INTAKE BYPASS FOR LIQUID FUEL ENGINE

Abstract

Fuel supply system (16) for an internal combustion engine (14), the fuel supply system (16) comprising: an air compressor (22); a compressed air supply passage (24) connected downstream of the air compressor (22); an air cooler (34) connected downstream of the air compressor (22) and the compressed air supply passage (24); a bypass passage (32) connected downstream of the air compressor (22); a fuel injector (26) attached to the bypass passage (32); and a valve (30) connected between the air compressor (22) and the air cooler (34), the valve (30) being designed to block an intake air flow to the air cooler (34), causing the intake air to flow to the bypass passage (32), or to allow the intake air to flow to the air cooler (34).

Description

Technical field

[0001] The present disclosure relates generally to methods and systems for intake systems of internal combustion engines and in particular to systems and methods for controlling the airflow or an air and fuel mixture to an internal combustion engine. State of the art

[0002] Internal combustion engine designs are becoming increasingly diverse, enabling the combustion of various types of fuels, either instead of or in addition to conventional fuels such as diesel or gasoline. Some of these engine systems burn liquid fuels. These non-traditional liquid fuel combustion systems (e.g., systems that store fuel in liquid form and / or supply one or more fuel injectors with liquid fuel) can produce a relatively low amount of soot during fuel combustion, utilize fuel from biogenic sources, or employ fuel produced using carbon dioxide captured from the atmosphere. Internal combustion engines designed to use so-called "alternative" fuels can burn liquid-stored fuels with a high alcohol content (e.g., more than 50%), such as methanol or ethanol.The alternative fuel can be burned alone or in combination with another fuel, such as diesel, to create a pilot flame. Generally, greater environmental benefits can be achieved by replacing increasing amounts of conventional fuels, such as diesel, with an alternative fuel.

[0003] Although alternative fuels like methanol and ethanol offer advantages, such as reduced environmental impact, their use also presents challenges. Methanol, for example, has a lower energy density and evaporates more slowly than diesel fuel, which is problematic because complete vaporization is desirable for combustion. Due to methanol's relatively lower energy density, a larger quantity of this fuel must be injected to produce the same amount of energy as diesel fuel. This, in turn, further slows the vaporization of the injected methanol. These problems can be exacerbated if the air supplied to the combustion engine is relatively cold.

[0004] A methanol engine is described in CN 214366438 U to Zhang (“the '438 patent”). The methanol engine in the '438 patent includes an air intake bypass tube and a three-way valve that controls whether air is supplied to a cooler. The position of the three-way valve is adjusted in response to the temperature of the intake air. Although the methanol engine described in the '438 patent may be useful for systems where methanol is injected directly into a plenum of an intake manifold, it may not be able to ensure that this methanol completely vaporizes, or it may require other trade-offs that negatively affect the engine's operation in order to allow the injected fuel to vaporize.

[0005] The systems and methods of this disclosure can solve one or more of the problems listed above and / or other prior art problems. However, the scope of this disclosure is defined by the attached claims, and not by the ability to solve any specific problem. Brief description

[0006] In one aspect, a fuel supply system for an internal combustion engine can include an air compressor, an air cooler connected downstream of the air compressor and the compressed air supply port, and a bypass port connected downstream of the air compressor. The fuel supply system can also include a fuel injector attached to the compressed air supply port or the bypass port, and a valve connected between the air compressor and the air cooler. The valve is designed to either block the flow of intake air to the air cooler, causing the intake air to flow to the bypass port, or to allow the intake air to flow to the air cooler.

[0007] In another aspect, a fuel supply system may include an internal combustion engine, an air compressor designed to compress the air received by the engine, an air cooler to reduce the temperature of the compressed air, and a compressed air bypass port connected downstream of the air compressor. The fuel supply system may also include a fuel injector attached to the compressed air supply port or the compressed air bypass port, a bypass valve with a bypass position designed to cause at least some of the compressed air to bypass the air cooler, and an electronic control module designed to generate a command to cause the bypass valve to enter the bypass position.

