WO2022243685A1

WO2022243685A1 - Fluid introduction system and method

Info

Publication number: WO2022243685A1
Application number: PCT/GB2022/051260
Authority: WO
Inventors: Martin Craig TURNER; Stuart David WHITEHEAD
Original assignee: Diffusion Technologies Limited
Priority date: 2021-05-21
Filing date: 2022-05-19
Publication date: 2022-11-24
Also published as: GB202107315D0; GB2606773A

Abstract

According to the present invention there is provided a fluid introduction system for enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine intake defining a flow path, the vehicle comprising a chamber for holding a fluid, the fluid introduction system comprising: a supply mechanism, connected to the chamber, comprising an outlet arrangement for introducing a supply of fluid into the engine intake, the outlet arrangement arranged to introduce a supply of fluid into the engine intake across the engine intake flow path. The outlet arrangement may comprise, or be, a plurality of outlets.

Description

FLUID INTRODUCTION SYSTEM AND METHOD

[0001] The present disclosure relates to a fluid introduction system for enhancing the combustion atmosphere in an internal combustion engine. The present disclosure also relates to a vehicle comprising a fluid introduction system. The present disclosure also relates to a method of enhancing the combustion atmosphere in an internal combustion engine.

BACKGROUND

[0002] An internal combustion engine requires a supply of fuel and oxygen with which to combust the fuel. Internal combustion engines comprise an intake system, typically an air intake system, by which an oxygenated air supply is provided to the engine for use in combustion. The combustion of the fuel takes place within a combustion chamber to produce power which is output by the engine.

[0003] Enhancing the combustion atmosphere in the engine is an important consideration in the field. It is desirable to enhance the combustion atmosphere in the engine by ensuring that conditions for the combustion of fuel are optimised in the engine.

[0004] It is known in the art to deliver a gaseous element to an internal combustion engine by means of fluidic injection. Whilst these conventional injection systems are well suited where the gaseous element is to be used as a fuel, they are not well suited in cases where the gas is to be used to enhance the air supply. Injector systems provide, or are controlled to provide, a non-continuous supply of gas (that is, a gas supply which is intermittently at a zero flowrate). For example, such systems operate using a square wave driving and implementation profile.

[0005] Furthermore, in known gas injection systems, gas is injected into the engine to mix with the air supply. It is important that the injected gas is well mixed with the air supply. Despite this, poor mixing of the injected gas with the air supply is achieved using conventional systems, for example using one or more injectors located linearly along just one side of an intake.

[0006] It is an object of the present invention to provide an improved system and/or method thereof and/or address one or more of the problems discussed above, or discussed elsewhere, or to at least provide an alternative system and/or method.

SUMMARY OF THE INVENTION

[0007] According to the present invention there is provided a fluid introduction system and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows. [0008] According to a first aspect of the present invention there is provided a fluid introduction system for enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine air intake, the vehicle comprising a chamber for holding a fluid and a supply mechanism for supplying the fluid into the engine air intake, the supply mechanism being connected to the chamber and configured to provide a continuous supply of fluid at a variable flow rate, the system comprising: a controller arranged to: receive an indication of an operating condition of the ICE; and control the supply mechanism to introduce a continuous supply of fluid into the engine air intake based on the operating condition of the ICE.

[0009] In this way, it is ensured that there is a continuous supply of fluid, for enhancing the combustion atmosphere, into the airflow in the engine intake. As such, the airflow into the combustion chamber always contains a supply of gas, even if only at a low concentration. This has been found to improve engine performance. Moreover, providing a continuous (i.e. without stopping) supply whilst being configured to provide a variable flow rate ensures maximum flexibility and adaptability of the fluid introduction system for all operating conditions of the ICE. Enhancement of the combustion atmosphere is based on the operating condition of the ICE, ensuring optimal performance. Significantly, such a construction can lead to an improved homogeneity of mixture of fluid and air arriving in the combustion chamber. In this way, reactions during combustion in the combustion chamber occur homogenously in the chamber, thereby improving engine performance. This is, for example, in contrast with a non-continuous supply (for example, a square wave profile between a zero and non-zero value) which would lead to less or non-homogeneous distribution.

[0010] In one example, the controller is arranged to: determine a fluid/air concentration based on the indication of the operating condition of the ICE; and control the supply mechanism to introduce a continuous supply of fluid into the engine air intake based on the determined fluid/air concentration. In this way, the combustion atmosphere can be enhanced by providing a determined fluid/air concentration, which may be the optimal fluid/air concentration for the operating condition of the ICE. In this way, improved engine performance is realised. Basing the control of the supply mechanism on the determined fluid/air concentration advantageously ensures optimal supply of fluid into the engine intake.

[0011] In one example, the controller is arranged to: receive an indication of a change in an operating condition of the ICE; control the supply mechanism to vary the supply of fluid to the engine intake based on the change. In this way, the system is able to change and adapt to changes in the operating condition of the ICE. The supply mechanism is similarly controllable to adjust to the change and continue to ensure improved engine performance.

[0012] In one example, the continuous supply is a supply of fluid at a non-zero flow rate. That is, continuous supply is a supply of fluid without stopping. In this way, a mixture of fluid and air is continuously provided, which ensures that the combustion atmosphere (i.e. the conditions at which combustion takes place in the chamber) is always enhanced.

