DIESEL ENGINE

Abstract

An engine (10) comprising a drain system (80) for removing the fuel-filter-separated water into the engine's exhaust line (61). The fuel-filter-removed water can be directly introduced into the exhaust line (61), and/or it can be directly introduced into a hydrocarbon-dosing line (71) that later merges with the exhaust line (61). A control system (90) can control the fuel-filter-removed-water introduction, such as by adjustment of a valve (84) in the drain line (83), the system (90) and can time such introduction so as to not disturb engine operation.

Description

BACKGROUND

A diesel engine can comprise a fuel system wherein a fuel line extends from a fuel tank to an injection rail adjacent or within the combustion chamber. A fuel filter is usually provided somewhere in the fuel line to remove water from the fuel upstream of the combustion chamber. (See e.g., U.S. Pat. No. 7,147,110.) The fuel-filter-removed water can collect in a sump situated below the filter, and the engine can be provided with a drain system for draining the water from the sump.

SUMMARY

A drain system is provided for introducing fuel-filter-removed water into an exhaust line, whereby it exits an engine through the exhaust pipe. The fuel-filter-removed water can be directly introduced into the exhaust line, and/or it can be directly introduced into a hydrocarbon-dosing line that connects downstream of the exhaust line. In either or any case, the fuel-filter-removed water does not have to be manually drained by an operator, the fuel-filter-removed water is not drained onto the ground, and the fuel-filter-removed water is not returned to the fuel tank.

DRAWINGS

FIGS. 1-4 are each a schematic diagram of an engine wherein a hydrocarbon dosing system receives fuel from a location upstream of fuel injection.

FIG. 5 is a schematic diagram of an engine wherein a hydrocarbon dosing system receives fuel from a location downstream of fuel injection.

FIGS. 6A-6C are schematic diagrams of fuel-filter-removed water being directly introduced into the exhaust line.

FIGS. 6D-6F are schematic diagrams of some pumping devices to aid introduction of the fuel-filter-removed water into the exhaust line.

FIGS. 7A-7B are schematic diagrams of fuel-filter-removed water being indirectly introduced into the exhaust line via a hydrocarbon-dosing line.

FIG. 8 is a schematic diagram of an engine control system.

DESCRIPTION

An engine 10, such as the diesel engine schematically shown in FIG. 1, can comprise a combustion system (or chamber) 20, a fuel system 40, an air system 50, and an exhaust system 60.

The combustion chamber 20 can comprise an engine block 21 having multiple (e.g., four) cylinders 22 and pistons 23 mounted for linear motion relative thereto. During operation of the engine 10, each piston 23 repeatedly travels through an intake stroke, a compression stroke, a power stroke, and an exhaust stroke. Each cylinder 22 has an associated air-intake valve 24 that remains closed except during the intake stroke, and an associated exhaust valve 25 that remains closed except during the exhaust stroke. The pistons 23 are connected to a crankshaft 26 that translates the linear motion produced during a power stroke into rotational movement.

The fuel system 40 can comprise a fuel line 41 extending from a fuel tank 42, through a fuel pump 43, through a fuel filter 44, and to a fuel rail 45 within the combustion chamber 20 that feeds fuel injectors 47. A primary role of the fuel filter 44 can be removing water and contaminants from the fuel upstream of the fuel rail 45 and/or combustion chamber 44. The fuel rail 45 holds the pump-pressurized fuel so that the fuel injectors 47 can inject of fuel into each cylinder 22 at the appropriate point in the corresponding piston's stroke cycle (e.g., at the beginning of each power stroke). The fuel pump 43, or another high pressure fuel pump, can instead or alternatively be positioned between the fuel filter 44 and the fuel rail 45.

The air system 50 comprises an air line 51 extending from an intake pipe 52 to an entrance manifold 53 into the combustion chamber 20. The pipe 52 typically intakes ambient (or near ambient) air at atmospheric pressure and weather-dependent temperature. The air line 51 can include a filter 54, a compressor 55, and a throttle 56. A flow meter 57 can be installed in the air line 51 (e.g., near the inlet pipe 52) to measure air intake.

The exhaust system 60 can comprise an exhaust line 61 extending from an exit manifold 62 (that communicates with the combustion chamber 20 when an exhaust valve 25 is open) to an exhaust pipe 63. The illustrated engine 10 has a turbocharger design, with a turbine 64 in the exhaust line 61 that lowers exhaust pressure and simultaneously turns the air compressor 55. The exhaust system 60 can further comprise a recirculation line 65 back to the air line 51 and a valve 66 therein to adjust recirculation flow.

