Renewable fuels reduce carbon emissions from vehicles. In an effort to provide a structured market and market-based incentives to track the production of renewable fuels (for example, biodiesel), the United States Environmental Protection Agency (EPA) developed a system of assigning carbon reduction credits to each physical gallon (or gallon equivalent) of renewable fuel produced. The credits originate with the production of the renewable fuel, but once registered through an EPA central registration process, these credits become independently tradeable entities called Renewable Identification Numbers (or RINs). For instance, once produced, one ethanol-equivalent gallon of renewable fuel can be associated with one equivalent Renewable Identification Number (RIN).
A renewable fuel producer must correctly register and initiate the existence of a RIN for each ethanol-equivalent gallon of renewable fuel produced at its production facility. A gallon of renewable fuel can be sold through any number of intermediate market participants before finally being blended with a transport fuel, such as gasoline. In most cases, blending takes place at a refinery or gasoline storage facility. Once used in neat form or in the blending process, each RIN associated with the blended gallon must eventually be retired from the RIN management system, or the RIN credit will expire. In theory, the number of gallons produced should match (or be directly proportional to) the number of RINs in circulation, and the number of ethanol-equivalent gallons of renewable fuel blended should match the number of RINs being retired from the RIN management system on a continual basis.
Unfortunately, however, there have been various instances of fraud associated with such a RIN management system. Thus, it has often been necessary to have third-party auditing or verification of RINs registered and put into market circulation by the producer of a renewable fuel to ensure that there is a true and accurate match with the number of ethanol-equivalent gallons of renewable fuel produced.
The present invention is a method and system for monitoring a production facility for a renewable fuel using operator-independent means to generate operational and production data for the monitored production facility. Such data is then used, for example, to ensure that there is a true and accurate reporting of the number of gallons of renewable fuel produced and the number of registered RINs.
A production facility for a renewable fuel can be broken down and classified into subsections (or areas) based on function. In general, these functions would typically include: (1) intake and storage of feedstock and processing materials; (2) transfer and storage of feedstock and processing material into preprocessing; (3) transfer of feedstock and processing materials into processing tanks; (4) transfer of intermediate products between processing tanks; (5) transfer and storage of end-products and waste by-products of production; and (6) transportation of end-products and waste by-products away from the production facility.
Of course, for a particular production facility, certain operating parameters are known and constant over long periods of time, for example: the number of storage tanks; tank content type; maximum tank volumes; tank heights; number of facility pipelines; pipeline input and output connections; pipeline diameter; number of pumps; pump types; pump function; import loading locations; and export loading locations. Thus, such operating parameters can be identified as part of an initial inspection and profiling of a production facility and stored in a database at a central processing facility.
In order to effectively monitor the production facility, certain operating conditions associated with one or more of the above-described functions must also be monitored. Accordingly, one or more appropriate sensors are chosen for monitoring a selected parameter of a functional subsection, and an appropriate location for each such sensor is then identified. Each sensor may be characterized as a “node” in a network of sensors that monitor the production facility or a functional subsection thereof, and the data from each node is collected at regular intervals and transferred to a central processing facility for storage in a database at the central processing facility.
At the central processing facility, the collected and stored data is then analyzed using a computer program, i.e., computer-readable instructions stored in a memory component and executed by a processor of a computer system. Such analysis of the collected and stored data thus allows for effective monitoring of the functions of the production facility and the development of an automated mass-balance calculator for the production facility.
Data from a sensor may be representative of volume of material present or a flow rate of material entering or leaving with respect to a particular node.
With respect to the measurement of flow rates of materials entering or leaving with respect to a particular node, in some exemplary implementations, to collect flow rate data, current sensors are placed on power cables associated with the pumps in one or more of the functional subsections of the production facility. Each such sensor will monitor and measure the current draw of a particular pump.
With respect to the measurement of flow rates of materials entering or leaving with respect to a particular node, in some exemplary implementations, it might be desirable to install sensors to determine the flow of materials in pipes connecting one or more of the functional subsections of the production facility. For instance, such measurements may be achieved through the installation of flowmeters which provide an output signal representative of the flow rate and cumulative volume of material that has moved through a pipe.
With respect to the measurement of volumes of feedstock, processing materials, and/or product at a production facility or in a particular functional subsection, in some exemplary implementations, sensors are installed to monitor selected tanks and determine the level of material in such tanks, which then allows for a calculation of volume in such tanks.
