Patent ID: 12215640

DETAILED DESCRIPTION

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.FIG.1illustrates an internal combustion engine system100, in accordance with various examples of the presently disclosed subject matter. The internal combustion engine system100includes an internal combustion engine102with a plurality of combustion cylinders (not shown), with illustrative combustion cylinder104identified inFIG.1. However, it should be noted that the internal combustion engine102may have any number of combustion cylinders. The combustion cylinder104is associated with a piston (not shown) movable between a top dead center position and a bottom dead center position in a generally conventional manner, typically in a four-stroke engine cycle, though other combustions cycles may be used and are considered to be within the scope of the presently disclosed subject matter. The pistons will be coupled with a crankshaft (not shown) rotatable to provide torque for purposes of vehicle propulsion, operating a generator for production of electrical energy, or in still other applications such as operating a compressor, a pump, or various other types of equipment.

Air106for combustion is provided through air intake108into a turbocharger110. The turbocharger110includes a compressor112, a shaft114, and a turbine116. The compressor112includes a series of fans or blades (not shown) internal to the compressor112that compress the air106into compressed intake air118from air106pressure to a higher pressure for combustion by the internal combustion engine102. The fans of the compressor112are rotatably attached to the shaft114, so that when the shaft114rotates, the fans of the compressor112rotate. The shaft114is rotated by internal fans of the turbine116. The turbine116receives combustion exhaust120from the internal combustion engine102. The combustion exhaust120is at a first pressure that, when received into the turbine116, causes the fans of the turbine116to rotate, rotating the shaft114, and thus, rotating the fans of the compressor112. The turbine116reduces the pressure of the combustion exhaust120from the first pressure to the second pressure, leaving the turbine116as engine exhaust122. Intercoolers and other heat exchange mechanisms (not shown) may be used to cool various fluids moving the internal combustion engine system100, such as, but not limited to, the compressed intake air118. Further, compressed air may be provided using technologies other than the compressor112of the turbocharger110. For example, but not by way of limitation, a supercharger, compressor pump, or battery-operated compressor may be used and are considered to be within the scope of the presently disclosed subject matter.

The compressed intake air118is received into the cylinder104of the internal combustion engine102through intake valve124. When open, the compressed intake air118enters the cylinder104, and when closed, the compressed intake air118is prevented from entering the cylinder104. In an exemplary four stroke engine cycle, the intake valve124will be open during the “air intake” cycle, and will be closed during the combustion, power, and exhaust cycles. During the exhaust cycle, the combustion exhaust120exits the cylinder104through exhaust valve126. In an exemplary four stroke engine cycle, the exhaust valve126will be open during the “exhaust” cycle, and will be closed during the air intake, combustion, and power cycles.

The internal combustion engine102is fueled by a first fuel128stored in a first fuel tank130and a second fuel132stored in a second fuel tank134. The first fuel128may include a higher cetane/lower octane liquid fuel, and the second fuel132may include a lower cetane/higher octane liquid fuel. The terms “higher” and “lower” in this context may be understood as relative terms in relation to one another. Thus, the first fuel128may have a higher cetane number and a lower octane number than a cetane number and an octane number of the second fuel132. The first fuel128might include a diesel distillate fuel, dimethyl ether, biodiesel, Hydrotreated Vegetable Oil (HVO), Gas to Liquid (GTL) renewable diesel, any of a variety of liquid fuels with a cetane enhancer, or still another fuel type. The second fuel132may include an alcohol fuel such as methanol or ethanol, Naptha, for example, or still other fuel types such as isopropyl alcohol, n-propyl alcohol, and t-butyl alcohol. For the purposes ofFIG.1, the first fuel128is described as diesel fuel and the second fuel132is described as methanol, though as noted above, the presently disclosed subject matter may be used with other fuel types.

In various examples, the first fuel128is pumped into a first fuel injector136using first fuel pump138. The first fuel pump138is in fluidic communication with the first fuel tank130and pumps the first fuel128to the first fuel injector136. The first fuel injector136is a valve that, when opened, allows the first fuel128to enter the cylinder104for combustion. It should be noted, however, that the first fuel128may be provided to the cylinder104for combustion using other injection technologies. The presently disclosed subject matter is not limited to any particular method of injecting the first fuel128into the cylinder104. The second fuel132is supplied to the internal combustion engine102through second fuel injector140, which injects the second fuel132into the compressed intake air118, illustrated in more detail inFIG.2, below.

