JP2019070662A - Apparatus for determining differential zero offset in vibrating flowmeter and related method - Google Patents

Abstract

To provide a method for operating a system configured to consume a fluid, such as an engine fluid, having at least two flowmeters.SOLUTION: The method includes the step of recirculating a fluid in a closed loop having a supply-side flowmeter and a return-side flowmeter, such that substantially no fluid is consumed. A fluid flow is measured in the supply-side flowmeter and the return-side flowmeter 702. Fluid flow measurements are compared between the supply-side flowmeter and the return-side flowmeter, and a first differential zero value is determined based on the difference in the fluid flow measurements between the supply-side flowmeter and the return-side flowmeter. A first temperature sensor signal value is received and is associated with the first differential zero value. The first differential zero value associated with the first temperature sensor signal value is stored in a meter electronic apparatus.SELECTED DRAWING: Figure 7

Description

  The present invention relates to flow meters, and more particularly to methods and apparatus for determining the change in zero offset of a vibratory flow meter.

Vibratory sensors, such as vibratory densitometers and Coriolis flowmeters, are generally well known and are used to measure the mass flow rate and other information of material flowing through a conduit in the flowmeter. Exemplary Coriolis flowmeters are disclosed in US Pat. No. 4,109,524, US Pat. No. 4,491,025, and Reissued Pat. No. 31,450, all by JES Mith et al.
These flow meters have one or more conduits in a linear or curved configuration. For example, each conduit configuration in a Coriolis mass flowmeter has a set of natural vibration modes that can be simple bending, twisting, or a combined type. Each conduit can be driven to vibrate in the preferred mode.

  Material enters the flow meter from piping connected to the inlet side of the flow meter, is directed through the conduit (s), and exits the flow meter through the outlet side of the flow meter. The natural vibration mode of the vibratory system is partly defined by the conduit and the combined mass of the material flowing in the conduit.

  When there is no flow in the flow meter, the driving force applied to the conduit (s) is the same phase at all points along the conduit (s) or the time delay measured when the flow is zero Vibrate at some small "zero offset". As the material begins to flow through the flow meter, the Coriolis force causes each point along the conduit (s) to have a different phase. For example, the phase at the inlet end of the flow meter lags the phase at the central driver position and the phase at the outlet leads the phase at the central driver position. Pickoff on the conduit (s) produces a sinusoidal signal that represents the operation of the conduit (s). The signal output from the pickoff is processed to determine the time delay between pickoffs. The time delay between two or more pickoffs is proportional to the mass flow rate of material flowing through the conduit (s).

  Meter electronics coupled to the driver generate a drive signal to activate the driver to determine the mass flow rate of the material and other characteristics from the signal received from the pickoff. The driver can be equipped with one of many well known configurations, but magnets and opposing drive coils have had great success in the flow meter industry. An alternating current is passed through the drive coil to oscillate the conduit (s) at the desired flow tube amplitude and frequency. It is also known in the art to provide pickoffs such as magnet and coil arrangements that are very similar to driver arrangements. However, the driver receives a current that induces operation, and the pickoff can induce a voltage using the operation provided by the driver. The magnitude of the time delay measured by pickoff is very small, often measured in nanoseconds. Therefore, it is necessary that the converter output be very accurate.

In general, a Coriolis flowmeter may be initially calibrated to generate a flow calibration factor with zero offset. In use, the flow calibration factor can be generated by multiplying the time delay measured by pickoff minus the zero offset to produce a mass flow rate. In most situations, the flow meter is initially calibrated, usually by the manufacturer, and is assumed to provide accurate measurements without the need for subsequent calibration. In addition, the prior art approach involves the user zeroing the flow meter by stopping the flow after installation and closing the valve, thus giving the meter a zero flow reference at process conditions.

  As mentioned above, in many vibration sensors, including Coriolis flowmeters, zero offsets may exist, and the prior art approach corrects this initially. Although this initially determined zero offset can correct the measurement properly in limited circumstances, it should change over time due to changes in various operating conditions, mainly temperature changes. As a result, the correction is partial. However, other operating conditions, including pressure, fluid density, sensor mounting conditions, etc. may also affect zero offset. Additionally, the zero offset may change at different rates from meter to meter. This may be of particular interest in situations where two or more meters are connected in series such that each of the meters reads the same if the same fluid flow is being measured.

In the shipping industry applications, sailing vessels often use a fuel switching scheme whereby marine engines operate with different types of fuel (or mixtures thereof). Heavy fuel oil (HFO) and marine diesel (MDO) or marine fuel (MFO) are usually used fuels. When the fuel source is switched, the HFO operating temperature between about 120 and 150 ° C. is changed to an operating temperature of about 30 to 50 ° C. for MDO / MFO. There is a temperature difference of about 50 ° C. between the two operating temperatures, which causes a temperature induced zero drift problem.
Accordingly, there is a need in the art for a method for determining and compensating for changes in the zero offset of a vibratory sensor where the operating temperature changes. The present invention overcomes this and other problems and advances in the art are achieved.

A method for operating a system configured to consume fluid having at least two flow meters is provided by one embodiment. In the present embodiment,
Recirculating the fluid in a closed loop having a feed flow meter and a return flow meter, such that the fluid is not substantially consumed;
Measuring the flow of fluid in the supply flow meter and the return flow meter;
Comparing fluid flow measurements between a supply flow meter and a return flow meter;
Determining a first difference zero value based on differences in fluid flow measurements between the supply flow meter and the return flow meter;
Receiving a first temperature sensor signal value;
Relating a first difference zero value to a first temperature sensor signal value;
Storing, in the meter electronics, a first differential zero value associated with the first temperature sensor signal value.

A method for operating a multiple fuel system having an engine, at least two fuel tanks each configured to contain different fuels, and at least a supply flow meter and a return flow meter, according to one embodiment Provided. In the present embodiment,
Recirculating the first fuel type in a closed loop while the engine is not operating so that fuel is not substantially consumed;
Measuring the flow of the first fuel in the supply flow meter and the return flow meter;
A first fuel flow measurement is compared between the supply flow meter and the return flow meter, and a first differential zero value based on the difference in the fuel flow measurement between the supply flow meter and the return flow meter. Determining the
Receiving a first temperature sensor signal value;
Associating a first difference zero value with a first temperature sensor signal value and a first fuel type;
Storing in the meter electronics a first temperature sensor signal value and a first differential zero value associated with the first fuel type;
Recirculating the second fuel type in a closed loop while the engine is not operating so that fuel is not substantially consumed;
Measuring the flow of a second fuel in the supply flow meter and the return flow meter;
A second fuel flow measurement is compared between the supply flow meter and the return flow meter, and a second differential zero value based on the difference in the fuel flow measurement between the supply flow meter and the return flow meter. Determining the
Receiving a second temperature sensor signal value;
Relating a second difference zero value to a second temperature sensor signal value and a second fuel type;
Storing in the meter electronics a second temperature sensor signal value and a second differential zero value associated with the second fuel type.

Meter electronics for a flow meter, including a processing system, coupled to a system having an engine are provided by one embodiment. According to this embodiment, the meter electronic device
While the engine is not running, receive sensor signals from both the supply and return flow meters,
Determine a differential zero offset between the supply flow meter and the return flow meter based on the received sensor signal;
Determine the temperature of at least one of the supply flow meter or the return flow meter,
Associate a differential zero offset to temperature,
A differential zero offset associated with the temperature is configured to sum up in the meter electronics.

According to an aspect one aspect, a method for operating the at least two flow meters, arranged to consume fluid system is provided. This aspect comprises the steps of recirculating fluid in a closed loop having a feed flow meter and a return flow meter such that the fluid is not substantially consumed, and fluid in the feed flow meter and the return flow meter Measuring the flow, comparing the fluid flow measurement between the supply flow meter and the return flow meter, and based on the difference in the flow measurement between the supply flow meter and the return flow meter Determining a first difference zero value, receiving a first temperature sensor signal value, associating the first difference zero value with the first temperature sensor signal value, and detecting the first temperature sensor signal value Storing in the meter electronics a first difference zero value associated with.

