each other figure having one or more similarly named components. Additionally, according to various embodiments disclosed herein, any description of the components of a figure will be interpreted as an optional embodiment, which may be implemented in addition to, in combination with, or in place of the embodiments described for the corresponding similarly named components in any other figure.

[0024] In one aspect, embodiments disclosed herein relate to methods and systems for performing turbulent jet compression ignition (TJCCI) to control a turbulent jet to improve engine efficiency and reduce nitrogen oxide emissions. In another aspect, embodiments disclosed herein relate to methods for passively fueling a pre-chamber and performing different combustion strategies related to a designed engine operating map. In yet another aspect, embodiments disclosed herein relate to methods for designing an engine to operate in multiple engine operating regions depending on engine speed and engine load.

[0025] Reference Figure 1 , which illustrates a combustion system 100 according to embodiments disclosed herein. The combustion system 100 may be an internal combustion engine including at least one cylinder 101 formed within an engine block or engine body 102. In Figure 1 , only a portion of the engine block is shown, and only one cylinder within the engine block is shown, although the engine block may have a plurality of cylinders. The cylinder 101 may include a main chamber 103. The main chamber 103 may be the combustion chamber of the combustion system 100. Additionally, a cylinder head 104 may be mounted on top of the cylinder 101 and form the upper end of the main chamber 103. A piston 105 may be disposed within the cylinder 101 and form the lower end of the main chamber 103. During an engine cycle, the piston 105 moves up and down within the cylinder 101, and the volume of the main chamber 103 changes with the position of the piston 105. Further, the piston 105 may be connected to a crankshaft (not shown) by a connecting rod. The crankshaft may convert the reciprocating motion of the piston 105 into a rotational motion, as is well known in the art.

[0026] A pre-chamber 117 may be positioned in fluid communication with the main chamber 103. According to one or more embodiments, the pre-chamber 117 may have a much smaller volume than the main chamber 103. For example, in one or more embodiments, the pre-chamber 117 may have a volume between 0.5 cubic centimeters and 3 cubic centimeters, while the main chamber 103 may have a displacement volume greater than 300 cubic centimeters.

[0027] The pre - combustion chamber 117 may have one or more nozzles integrally formed through the wall of the pre - combustion chamber 117 such that the one or more nozzles provide fluid communication between the pre - combustion chamber 117 and the main chamber 103. In some embodiments, the nozzle may be formed by a nozzle insert that extends through the pre - combustion chamber wall to provide fluid communication between the pre - combustion chamber 117 and the main chamber 103. The one or more nozzles are configured to accelerate the fuel due to piston compression during the compression stroke when fuel enters the pre - combustion chamber 117 from the main chamber 103, which can enhance the vaporization and mixing of the fuel. The spark plug 118 may be connected to the pre - combustion chamber 117 and configured to interface with the pre - combustion chamber 117. The spark plug 118 may be used to ignite the fuel within the pre - combustion chamber 117 before some or all of the combustion mixture may jet through the one or more nozzles and into the main chamber 103.

[0028] A fuel injector 107 according to an embodiment of the present disclosure may be installed in the cylinder head 104. A fixture (not shown) may removably secure the fuel injector 107 to the cylinder head 104. The fixture may be disposed on top of the fuel injector 107 and may be attached to the cylinder head 104 to hold the position of the fuel injector 107. The fuel injector 107 may be aligned, coaxial, or angled with respect to the cylinder axis of the cylinder head 104. In one example, the installation of the fuel injector 107 to the cylinder head 104 includes forming one or more spray nozzle assemblies. In some embodiments, the nozzle assembly may include a fuel passage, a pre - mixing tube, and ports formed inside the tip of the fuel injector 107. The fuel injector 107 may be in fluid communication with the main chamber 103 such that the one or more spray nozzle assemblies may be in a position where the orifices of the spray nozzle assemblies are in fluid communication with the main chamber 103.

[0029] In one or more embodiments, one or more of the spray nozzle assemblies may have a wide spray angle. A first spray nozzle assembly of the one or more spray nozzle assemblies may be oriented to face and be aligned with one of the nozzles in the pre - combustion chamber 117. This first spray nozzle assembly may be configured to passively supply fuel to the pre - combustion chamber 117 while actively supplying fuel to the main chamber 103.

[0030] Still referring to Figure 1, the cylinder head 104 may optionally include a second fuel injector 108 for use in combination with the fuel injector 107. As shown, the cylinder head 104 may include at least one intake passage 119 that terminates in a second intake port 110. The second fuel injector 108 may be positioned along the intake passage 119 in a configuration that allows fuel to be injected into the intake passage 119. The second fuel injector 108 may be a fuel injector similar to the fuel injector 107. Additionally, the intake port 110 may include an intake valve 113 to control the opening and closing of the intake port 110. When the second fuel injector 108 injects fuel, air flowing through the intake passage 119 to the main chamber 103 may be entrained in the fuel spray plume of the second fuel injector 108. Although not shown, the main chamber 103 and the intake passage 119 may be connected to an air source in a conventional manner. The air in the main chamber 103 and the intake passage 119 may be ambient air or a mixture of ambient air and recirculated exhaust gas.

[0031] The cylinder head 104 may further include at least one exhaust passage 111 having an exhaust port 112. An exhaust valve 114 may be arranged to control the opening and closing of the exhaust port 112. When the exhaust port 112 is open, exhaust gas may be pushed out of the main chamber 103 into the exhaust passage 111. The intake passage 119, the exhaust passage 111, and the associated components (such as valves 113, 114 and fuel injectors 107, 108) may be provided in the cylinder head 104 of each cylinder in the combustion system 100, such as Figure 1 the arrangement shown for cylinder 101.

[0032] In one or more embodiments, the fuel injectors 107, 108 may be used to directly inject fuel into the main chamber 103 and / or the intake passage 119. The fuel injectors 107, 108 may be fluidly connected to a fuel line 115 that communicates with a fuel supply 116.