FIG.2is an illustration of the first fuel injector136, the second fuel injector140, the intake valve124, the cylinder104, and the exhaust valve126of the internal combustion engine102, in accordance with various examples of the presently disclosed subject matter. The compressed intake air118enters the internal combustion engine102through an intake manifold202. When open, the compressed intake air118enters the cylinder104through the intake valve124. The combustion exhaust120exits the cylinder104through an exhaust manifold204. The first fuel128enters the cylinder104through the first fuel injector136. The second fuel132is injected into the intake manifold202for delivery into the cylinder104when the intake valve124is open. The second fuel132is received into the second fuel injector140through injector inlet206. A fuel valve208moves in a direction along axis AB to permit or abate the flow of the second fuel132through port inlet210by blocking or closing the port inlet210.

The position of the fuel valve208is controlled by windings212. The fuel valve208is configured to be sensitive to magnetic fields so that when energized, the windings212create an electromagnetic field that moves the fuel valve208from position A to position B along the AB axis, thus opening the fuel valve208to allow the second fuel132to move through the port inlet210. The windings are energized by the injector signal168. To stop the flow of the second fuel132through the port inlet210, the controller148removes the injector signal168, thus deenergizing the windings212, allowing the fuel valve208to move from position B to position A along the AB axis. A spring214provides a biasing force to assist the movement of the fuel valve208from position B to position A along the AB axis.

Returning toFIG.1, a second fuel pump142is in fluidic communication with the second fuel132stored in the second fuel tank134, increases the pressure of the second fuel132at or above the pressure of the compressed intake air118so that the second fuel132flow moves from the second fuel pump142, when operating, into the compressed intake air through the second fuel injector140. Flow of the second fuel132into the second fuel injector140is abated using a second fuel cutoff valve144. Similarly, the flow of the first fuel128into the first fuel injector136is abated using first fuel cutoff valve146.

To control the flow of the first fuel128and the second fuel132into the internal combustion engine102, a controller148is provided. The controller148can be an engine control unit (ECU) or engine control module (ECM), or a module of the ECU or ECM, of the internal combustion engine102. The controller148controls the amount and timing of the first fuel128and the second fuel132entering the internal combustion engine102. The controller148includes one or more processors and memory storing therein instructions that, when executed by the processor of the controller148, cause the controller148to control the amount and timing of the first fuel128and the second fuel132entering the internal combustion engine102, explained in more detail inFIG.5, below.

Returning toFIG.1, during operation, the controller148opens and closes the second fuel cutoff valve144and the first fuel cutoff valve146using cutoff signals150and152, respectively. The cutoff signal150is used to control a second fuel actuator154. The second fuel actuator154opens and closes the second fuel cutoff valve144. Similarly, the cutoff signal152is used to control a first fuel actuator156. The first fuel actuator156opens and closes the first fuel cutoff valve146. When closed, the first fuel cutoff valve146and the second fuel cutoff valve144prevent the flow of their respective fuels. The first fuel cutoff valve146and the second fuel cutoff valve144may be various types of valves, such as a gate valve that either permits or abates the flow of fluid or a throttle valve that, depending on the position of the throttle valve, adjusts the flow rate of the fluid. The presently disclosed subject matter is not limited to any particular type of valve for the first fuel cutoff valve146and the second fuel cutoff valve144. The controller148further turns on and turns off (i.e., energizes and deenergizes) the second fuel pump142using second pump control signal162and the first fuel pump138using first pump control signal164.

