CN116537983A - Fuel injector with spray conduit sized for optimized soot reduction - Google Patents

Abstract

A fuel injector includes a nozzle body having spray orifices formed therein each defining a spray orifice diameter dimension (d); and a plurality of spray conduits each aligned with one of the plurality of spray orifice spray paths and including a conduit outlet defining a conduit discharge outlet diameter dimension (D). Each of the spray pipes together with a respective one of the spray apertures defines a relative Spray Area Reduction (SAR) at the pipe outlet. The ratio of D/D is at least 14 and SAR is 80% or greater. This configuration provides reduced smoke generation. Related methods are disclosed.

Description

Fuel injector with spray conduit sized for optimized soot reduction

Technical Field

The present disclosure relates generally to a ducted fuel injector, and more particularly to a fuel injector spray duct optimized for soot reduction.

Background

An internal combustion engine is configured with one or more combustion cylinders, each combustion cylinder associated with a piston to define a combustion chamber. Fuel is delivered to the combustion chamber for combustion with air by a variety of techniques. In some engines, fuel is injected directly through a fuel injector supported in the engine housing. Such fuel injectors typically include a plurality of spray orifices, the opening and closing of which is controlled by an outlet check.

Compression ignition fuels are widely used throughout the world in engine applications ranging from vehicle propulsion to power generation, as well as in the operation of pumps, compressors, and various types of industrial equipment. Such fuels (particularly diesel distillate fuels) can produce various undesirable exhaust emissions. These undesirable emissions often must be trapped for later disposal or otherwise treated to limit their discharge to the environment. Particulate matter (mainly soot) is one such undesirable exhaust gas constituent. Although soot may be trapped in a diesel particulate filter or DPF and subsequently combusted, in situ reduction of soot generation has received considerable attention in recent years.

Fuel injectors are known that utilize a conduit to reduce smoke formed within a combustion chamber during engine operation. Such spray conduits typically include a tubular structure positioned to receive a jet of fuel from a fuel injector. As the fuel jet advances through the spray conduit, air is entrained into the plume that is ultimately discharged into the combustion chamber. The spray conduit may, among other characteristics, increase the so-called "float length" of the fuel jet and thereby further enhance the mixing of air with the injected fuel prior to initiation of combustion.

One known pipe fuel injector is set forth in U.S. patent No. 10,012,196B1 and titled Duct Structure for Fuel Injector Assembly. The known pipe fuel injection device appears to show considerable promise for widespread use. Nevertheless, the art still provides sufficient room for improvement and development of alternative strategies.

Disclosure of Invention

In one aspect, a fuel injector includes a nozzle body having a plurality of spray orifices formed therein, and each of the plurality of spray orifices defines a spray orifice diameter dimension (d). The fuel injector further includes a plurality of spray conduits each aligned with one of the plurality of spray orifice spray paths and including a conduit outlet defining a conduit outlet diameter dimension (D). Each of the plurality of spray pipes together with a respective one of the plurality of spray orifices define a relative Spray Area Reduction (SAR) at the pipe outlet. The ratio of D/D is at least 10 and SAR is 80% or greater.

In another aspect, a method of operating an engine includes injecting a fuel jet from a spray orifice of a fuel injector, and advancing the fuel jet through spray conduits each having a conduit outlet. The method further includes entraining an amount of air within each respective spray conduit sufficient to produce a minimum equivalence ratio of 2.5 at the conduit outlet with each fuel jet, and impinging each combustion jet of the fuel jets on a conduit wall within each respective spray conduit to limit diffusion of the spray area of each fuel jet by 80% or more. The method further includes advancing the fuel jet into a combustion chamber in the engine, and compressing the fuel jet in the combustion chamber.

In yet another aspect, an internal combustion engine system includes: an internal combustion engine having a combustion cylinder formed therein; and a fuel injector including a plurality of spray orifices formed therein, and a plurality of spray conduits each aligned with one of the plurality of spray orifices. Each of the plurality of spray orifices defines a spray orifice diameter dimension (d). Each of the plurality of spray conduits includes a conduit outlet, each conduit outlet defining a conduit discharge outlet diameter dimension (D) and being positioned at a spaced distance from a corresponding one of the plurality of spray apertures. The relative Spray Area Reduction (SAR) of each of the plurality of spray pipes is based on D, D and the separation distance, and the SAR is about 80% or greater.