[0008] In another aspect, a fuel supply method for supplying an internal combustion engine with fuel can include compressing air with an air compressor, injecting fuel into the compressed air at a point upstream of an intake plenum to form a fuel-air mixture, wherein the intake plenum is part of an intake manifold with a plurality of channels extending from the intake plenum towards the internal combustion engine, and causing at least a portion of the compressed air to bypass an air cooler. The method can also include supplying the air-fuel mixture to the internal combustion engine and burning the air-fuel mixture within the internal combustion engine. Brief description of the drawings Fig. Figure 1 is a schematic view of an intake and combustion system according to aspects of the disclosure. Fig. Figure 2 is a block diagram showing an electronic control module for the intake and combustion system of Fig. 1 represents. Fig. Figure 3 is a flowchart illustrating an exemplary fuel supply procedure related to the intake and combustion system of Fig. 1 is useful. Detailed description

[0009] Both the preceding general description and the following detailed description are merely exemplary and explanatory and do not limit the features as claimed. As used herein, the terms "comprises," "comprising," "having," "incorporating," or other variations thereof are intended to cover a non-exclusive inclusion, such that a method or apparatus comprising a list of elements may include not only those elements but also other elements not expressly listed or inherent to such method or apparatus. In this disclosure, relative terms such as "approximately," "essentially," "generally," or "about" are used to indicate a possible deviation of ±10% of the stated value or feature.As used herein, “intake air” is defined as including both air free of fuel and air containing at least some fuel, regardless of whether that fuel is in liquid form, in vaporized form or as a mixture of liquid droplets and vaporized fuel, unless it is expressly stated that the air contains no fuel.

[0010] Fig. Figure 1 illustrates an exemplary intake and combustion system 12 according to aspects of the invention. The intake and combustion system 12 can be part of a watercraft, a machine, a vehicle, or a power generation system and may include an internal combustion engine 14 and an air and fuel supply system 16. The air and fuel supply system 16 may be connected to the engine 14 and enable the compression of the intake air, the introduction of fuel into the compressed air, and the supply of the compressed air and fuel to the engine 14, at least during some operating conditions of the engine 14.

[0011] The intake and combustion system 12 can include one or more electronically controlled components, such as a flow control valve 30, one or more feedback devices, and one or more electronic control devices. Feedback devices of the intake and combustion system 12 can include a sensor system 70, which contains sensors designed to generate signals that enable control of the flow control valve 30. An electronic control module (ECM) 80 of the system 12 can monitor the states of the system 12 via the sensor system 70. The ECM 80 can be programmed to generate commands that enable the desired operation of the electronically controlled components, such as the valve 30, based on the feedback signals received from the sensor system 70. The ECM 80 can be a control module for controlling multiple functions of the system 12 and the engine 14, as shown in Fig. 1 shown. Alternatively, the ECM 80 can also be an electronic control module or electronic control unit designed to control aspects of the air and fuel supply system 16 and, in particular, the flow control valve 30.

[0012] The engine 14 can include a plurality of cylinders 42 in which fuel injected by the fuel injector 26 can be burned. In addition to an injector located upstream of an intake manifold and / or near the outlet of an air compressor, such as the fuel injector 26, the engine 14 can include one or more direct fuel injectors 44 designed to inject a second fuel, such as diesel fuel, directly into the respective cylinders 42 of the engine 14. The second fuel can be useful for generating a flame that ignites the fuel injected by the fuel injector 26.However, in at least some configurations, a spark-generating device may be present to initiate the combustion of fuel within cylinder 42, thereby enabling the engine 14 to operate entirely on an alternative fuel injected by the fuel injector 26. While the internal combustion engine 14 is in . Fig. While engine 1 is illustrated as a 16-cylinder engine with two cylinder banks, engine 14 can of course also have more or fewer cylinders (42) and one cylinder bank.

[0013] Suitable fuels for injector 26 can include fuels stored in liquid form, such as an alcohol. Examples of alternative fuels include methanol, ethanol, butanol, propanol, and / or other alcohols, including mixtures thereof, ammonia, or dimethyl ether. An alcoholic liquid fuel can contain at least approximately 50% alcohol by volume, such as a fuel containing approximately 85% methanol by volume or approximately 85% ethanol by volume. Engine 14 can also be designed to operate entirely on fuel injected by one or more direct fuel injectors 44. Thus, depending on the operating conditions, engine 14 can operate entirely on an alternative fuel, such as methanol, on a mixture of the alternative fuel and a second fuel (e.g., diesel fuel), or entirely on the second fuel.