[0033] In one or more embodiments, the computer 120 may include a control system, such as an engine control unit, that may control the opening and closing of the fuel injectors 107, 108 to deliver fuel to the main chamber 103 at a desired time during an engine cycle. The control system may also control the opening and closing of the intake and exhaust valves 113, 114. In one or more embodiments, the computer 120 may include a processor and a user interface panel where a user may provide inputs to the computer 120, such as commands.

[0034] In some embodiments, a cable (not shown) may be coupled to fuel injectors 107, 108, such as an electrical or hydraulic power cable. The cable may supply power to fuel injectors 107, 108 from a power source (not shown). Additionally, the cable may be connected to computer 120 to control fuel injectors 107, 108. Computer 120 may include instructions or commands to automatically operate fuel injectors 107, 108, or a user may manually control computer 120 at a user interface panel (not shown). Further, computer 120 may be connected to an office via satellite such that a user may remotely monitor the situation and send commands to fuel injectors 107, 108. If a leak and performance issue are detected, an alarm may be sent to the control system to manually or automatically adjust or shut off fuel injectors 107, 108.

[0035] In one or more embodiments, combustion system 100 may be used to perform turbulent jet controlled compression ignition (TJCCI). TJCCI may involve passively fueling pre - combustion chamber 117 and igniting the fuel within pre - combustion chamber 117. In one or more embodiments, as discussed above, pre - combustion chamber 117 may be passively fueled by the precise alignment of one of the spray nozzle assemblies in the spray nozzle assembly of a fuel injector with a pre - combustion chamber nozzle. In other embodiments, pre - combustion chamber 117 may be passively fueled by a rebounding fuel jet that may initially be generated by fuel injector 107 and may rebound from piston 105 or other main chamber inner surface to enter pre - combustion chamber 117 through one or more nozzles. TJCCI may also be performed using a third fuel injector (not shown) disposed within pre - combustion chamber 117 for active fueling of the pre - combustion chamber. According to embodiments of the present disclosure, TJCCI may be characterized by: jetting a turbulent mixture into main chamber 103, causing the temperature and pressure of the air - fuel mixture to increase for compression ignition (or auto - ignition); and a related engine operating map, which will be Figures 4 - 7 discussed. Further, TJCCI may also be characterized by a specific timing diagram, embodiments of which will also be Figures 4 - 7 discussed. Accordingly, pre - combustion chamber 117 may be actively or passively fueled in any manner or configuration without departing from the scope of the present disclosure. Similarly, TJCCI may be performed in combination with any pre - combustion chamber fueling strategy according to the methods described herein without departing from the scope of the present disclosure.

[0036] Now turning to Figure 2 , Figure 2Shows an apparent heat release rate spectrum 200 and a corresponding spark timing spectrum 210 from a spark plug according to one or more embodiments. In one or more embodiments, the apparent heat release rate spectrum 200 can be represented as the engine crank angle on the horizontal axis 202 and the apparent heat release rate on the vertical axis 204. The apparent heat release rate spectrum compares the apparent heat release rate for jet ignition without auto-ignition (simple jet ignition process) (represented by the dashed line 206) and the apparent heat release rate for TJCCI (represented by the solid line 208).

[0037] Contrary to the simple jet ignition process where a spark can be used in any pre-chamber, the TJCCI process can use jet ignition to control compression ignition in the main chamber. Compared to the initial heat release rate generated in the auto-ignition process of the entire pre-mixed mixture in the main chamber (such as homogeneous charge compression ignition or pre-mixed gasoline compression ignition), the benefit of performing TJCCI is a slower initial heat release rate. For example, this can be shown in the enclosed area 212. The slower initial heat release rate can reduce the rate of pressure rise during the combustion process, which can reduce the combustion noise of the engine. Additionally, during the simple jet ignition process, the heat release from combustion slows down after the first peak, which is not optimal for complete combustion and the extraction of piston work. On the other hand, TJCCI can initiate a second heat release peak, which accelerates the combustion of the remaining fuel-air mixture and improves combustion and thermal efficiency.

[0038] Furthermore, the start of combustion of TJCCI can be controlled by the spark plug 118, rather than kinetic reactions (which largely depend on the thermal boundary conditions of the engine). Under different transient operating conditions, the combustion by the spark plug 118 can be more robustly controlled.

[0039] Figure 3 Shows an engine operating map according to one or more embodiments. The TJCCI concept can be visually represented in the form of an engine operating map 300. In one or more embodiments, the engine operating map 300 can have the engine load represented on the vertical axis 304 and the engine speed represented on the horizontal axis 302.

[0040] The operating map 300 can have five distinct engine operating map regions. Each distinct engine operating map region is subject to four different combustion strategies. The first engine operating map region 306 can have engine parameters characterized by low engine speed and engine load ranging from low engine load to medium engine load. More specifically, the first set of engine parameters can include an engine speed ranging from a first minimum speed 318 to a first maximum speed 320, and an engine load ranging from a first minimum load 322 to a first maximum load 324. For example, in some embodiments, the first set of engine parameters can include an engine speed ranging from 200 to 1500 rpm and an engine load ranging from 0 bar brake mean effective pressure (BMEP) to 15 bar.

[0041] The second engine operating map region 308 can have engine parameters characterized by low engine load and engine speed ranging from low engine speed to medium engine speed. More specifically, the second set of engine parameters can include an engine speed ranging from greater than the first maximum speed 320 to a second maximum speed 326, and an engine load ranging from the first minimum load 322 to a second maximum load 328. The second maximum load 328 can be less than the first maximum load 324. For example, in some embodiments, the second set of engine parameters can include an engine speed ranging from 700 to 4,500 rpm and an engine load ranging from 0 bar to 5 bar.

[0042] When in the first and second engine operating map regions 306, 308, the engine can perform passive jet ignition combustion with a small volume of residual gas and a stoichiometric mixture, which can be represented by the following equation: (x amount of air) / (x amount of fuel)+y amount of residual gas. In one or more embodiments, the stoichiometric mixture can refer to a fuel mixture with an ideal air-to-fuel ratio of 1:1. Since the residual gas can have a low oxygen content (if any), the residual gas can be introduced into the air stream but is considered an additive to the chemical mixture. Having a small volume of residual gas can ensure that the exhaust temperature is high enough for exhaust aftertreatment while maintaining robust combustion.