Preferably, a plurality of differential zero values are determined and stored for each of the first temperature sensor signal values at different time points and associated with the first temperature sensor signal value.
Preferably, this aspect averages a plurality of difference zero values to calculate an averaged plurality of difference zero values, and associates the averaged plurality of difference zero values with the first temperature sensor signal value. Storing the averaged plurality of difference zero values associated with the first temperature sensor signal value in the meter electronics.
Preferably, the present aspect includes applying statistical analysis to the plurality of difference zero values and discarding the out-of-difference zero values.

Preferably, this aspect comprises the steps of: operating the engine disposed between the supply flow meter and the return flow meter such that fluid is consumed; and while the engine is operating, the supply flow meter Receiving temperature sensor signal values from at least one of the return flowmeters, measuring fluid flow in the supply flowmeters and return flowmeters while the engine is operating, and consuming engine fluid Calculating engine fluid consumption by comparing fluid flow measurements between the supply flow meter and the return flow meter using the quantity equation, and the difference associated with the temperature sensor signal in the meter electronics Applying the zero value to the engine fluid consumption equation; and outputting the adjusted fluid consumption measurement corrected for the operating temperature.

Preferably, this aspect comprises measuring the flow of the second fluid in the supply flow meter and the return flow meter, and measuring the second fluid flow between the supply flow meter and the return flow meter. Comparing and determining a second difference zero value based on differences in fluid flow measurements between the supply flow meter and the return flow meter, and from at least one of the supply flow meter and the return flow meter Receiving a second temperature sensor signal value, associating a second differential zero value with the second temperature sensor signal, and metering the second differential zero value associated with the second temperature sensor signal value Storing in the device.

Preferably, this aspect comprises the steps of: operating the engine disposed between the supply flow meter and the return flow meter such that fluid is consumed; and while the engine is operating, the supply flow meter Receiving temperature sensor signal values from at least one of the return flowmeters, measuring fluid flow in the supply flowmeters and return flowmeters while the engine is operating, and consuming engine fluid Calculating engine fluid consumption by comparing fluid flow measurements between a supply flow meter and a return flow meter using a quantity equation, the supply flow meter while the engine is operating, and If the temperature sensor signal value received from at least one of the return flow meters is within a threshold associated with the first temperature sensor signal value in the meter electronics, then the first in the meter electronics is Applying to the engine fluid consumption equation a differential zero value associated with the power sensor signal value, and a temperature sensor received from at least one of the supply flow meter and the return flow meter while the engine is operating If the signal value is within the threshold associated with the second temperature sensor signal value in the meter electronics, then the differential zero value associated with the second temperature sensor signal value in the meter electronics is the engine fluid consumption Applying to the equation; and outputting the adjusted fluid consumption measurement corrected for the operating temperature.

Preferably, in the aspect, the temperature sensor signal value received from at least one of the supply flow meter and the return flow meter while the engine is operating is a first temperature sensor signal value in the meter electronics and Interpolated differential zero values derived from the first temperature sensor signal value and the second temperature sensor signal value in the meter electronics, when between the second temperature sensor signal values in the meter electronics, and the engine fluid consumption Including applying to a quantity equation.

Preferably, in the aspect, the temperature sensor signal value received from at least one of the supply flow meter and the return flow meter while the engine is operating is a first temperature sensor signal value in the meter electronics and If it is outside the range of the second temperature sensor signal value in the meter electronics, the extrapolated difference zero value derived from the first temperature sensor signal value and the second temperature sensor signal value in the meter electronics may be Apply to the fluid consumption equation.

According to one aspect, a method for operating a multiple fuel system having an engine, at least two fuel tanks each configured to contain different fuels, and at least a supply flow meter and a return flow meter. Is provided. The method comprises the steps of: recirculating a first fuel type in a closed loop such that fuel is not substantially consumed while the engine is not operating; and first in a supply flow meter and a return flow meter. Measuring the flow of fuel and comparing the first fuel flow measurement between the supply flow meter and the return flow meter, and the difference in the fuel flow measurement between the supply flow meter and the return flow meter Determining a first difference zero value based on the step of receiving a first temperature sensor signal value and associating the first difference zero value with the first temperature sensor signal value and the first fuel type Storing in the meter electronics a first temperature sensor signal value and a first difference zero value associated with the first fuel type.
Recirculating the second fuel type in a closed loop such that the fuel is not substantially consumed while the engine is not operating; and a flow of the second fuel in the supply flow meter and the return flow meter Measuring the second fuel flow measurement value between the supply flow meter and the return flow meter, and based on the difference in the fuel flow measurement between the supply flow meter and the return flow meter No. 2
Determining a differential zero value of the second value, receiving a second temperature sensor signal value, associating the second differential zero value with a second temperature sensor signal value and a second fuel type, and Storing the temperature sensor signal value and a second differential zero value associated with the second fuel type in the meter electronics.

Preferably, this aspect comprises the steps of operating the engine using a first fuel type, measuring at least one first operating temperature of the supply flow meter and the return flow meter, and Extracting a first differential zero value corresponding to the operating temperature and the first fuel type; applying a first differential zero value to the engine fluid consumption equation; a first operating temperature and a first fuel Outputting the adjusted fluid consumption measurement value calculated using the engine fluid consumption equation corrected for the type.

Preferably, this aspect comprises the steps of: switching fuel types for engine operation; measuring at least one second operating temperature of the supply flow meter and the return flow meter;
Retrieving a second difference zero value corresponding to a second operating temperature and a second fuel type;
Applying a second difference zero value to the engine fluid consumption equation and adjusted using the engine fluid consumption equation corrected for the second operating temperature and the second fuel type Outputting the fluid consumption measurement.

  According to one aspect, meter electronics for a flow meter including a processing system coupled to a system having an engine are provided. The meter electronics receives sensor signals from both the supply flow meter and the return flow meter while the engine is not operating, and between the supply flow meter and the return flow meter based on the received sensor signals. Determine the differential zero offset, determine the temperature of at least one of the supply flow meter or the return flow meter, associate the differential zero offset with the temperature, and store the differential zero offset associated with the temperature in the meter electronics Configured

Preferably, the processing system determines a first operating temperature of at least one of the supply flow meter or the return flow meter, and the first operating temperature is stored in the meter electronics at one or more previous times. Apply the zero offset associated with the first operating temperature to the calculation for determining the engine fuel consumption if the previously determined zero offset is associated with the first operating temperature as compared to the temperature of Configured

Preferably, the processing system determines at least one second operating temperature of the supply flow meter or the return flow meter, and the second operating temperature is stored in the meter electronics at one or more previous times. To apply the zero offset associated with the second operating temperature to the calculation for determining the engine fuel consumption if the previously determined zero offset is associated with the second operating temperature as compared to the temperature of Configured

  Preferably, the processing system stores a plurality of differential zero offsets associated with respective temperatures of at least one of the supply flow meter or the return flow meter, and the measured operating temperature comprises a plurality of respective temperatures. The method is configured to calculate an interpolated zero offset and to apply the interpolated zero offset associated with the measured operating temperature to the calculation for determining the engine fuel consumption, if it is between at least two of.

Preferably, the processing system stores a plurality of differential zero offsets associated with respective temperatures of at least one of the supply flow meter or the return flow meter, and the measured operating temperature comprises a plurality of respective temperatures. Is configured to calculate an extrapolated zero offset, and apply the extrapolated zero offset associated with the measured operating temperature to the calculation for determining engine fuel consumption.
Preferably, the processing system is configured to switch between a plurality of stored zero offset values associated with each stored temperature to correspond to the operating temperature.