The controller148opens and closes the first fuel injector136using injector signal166. The injector signal166, when active, causes the first fuel injector136to open to allow the first fuel128to enter the cylinder104. The injector signal166, when deactivated, causes the first fuel injector136to close, preventing the first fuel128from entering the cylinder104. The controller148further opens and closes the second fuel injector140using injector signal168. The injector signal168, when active, causes the second fuel injector140to open, allowing the second fuel132to enter the compressed intake air118. In some examples, the second fuel injector140is opened proximate to or substantially at the same time the intake valve124is open. When the intake valve is open, the compressed intake air118will be flowing into the cylinder104, providing a flow of moving fluid that increases a mixing of the second fuel132into the compressed intake air118. The injector signal168, when deactivated, causes the second fuel injector140to close, preventing the second fuel132from entering the compressed intake air118. In some examples, the second fuel injector140is closed proximate to or substantially during the time the intake valve124is closed.

As noted above, in some examples, it may be preferable or required to purge at least a portion of the second fuel132from one or more components of the internal combustion engine102. To purge at least a portion of the second fuel132from one or more components of the internal combustion engine102, the internal combustion engine system100uses the compressed intake air118. As discussed above, during the air intake cycle of the internal combustion engine, the second fuel injector140and the intake air118are open, allowing the second fuel132to move into the compressed intake air118for delivery to the cylinder104of the internal combustion engine102. When the intake air118is closed, the second fuel injector140is normally closed. However, during a purge cycle, the controller148issues the injector signal168to open the second fuel injector140to allow the compressed intake air118to move into the second fuel injector140and towards the second fuel cutoff valve144, and ultimately into the second fuel tank134. However, during the operation of the internal combustion engine102, the second fuel pump142provides enough outlet pressure that the pressure of the second fuel132moving into the compressed intake air118is greater than the pressure of the compressed intake air118. If the second fuel injector140is opened by the controller148during a purge operation when the pressure of the second fuel132is greater than the pressure of the compressed intake air118, the compressed intake air118could not flow into the second fuel injector140to purge.

Therefore, to reduce the pressure of the second fuel132to allow the compressed intake air118to enter the second fuel injector140to purge, the controller148issues the second pump control signal162to deenergize the second fuel pump142. With the second fuel pump142deenergized, which pressurized the second fuel132, the pressure of the second fuel132is reduced to a level below the compressed intake air118. Having the second fuel132at a pressure less than the compressed intake air118allows the compressed intake air118, when the second fuel injector140is open, to push portions of the remaining second fuel132back through the second fuel injector140, through the second fuel cutoff valve144, the second fuel pump142and into the second fuel tank134.

Because the differential pressure between the second fuel132and the compressed intake air118provides for the flow of the compressed intake air118into the second fuel injector140to purge the second fuel, the internal combustion engine system100also includes and intake air sensor, an intake pressure sensor170, and second fuel pressure sensor172. The intake pressure sensor170and second fuel pressure sensor172are in communication with the controller148. The intake pressure sensor170provides a communication to the controller148indicating the pressure of the compressed intake air118. The second fuel pressure sensor172provides a communication to the controller148indicating the pressure of the second fuel132prior to the second fuel injector140. A used herein, “prior” is the pressure of the second fuel132as the second fuel132enters the second fuel injector140. The controller148receives the pressures and determines the differential pressure between the pressures. Once the differential pressure is at or below a value, then the controller148will issue the injector signal168to open the second fuel injector140. For example, the pressure of the compressed intake air118may be around 20 psi to 22 psi, while the pressure of the second fuel132prior to the second fuel injector140may be from 100 psi to 200 psi, indicating a positive differential pressure of around 80 psi as measured by the pressure of the second fuel132prior to the second fuel injector140minus the pressure of the compressed intake air118. Once the pressure of the second fuel132prior to the second fuel injector140is reduced to be at or below the pressure of the compressed intake air118, the differential pressure is zero or a negative value, meaning that, upon opening the second fuel injector140, the compressed intake air118will flow into the second fuel injector140to purge the second fuel132.