After collecting and storing data, whether from current sensors, flowmeters, level sensors, or other types of sensors, the data can be analyzed using signal processing techniques and/or charted against the production rates for the production facility and/or against other sources of data provided by the production facility.
Each such data set, alone or in combination with other data sets, can then be compared with historic production data and other operational data from the production facility, including, for example, on times, off times, periods of malfunction or maintenance, and periods at maximum or minimum production rates.
From such comparisons and analysis, a series of transforms are then established which take collected data and transform the collected data into production information, including, for example, production rates, storage volumes, processing rates, product export rates, and feedstock import rates. Similarly, a series of transforms can also be established which take collected data and transform the collected data into operational statuses for the production facility, including, for example, normal operation of the facility, abnormal operation of the facility, facility shut-down, facility start-up, malfunction, and facility at maximum or minimum operating rates.
Once such transforms have been established, they are stored in a database at the central processing facility. As data is subsequently received from one or more sensors, each transform can be applied to the data collected from the one or more sensors. The result of each such application of a transform is a status of the production facility, whether expressed as a production rate or other quantity, or expressed as an operational status (for example, normal or abnormal operations). That result is then communicated to interested parties, including third parties who would otherwise not have access to such status information (because it is ordinarily controlled by operators).
Furthermore, by monitoring operation of a production facility for a renewable fuel in this manner, it is possible to ensure that there is a true and accurate reporting of the number of gallons of renewable fuel produced and the number of registered RINs. Specifically, by monitoring certain operating conditions of the production facility and determining the status of the production facility or identifying any abnormal operations, it can be readily confirmed that the production facility did indeed produce the number of gallons of renewable fuel that have been reported and associated with registered RINs.
The present invention is a method and system for monitoring a production facility for a renewable fuel using operator-independent means to generate operational and production data for the monitored production facility. Such data is then used, for example, to ensure that there is a true and accurate reporting of the number of gallons of renewable fuel produced and the number of registered RINs.
A production facility for a renewable fuel can be broken down and classified into subsections (or areas) based on function. In general, these functions would typically include: (1) intake and storage of feedstock and processing materials; (2) transfer and storage of feedstock and processing material into preprocessing; (3) transfer of feedstock and processing materials into processing tanks; (4) transfer of intermediate products between processing tanks; (5) transfer and storage of end-products and waste by-products of production; and (6) transportation of end-products and waste by-products away from the production facility.
For example, and referring now to
Again, although the above example and
Of course, for a particular production facility, certain operating parameters are known and constant over long periods of time, for example: the number of storage tanks; tank content type; maximum tank volumes; tank heights; number of facility pipelines; pipeline input and output connections; pipeline diameter; number of pumps; pump types; pump function; import loading locations; and export loading locations. Thus, such operating parameters can be identified as part of an initial inspection and profiling of a production facility and stored in a database 10 at a central processing facility 100 (i.e., stored in a memory component of a computer system), as shown in the schematic and flow chart of
In order to effectively monitor the production facility, certain operating conditions associated with one or more of the above-described functions must also be monitored. Accordingly, one or more appropriate sensors is chosen for monitoring a selected parameter of a functional subsection, and an appropriate location for each such sensor is then identified. Each sensor may be characterized as a “node” in a network of sensors that monitor the production facility or a functional subsection thereof, and the data from each node is collected at regular intervals and transferred to a central processing facility for storage in a database 20 at the central processing facility 100 (i.e., stored in a memory component of a computer system), as shown in the schematic and flow chart of
At the central processing facility 100, the collected and stored data is then analyzed using a computer program, i.e., computer-readable instructions stored in a memory component and executed by a processor of a computer system. Thus, execution of the requisite routines and subroutines can be carried out using standard programming techniques and languages. With benefit of the following description, such programming is readily accomplished by one of ordinary skill in the art.