[0014] The air and fuel supply system 16 can include a number of passages for supplying air to the engine 14, including an air inlet 20, an air compressor 22 of a turbocharger, and a compressed air passage 24 downstream of an outlet of the compressor 22. The air and fuel supply system 16 can also include a compressed air cooler 34 (also referred to as an "aftercooler") connected to an air cooler outlet 38, a bypass passage 32 for compressed air and, optionally, fuel to bypass the air cooler 34, and an intake manifold 50 with an intake plenum 36 and a plurality of channels 40. The air and fuel supply system 16 can also include components for supplying the engine 14 with fuel (e.g., fuel stored as a liquid), as described below. The air inlet 20 can include one or more passages, air filters, etc.The system includes components designed to draw in ambient air from outside the system 12. The compressor 22, connected downstream of the air inlet 20, can be a radial compressor connected via a shaft to a turbine 52 to compress air for combustion in the engine 14. An outlet of the compressor 22 can be connected to the compressed air passage 24. While the compressor 22 can be driven by the exhaust gas flow through the turbine 52, it can also be driven mechanically or electrically if required.

[0015] The air and fuel supply system 16 can include a forked intake air path downstream of the compressor 22, extending, for example, from the compressed air passage 24. In the Fig. In the configuration shown in Figure 1, a relatively short first path can extend from the compressor outlet 22, this first path including the compressed air passage 24, the flow control valve 30, the air cooler 34, and the air cooler outlet 38. A second path, which may be longer than the first path, can also extend from the compressor outlet 22. This second path can include at least a section of the compressed air passage 24 and the bypass passage 32. As shown in Figure 1, the first path includes the compressed air passage 24, the flow control valve 30, the air cooler 34, and the air cooler outlet 38. Fig. As shown in Figure 1, the bypass passage 32 can extend from the compressed air passage 24, forming a connection with it. In a first configuration, the flow control valve 30 can be included as part of both the first and second paths. However, the valve 30 can also be located at an alternative position 31. A valve at an alternative position 31 can cause an intake air flow to bypass the bypass passage 32 when it is in a closed or partially closed position, in which the valve 30 prevents at least some of the intake air from flowing through a section of the first path.

[0016] The intake plenum 36 can be connected to both the bypass passage 32 and the air cooler outlet 38. The intake plenum 36 can be part of an intake manifold 50, which also includes a plurality of channels 40, each connected to the cylinders 42 of the internal combustion engine 14. Each channel 40 of the intake manifold 50 can connect a corresponding engine cylinder 42 of the internal combustion engine 14 to the intake plenum 36 to supply air and fuel to that cylinder 42. If required, the intake manifold 50, and in particular the intake plenum 36, can be free of a fuel injector, since the fuel injected by indirect injection is supplied via the fuel injector 26 or an injector at location 28, as described below.

[0017] An exhaust manifold 46 downstream of the cylinders 42 can be designed to receive exhaust gases generated during the combustion of air and fuel. These exhaust gases can be directed through an outlet 48 to the turbine 52 of the turbocharger, which consists of a compressor 22 and a turbine 52. The turbine 52 can be driven by exhaust gases leaving the system 12 via an exhaust outlet 54. If required, the exhaust outlet 54 can include one or more aftertreatment devices, such as a catalytic converter or a particulate filter, to reduce the emission of undesirable components, such as NOx or soot, which can be generated during partial or complete operation of the engine 14 with diesel fuel.

[0018] As already mentioned, the air and fuel supply system 16 can include one or more fuel injectors 26. The injectors 26 can be located upstream of the intake manifold 50 and, in particular, connected upstream of the intake plenum 36 of the intake manifold 50. Fuel injectors 26 can be designed to inject fuel stored in one or more liquid fuel storage devices into a channel that carries compressed air to the engine 14. In the Fig. In the exemplary configuration shown in Figure 1, the fuel injectors 26 are attached at an alternative location 28 on the compressed air passage 24 and / or on the bypass passage 32.