[0043] The third engine operating map region 310 may have engine parameters characterized by medium engine speed and medium engine load. In one or more embodiments, at a third set of engine parameters, the engine speed ranges from a first maximum speed 320 to a second maximum speed 326, and the engine load ranges from a second maximum load 328 to a third maximum load 330. The third maximum load 330 may be less than the first maximum load 324. For example, in certain embodiments, the third set of engine parameters may include an engine speed ranging from 700 to 4,500 rpm and an engine load ranging from 3 to 12 bar. When in the third engine operating map region 310, the engine may perform TJCCI with a small volume of cooled exhaust gas recirculation (EGR) and an ultra-lean mixture. According to one or more embodiments, an ultra-lean fuel mixture may refer to a fuel mixture having a high ratio of air to fuel. For example, the ultra-lean mixture may include an amount of air that is about 1.5 - 2.5 times higher than the amount of stoichiometric fuel. Such a fluid mixture may result in high engine efficiency, high fuel efficiency, and low nitrogen oxide emissions. In particular, compared to spark or plasma-assisted compression ignition concepts, nitrogen oxide emissions may be lower due to improved fuel mixing near the spark plug 118 gap. In one or more embodiments, during a typical vehicle drive cycle, the engine may operate extensively within the third engine operating map region 310.

[0044] The fourth engine operating map region 312 may have engine parameters characterized by ranges of both engine speed and engine load from medium to high. At a fourth set of engine parameters, the engine speed may range from greater than the first maximum speed 320 to a fourth maximum speed 332 (where the fourth maximum speed 332 may be greater than the second maximum speed 326), and the engine load may generally range from greater than the third maximum load 330 to the first maximum load 324. However, it should be noted that the engine load across the fourth region 316 does not fall within a stable range and may vary according to the engine speed. For example, at speeds greater than the second maximum speed 326, the engine load may vary between the second maximum load 328 and the first maximum load 324. For example, in certain embodiments, the fourth set of engine parameters may include an engine speed ranging from 700 to 6,500 rpm and an engine load ranging from 10 to 25 bar.

[0045] When in the fourth engine operating map region 312, the engine can perform passive jet ignition combustion with a medium volume of cooled EGR and a stoichiometric mixture. Due to the high intake boost requirement, high pressure rise rate, and high peak combustion pressure, TJCCI is not applicable to high engine loads. Further, due to the long ignition delay time relative to high engine speeds, TJCCI is not applicable to high engine speeds. Instead, considering the rapid consumption of the end gas, passive jet ignition performed with a medium volume of cooled EGR and a stoichiometric mixture can improve knock compared to spark ignition under similar mixture conditions.

[0046] The fifth engine operating map 314 can have engine parameters characterized by engine shutdown. For example, in some embodiments, the fifth set of engine parameters can include an engine speed ranging from 4,000 to 6,500 rpm and an engine load ranging from 0 to 10 bar.

[0047] The mode transition region 316 can be located between the second and third engine operating regions 308, 310 and between the third and fourth engine operating regions 310, 312. When in the mode transition region 316, the engine can perform passive jet ignition with a small volume of residual gas and a stoichiometric mixture, which can be controlled by selecting different ignition timings to meet different engine load targets.

[0048] In one or more embodiments, the mode transition region 316 can represent a change in the combustion strategy, specifically, a transition from a stoichiometric mixture to a lean mixture (i.e., between the second and third engine operating map regions 308, 310) or from a lean mixture to a stoichiometric mixture (i.e., between the third and fourth operating map regions 310, 312). In one or more embodiments, the transition can be manipulated by operating the engine with a stoichiometric mixture and changing the fuel injection amount and spark timing on a cycle-by-cycle basis to reduce the work output of the crankshaft. Since stoichiometric combustion is very robust, this transition can be made more stable. However, during the mode transition region 316, the engine efficiency is reduced due to the late combustion phase required to reduce the work output.

[0049] In one or more embodiments, the computer 120 can be programmed according to the engine operating map 300. For example, the engine operating map 300 can run in the computer 120 (commonly referred to as the engine control unit, ECU), which has all the necessary engine control parameters that have been calibrated for the entire engine operating map 300. The software running in the computer 120 can be specifically written by the original equipment manufacturer (OEM) to execute with the specific engine being used.

[0050] Now turning toFigure 4 , Figure 4 shows an engine timing diagram 400 for an engine operating in first and second operating map regions 306, 308, according to one or more embodiments. An engine timing diagram (e.g., engine timing diagram 400) can represent the four strokes of the engine (exhaust, intake, compression, and expansion) and the respective timings of exhaust valve and intake valve actuations, fuel injection timings, and spark timings. Referring back Figure 1 , in one or more embodiments, each cycle of the engine can correspond to two revolutions (four strokes) of the piston 105 within the cylinder 101.

[0051] See Figure 1 and Figure 4 , during the exhaust stroke 402 of the engine, a port fuel injection procedure can be performed. In one or more embodiments, the port fuel injection procedure (visually shown in region 403) can be performed by Figure 1 the second fuel injector 108 depicted in. Further, during the exhaust stroke, the exhaust valve 114 can be actuated (visually shown by curve 404). Between the exhaust stroke 402 and the intake stroke 406, the piston 105 can reach its first top dead center position, which can be referred to as the gas exchange top dead center 408.

[0052] Shortly after the gas exchange top dead center 408 and during the intake stroke 406, the intake valve 113 can be actuated, visually depicted by curve 409. Further, after the piston 105 reaches the gas exchange top dead center 408, a direct injection fuel supply procedure 410 can be immediately performed using the first fuel injector 107. In one or more embodiments, the first fuel injector 107 can passively supply fuel to the pre - combustion chamber 117 and actively supply fuel to the main chamber 103.

[0053] The piston 105 can reach the bottom dead center position 412 between the intake stroke 406 and the compression stroke 414, and between the expansion stroke 416 and the exhaust stroke 402. The piston 105 can reach a second top dead center position between the compression stroke 414 and the expansion stroke 416, which can be referred to as the ignition top dead center 418. During the compression stroke 414 before the piston 105 reaches the ignition top dead center 418, the spark plug 118 can generate a spark 420 to ignite the fuel within the pre - combustion chamber 117.