[0013] In one example, the supply mechanism is configured to provide a variable flow rate that is one or more, or a combination of: at a first non-zero flow rate and moved to a second non-zero flow rate over a time period; and/or at a first non-zero flow rate and moved to a second non-zero flow rate over a time period, where the second flow rate is less than a maximum flow rate; and/or varied according to a profile other than a square wave, for example: a curve profile; a parabolic profile; a ramped-up profile; a ramped-down profile; a sinusoidal profile; and/or saw-toothed profile. In this way, the system is well suited to many driving situations and changes in operating condition. That is, the supply of fluid does not need to remain at a steady state and may vary in supply as required by the situation. Or, if a steady state is required, this can be maintained at a level that is not zero, and not a maximum, but is at a level that is between these extremes. In both examples, greater control is achieved, and greater efficiency is the result. Additionally, the supply profiles provided are particularly suited to the operation of large goods vehicles (LGV) or heavy goods vehicle (HGV), for example lorries and refuse trucks. The varying of the fluid supply may be in a smooth or gradual manner. Homogeneity of the fluid/air mixture may be advantageously improved or achieved by smooth or gradual variation of the fluid supply. Homogeneity of the fluid/air mixture may also advantageously be improved by or result from maintaining the supply of fluid at a constant or steady level or flow rate.

[0014] In one example, the supply mechanism comprises one or more flow control components, and the controller is arranged to: control the one or more flow control components to each provide a continuous supply of fluid. In this way, the flow control components provide a continuous fluid supply, which ensures the constant fluid/air mixture resulting in the advantages as herein described. This is in contrast to component that can only be controlled to be fully open, or fully closed - i.e. controlled to have a zero-to-maximum square wave control or output profile.

[0015] In one example, the one or more flow control components are openable at and between a minimal and a maximal opening functionality, and the controller is arranged to control the one or more flow control components to remain open between the minimal and maximal opening functionality. In this way, flow rate of the fluid supply is more adjustable, providing control over the fluid/air mixture and/or concentration.

[0016] In one example, the fluid is one or more of: hydrogen gas; LPG; butane; propane; HHO; liquified natural gas (LNG); compressed natural gas (CNG). Such gases are highly suited to enhancing the engine combustion atmosphere.

[0017] In one example, the supply mechanism comprises an outlet arrangement for introducing a supply of fluid into the engine air intake, the engine intake defining a flow path, wherein the outlet arrangement is arranged to introduce a supply of fluid into the engine intake across the engine intake flow path. Such a construction is highly advantageous. Introducing the supply of fluid across the engine intake provides for improved mixing of the fluid and air, which ensures that the combustion atmosphere in the combustion chamber is enhanced. In one example, the outlet arrangement comprises a plurality of outlets. In one example, the outlet arrangement is a plurality of outlets. That is, the outlet arrangement may comprise, or be, multiple outlets. The outlets may be distinct, discrete and/or separated from one another. Advantageously, a plurality of outlets may be well suited to high- pressure introduction of fluid into the engine intake. Furthermore, a plurality of outlets may improve control of direction or amount of the introduction of fluid supply. In another example, the outlet arrangement comprises, or is, a single outlet. The single outlet may be a slit. The slit may be otherwise referred to as a slot. The slit may simplify manufacture, as it requires fewer manufacturing operations. Furthermore, the slit may be well suited to rapid introduction of a high volume of fluid into the engine intake.

[0018] In one example, the fluid/air concentration (e.g. the % of fluid in a fluid-air mix) is in the region of greater than 0% and less than or equal to 6%, and typically 1 - 6%. The fluid/air concentration may be in the region of 1 - 6% when the ICE 200 is demanding a fluid supply, preferably 1 - 5%, 2 - 5% or 3 - 5%, and in some examples, where a supply of hydrogen is provided, in the region of 2 - 3%. It will be understood that when the ICE 200 is not demanding a fluid supply, the concentration may be 0%.

[0019] In one example, the operating condition is one or more of: engine power demand; engine load; fuel flow rate; acceleration; desired vehicle speed; current vehicle speed; engine temperature, for example temperature in the combustion chamber; engine oxygen levels; gearbox readings; throttle position.

[0020] According to a second aspect of the present invention there is provided a vehicle comprising a fluid introduction system according to the first aspect of the present invention.

[0021] According to a third aspect of the present invention there is provided a method of enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine air intake, the vehicle comprising a chamber for holding a fluid and a supply mechanism for supplying the fluid into the engine air intake, the supply mechanism being connected to the chamber and configured to provide a continuous supply of fluid at a variable flow rate, the method comprising: receiving an indication of an operating condition of the ICE; controlling the supply mechanism to introduce a continuous supply of fluid into the engine air intake based on the operating condition of the ICE.

[0022] In one example, the method comprises the steps of: determining a fluid/air concentration based on the indication of the operating condition of the ICE; and controlling the supply mechanism to introduce a continuous supply of fluid into the engine air intake based on the determined fluid/air concentration.