According to one aspect, a method is provided for operating a flow meter. The method comprises the steps of: associating a first zero offset value with a first temperature sensor signal value; storing the first zero offset value associated with the first temperature sensor signal value in the meter electronics. Relating the second zero offset value to the second temperature sensor signal value and storing the second zero offset associated with the second temperature sensor signal value in the meter electronics.

  Preferably, the method for operating the flowmeter comprises the steps of: measuring the operating temperature of the flowmeter; comparing the operating temperature with at least a first zero offset value and a second zero offset value; The steps of retrieving the correspondingly closest stored zero offset value, applying the closest stored zero offset value corresponding to the operating temperature to the operating routine, corrected for the operating temperature, Outputting the adjusted flow meter measurement.

FIG. 5 shows a vibratory sensor assembly according to an embodiment of the present invention. FIG. 1 shows a fuel system according to an embodiment of the present invention. FIG. 7 shows a meter electronics according to an embodiment of the invention. 5 is a flow diagram illustrating a zero difference routine according to one embodiment of the present invention. 5 is a flow chart illustrating another zero difference routine according to an embodiment of the present invention. FIG. 7 is a flow diagram illustrating yet another delta zero routine according to an embodiment of the present invention. 5 is a flow chart illustrating an actuation routine according to an embodiment of the present invention. FIG. 5 is a flow chart illustrating flow meter operation according to one embodiment of the present invention.

  FIGS. 1-8 and the following description teach one of ordinary skill in the art how to make and use the best mode of the present invention by way of specific examples. Some conventional aspects have been simplified or omitted in order to teach the principles of the present invention. Those skilled in the art will appreciate variations from these examples that fall within the scope of the present invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific examples described below, but only by the claims and their equivalents.

FIG. 1 shows an example of a flow meter 5 in the form of a Coriolis flow meter comprising a sensor assembly 10 and one or more meter electronics 20. One or more meter electronics 20 are coupled to the sensor assembly 10 to measure the characteristics of the flowing material, such as, for example, density, mass flow, volumetric flow, total mass flow, temperature, and other information.

Sensor assembly 10 includes a pair of flanges 101 and 101 ', manifolds 102 and 102', and conduits 103A and 103B. Manifolds 102, 102 'are secured to opposite ends of conduits 103A, 103B. The flanges 101 and 101 'in this example are secured to the manifolds 102 and 102'. Manifolds 102 and 102 ′ in this example are affixed to opposite ends of spacer 106. Spacer 106 maintains a space between manifolds 102 and 102 'in this example to prevent unwanted vibrations in conduits 103A and 103B. Conduits 103A and 103B extend outwardly from the manifold in an essentially parallel fashion. When the sensor assembly 10 is inserted into a piping system (not shown) carrying a flowing substance, the substance enters the sensor assembly 10 through the flange 101 and the total amount of substance is the conduit 103A.
And 103B and through conduits 103A and 103B and back into the outlet manifold 102 'where the substance exits the sensor assembly 10 through the flange 101'.

  Sensor assembly 10 includes a driver 104. The driver 104 is secured to the conduits 103A and 103B in a position where it can vibrate the conduits 103A, 103B in the drive mode. More specifically, driver 104 includes a first driver component (not shown) secured to conduit 103A and a second driver component (not shown) secured to conduit 103B. The driver 104 can comprise one of many known arrangements, such as a magnet mounted to the conduit 103A and an opposing coil mounted to the conduit 103B.

In this example, the drive mode is the first out-of-phase bending mode, and conduits 103A and 103B have approximately the same mass distribution, moment of inertia, and elastic coefficients around bending axes WW and W'-W ', respectively. Preferably selected and appropriately mounted on the inlet manifold 102 and the outlet manifold 102 'to provide a balanced system. In this example where the drive mode is the first out of phase bend mode, conduits 103A and 103B are driven by driver 104 in a relative direction about their respective bend axes WW and W'-W '. A drive signal in the form of an alternating current may be provided by one or more meter electronics 20, for example via a passage 110, etc. to pass through the coil and cause both conduits 103A, 103B to vibrate. One skilled in the art will appreciate that other drive modes may be used within the scope of the present invention.

The illustrated sensor assembly 10 includes a pair of pickoffs 105, 105 'secured to the conduits 103A, 103B. More specifically, a first pickoff component (not shown) is positioned on conduit 103A and a second pickoff component (not shown) is positioned on conduit 103B. In the illustrated embodiment, the pickoffs 105, 105 'may be electromagnetic detectors, eg, pickoff magnets and pickoff coils, that produce pickoff signals representing the velocity and position of the conduits 103A, 103B. For example, pickoffs 105, 105 'may provide pickoff signals to one or more meter electronics via paths 111, 111'. Those skilled in the art will appreciate that the operation of conduits 103A, 103B is proportional to the specific characteristics of the flowing material, such as the mass flow rate and density of the material flowing through conduits 103A, 103B.

  Although the sensor assembly 10 described above comprises a dual flow conduit flow meter, it should be understood that implementing a single conduit flow meter is well within the scope of the present invention. Furthermore, although the flow conduits 103A, 103B are shown as curved flow conduit configurations, the present invention may be practiced with flow meters comprising linear flow conduit configurations. Accordingly, the particular embodiments of sensor assembly 10 described above are merely exemplary and should not limit the scope of the present invention in any way.

In the example shown in FIG. 1, one or more meter electronics 20 receive pickoff signals from pickoffs 105, 105 '. Path 26 provides input and output means that allow one or more meter electronics 20 to interface with an operator. One or more of the meter electronics 20 may, for example, characterize the flowing material, such as phase difference, frequency, time delay, density, density, mass flow, volumetric flow, total mass flow, temperature, meter verification and other information. taking measurement. More specifically, one or more meter electronics 20 receive one or more signals from one or more temperature sensors 107 such as, for example, pickoffs 105, 105 'and a resistance temperature device (RTD). Use this information to measure the characteristics of the flowing material.
Techniques in which vibrating sensor assemblies, such as Coriolis flowmeters or densitometers, measure the characteristics of the flowing material are well understood, and thus detailed discussion is omitted to simplify the present description.

式中

は、質量流量であり、
FCFは、流れ較正係数であり、
Δt_measuredは、測定された時間遅延であり、
Δt₀は、初期のゼロオフセットである。 As briefly discussed above, one issue associated with sensor assemblies such as Coriolis flowmeters is zero offset, which is the measured time delay of pickoffs 105, 105 'when fluid flow is zero. It is an existence. If the zero offset is not taken into account when calculating the flow rate and various other flow measurements, the flow measurements usually include errors. The usual prior art approach to compensate for zero offsets is to measure the initial zero offset (Δt ₀ ) during the initial calibration process, which typically closes the valve and causes a zero flow reference condition. To bring about. Such calibration processes are generally known in the art, and the detailed discussion is omitted for the sake of brevity. In operation, after the initial zero offset is determined, the flow measurement is corrected by subtracting the initial zero offset from the measured time difference according to equation (1).

In the ceremony

Is the mass flow,
FCF is the flow calibration factor,
Δt _measured is the measured time delay,
Δt ₀ is the initial zero offset.

  It should be understood that equation (1) is provided as an example only and should not limit the scope of the present invention in any way. Although equation (1) is provided to calculate mass flow, it should also be understood that various other flow measurements may be affected by the zero offset and thus also corrected.

While this approach can provide satisfactory results in situations where the operating conditions are approximately the same as those present during initial calibration and determination of the zero offset Δt ₀ , in many situations it is in use. The operating conditions are quite different from the operating conditions present during calibration. As a result of the change in conditions, the vibratory flow meter may encounter drift at zero offset. These problems are particularly pronounced in shipping applications that use fuels that require widely different operating temperatures, such as MDO and HFO. In other words, the zero offset may vary from the initially calculated zero offset Δt ₀ . Drift at zero offset severely affects the performance of the sensor, resulting in inaccurate measurements. This is because, in the prior art, the zero offset used to compensate for the time difference measured during operation contained only the initially calculated zero offset without considering changes in the zero offset. . Other prior art approaches have required manual recalibration of the sensor. Typically, recalibration requires stopping flow through the sensor and zeroing the sensor again, which is not generally practical for shipping fuel system applications. Also, when the flow is stopped and a prior art zero calibration is performed, the temperature of the meter may change rapidly if the ambient temperature differs from the fluid temperature. This can result in unreliable zero calibration.

