Monitoring mechanical devices for signs of failure is an essential part of equipment maintenance. This is especially true in industry where machines can be operated for very long durations and any failure of the equipment can be very costly.
For example, steam traps are an essential part of steam systems. A steam trap removes condensate (condensed steam) and non-condensable gases from the steam system without allowing steam to escape. Unfortunately, when steam traps fail, steam can escape resulting in wasted energy.
Likewise, bearings are an essential part of machines containing rotating components. The bearings make it easy for the parts to rotate. Unfortunately, when bearings fail, rotating parts in machines can stop turning, causing the equipment to stop operating.
Accordingly, it is desirable to provide new mechanisms for detecting abnormalities in equipment.
Systems, methods, and media for monitoring steam traps for failure are provided.
In some embodiments, systems for monitoring a steam trap for failure are provided, the systems comprising: an energy sensor; and a hardware processor that is coupled to the energy sensor and that is configured to: set a waiting period of time to an initial value; sample first energy output by the steam trap based upon a first signal from the energy sensor; wait the waiting period of time; sample second energy output by the steam trap after waiting the waiting period of time based upon a second signal from the energy sensor; determine whether the second energy output by the steam trap indicates a problem in the steam trap; in response to determining that the second energy output by the steam trap does not indicate a problem in the steam trap, increase the waiting period of time to an increased period of time; and sample third energy output by the steam trap after waiting the increased period of time based upon a third signal from the energy sensor.
In some embodiments, methods of monitoring a steam trap for failure are provided, the methods comprising: setting a waiting period of time to an initial value; sampling first energy output by the steam trap; waiting the waiting period of time; sampling second energy output by the steam trap after waiting the waiting period of time; determining whether the second energy output by the steam trap indicates a problem in the steam trap; in response to determining that the second energy output by the steam trap does not indicate a problem in the steam trap, increasing the waiting period of time to an increased period of time; and sampling third energy output by the steam trap after waiting the increased period of time.
In some embodiments, non-transitory computer-readable media containing computer-executable instructions that, when executed by a processor, cause the processor to perform a method for monitoring a steam trap for failure are provided, the method comprising: setting a waiting period of time to an initial value; sampling first energy output by the steam trap; waiting the waiting period of time; sampling second energy output by the steam trap after waiting the waiting period of time; determining whether the second energy output by the steam trap indicates a problem in the steam trap; in response to determining that the second energy output by the steam trap does not indicate a problem in the steam trap, increasing the waiting period of time to an increased period of time; and sampling third energy output by the steam trap after waiting the increased period of time.
Systems, methods, and media for monitoring steam traps for failure are provided.
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Sensor modules 102 can be any suitable sensor modules, and any suitable number of sensor modules can be used. For example, in some embodiments, sensor modules 102 can be the sensor modules described below in connection with
Communication network 104 can be any suitable communication network and/or combination of communication networks. For example, communication network 104 can be wired and/or wireless, and can include the Internet, telephone networks, cable television networks, mobile phone networks, satellite networks, radio networks, mesh networks, low-power wide-area networks (LPWANs), and/or any other suitable mechanisms for communicating information. More particularly, for example, communication network 104 can include the Senet Network from Senet, Inc. of Portsmouth, N.H. As another example, communication network 104 can include the MachineQ network available from Comcast of Philadelphia, Pa.
Server 106 can be any suitable device for receiving data from sensor modules 102, controlling sensor modules 102, storing the data, processing the data, providing information to a user via user device 108, and/or performing any other suitable functions. Any suitable number of servers can be used, and the functions described here as being performed by the server can be performed across two or more servers, in some embodiments. In some embodiments, server 106 can be a general-purpose computer or a special purpose computer. In some embodiments, server 106 can include, or be connected to, a database.
User device 108 can be any suitable device for accessing server 106 in order to review information from server 106, control settings for the sensor modules, and/or perform any other suitable functions and any suitable number of user devices can be used. In some embodiments, user device 108 can be a general-purpose computer or a special purpose computer, such as a smartphone.