For instance, and as further described below, production at the facility may be modeled from data about: (i) the import of feedstock and processing materials (i.e., “raw materials”) into the production facility or a functional subsection thereof as a function of time; (ii) the raw materials into and out of functional subsections of the production facility as a function of time; and/or (iii) the amount of materials being stored at any time at the production facility or in a functional subsection thereof. Such materials in storage include not only feedstock (e.g., used cooking oil or soybean oil) and processing materials (e.g., methanol and/or catalyst), but also intermediate materials produced during the production cycle (e.g., glycerin), waste materials, and/or finished end-products (e.g., biodiesel). In any event, and as further described below, such analysis of the collected and stored data thus allows for effective monitoring of the functions of the production facility and the development of an automated mass balance calculator for the production facility.
As mentioned above, data from a sensor may be representative of volume of material present or a flow rate of material entering or leaving with respect to a particular node. With respect to the measurement of flow rates of materials entering or leaving with respect to a particular node, in some exemplary implementations, to collect flow rate data, current sensors are placed on power cables associated with the pumps in one or more of the functional subsections of the production facility. In this regard, it is preferred that such placement is non-invasive (e.g., around the power cables) and does not interrupt operation. For example, one preferred sensor for use in the method and system of the present invention is a P3E™ sensor manufactured and distributed by Panoramic Power Ltd. of Kfar Saba, Israel. In other words, sensors are effectively placed “around” a production facility to monitor the production facility, but are not necessarily “in-line” with operations of the production facility. Each such sensor will monitor and measure the current draw of a particular pump. In the case of a biodiesel production facility, pumps of interest may include, but are not limited to: pumps associated with intake of feedstock, methanol, catalyst, and any other needed processing materials in functional subsection 1 (
Referring again to
With respect to the measurement of flow rates of materials entering or leaving with respect to a particular node, in some exemplary implementations, it might be desirable to install sensors to determine the flow of materials in pipes connecting one or more of the functional subsections of the production facility. For instance, such measurements may be achieved through the installation of flowmeters, which use a variety of sensing methods to detect material flow, including, but not limited, to, Coriolis mass flow detection, ultrasonic pulses, and mechanical methods, such as a paddlewheel.
For example, a suitable Coriolis mass flowmeter for use with the present invention is the Optimass 1000 manufactured and distributed by KROHNE Messtechnik GmbH of Duisburg, Germany. Such a Coriolis mass flowmeter is installed in-line in a selected pipe and measures the Coriolis force generated by the fluid traveling through tubes within the flowmeter, which can then be used to calculate flow rate and total volume of material that has moved through the pipe.
For another example, a suitable ultrasonic flowmeter for use with the present invention is the EF10 Wall-Mount Ultrasonic Flowmeter manufactured and distributed by Spire Metering Technology of Acton, Massachusetts. Such an ultrasonic flowmeter can be installed in-line in a selected pipe or placed around a selected pipe. Using a transmitter and receiver, the ultrasonic flowmeter sends ultrasonic pulses through the material being conveyed through the pipe. Based on the transit times of the ultrasonic pulses, a flow rate can be calculated, along with a total volume of material that has moved through the pipe.
For another example, a suitable paddlewheel-type flowmeter for use with the present invention is the Signet 2537 Paddlewheel Flowmeter manufactured and distributed by Georg Fischer Signet LLC of El Monte, Calif. Such a paddlewheel-type flowmeter is installed in-line in a selected pipe and calculates flow rate (and total volume of material that has moved through the pipe) by counting the number of rotations of the paddlewheel.
Regardless of which sensor is used, all such sensors provide an output signal representative of the flow rate and cumulative volume of material that has moved through a pipe. The flow rate and cumulative volume can be viewed as a signal over time for a particular pipe as illustrated in
Referring again to
With respect to the measurement of volumes of feedstock, processing materials, and/or product at a production facility or in a particular functional subsection, in some exemplary implementations, sensors are installed to monitor selected tanks and determine the level of material in such tanks, which then allows for a calculation of volume in such tanks For example, known level sensors include, but are not limited to, differential pressure gauges submerged in a tank, ultrasonic pulse sensors, radar-based sensors, floating devices, and/or switch devices.
For example, a suitable differential pressure gauge for use with the present invention is a combination of the PTX1240 Submersible Pressure Transmitter and Model 9175 wireless tank monitor, both manufactured and distributed by Electronic Sensors, Inc. of Wichita, Kans. In this case, the pressure transmitter is submerged into the material in a selected storage tank and detects the pressure from the volume of material that is above the pressure transmitter. Data from the pressure transmitter is then sent to the tank monitor, which collects the data and calculates the volume.