Drawings

FIG. 1 is a partial cross-sectional diagrammatic view of an internal combustion engine system according to one embodiment;

FIG. 2 is a cross-sectional diagrammatic view of a portion of the engine system as in FIG. 1;

FIG. 3 is a diagrammatic view of a spray conduit having a spray cross section in accordance with an embodiment;

FIG. 4 is a graph of spray area reduction compared to float length;

FIG. 5 is a graph of spray area reduction compared to apparent soot reduction;

FIG. 6 is a plot of duct outlet to spray orifice diameter ratio compared to minimum duct outlet equivalence ratio;

FIG. 7 is a graph of spray area reduction as a function of duct diameter and discharge port spacing; and

fig. 8 is a graph comparing the pipe diameter to the area reduction ratio.

Detailed Description

Referring to FIG. 1, an internal combustion engine system 10 is shown according to one embodiment. The engine system 10 includes an internal combustion engine 12 having an engine housing 14 with combustion cylinders 16 formed therein. Cylinder 16 may be one of any number and in any suitable arrangement. Piston 18 may be movable within cylinder 16 between a top dead center position and a bottom dead center position, typically in a conventional four-stroke mode, to increase the pressure in cylinder 16 to an auto-ignition threshold. In an embodiment, engine system 10 is compression ignition, wherein piston 18 is movable within cylinder 16 to increase the pressure of the fluid therein to an auto-ignition threshold during a compression stroke. The piston 18 and any other such pistons in the engine system 10 are coupled to the crankshaft 22 in a generally conventional manner. A plurality of engine valves 20 (including, for example, two intake valves and two exhaust valves) are supported in the engine housing 14 and are movable to also control fluid communication between the cylinders 16 and the intake and exhaust manifolds in a generally conventional manner. The engine system 10 may be used to operate a generator, pump, compressor, or transmission to propel a vehicle, to name a few. Additional devices not shown in fig. 1 may include an intake system having a compressor in a turbocharger, and an exhaust system including, for example, a turbine in the turbocharger and an exhaust aftertreatment device.

The engine system 10 further includes a fuel system 24 having a fuel supply 26, a low pressure pump 28, and a high pressure pump 30. The high pressure pump 30 provides a feed of pressurized fuel to a fuel conduit 31 that extends to a fuel injector 32. The fuel conduit 31 may be connected to or itself may be a pressurized fuel reservoir that maintains a supply of pressurized fuel at injection pressure for a plurality of fuel injectors in the engine system 10. Fuel injectors 32 may include at least one electrically actuated valve 44 that controls the operation of fuel injectors 32 to inject pressurized fuel into cylinders 16. In practical embodiments, the fuel comprises diesel distillate fuel, however, the disclosure is not so limited and other compression ignition fuels or even relatively low cetane fuels mixed with cetane boost may be used. Electronic control unit 34 is coupled to fuel injector 32 and energizes and de-energizes electric actuator 44 in a generally known manner to control the timing of fuel injection and sometimes the manner in which fuel injection is controlled. The fuel injector 32 is also equipped with a spray conduit 50 that extends into the cylinder 16 and is attached to the fuel injector 32 or the engine housing 14. As will be further apparent from the following description, spray conduit 50 is uniquely configured by optimizing size and/or positioning to provide reduced smoke generation during operation of engine system 10 as compared to certain other ducted and non-ducted fuel injector designs.

Referring now also to FIG. 2, additional features of the engine system 10 are shown in greater detail. The fuel injector 32 may include a nozzle body 36 that extends into the cylinder 16 and is supported in the engine housing 14. The nozzle body 36 includes a plurality of spray orifices 40 formed therein. The fuel injector 32 also includes an outlet check 38 that is movable generally along a central axis 46 of the fuel injector 32 to control fluid communication between the spray orifice 40 and the pressure chamber volume 42. The outlet check 38 may be directly controlled based on the position of a control valve operated by the electric actuator 44, such as by applying and releasing a closing hydraulic pressure on a hydraulic control surface of the outlet check 38. The spray apertures 40 are oriented transverse to the axis 46 and may include any number, e.g., from 3 to 7, and are circumferentially spaced about the axis 46.