[0019] The flow control valve 30 can be designed to control an airflow, and in some configurations also to control an air-fuel mixture supplied to the air cooler 34. The flow control valve 30 can be located upstream of the air cooler 34 and, in particular, connected between the air cooler 34 and the compressor 22. In at least some embodiments, the flow control valve 30 is a three-way valve, as shown in Fig. Figure 1 shows the flow control valve 30. It can include a first inlet downstream of the compressor 22, a first outlet connected to the air cooler 34, and a second outlet connected to the bypass passage 32, such that an intake airflow (air or air-fuel mixture) flowing through the first outlet does not enter the bypass passage 32, and an intake airflow flowing through the second outlet bypasses the air cooler 34. In some configurations, the flow control valve 30 can have a first position in which the entire flow is directed through the valve 30 to the air cooler 34, and a second position in which the entire flow is directed through the valve 30 to the bypass passage 32.The flow control valve 30 can be a proportional valve comprising a plurality of third positions in which at least a portion of the flow passes through the valve 30 to the air cooler 34 and at least a portion of the flow passes through the valve 30 to the bypass passage 32. If the flow control valve 30 is a proportional valve, the flow allowed to the air cooler 34 can be determined by the electronic control module 80 in comparison to the flow allowed to the bypass passage 32, as described below. The ECM 80 can also be configured to control the valve 30 in configurations in which the valve 30 is not a proportional valve.

[0020] In at least some configurations, the flow control valve 30 can be located in the compressed air passage 24 at a point downstream of the connection between the compressed air passage 24 and the bypass passage 32. For example, the flow control valve 30 can be located at point 31, which is in Fig. 1 is represented by a dashed outline. Location 31 can be situated downstream of a connection between the compressed air passage 24 and the bypass passage 32. In this configuration, a bypass valve at location 31 can be a throttle valve, a solenoid valve, or another suitable type of valve designed to regulate flow from the compressor 22 to the air cooler 34.

[0021] In some aspects, the flow control valve 30 at location 31 can be a proportional two-way valve, including a fully open position in which complete flow from the compressed air passage 24 to the air cooler 34 is permitted, a fully closed position in which no flow to the air cooler 34 is permitted, and a variety of intermediate positions in which the flow from the compressed air passage 24 to the air cooler 34 is regulated such that at least part of the flow from the compressed air passage 24 is diverted to the bypass passage 32. Similar to the three-way proportional valve described above, the desired position (e.g., a desired partially open position) can be determined using ECM 80.In some configurations, when at least a portion of the intake air is supplied to the bypass passage 32, the ECM 80 can control one or more heaters (not shown) along the bypass passage 32 to generate heat to warm the fuel contained in this air, thus enabling the vaporization of that fuel. If heaters are present along the passage 32, they may be electrically driven. If required, a heat exchanger using jacket water or engine oil can be positioned near the passage 32 to provide wall temperatures between approximately 90°C and 95°C in one or more sections of the passage 32.

[0022] Regardless of whether the flow control valve 30 is a three-way or a two-way valve, the valve 30 can be electronically controlled. In particular, the flow control valve 30 can be controlled by an electronic control module 80 based on one or more signals generated by the sensor system 70. The position of the flow control valve 30 can allow the vaporization of the liquid fuel injected by the fuel injector 26.In some configurations, for example, the arrangement of the valve 30 between a fuel source such as the fuel injector 26 and the air cooler 34 can enable the valve 30 to cause at least part of the fuel injected by the fuel injector 26 to bypass the air cooler 34 and take a longer path and thus a greater distance to the engine 14, thereby increasing the residence time of the injected fuel at elevated temperature before the fuel reaches the engine 14.