[0054] Now referring to Figure 1 and Figure 5 , Figure 5FIG. 500 shows an engine timing diagram for an engine operating in a third operating map region 310, according to one or more embodiments. During an exhaust stroke 402 of the engine, a port fuel injection procedure may be performed. In one or more embodiments, the port fuel injection procedure (visually shown in region 403) may be performed by Figure 1 the second fuel injector 108 depicted in

[0055] Also, during the exhaust stroke, the exhaust valve 114 may be actuated (visually depicted by curve 404). Shortly after the gas exchange top dead center 408 and during an intake stroke 406, the intake valve 113 may be actuated (visually depicted by curve 409). In other words, the intake valve 113 may be actuated at the start of the intake stroke 406.

[0056] Now referring to Figure 1 and Figure 6 Figure 6 FIG. 600 shows an engine timing diagram for an engine operating in a fourth operating map region 312, according to one or more embodiments. During an exhaust stroke 402 of the engine, a port fuel injection procedure may be performed. In one or more embodiments, the port fuel injection procedure (visually shown in region 403) may be performed by Figure 1 the second fuel injector 108 depicted in

[0057] Also, during the exhaust stroke, the exhaust valve 114 may be actuated (visually depicted by curve 404). In the middle of the intake stroke 406, the intake valve 113 may be actuated (visually depicted by curve 409).

[0058] During the actuation of the intake valve 113, a direct injection fuel supply procedure 410 may be performed using the first fuel injector 107 in the middle of the intake stroke 406. In one or more embodiments, the first fuel injector 107 may passively supply fuel to the pre-chamber 117 and actively supply fuel to the main chamber 103. During a compression stroke 414 before the piston 105 reaches the ignition top dead center 418, the spark plug 118 may generate a spark 420 to ignite the fuel within the pre-chamber 117. Figure 7 Figure 7FIG. 700 shows an engine timing diagram for an engine operating in a mode transition region 316 in accordance with one or more embodiments. Referring Figure 1 and Figure 7 , during an exhaust stroke 402 of the engine, a port fuel injection procedure may be performed. In one or more embodiments, the port fuel injection procedure (visually shown in region 403) may be performed by Figure 1 the second fuel injector 108 depicted in. Further, during the exhaust stroke, the exhaust valve 114 may be actuated (visually depicted by curve 404).

[0059] Shortly after the gas exchange top dead center 408 and during an intake stroke 406, the intake valve 113 may be actuated (visually depicted by curve 409). Further, after the piston 105 reaches the gas exchange top dead center 408, a direct injection fuel supply procedure 410 may be immediately performed using the first fuel injector 107. In one or more embodiments, the first fuel injector 107 may passively supply fuel to the pre-chamber 117 and actively supply fuel to the main chamber 103.

[0060] The spark plug 118 may generate a spark 420 to ignite the fuel within the pre-chamber 117 at a selected time between a compression stroke 414 before the piston 105 reaches the ignition top dead center 418 during an engine cycle and an expansion stroke 416 after the piston 105 passes the ignition top dead center 418. The spark timing may be selected based on different engine operating requirements.

[0061] Figure 8 FIG. shows a block diagram of a computer system 802 in accordance with one or more embodiments, as described in the present disclosure, the computer system 802 being used to provide computing functionality related to the described algorithms, methods, functions, processes, flows, and programs. The illustrated computer 802 is intended to encompass any computing device, such as a server, a desktop computer, a laptop / notebook computer, a wireless data port, a smart phone, a personal data assistant (PDA), a tablet computing device, one or more processors within these devices, or any other suitable processing device, including physical instances or virtual instances (or both) of computing devices. Further, the computer 802 may include a computer including an input device (such as a button, a keyboard, a touch screen, or other device that can receive user information) and an output device (the output device conveys information related to the operation of the computer 802, including digital data, visual or audio information (or a combination of information), or a graphical user interface).

[0062] The computer 802 can serve as a client, a network component, a server, a database, or any other component (or combination of roles) of other persistent or computer systems, for performing the subject matter described in this disclosure. The illustrated computer 802 is communicatively coupled with the network 830. In some embodiments, one or more components of the computer 802 may be configured to operate within an environment including a cloud-based, on-premises, global, or other environment (or combination of environments).

[0063] At a high level, the computer 802 is an electronic computing device that can be run to receive, transmit, process, store, or manage data and information related to the subject matter described. According to certain embodiments, the computer 802 may also include or be communicatively coupled to an application server, an email server, a web server, a caching server, a streaming data server, a business intelligence (BI) server, or other servers (or combination of servers).

[0064] The computer 802 can receive requests from client applications (e.g., executing on another computer 802) via the network 830, and respond to the received requests by processing the requests in appropriate software applications. Additionally, requests may also be sent to the computer 802 from internal users (e.g., from a command console or via other appropriate access methods), external or third parties, other automated applications, and any other appropriate entities, individuals, systems, or computers.

[0065] Each component of computer 802 may communicate using system bus 803. In some embodiments, any or all components, hardware or software (or a combination of hardware and software) of computer 802 may interface with each other or interface (or a combination of both ways) using application programming interface (API) 812 or service layer 813 (or a combination of API 812 and service layer 813) through system bus 803 using interface 804. API 812 may include specifications for routines, data structures, and object classes. API 812 may be independent of or dependent on a computer language and may refer to entire interfaces, individual functions, or even groups of APIs. Service layer 813 provides software services to computer 802 or other components communicatively coupled to computer 802 (whether or not shown). The functionality of computer 802 may be accessible to all service consumers using this service layer. Software services (such as those provided through service layer 813) provide reusable, defined business functions through a defined interface. For example, the interface may be software written in JAVA, C++, or other suitable language and provide data in extensible markup language (XML) format or other suitable format. When illustrated as an integrated component of computer 802, alternative embodiments may illustrate API 812 or service layer 813 as independent components related to other components of computer 802 or other components communicatively coupled to computer 802 (whether or not shown). Additionally, any or all portions of API 812 or service layer 813 may be implemented as a sub-module or sub-component of another software module, enterprise application, or hardware module without departing from the scope of the present disclosure.