For another example, a suitable sensor that uses ultrasonic pulses for use with the present invention is an EchoSafe XP88 ultrasonic level transmitter manufactured and distributed by Flowline Inc. of Los Alamitos, Calif. The ultrasonic level transmitter is placed on top of a tank and sends an ultrasonic pulse downward into the tank. The ultrasonic pulse contacts the material stored in the tank and is then reflected back to the transmitter. The tank level (and tank volume) is determined by the amount of time it takes for the pulse to complete its travel.
For another example, a suitable sensor that uses radar signals for use with the present invention is the EchoPulse LR15 pulse radar level transmitter manufactured and distributed by Flowline Inc. of Los Alamitos, Calif. Similar to an ultrasonic level transmitter, the pulse radar level transmitter is placed on top of a tank and sends a radar pulse downward into the tank. The radar pulse contacts the material stored in the tank and is then reflected back to the transmitter. The tank level (and tank volume) is determined by the amount of time it takes for the pulse to complete its travel.
For another example, a suitable sensor that uses mechanical measurements for use with the present invention is the Centeron Float Monitor manufactured and distributed by Robertshaw Industrial Products of Maryville, Tenn. Such a float monitor makes use of a physical probe that is either submerged in or floats on top of the material stored in the tank. Using data collected from the probe, the tank level (and tank volume) is calculated.
For another example, a suitable sensor that uses temperature measurement for use with the present invention is the StorMax Retractable Temperature Cable manufactured and distributed by OPlsystems Inc. of Calgary, Alberta, Canada. A probe at a distal end of the cable is submerged into the material in a selected storage tank. The probe includes multiple thermocouples along its length. Based on the temperature differential at each thermocouple, the tank level (and tank volume) is calculated.
For another example, infrared sensing techniques, such as those described in U.S. Pat. No. 8,717,434, which is entitled “Method and System for Collecting and Analyzing Operational Information from a Network of Components Associated with a Liquid Energy Commodity” and is incorporated herein by reference, may be employed to determine levels within tanks of interest.
All such sensors provide a level of a storage tank at a production facility and, in turn, provide the current volume of the storage tank. The level reported by a tank level meter over time can be represented as a signal for a particular tank as illustrated in
Referring again to
After collecting and storing data, whether from current sensors, flowmeters, level sensors, or other types of sensors, the data can be analyzed using signal processing techniques and/or charted against the production rates for the production facility and/or against other sources of data provided by the production facility. Examples of sensor-derived data sets include:
1. sensor signal amplitudes defined by minimum, maximum, and average;
2. sensor signal frequency defined by repetitive signal occurrence (cycles per time period) and periodicity (time delays between repeating signal patterns);
3. rate of change in signal on/off rates and transitions from one signal amplitude to another (i.e., pattern sets);
4. relative signal-to-noise ratios; and
5. relative timing of signals from different pumps (or nodes) derived from signal cross-correlation analysis.
Each such data set, alone or in combination with other data sets, can then be compared with historic production data and other operational data from the production facility, including, for example, on times, off times, periods of malfunction or maintenance, and periods at maximum or minimum production rates. With respect to operational data from the production facility, one contemplated way to collect such data is the use of a PLC-interface device which directly connects to the internal operational SCADA system at the production facility, for example, by setting up a data feed that routes the data from the SCADA system offsite for subsequent review and analysis.
For example, commonly owned U.S. Pat. No. 8,972,273 is entitled “Method and System for Providing Information to Market Participants about One or More Power Generating Units Based on Thermal Image Data.” U.S. Pat. No. 8,972,273, which is incorporated herein by reference, describes a method and system that allows for an accurate assessment of the operational status of a particular power plant (or similar facility), including an identification of which power generating units are on and which are off. An exemplary system in includes, inter alia: (i) a monitor component for acquiring thermal data from a smokestack and/or the gas plume emitted from the smokestack of a power plant (or similar facility); (ii) a video capture component for recording images of the acquired thermal data; (iii) a data transmission component for transmitting the recorded images to a central processing facility; and (iv) an analysis component for analyzing the recorded images and, using one or more databases storing information regarding the nature and capability of that power plant (or similar facility), drawing an inference as to the operational status of that power plant (or similar facility). The resultant data may be accessed and used in the method and system of the present invention.