[0023] In some aspects, the arrangement of a liquid fuel injector (e.g., fuel supplied to a fuel injector in liquid form), such as methanol, can be adjusted to increase the residence time of the injected fuel before reaching the engine 14. For example, the fuel injector 26 can be located upstream of the air cooler 34, as shown in Fig. 1 shown, and in particular arranged between the flow control valve 30 (or a valve at position 31) and the air inlet 20. If the fuel injector 26 is, as in Fig. As shown in Figure 1, attached to the compressed air passage 24, the fuel injector 26 enables the flow control valve 30 to regulate the proportion of fuel that bypasses the air cooler 34. An alternative fuel injector location 28, which is in Fig. The bypass port 32, shown as a dashed line, can be used to allow the entire quantity of injected fuel to bypass the air cooler 34. Alternative location 28, or other alternative locations, can mount a fuel injector upstream of the fuel distributor 50 and downstream of the compressor 22. In particular, a fuel injector at location 28 can be mounted directly on the bypass port 32, so that all the injected fuel bypasses the air cooler 34, regardless of the position of the flow control valve 30 (or a flow control valve at location 31). In some aspects, the presence of a fuel injector at location 28 can allow all of the injected fuel to bypass the cooler 34, while some of the air can still flow through the cooler 34. If necessary, the injectors at both locations can be connected. Fig. 1 specified locations or at one or more other locations.

[0024] The sensor system 70 can include sensors for monitoring aspects of the air and fuel supply system 16 and / or the engine 14. In the Fig. In the exemplary configuration illustrated in Figure 1, the sensor system 70 includes an intake manifold sensor 72, an engine sensor 74, an intake air sensor 76, and a turbocharger sensor 78. The intake manifold sensor 72 may include a temperature sensor designed to generate a signal indicating the temperature of the intake air supplied to or contained within the intake manifold 50, a pressure sensor designed to generate a signal indicating the pressure of the intake air supplied to or contained within the intake manifold 50, or both. It is understood that the signal generated by the intake manifold sensor 72 may correspond to an air-fuel mixture. The engine sensor 74 may be designed to monitor one or more engine states 14 that are useful for calculating the fuel quantity or engine load, such as engine speed. If necessary, the engine sensor 74 may measure the engine temperature (e.g.,The intake air sensor 76 can monitor the engine oil temperature or other engine conditions (by measuring the engine oil temperature). The intake air sensor 76 can detect air conditions before the air enters the compressor 22, such as airflow velocity. The intake air sensor 76 can also include temperature and / or pressure sensors. The turbocharger sensor 78 can monitor the speed of a turbocharger and output a signal indicating the speed of the compressor 22.

[0025] The ECM 80 can be programmed to receive signals from sensors of the system 70 and generate commands for the control valve 30. In particular, the ECM 80 can be configured to control the position of the flow control valve 30 based on one or more signals received from the sensor system 70 to enable complete vaporization of the fuel injected upstream of the intake manifold 50. The ECM 80 can also generate commands that control injections performed by the fuel injector 26 and the direct fuel injectors 44.

[0026] ECM 80 can embody a single microprocessor or multiple microprocessors that receive inputs and produce outputs. ECM 80 can include a memory, a secondary storage device, a processor such as a central processing unit, or any other means for performing a task as defined in this disclosure. The memory or secondary storage device associated with ECM 80 can store data and software that enables ECM 80 to perform its functions, including the functions described in relation to Method 300 below. Numerous commercially available microprocessors can be configured to perform the functions of ECM 80. Various other known circuits, including signal conditioning circuits, communication circuits, and other suitable circuits, can be associated with ECM 80.

[0027] Fig. Figure 2 is a block diagram illustrating an example configuration of the ECM 80. As shown in Fig. As shown in Figure 2, the ECM 80 can receive inputs 210, including inputs generated by the sensor system 70, as previously described. The ECM 80 can include one or more modules (e.g., programming) that enable the ECM 80 to generate outputs 250 based at least partially on one or more inputs 210. The ECM 80 can include a fuel mode module 230 that enables the ECM 80 to determine whether fuel should be injected by the fuel injector 26, by one or more direct fuel injectors 44, or by both. A bypass mode module 240 can receive fuel mode information (e.g., injector commands 252) from the fuel mode module 230 and can generate a bypass command 254 to control the flow control valve 30 based on one or more inputs 210 and the received fuel mode information.