[0066] Computer 802 includes interface 804. Although Figure 8 illustrated as a single interface 804 in, two or more interfaces 804 may be used depending on the specific needs, desires, or particular embodiments of computer 802. Interface 804 is used in a distributed environment where computer 802 is connected to network 830 for communicating with other systems. Generally, interface 804 includes logic encoded in software or hardware (or a combination of software and hardware) and operable to communicate with network 830. More specifically, interface 804 may include software that supports one or more communication protocols associated with communication such that network 830 or the hardware of the interface is operable to communicate physical signals both inside and outside the illustrated computer 802.

[0067] Computer 802 includes at least one computer processor 805. Although Figure 8The figure shows a single computer processor 805, but two or more processors may be used depending on the specific needs, desires, or particular implementation of the computer 802. Generally, the computer processor 805 executes instructions and manipulates data to perform the operation of the computer 802 and any machine learning networks, algorithms, methods, functions, processes, flows, and programs as described in this disclosure.

[0068] The computer 802 also includes a memory 806 that stores data for the computer 802 or other components (or a combination of both) that may be connected to the network 830. For example, the memory 806 may be a database that stores data consistent with this disclosure. Although Figure 8 shown as a single memory 806 in the figure, two or more memories may be used depending on the described functionality and the specific needs, desires, or particular implementation of the computer 802. Although the memory 806 is shown as an integral part of the computer 802, in an alternative implementation, the memory 806 may be external to the computer 802.

[0069] The application 807 is an algorithm software engine that provides functionality depending on the specific needs, desires, or particular implementation of the computer 802, particularly with respect to the functionality described in this disclosure. For example, the application 807 may serve one or more components, modules, applications, etc. Further, although shown as a single application 807, the single application 807 may be implemented as multiple applications 807 on the computer 802. Additionally, although shown as integral with the computer 802, in an alternative implementation, the application 807 may be external to the computer 802.

[0070] There may be any number of computers 802 associated with or external to the computer system that includes the computer 802, where each computer 802 communicates via the network 830. Further, the terms "client", "user", and other appropriate terms may be used interchangeably as appropriate without departing from the scope of this disclosure. Additionally, this disclosure contemplates that many users may use one computer 802, or one user may use multiple computers 802.

[0071] Figure 9 Depicts a flowchart according to one or more embodiments. More specifically, Figure 9 Describes a flowchart 900 of a method for operating an engine under various engine operating map regions. Further, Figure 9 One or more of the tiles in may be executed by Figures 1 - 8 One or more of the components described in. Although Figure 9The respective blocks in [the figures] are presented and described sequentially, but those of ordinary skill in the art will understand that some or all of the blocks may be executed in a different order, may be combined, may be omitted, and some or all of the blocks may be executed in parallel. Additionally, the blocks may be executed actively or passively.

[0072] Initially, at S902, by performing passive jet ignition combustion with a first volume of residual gas and a first stoichiometric fuel mixture, the engine can operate in a first operating map region 306 and a second operating map region 308. In one or more embodiments, operating the engine in the first and second operating map regions 306 may involve operating the engine according to an engine timing diagram 400. Specifically, during the exhaust stroke 402 of the engine, a port fuel injection procedure 403 may be performed and the exhaust valve 114 may be actuated. At the start of the intake stroke 406, the intake valve 113 may be actuated. Additionally, during the intake stroke 406, a direct injection procedure 410 may be performed immediately after the piston 105 has passed the gas exchange top dead center 408. During the compression stroke 414, a spark may be provided from the spark plug 118 before the piston reaches the ignition top dead center 418.

[0073] Next, at S904, by performing passive jet ignition combustion with a second volume of residual gas and a second stoichiometric fuel mixture, the engine can operate in a mode transition region 316. In one or more embodiments, operating the engine in the mode transition region 316 may involve operating the engine according to an engine timing diagram 700. Specifically, during the exhaust stroke 402 of the engine, a port fuel injection procedure 403 may be performed and the exhaust valve 114 may be actuated. At the start of the intake stroke 406, the intake valve 113 may be actuated. Additionally, during the intake stroke 406, a direct injection procedure 410 may be performed immediately after the piston 105 has passed the gas exchange top dead center 408. During the compression stroke 414, a first spark may be generated immediately from the spark plug 118 before the ignition top dead center 418. Alternatively, during the expansion stroke 416, a spark may be generated immediately from the spark plug 118 after the ignition top dead center 418.

[0074] Then, at S906, by performing turbulent jet controlled compression ignition (TJCCI) with a first volume of cooled exhaust gas recirculation (EGR) and an ultra-lean fuel mixture, the engine can operate in the third operating map region 310. In one or more embodiments, operating the engine in the third operating map region 310 can involve operating the engine according to engine timing map 500. Specifically, during the exhaust stroke 402 of the engine, a port fuel injection procedure 403 can be performed and the exhaust valve 114 can be actuated. At the start of the intake stroke 406, the intake valve 113 can be actuated. During the compression stroke 414, a direct injection procedure 410 can be performed after the piston 105 has passed bottom dead center 412. Further, during the compression stroke 414, a spark can be generated immediately from the spark plug 118 before the piston 105 reaches top dead center for ignition 418.

[0075] Following the third operating map region 310, at S908, the engine can then be run one more time in the mode transition region 316. Similar to step S904, the engine can be operated according to engine timing map 700.

[0076] At S910, by performing passive jet ignition combustion with a second volume of cooled EGR and a third stoichiometric fuel mixture, the engine can also operate in the fourth engine operating map region 312. In one or more embodiments, operating the engine in the fourth engine operating map region 312 can involve operating the engine according to engine timing map 600. Specifically, during the exhaust stroke 402 of the engine, a port fuel injection procedure 403 can be performed and the exhaust valve 114 can be actuated. In the middle of the intake stroke 406, the intake valve 113 can be actuated. Further, during the intake stroke 406, during the actuation of the intake valve 113, a direct injection procedure 410 can be performed in the middle of the intake stroke 406. Further, during the compression stroke 414, a spark can be generated immediately from the spark plug 118 before the piston 105 reaches top dead center for ignition 418.