The fuel injector 32 also includes a plurality of spray conduits 50 as described above. The spray conduits 50 are each aligned with one of the spray orifice spray paths of the plurality of spray orifices 40. Spray path alignment means that the central axis of the fuel spray jet extends through the spray conduit generally (but not necessarily) parallel to the longitudinal axis of the spray conduit. Fuel jet 60 is shown advancing from spray conduit 50 into cylinder 16. The jets 60 are shown as they may only begin to fire at a float length 52 spaced outwardly from the respective spray conduit 50. As discussed further herein, the spray conduit 50 may be configured to sometimes balance competing factors of air entrainment sufficient to provide a desired equivalence ratio and velocity to provide a desired float length.

Referring now to fig. 3, one of the plurality of spray conduits 50 (hereinafter sometimes referred to in the singular) is shown as it might be present adjacent to the spray orifice 40 and receive the fuel jet 60 injected from the orifice 40. Each of the plurality of spray orifices 40 may define a spray orifice diameter dimension (d) identified in fig. 3 by reference numeral 90. The spray conduit 50 includes a conduit inlet 54 and a conduit outlet 56. The duct outlet 56 defines a duct outlet diameter dimension (D). The spray conduit 50 includes a conduit inner wall 58 that may be cylindrical and uniform in diameter from the conduit inlet 54 to the conduit outlet 56. The spray conduit 50 is spaced apart from the spray orifice 40 by a first distance G. The duct outlet 56 in the spray duct 50 is spaced from the duct inlet 54 by a duct length distance L that is different from and in the illustrated embodiment greater than the first distance G. In other cases, the conduit length distance may be less than a similar first distance, so the distance between the conduit inlet and the conduit outlet may be less than the distance from the spray orifice to the conduit inlet. The separation distance of each duct outlet 56 is defined as the sum of the first distance G and the duct length distance L. In an embodiment, the ratio of D/D is at least 10. In a modification, the ratio of D/D is at least 14, and in another modification, the D/D is 14.5 or greater.

The spray conduit 50 also defines a relative Spray Area Reduction (SAR) at a respective conduit outlet 56 with a respective one of the spray apertures 40. The SAR may be 80% or greater, and in a modification, the SAR may be 85% or greater. As can be seen in fig. 3, as the fuel jet 60 progresses from the spray orifice 40 into the spray conduit 50, the fuel jet spreads at a spread angle 101. As discussed further herein, the diffusion angle 101 may be 15 ° to 30 °, and generally varies with orifice size and cylinder internal density. However, the jet 60 impinges on the conduit wall 58 before reaching the conduit outlet 56. Thus, continued spreading of the spray area of jet 60 is constrained by the impact. At the duct outlet 56, the jet 60 has a reduced constrained spray area (spray cross-sectional area) compared to an unconstrained spray area jet 60 without impingement. In other words, the spray conduit 50 reduces the spread of the jet 60. However, in accordance with well known principles, the reduction in the available area of the jet 60 within the spray conduit 50 increases the velocity of the jet 60 and helps to provide the desired float length from the spray conduit 50 (where combustion within the cylinder 60 begins).

As can also be seen in the end view of the spray conduit 50 depicted in fig. 3, the jet 60 may have an actual diameter D and an actual spray area 70. An additional expected spray area that can be observed in the absence of impingement on the inner wall 58 of the pipe is shown at 80. It is contemplated that the spray area may or may not be greater than the outer diameter dimension of the spray conduit 50. It has been found that in some cases it is desirable that the inner conduit diameter D be large enough to allow sufficient air entrainment so that the equivalent of mixed fuel and air exiting the spray conduit 50 (generally at the conduit outlet 56) is relatively low. In one practical embodiment, a minimum equivalence ratio of 2.5 is desired, meaning that the ratio of stoichiometric air-fuel ratio (AFR) to actual AFR is at least 2.5.

The desired minimum equivalence ratio limit with respect to the pipe geometry can be further understood according to equation 1 below:

wherein:

ρ _{fuel and its production process} Fuel density =

ρ _{Air-conditioner} Air Density =

AFR _stoich And D are as discussed herein. Thus, it can be appreciated that the relationship between the optimally reduced duct outlet diameter, spray orifice diameter, and minimum to desired equivalence ratio at the duct outlet, which brings about soot generation, according to the present disclosure.

It should be appreciated that as the fuel jet travels through the conduit, the jet is injected through the air. If the diameter of the tube (including the tube outlet diameter) is too small, the fuel spray will occupy a large portion of the volume through the tube, such that little or no space is available for theoretically entrainable air. However, as noted above, it has also been observed that reducing the jet cross-sectional area (spray area) is desirable to increase the velocity of the jet. Thus, if the duct outlet is too large, the spray area of the jet cannot be reduced sufficiently to achieve a sufficient increase in jet velocity to achieve the desired float length.

