Patent Application
20160245209
The subject matter disclosed herein relates to knock sensors, and more specifically, to recording signals from knock sensors mounted to large, multi-cylinder reciprocating devices (e.g., combustion engines, compressors, etc.).
Combustion engines typically combust a carbonaceous fuel, such as natural gas, gasoline, diesel, and the like, and use the corresponding expansion of high temperature and pressure gases to apply a force to certain components of the engine, e.g., piston disposed in a cylinder, to move the components over a distance. Each cylinder may include one or more valves that open and close correlative with combustion of the carbonaceous fuel. For example, an intake valve may direct an oxidizer such as air into the cylinder, which is then mixed with fuel and combusted. Combustion fluids, e.g., hot gases, may then be directed to exit the cylinder via an exhaust valve. Accordingly, the carbonaceous fuel is transformed into mechanical motion, useful in driving a load. For example, the load may be a generator that produces electric power.
Knock sensors can be used to monitor multi-cylinder combustion engines. A knock sensor can be mounted to the exterior of an engine cylinder and used to determine whether or not the engine is running properly. Sometimes an operator will have difficulty confirming the knocking detected by the knock sensor. For instance, a knock may be too quiet or otherwise go unnoticed by the operator. Accordingly, there is a need to have a way for operators to confirm the knocking occurrence.
Certain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below.
In a first embodiment, a system includes a controller configured to obtain a signal from a knock sensor coupled to a reciprocating device, analyze the signal to determine a trigger event occurrence based on the signal having an abnormal signature, wherein the abnormal signature is associated with a knocking of the reciprocating device, and generate a first audio file of a first audio recording to store in a memory of the controller, wherein the first audio recording provides an indication of the knocking of the reciprocating device.
A second embodiment includes one or more non-transitory computer-readable media encoding one or more processor-executable routines wherein the one or more routines, when executed by a processor of a controller of a reciprocating device, cause acts to be performed including obtaining a signal from a knock sensor coupled to the reciprocating device, analyzing the signal to determine a trigger event occurrence based on the signal having an abnormal signature, wherein the abnormal signature is associated with a knocking of the reciprocating device, and generating an audio file of an audio recording to store in a memory of the controller, wherein the audio recording provides an indication of the knocking of the reciprocating device.
In a third embodiment, a method includes obtaining a signal from a knock sensor coupled to the reciprocating device, analyzing the signal to determine a trigger event occurrence based on the signal having an abnormal signature, wherein the abnormal signature is associated with a knocking of the reciprocating device, generating an audio file of an audio recording of the controller, wherein the audio recording provides an indication of the knocking of the reciprocating device, and storing the audio file in a look up table on a memory.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
The techniques described herein include the use of one or more knock sensor systems and methods that may detect an undesired knocking condition in a reciprocating device, such as a combustion engine or compressor. When using a knock sensor to monitor a combustion engine, occasionally the knock sensor system detects a knock, such as an abnormal or undesired noise. Rather than ignore and discard the unidentifiable noises, it may be advantageous to save recordings of unidentifiable noises for analysis at a later date or time. For instance, the knock sensor may detect a knocking that is inaudible or goes unnoticed to an operator. In some embodiments, the knock sensor may be used to shut down the engine to avoid damage to the engine. If the engine is shut down and the operator does not hear the knocking detected by the knock sensor, the operator may believe the knock sensor is operating improperly. Accordingly, the present disclosure is directed to a system and method that addresses a need for operators to confirm engine knocking. Further, having a log of characterized identified noises greatly increases the utility of the data set. Accordingly, the recorded noises can be compared and/or stored with other noises in a look up table (e.g., table in a database, excel spreadsheet, or other table stored in memory).