[0023] According to a fourth aspect of the present invention there is provided a fluid introduction system for enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine intake defining a flow path, the vehicle comprising a chamber for holding a fluid, the fluid introduction system comprising: a supply mechanism, connected to the chamber, comprising an outlet arrangement for introducing a supply of fluid into the engine intake, the outlet arrangement arranged to introduce a supply of fluid into the engine intake across the engine intake flow path.

[0024] Such a construction is highly advantageous. Introducing the supply of fluid across the engine intake provides for improved mixing of the fluid and air, which ensures that the combustion atmosphere in the combustion chamber is enhanced. “Across” means that the introduction is not solely along an intake, for example. Significantly, such a construction can lead to an improved homogeneity of mixture of fluid and air arriving in the combustion chamber. In this way, reactions during combustion in the combustion chamber occur homogenously in the chamber, thereby improving engine performance. This is, for example, in contrast with a non-continuous supply (for example, a square wave profile between a zero and non-zero value) which would lead to less or non- homogeneous distribution.

[0025] In one example, the outlet arrangement comprises a plurality of outlets. In one example, the outlet arrangement is a plurality of outlets. That is, the outlet arrangement may comprise, or be, multiple outlets. The outlets may be distinct, discrete and/or separated from one another. Advantageously, a plurality of outlets may be well suited to high-pressure introduction of fluid into the engine intake. Furthermore, a plurality of outlets may improve control of direction or amount of the introduction of fluid supply. In another example, the outlet arrangement comprises, or is, a single outlet. The single outlet may be a slit. The slit may be otherwise referred to as a slot. The slit may simplify manufacture, as it requires fewer manufacturing operations. Furthermore, the slit may be well suited to rapid introduction of a high volume of fluid into the engine intake.

[0026] In one example, there is provided a fluid introduction system for enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine intake defining a flow path, the vehicle comprising a chamber for holding a fluid, the fluid introduction system comprising: a supply mechanism, connected to the chamber, comprising a plurality of outlets for introducing a supply of fluid into the engine intake, the plurality of outlets arranged to introduce a supply of fluid into the engine intake across the engine intake flow path.

[0027] In one example, the outlet arrangement is arranged across the engine intake flow path. Arranging the outlet arrangement across the flow path provides a simple and robust arrangement for introducing the fluid across the flow path, which leads to improved mixing. In one example, the outlets are arranged across the engine intake flow path. That is, the outlets of the plurality of outlets may be arranged across the engine intake flow path. Arranging the outlets across the flow path provides a simple and robust arrangement for introducing the fluid across the flow path, which leads to improved mixing.

[0028] In one example, the outlet arrangement is laterally, circumferentially and/or helically arranged across the engine intake flow path. Such arrangements have been found to be highly advantageous in improving mixing of the fluid and air. In one example, the outlet arrangement comprises a plurality of outlets, and the outlets are laterally, circumferentially and/or helically arranged across the engine intake flow path. In one example, the outlets are laterally, circumferentially and/or helically arranged across the engine intake flow path. That is, the outlets of the plurality of outlets may be arranged across the engine intake flow path. Such arrangements have been found to be highly advantageous in improving mixing of the fluid and air.

[0029] In one example, the supply mechanism comprises: a spray bar comprising the outlet arrangement, the spray bar extending through the engine intake. Such a construction is a simple and robust manner in which to introduce fluid into the engine intake. In one example, the supply mechanism comprises: a spray bar comprising the plurality of outlets, the spray bar extending through the engine intake. Such a construction is a simple and robust manner in which to introduce fluid into the engine intake.

[0030] In one example, the outlet arrangement of the spray bar extends across the engine intake flow path. In this way, fluid supply from the spray bar outlet arrangement mixes with the air through the intake in an improved manner. In one example, the outlets of the spray bar extend across the engine intake flow path. In this way, fluid supply from the spray bar outlets mixes with the air through the intake in an improved manner.

[0031] In one example, the spray bar comprises end regions devoid of the outlet arrangement, and the spray bar is connected to the walls of the engine intake at the end regions. A secure connection in the engine, and to the engine intake, is thereby made. In one example, the spray bar comprises end regions devoid of outlets, and the spray bar is connected to the walls of the engine intake at the end regions. A secure connection in the engine, and to the engine intake, is thereby made.

[0032] In one example, the chamber is connected to the spray bar at both end regions to provide a supply of fluid at both ends. In this way, fluid can be forced into the engine intake by the system. Also, fluid introduction is more uniform, compared with being dominant at one end of the bar. Improved control over flow rate and supply is thereby provided.

[0033] In one example, the spray bar comprises an outlet arrangement comprising a plurality of laterally aligned outlets. Such an arrangement provides a supply of gas in an improved manner. Laterally aligned outlets facilitate construction of said outlets, and provision in the engine intake, in an improved manner. This might also allow for greater control consistency, in terms of the direction of introduction of the fluid. In one example, the spray bar comprises a plurality of laterally aligned outlets. Such an arrangement provides a supply of gas in an improved manner. Laterally aligned outlets facilitate construction of said outlets, and provision in the engine intake, in an improved manner. This might also allow for greater control consistency, in terms of the direction of introduction of the fluid.