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Sensor 202 can be any suitable sensor or transducer for detecting ultrasonic energy in a solid medium during failure. For example, in some embodiments, sensor 202 can be a Piezo speaker configured to act as a microphone. More particularly, the sensor can be Piezoelectric diaphragm model number 7BB-27-4L0 from Murata Manufacturing Co., Ltd. of Tokyo, Japan.
As shown in
Amplifier 204 can be any suitable amplifier that can be configured to amplify the signals generated by sensor 202. For example, amplifier 204 can be a variable gain amplifier having any suitable range(s) of gain and any suitable mechanisms for automatically adjusting the gain (Automatic Gain Control). More particularly, for example, amplifier 204 can be configured to have a gain between 40 dB and 60 dB. In some embodiments, for example, amplifier 204 can be implemented using microphone amplifier model number MAX9814ETD+T available from Maxim Integrated of San Jose, Calif.
Analog-to-digital converter 206 can be any suitable analog-to-digital converter for converting the analog signals output by amplifier 204 into digital format usable by the hardware processor.
Hardware processor 208 can be any suitable processor for controlling the functions of sensor module 200 as described herein. For example, in some embodiments, hardware processor 208 can be a microprocessor, a microcontroller, a digital signal processor, and/or any other suitable device for performing the functions described herein. In some embodiments, hardware processor 208 can include any suitable form of memory and/or storage for storing programs and/or data. In some embodiments, although not shown in
As mentioned above, analog-to-digital converter 206 and hardware processor 208 can be implemented, in some embodiments, as one device 214. For example, in some embodiments, device 214 can be implemented using model STM32F051R8T6TR available from STMicroelectronics of Geneva, Switzerland.
Transceiver 210 can be any suitable transceiver for communicating data to and/or from sensor module 200, and may utilize wireless or wire-based communication technologies. For example, in some embodiments, transceiver 210 may be implemented using a model RN2903 Module from Microchip Technology Inc. of Chandler, Ariz.
In some embodiments, analog-to-digital converter 207, hardware processor 208, and transceiver 210 can be implemented as a single device, such as part number CMWX1ZZABZ-078 available from Murata Manufacturing Company, Ltd. of Kyoto, Japan.
In some embodiments, transceiver 210 may be implemented as only a transmitter. In some embodiments, transceiver 210 may be implemented as a separate transmitter and a separate receiver.
Antenna 212 can be any suitable antenna implemented in any suitable manner.
Although not shown in
Also, although not shown in
Generally speaking, in some embodiments, during operation, hardware processor 208 can be configured to control the operation of amplifier 204, analog-to-digital converter 206, and transceiver 210 via one or more control signals. In some embodiments, thus, under the control of the hardware processor, the amplifier can amplify signals from the sensor, the analog-to-digital converter can sample and digitize the amplified signals, the hardware processor can process the digitized signals and provide resulting data to the transceiver, and the transceiver can transmit the data via communication network 104 (
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As illustrated, in process 300, at 302 the process can begin by connecting to communication network 104 (
At 304, process can then wait for a sampling point for sampling the signals detected by sensor 202 (
Next, at 306, the process can determine a combined frequency intensity measurement for the sensor module. This measurement can be determined in any suitable manner. For example, in some embodiments, this measurement can be determined using the process described below in connection with
Then, at 308, the process can determine whether stored combined frequency intensity measurement(s) is(are) to be sent to the server. This determination can be made on any suitable basis. For example, this determination can be made based on the passage of a period of time (e.g., 30 minutes) since the last sending of measurement(s) in some embodiments. As other examples, this determination can be based on available power in a battery or based on available memory in storage of the hardware processor.
If it is determined at 308 to send the measurement(s), then, at 310, process 300 can send the measurement(s) from the sensor module to the server. This can occur in any suitable manner. For example, this can occur by hardware processor 208 (
If it is determined at 308 to not send the data, or after sending the data at 310, process 300 can then loop back to 304.
At 352, process 350 can receive at the server the data sent at 308 from the sensor module.
Then at 354, process 350 can update the data in the user interface, as described below, and loop back to 352.