For another example, commonly owned U.S. Pat. No. 8,842,874 is entitled “Method and System for Determining an Amount of a Liquid Energy Commodity Stored in a Particular Location.” U.S. Pat. No. 8,842,874 , which is incorporated herein by reference, notes that many liquid energy commodities are stored in large, above-ground tanks that either have: a floating roof, which is known as an External Floating Roof (EFR); or a fixed roof with a floating roof internal to the tank, which is known as an Internal Floating Roof (IFR). U.S. Pat. No. 8,842,874 thus describes and claims a method for determining an amount of a liquid energy commodity stored in a particular location, including, inter alia: (i) storing volume capacity information associated with each tank at the particular location in a database; (ii) periodically conducting an inspection of each tank at the particular location from a remote vantage point and without direct access to each tank, including collecting one or more images of each tank; (iii) transmitting the collected images of each tank to a central processing facility; (iv) analyzing the collected images of each tank to determine a liquid level for each tank; and (v) calculating the amount of the liquid energy commodity in each tank based on the determined liquid level and the volume capacity information retrieved from the database. The resultant data may also be accessed and used in the method and system of the present invention.
For another example, commonly owned U.S. Pat. No. 8,717,434 is entitled “Method and System for Collecting and Analyzing Operational Information from a Network of Components Associated with a Liquid Energy Commodity.” U.S. Pat. No. 8,717,434, which is incorporated herein by reference, thus describes and claims a method that includes, inter alia: (i) measuring an amount of a liquid energy commodity in storage at one or more storage facilities in the network, and storing that measurement data in a first database at a central data processing facility; (ii) determining a flow rate of the liquid energy commodity in one or more selected pipelines in the network, and storing that flow rate data in a second database at the central data processing facility; (ii) ascertaining an operational status of one or more processing facilities in the network, and storing that operational status information in a third database at the central data processing facility; and (iv) analyzing the measurement data, the flow rate data, and the operational status information to determine a balance of the liquid energy commodity in the network or a selected portion thereof at a given time. The resultant data may also be accessed and used in the method and system of the present invention.
Referring again to
Similarly, as also indicated by block 200, a series of transforms are also established which take collected data and transform the collected data into operational statuses for the production facility, including, for example, normal operation of the facility, abnormal operation of the facility, facility shut-down, facility start-up, malfunction, and facility at maximum or minimum operating rates.
Once such transforms have been established, they are stored in a database 30 at the central processing facility 100 (i.e., stored in a memory component of a computer system), as indicated by block 202 in the schematic and flow chart of
For a sensor placed on a power cable associated with a particular pump to monitor and measure the current draw of the pump, the sensor outputs a current output signal, Ipi.
By accessing and using other available information from the production facility (whether from public databases, prior collected data, information acquired from the production facility, or otherwise), such as production data, flow meter data, or tank level data, a transform is then established to correlate the flow rate of material through the pump, Qpi, to the current output signal, Ipi.
Then, flow can be modeled with a linear regression:
Q
pi
=m*I
pi
+b (1)
where m is the slope, and b is the y-intercept of the linear regression. Variables m and b will vary based on factors, including the type of pump(s), power of the pump(s), and the fluid properties of the material being transferred through the pump(s).
Once one or more pumps related to a production facility have been identified, sensors have been placed to collect data from such pumps, and a transform (or model) has been established for each pump, the overall flow of materials through the production facility can be monitored. Specifically, when the flow rate of material, Qi, through each pump at a given time has been calculated, the volume of material flowing into and out of each functional subsection, Vi, can be estimated:
ΔV
i
=Q
i
*Δt (2)
where Δt is the change in time.
During normal operations of a production facility, the operational profile regarding mass balances associated with each stage in the production of the renewable fuel will follow a defined pattern.
V
in
=V
in1
+V
in2
+V
in3
+ . . . +ΣV
ini (3)
V
process
=V
process1
+V
process2
+V
process3
+ . . . +ΣV
processi (4)
V
out
=V
out1
+V
out2
+V
out3
+ . . . +ΣV
outi (5)
Vin=Vprocess=Vout (6)
where Vin is the total volume derived from the flow rates of all incoming pumps, Vprocess is the total volume derived from the flow rates of all pumps moving product into process, and Vout is the total volume derived from the flow rates of all outgoing pumps.