[0077] In one or more embodiments, moving from one engine operating map region to another can be controlled at least in part by a desired engine load and a desired engine speed provided by a user to a computer system (such as computers 120 and 802).

[0078] In one or more embodiments, the second volume of cooled EGR (as required in the fourth operating map region 312) can be greater than the first volume of cooled EGR (as required in the third operating map region 310).

[0079] Figure 10Depicted is a flow chart according to one or more embodiments. More specifically, Figure 10 A flow chart 1000 depicts a method for designing an engine operating under different combustion strategies. Further, Figure 10 One or more tiles in the may be represented by Figures 1 - 8 One or more of the components described in . Figure 10 The various blocks in the embodiment are presented and described sequentially, but those skilled in the art will appreciate that some or all of the blocks may be executed in a different order, may be combined, may be omitted, and some or all of the blocks may be executed in parallel. In addition, the blocks may be executed actively or passively.

[0080] Initially, S1002, the engine can be designed to operate using passive jet ignition combustion under a first set of engine parameters. In one or more embodiments, the first set of engine parameters can correspond to the engine speed and engine load of the first engine operation mapping area 306. More specifically, the first set of engine parameters can include an engine speed ranging from a first minimum speed 318 to a first maximum speed 320, and an engine load ranging from a first minimum load 322 to a first maximum load 324. In one or more embodiments, the first minimum speed 318 and the first minimum load 322 can be described as a low engine speed and a low engine load, respectively. Further, the first maximum speed 320 and the first maximum load 324 can be described as a medium engine speed and a medium engine load, respectively. Under the first set of engine parameters, the ratio of fuel to air provided in the main chamber 103 and the pre-combustion chamber 117 after injection is a stoichiometric mixture.

[0081] In one or more embodiments, the passive jet ignition combustion may include injecting fuel from the fuel injector 107 into the main chamber, wherein the amount of fuel is directed to the pre-chamber 117 through one or more nozzles. Through this injection procedure, a pre-chamber fuel-air mixture may be provided in the pre-chamber 117, and a main chamber fuel-air mixture may be provided in the main chamber 103, wherein the pre-chamber 117 is adjacent to the main chamber 103 and is in fluid communication with the main chamber 103. The passive jet ignition combustion may also include generating a spark in the pre-chamber 117 to ignite the pre-chamber fuel-air mixture, and injecting the ignited pre-chamber fuel-air mixture into the main chamber 103 to ignite the main chamber fuel-air mixture.

[0082] S1004, the engine can also be designed to operate using passive jet ignition combustion under a second set of engine parameters. In one or more embodiments, the second set of engine parameters can correspond to the engine speed and engine load of the second engine operating map region 308. More specifically, the second set of engine parameters can include an engine speed ranging from greater than the first maximum speed 320 to the second maximum speed 326, and an engine load ranging from the first minimum load 322 to the second maximum load 328. In one or more embodiments, the second maximum speed 326 and the second maximum load 328 can be described as medium engine speed and medium engine load, respectively.

[0083] In addition, S1006, the engine can be designed to change the fuel-to-air ratio provided in the main chamber 103 and the prechamber 117 to an ultra-lean ratio when the engine is operating under a third set of engine parameters. In one or more embodiments, under the third set of engine parameters, the engine speed ranges from the first maximum speed 320 to the second maximum speed 326, and the engine load ranges from the second maximum load 328 to the third maximum load 330. Further, the ultra-lean ratio includes more air than fuel.

[0084] The method depicted in the flowchart 1000 can also include providing an engine operating map that defines multiple regions of engine operation, such as the engine operating map 300. Each region of engine operation can define the fuel-to-air ratio provided in the main chamber 103 and the prechamber 117 under different engine parameters.

[0085] In one or more embodiments, the multiple regions can include a first region 306 and a second region 308. The first region 306 defines the stoichiometric ratio of fuel to air under a first set of engine parameters, and the second region 308 defines the stoichiometric ratio of fuel to air under a second set of engine parameters. A third region 310 can define the ultra-lean ratio of fuel to air under a third set of engine parameters. Under the third set of engine parameters, the engine speed can range from greater than the first maximum speed 320 to the second maximum speed 326, and the engine load can range from greater than the second maximum load 328 to the third maximum load 330. A fourth region 312 can define the stoichiometric ratio of fuel to air under a fourth set of engine parameters. Under the fourth set of engine parameters, the engine speed can range from greater than the first maximum speed 320 to the fourth maximum speed 332, and the engine load can generally range from greater than the third maximum load 330 to the first maximum load 324. However, it should be noted that the engine load across the fourth region 316 does not fall within a stable range and can vary according to the engine speed. For example, when the speed is greater than the second maximum speed 326, the engine load can vary between the second maximum load 328 and the first maximum load 324.

[0086] In one or more embodiments, the engine operating map 300 may further define a third region 310 as having a first amount of cooled EGR provided with an ultra-lean ratio of fuel to air. Further, a fourth region 312 may be defined as having a second amount of cooled EGR provided with a stoichiometric ratio of fuel to air. In one or more embodiments, the second amount of cooled EGR may be greater than the first amount of EGR. Additionally, operating the engine at various different regions and corresponding timing parameters includes performing fuel injection at different times as the piston 105 cycles through the main chamber 103.

[0087] Embodiments of the present disclosure may provide at least one of the following advantages. Turbulent jet controlled compression ignition may assist in fuel mixing and vaporization within the pre-chamber prior to jetting into the main chamber. Since only a spark plug needs to be installed within the pre-chamber, allowing passive fuel supply to the pre-chamber permits the maintenance of a small pre-chamber volume. In contrast, in embodiments of an engine where a fuel injector is installed within the pre-chamber, it is necessary for the pre-chamber to be larger in volume, which is undesirable. Additionally, direct pre-chamber fuel injection reasonably reduces the time and distance that the fuel may need to vaporize. Embodiments of the present disclosure relying on passive pre-chamber fuel supply allow sufficient time and distance to promote sufficient mixing and vaporization of the fuel.