FIG. 2 shows a fuel system 200 according to one embodiment. Although system 200 is shown as a conventional shipping fuel system, it should be understood that the fuel is only an example and that system 200 is equally applicable to other fluids. Thus, the use of fuel should not limit the scope of the present invention. Fuel is stored in the main tanks 202, 204. In one example of one embodiment, the HFO is stored in the first main tank 202 and the MDO is stored in the second main tank 204. Main tanks 202, 204 are fed into day tank 206 through fuel lines 203 and 205 respectively. The day tank 206 is usually sized to store a limited amount of fuel for safety and pollution purposes. The day tank 206 minimizes the risk of fire or explosion by ensuring that there is not too much fuel stored in areas such as the ship's engine room. In the event of a fire, limiting the fuel that can be used reduces the severity of the fire-related accident. Additionally, day tank 206 receives fuel that was supplied to but not utilized by engine 208 so return fuel is returned to the day tank through another fuel line 207. Although the system 200 shows only one fuel outlet 222 and two flow meters 214, 216, it should be understood that in some embodiments there are multiple fuel outlets and more than two flow meters. .

In operation, fuel is generally recirculated from the day tank 206 to the engine 208 or other fuel consuming device, and all unconsumed fuel flows back to the day tank 206 in a closed loop. When the fuel in the day tank 206 runs low, the fuel from the main tanks 202, 204 refills the day tank 206. The pump 210 provides the operation necessary to pump fuel from the day tank 206 back to the engine 208. In-line preheater 212 heats the fuel to a temperature that is ideal for the fuel being utilized by engine 208. For example, the operating temperature of HFO is usually between about 120 and 150 <0> C, while the MDO / MFO is ideally about 30 to 50 <0> C.
The appropriate temperature for a particular fuel allows to control the viscosity of the fuel and keep it in the ideal range. The kinematic viscosity of the fuel is a measure of the flowability at a particular temperature. The viscosity of the fuel decreases with increasing temperature, so the viscosity at the moment the fuel leaves the engine's fuel injector (not shown) is the range defined by the engine manufacturer to create an optimal fuel spray pattern. It must be within. Viscosities that deviate from the specification lead to combustion failure, power loss and potential deposit formation. The preheater 212 makes it possible to obtain an optimum viscosity when correctly set for the particular fuel being used.

In-line flow meters, for example, are used to measure flow parameters such as mass flow. A supply flow meter 214 is located upstream of the engine 208 while a return flow meter 216 is located downstream of the engine 208. Since the engine 208 does not use all of the fuel provided to the engine in a common fuel rail system (not shown), excess fuel is stored in the day tank 206.
And through the closed loop circuit 218. Thus, a single flow meter does not provide accurate flow measurements, particularly in relation to engine fuel consumption, and thus the flow meters on the supply side 214 and the return side 216 (upstream and downstream of the engine 208, respectively) Need both. According to one embodiment, the difference in flow rates measured by flow meters 214, 216 is approximately equal to the flow rate of fuel being consumed by engine 208. Thus, the difference in the measured flow rate between the flow meters 214, 216 is the value of interest in most applications similar to the configuration shown in FIG. However, it should be noted that the common rail fuel system serves only as an example and does not limit the scope of the claimed invention. Other fuel systems in which fuel is returned and / or recirculated are contemplated.

式中、

は、基準質量流量であり、

は、較正される流量計の質量流量であり、
Δt_0Cは、較正される流量計の初期のゼロオフセットであり、
Δt_Eは、差分誤差であり、
Δt_cは、較正される流量計の測定された時間遅延であり、
FCF_Cは、較正される流量計の流れ較正係数である。 Because multiple flow meters 214, 216 are used, it is essential for accuracy that each meter set the zero offset correctly, as described in the above description and equation (1). Even more important is that both meters 214, 216 are adjusted to have a zero point set relative to each other, which is referred to as a difference zero. For example, in the absence of consumption (i.e., engine 208 is off and fuel is pumped through both flow meters 214, 216 in closed loop circuit 218), the flow meter shows a theoretical zero consumption state. There must be. The differential zero offset includes the flow meter's initial zero offset combined with the differential error between two or more flow meters. A differential zero offset may be required to generate approximately equal flow rates through the flow meter of interest and the reference flow meter. In other words, by referring to equation (1) above, if the same fluid flow is flowing through the flow meter being calibrated and the reference flow meter, then the two flow meters will have an equation (1) for each flow meter. Two mass flow can be generated using 1). If it is assumed that the mass flow rate of the reference flow meter is equal to the mass flow rate of the meter being calibrated, then a differential zero offset of the flow meter being calibrated can be calculated. This method finds a new zero offset that reflects the reference flow rate for the flow meter being calibrated. This new zero offset is essentially a differential offset. This is shown in equations (2)-(4).

During the ceremony

Is the reference mass flow,

Is the mass flow of the flow meter being calibrated,
Δt _{0 C} is the initial zero offset of the flow meter being calibrated,
Δt _E is a difference error,
Δt _c is the measured time delay of the flow meter being calibrated,
FCF _C is a flow calibration factor of the flow meter being calibrated.

式中、
Δt_Dは、差分ゼロオフセットである。
従って、特定の関心対象の流量計オフセットは、これが、ゼロ流量を基準とする意味での絶対ゼロオフセットではなく、ゼロオフセットは、これが２つの流量計214、216間の相違を考慮に入れるという点で差分ゼロオフセットを含む。この差分オフセットが特徴付け
られ、解消されたとき、この流量計の対の示差測定法のパフォーマンスは、大きく改良される。方程式(４)は、流れ較正係数または初期のゼロオフセット値などの特定の値が一定のままであると仮定することにより、多くの方法においてさらに簡単にすることができることを理解されたい。従って、方程式(４)の特定の形態は、本発明の範囲を限定するべきではない。 Equation (3) can be further simplified by combining the zero offset and differential error of the flow meter being calibrated. The result is an equation defining a differential zero offset, which is shown in equation (4).

During the ceremony
Δt _D is a differential zero offset.
Thus, the flow meter offset of particular interest is not an absolute zero offset in the sense that it is based on a zero flow, and the zero offset takes into account the difference between the two flow meters 214, 216. Contains a differential zero offset. When this differential offset is characterized and resolved, the performance of this flow meter pair differential measurement is greatly improved. It should be understood that equation (4) can be further simplified in many ways by assuming that certain values, such as flow calibration factors or initial zero offset values, remain constant. Thus, the particular form of equation (4) should not limit the scope of the present invention.

In the configuration of system 200, it is desirable to size the flow meter so that the pressure drop is very small, ie, the flow is relatively small relative to the size of the flow meter. At such low flow rates, the time delay between pickoffs is also relatively small. With the measured time delay very close to zero offset, the flow meter's zero offset can have a serious impact on the meter's accuracy. As the sensitivity to zero offset in system 200 increases, it can be readily appreciated that small drifts of zero offset can also adversely affect the overall system.

The absolute zero offsets of the individual flowmeters 214, 216 are not required to correct the measurements, as the difference in measurements is the value of interest. As an example, the return flow meter 216 can be a reference to the supply flow meter 214. Thus, in embodiments where the zero offset includes a differential zero offset, one of the flowmeters is considered a reference flowmeter, where the zero offsets of the other flowmeters are calibrated to match the reference meter . Thus, the differential zero offset may be calculated using at least equation (3).
Given the wide range of operating temperatures within the dual fuel system, embodiments of system 200 may characterize differential offsets over a range of operating temperatures in order to achieve a higher level of accuracy. is necessary.