Abnormal operations at a production facility can then be defined as any time that equation (6) is not true.
In addition, and as illustrated in
For a tank levelmeter installed on a tank, the meter outputs a net volume change, ΔVi, which is calculated by subtracting the total amount of material injected into a tank, ΣVii, from the total amount of material withdrawn from a tank, ΣVwi, or:
ΔV
i
=ΣV
ii
−ΣV
wi (7)
As discussed above,
Q
i
=ΔV
i
/Δt (8)
where Qi is the flow rate through the tank, and Δt is the change in time.
By accessing and using other available information from the production facility (whether from public databases, prior collected data, information acquired from the production facility, or otherwise), such as production data, flow meter data, or additional tank level data, a transform is then established to verify the net volume change, ΔVi, and corresponding flow rate of material through in the tank, Qi. If the measured net volume change and flow rate of material through the tank is not within an acceptable error of the net volume change and flow rate determined through the collection of production facility data, the net volume change and flow rate can then be defined as
V
i
=V
im
+V
ierr (9)
Q
i
=Q
im
+Q
ierr (10)
where Vim is the measured volume change in the tank, Qim is the measured flow rate through the tank, Vierr is i a value to offset the error between the measured flow rate and production facility data, and Qierr is a value to offset the error between the flow rate measurement and production facility data.
Once one or more tanks of a production facility have been identified and sensors have been placed to collect data from such tanks, the overall flow of materials through the production facility can be monitored. Specifically, when the flow rate of material, Qi, through each tank at a given time has been calculated, the volume of material flowing into and out of each functional subsection, Vi, can be estimated using equation (9).
During normal operations of a production facility, the operational profile regarding mass balances associated with each stage in the production of the renewable fuel will follow a defined pattern. Again,
V
in
=V
in1
+V
in2
+V
in3
+ . . . +ΣV
ini (11)
V
process
=V
process1
+V
process2
+V
process3
+ . . . +ΣV
processi (12)
V
out
=V
out1
+V
out2
V
out3
+ . . . +ΣV
outi (13)
Vin=Vprocess=Vout (14)
where Vin is the sum of volumes injected into all incoming tanks, Vprocess is the sum of the volumes injected into all tanks moving product into process, and Vout is sum of the volume withdrawn from all outgoing tanks
Abnormal operations at a production facility can then be defined as any time that equation (14) is not true.
In addition, and as also illustrated in
For a flowmeter installed on a pipe associated with the movement of material from one functional subsection to another in a biodiesel production facility, the flowmeter outputs a flow signal, Qi, and cumulative volume signal, Vi.
By accessing and using other available information from the production facility (whether from public databases, prior collected data, information acquired from the production facility, or otherwise), such as production data, additional flow meter data, or tank level data, a transform is then established to verify the net volume change, ΔVi, and corresponding flow rate of material through in the pipe, Qi. If the measured net volume change and flow rate of material through the pipe is not within an acceptable error of the net volume change and flow rate determined through the collection of production facility data, the net volume change and flow rate can then be defined as
V
i
=V
im
+V
ierr (15)
Q
i
=Q
im
+Q
ierr (16)
where Vim is the measured volume change in the pipe, Qim is the measured flow rate through the pipe, Vierr is a value to offset the error between the measured flow rate and production facility data, and Qierr is a value to offset the error between the flow rate measurement and production facility data.
Once one or more pipes related to a production facility have been identified, and flowmeters have been placed to collect data from such pipes, the overall flow of materials through the production facility or a functional subsection of the production facility can be monitored. Specifically, when the flow rate of material, Qi, through each pipe at a given time has been calculated, the volume of material flowing into and out of each functional subsection, Vi, can be estimated using equation (2) above.
During normal operations of a production facility, the operational profile regarding mass balances associated with each stage in the production of the renewable fuel will follow a defined pattern. Again,
V
in
=V
in1
+V
in2
+V
in3
+ . . . +ΣV
ini (17)
V
process
=V
process1
+V
process2
+V
process3
+ . . . +ΣV
processi (18)
V
out
=V
out1
+V
out2
+V
out3
+ . . . +ΣV
outi (19)
Vin=Vprocess=Vout (20)
where Vin is the sum of volumes through incoming pipes, Vprocess is the sum of the volumes through all pipes moving product into process, and Vout is the sum of the volumes through all outgoing pipes.