The differential pressure between the second fuel132prior to the second fuel injector140and the compressed intake air118can be used by the controller148to determine when to open the second fuel injector140, as discussed above. However, there may be other conditions associated with the internal combustion engine102that may also affect whether or not the controller148opens the second fuel injector140. For example, the controller148may use the operational condition of the second fuel pump142as an indication that a purge operation should proceed. The controller148can receive an indication that the second fuel pump142has ceased operation or has shutdown unexpectedly. This may indicate a fault condition, requiring a purging of the internal combustion engine system100of the second fuel132in anticipation, for example, of maintenance to be done. In another example, the controller148can receive an engine shutdown signal180indicating that the internal combustion engine102has or will commence shutting down. The shutdown signal180causes the controller148to turn off the second fuel pump142to commence reducing the pressure of the second fuel132prior to the second fuel injector140. The timing of the controller148opening and closing the intake valve124and the second fuel injector140is described in more detail inFIG.3.

FIG.3is a timing diagram300that illustrates an example purge process timing, in accordance with various examples of the presently disclosed subject matter. During a purge process, it may be desirable to have the second fuel injector140closed during an air intake cycle of the internal combustion engine102while the purge is occurring. This may be desirable for several reasons. For example, if the second fuel injector140is open during an air intake cycle, meaning the intake valve124is open to allow the compressed intake air118to flow into the cylinder104, a portion of the compressed intake air118may flow into the open second fuel injector140rather than the cylinder104, reducing the amount of the compressed intake air118available for combustion.

Although a purge event is detected by the controller148at time B, because the intake cycle occurs from time A to time C, the controller148does not open the second fuel injector140. It should be noted that when the second fuel132is being used, the controller148would open the second fuel injector140during the intake cycle. However, during a purge operation, the second fuel132would not be used, and thus, the second fuel injector140would remain closed. Further, even after the air intake cycle is completed at time C, meaning the intake valve124is closed, the controller148still maintains the second fuel injector140because the differential pressure between the second fuel132and the compressed intake air118is above a certain value, as discussed above inFIG.1. At time D, the controller148detects that the differential pressure between the second fuel132and the compressed intake air118is at or below a value, and therefore, the controller148causes the second fuel injector140to open, allowing the compressed intake air118to enter the second fuel injector140, purging the second fuel132. The controller148maintains the second fuel injector140open until time E, where the exhaust cycle completes, meaning that the cycle returns to the air intake cycle. The controller148may close the second fuel injector140before time E if the purge is complete. Because the air intake cycle causes the air intake valve124to open, the controller148closes the second fuel injector140. The process by which the controller148opens and closes the second fuel injector140based on engine conditions is illustrated in more detail inFIG.4.

FIG.4illustrates a method400for operating the internal combustion engine102in which the controller148opens and closes the second fuel injector140, in accordance with various examples of the presently disclosed subject matter. The method400and other processes described herein are illustrated as example flow graphs, each operation of which may represent a sequence of operations that can be implemented in hardware, software, or a combination thereof. In the context of software, the operations represent computer-executable instructions stored on one or more tangible computer-readable storage media that, when executed by one or more processors, perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures, and the like that perform particular functions or implement particular abstract data types. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described operations can be combined in any order and/or in parallel to implement the processes.

The method400commences at step402, where the controller148receives a purge event notice. A purge event notice is information provided to the controller148informing the controller148to commence purge operations. Examples of purge event notices are described inFIG.1. For example, the controller148can receive the engine shutdown signal180indicating that the internal combustion engine102has or will commence shutting down, indicating a potential purge operation is to be completed by the controller148. In another example, the controller148may use the operational condition of the second fuel pump142as an indication that a purge operation should proceed. The controller148can receive an indication that the second fuel pump142has ceased operation or has shutdown unexpectedly. This may indicate a fault condition, requiring a purging of the internal combustion engine system100of the second fuel132in anticipation, for example, of maintenance to be done.

At step404, the controller148checks to see if the air intake valve124is closed. As discussed above, to commence a purge operation, the controller148generally checks for two conditions of the engine. The first condition is whether or not the air intake valve124is open. The reason is that while the air intake valve124is open, the internal combustion engine102is in the air intake cycle. If a purge operation commences during this cycle, the internal combustion engine102may not receive a desired or required amount of air for combustion because some of the air may be diverted through the second fuel injector140. Thus, to reduce the effect on the operating conditions of the internal combustion engine102, the controller148may not open the second fuel injector140. It should be noted, however, that in some conditions, the controller148may maintain the second fuel injector open140even during the air intake cycle. Therefore, the presently disclosed subject matter does not require that the air intake valve124be closed during a purge operation. This can be especially true if the compressed intake air118is of sufficient volume to provide both the air for combustion and the air for the purge operation.