[0088] The implementation of TJCCI in place of spark-assisted gasoline compression ignition enables an improved repeatability of the cyclicity of the local equivalence ratio of the fuel-air mixture stratified in the spark gap. With the addition of a pre-chamber nozzle through which fuel can be accelerated into the pre-chamber, a high-speed flow into the pre-chamber can be created during the compression stroke, which promotes mixing within the mixture to produce a uniform fuel mixture. The continuation of this process throughout the compression stroke results in the accumulation of fuel within the pre-chamber, which creates an optimal equivalence ratio mixture for earlier fuel injection timing within the pre-chamber. The reduction of the local equivalence ratio facilitated by TJCCI ensures robust and strong flame propagation within the pre-chamber, resulting in reduced nitrogen oxide emissions.

[0089] Although only a few exemplary embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the invention. Accordingly, all such modifications are intended to be included within the scope of the present disclosure as defined by the following claims.

Claims

1. A method, comprising: Operate the engine in a first engine operating map region and a second engine operating map region by performing passive jet ignition combustion with a first volume of residual gas and a first stoichiometric fuel mixture; Operate the engine in a mode transition region by performing passive jet ignition combustion with a second volume of residual gas and a second stoichiometric fuel mixture, wherein the second volume of the residual gas is controlled by ignition timing to meet a target engine load; Operate the engine in a third engine operating map region by performing turbulence jet controlled compression ignition (TJCCI) with a first volume of cooled exhaust gas recirculation and an ultra-lean fuel mixture; Operate the engine in the mode transition region; Operate the engine in a fourth engine operating map region by performing passive jet ignition combustion with a second volume of cooled exhaust gas recirculation and a third stoichiometric fuel mixture; and Operate the engine in a fifth engine operating map region, wherein the fifth engine operating map region is characterized by the engine being shut down, wherein one cycle of the engine spans two reciprocations of a piston within the engine, and wherein the cycle includes: an exhaust stroke, an intake stroke, a compression stroke, and an expansion stroke; a gas exchange top dead center piston position located between the exhaust stroke and the intake stroke; an ignition top dead center piston position located between the compression stroke and the expansion stroke; and a bottom dead center piston position located between the intake stroke and the compression stroke and between the expansion stroke and the exhaust stroke.

2. The method according to claim 1, wherein operating the engine in a first engine operating map region and a second engine operating map region comprises: During the exhaust stroke of the engine: Execute a port fuel injection procedure; and Actuate an exhaust valve; During the intake stroke of the engine: Actuate an intake valve at the start of the intake stroke; and Execute a direct injection fuel supply procedure immediately after the gas exchange top dead center piston position; and During the compression stroke of the engine: Provide a spark immediately from a spark plug before the ignition top dead center piston position.

3. The method according to claim 1 or 2, wherein operating the engine in a third engine operating map comprises: During the exhaust stroke of the engine: Execute a port fuel injection procedure; and Actuate an exhaust valve; During the intake stroke of the engine: Actuate an intake valve; and During the compression stroke of the engine: Execute a direct injection fuel supply procedure at the start of the compression stroke; and Provide a spark immediately from a spark plug before the ignition top dead center piston position.

4. The method according to any one of claims 1 - 3, wherein operating the engine in a fourth engine operating map includes: During the exhaust stroke of the engine: Execute a port fuel injection procedure; and Actuate an exhaust valve; During the intake stroke of the engine: Actuate an intake valve in the middle of the intake stroke; and Execute a direct injection fuel supply procedure in the middle of the intake stroke; and During the compression stroke of the engine: Provide a spark immediately from a spark plug before the ignition top dead center piston position.

5. The method according to any one of claims 1 - 4, wherein operating the engine in the mode transition region includes: During the exhaust stroke of the engine: Execute a port fuel injection procedure; and Actuate an exhaust valve; During the intake stroke of the engine: Actuate an intake valve at the start of the intake stroke; and Execute a direct injection fuel supply procedure immediately after the gas exchange top dead center piston position; During the compression stroke of the engine: Before the ignition top dead center piston position, provide a first spark immediately from the spark plug; And During the expansion stroke of the engine: After the ignition top dead center piston position, provide a second spark immediately from the spark plug.

6. The method according to any one of claims 1 - 5, wherein a second volume of the cooled exhaust gas recirculation is greater than a first volume of the cooled exhaust gas recirculation.

7. The method according to any one of claims 1 - 6, further comprising moving from one engine operating map region to another engine operating map region at least partially based on a desired engine load and a desired engine speed provided by a user to a computer processor.

8. A turbulent jet controlled compression ignition (TJCCI) engine system, comprising: An engine block with cylinders; A piston configured to move up and down inside the main chamber of the cylinder; A pre-chamber in fluid communication with the main chamber; A fuel injector mounted to the engine block and in fluid communication with the main chamber; And A computer system, having a memory and a processor, communicating with the piston, exhaust valve, intake valve, spark plug, and one or more fuel injectors, wherein the processor is configured to: Run the engine in a first engine operating map region and a second engine operating map region by performing passive jet ignition combustion with a first volume of residual gas and a first stoichiometric fuel mixture; Run the engine in a mode transition region by performing passive jet ignition combustion with a second volume of residual gas and a second stoichiometric fuel mixture, wherein the second volume of the residual gas is controlled by ignition timing to meet a target engine load; Run the engine in a third engine operating map region by performing turbulence jet controlled compression ignition (TJCCI) with a first volume of cooled exhaust gas recirculation and an ultra-lean fuel mixture; Run the engine in the mode transition region; Run the engine in a fourth engine operating map region by performing passive jet ignition combustion with a second volume of cooled exhaust gas recirculation and a third stoichiometric fuel mixture; and Run the engine in a fifth engine operating map region, wherein the fifth engine operating map region is characterized by the engine being shut down.

9. The TJCCI engine system according to claim 8, wherein one cycle of the engine spans two reciprocations of the piston within the engine, and the cycle includes: Exhaust stroke, intake stroke, compression stroke, and expansion stroke; A gas exchange top dead center piston position located between the exhaust stroke and the intake stroke; An ignition top dead center piston position located between the compression stroke and the expansion stroke; And A bottom dead center piston position located between the intake stroke and the compression stroke and between the expansion stroke and the exhaust stroke.