Abnormal operations at a production facility can then be defined as any time that equation (20) is not true.
In addition, and as also illustrated in
T
tot
=T
A
+T
off
+T
B (21)
By measuring the length of time between the last trailing edge of one pumping period and the start leading edge of the next pumping period, an expected pumping sequence can be identified. Such a pumping sequence identifies normal operations at a production facility, and any deviations would be considered abnormal operations.
In order to determine the pumping sequence relationship on a real-time basis, a cross-correlation function is applied to the current output signals. The function used to determine the relationship between the two signals is:
where A and B represent the pump current signals, and N is the total number of signal data points used in the cross-correlation function for A and B.
A Matlab® script can be used to analyze this data on a real-time basis using the xcorr function. (Matlab® is a registered trademark of The Mathworks Inc. of Natick, Mass.)
The xcorr function returns a vector, c, of length 2N-1 containing the cross correlation sequence.
c=xcorr(A,B) (23)
Using c, the time lag, Tiag, between pumping sequences can be determined by subtracting the position of the highest correlated point (zero lag) from N.
Now, in order to ascertain how well the two signals correspond to one another at the highest correlated point, the correlation coefficient vector, r, is found using the same Matlab® xcorr function as above with an additional option.
r=xcorr(A,B,‘coeff’) (24)
It can thus be determined that Pump A begins operations at an expected lag, Tlag, of 23 minutes before Pump B begins to operate. This is confirmed by a coefficient of correlation, R, of 0.94. Thus, every time Pump A begins operations, it is expected that Pump B will begin operations 23 minutes later. If it does not happen, or if it is determined that Pump B begins operations before Pump A, an abnormal operational pattern is identified. Data on normal or abnormal operation can then be communicated to interested parties.
tot
=T
A
+T
off
+T
B (25)
By measuring the length of time between the last trailing edge of one injection period and the start leading edge of the next injection period, an expected transfer sequence can be identified. Such a transfer sequence identifies normal operations at a production facility, and any deviations would be considered abnormal operations.
In order to determine the transfer sequence relationship on a real-time basis, a cross-correlation function is applied to the volume change signals. The function used to determine the relationship between the two signals is:
where A and B represent the volume change signals, and N is the total number of signal data points used in the cross-correlation function for A and B.
Again, a Matlab® script can be used to analyze this data on a real-time basis using the xcorr function. The xcorr function returns a vector, c, of length 2N-1 containing the cross correlation sequence.
c=xcorr(A,B) (27)
Using c, the time lag, Tlag, between transfer sequences can be determined by subtracting the position of the highest correlated point (zero lag) from N. Again,
Now, in order to ascertain how well the two signals correspond to one another at the highest correlated point, the correlation coefficient vector, r, is found using the same Matlab® xcorr function as above with an additional option.
r=xcorr(A,B,‘coeff’) (28)
It can thus be determined that Tank A begins injection at an expected lag, Tlag, of 23 minutes before Tank B begins to inject material. This is confirmed by a coefficient of correlation, R, of 0.94. Thus, every time Tank A begins injection, it is expected that Tank B will begin injection 23 minutes later. If it does not happen, or if it is determined that Tank B begins injection before Tank A, an abnormal operational pattern is identified. Again, data on normal or abnormal operation can then be communicated to interested parties.
T
tot
=T
A
+T
off
+T
B (29)
By measuring the length of time between the last trailing edge of one pipe flow period and the start leading edge of the next pipe flow period, an expected transfer sequence can be identified. Such a transfer sequence identifies normal operations at a production facility, and any deviations would be considered abnormal operations.
In order to determine the transfer sequence relationship on a real-time basis, a cross-correlation function is applied to the flow rate signals. The function used to determine the relationship between the two signals is:
where A and B represent the flow rate signals, and N is the total number of signal data points used in the cross-correlation function for A and B.