At step406, if the controller148determines that the air intake valve124is not closed (step404: No), the controller148maintains the second fuel injector140closed. However, as noted above, in some examples, the method400may proceed with the air intake valve124opened.

At step408, if the controller148determines that the air intake valve124is closed (step404: Yes), the controller148determines if the differential pressure between the second fuel132and the compressed intake air118is at or below a value. As noted above, in some examples, if the differential pressure is above a value, the second fuel132may still be pumped into the internal combustion engine102, preventing the commencement of a purge operation. In order for the compressed air intake to flow into the second fuel injector to purge, the pressure of the second fuel should be lower than the compressed air intake.

At step406, if the controller148determines that the differential pressure between the second fuel132and the compressed intake air118is above a value (step408: No), the controller148maintains the second fuel injector140closed.

At step410, if the controller148determines that the differential pressure between the second fuel132and the compressed intake air118is at or below a value (step408: Yes), the controller opens the second fuel injector140to allow the compressed intake air118to move into the second fuel injector140, pushing the second fuel back into the second fuel tank.

At step412, the controller148determines if the purge operation is complete. In some examples, the controller148can determine that the second fuel injector140has been open for a period of time previously determine sufficient to provide for a purge operation. The presently disclosed subject matter is not limited to any specific technology used by the controller148to determine when a purge operation is complete.

At step404, the controller148determines that the purge operation is not complete (step412: No) and determines if the air intake valve is open. At step406, the controller148determines that the purge operation is complete (step412: Yes) and cause the second fuel injector140to close, ceasing the purge operation. In some examples, once the purge operation is complete, the controller148may isolate the second fuel132from the internal combustion engine102by closing the second fuel cutoff valve144to fluidically disconnect the second fuel132from the internal combustion engine102.

FIG.5depicts a component level view of the controller148for use with the systems and methods described herein, in accordance with various examples of the presently disclosed subject matter. The controller148could be any device capable of providing the functionality associated with the systems and methods described herein. The controller148can comprise several components to execute the above-mentioned functions. The controller148may be comprised of hardware, software, or various combinations thereof. As discussed below, the controller148can comprise memory502including an operating system (OS)504and one or more standard applications506.

The controller148can also comprise one or more processors510and one or more of removable storage512, non-removable storage514, transceiver(s)516, output device(s)518, and input device(s)520. In various implementations, the memory502can be volatile (such as random access memory (RAM)), non-volatile (such as read only memory (ROM), flash memory, etc.), or some combination of the two. The memory502can include data and can be stored on a remote server or a cloud of servers accessible by the controller148.

The memory502can also include the OS504. The OS504varies depending on the manufacturer of the controller148. The OS504contains the modules and software that support basic functions of the controller148, such as scheduling tasks, executing applications, and controlling peripherals. The OS504can also enable the controller148to send and retrieve other data and perform other functions, such as transmitting control signals using the transceivers516and/or output devices518and receiving signals using the input devices520.

The controller148can also comprise one or more processors510. In some implementations, the processor(s)510can be one or more central processing units (CPUs), graphics processing units (GPUs), both CPU and GPU, or any other combinations and numbers of processing units. The controller148may also include additional data storage devices (removable and/or non-removable) such as, for example, magnetic disks, optical disks, or tape. Such additional storage is illustrated inFIG.5by removable storage512and non-removable storage514.

Non-transitory computer-readable media may include volatile and nonvolatile, removable and non-removable tangible, physical media implemented in technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. The memory502, removable storage512, and non-removable storage514are all examples of non-transitory computer-readable media. Non-transitory computer-readable media include, but are not limited to, RAM, ROM, electronically erasable programmable ROM (EEPROM), flash memory or other memory technology, compact disc ROM (CD-ROM), digital versatile discs (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other tangible, physical medium which can be used to store the desired information, which can be accessed by the controller148. Any such non-transitory computer-readable media may be part of the controller148or may be a separate database, databank, remote server, or cloud-based server.

