The present disclosure relates generally to high pressure pumps, and more particularly, to a pump life prediction system for such pumps.
Fuel pumps for internal combustion engines, such as high pressure common rail pumps, may fail due to cavitation damage in the pump. The severity and accumulation rates of cavitation damage may vary based on pump operating conditions. Pumps may fail due to cavitation damage with little advance warning, which may lead to significant and unplanned engine downtime.
U.S. Patent Application Publication No. 2018/0216566, published on Aug. 2, 2018 (“the '566 publication”), describes methods and systems for health assessments of a fuel system including a high pressure fuel pump. The system measures pressure pulses from the pump caused by pistons of the pump pushing fuel out of the pump towards a fuel rail. The system indicates pump degradation if one or more expected pulses are missing and/or if one or more of the pulses are weaker than expected. However, the system of the '566 publication may not adequately predict pump life remaining.
The pump life prediction system of the present disclosure may solve one or more of the problems set forth above and/or other problems in the art. The scope of the current disclosure, however, is defined by the attached claims, and not by the ability to solve any specific problem.
In one aspect, a method for predicting pump life of a pump is disclosed. The method may include: monitoring pump operating conditions; determining a value indicative of cavitation damage based on the pump operating conditions; determining a pump life remaining based on the value; and outputting an indication of the pump life remaining.
In another aspect, a method for predicting pump life of a fuel pump for an engine system having a fuel rail is disclosed. The method may include: monitoring pump flow, pump speed, and rail pressure; determining a value indicative of cavitation damage based on at least one of the pump flow, pump speed, and rail pressure; determining a pump life remaining based value; and outputting an indication of the pump life remaining.
In yet another aspect, a pump life prediction system is disclosed. The system may include: a pump; one or more sensors for measuring pump operating conditions; and a controller configured to: monitor the pump operating conditions; determine a value indicative of cavitation damage based on the pump operating conditions; determine a pump life remaining based on the value; and output an indication of the pump life remaining.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and together with the description, serve to explain the principles of the disclosed embodiments.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. As used herein, the terms “comprises,” “comprising,” “has,” “having,” “includes,” “including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. In this disclosure, unless stated otherwise, relative terms, such as, for example, “about,” “substantially,” and “approximately” are used to indicate a possible variation of ±10% in the stated value.
Fuel system 12 includes a fuel tank 18, a pump 20, and a high pressure common rail 22 in communication with each other via a fuel line 24. Common rail 22 may include one or more fuel injectors 26 for injecting fuel into the cylinders of the engine 14. Pump 20 may be a high pressure pump for providing fuel from tank 18 to common rail 22 at a high pressure. A high pressure pump may include a mechanical pump for compressing and pressurizing fluid (e.g., fuel) to high pressures. As such, pump 20 may include one or more plungers 28, one or more inlet valves 30, and one or more outlet valves 32. Plunger 28 may be controllable to move up and down to draw fuel into pump 20 through valve 30 and push pressurized fuel out of pump 20 through valve 32. Pump 20 may further include a valve 34, such as an inlet metering valve, for ensuring that only a quantity of fuel required by the injectors 26 is provided to rail 22. Valve 34 may be any type of valve, such as a solenoid valve, proportional spool valve, or the like. Accordingly, valve 34 may be controllable to various positions between an open position and a closed position for adjusting a fuel flow rate and metering the quantity of fuel to pump 20, and thus to rail 22 for distribution of the fuel to injectors 26. Fuel system 12 may also include a low pressure pump (not shown), such as a fuel transfer pump, between the fuel tank 18 and pump 20 for generating a flow of fuel from fuel tank 18 to pump 20.
Output indicator 16 may indicate pump life remaining of the pump 20. Output indicator 16 may include a display, a gauge, a light, a speaker, or the like. For example, output indicator 16 may indicate a value (numerical value, percentage, or the like) of pump life remaining of pump 20 and/or may indicate (e.g., via a notification) when pump life remaining of pump 20 decreases below a predetermined threshold (e.g., below 10% pump life remaining). Indicator 16 may be located in an operator cab (not shown) and/or may be located remote from engine system 10. While only a single output indicator 16 is described herein, it is understood that output indicator 16 may include one or more indicators and may include any type of indicator for indicating pump life remaining of pump 20.
Pump life prediction system 100 includes a controller 104, such as an engine control module (ECM), and a sensor system 36 connected to controller 104. Sensor system 36 my include one or more sensors for measuring pump operating conditions, such as pressure sensors, speed sensors, or the like. For example, sensor system 36 may include a rail pressure sensor 38 and an engine speed sensor 40. Rail pressure sensor 38 may be located in rail 22 and may sense a rail pressure. Engine speed sensor 40 may be located at the crankshaft of engine 14 and may sense engine speed. Engine speed sensor 40 may be located at any location of engine 14, such as, for example, a crank pulley, the flywheel, a camshaft, or on the crankshaft. It is understood that sensors 38, 40 may include any type of sensors such as resistive sensors, inductive sensors, capacitive sensors, piezoelectric sensors, optical sensors, micro electro-mechanical system sensors, or the like. Further, sensor system 36 may include any number and/or combination of sensors as necessary. Controller 104 may also be in communication with valve 34 for controlling a position of valve 34 and with injectors 26 for regulating and controlling fuel injection into the cylinders of engine 14.