Again, a Matlab® script can be used to analyze this data on a real-time basis using the xcorr function. The xcorr function returns a vector, c, of length 2N-1 containing the cross correlation sequence.
c=xcorr(A,B) (31)
Using c, the time lag, Tlag, between transfer sequences can be determined by subtracting the position of the highest correlated point (zero lag) from N. Again,
Now, in order to ascertain how well the two signals correspond to one another at the highest correlated point, the correlation coefficient vector, r, is found using the same Matlab® xcorr function as above with an additional option.
r=xcorr(A,B,‘coeff’) (32)
It can thus be determined that material begins flow through Pipe A at an expected lag, Tlag, of 23 minutes before material begins to flow through Pipe B. This is confirmed by a coefficient of correlation, R, of 0.94. Thus, every time material begins flow through Pipe A, it is expected that material flow through Pipe B will begin 23 minutes later. If it does not happen, or if it is determined that material flows through Pipe B before Pipe A, an abnormal operational pattern is identified. Again, data on normal or abnormal operation can then be communicated to interested parties.
It can also be determined what a particular pump is being used for at a production facility based on certain signal characteristics, including period of pump usage, amplitudes, leading edge patterns, number of peaks, and ramp/decay rates.
As shown in
r
0
=xcorr(Si,Xi,0,‘coeff’) (33)
where Si is the signal associated with a known pumping type, and Xi is the signal associated with an unknown pumping type. r0 will be a value between 0 and 1; the more correlation between the signals, the closer r0 will be to 1. Based on r0's value set against expected r0 results set for a particular pump, it can be determined if the unknown signal matches any known signals (S1, S2, S3, etc.) or if it is a new type of signal.
Similar analysis can be used to determine expected operational patterns at different time granularities as well. During normal operational periods, pump usage is expected to be similar from day-to-day, as reflected in
It can also be determined what a particular tank is being used for at a production facility based on certain signal characteristics, including period of tank injections/withdrawals, amplitudes (i.e., volumes injected or withdrawn from a tank), leading edge patterns, number of peaks, and ramp/decay rates.
As shown in
r
0
=xcorr(Si,Xi,0,‘coeff’) (34)
where Si is the signal associated with a known tank level change, and Xi is the signal associated with an unknown tank level change. r0 will be a value between 0 and 1; the more correlation between the signals, the closer r0 will be to 1. Based on r0's value set against expected r0 results set for a particular tank level change, it can be determined if the unknown signal matches any known signals (S1, S2, S3, etc.) or if it is a new type of signal.
Similar analysis can be used to determine expected operational patterns at different time granularities as well. During normal operational periods, tank level changes are expected to be similar from day-to-day, as reflected in
It can also be determined what a particular pipe is being used for at a production facility based on certain flow signal characteristics, including period of usage, amplitudes (i.e., flow rates), leading edge patterns, number of peaks, and ramp/decay rates.
As shown in
r
0
=xcorr(Si,Xi,0,‘coeff’) (35)
where Si is the signal associated with a known flow type, and Xi is the signal associated with an unknown flow type. r0 will be a value between 0 and 1; the more correlation between the signals, the closer r0 will be to 1. Based on r0's value set against expected r0 results set for flow through a particular pipe, it can be determined if the unknown signal matches any known signals (S1, S2, S3, etc.) or if it is a new type of signal.
Similar analysis can be used to determine expected operational patterns at different time granularities as well. During normal operational periods, total flow through all pipes at a production facility is expected to be similar from day-to-day, as reflected in
Again, and as described above in the Example Transforms, once established, as data is received from one or more sensors, as indicated by block 300 of
Furthermore, by monitoring operation of a production facility for a renewable fuel in this manner, it is possible to ensure that there is a true and accurate reporting of the number of gallons of renewable fuel produced and the number of registered RINs. Specifically, by monitoring certain operating conditions of the production facility and determining the status of the production facility or identifying any abnormal operations, it can be readily confirmed that the production facility did indeed produce the number of gallons of renewable fuel that have been reported and associated with registered RINs. In other words, a determination can be made as to whether the production rate (as determined through application of the transforms) over an defined time period is consistent with the registration of RINs for the same defined time period.
One of ordinary skill in the art will recognize that additional embodiments and implementations are also possible without departing from the teachings of the present invention. This detailed description, and particularly the specific details of the exemplary embodiments and implementations disclosed therein, is given primarily for clarity of understanding, and no unnecessary limitations are to be understood therefrom, for modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without departing from the spirit or scope of the invention.
The present application claims priority to U.S. patent application Ser. No. 62/024,852 filed on Jul. 15, 2014.
Number | Date | Country | |
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62024852 | Jul 2014 | US |