Turning to the drawings,
The system 8 disclosed herein may be adapted for use in stationary applications (e.g., in industrial power generating engines) or in mobile applications (e.g., in cars or aircraft). The engine 10 may be a two-stroke engine, three-stroke engine, four-stroke engine, five-stroke engine, or six-stroke engine. The engine 10 may also include any number of combustion chambers 12, pistons 20, and associated cylinders (e.g., 1-24). For example, in certain embodiments, the system 8 may include a large-scale industrial reciprocating engine having 4, 6, 8, 10, 16, 24 or more pistons 20 reciprocating in cylinders. In some such cases, the cylinders and/or the pistons 20 may have a diameter of between approximately 13.5-34 centimeters (cm). In some embodiments, the cylinders and/or the pistons 20 may have a diameter of between approximately 10-40 cm, 15-25 cm, or about 15 cm. The system 10 may generate power ranging from 10 kW to 10 MW. In some embodiments, the engine 10 may operate at less than approximately 1800 revolutions per minute (RPM). In some embodiments, the engine 10 may operate at less than approximately 2000 RPM, 1900 RPM, 1700 RPM, 1600 RPM, 1500 RPM, 1400 RPM, 1300 RPM, 1200 RPM, 1000 RPM, 900 RPM, or 750 RPM. In some embodiments, the engine 10 may operate between approximately 750-2000 RPM, 900-1800 RPM, or 1000-1600 RPM. In some embodiments, the engine 10 may operate at approximately 1800 RPM, 1500 RPM, 1200 RPM, 1000 RPM, or 900 RPM. Exemplary engines 10 may include General Electric Company's Jenbacher Engines (e.g., Jenbacher Type 2, Type 3, Type 4, Type 6 or J920 FleXtra) or Waukesha Engines (e.g., Waukesha VGF, VHP, APG, 275GL), for example.
The driven power generation system 8 may include one or more knock sensors 23 suitable for detecting engine “knock.” The knock sensor 23 may sense vibrations caused by the engine, such as vibration due to detonation, pre-ignition, and or pinging. The knock sensor 23 is shown communicatively coupled to an engine control unit (ECU) 25. During operations, signals from the knock sensor 23 are communicated to the ECU 25 to determine if knocking conditions (e.g., pinging) exist. The ECU 25 may then adjust certain engine 10 parameters to ameliorate or avoid the knocking conditions. For example, the ECU 25 may adjust ignition timing and/or adjust boost pressure to avoid the knocking. As further described herein, the knock sensor 23 may additionally derive that certain vibrations should be further analyzed and categorized to detect, for example, undesired engine conditions.
As shown, the piston 20 is attached to a crankshaft 54 via a connecting rod 56 and a pin 58. The crankshaft 54 translates the reciprocating linear motion of the piston 24 into a rotating motion. As the piston 20 moves, the crankshaft 54 rotates to power the load 24 (shown in
During operations, when the piston 20 is at the highest point in the cylinder 26 it is in a position called top dead center (TDC). When the piston 20 is at its lowest point in the cylinder 26, it is in a position called bottom dead center (BDC). As the piston 20 moves from top to bottom or from bottom to top, the crankshaft 54 rotates one half of a revolution. Each movement of the piston 20 from top to bottom or from bottom to top is called a stroke, and engine 10 embodiments may include two-stroke engines, three-stroke engines, four-stroke engines, five-stroke engine, six-stroke engines, or more.
During engine 10 operations, a sequence including an intake process, a compression process, a power process, and an exhaust process typically occurs. The intake process enables a combustible mixture, such as fuel and air, to be pulled into the cylinder 26, thus the intake valve 62 is open and the exhaust valve 64 is closed. The compression process compresses the combustible mixture into a smaller space, so both the intake valve 62 and the exhaust valve 64 are closed. The power process ignites the compressed fuel-air mixture, which may include a spark ignition through a spark plug system, and/or a compression ignition through compression heat. The resulting pressure from combustion then forces the piston 20 to BDC. The exhaust process typically returns the piston 20 to TDC while keeping the exhaust valve 64 open. The exhaust process thus expels the spent fuel-air mixture through the exhaust valve 64. It is to be noted that more than one intake valve 62 and exhaust valve 64 may be used per cylinder 26.
The depicted engine 10 also includes a crankshaft sensor 66, the knock sensor 23, and the engine control unit (ECU) 25, which includes a processor 72 and memory 74. The crankshaft sensor 66 senses the position and/or rotational speed of the crankshaft 54. Accordingly, a crank angle or crank timing information may be derived. That is, when monitoring combustion engines, timing is frequently expressed in terms of crankshaft 54 angle. For example, a full cycle of a four stroke engine 10 may be measured as a 720° cycle. The knock sensor 23 may be a Piezo-electric accelerometer, a microelectromechanical system (MEMS) sensor, a Hall effect sensor, and/or any other sensor designed to sense vibration, acceleration, sound, and/or movement.