The exhaust pipe 63 typically exhausts to the environment, whereby the line 61 can include a pretreatment and/or anti-pollution device. This device can include, for example, an oxidation catalyst 67 and a particulate filter 68. The catalyst 67 converts carbon monoxide pollutants into carbon dioxide, and the filter 68 captures carbon particles still suspended in the catalyst-converted exhaust gas.

The engine 10 can further comprise a hydrocarbon-dosing system 70 for introducing fuel (i.e., hydrocarbon) to the exhaust line 61. Hydrocarbon-dosing can be done, for example, to regenerate the filter 68, by raising the exhaust temperature above the incineration temperature of potentially-clogging carbon particles. Additionally or alternatively, hydrocarbon-dosing can be done to enhance the performance of the catalyst 67 (or other pretreatment or pollution-preventing device), when the engine 10 is running lean.

The hydrocarbon-dosing system 70 can receive fuel from a location upstream of fuel injection (and thus prior to the fuel leaving the fuel line 41 and entering the combustion chamber 20). For example, in FIG. 1, the system 70 comprises a dosing line 71 extending from the fuel tank 42. In FIG. 2, the dosing line 71 extends from the fuel line 41 at the discharge side of the fuel pump 44. In FIG. 3, the dosing line 71 extends from the fuel line 41 downstream of the filter 44. In FIG. 4, the dosing line 71 extends from the fuel rail 45 (prior to it being injected by the switches 47). When the system 70 includes a dosing line 71, it can also include a valve 72 to control flow therethrough.

The hydrocarbon-dosing system 70 can additionally or alternatively receive fuel from a location downstream of fuel injection. Specifically, for example, the fuel injectors 47 can be used to also inject hydrocarbons into the exhaust gas prior to it exiting into the manifold 62. With in-cylinder dosing, for example, fuel is injected into the cylinder 22 during the exhaust stroke of the piston 23. As shown schematically in FIG. 5, this results in the fuel system 40 and the hydrocarbon-dosing system 70 using the same equipment and components, without the need for a separate dosing line 71 or valve 72.

The engine 10 can further comprise a drain system 80 for draining fuel-filter-removed water from a sump 81 associated with (e.g., positioned below) the fuel filter 44 in the fuel line 44. A level indicator 82 (or other water-quantity sensor) can be used to monitor the amount of water within the sump 81.

The drain system 80 can include a drain line 83 extending from the sump 81 and a valve 84 for opening/closing this drain line 83. The drain line 83 is routed so that the fuel-filter-removed water eventually enters the exhaust line 61 and joins with the exhaust gas traveling therethrough. To this end, the drain line 82 can be directly plumbed to the exhaust line (61), and/or it can be routed through a dosing line 72.

The drain line 82 is schematically shown connected to the exhaust line 61 in FIGS. 6A-6C, whereby drain water is introduced directly to the exhaust gas. The drain water can, for example, be introduced downstream of the filter 68 (FIG. 6A), downstream of the turbine 63 and upstream of the catalyst 67 (FIG. 6B), and/or upstream of the turbine 63 (FIG. 6C). In the first scenario (FIG. 6A), the drain water may desirably lower the final exhaust temperature of the engine 10, but it will not pass through the catalyst 67 or filter 68. In the latter two scenarios (FIGS. 6B and 6C), the drain water passes through the anti-pollution devices 6B/6C, but it may lower catalyst inlet temperature which may not be desirable during regeneration efforts. With post-turbine introduction of the drain water (FIGS. 6A and 6B), the exhaust gas is at a significantly lower pressure than with pre-turbine introduction (FIG. 6C).

The pressure of the drain water will probably be less than the pressure of the exhaust line 61 along its various stages. Accordingly, the drain system 80 may comprise a pumping device or means for encouraging the introduction of the fuel-filter-removed water into the exhaust line 61. For example, the drain system 80 can include a dedicated pump 85 for this purpose, as shown schematically in FIG. 6D. Additionally or alternatively, if fuel-filter-removed-water introduction occurs downstream of the turbine 63, it may be possible to take advantage of the exhaust pressure to aid in water induction into the line 61. For example, as shown in FIG. 6E, water-pumping vanes 86 can be turned by the turbocharger drive train (e.g., the turbine 63), and/or, as shown in FIG. 6F, exhaust bleed can be use as the motive fluid in a venturi device 87.