As mentioned, each spray conduit 50 together with the spray orifice 40 defines a relative spray area reduction SAR at the respective conduit outlet 56. With other factors being equal, a larger spray orifice may be associated with a larger local equivalent ratio, while with other factors being equal, a smaller spray orifice may be associated with a lower local equivalent ratio. It should also be remembered that the first length G plus the pipe length L defines the separation distance. The spacing distance of the duct outlets 56 may be extended to provide a relatively large spray area reduction, or reduced to provide a relatively small spray area reduction. The present disclosure provides a balance of these various factors to achieve an optimized reduced spray conduit size and arrangement that results in smoke generation.

Focusing now on fig. 4, a graph 100 is shown showing the spray area reduction on the X-axis compared to the float length on the Y-axis. The first line 110 shows what can be observed at 800K in an exemplary duct fuel jet in accordance with the present disclosure and associated with a 0.150 millimeter spray orifice. The second line 120 shows what is observable at 900K in another exemplary conduit jet employing a spray conduit with a spray orifice of 0.150 millimeters configured in accordance with the present disclosure. The third line 130 shows what can be observed in a further duct jet employing a jet duct configured in accordance with the present disclosure. The line 130 data may be obtained using a 0.150 mm spray orifice at 1000K. It can be seen that the spray area reduction in the example provided by lines 110, 120 and 130 shows a significantly increased float length after approximately 80% Spray Area Reduction (SAR) and most notably starting at approximately 85% Spray Area Reduction (SAR). The designation "free jet" in fig. 4 identifies data for 3 points at different combinations of orifice size and temperature (as might be expected in the case of 0% SAR and thus non-plumbing).

Focusing now on fig. 5, a graph 200 is shown showing the spray area reduction on the X-axis compared to the apparent soot reduction on the Y-axis. Line 210 is based on data available at 800K using a 0.150 millimeter spray orifice. Line 220 is based on data available at 900K using a 0.150 millimeter spray orifice. Data for line 230 may be obtained using a 0.150 millimeter spray orifice at 1000K, and data for line 240 may be obtained using a 0.219 millimeter spray orifice at 1000K. It can be seen that the apparent smoke reduction increases sharply after an 80% Spray Area Reduction (SAR), and begins to increase most sharply at about an 85% Spray Area Reduction (SAR). It should also be noted that for the various data points, the minimum duct outlet equivalence ratio shown next to the individual data points increases with increasing apparent soot reduction. However, at Spray Area Reductions (SAR) between 85% and 90%, apparent soot reduction begins to decrease. It is believed that the limitation on apparent soot reduction is due to the Spray Area Reduction (SAR) becoming large enough that entrainment of air decreases and the jet begins to become undesirably enriched, resulting in increased soot.

Focusing now on FIG. 6, a comparison of the ratio D/D on the X-axis compared to the minimum plumbing discharge equivalent ratio on the Y-axis is shown in curve 300. In curve 300, line 310 shows the minimum line drain equivalence ratio at 120 bar cylinder pressure, and line 320 shows the minimum line drain equivalence ratio at 60 bar cylinder pressure. A target minimum plumbing discharge equivalence ratio of about 2.5 is shown at dashed line 330. It should be recalled that the ratio of D/D is desirably at least 14, and more desirably 14.5 or greater. Thus, to achieve a desired or target minimum equivalent ratio of about 2.5 or greater, a ratio of D/D of at least 14 and more desirably 14.5 or greater may be used. However, under certain conditions, a D/D ratio of about 10 or greater may be desired. Configuring the fuel injectors and the conduits based on the equivalence ratio observable at 60 bar may ensure that the desired soot reduction characteristics are observed over a sufficiently wide range of engine operating conditions.

Focusing now on fig. 7, another graph 400 is shown showing the drain spacing on the Y-axis and the tube diameter on the X-axis. The spray area reduction is shown by the legend on the right side of the graph 400. It can also be seen that a Spray Area Reduction (SAR) target at or near 85% (shown generally between diagonal dashed lines 102 in fig. 7) can be observed for a range of discharge opening spacing distances that increases with increasing pipe diameter. In other words, the graph 400 shows that one or both of the pipe diameter and the discharge spacing may be varied and still achieve a target SAR. At a discharge gap distance of about 25 mm, a SAR of about 85% can be obtained at a pipe diameter of approximately 4 mm. At a short discharge gap distance of, for example, 10 mm, a SAR of about 85% can be obtained at a pipe diameter of approximately 2 mm. In graph 400, dashed line 410 shows a drain spacing distance of about 17 millimeters and a conduit diameter of between about 2 millimeters and about 2.5 millimeters that is slightly greater than 2 millimeters. In at least some cases, the use of a larger vent spacing distance may suggest the use of a larger conduit diameter, while the use of a smaller vent spacing distance may suggest the use of a smaller conduit diameter.

