Patent Application
20150315990
The present disclosure is directed to a system and method for improving the operating efficiency and/or performance of a diesel engine. More specifically, the present disclosure is directed to a system including injection nozzles configured to inject fuel additives into a combustion air intake system of a diesel engine and a controller for controlling the amount of additives injected.
The illustrative diesel engine 10 includes a combustion air intake system including an air intake 14, a supercharger (for example, a turbo-supercharger or turbocharger) 16, and an intake manifold 18. The air intake 14 provides combustion air from the environment to the supercharger 16. The supercharger 16 pressurizes the combustion air and provides it to the intake manifold 18. The intake manifold 18 distributes the combustion air to the individual cylinders 20 of the diesel engine 10 via a combustion air intake port and valve(s). The diesel engine 10 may include any number of cylinders, for example without limitation, four, six, eight, or sixteen cylinders. Only one cylinder 20 is shown in
The illustrative diesel engine 10 also includes a fuel system including a fuel injector 24 for each cylinder 20 and a fuel supply 22 providing fuel to each fuel injector. The fuel system selectively provides diesel fuel or another suitable fuel from the fuel supply 22 to each cylinder 20 of the diesel engine 10 via the corresponding fuel injector 24. The fuel and combustion air are combusted in the cylinder. An exhaust system 26 receives exhaust gases from the cylinder 20 via an exhaust valve and port and carries them to the environment and/or an after-treatment system. In embodiments where the supercharger 16 is a turbo-supercharger, the exhaust system 26 may be connected to the turbine side thereof to enable the exhaust gases to drive the impeller thereof.
The illustrative diesel engine 10 may be equipped with sensors, for example, without limitation, an ambient air temperature sensor 28, an intake manifold pressure sensor 30, an engine speed sensor (tachometer) 32, an exhaust temperature sensor 34, a coolant temperature sensor 62, and an altitude or ambient barometric pressure sensor (not shown). Such sensors would be configured to sense the respective engine and/or environmental parameters and provide an output signal indicative of same for use by an engine management system, the illustrative system 12, and/or other components.
The illustrative system 12 includes one or more additive subsystems for selectively providing one or more fuel additives to the combustion air intake system of the diesel engine 10. Each additive subsystem may include an additive tank, an additive injector, and an additive conduit in fluid communication with the respective additive tank and additive injector for conveying the additive from the additive tank to the additive injector. An additive isolation valve may be provided, for example, in the additive conduit to isolate the additive tank from the additive injector. The additive isolation valve may be equipped with any suitable form of operator, for example, without limitation, a manual operator, a solenoid operator, an electric operator, or an air operator. The additive isolation valve, where provided, typically would be located at the respective additive tank or in the fluid conduit relatively near the additive tank. Each additive subsystem may be provided with one or more sensors for detecting the respective subsystem tank fill level and/or the respective additive subsystem pressure at the additive tank and/or the additive injector(s) and/or there between, for example, in the additive conduit.
The ether subsystem shown in
The methanol subsystem shown in
The LP subsystem shown in
The additive subsystems shown in
In an embodiment including two additive injectors per additive subsystem, a first of the additive injectors (sometimes referred to herein as a “stage 1” injector) could be configured to inject the additive at a first flow rate and a second of the additive injectors (sometimes referred to herein as a “stage 2” injector) could be configured to inject the additive at a second flow rate, with other relevant parameters, for example, additive pressure and temperature, being equal. Such first and second additive injectors could be independently controlled such that the additive could be injected at first flow rate when the first additive injector is valved in (or “on”) and the second additive injector is valved out (or “off”). The additive could be injected at a second flow rate when the second additive injector is “on” and the first additive injector is “off.” The additive could be injected at a third flow rate when both the first and second additive injectors are “on.” Thus, three different additive flow rates can be provided for using two additive injectors, each having different flow characteristics.
Similarly, seven different additive flow rates could be provided for using three additive injectors, each having different flow characteristics, and so on.
Each additive injector 40, 42, 44 may include an injection valve and an injection nozzle (the injection nozzles may sometimes be referred to herein as “atomizers”), the injection nozzle having an inlet and an outlet (or orifice). The injection valve and injection nozzle could be separate structures, or they could be combined into a unitary structure.