In some implementations, the transceiver(s)516include any transceivers known in the art. In some examples, the transceiver(s)516can include wireless modem(s) to facilitate wireless connectivity with other components (e.g., between the controller148and a wireless modem that is a gateway to the Internet), the Internet, and/or an intranet. Specifically, the transceiver(s)516can include one or more transceivers that can enable the controller148to send and receive data. It should be noted that although communications between the controller148and other components may be illustrated with lines, the communications may be wired or wireless. Thus, the transceiver(s)516can include multiple single-channel transceivers or a multi-frequency, multi-channel transceiver to enable the controller148to send and receive video calls, audio calls, instructions, signals, messaging, and the like. The transceiver(s)516can enable the controller148to connect to multiple networks including, but not limited to 2G, 3G, 4G, 5G, and Wi-Fi networks. The transceiver(s)516can also include one or more transceivers to enable the controller148to connect to future (e.g., 6G) networks, Internet-of-Things (IoT), machine-to machine (M2M), and other current and future networks.

The transceiver(s)516may also include one or more radio transceivers that perform the function of transmitting and receiving radio frequency communications via an antenna (e.g., Wi-Fi or Bluetooth®). In other examples, the transceiver(s)516may include wired communication components, such as a wired modem or Ethernet port, for communicating via one or more wired networks. The transceiver(s)516can enable the controller148to facilitate audio and video calls, download files, access web applications, and provide other communications associated with the systems and methods, described above.

In some implementations, the output device(s)518include any output devices known in the art, such as a display (e.g., a liquid crystal or thin-film transistor (TFT) display), a touchscreen, speakers, a vibrating mechanism, or a tactile feedback mechanism. Thus, the output device(s) can include a screen or display. The output device(s)518can also include speakers, or similar devices, to play sounds or ringtones when an audio call or video call is received. Output device(s)518can also include ports for one or more peripheral devices, such as headphones, peripheral speakers, or a peripheral display.

In various implementations, input device(s)520include any input devices known in the art. For example, the input device(s)520may include a camera, a microphone, or a keyboard/keypad. The input device(s)520can include a touch-sensitive display or a keyboard to enable users to enter data and make requests and receive responses via web applications (e.g., in a web browser), make audio and video calls, and use the standard applications506, among other things. A touch-sensitive display or keyboard/keypad may be a standard push button alphanumeric multi-key keyboard (such as a conventional QWERTY keyboard), virtual controls on a touchscreen, or one or more other types of keys or buttons, and may also include a joystick, wheel, and/or designated navigation buttons, or the like. A touch sensitive display can act as both an input device520and an output device518.

INDUSTRIAL APPLICABILITY

The present disclosure relates generally to purging a fuel from one or more parts of an engine. In various uses, it may be required or desired to remove at least a portion of a fuel from an engine for various reasons. For example, the fuel may be corrosive, whereby allowing the fuel to remain in contact with various parts of an engine may degrade the engine parts. In another example, the fuel may be a safety hazard that, if left within the engine, can endanger personnel using the engine. In engines that a purge operation is to be used, a nitrogen source may purge a portion of the engine, while leaving the fuel within the remaining portions of the engine. Thus, in various examples of the presently disclosed subject matter, the use of the air that is used by the engine during operation can purge the engine more proximate to the cylinders than what may be achievable using a separate air source. Further, using systems and components already installed on the engine, such as a turbocharger, a separate source of high-pressure gas may not be needed in order to achieve a purge operation. In some examples, using previously installed engine components can reduce the weight of the engine and reduce costs.

Unless explicitly excluded, the use of the singular to describe a component, structure, or operation does not exclude the use of plural such components, structures, or operations or their equivalents. As used herein, the word “or” refers to any possible permutation of a set of items. For example, the phrase “A, B, or C” refers to at least one of A, B, C, or any combination thereof, such as any of: A; B; C; A and B; A and C; B and C; A, B, and C; or multiple of any item such as A and A; B, B, and C; A, A, B, C, and C; etc.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems, and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.