In view of fig. 7, it can be appreciated that increased discharge outlet spacing can maintain a generally desired spray area reduction range with increasing conduit diameter, and vice versa. However, it should be remembered that extending the discharge outlet spacing causes the fuel jet to impinge at a location in the spray conduit relatively far from the conduit outlet (toward the spray orifice). However, if the discharge openings are made too large apart, the jet stream may begin to fire within the conduit itself. However, as discussed above, if the drain spacing is made too short, it may be desirable to reduce the pipe diameter to the point where the equivalence ratio becomes too rich.

Focusing now on fig. 8, a graph 500 is shown showing the diameter of the tube on the X-axis compared to the spray area reduction ratio (SAR) on the Y-axis. Dashed line 550 shows a target area reduction ratio of approximately 85%. Line 510 shows what might be expected using a 0.150 mm spray orifice at 900K and 120 bar cylinder pressure. Line 520 shows what might be expected using a 0.219 mm spray orifice at 1000K and 120 bar cylinder pressure. Line 530 shows what can be seen using a 0.150 millimeter spray orifice at 900K and 60 bar cylinder pressure, and line 540 shows what can be seen using a 0.219 millimeter spray orifice at 1000K and 60 bar cylinder pressure. Following generally fig. 8 and other teachings herein, a fuel injector having a range of sized spray conduits and having a range of sized spray orifices suitable for a range of engine operating conditions may be implemented. The spray orifice according to the present disclosure may define a spray orifice diameter dimension D of from 0.09 millimeters to 0.35 millimeters (from 0.09 millimeters to 0.28 millimeters in a modification), and the conduit discharge opening diameter D may be in the range of 1.3 millimeters to 4.0 millimeters. For example, some practical applications may include fuel injectors having spray orifices at 0.09 millimeters, at 0.150 millimeters, or at 0.275 millimeters. In some embodiments, certain practical applications may include a pipe discharge opening diameter at 1.3 millimeters, 2.2 millimeters, 3.4 millimeters, or 4.0 millimeters. The drain gap distance may be in the range of 10 mm to 30 mm.

In many cases, a fuel injector according to the present disclosure will have spray orifices, spray conduit discharge ports, and spacing distances that are all uniform in size, however in some embodiments, different sized orifices, different sized conduits, or even different spacing distances may be used within the same fuel injector. Furthermore, while the spray orifices will typically all be fluidly connected to the nozzle chamber/pressure chamber volume at the same time, in some embodiments, the two outlet check may be independently controlled to selectively inject fuel through different sets of pipe spray orifices or even through a set of pipe spray orifices and a set of non-pipe spray orifices.

INDUSTRIAL APPLICABILITY

Referring generally to the drawings, operating the engine system 10 may include injecting a fuel jet from a spray orifice 40 of a fuel injector 32, and advancing the fuel jet through a spray conduit 50 each having a conduit outlet 56. Operating engine system 10 may further include entraining an amount of air within the respective spray conduit with each jet sufficient to produce a minimum equivalence ratio of approximately 2.5 at the conduit outlet. Within each respective spray conduit 50, each of the fuel jets may impinge on the conduit wall 58 to limit the spread of the spray area of each jet by 80% or more, and more specifically by 85% or more in some embodiments. The fuel jet may proceed from spray conduit 50 into a combustion chamber or cylinder 16 in engine 12 and the fuel jet is ignited by compression ignition therein.

This description is for illustrative purposes only and should not be construed to narrow the scope of the present disclosure in any way. Those skilled in the art will therefore appreciate that various modifications might be made to the presently disclosed embodiments without departing from the full and fair scope and spirit of the present disclosure. Other aspects, features, and advantages will become apparent from a review of the attached drawings and the appended claims. As used herein, the articles "a" and "an" are intended to include one or more items and are used interchangeably with "one or more". The term "about" or similar related terms generally or approximately refer to a measurement error or another tolerance as would be understood by one of ordinary skill in the relevant art, such as being conventionally rounded to a consistent number of significant digits. The term "one" or similar language is used when intended to mean that there is only one item. Further, as used herein, the terms "having", and the like are intended to be open-ended terms. Furthermore, the phrase "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise.