The LP injection nozzle 44B orifice sizes may vary based on engine displacement and whether used as a stage 1 or stage 2 (or other stage) nozzle. In illustrative embodiments, the LP injection nozzle orifices may be generally circular orifices sized as set forth in Table 1 below.
The orifice sizes set forth in Table 1 are illustrative only and could vary for a given engine displacement as well as for engines of different displacements. Also, the orifices could have shapes other than generally circular.
The ether injection nozzle 40B may be similar to the LP injector nozzle 44B, although it may have a different orifice size and/or shape.
The methanol injection nozzle 42B may be similar to the LP injection nozzle 44B, although it may have a different orifice size and/or shape. For example,
The whisper cut 82 may be shaped to promote atomization of methanol injected there through regardless of the cross-sectional area of the opening defined thereby. Typically, the whisper cut 82 would comprise a narrow slit in the sidewall of the methanol injection nozzle 42B near the outlet end 90 thereof. In an embodiment, the whisper cut has a circumferential length of about 1/16 inch around the circumference of the body of the methanol injector nozzle proximate its outlet end 90, a height of about 0.002 inches, and a surface area of about 1.25×10−4 square inches. A whisper cut of this size may allow for a methanol flow rate of about 0.216 cc (cubic centimeter) per second at a methanol pressure of about 200 psi. The foregoing whisper cut sizing and configuration is illustrative. The whisper cut 82 may be sized larger or smaller and shaped differently than described above as may be desired for a particular application. For example, the whisper cut may be longer, shorter, wider, and/or narrower. Also, one or more additional whisper cuts 82 of the same or different size and/or shape may be provided on the methanol injection nozzle 42B as may be desired for a particular application. The whisper cut 82 is shown in
Further, the orifice size (and/or whisper cut size) of any stage 1 injection nozzle may be different from the orifice size (and/or whisper cut size) of any stage 2 injector injection nozzles. Any or all of the injection nozzles may be marked with or otherwise include a flow direction arrow 84 signifying the intended additive flow direction through the nozzle.
The additive injection valves 40A, 42A, 44A may be provided with remotely controlled powered operators, for example, solenoid operators. Alternatively, they may be provided with other forms of powered operators, for example, those described above in connection with the additive isolation valves, or they may be manually operated.
The system 12 also includes an additive injection module 58. The additive injection module 58 is configured for fluid communication with the additive subsystems and the diesel engine combustion air intake system, and it functions as an interface between the additive subsystems and the diesel engine combustion air intake system. In the illustrative system 12 shown in
In an illustrative embodiment, as shown in
The additive injection module shown in
The additive injection module 58 may be connected to the supercharger 16 and the intake manifold 18 using conventional or other intake air conduits or boots. For example, a free end of a boot connecting the supercharger 16 to the additive injection module 60 could be slipped over the inlet side flange 62 and over the adjacent portion of the body 60 and secured thereto using a conventional hose clamp or other suitable means. Similarly, a free end of a boot connecting the intake manifold 18 to the additive injection module 60 could be slipped over the outlet side flange 64 and over the adjacent portion of the body 60 and secured thereto in a similar manner.
The illustrative system 12 shown in
The algorithm may involve the use of look-up tables, for example, without limitation, the look-up tables shown in
The LP look up table of
The injection stages set forth in the methanol and LP look up tables are illustrative and not limiting. They could be established as a function of engine size (or displacement), boost pressure, altitude (ambient barometric pressure), ambient temperature, coolant temperature, engine RPM, and/or other parameters.
A look up table could be provided for the ether sub-system in a similar manner.
In an embodiment, the controller 60 could be provided with a software and/or hardware based algorithm that determines a desired additive flow rate based on any or all of the sensed parameters described herein, as well as engine size and/or other factors. Data sampling and processing could be performed at any desired interval to support the operation of the algorithm and the system 12.
Each additive subsystem could be configured to provide additional additive injection stages, for example, by providing additional additive injectors, as discussed above.
In an illustrative embodiment, methanol may be injected, for example, if the controller, based upon input received from one or more of the foregoing sensors, for example, exhaust gas temperature and/or intake manifold pressure, determines that engine combustion temperature exceeds a predetermined threshold. LP may be injected, for example, if the controller, based upon input received from one or more of the foregoing sensors, for example, engine rpm and/or intake manifold pressure determines that engine combustion temperature falls below a predetermined threshold. Methanol and/or LP injection may be based upon other parameters, as well, for example, engine load as might be determined based on one or more of intake manifold pressure and engine rpm.