The drain line 82 can additionally or alternatively be plumbed to the hydrocarbon dosing line 71 upstream of its connection to the exhaust line 61, as shown schematically in FIGS. 7A and 7B. In most instances, the hydrocarbon dosing line 71 will be connected to the exhaust line 61 upstream of the catalyst 67, whereby the fuel-filter-removed water will be introduced upstream of the catalyst. In other words, the drain line 82 could essentially be the hydrocarbon dosing line 71, with the water being expelled during normal dosing cycles. This could be accomplished by, for example, the hydrocarbon dosing line 71 being supplied from the bottom of the fuel filter 44, so that any collected water is automatically expelled into the exhaust gas.

The engine 10 can further comprise a system 90 for controlling the operation of the engine 10. The control 90 can comprise, for example, a microcomputer (or a plurality of microcomputers having an input interface 91, a processor 92, and an output interface 93. The input interface 91 can receive engine-operating information through input lines 100, the processor 92 can process this input to determine optimum operating conditions, and the output interface 93 can provide engine-operating instructions through output lines 200.

As shown schematically in FIG. 8, the control system 90 can receive input information regarding crankshaft rotation (input line 125), fuel tank level (input line 142), air intake flow (input line 157), exhaust manifold temperature (input line 162), final exhaust temperature (input line 163), post-turbine exhaust temperature (input line 164), post-catalyst temperature (input line 167), filter pressure drop (input line 168), and/or sump water level (input line 182). Based on some or all of these inputs, the control system 90 can provide operating instructions to the air-intake valves 24 (output line 224), the exhaust valves 25 (output line 225), the fuel pump 43 (output line 243), fuel injectors 47 (output line 247), air throttle 56 (output line 256), recirculation valve 66 (output line 266), dosing valve 72 (output line 272), drain valve 84 (output line 284), drain pump 86 (output line 285), and/or drain venture device 87 (output line 287).

The control system 90 can be used to initiate introduction of fuel-filter-removed water from the sump 81 into the exhaust line 61. The system 90 can, for example, determine that drainage is necessary based on the water level in the sump 81 (via input line 182). The drain valve 72 can be opened via the output line 272 and, if applicable, the drain pump 85 activated and/or the venturi-device valves 87 adjusted via output lines 285/287.

The control system 90 can time introduction of the fuel-filter-removed water so as to not disturb, and perhaps to enhance, engine operation. For example, if water introduction will have a cooling effect, it can be initiated upon sensing (via input line 163) that final exhaust temperature is above a desirable range. Water introduction could be used to enhance catalyst conversion when deemed appropriate by temperature inputs through line 164 and/or line 167. Additionally or alternatively, water introduction could be coordinated with hydrocarbon dosing and correlated with the opening of dosing valve 72 (via output line 272) or fuel dosing fuel injection (via output line 247).

That being said, such elaborate system-control coordination of the drain system 80 with the rest of the engine systems may not be necessary. The control of the drain system 80 could be as simple as metering the sump water into the exhaust line 61 at a predetermined rate and/or preset intervals. Check valves and mechanical thermostats could be used to prevent engine-interrupting issues. Such a simpler incorporation might be desirable if the engine 10 is to be retrofitted with the drain system 80, as it will not require replacement and/or reprogramming of the existing engine control system 90.

If the drain line 82 is also the hydrocarbon dosing line 71 (or vice-a-versa), the draining of fuel-filter-removed water can be controlled by the hydrocarbon-dosing logic of the system 90. For example, if hydrocarbon dosing is needed (e.g., a high pressure drop is sensed across the exhaust filter 68), the drain valve 84 can be opened. As the fuel-filter-removed water is draining through the line 71/82, regeneration may not occur. But the process can be repeated until the drain water is gone (e.g., as measured by sensor 82). The dosing valve 72 can remain closed until water draining is complete (or the fuel injections 47 can delay injecting fuel into the exhaust gas), and thereafter the dosing fuel supplied to cause regeneration of the exhaust filter 68.

One may now appreciate that with the engine 10 and/or the drain system 80, fuel-filter-removed water does not have to be drained manually from the sump 81, the water is not drained onto the ground, and the water is not returned to the fuel tank 42. Although the engine 10, the systems 20, 40, 50, 60, 70, 80, 90, and/or related components, methods, or steps have been shown and described with respect to certain embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In regard to the various functions performed by the above described elements (e.g., components, assemblies, systems, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.