10. The TJCCI engine system according to claim 9, wherein when the engine is operating in the first engine operating map region and the second engine operating map region, the computer system is further configured to: During the exhaust stroke of the engine: Actuate a first fuel injector among the one or more fuel injectors in the port of the engine located adjacent to the main chamber; And Actuate the exhaust valve; During the intake stroke of the engine: Actuate the intake valve at the start of the intake stroke; And Actuate a second fuel injector among one or more fuel injectors located in the main chamber immediately after the gas exchange top dead center piston position; And During the compression stroke of the engine: Before the ignition top dead center piston position, immediately actuate the spark plug located in the pre-chamber.

11. The TJCCI engine system according to claim 9 or 10, wherein when the engine is operating in the third engine operating map region, the computer system is further configured to: During the exhaust stroke of the engine: Actuate a first fuel injector among the one or more fuel injectors in the port of the engine located adjacent to the main chamber; And Actuate the exhaust valve; During the intake stroke of the engine: Actuate the intake valve; And During the compression stroke of the engine: At the start of the compression stroke, actuate a second fuel injector among one or more fuel injectors located in the main chamber; And Before the ignition top dead center piston position, immediately actuate the spark plug located in the pre-chamber.

12. The TJCCI system according to any one of claims 9 to 11, wherein, When the engine is operating in the fourth engine operating map region, the computer system is further configured to: During the exhaust stroke of the engine: Actuate a first fuel injector among the one or more fuel injectors in the port of the engine positioned adjacent to the main chamber; And Actuate the exhaust valve; During the intake stroke of the engine: Actuate the intake valve in the middle of the intake stroke; And During the middle of the intake stroke, actuate a second fuel injector among the one or more fuel injectors in the main chamber; And During the compression stroke of the engine: Immediately before the ignition top dead center piston position, actuate the spark plug located in the prechamber.

13. The TJCCI system according to any one of claims 9 to 12, wherein when the engine is operating in the mode transition region, the computer system is further configured to: During the exhaust stroke of the engine: Actuate a first fuel injector among the one or more fuel injectors in a port of the engine positioned adjacent to the main chamber; And Actuate the exhaust valve; During the intake stroke of the engine: Actuate the intake valve at the start of the intake stroke; And Immediately after the gas exchange top dead center piston position, actuate a second fuel injector among the one or more fuel injectors in the main chamber; During the compression stroke of the engine: Immediately before the ignition top dead center piston position, actuate the spark plug located in the prechamber to generate a first spark; And During the expansion stroke of the engine: Immediately after the ignition top dead center piston position, actuate the spark plug located in the prechamber to generate a second spark.

14. The TJCCI engine system according to any one of claims 9 to 13, wherein one of the one or more fuel injectors is positioned in the main chamber and configured to passively supply fuel to the pre - combustion chamber.

15. The TJCCI engine system according to any one of claims 8 to 14, wherein the first engine operating map region and the second engine operating map region are characterized by low engine speed, low engine load, or both.

16. The TJCCI engine system according to any one of claims 8 to 15, wherein the third engine operating map region is characterized by low to medium engine speed and low to medium engine load.

17. A method, comprising: Design the engine to operate using passive jet ignition combustion under a first set of engine parameters, where the passive jet ignition combustion includes: Inject fuel from a fuel injector into the main chamber of the engine such that an amount of the fuel is directed into the prechamber to provide a prechamber fuel-air mixture in the prechamber and a main chamber fuel-air mixture in the main chamber, where the prechamber is adjacent to the main chamber and in fluid communication with the main chamber; Generate a spark in the prechamber to ignite the prechamber fuel-air mixture; and Inject the ignited prechamber fuel-air mixture from the prechamber into the main chamber to ignite the main chamber fuel-air mixture, Wherein the first set of engine parameters includes: An engine speed ranging from a first minimum speed to a first maximum speed; and An engine load ranging from a first minimum load to a first maximum load, and Wherein, under the first set of engine parameters, the fuel-to-air ratio provided in the main chamber and the prechamber after the injection is stoichiometric; Design the engine to operate using passive jet ignition combustion under a second set of engine parameters, the second set of engine parameters including: An engine speed ranging from greater than the first maximum speed to a second maximum speed; and An engine load ranging from the first minimum load to a second maximum load, and Design the engine to change the fuel-to-air ratio provided in the main chamber and the prechamber to an ultra-lean ratio when the engine is operating under a third set of engine parameters, Wherein, under the third set of engine parameters, the engine speed is greater than the first maximum speed and the engine load is greater than the second maximum load, and Wherein, the ultra-lean ratio includes more air than fuel.

18. The method according to claim 17, further comprising: An engine operation map defining a plurality of regions of engine operation is provided, wherein each region defines the ratio of fuel to air provided in the main chamber and the pre-chamber under different engine parameters, and the plurality of regions include: A first region defining the stoichiometric ratio of fuel to air under the first set of engine parameters; A second region defining the stoichiometric ratio of fuel to air under the second set of engine parameters; A third region defining the ultra-lean ratio of fuel to air under the third set of engine parameters, wherein the third set of engine parameters further includes: An engine speed ranging from greater than the first maximum speed to the second maximum speed; and An engine load ranging from greater than the second maximum load to the third maximum load; and A fourth region defining the stoichiometric ratio of fuel to air under the fourth set of engine parameters, wherein the fourth set of engine parameters includes: An engine speed ranging from greater than the first maximum speed to the fourth maximum speed; and An engine load ranging from greater than the third maximum load to the first maximum load.

19. The method according to claim 18, wherein the engine operating map further defines the third region and the fourth region, the third region being defined as having a first amount of cooled EGR with the ultra-lean ratio of fuel to air provided, and the fourth region being defined as having a second amount of cooled EGR with the stoichiometric ratio of fuel to air provided, wherein the second amount of cooled EGR is greater than the first amount.

20. The method according to any one of claims 17 to 19, wherein operating the engine at different engine parameters includes performing the injection at different times while the piston cycles in the main chamber.

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