[0034] In one example, the orientation of the outlet arrangement is adjustable to adjust the direction of the supply of fluid relative to the engine intake flow path. In one example, the orientations of the outlets are adjustable to adjust the direction of the supply of fluid relative to the engine intake flow path. In this way, the outlets may be oriented depending on the operating condition, required supply of fluid, type of fluid being supplied, or other variables. The system can thereby be adapted depending on the operating situation. This could be during an installation of a system, or during operation of a system. Installation adjustment may be suited to particular expected fuel or fluid types in use. The adjustment may therefore improve manufacturing efficiencies - one system can be used in different ways. Adjustment in use may allow for greater control, in use, of the ICE.

[0035] In one example, the supply mechanism comprises an adjustment element external to the engine intake, the adjustment element operable to adjust a direction of the supply of fluid. In this way, the supply mechanism can be adjusted without dismantling the system and without substantial disruption. The supply mechanism is thereby readily adjustable dependent on intended or live use.

[0036] In one example, the supply mechanism is oriented or adjustable to provide a supply of fluid from the outlet arrangement against the engine intake flow path. In one example, the supply mechanism is oriented or adjustable to provide a supply of fluid from the outlets against the engine intake flow path. Such an arrangement helps to regulate and control the supply of fluid. This could also help with more efficient or effective mixing.

[0037] In one example, the supply mechanism is oriented or adjustable to provide a supply of fluid from the outlet arrangement perpendicular to the engine intake flow path. In one example, the supply mechanism is oriented or adjustable to provide a supply of fluid from the outlets perpendicular to the engine intake flow path. Such an arrangement helps to regulate and control the supply of fluid. This could also help with more efficient or effective mixing.

[0038] In one example, the supply mechanism is configured to provide a continuous supply of fluid at a variable flow rate, the system comprising: a controller arranged to: receive an indication of an operating condition of the ICE; control the supply mechanism to introduce a continuous supply of fluid into the engine intake based the operating condition of the ICE. In this way, it is ensured that there is a continuous supply of fluid, for enhancing the combustion atmosphere, into the airflow in the engine intake. As such, the airflow into the combustion chamber always contains a supply of gas, even if only at a low concentration. This has been found to improve engine performance. Moreover, providing a continuous (i.e. without stopping) supply whilst being configured to provide a variable flow rate ensures maximum flexibility and adaptability of the fluid introduction system for all operating conditions of the ICE. Enhancement of the combustion atmosphere is based on the operating condition of the ICE, ensuring optimal performance.

[0039] According to a fifth aspect of the present invention there is provided a vehicle comprising a fluid introduction system According to the fourth aspect of the present invention.

[0040] According to a sixth aspect of the present invention there is provided a method of enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine intake defining a flow path, the vehicle comprising a chamber for holding a fluid, the method comprising the steps of: providing a supply mechanism comprising an outlet arrangement for introducing a supply of fluid into the engine intake; and arranging the outlet arrangement to introduce a supply of fluid into the engine intake across the engine intake flow path.

[0041] In one example, the outlet arrangement is a plurality of outlets. That is, the outlet arrangement may comprise multiple outlets. The outlets may be distinct, discrete and/or separated from one another. Advantageously, this a plurality of outlets may be well suited to high-pressure introduction of fluid into the engine intake. Furthermore, a plurality of outlets may improve control of direction or amount of the introduction of fluid supply. In another example, the outlet arrangement comprises a single outlet. The single outlet may be a slit. The slit may be otherwise referred to as a slot. The slit may simplify manufacture, as it requires fewer manufacturing operations. Furthermore, the slit may be well suited to rapid introduction of a high volume of fluid into the engine intake.

[0042] In one example, there is provided a method of enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine intake defining a flow path, the vehicle comprising a chamber for holding a fluid, the method comprising the steps of: providing a supply mechanism comprising a plurality of outlets for introducing a supply of fluid into the engine intake; and arranging the outlets to introduce a supply of fluid into the engine intake across the engine intake flow path.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example only, to the accompanying diagrammatic drawings in which:

Fig. 1 shows a schematic of a vehicle, ICE, and fluid introduction system;

Fig. 2 shows a fluid introduction system; Fig. 3 shows a side cross-sectional view of a region of the system of Fig. 2; Fig. 4 shows a spray bar of a fluid introduction system;

Fig. 5 shows square wave pulse profiles for a prior art injector system;

Fig. 6 shows a waveform illustrating gas supply versus time;

Fig. 7 shows a waveform illustrating gas supply versus time;

Fig. 8 shows a waveform illustrating gas supply versus time;

Fig. 9 shows general methodology principles; and Fig. 10 shows general methodology principles.

DETAILED DESCRIPTION

[0044] Referring to Figures 1 - 4, a vehicle 10, fluid introduction system 100 and internal combustion engine (ICE) 200 according to an embodiment of the present invention are schematically shown. The fluid introduction system 100 is for enhancing the combustion atmosphere in the ICE 200 of the vehicle 10.

[0045] The ICE 200 comprises an engine air intake. The engine air intake is a system through which air is admitted to the engine via ducting or piping or some other conduit.