FIG. 3 shows a meter electronics 20 according to one embodiment of the present invention. The meter electronics 20 can include an interface 301 and a processing system 303. Processing system 303 may include storage system 304. Storage system 304 may comprise internal memory, or alternatively may comprise external memory. The meter electronics 20 can generate the drive signal 311 and provide the drive signal 311 to the driver 104. Additionally, meter electronics 20 may receive sensor signals 310, such as pickoff / velocity sensor signals, strain signals, optical signals, or any other signal known in the art from flow meters 214, 216. Can. In some embodiments, sensor signal 310 may be received from driver 104. The meter electronics 20 can operate as a densitometer or can operate as a mass flow meter, including operating as a Coriolis flow meter. It should be understood that the meter electronics 20 can also operate as other types of vibratory sensor assemblies, and the particular example provided should not limit the scope of the present invention. The meter electronics 20 can process the sensor signal 310 to obtain flow characteristics of the material flowing through the flow conduits 103A, 103B. In some embodiments, the meter electronics 20 can receive the temperature signal 312 from, for example, one or more RTD sensors or other temperature sensors 107.

Interface 301 may receive sensor signal 310 from driver 104 or pickoffs 105, 105 'via leads 110, 111, 111'. The interface 301 can perform any necessary or desired signal conditioning such as initialization, amplification, buffering, etc. in any manner. Alternatively, some or all of the signal conditioning may be performed within the processing system 303. In addition, interface 301 may enable communication between meter electronics 20 and external devices. Interface 301 may enable electronic communication, optical communication, or wireless communication in any manner.

The interface 301 of one embodiment can include a digitizer 302, wherein the sensor signal comprises an analog sensor signal. Digitizer 302 can sample and digitize the analog sensor signal to produce a digital sensor signal. Digitizer 302 can also perform any required decimation where the digital sensor signals are decimated to reduce the amount of signal processing required and to reduce processing time.

Processing system 303 may direct the operation of meter electronics 20 to process flow measurements from sensor assembly 10. The processing system 303 has a zero consumption capture routine 313, a zero difference routine 314, a general actuation routine 315, and a fuel type signal routine to produce one or more flow measurements that compensate for drift in the flow meter's zero offset. One or more processing routines, such as 316, may be performed to process flow measurements.

According to one embodiment, meter electronics 20 may be configured to measure flow through supply flow meter 214 and return flow meter 216 as part of zero consumption capture routine 313. This is done when the engine 208 is not operating but fuel is passing through the closed loop circuit 218. According to one embodiment, the meter electronics 20 also measures and stores the temperature signal 312,
This temperature can also be related to the flow rate captured at that temperature.

As an example of the zero consumption capture routine 313, the system 200 can include a supply flow meter 214 and a return flow meter 216, each having (or sharing) meter electronics 20. Meter electronics may communicate with one another via interconnect 220 if not shared. The return flow meter 216 can, for example, generate a consumption output, such as a differential mass flow rate or a total differential mass flow rate, as part of the actuation routine 315. In one embodiment of the actuation routine 315, the return flow is subtracted from the supply flow, thereby providing a consumption measurement. Meter electronics 20 subtracts the two absolute flow signals to produce a differential output, taking into account any and all signal processing delays between the meters.

The zero consumption capture routine 313 senses when the engine 208 is off and fuel is traveling in the closed loop circuit 218. In this case, the temperature signal 312 is stored and the difference in zero consumption flow is also stored and calculated as part of the difference zero routine 314. The difference zero is
This improves the differential flow calculations performed between the two meters as this reduces the temperature effects between the meters. This eliminates the need to perform a zeroing procedure prior to operation. In the example, when the engine is off, the flow through both flow meters 214, 216, 1000 kg / hr is still present for the purposes of example. None of the meters will probably read exactly 1000 kg / hr. Instead, one reads 999 kg / hr and the other reads 1001 kg / hr, so the user
Find the 2 kg / hr consumption (or production) measurement when the engine is off. This error of 2 kg / hr leads to major differences over long-term operation. Thus, at a particular temperature, a differential zero of 2 kg / hr is stored in the meter electronics and utilized in the general operating routine 315 as a correction for any flow measurement.

Processing system 303 may comprise a general purpose computer, a micro processing system, logic circuitry, or some other general purpose or customization processing device. Processing system 303 may be distributed among multiple processing devices. Processing system 303 may include any form of integrated or stand-alone electronic storage medium, such as storage system 304.

The processing system 303 processes, among other things, the sensor signal 310 to generate the drive signal 311. Drive signal 311 is provided to driver 104 to vibrate associated flow tube (s) such as flow tubes 103A, 103B of FIG.

It should be understood that the meter electronics 20 may include various other components and functions generally known in the art. These additional features are omitted from the present description and figures for the sake of brevity. Thus, the present invention should not be limited to the specific embodiments shown and discussed.

The processing system 303 may generate errors by, for example, changes or drifts in the vibratory flow meter's zero offset, more specifically the vibratory flow meter's zero offset, to produce various flow features such as mass flow or volumetric flow. May be associated with the generated flow rate. Although the zero offset is usually calculated initially as described above, the zero offset is due to several factors, including changes in one or more operating conditions, particularly the temperature of the vibratory flow meter. It may deviate from the value calculated initially. The change in temperature may be due to a change in fluid temperature, a change in ambient temperature, or both. In system 200, preheater 212 is primarily responsible for the temperature of the fluid received by flow meter 214,216. The change in temperature probably deviates from the sensor's reference or calibration temperature T ₀ during the determination of the initial zero offset. According to one embodiment, the meter electronics 20 can implement the zero difference routine 314 as described further below.

FIG. 4 is a flow diagram illustrating an embodiment of executed routines, such as the zero consumption capture routine 313 and / or the zero difference routine 314. System 200 executes at a point in time in closed loop zero consumption state 400. Under such conditions, each of the supply flow meter 214 and the return flow meter 216 encounter fluid flow, but the engine 208 or other fuel consuming device is not operating. Thus, no fuel is consumed and the measured flow between the flow meters 214, 216 should be the same. The flow through the flow meters 214, 216 is then measured at step 402, and the temperature of at least one of the flow meters 214, 216 is also measured at step 404. At step 402, the received sensor signal may be processed to determine a first flow rate determined by the supply flow meter 214 and a second flow rate determined by the return flow meter 216. The first and second flow rates may be determined, for example, using equation (1). The received sensor signal may be received during normal operation, for example, while fluid is flowing through the flow meter 214, 216. The sensor signals can include time delays, phase differences, frequencies, temperatures, and the like. The sensor signals may be processed to determine one or more operating conditions. The one or more current operating conditions can include temperature, fluid density, pressure, drive gain, and the like.

The temperature may be determined by processing the sensor signal received at step 404. Alternatively, one or more operating conditions may be determined from an external input value, such as an external temperature sensor (not shown). The temperature may be determined, for example, using an RTD. The temperature is
For example, flow meter temperature or meter electronics temperature can be accommodated. According to one embodiment of the invention, the temperature is assumed to be approximately the same between the flow meters 214, 216. According to another embodiment of the present invention, it is assumed that the difference in temperature between the flow meters 214, 216 remains approximately constant. In one embodiment, each flow meter 214, 216 comprises a separate temperature sensor. In one embodiment, separate temperatures are determined for each flow meter 214, 216, and the temperatures are averaged for calculation purposes. In one embodiment, separate temperatures are stored in each flow meter 214
, 216 and each measured temperature is input into the meter electronics 20.
In one embodiment, separate temperatures are determined for each flow meter 214, 216, and a single temperature is used for calculation purposes.