[0028] The inputs 210 can contain signals generated by one or more sensors of the sensor system 70. For example, an intake pressure signal 212 can be generated by the intake manifold sensor 72 to indicate the pressure of the air drawn in by the intake manifold 50. An intake temperature signal 214 can be generated by the intake manifold sensor 72 or an additional intake manifold sensor. The engine speed signal 216 can be generated by the engine sensor 74. An intake air flow signal 218 can indicate the amount of air drawn in by the compressor 22, as measured by the intake air sensor 76. The compressor speed signal 220 can correspond to the speed of the compressor 22 detected by the turbocharger sensor 78.

[0029] The fuel mode module 230 can enable the ECM 80 to determine whether the engine 14 is operating on fuel from fuel injector 26. For example, the fuel mode module 230 can determine that the engine 14 is operating exclusively on fuel from fuel injector 26. This can be done in response to a manual request from an engine 14 operator when reduced emissions from the engine 14 are desired. In a specific example, an engine 14 operator might request low-emission operation of the engine 14 if the engine 14 is a marine engine currently located in a location where low emissions are desired or required (e.g., in a port). The fuel mode module 230 can also be configured to operate the engine 14 on fuel from fuel injector 26 when the engine 14 is idling, operating at low load, or at medium load.When engine 14 is operating under high load, the fuel mode module 230 can direct engine 14 to operate on fuel from both fuel injector 26 and direct fuel injectors 44, or exclusively on fuel from direct fuel injectors 44. In some respects, the injector commands 252 generated by the fuel mode module 230 can be adjusted according to fuel availability. For example, if diesel fuel is scarce, the module 230 can issue commands that tend to inject a larger quantity of fuel through fuel injector 26. Accordingly, the injector command 252 generated by the fuel mode module 230 can include commands issued to fuel injector 26 and / or one or more direct fuel injectors 44 to inject fuel in a desired manner.

[0030] The bypass mode module 240 can receive a desired fuel mode from the fuel mode module 230. As described above, this desired fuel mode can involve fuel injection exclusively by the fuel injector 26 (a first mode), exclusively by one or more direct fuel injectors 44 (a second mode), or dual fuel injection (a third mode) involving both the fuel injector 26 and one or more direct fuel injectors 44. In some aspects, the bypass mode module 240 can generate a bypass command for the flow control valve 30 based on this desired fuel mode and based on inputs 210, which include factors that affect the ability of the fuel injected by the fuel injector 26 to evaporate during the first and third modes.

[0031] In some aspects, the bypass mode module 240 can generate a bypass command 254 to instruct the flow control valve 30 in a manner that ensures the vaporization of the fuel injected by the fuel injector 26. In some aspects, the bypass mode module 240 can include mathematical relationships and / or a model that calculates a position of the valve 30 that allows the vaporization of fuel droplets injected by the fuel injector 26 or a fuel injector at location 28. For example, the bypass mode module 240 can be designed to determine whether the current engine conditions represented by the inputs 210 would not result in sufficient vaporization of the fuel injected by the fuel injector 26.Under these conditions, the bypass mode module 240 can therefore generate a bypass command 254, which increases the amount of intake air bypassing the air cooler 34, thereby transferring more energy from the air to the fuel for evaporation and extending the residence time of this fuel before entering the engine 14. Commercial applicability

[0032] The disclosed aspects of the intake and combustion system 12 can be used in a variety of internal combustion engines designed to burn fuels, including internal combustion engines for burning a fuel with low greenhouse gas emissions, such as methanol. The system 12 can be incorporated as a propulsion or power generation system useful for operating a watercraft, machine (e.g., bulldozer, excavator, loader, pipe-laying machine, grader, etc.), vehicle, or other device that uses an internal combustion engine. During operation of the system 12, the cylinders 42 of the engine 14 can burn fuel, including fuel injected by one or more indirect injectors located upstream of an intake manifold.System 12 can include one or more valves, such as the flow control valve 30, which allows the vaporization of fuels other than diesel fuel, such as methanol. For example, system 12 can generate signals to actuate valve 30 in a way that increases the air temperature supplied to engine 14 by causing this air to bypass a cooler. Additionally, system 12 can allow for a longer residence time of the injected fuel, causing it to bypass a cooler before being drawn into an intake manifold and directed to an engine cylinder 42.