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Next, at 404, process 400 can perform a Fast Fourier Transform (FFT) on the sampled data. Any suitable parameters for the FFT can be used in some embodiments. For example, in some embodiments, when using a sampling frequency of 253 kHz, an FFT with a size of 256 can be provided with 128 bins (size/2) with a spectral line of 0.988 Khz (253 Khz/256 Khz).
Then, at 406, process 400 can filter out unwanted bands. For Example, in some embodiments, process 400 can ignore data in the FFT output bins for 0-19 kHz and 51-100 kHz.
At 408, the process can average the values of the FFT output bins in the wanted bins. For example, process 400 can average the values of the FFT output bins for 20 kHz to 50 kHz.
Next, at 410, process 400 can zero-out the FFT output bins for all of the wanted bins having values which are lower than twice the average.
Finally, at 412, process 400 can set as the combined frequency intensity measurement value the sum of the values of the wanted bins.
Although specific examples of values (e.g., for frequencies, durations, bin sizes, etc.) are provided in connection with
In some embodiments, to save power, components of the sensor module can be turned off or put into a low power mode when not performing any functions. For example, at 304 (
In some embodiments, server 106 can send parameters, commands, executable code, and/or any other programs or data to sensor module 102. For example, in some embodiments, the server can send parameters specifying the sampling points (which can be specified as specific points in time, as a time interval, and/or in any other suitable manner) (at 304 of
In some embodiments, when monitoring a steam trap, for example, a sensor module can determine the frequency at which the steam trap to which it is connected is cycling between a non-discharge state and a discharge state. The frequency of cycling of the steam trap can be an indicator of the amount of condensate that the steam trap is processing. A frequency of cycling of zero can also indicate that a steam trap has failed in a stuck closed (non-discharge state) or stuck open (discharge state). The energy emitted by the trap and detected by the sensor module can indicate whether the traps is failed in a stuck closed (low energy emitted) or stuck open (high energy emitted) state. This frequency data can then be reported to the server, which can provide the information to a user via the user interface and user device.
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A steam trap can be determined as being faulty in any suitable manner. For example, in some embodiments, a steam trap can be determined as being faulty when a measured combined frequency intensity measurement (or an average thereof) exceeds a given threshold value for more than a given period of time. In some such embodiments, any suitable threshold and any suitable period of time (include 0 seconds) can be used.
As another example, in some embodiments, to determine whether a steam trap is faulty, the following can be performed. First, during a 30-minute period (or any other suitable duration), the monitor can attempt to read 60 (or any other suitable number) consecutive measurements. The period at which these measurements are made, and the number of measurements, can be variable and set as part of the configuration in some embodiments (which can be set via a configuration downlink). Next, after these 60 measurements are collected, the monitor can measure the variance of the readings. This variance can be calculated using the following equation:
where n is an index to the measurements and x is a measurement value. The more the trap cycles the higher the variance is expected to be. A threshold can then be used on the variance to determine whether a trap is operating or whether it is failed. This threshold can variable, can set as part of the configuration, and can be changed during operation via a downlink. If a trap is determined as failed, then an approximation of its failure level is obtained by measuring the acoustic energy in the readings made.
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In some embodiments, a user of the user interfaces in
In some embodiments, any of the data described herein can be provided to and/or received from one or more external systems via any suitable application programming interface (API). Such an API can be used to send or receive any suitable data, to or from any other suitable system, in any suitable format, at any suitable time(s), in any suitable manner. For example, in some embodiments, the data can be sent in JavaScript Object Notation (JSON).
In some implementations, any suitable computer readable media can be used for storing instructions for performing the functions and/or processes described herein. For example, in some implementations, computer readable media can be transitory or non-transitory. For example, non-transitory computer readable media can include media such as non-transitory forms of magnetic media (such as hard disks, floppy disks, etc.), non-transitory forms of optical media (such as compact discs, digital video discs, Blu-ray discs, etc.), non-transitory forms of semiconductor media (such as flash memory, electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), etc.), any suitable media that is not fleeting or devoid of any semblance of permanence during transmission, and/or any suitable tangible media. As another example, transitory computer readable media can include signals on networks, in wires, conductors, optical fibers, circuits, any suitable media that is fleeting and devoid of any semblance of permanence during transmission, and/or any suitable intangible media.