[0046] The vehicle 10 comprises a chamber 120 for holding a fluid. In this exemplary embodiment, the fluid is Liquified Petroleum Gas (LPG). The fluid might typically be, or be released as, a gas, but could take the form of a mist or aerosol. The vehicle 10 further comprises a supply mechanism 140 for supplying the fluid into the engine intake. The supply mechanism 140 is connected (that is, fluidically connected, via ducting of piping) to the chamber 120.

[0047] As will be explained in further detail herein, the supply mechanism 140 is configured to provide a continuous supply of fluid at a variable flow rate.

[0048] The fluid introduction system 100 comprises a controller 110 arranged to receive an indication of an operating condition of the ICE 200. In response to receiving the indication of the operating condition of the ICE 200, the controller 110 is arranged to control the supply mechanism 140 to introduce a continuous supply of fluid into the engine intake based on the operating condition of the ICE 200.

[0049] Referring to Figure 2, the supply mechanism 140 comprises a regulator 160, a filter 170, a gas sensor 180, and an injector block 190. The injector block 190 comprises one or more flow control components (e.g. actuators). The controller is arranged to control the one or more flow control components to each provide a continuous supply of gas. Figure 2 further illustrates the engine intake 210 and the fluidic connection 150 between the chamber 120 and the supply mechanism 140.

[0050] The supply mechanism further comprises a spray bar 1000 comprising an outlet arrangement. In this example, the outlet arrangement is a plurality of outlets 1100 for introducing a supply of fluid into the engine intake 210. As shown in Figure 3, the engine intake 210 defines an air flow path 215 (and also direction) through the engine intake 210. The outlets 1100 of the spray bar 1000 are arranged to introduce a supply of fluid into the engine intake 210 across the engine intake flow path 215. In this exemplary embodiment, the outlets have a fixed outlet functionality (i.e. outlet dimension). In another exemplary embodiment, the outlets are openable at a minimal and a maximal outlet functionality (i.e. outlet dimension, which may be a diameter or “extent”), and the controller 110 is arranged to control the one or more actuators to open the outlets between the minimal and maximal outlet functionality. More generally, flow control components may be used to control the flow as described herein, and these could be actuators of some kind, actuators connected to outlets, or outlets. Functionally, is it the control that is important, and this can be achieved using different types of apparatus.

[0051] In another example, the supply mechanism comprises a spray bar 1000 comprising an outlet arrangement in the form of a slit or slot (not shown). The slit or slot is for introducing a supply of fluid into the engine intake 210. That is, rather than a plurality of outlets (or possibly in addition to the plurality of outlets), the outlet arrangement comprises a single outlet in the form of an elongate or continuous slit. The slit of the spray bar 1000 is arranged to introduce a supply of fluid into the engine intake 210 across the engine intake flow path 215. The slit or slot may have a fixed outlet functionality (i.e. slit dimension). In another example, the slit is openable at a minimal and a maximal outlet functionality (i.e. slit dimension, which may be a width, length, or “extent”), and the controller 110 is arranged to control the one or more actuators to open the slit between the minimal and maximal outlet functionality. More generally, flow control components may be used to control the flow as described herein, and these could be actuators of some kind, actuators connected to the slit. Functionally, is it the control that is important, and this can be achieved using different types of apparatus.

[0052] As mentioned above, the controller 110 is arranged to receive an indication of an operating condition of the ICE 200. The indication of the operating condition of the ICE 200 are provided by operating condition sensors provided at the ICE 200. The operating condition sensors are arranged to sense: engine power demand; engine load; fuel flow rate; acceleration; desired vehicle speed; current vehicle speed; engine temperature, for example temperature in the combustion chamber; engine oxygen levels; gearbox readings; throttle position. The controller 110 is arranged to control the supply mechanism 140 to introduce a continuous supply of fluid into the engine intake 210 based on the operating condition of the ICE 200 sensed by the operating condition sensors. [0053] In controlling the supply mechanism 140, the controller 110 is arranged to receive or even determine a fluid/air concentration based on the indication of the operating condition of the ICE 200. The fluid-air concentration determined is a fluid air concentration suitable to enhance the combustion atmosphere in the ICE 200. A suitable fluid-air concentration can be determined by reference to lookup tables or data stored in a memory. The controller 110 is able to access the memory, and thereby determine the suitable fluid/air concentration. Following determining the fluid/air concentration, the controller 110 controls the supply mechanism 140 to introduce a continuous supply of fluid into the engine intake 210 based on the determined fluid/air concentration. That is, the controller 110 controls the supply mechanism 140 to introduce a continuous supply in order to achieve the determined fluid/air concentration in the engine intake 210 and/or the combustion chamber of the ICE 200. Whilst the fluid/air concentration depends on the operating condition, it is typically in the region of 1 - 6% fluid when the ICE 200 is demanding a fluid supply, preferably 1 - 5%, 2 - 5% or 3 - 5%, and in some examples, where a supply of hydrogen is provided, in the region of 2 - 3%. It will be understood that when the ICE 200 is not demanding a fluid supply, the concentration may be 0%.