As suggested above, the ether subsystem may operate at a pressure of about 20-180 psi or a lesser or greater pressure. The LP subsystem may operate at a pressure of about 50-180 psi or a lesser or greater pressure. The ether and LP subsystem operating pressures may be achieved by charging the ether and LP tanks to pressures at least as great as the desired operating pressures. In an embodiment, either or both of the ether and LP subsystems could include an additive pressure booster pump to boost the additive pressure at the additive injector, for example, to a higher pressure than the corresponding additive tank pressure. For example, the LP pump 62 may be provided in the LP subsystem, as discussed above, to boost the LP supply pressure from the LP tank 38 to the LP injectors into this range, as may be necessary or desired. The methanol subsystem may operate at a pressure of about 170-200 psi or a lower or greater pressure. The methanol pump 60 may be provided in the methanol subsystem, as discussed above, to achieve the foregoing methanol subsystem operating pressure. Filters may be provided in connection with any or all of the additive subsystems to filter the respective additive at any point prior to injection. Pressure regulators may be provided in connection with each additive subsystem to regulate the respective additive subsystem's liquid injection and/or operating pressure.
Sensors monitoring the foregoing additive subsystem operating pressures could be configured to trigger an alarm or a shutdown of the overall system 12 or any additive subsystem thereof if any or all of the additive subsystem operating pressures or levels are outside predetermined parameters.
The system 12 could include a control panel and/or display for controlling and/or monitoring the system.
As suggested above, the system 12 could be used on a diesel engine truck or tractor. In such an embodiment, the LP tank 38 could be located on the truck's frame, on the body behind the operator's cab or sleeper, or elsewhere on the vehicle. The methanol tank 36 could be located under the engine hood or elsewhere on the vehicle. The ether tank 34 similarly could be located under the engine hood or elsewhere on the vehicle. The tank locations could be determined as a function of environmental conditions in the area surrounding the tanks and the space required to accommodate the tanks. In an illustrative embodiment, the tank locations could be selected so that the additive conduits need not be unnecessarily long. The additive tanks typically would be sized to allow extended operation of the diesel engine and system 12 in terms of mileage, time (for example, engine-hours), and/or other parameters. For example, the ether tank might be sized to support a specified number of engine cold starts without replenishment. The methanol and LP tanks might be sized to permit operation of the system 12 for a duration similar to that supported by the engine's diesel or other primary fuel tanks.
In an illustrative embodiment, the foregoing additives are stored and injected in liquid form. The additives may be atomized or vaporized upon injection into the additive injection module 58. A phase change/expansion may occur post-injection, for example, in the additive injection module 58 and/or intake manifold 18.
The system 12 may be operated in conjunction with the operation of the diesel engine 10 by selectively opening and closing the various additive injection valves. The ether injection valve 40A typically would be opened to facilitate starting the engine 10 when the engine coolant and/or ambient air temperatures are below predetermined thresholds. The ether injection valve 40A could then be closed immediately upon engine start up or once the engine has achieved a stable running condition. The ether injection valve 40A could be opened and closed manually by an operator or automatically based on signals provided thereto by the controller.
The methanol and/or LP injection valves 42A, 44A could be opened and closed manually or automatically by the controller as dictated by the look up tables, the algorithm running on the controller, or otherwise. The quantity and timing of methanol injection and/or LP injection may be selected to control combustion temperatures, and may thereby improve the emissions performance of the diesel engine. Also, the quantity and timing of LP injection may be selected to improve the combustion of the diesel fuel or other fuel provided by the fuel system, and may thereby improve the operating efficiency, power, and/or emissions performance of the diesel engine.
The diesel engine 10 may be operated conventionally with the system 12 or a portion or portions thereof turned off or otherwise disabled (for example, as a result of depletion of any or all of the additives).
The embodiments shown and described herein are illustrative and not limiting. One skilled in the art would recognize that features shown in connection one embodiment could be combined with features of another embodiment and that aspects of the embodiments shown and discussed herein could be modified without departure from the scope of the appended claims.
This application claims benefit of U.S. Provisional Patent Application No. 61/986,493, filed on Apr. 30, 2014, and incorporates by reference the disclosure thereof in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61986493 | Apr 2014 | US |