Claims (15)

1. A fuel injector, comprising:

a nozzle body having a plurality of spray orifices formed therein, and each defining a spray orifice diameter dimension (d);

a plurality of spray conduits each aligned with one of the plurality of spray orifice spray paths and including a conduit outlet defining a conduit discharge outlet diameter dimension (D);

each of the plurality of spray pipes together with a respective one of the plurality of spray orifices defining a relative Spray Area Reduction (SAR) at the pipe outlet;

the ratio of D/D is at least 10; and is also provided with

The SAR is 80% or greater.

2. The fuel injector of claim 1, wherein D/D is 14 or greater and the SAR is 85% or greater.

3. The fuel injector of claim 1 or 2, wherein each of the spray conduits defines a uniform diameter fuel jet passage from a conduit inlet to a respective conduit outlet.

4. A fuel injector according to any one of claims 1-3, wherein:

each of the plurality of spray conduits is spaced a first distance from a respective one of the plurality of spray apertures, and each respective conduit outlet is spaced a conduit length distance from the conduit inlet;

the separation distance of each conduit outlet is defined as the sum of the first distance and the conduit length distance; and is also provided with

The separation distance is 10 mm to 30 mm.

5. The fuel injector of any one of claims 1-4, wherein:

d is 0.09 mm to 0.35 mm; and is also provided with

D is 1.3 mm to 4.0 mm.

6. A method of operating an engine, comprising:

injecting a fuel jet from a spray orifice of a fuel injector;

advancing the fuel jet through spray pipes each having a pipe outlet;

entraining an amount of air with each fuel jet in the respective spray conduit sufficient to produce a minimum equivalence ratio of 2.5 at the conduit outlet;

impinging each of the fuel jets on a conduit wall within each respective spray conduit to limit the spread of the spray area of each fuel jet by 80% or more;

advancing the fuel jet into a combustion chamber in the engine; and

the fuel jet is compression ignited in the combustion chamber.

7. The method of claim 6, wherein the diameter of the spray conduit outlet is 14 times or greater than the spray orifice.

8. The method of claim 7, wherein:

the diameter of the spray conduit outlet is 14.5 times or more greater than the spray orifice; and is also provided with

The spray orifice has a diameter of 0.09 mm to 0.35 mm and the spray conduit outlet has a diameter of 1.3 mm to 4.0 mm.

9. The method of any one of claims 6-8, wherein impinging each of the jets comprises impinging the jet to limit spread of the spray area by 85% or more.

10. The method of any one of claims 6-8, wherein:

each of the plurality of spray pipes is spaced a first distance from a respective one of the plurality of spray orifices, and each respective pipe outlet is spaced a pipe length distance from the pipe inlet that is different than the first distance; and is also provided with

The separation distance of each duct outlet is defined as the sum of the first distance and the duct length distance, and the separation distance is 10 millimeters to 30 millimeters.

11. An internal combustion engine system comprising:

an internal combustion engine having a combustion cylinder formed therein;

a fuel injector including a plurality of spray orifices formed therein, and a plurality of spray conduits each aligned with one of the plurality of spray orifices;

each of the plurality of spray orifices defining a spray orifice diameter dimension (d);

each of the plurality of spray conduits includes a conduit outlet, each conduit outlet defining a conduit discharge outlet diameter dimension (D) and being positioned at a spaced distance from a corresponding one of the plurality of spray apertures;

a relative Spray Area Reduction (SAR) of each of the plurality of spray pipes is based on D, D and the separation distance; and is also provided with

The SAR is about 80% or greater.

12. The engine system of claim 11, wherein the SAR is 85% or greater.

13. The engine system of claim 11 or 12, wherein the spray conduit outlet has a diameter that is 14 times or greater than the spray orifice.

14. The engine system of any of claims 11-13, wherein the internal combustion engine includes a piston movable within the cylinder to increase pressure in the cylinder to an auto-ignition threshold.

15. The engine system of claim 14, wherein:

d is about 0.09 millimeters to about 0.35 millimeters, and D is 1.3 millimeters to about 4.0 millimeters; and is also provided with

The separation distance is about 10 millimeters to about 30 millimeters.