It should be understood that the above described steps of the processes of
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In some embodiments, a silicone (or any other suitable material, e.g., rubber) seal can be provided between the housing body and the housing cover to keep moisture away from the components inside the housing. Likewise, the antenna may be coupled to the circuit board in a manner to provides a moisture tight seal.
In some embodiments, losses can be determined in any suitable manner. For example, in some embodiments, losses can be determined by first calculating the discharge steam loss rate (DSLR) using the following equation:
DSLR=47.12(Orifice Dia){circumflex over ( )}2(PSIG+14.7){circumflex over ( )}0.97,
where:
Next, the energy loss rate (ELR) can be calculated using the following equation:
ELR=(DSLR)*(Leak Factor)(Pressure of saturated steam-Pressure saturated liquid)(Discharge coefficient)(Closed condensate return factor),
where:
Leak Factor=0.55*(acoustic energy measurement/7).
Then, the Therms lost per year (TLPY) can be calculated using the following equation:
TLPY=(Hours of faulty operation)(ELR)/(Boiler Thermal Efficiency %)(BTU to Therm),
where:
Finally, Annual Losses can be calculated using the following equation:
Annual Losses=(TLPY)(User $/Therm),
where User $/Therm is the amount of money that a user pays for Therms.
Although examples are provided above in which all components of a sensor module are implemented adjacent to a steam trap or steam pipe being monitored, in some embodiments, some portions of a module may be located separately from other portions of a module. For example, as illustrated in
In some embodiments, the mechanisms described herein can be used with cyclical steam traps, such as inverted bucket steam traps, thermodynamic steam traps, thermostatic steam traps, and/or any other suitable cyclical steam traps. Such steam traps can be characterized by a behavior in which the steam traps cycle through periods of discharge and no-discharge in some embodiments. During such cycling, the steam traps can emit elevated levels of energy (e.g., ultrasonic energy, audible energy, etc.) when discharging and can emit reduced levels of energy when not discharging, in some embodiments. Cycling can be determined by detecting emitted energy levels from a trap going above an upper threshold and dropping below a lower threshold, which thresholds can be static (e.g., a fixed upper threshold and a fixed lower threshold) or dynamic (e.g., an upper threshold based on the average energy level plus a measured variance minus 20 dB and a lower threshold based on the average energy level minus a measured variance plus 20 dB). These emissions during cycling can approximate a square wave in some embodiments. Such steam traps can cycle with a frequency less than one time per minute to over ten times per minute in some embodiments. To monitor the operation of such a cyclical steam trap in some embodiments, a sensor module can be configured to sample the energy (e.g., ultrasonic energy, audible energy, etc.) output by the steam traps. Each sample can be made in any suitable manner, such as the manner described above. In some embodiments, the sensor module can sample the energy of a trap for 60 ms (or any suitable other duration), every two (or any suitable other number) seconds, over a window of one (or any suitable other number) minute, every 30 (or any suitable other number) minutes. Thus, in the course of one hour, the monitor can perform 30 samples during a first one-minute window and then perform 30 more samples during a second one-minute window approximately 30 minutes later.
By sampling the energy in this manner, an approximate waveform of the steam trap's operation can be formed in some embodiments. From this, a cycle count of the operation of the steam trap, a frequency of operation of the steam trap, a duty cycle of operation of the steam trap, and a condensate loading can be determined in some embodiments.
In some embodiments, any suitable alerts/alarms can be triggered based on this information. For example, in some embodiments, an alert/alarm can be triggered when the difference between the energy sampled during a suspected discharge period and the energy sampled during a suspected non-discharge period is too similar (in other words, square wave amplitude is too small). As another example, in some embodiments, an alert/alarm can be triggered when it is determined that a steam trap has exhibited a rapid increase in cycle counts and followed by a cessation of cycling to warn a user of a possible steam trap overwhelmed with condensate and possible water hammer event. As another example, in some embodiments, an alert/alarm can be triggered when a cyclic steam has stopped cycling and is relatively cold (e.g., relative to steam temperatures).