Claims

1. An engine comprising: a combustion chamber;a fuel system comprising a fuel line for supplying fuel from a fuel tank to the combustion chamber and a fuel filter in the fuel line upstream of the combustion chamber, wherein the fuel filter separates water from fuel;an exhaust system comprising an exhaust line for exhausting the combustion chamber and an exhaust pipe that forms an outlet for the exhaust line from the engine to the environment; anda drain system for introducing the water separated by the fuel filter into the exhaust line;wherein the drain system introduces the filter-separated water to the exhaust line downstream of the combustion chamber and upstream of the exhaust pipe.

2. An engine as set forth in claim 1, wherein the drain system introduces fuel-filter-separated water directly to the exhaust line.

3. An engine as set forth in claim 1, wherein the drain system introduces the fuel-filter-separated water indirectly to the exhaust line, by introducing the water to a line upstream of its connection to the exhaust line.

4. An engine as set forth in claim 1, wherein the fuel-filter-separated water is collected in a sump associated with the fuel filter, and wherein a drain line extends from the sump, with a valve for adjusting flow therethrough.

5. An engine as set forth in claim 1, wherein the drain system includes a pumping device to aid introduction of the fuel-filter-removed water to the exhaust line.

6. An engine as set forth in claim 1, wherein the exhaust system comprises an exhaust manifold that receives exhaust gas from the combustion chamber, wherein the exhaust line extends from the exhaust manifold to the exhaust pipe, and wherein the drain system introduces the fuel-filter-removed water to the exhaust line downstream of the exhaust manifold.

7. An engine as set forth in claim 1, wherein the exhaust system comprises a turbine and wherein the drain system introduces the fuel-filter-removed water to the exhaust line downstream of the turbine.

8. An engine as set forth in claim 1, wherein the exhaust system comprises a pollution-preventing device and wherein the drain system introduces the fuel-filter-removed water to the exhaust line upstream of the pollution-preventing device.

9. An engine as set forth in claim 8, wherein the pollution-preventing device includes an oxidation catalyst.

10. An engine as set forth in claim 9, wherein the pollution-preventing device further includes a particulate filter downstream of the oxidation catalyst.

11. An engine as set forth in claim 1, further comprising a hydrocarbon-dosing system that introduces fuel to the exhaust line through a dosing line, and wherein the drain system introduces the fuel-filter-removed water to the dosing line upstream of its connection to the exhaust line.

12. An engine as set forth in claim 11, wherein the exhaust system includes a pollution-preventing device in the exhaust line, and wherein the hydrocarbon-dosing system introduces fuel to the exhaust line upstream of the pollution-preventing device.

13. An engine as set forth in claim 12, wherein the pollution-preventing device comprises an oxidation catalyst.

14. An engine as set forth in claim 11, wherein the hydrocarbon dosing system is supplied from the bottom of the fuel filter whereby the fuel-filter-removed water is expelled into the exhaust during hydrocarbon dosing.

15. An engine as set forth in claim 1, wherein the fuel system comprises fuel injectors that inject fuel to initiate combustion and accomplish piston power strokes, wherein these fuel injectors also inject fuel into exhaust gas to hydrocarbon dose the exhaust gas, and wherein the introduction of the fuel-filter-removed water into the exhaust line is coordinated with the injection of fuel into the exhaust gas.

16. An engine as set forth in claim 1, further comprising a control system having an input interface for receiving engine-operating information, a processor for processing the input information and determining optimum engine operating conditions, and an output panel for providing engine-operating instructions in accordance with the determined optimum engine operating conditions; and wherein the control system controls the introduction of fuel-filter-removed water into the exhaust line based on input engine-operating information.

17. An engine as set forth in claim 16, wherein the control system controls hydrocarbon dosing of exhaust gas in the exhaust line and wherein the fuel-filter-removed-water introduction is coordinated with the hydrocarbon dosing.

18. An engine as set forth in claim 1, wherein the engine is a diesel engine.

19. A drain system for draining fuel-filter-removed water from an engine, said drain system comprising: a sump in which water removed from fuel by a fuel filter collects,a sensor for sensing the amount of water in the sump;a drain line extending from the sump and adapted for connection to an exhaust line,a valve for adjusting the flow of fuel-filter-removed water through the drain line; anda control system receiving input from the sensor and providing output to the valve to control the flow of fuel-filter-removed water through the drain line to the exhaust line.

20. In combination, the drain system set forth in claim 19 and a fuel filter for removing water from fuel in a fuel line, wherein the water removed by the fuel filter collects in the sump.