One or more sensor signals may be received from the flow meter 214, 216. The sensor signal may be received, for example, by pickoffs 105, 105 'of the supply flow meter 214. As there are multiple flow meters, such as in FIG. 2, pickoff signals may be received from both as fluid flows through the flow meters 214, 216. By using the same or similar equations described above, a differential zero value is calculated at step 406, which is stored within meter electronics 20 at step 408. The difference zero value and the corresponding temperature may be stored in various forms, including, for example, look-up tables, graphs, equations, etc., electronic device 20, local hardware, software, or remote hardware / computing device (shown) May be stored.

  According to one embodiment of the present invention, the differential zero offset may be determined, for example, using equations (2)-(4). According to one embodiment of the present invention, the determined zero offset can include the initially determined zero offset. This may be the case, for example, if the routines of FIGS. 4-6 are implemented as part of an initial calibration of a vibratory flow meter. According to another embodiment of the present invention, the determined zero offset can include the subsequently determined zero offset. The subsequently determined differential zero offset may be different from the initially determined zero offset. This may in particular apply, for example, to situations where the operating conditions are different from the operating conditions when the initial zero offset was determined.

FIG. 5 is also a flow chart illustrating an embodiment of executed routines such as the zero consumption capture routine 313 and / or the zero difference routine 314. As in the other embodiments described, the system 200 performs at step 400, at some point, in a closed loop zero consumption state. Under such conditions, each of the supply flow meter 214 and the return flow meter 216 encounter fluid flow, but the engine 208 or other fuel consuming device is not operating. Thus, no fuel is consumed and the measured flow between the flow meters 214, 216 should be the same. The flow through the flow meters 214, 216 is then measured at step 402, and the temperature of at least one of the flow meters 214, 216 is also measured at step 404. By using the same or similar equations described above, a difference zero value is calculated based on the measured temperature at step 500. The difference zero value is stored in meter electronics 20 at step 504 and associated with the measured temperature at step 508. If multiple difference zeros are measured for a given temperature, the multiple values are averaged at step 506 to produce an average difference zero. The averaged difference zero is then associated with the given temperature at step 508 and recorded in the meter electronics 20.

FIG. 6 is a flow chart illustrating a related embodiment of the routine. As in the other embodiments described, the system 200 performs at step 400, at some point, in a closed loop zero consumption state. Under such conditions, each of the supply flow meter 214 and the return flow meter 216 encounter fluid flow, but the engine 208 or other fuel consuming device is not operating. Thus, no fuel is consumed and the measured flow between the flow meters 214, 216 should be the same. The flow through the flow meter 214, 216 is then measured in step 402 and the flow meter 214, 216
The temperature of at least one of is also measured at step 404. By using the same or similar equations as described above, the difference zero value is
Calculated based on the measured temperature. The difference zero value is stored in the meter electronics 20 and associated with the measured temperature at step 502. If multiple difference zeros for a given measured temperature are stored, statistical analysis known in the art determines at step 600 the presence of any outliers to discard. Apply to multiple differential zeros. Outliers are difference zeros that differ significantly from most of the other difference zeros measured for a given temperature. These values are outside the overall data trending range that exists and are a source of inaccuracies. Such statistical analysis may be performed, for example, but not limited to, mean, median, standard deviation, correlation coefficient, Chauvenet's criterion, Dixon's Q test, for outliers. Grubbs test for outliers, interquartile analyzes, Mahalanobis distance calculations, modified Thompson tau test, Pierce's criterion, and the art Including any other statistical test known. An average is calculated at step 602 for the plurality of difference zero values that were not discarded. This average is then stored in the meter electronics at step 604. Such statistical analysis may also be part of the zero consumption capture routine 313 and / or the zero difference routine 314.

  Advantageously, compensating for the differential zero offset between two or more meters not only compensates for condition-based zero differences in operation, but also for example any absolute zero offset differences between meters due to installation effects remove. Furthermore, the differential zero offset need not necessarily be determined when the flow rate through the flow meter is zero, as long as the fluid flowing through the flow meter of interest and the reference flow meter has approximately the same fluid flow rate. Thus, a differential zero offset may be determined, for example, whenever the engine is off. However, this assumes that the difference between the measured flow rates is due to the change in zero offset and is not attributable to other factors such as a change in flow calibration factor. The routines of FIGS. 4 to 6 may be performed by the manufacturer or by the user after attaching the sensor. Also, the routines of FIGS. 4-6 may be performed when the flow rates through the two or more flow meters 214, 216 are approximately the same, including zero fluid flow rates.

The routines illustrated by FIGS. 4 to 6 may be performed when a fluid consuming device such as an engine is off. In other embodiments, the routine may be performed when the flow rates measured by flow meter 214, 216 are expected to include the same measurement, such as during closed loop operation. Thus, it should be understood that the flow through the flowmeters 214, 216 does not necessarily include zero flow, and in many embodiments does not include zero flow during the routine illustrated by FIGS.
According to one embodiment of the present invention, the differential zero consumption capture routine 313 may be performed after the initial calibration of the vibratory flow meter, or constitute part of the initial calibration of the vibratory flow meter Can. The zero consumption capture routine 313 may be used to generate a correlation between the zero offset of the vibratory flow meter and one or more operating conditions of the vibratory flow meter. Zero offsets can include absolute zero offsets or differential zero offsets, as described above.

After the differential zero offset is associated with a particular temperature, the measured operating temperature determines the appropriate zero offset and that zero offset stored in the meter electronics 20 for application to the flow determination equation It can be compared to the temperature associated with. According to one embodiment of the present invention, the corrected differential zero offset can result in a more accurate determination of the various flow features, whereby the meter electronics 20 corrects the corrected flow measurements / features. Can be output. In one embodiment, the corrected differential zero offset can provide a more accurate determination of engine fuel consumption.

According to one embodiment of the present invention, the zero offset determined by the routine illustrated by FIGS. 4 to 6 is used during normal operation to determine a differential zero, as illustrated by the routine illustrated in FIG. can do. More specifically, the zero offset is to determine a differential zero offset based on the measured operating temperature between the supply flow meter 214 and at least a second flow meter, such as the return flow meter 216. It can be used.

In yet another embodiment, as shown in FIG. 7, the system 200 is operated to consume fluid at step 700 and can include an embodiment of a general actuation routine 315.
In one embodiment, the engine 208 is disposed between at least two flow meters 214, 216;
The fluid consumed is fuel for the engine 208. The flow of fluid through the two flow meters 214, 216 is measured at step 702 and, similarly, at least one temperature of the flow meter is measured at step 704. The meter electronics 20 determines at step 706 whether there is a stored difference zero value corresponding to the measured temperature measured by at least one of the flow meters 214, 216. If the stored difference zero value is associated with the temperature of at least one of the flow meters 214, 216, this difference zero value is applied to the flow calculation at step 708. The rate of engine fuel consumption may then be compared at step 710 with fluid flow measurements between the supply flow meter 214 and the return flow meter 216 using any known fluid consumption equation. It is calculated. The adjusted engine fluid consumption corrected by applying the appropriate stored difference zero value is then output at step 712. However, as measured by at least one of the flow meters 214, 216,
If there is no stored difference zero value corresponding to the temperature 706, at least two closest stored difference values are identified at step 714. A theoretical zero difference value is then calculated at step 716 by interpolation or extrapolation using at least two of the closest stored difference values corresponding to the measured temperature. This logical difference zero is then applied at step 718 to the flow rate calculation. As noted above, then the rate of engine fuel consumption may be compared between the supply flow meter 214 and the return flow meter 216 for fluid flow measurements using any known fluid consumption equation. Calculated by 710. The adjusted engine fluid consumption corrected by applying the appropriate stored difference zero value is then output 712. It should be understood that in many situations, the correct measured operating conditions may not be stored as correlation values. For example, if the measured operating conditions include a temperature of 20 ° C. and the stored zero offset has corresponding zero offset values of temperatures of 10 ° C. and 30 ° C., then a suitable differential zero offset value is It can be interpolated from two available temperatures.