[0054] During operation of the ICE 200, the operating conditions of the ICE 200 are subject to change, for example when increased power is demanded of the engine. The controller 110 is arranged to receive an indication of such a change in operating condition of the ICE 200. Following this, the controller 110 is arranged to control the supply mechanism 140 to vary the supply of fluid to the engine intake 210 based on the change. For example, if increased power is demanded of the engine, the controller 110 is arranged to control the supply mechanism 140 to increase the supply of fluid to the engine intake 210. In this exemplary embodiment, the controller 110 determines a fluid-air concentration suitable to enhance the combustion atmosphere based on the increased power demanded of the engine, and controls the supply mechanism 140 to provide the fluid to the engine intake 210. In this way, the conditions in the engine combustion chamber can be enhanced so that the increased power can be provided. Conversely, where reduced power is required of the engine, the controller 110 is arranged to control the supply mechanism 140 to decrease the supply of fluid to the engine intake 210.

[0055] The skilled person will appreciate that in rudimentary embodiments, the controller 110 may not need to determine the fluid/air concentration, and may instead simply increase the flow rate of the supply of gas in response to the increased power demand (for example, increasing proportionally to the power demand), thereby to enhance the combustion atmosphere.

[0056] In the prior art, LPG gas is injected into the engine intake of a vehicle. Injecting the gas into the engine intake is performed by an injector injecting bursts or pulses of gas at a fixed frequency, from zero to a maximum level. That is, in a binary or square wave manner. The amount of gas introduced into the engine intake is controlled by varying the length of the injector pulse. In each burst or pulse period there is a first time period in which the injector is “open”, and thus providing a supply of gas, and a second time period in which the injector is “closed”, and thus not providing a supply of gas (i.e. there is a zero flow rate).

[0057] Referring to Figure 5, two pulse profiles for a prior art injector system are shown. In Figure 5(a), the injector is pulsed according to a 50% pulse width, meaning that the injector has equal open and closed durations. In Figure 5(b), the injector is pulsed according to a 12.5% pulse width, meaning that the injector is open for only a quarter of the period of which the 50% pulse width system is open.

[0058] Pulse profiles such as those shown in Figures 5(a) and 5(b), which may be referred to as “square-wave” profiles, result in a non-continuous supply of gas into the engine intake. A “non- continuous” supply is a supply where there are time periods in which no gas is supplied. Such is the case in the prior art injector system. Conversely, a “continuous” supply is a supply where there are no time periods in which no gas is supplied, in a desired supply period; that is, gas is supplied without stopping or interruption, even if the supply is at a low level. That is, a continuous supply is one which is always at a non-zero flow rate, in a desired supply period.

[0059] By controlling the pulse width, the amount or concentration of the gas injected into the engine intake is somewhat controllable. However, during operation of the prior art injector system, in a desired supply period, there are time periods in which no gas is injected into the engine intake. As a result, during operation of the internal combustion engine, as air flows through the engine intake, there are time periods in which no gas is present in the airflow through the engine intake. It will also be understood by the person skilled in the art of injector systems that conventional gas injection is “non-variable”. That is, gas output is either “on” or “off’, with no graduation or variation in between. Such output is sometimes known as a binary output. It will be appreciated that edge behaviour (for example, any slight graduation between the “off flow rate and “on” flow rate) are discounted, as such behaviour is not sufficient for injector systems to be understood to provide a supply of gas that is variable or graduated in its flow rate. In other words, the supply of gas is not, and cannot be, maintained at a level in between minimum and maximum levels.

[0060] Considering the present invention, Figures 6 - 8 show graphs of gas supply G (y-axis) versus time t (x-axis), where the supply is continuous in each case. In this example, G is the gas flow rate. In the present invention, the supply mechanism 140 is configured to provide a continuous supply of fluid at a variable flow rate. The controller 110 is arranged to control the supply mechanism 140 to introduce a continuous supply of fluid into the engine intake 210.

[0061] In Figure 6, a continuous (i.e. without falling to zero), yet non-varying (i.e. constant) supply of gas is introduced into the engine intake 210. This is graphically represented by a constant gas supply level versus time. A constant supply of gas is provided where the operating condition is a constant power or speed. [0062] In Figure 7, a continuous and variable supply of gas is introduced into the engine intake. This is graphically represented by a non-zero, variable gas supply level versus time, in this example varying according to a sawtooth profile. A continuous yet variable supply of gas is provided where the operating condition is a varying power or speed over time. One example of where this operating profile would be employed or observed is in a refuse truck, which accelerates rapidly up to speed, before rapidly decelerating to low or zero speed.

[0063] In Figure 8, a continuous, variable, supply of gas is introduced into the engine intake 210 over a first time period t1, followed by a continuous, non-variable, supply of gas over a second time period t2. This is graphically represented by an increasing gas supply level versus time for the first time period t1 , followed by a constant gas supply level versus time for the second time period t2. Such a gas supply profile is employed where a vehicle accelerates up to a speed v over a first time period t1 and then maintains a constant speed v over a second time period t2. This gas supply profile is provided by a supply mechanism configured to provide a variable flow rate that is at a first non-zero flow rate and moved to a second non-zero flow rate over a time period, and varied according to a ramped-up profile. Subsequent to this, the gas supply is maintained at a constant level. One example of where this operating profile would be employed or observed is in a vehicle having a constant load on the engine, such as a vehicle travelling on a level road maintaining a constant velocity.