[0033] Fig. Figure 3 is a flowchart illustrating an exemplary fuel supply and combustion process 300 for the operation of system 12. During the operation of system 12 according to process 300, compressed air can be supplied to an air and fuel supply system 16 in step 302. The supply of compressed air can include compressing the air with the compressor 22 and directing the air through the compressed air passage 24. The air supplied in step 302 can initially be free of fuel.

[0034] Step 304 may involve injecting fuel into the compressed air supplied in step 302. In a particular example, methanol may be injected through the fuel injector 26, which may be attached to the compressed air passage 24 or to location 28. The fuel injected in step 304 may be stored in liquid form. This fuel may be injected as a multitude of droplets that enter an air stream compressed by the compressor 22.

[0035] Step 306 may involve bypassing at least some of the air compressed in step 302 and the fuel injected in step 304 by a cooler, such as the air cooler 34. This may cause the temperature of the fuel supplied to the engine 14 to increase. In some aspects, step 306 may involve generating a bypass command 254 based on one or more signals generated by the sensor system 70 (e.g., signals 212, 214, 216, 218, 220). In particular, the bypass command 254 may be generated by the ECM 80 based on signals useful for estimating whether fuel from the injector 26 will evaporate before reaching an engine cylinder 42 or the intake manifold 50.In particular, signals indicating the conditions within the intake manifold 50, such as the intake pressure signal 212 and / or the intake temperature signal 214, can be used to determine whether the liquid fuel droplets will completely evaporate before reaching the cylinder 42.

[0036] In addition to signals 212 and 214, signals 216, 218, 220, and / or the fuel mode information determined by the fuel mode module 230 (e.g., the first or third mode described above) can enable the ECM 80 to determine whether the fuel will completely vaporize. As described above, the ECM 80 can, for example, use mathematical relationships and / or a model-based approach to determine whether fuel is likely to vaporize based on signals 212, 214, 216, 218, and / or 220. A model-based approach may include a model for the vaporization of the injected fuel based on the temperature and pressure of the intake air within the intake plenum 36. Other data useful for vaporization modeling may include the engine load, the amount of fuel, and other conditions of the system 12.

[0037] If the ECM 80 determines in step 306 that complete vaporization of the fuel is unlikely, the ECM 80 can generate the bypass command 254 to block or reduce the flow to the cooler 34 in response to the determination that, in the absence of a bypass command, some of the fuel could reach the engine 14 in a liquid state. The bypass command 254 generated during step 306 can cause at least some of the air from the compressor 22 to bypass the air cooler 34 and enter the intake manifold 50 via the bypass passage 32. In embodiments where the fuel injector 26 is attached to the compressed air passage 24, the bypass command 254 can also cause at least some of the fuel injected by the fuel injector 26 to bypass the air cooler 34.In embodiments where the fuel is injected by an injector at location 28, however, all of this fuel can bypass the cooler 34, while part of the air bypasses the air cooler 34.

[0038] Step 308 can involve the combustion of the air supplied in step 302, the fuel injected in step 304, and the portion of air and fuel bypassing the air cooler 34 in step 306. For example, methanol fuel, at least a portion of which is bypassed by the air cooler 34 with some compressed air, can be burned within the cylinders 42 of the engine 14. This combustion can be initiated by using a second fuel, such as diesel fuel, to create a pilot flame (e.g., by compression ignition of diesel fuel). In alternative embodiments or at other times, this combustion can be initiated by spark plugs of the engine 14. Therefore, step 308 can involve the combustion of only the fuel bypassed by the cooler 34 or only the fuel injected by indirect injection. This fuel can be methanol.At other times and / or in other embodiments, step 308 may involve the combustion of fuel, part of which bypasses the cooler 34 and another part of which flows through the cooler 34.

[0039] Although steps 302, 304, 306 and 308 of procedure 300 were described in an exemplary order and in Fig.Although the steps in Figure 3 are shown in an exemplary sequence, one or more of them can, of course, be performed in a different order, over partially or fully overlapping time periods, etc. Additionally, one or more of steps 302, 304, 306, 308, and other aspects of Procedure 300 can be performed intermittently during the operation of the engine 14, while one or more other steps or aspects of Procedure 300 can be performed continuously during the operation of the engine 14. For example, the compressed air can be supplied at regular or continuous intervals during the operation of the engine 14, while the period during which the air passes over the cooler 34 can be intermittent or periodic, based on the investigations carried out by the EMC 80 described above and the current operating conditions of the system 12.Thus, as part of the procedure 300, the system 12 and the ECM 80 can assess when it is desirable to cause air, fuel or both to be routed past the air cooler 34 to allow the complete vaporization of the fuel stored in liquid form, such as methanol.