Zero difference routine 314 may be implemented to calibrate the difference zero offset between two or more flow meters. Thus, the zero difference routine 314 does not necessarily calibrate the flow meter to read the correct absolute mass flow rate, and the flow meter may be calibrated so that the differential reading between the two is accurate. As an example, if the true flow rate through the supply flow meter 214 is 2000 kg / hour and the flow rate of fluid through the return flow meter 216 includes 1000 kg / hour, as determined by the tester or similar device. , It is desirable to have the difference between the supply flow meter 214 and the return flow meter 216 equal to 1000 kg / hour. However, in many embodiments, if the supply flow meter 214 measures 2020 kg / hr flow, it may be acceptable as long as the return flow meter 216 is calibrated to read 1020 kg / hour. Thus, although the absolute flow rate through each meter may not be accurate, the differential readings are accurate, or at least within an acceptable error range. It is to be understood that the above mentioned values are only examples and that the scope of the present invention should not be limited in any way.

Advantageously, the differential zero offset may be generated using stored offset related values and measured operating conditions. Differential zero offsets may be determined without having to re-zero the vibratory flow meter. The differential zero offset may be determined without having to stop the flow of fluid. Instead, the differential zero offset can be determined simply by comparing the measured operating temperature with the stored differential zero offset related values.
In some embodiments, a fuel type signal 316 is provided to meter electronics 20. Each fuel type may have a separate associated differential zero offset and an associated temperature stored in the meter electronics.

In some embodiments, the determined operating temperature may be the same as the operating condition present during calibration or may be within its difference threshold. Thus, in some embodiments, the measured operating temperature may be compared to the initial calibration operating conditions and the associated zero offset. If the difference is less than the difference threshold, the difference zero routine may not attempt to retrieve the difference zero offset, and may use the initially calibrated zero offset.
It can be readily appreciated that the fluid consumption measurement becomes more accurate as more differential zero values are determined at different time points and at different operating temperatures.

It can also be appreciated that multiple zero offsets may be stored for each of multiple temperatures for a single flow meter application. Because the flow meter is often required to operate within a range of temperatures, the meter's zero can drift as the operating temperature changes. Thus, different zero offsets may be calculated for different temperatures, stored and stored in the meter electronics 20. For example, if the meter has a zero offset initially captured at 30 ° C. and then operated at 60 ° C., the meter may report a flow rate that is less accurate than desired. However, if the meter electronics 20 applies a captured or preset zero offset to the 60 ° C. temperature point, the flowmeter's accuracy will improve. In such cases, one or more sensor signals may be received from the flow meter 214, 216. A single meter zero offset value may be determined and stored in meter electronics 20 using the same or similar equations described above. The zero offset value is associated with the corresponding temperature which may also be stored in the meter electronics 20.

  According to one embodiment of the present invention, the zero offset can include the initially determined zero offset. This may be the case, for example, if the routine is implemented as part of the flow meter's initial calibration. According to another embodiment of the present invention, the zero offset may include the zero offset which is then determined. The subsequently determined zero offset may be different from the initially determined zero offset. This may in particular apply, for example, to situations where the operating conditions are different from the operating conditions when the initial zero offset was determined. The subsequently determined zero offset may be recorded by the user when the need arises due to changes in operating conditions.

One example of a method for operating a flow meter contemplated as one embodiment is shown in FIG. At step 800, a first zero offset value is associated with the first temperature sensor signal value. At step 802, a first zero offset value is associated with the first temperature sensor signal value and stored in the meter electronics 20. For example, various forms, including look-up tables, graphs, equations, etc., may be stored within the meter electronics 20, local hardware, software, or remote hardware / computing devices (not shown). A second zero offset value is associated with the second temperature sensor signal value in step 804 and stored in meter electronics 20 in step 806. At step 808, the operating temperature of the flow meter is measured. The temperature may be determined by processing the sensor signal. Alternatively, the temperature may be determined from an external input value, such as an external temperature sensor (not shown). The temperature may be determined, for example, using an RTD. The temperature may, for example, correspond to the flow meter temperature or the meter electronics temperature. The operating temperature is compared in step 810 to at least a first zero offset value and a second zero offset value. Although only two temperature related zero offsets are described for simplicity, many zero offsets at many temperatures are contemplated. Additionally, multiple zero offsets may be calculated for specific temperatures, and statistical analysis may be applied to these multiple measurements to reflect more accurate zero offsets for specific temperatures can do. One example, without limitation, is simple averaging. At step 812, the closest stored zero offset value corresponding to the operating temperature is retrieved. The stored stored zero offset, which is the closest to the operating temperature and is retrieved, is applied to the operating routine at step 814 and the adjusted flowmeter measurements corrected for the operating temperature are output at step 816 Be done.

The invention described above provides various methods for determining and compensating for changes that occur at differential zero offsets of vibratory flow meters, such as Coriolis flow meters. Although the various embodiments described above are directed to flow meters, in particular Coriolis flow meters, the invention is not limited to Coriolis flow meters, and the methods described herein are other types of flow meters, or Coriolis flow rates. It should be understood that it may also be used for other vibratory sensors that lack some of the measuring capabilities of the meter.

The above detailed description of the embodiments is not a complete description of all the embodiments contemplated by the inventors within the scope of the present invention. Indeed, those skilled in the art will recognize that certain elements of the above-described embodiments may be combined or eliminated in various ways to create further embodiments, and such additional embodiments are It is within the scope of the present description and the scope of the disclosure. It will also be apparent to those skilled in the art that all or part of the above embodiments may be combined to create additional embodiments within the scope and disclosure of the present invention.

  Thus, while specific embodiments of the present invention are described herein for purposes of illustration, various equivalent modifications are possible within the scope of the present application, as those skilled in the relevant art will recognize. The disclosure provided herein is applicable to other vibratory sensors and is not the only embodiment described above and shown in the accompanying drawings. Accordingly, the scope of the above embodiments should be determined from the appended claims.

Claims (20)