[0064] For the avoidance of doubt, the operating condition may be a past condition, for example a condition in the immediate past, such as a condition recently sensed and provided to the controller 110. The operating condition may additionally or alternatively be a present condition, for example an estimated current power requirement based on acceleration profile; power profiles; or the like. In further embodiments, the operating condition is a future condition. This may be employed in autonomous vehicles, where future road terrain is known to the controller 110 and the operating condition may be a demand for an increase in power due to an uphill gradient.

[0065] Referring to Figure 9, a method of enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle is shown. The ICE comprises an engine intake, the vehicle comprising a chamber for holding a fluid and a supply mechanism for supplying the fluid into the engine intake, the supply mechanism being connected to the chamber and configured to provide a continuous supply of fluid at a variable flow rate. Step S900 comprises receiving an indication of an operating condition of the ICE. Step S910 comprises controlling the supply mechanism to introduce a continuous supply of gas into the engine intake based on the operating condition of the ICE.

[0066] Referring back to Figures 1 - 4, and as introduced above, a fluid introduction system 100 according to an embodiment of the present invention is shown. The fluid introduction system 100 is for enhancing the combustion atmosphere in an internal combustion engine (ICE) 200 of a vehicle 10. The ICE 200 comprises an engine intake 210 defining an engine intake flow path 215. The vehicle 200 comprises a chamber 120 for holding a fluid. The fluid introduction system 100 is provided upstream of a turbocharger and combustion chamber but is downstream of engine vacuum take-offs.

[0067] The fluid introduction system 100 comprises a supply mechanism 110 connected to the chamber 120. The supply mechanism 110 comprises the regulator 160, filter 170, gas sensor 180, and the injector block 190. The fluid introduction system 100 comprises an outlet arrangement. In this example, the outlet arrangement is a plurality of outlets 1100 for introducing a supply of fluid into the engine intake 210. The outlets 1100 are arranged to introduce a supply of fluid into the engine intake 210 across the engine intake flow path 215.

[0068] In another example, the fluid introduction system 100 comprises an outlet arrangement in the form of a slit or slot (not shown). The slit or slot is for introducing a supply of fluid into the engine intake 210. That is, rather than a plurality of outlets (or possibly in addition to the plurality of outlets), the outlet arrangement comprises a single outlet in the form of an elongate or continuous slit. The slit of the spray bar 1000 is arranged to introduce a supply of fluid into the engine intake 210 across the engine intake flow path 215.

[0069] In prior art injector systems (which as explained above are different systems to fluid introduction systems according to the invention, as injector systems are non-continuous), an outlet arrangement (e.g., a plurality of outlets) is arranged to introduce fluid supply along the engine intake flow path, rather than across it. That is, in the prior art, outlets are arranged linearly along the intake. However, in the present invention, the outlet arrangement (e.g., a plurality of outlets) is arranged across the engine intake flow path 215. Whilst this distinction is subtle, it is powerful and highly advantageous as it leads to considerably improved mixing of the supply of gas with the air passing through the engine intake 210 along the flow path 215.

[0070] As best shown in Figure 4, the outlets 1100 are arranged across the engine intake flow path 215. When a supply of gas is introduced into the engine intake 210 through the outlets 1100, improved mixing with the airflow is achieved due to the arrangement of the outlets 1100. In the exemplary embodiment illustrated, the outlets are laterally aligned (i.e. in a side-by-side manner) across the engine intake flow path, and are provided in a spray bar 1000. In other exemplary embodiments, the outlets can be circumferentially arranged (i.e. about the engine intake, for example provided in the walls of the engine intake to provide a gas supply thereto, or in a collar or annular component in or forming part of the intake), and/or helically arranged (i.e. helically about the engine intake, again provided in the walls of the engine intake to provide a gas supply thereto).

[0071] The spray bar 1000 extends through the engine intake 210 across the engine intake flow path 215. The spray bar 1000 comprises end regions 212a, 212b and is rotatably connected to the walls of the engine intake 210 at the end regions. In this way, the spray bar 1000 is configured to rotate in the engine intake 210, which allows the orientation of the outlets 210 relative to the airflow path 215 to be adjusted by the user, or by an electronic adjustment system controlled by the controller 110. An adjustment element, in the form of an adjustment lever 214, is attached to the spray bar 1000 to adjust the direction of the supply of fluid from outlets 1110 into the engine intake 210.

[0072] In a first orientation, the spray bar 1000 is oriented, by adjusting the adjustment lever 214, to provide the supply of fluid from the outlets 1100 in a direction which is against the engine intake flow path 215 (i.e. against a direction of air flow, in use). That is, the outlets 1100 open into the engine intake flow path 215 (i.e. against a direction of air flow, in use), as shown in Figure 4. In this way, a high-pressure region is created at the outlets 1000, which is particularly useful for certain types of fuel, particularly LPG, butane, liquified natural gas (LNG), compressed natural gas (CNG). In general, gas- air mixing is improved.