Controller 104 may embody a single microprocessor or multiple microprocessors that may include means for predicting pump life of pump 20 for engine system 10. For example, controller 104 may include a memory, a secondary storage device, a processor, such as a central processing unit or any other means for accomplishing a task consistent with the present disclosure. The memory or secondary storage device associated with controller 104 may store data and/or software routines that may assist controller 104 in performing its functions, such as the functions of methods 400 and 500 of
Controller 104 may also include stored and/or derived values 116 for use by module 108. For example, the stored and/or derived values 116 may include pump speed, pump life remaining, and one or more cavitation damage look-up tables or maps. Pump speed may be derived from a virtual pump speed sensor. For example, engine speed (e.g., crankshaft speed) may correspond to a speed of pump 20 and controller 104 may derive pump speed from engine speed signal 112. Pump speed may also be derived from other sources, such as other sensors (e.g., physical or virtual sensors) associated directly or indirectly with pump 20. Pump life remaining may include a stored value indicative of pump life remaining of pump 20 that may be decremented as engine system 10, and thus pump 20, operates. The value indicative of pump life remaining of pump 20 may be set for a particular amount of time (e.g., seconds, minutes, hours, etc.) of operation that is based on typical life of a pump. Pump life remaining may include an initial stored full pump life value when the pump is new (e.g., has not yet been operated). Accordingly, the pump life remaining value (e.g., the full pump life value) may be decremented by an amount of time pump 20 is on and operating during normal operation. Thus, the pump life remaining value may be updated as pump 20 is operated and the updated value may be stored by controller 104. In some instances, cavitation damage of pump 20 may reduce pump life, and thus pump life remaining may decrement at a faster rate than during normal operation.
The cavitation damage look-up tables or maps provide values indicative of cavitation damage. An exemplary cavitation damage map 300 is depicted in
The cavitation factors may be dimensionless values that correspond to an amount that cavitation damage in the respective zone effects pump life remaining. For example, cavitation damage may not be present in pump 20 when the operating conditions are in zone 1.0, and thus pump life remaining may decrement by a cavitation factor of 1.0. When the operating conditions are in zones 1.4 or 1.5, cavitation damage may be present in pump 20, and pump life may be reduced. Thus, pump life remaining may decrement at a faster rate when the operating conditions are in zones 1.4 or zone 1.5 (e.g., by a factor of 1.4 or 1.5). It is understood that the cavitation maps may include any number of maps and may include any number of zones corresponding to any cavitation factor value.
Referring again to
The disclosed aspects of the pump life prediction system 100 of the present disclosure may be used in any system having a pump 20 that may be subject to cavitation damage.
With reference to
In step 510, module 108 may update a cavitation damage value. The cavitation damage value may be a stored time value factored by the cavitation factor. For example, module 108 may multiply the cavitation factor (e.g., 1.4) by a cycle time (e.g., the amount of time the pump life module runs through steps 505-510 of method 500). This value may be added to a stored previous cavitation damage value to update the cavitation damage value (step 510). In the exemplary embodiment, the cycle time may be one second and module 108 may update the cavitation damage value by adding 1.4 (e.g., determined by 1.4×1 second) to the stored cavitation damage value. Thus, the cavitation damage value may be an amount of time (e.g., cycle time) factored by an amount that cavitation effects pump life remaining. Module 108 may then store the new cavitation damage value.
To determine pump life remaining based on the value (step 415), in step 515, module 108 may determine pump life remaining based on the cavitation damage value. Pump life remaining is equal to the full pump life minus the cavitation damage value. Thus, pump life remaining may be an amount of time of life remaining for pump 20. Module 108 may cycle method 500 at regular intervals (e.g., 1 second intervals) such that module 108 may determine a duration the pump operating conditions are in each zone of the cavitation damage maps. Thus, pump life remaining may be determined based on the duration the pump operating conditions are in each zone.
To output the indication of pump life remaining (step 420), module 108 may then compare the pump life remaining to a threshold. For example, in step 520, module 108 may determine if pump life remaining is less than a threshold. The threshold may be a predetermined value (e.g., 10% of full pump life remaining) stored by controller 104. If pump life remaining is greater than the threshold (step 520: NO), module 108 may cycle to step 505. If pump life remaining is less than or equal to the threshold (step 520: YES), module 108 may output an indication of pump life remaining (step 525). For example, module 108 may output a signal to output indicator 16 to turn on a light, to output an audible alert on a speaker, or to output an alert on a display indicating a need to replace or repair pump 20.
Pump life prediction system 100 may enable prediction of pump life remaining for pump 20. For example, pump life prediction system 100 may detect reduced pump life due to cavitation damage in pump 20. Accordingly, pump life prediction system 100 may more accurately indicate pump life remaining and proactively alert a user (e.g., operator, technician, etc.) so that the user may repair and/or replace pump 20 prior to failure of pump 20.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system without departing from the scope of the disclosure. Other embodiments of the system will be apparent to those skilled in the art from consideration of the specification and practice of the system disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.
Number | Name | Date | Kind |
---|---|---|---|
20040030524 | Jarrell | Feb 2004 | A1 |
20040167738 | Miller | Aug 2004 | A1 |
20080215255 | Stockner | Sep 2008 | A1 |
20080217421 | Lewis | Sep 2008 | A1 |
20170057667 | Ward | Mar 2017 | A1 |
20170091358 | Zhang | Mar 2017 | A1 |
20180216566 | Taxon | Aug 2018 | A1 |