[0040] The disclosed system and method can enable the use of one or more low-greenhouse-gas fuels, fuels from renewable sources, low-soot fuels, and others that can be stored in liquid form and / or fed in liquid form to an injector located upstream of the intake manifold. In one particular example, the disclosed system and method can be useful for methanol fuel injected into a path that allows the fuel to bypass a cooler, at least under certain operating conditions. Furthermore, under certain operating conditions, the disclosed system and method can allow at least a portion of the air to bypass an air cooler. These features can enable the complete vaporization of this fuel. In some aspects, the disclosed system and method can enable the injection of methanol, which has a relatively high latent heat of vaporization.In particular, bypassing part of the air or air-fuel mixture in at least some embodiments can enable the injection of larger quantities of methanol and provide additional residence time and / or higher temperatures to allow the complete vaporization of this methanol or other fuel.

[0041] It is obvious to those skilled in the field that various modifications and variations can be made to the disclosed system and method without deviating from the scope of protection of the disclosure. Other embodiments of the system and method will be obvious to those skilled in the field, taking into account the specification and the method and system disclosed herein. The description and examples are intended to be considered merely exemplary, with the actual scope of the disclosure being specified by the following claims and their equivalents. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 214366438 U

[0004]

Claims

[1] Fuel supply system (16) for an internal combustion engine (14), the fuel supply system (16) comprising: an air compressor (22); a compressed air supply passage (24) which is connected downstream of the air compressor (22); an air cooler (34) which is connected downstream of the air compressor (22) and the compressed air supply passage (24); a bypass passage (32) which is connected downstream of the air compressor (22); a fuel injector (26) attached to the compressed air supply passage (24) or the bypass passage (32); and a valve (30) connected between the air compressor (22) and the air cooler (34), wherein the valve (30) is designed to block an intake air flow to the air cooler (34), causing the intake air to flow to the bypass passage (32), or to allow the intake air to flow to the air cooler (34). [2] Fuel supply system (16) according to claim 1, wherein the valve (30) includes an inlet opening connected between the air compressor (22) and the air cooler (34) and an outlet connected between the inlet and the air cooler (34). [3] Fuel supply system (16) according to claim 2, wherein the valve (30) further includes an additional outlet connected between the inlet and the bypass passage (32). [4] Fuel supply system (16) according to one of the preceding claims, wherein the fuel injector (26) is connected upstream of the air cooler (34). [5] Fuel supply system (16) according to claim 1, wherein the fuel injector (26, 28) is attached to the bypass passage (32). [6] Fuel supply system (16) according to one of the preceding claims, further comprising an additional fuel injector (44) designed for direct injection of fuel into a cylinder (42) of the internal combustion engine (14). [7] Fuel supply system (16) according to claim 6, wherein the fuel injector (26) attached to the compressed air supply passage (24) is designed to inject a liquid fuel which is different from a fuel injected by the additional fuel injector (44). [8] Fuel supply method (300) for supplying fuel to an internal combustion engine, the method comprising: Compressing air with an air compressor (22); Injection of fuel into the compressed air at a location upstream of the intake plenum (36) to form a fuel-air mixture, wherein the intake plenum (36) is part of an intake manifold (50) having a plurality of channels (40) extending from the intake plenum (36) to the internal combustion engine (14); Causing at least some of the compressed air to be directed past an air cooler (34); Supplying the air and fuel mixture to the internal combustion engine (14); and Combustion of the air and fuel mixture within the internal combustion engine (14). [9] Fuel supply method (300) according to claim 8, wherein the fuel is injected upstream of the air cooler (34). [10] Fuel supply method (300) according to claim 8 or claim 9, further comprising controlling a bypass valve (30) to cause at least a part of the air-fuel mixture to bypass the air cooler (34).

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