[0073] In a second orientation, the spray bar 1000 is oriented, by adjusting the adjustment lever 214, to provide the supply of fluid from the outlets in a direction which is perpendicular to the engine intake flow path 215. That is the outlets 1100 open perpendicularly to the flow path 215, such that air flows along the flow path 215 and over the outlets 1100 (where the outlets 1100 are provided on an upper side of the spray bar 1000), and/or under the outlets 1100 (where the outlets are provided on a lower side of the spray bar 1000). In this way, a low-pressure region is created at the outlets 1000, which is particularly useful for certain types of fuel, particularly hydrogen or HHO gas, as the low-pressure acts to assist in drawing the hydrogen gas from the outlets 1000. In general, gas-air mixing is improved.

[0074] In one exemplary embodiment, the supply mechanism 140 is configured to provide a continuous supply of fluid at a variable flow rate, as is consistent with the description above. Here, the fluid introduction system 100 comprises the controller 110, the controller 110 arranged to receive an indication of an operating condition of the ICE 200. Features of this embodiment are consistent with those described above, and description will not be repeated for purpose of conciseness.

[0075] Referring to Figure 10, a method of enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle is shown. The ICE comprises an engine intake defining a flow path. The vehicle comprises a chamber for holding a fluid. Step S1000 comprises providing a supply mechanism comprising an outlet arrangement for introducing a supply of fluid into the engine intake. Step S1100 comprises arranging the outlet arrangement to introduce a supply of fluid into the engine intake across the engine intake flow path. In one example, the outlet arrangement is a plurality of outlets.

[0076] It will be appreciated that the flow control discussed above could perhaps be applied to existing apparatus, for example by changing the way in which that apparatus is controlled. For example, the functionality could be applied in a retrofit manner. It will be appreciated that the introduction of fluid across an intake path could perhaps be applied to existing apparatus, for example by changing the way in which fluid is introduced in that apparatus. For example, the functionality could be applied in a retrofit manner. In either or both examples, the functionality could instead be provided in a new apparatus.

[0077] Although a few preferred embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

[0078] The preceding description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

[0079] The terms and words used in the preceding description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

[0080] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. The terms “front”, “rear”, “side”, “upper”, “lower”, “over”, “under”, “inner”, “outer” and like terms are used to refer to the apparatus and its components in the orientation in which it is illustrated, which is the orientation in which it is intended to be used but should not be taken as otherwise limiting. Like reference numerals are used to denote like features throughout the figures, which are not to scale.

[0081] At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as ‘component’, ‘module’ or ‘unit’ used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of others.

[0082] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0083] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0084] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0085] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1 . A fluid introduction system for enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine intake defining a flow path, the vehicle comprising a chamber for holding a fluid, the fluid introduction system comprising: a supply mechanism, connected to the chamber, comprising an outlet arrangement for introducing a supply of fluid into the engine intake, the outlet arrangement arranged to introduce a supply of fluid into the engine intake across the engine intake flow path.

2. A fluid introduction system as claimed in claim 1 wherein the outlet arrangement is arranged across the engine intake flow path.

3. A fluid introduction system as claimed in either of claims 1 or 2 wherein the outlet arrangement is laterally, circumferentially and/or helically arranged across the engine intake flow path.

4. A fluid introduction system as claimed in any previous claim wherein the supply mechanism comprises: a spray bar comprising the outlet arrangement, the spray bar extending through the engine intake.

5. A fluid introduction system as claimed in claim 4 wherein the outlet arrangement of the spray bar extends across the engine intake flow path.

6. A fluid introduction system as claimed in either of claims 4 or 5 wherein the spray bar comprises end regions devoid of the outlet arrangement, and the spray bar is connected to the walls of the engine intake at the end regions.

7. A fluid introduction system as claimed in claim 6 wherein the chamber is connected to the spray bar at both end regions to provide a supply of fluid at both ends.

8. A fluid introduction system as claimed in any of claims 4 to 7 wherein the spray bar comprises a outlet arrangement comprising a plurality of laterally aligned outlets.

9. A fluid introduction system as claimed in any previous claim wherein the orientation of the outlet arrangement is adjustable to adjust the direction of the supply of fluid relative to the engine intake flow path.

10. A fluid introduction system as claimed in any previous claim wherein the supply mechanism comprises an adjustment element external to the engine intake, the adjustment element operable to adjust a direction of the supply of fluid.

11 . A fluid introduction system as claimed in any previous claim wherein the supply mechanism is oriented or adjustable to provide a supply of fluid from the outlet arrangement against the engine intake flow path.

12. A fluid introduction system as claimed in any previous claim wherein the supply mechanism is oriented or adjustable to provide a supply of fluid from the outlet arrangement perpendicular to the engine intake flow path.

13. A fluid introduction system as claimed in any previous claim wherein the supply mechanism is configured to provide a continuous supply of fluid at a variable flow rate, the system comprising: a controller arranged to: receive an indication of an operating condition of the ICE; control the supply mechanism to introduce a continuous supply of fluid into the engine intake based the operating condition of the ICE.

14. A vehicle comprising a fluid introduction system as claimed in any previous claim.

15. A method of enhancing the combustion atmosphere in an internal combustion engine (ICE) of a vehicle, the ICE comprising an engine intake defining a flow path, the vehicle comprising a chamber for holding a fluid, the method comprising the steps of: providing a supply mechanism comprising an outlet arrangement for introducing a supply of fluid into the engine intake; and arranging the outlet arrangement to introduce a supply of fluid into the engine intake across the engine intake flow path.