In some embodiments, monitoring for cycling in a cyclical steam trap can be remotely activated in a sensor module on demand, and any suitable parameters of such monitoring can be remotely programmed.
In some embodiment, to conserve battery power, a sensor module can automatically reduce the number of samples made during periods when normal activity of a steam trap is detected. An example of such a process 1600 in accordance with some embodiments is shown in
For example, each time a sensor module detects normal activity during a monitoring window (e.g., at 1606 and 1608 of
So, as a more particular example, when monitoring a cyclical steam trap, after an initial one-minute monitoring window of normal activity, the count can be set to one (or any other suitable number). This would cause the monitor to skip the next window thirty minutes later and then monitor during the subsequent window sixty minutes later. If normal activity is again detected, this would cause the count to increase and the monitor to skip the next two windows at thirty and sixty minutes later and then monitor during the subsequent window at ninety minutes later. If normal activity is again detected, this would cause the count to increase and the monitor to skip the next three windows at thirty, sixty, and ninety minutes later and then monitor during the subsequent window at 120 minutes later. This process could continue for up to any suitable number of skipped monitoring windows in some embodiments. In some embodiments, the count may be restricted from going above ten (or any other suitable number) skipped windows (e.g., at 1612 of
As another more particular example, when monitoring a non-cyclical steam trap, after an initial 60 ms monitoring window of normal activity, the count can be set to one (or any other suitable number). This would cause the monitor to skip the next window one minute later and then monitor during the subsequent window two minutes later. If normal activity is again detected, this would cause the count to increase and the monitor to skip the next two windows at one and two minutes later and then monitor during the subsequent window at three minutes later. If normal activity is again detected, this would cause the count to increase and the monitor to skip the next three windows at one, two, and three minutes later and then monitor during the subsequent window at four minutes later. This process could continue for up to any suitable number of skipped monitoring windows in some embodiments. In some embodiments, the count may be restricted from going above ten (or any other suitable number) skipped windows. If at any time during monitoring, the sensor detects abnormal activity, the sensor module could reset the count to zero (or any other suitable number).
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In some embodiments, an accelerometer can be included in the sensor module. Any suitable accelerometer, such as part number ISM330DLCTR available from STMicroelectronics of Geneva Switzerland, can be used in some embodiments. The accelerometer can be coupled to a suitable amplifier and threshold detector to detect any suitable vibration event, such as a water hammer event, at steam trap or pipe being measured and cause an alert/alarm to be generated for a user.
It should also be noted that, as used herein, the term mechanism can encompass hardware, software, firmware, or any suitable combination thereof.
Although the invention has been described in the context of monitoring steam traps, it should be apparent that the mechanisms described herein can be used for other purposes without departing from the spirit and scope of the invention. For example, in some embodiments, the mechanisms can be used to detect leaking gas in a gas system (such as a natural gas system, an ammonia gas system, a nitrogen gas system, a hydrogen gas system, and/or any other suitable gas system). As another example, in some embodiments, the mechanisms can be used to determine that a bearing or other mechanical device that is subject to wear failure is failing. As yet another example, in some embodiments, the mechanisms can be used to determine that a valve (such as a water valve or air valve) is failing.
Although the invention has been described and illustrated in the foregoing illustrative implementations, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the invention can be made without departing from the spirit and scope of the invention, which is limited only by the claims that follow. Features of the disclosed implementations can be combined and rearranged in various ways.
This application claims the benefit of U.S. Provisional Patent Application No. 62/808,113, filed Feb. 20, 2019, which is hereby incorporated by reference herein in its entirety. This application is related to U.S. Provisional Patent Application No. 62/712,011, filed Jul. 30, 2018, U.S. patent application Ser. No. 15/884,157, filed Jan. 30, 2018, U.S. Provisional Patent Application No. 62/452,034, filed Jan. 30, 2017, and U.S. Provisional Patent Application No. 62/483,756, filed Apr. 10, 2017, each of which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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62808113 | Feb 2019 | US |