A method for operating a system configured to consume fluid, comprising at least two flow meters, the method comprising:
Recirculating the fluid in a closed loop having a feed flow meter and a return flow meter, such that the fluid is not substantially consumed;
Measuring the flow of fluid in the supply flow meter and the return flow meter;
Comparing fluid flow measurements between a supply flow meter and a return flow meter;
Determining a first difference zero value based on differences in fluid flow measurements between the supply flow meter and the return flow meter;
Receiving a first temperature sensor signal value;
Relating a first difference zero value to a first temperature sensor signal value;
Storing a first differential zero value associated with the first temperature sensor signal value in the meter electronics, for operating the system configured to consume the fluid. The fluid of claim 1, wherein a plurality of differential zero values are determined and stored for each of the first temperature sensor signal values at different time points and associated with the first temperature sensor signal value. A method for operating a system configured as follows. Calculating a plurality of averaged zero difference values by averaging a plurality of difference zero values;
Relating the averaged plurality of difference zero values to the first temperature sensor signal value;
Storing the averaged plurality of differential zero values associated with the first temperature sensor signal value in the meter electronics, the system configured to consume fluid according to claim 2. Way to operate. Applying statistical analysis to the plurality of difference zero values;
4. A method for operating a system configured to consume fluid as claimed in claim 3, comprising the step of: discarding outlier difference zero values. Operating the engine disposed between the supply flow meter and the return flow meter to consume the fluid;
Receiving temperature sensor signal values from at least one of the supply flow meter and the return flow meter while the engine is operating;
Measuring the flow of fluid in the supply flow meter and the return flow meter while the engine is operating;
Calculating engine fluid consumption by comparing fluid flow measurements between a supply flow meter and a return flow meter using an engine fluid consumption equation;
Applying a differential zero value associated with the temperature sensor signal in the meter electronics to the engine fluid consumption equation;
Outputting the adjusted fluid consumption measurement corrected for the operating temperature, the method for operating the system configured to consume the fluid according to claim 1. Measuring the flow of the second fluid in the supply flow meter and the return flow meter;
A second differential zero value is compared based on the difference in fluid flow measurements between the supply flow meter and the return flow meter, comparing the second fluid flow measurement between the supply flow meter and the return flow meter. Determining the
Receiving a second temperature sensor signal value from at least one of the supply flow meter and the return flow meter;
Relating a second difference zero value to a second temperature sensor signal;
Storing the second differential zero value associated with the second temperature sensor signal value in the meter electronics, and operating the system configured to consume fluid according to claim 1. the method of. Operating the engine disposed between the supply flow meter and the return flow meter to consume the fluid;
Receiving temperature sensor signal values from at least one of the supply flow meter and the return flow meter while the engine is operating;
Measuring the flow of fluid in the supply flow meter and the return flow meter while the engine is operating;
Calculating engine fluid consumption by comparing fluid flow measurements between a supply flow meter and a return flow meter using an engine fluid consumption equation;
While the engine is operating, the temperature sensor signal value received from at least one of the supply flow meter and the return flow meter is within a threshold associated with the first temperature sensor signal value in the meter electronics. Applying a differential zero value associated with the first temperature sensor signal value in the meter electronics to the engine fluid consumption equation if
While the engine is operating, the temperature sensor signal value received from at least one of the supply flow meter and the return flow meter is within a threshold associated with the second temperature sensor signal value in the meter electronics Applying to the engine fluid consumption equation a differential zero value associated with a second temperature sensor signal value in the meter electronics,
Outputting the adjusted fluid consumption measurement corrected for the operating temperature, the method for operating the system configured to consume the fluid according to claim 5. While the engine is operating, the temperature sensor signal values received from at least one of the supply flow meter and the return flow meter are combined with the first temperature sensor signal value in the meter electronics and the meter electronics in the meter electronics. Applying an interpolated zero difference value derived from the first temperature sensor signal value and the second temperature sensor signal value in the meter electronics to the engine fluid consumption equation if it is between the second temperature sensor signal value A method for operating a system configured to consume fluid according to claim 7, comprising the steps of: While the engine is operating, the temperature sensor signal values received from at least one of the supply flow meter and the return flow meter are a first temperature sensor signal value in the meter electronics and a value in the meter electronics. If it is outside the range of the second temperature sensor signal value, the extrapolated difference zero value derived from the first temperature sensor signal value and the second temperature sensor signal value in the meter electronics may be converted into an engine fluid consumption equation. A method for operating a system configured to consume fluid according to claim 7, comprising the step of applying. A method for operating a multiple fuel system comprising an engine, at least two fuel tanks each configured to contain different fuels, and at least a supply flow meter and a return flow meter,
Recirculating the first fuel type in a closed loop while the engine is not operating so that fuel is not substantially consumed;
Measuring the flow of the first fuel in the supply flow meter and the return flow meter;
A first fuel flow measurement is compared between the supply flow meter and the return flow meter, and a first differential zero value based on the difference in the fuel flow measurement between the supply flow meter and the return flow meter. Determining the
Receiving a first temperature sensor signal value;
Associating a first difference zero value with a first temperature sensor signal value and a first fuel type;
Storing in the meter electronics a first temperature sensor signal value and a first differential zero value associated with the first fuel type;
Recirculating the second fuel type in a closed loop while the engine is not operating so that fuel is not substantially consumed;
Measuring the flow of a second fuel in the supply flow meter and the return flow meter;
A second fuel flow measurement is compared between the supply flow meter and the return flow meter, and a second differential zero value based on the difference in the fuel flow measurement between the supply flow meter and the return flow meter. Determining a second temperature sensor signal value;
Relating a second difference zero value to a second temperature sensor signal value and a second fuel type;
Storing the second temperature sensor signal value and a second differential zero value associated with the second fuel type in the meter electronics, for operating the multiple fuel system. Operating the engine using the first fuel type;
Measuring at least one first operating temperature of the supply flow meter and the return flow meter;
Retrieving a first difference zero value corresponding to a first operating temperature and a first fuel type;
Applying a first difference zero value to the engine fluid consumption equation;
Outputting the adjusted fluid consumption measurement value calculated using the engine fluid consumption equation corrected for the first operating temperature and the first fuel type. Method for operating multiple fuel systems. Switching the fuel type for engine operation;
Measuring at least one second operating temperature of the supply flow meter and the return flow meter;
Retrieving a second difference zero value corresponding to a second operating temperature and a second fuel type;
Applying a second difference zero value to the engine fluid consumption equation;
Outputting the adjusted fluid consumption measurement value calculated using the engine fluid consumption equation corrected for the second operating temperature and the second fuel type. Method for operating multiple fuel systems. Meter electronics (20) for a flow meter (214, 216) including a processing system (300) coupled to a system (200) having an engine (208),
While the engine is not operating, receive sensor signals (310) from both the supply flow meter (214) and the return flow meter (216),
Determine a differential zero offset between the supply flow meter (214) and the return flow meter (216) based on the received sensor signal (310);
Determine at least one temperature of the supply flow meter (214) or the return flow meter (216);
Meter electronics (20) configured to associate a differential zero offset with temperature and to store the differential zero offset associated with temperature in the meter electronics (20). The processing system (303) determines at least one first operating temperature of the supply flow meter (214) or the return flow meter (216);
The first operating temperature is compared to one or more previous temperatures stored in the meter electronics (20),
If the previously determined zero offset is associated with the first operating temperature, the zero offset associated with the first operating temperature is adapted to apply to the calculation for determining the engine fuel consumption 14. Meter electronics (20) for the flow meter (214, 216) according to clause 13. The processing system (303) determines at least one second operating temperature of the supply flow meter (214) or the return flow meter (216);
The second operating temperature is compared to one or more previous temperatures stored in the meter electronics (20),
If the previously determined zero offset is associated with the second operating temperature, the zero offset associated with the second operating temperature is adapted to apply to the calculation for determining the engine fuel consumption Meter electronics (20) for the flow meter (214, 216) according to item 14. The processing system (303) stores a plurality of differential zero offsets associated with respective temperatures of at least one of the supply flow meter (214) or the return flow meter (216);
If the measured operating temperature is between at least two of the plurality of respective temperatures, calculating an interpolated zero offset,
14. Meter electronics for a flow meter (214, 216) according to claim 13, configured to apply an interpolated zero offset associated with a measured operating temperature in a calculation for determining engine fuel consumption. (20). The processing system (303) stores a plurality of differential zero offsets associated with respective temperatures of at least one of the supply flow meter (214) or the return flow meter (216);
If the measured operating temperature exceeds a plurality of respective temperatures, an extrapolated zero offset is calculated;
14. Meter electronics for a flow meter (214, 216) according to claim 13, configured to apply extrapolation zero offsets associated with measured operating temperatures in calculations for determining engine fuel consumption. Device (20). The flow rate of claim 15, wherein the processing system (303) is configured to switch between a plurality of stored zero offset values associated with respective stored temperatures to correspond to operating temperatures. Meter electronics (20) for the meter (214, 216). A method for operating a flow meter,
Relating a first zero offset value to a first temperature sensor signal value;
Storing in the meter electronics a first zero offset value associated with the first temperature sensor signal value;
Relating a second zero offset value to a second temperature sensor signal value;
Storing, in the meter electronics, a second zero offset associated with the second temperature sensor signal value. Measuring the operating temperature of the flow meter;
Comparing the operating temperature to at least a first zero offset value and a second zero offset value;
Retrieving the most approximate stored zero offset value corresponding to the operating temperature;
Applying the most approximate stored zero offset value corresponding to the operating temperature to the operating routine;
Outputting the adjusted flowmeter measurement corrected for the operating temperature. 20. A method for operating a flowmeter according to claim 19.

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