Because of the percussive nature of the engine 10, the knock sensor 23 may be capable of detecting signatures even when mounted on the exterior of the cylinder 26. However, the knock sensor 23 may be disposed at various locations in or about the cylinder 26. Additionally, in some embodiments, a single knock sensor 23 may be shared, for example, with one or more adjacent cylinders 26. In other embodiments, each cylinder 26 may include one or more knock sensors 23. The crankshaft sensor 66 and the knock sensor 23 are shown in electronic communication with the engine control unit (ECU) 25. The ECU 25 includes a processor 72 and a memory 74. The memory 74 may store computer instructions that may be executed by the processor 72. The ECU 25 monitors and controls operation of the engine 10, for example, by adjusting combustion timing, valve 62, 64, timing, adjusting the delivery of fuel and oxidant (e.g., air), and so on.
Advantageously, the techniques described herein may use the ECU 25 to receive signals (e.g., data) from the crankshaft sensor 66 and the knock sensor 23, and then to create a “noise” signature by plotting the knock sensor 23 signals against the crankshaft 54 position. The ECU 25 may then go through the process of analyzing the data to derive normal (e.g., known and expected noises) and abnormal signatures (e.g., unknown or unexpected noises).
For example,
The knock sensor may detect undesirable, unknown, or unexpected vibrations (e.g., knocking) that an operator may miss or not hear. For instance, the ECU 25 may access a reference signature (e.g., signal or pattern) stored in the memory 74. The ECU 25 may compare the reference signature to the noise signature of the knock sensor 23. For example, if the knock sensor signal amplitude exceeds the reference signal, the ECU 25 may determine that knocking has occurred. As such, it may be desirable to generate an audio file of an audio recording and/or store the audio file in the memory 74 to provide evidence to the operator of the engine 10 knocking. The audio recording may provide an indication to the operator that the engine is knocking. Accordingly, the stored signals may be used as proof of the knocking. Moreover, the signals may be used for further diagnostics discussed below.
The processor 72 of the ECU 25 may be configured to generate signals (e.g., audio signals, data signals, etc.) related to the audio file to output to a flash drive, a workstation (e.g., a display of a workstation), another electronic control unit, or any suitable device for receiving signals related to the audio file. For instance, the audio signals or diagnostic information may be sent over a controller area network (CAN). The ECU 25 may transmit and/or receive messages (e.g., audio recordings) using any suitable wireless or wired protocol. Accordingly, while the processes in
As discussed with respect to
After recording the audio file of the abnormal signature, the audio file may be compared to other audio files associated with abnormal signatures (block 106). For instance, a fingerprint of the audio recording may be used to compare with other fingerprints of audio recordings of abnormal signatures. The fingerprints may be based on different frequencies, amplitudes, or the like. If there are no similar fingerprints in the look up table (block 108), the processor may store the audio file/fingerprint for later characterization (block 110). If there are similar fingerprints found (block 108), the processor 72 may continue by characterizing the abnormal signature and updating the look up table (block 112).
In an embodiment of the present disclosure, if a particular engine has a piston that improperly contacts a portion of the cylinder, the processor 72 may access signals received from the knock sensor associated with that particular cylinder. The processor 72 may then determine if the knock signals are related to an abnormal signature or a normal signature. When the improper contact occurs, the processor 72 may detect a trigger event based on the abnormal signature of the knock sensor. When the improper contact begins (i.e. an abnormal signature is detected), the processor 72 may begin to record an audio recording as evidence of the improper contact. When the improper contact ends (i.e. a normal signature is detected), the processor 72 may stop the audio recording. Various frequencies and amplitudes (i.e. fingerprints) associated with the recording may then be compared to the frequencies and amplitudes of the recordings in a database. If the improper contact has occurred in other cases, the recording may then be associated with the piston improperly contacting the cylinder (i.e. condition). The database may then be updated based on the recording.
Technical effects of the disclosed embodiments relate to recording knocking noises in an engine. More particularly, the engine control unit may generate an audio recording or a file of the recording of knocking in an engine. The audio recording may be output to a display or speakers to provide an operator with evidence of knocking in an engine. The engine control unit may detect a trigger event of an abnormal signature and begin recording a knocking of an engine. The engine control unit may stop recording when the abnormal signature stops. The audio recording can be compared to other audio recordings and put into a table based on characteristics of the audio recording. Then an operator can use the recording and/or diagnose problems in the engine based on the recording.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
