Method and device for monitoring a liquid loading process

Abstract

The invention relates to a method and a device for monitoring the loading process of a liquid conveyed from a starting container through a pipeline into a target container, the method being carried out in a data processing device, the method comprising the following steps: (a) reading measurements of the density, pressure and / or temperature of the liquid conveyed in the pipeline from at least one measuring device; (b) determining an acceptable range of the density of the liquid delivered in the conduit; (c) comparing the density measurement value with an acceptable range, the density measurement value and / or the acceptable range being adjusted if necessary as a function of the pressure and / or temperature measurement value such that they are comparable; and (d) outputting a signal if the density measurement is outside the acceptable range.

Description

[0001] The present invention relates to a method and a device for monitoring the loading process of a liquid being transported from a starting container through a pipeline to a target container, wherein the method is carried out in a data processing device.

[0002] The loading process, i.e., guiding a liquid product from a starting container through a pipeline to a target container, is an established technique in various industries. Such a loading process is usually monitored by measuring devices to ensure the correct progress of the loading process and to identify possible disturbances at an early stage. One possible disturbance is the occurrence of a gas phase in the pipeline, for example, due to the evaporation of part of the liquid in the pipeline or due to the suction of the gas phase from the starting container when the filling level in the starting container is too low. Monitoring measures for detecting a gas phase or a multiphase flow in a conveying pipeline are known from the prior art.

[0003] A filling system is described in document WO 02 / 060805A2, which is suitable for, for example, loading liquefied petroleum gas (LPG). The density of the product flowing through the pipeline is continuously determined by means of Coriolis mass flow rate measurement. Once a significant deviation in density is identified (from which it can be concluded that a multiphase flow has occurred), the loading is stopped.

[0004] A device is known from document WO 2021 / 018978 A1, by means of which a liquid drug is filled into a packaging container. It is also ensured via density measurement that only a liquid product free of gas components enters the packaging.

[0005] However, in addition to the problem of potential multiphase flow, there are other possible disturbances during the loading process of a liquid product conducted from a starting container through a pipeline to a target container. Thus, for example, due to incorrect operation by an operator or due to a technical fault, a product other than the intended product may flow through the pipeline to the target container. If such an error occurs, the product that has already been filled often has to be discarded and disposed of. However, in addition to the economic loss, there is also a risk of a dangerous state occurring in the target container. For example, if the product is a chemical and enters an inappropriate target container or is mixed with another chemical, a reaction may occur with it.

[0006] The presented object itself is to improve the known loading procedure so as to achieve reliable product control, which can be generally used for various different liquid substances.

[0007] According to the present invention, this object is achieved by the method according to claim 1 and the device according to claim 7. Advantageous designs of the method are specified in claims 2 to 6.

[0008] The method according to the present invention for monitoring the loading process of a liquid being transported from a starting container through a pipeline to a target container is carried out in a data processing device, and the method comprises the following steps:

[0009] (a) Read the measured values of the density, and pressure or temperature, or pressure and temperature of the liquid being conveyed in the pipeline from at least one measuring device.

[0010] (b) Determine the acceptable range of the density of the liquid being conveyed in the pipeline by:

[0011] (b1) Reading the acceptable range of the density, or

[0012] (b2) Calculating the acceptable range of the density based on the measured values of the pressure and / or temperature read.

[0013] (c) Compare the density measurement value with the acceptable range, where the density measurement value and / or the acceptable range are adjusted according to the pressure and / or temperature measurement values if necessary so that they are comparable, and

[0014] (d) Output a signal if the density measurement value is outside the acceptable range.

[0015] The device for monitoring the loading process of a liquid being conveyed from a starting container through a pipeline to a target container according to the present invention includes a data processing device, and the data processing device includes:

[0016] - A device for reading the measured values of the density, and pressure or temperature, or pressure and temperature of the liquid being conveyed in the pipeline from at least one measuring device.

[0017] - A device for determining the acceptable range of the density of the liquid being conveyed in the pipeline, and the determining device includes a device for reading the acceptable range of the density from an input unit and / or a device for calculating the acceptable range of the density based on the pressure and / or temperature measurement values.

[0018] - A device for comparing the density measurement value with the acceptable range, and the device is configured such that the density measurement value and / or the acceptable range can be adjusted according to the pressure and / or temperature measurement values, and

[0019] - A device for outputting a signal when the density measurement value is outside the acceptable range.

[0020] Another subject of the present invention is a computer program having program code, and when the computer program is executed on a suitable computer system, the program code executes the method according to the present invention.

[0021] Another subject matter of the present invention is a computer program product having a computer-readable medium and a computer program stored on the computer-readable medium, the computer program having program code means which, when the computer program is run on a suitable computer system, execute the method according to the present invention.

[0022] It has been shown that by using the method according to the present invention and the device according to the present invention, products intended for loading can be reliably identified based on their density before they enter the target container, and on this basis the loading process can be reliably monitored. Another advantage of the method according to the present invention is that it can be implemented economically and effectively in the device according to the present invention, which does not require complex measures but uses in a skilled manner components that are usually present in the loading process, such as sensors.

[0023] The method and the device are suitable for monitoring various loading processes. The liquid to be loaded can be a safe substance, such as water or food. However, they can also be harmful materials, such as crude oil, oil fractions, gasoline, kerosene or various types of liquid chemicals. The starting container, the pipeline and the target container can be non-temperature-controlled or temperature-controlled, for example, cooled or heated. The container can be a fixed storage tank installed in place. These can also be movable storage tanks and containers, such as tank trucks, storage containers, tank lorries or ships.

[0024] The same container can also be the starting container or the target container, depending on the loading process, depending on whether the loading process involves filling or emptying. In one embodiment, the loading process takes place between a fixed storage tank and a movable storage tank (e.g., a storage container). In the loading process "filling", the fixed storage tank is the starting container and the movable storage tank is the target container. In the reverse loading process "emptying", the movable storage tank is the starting container and the fixed storage tank is the target container.

[0025] The pipeline through which the liquid is conveyed can be permanently connected to the starting container, the target container or both. It can also be detachably connected to one or both of these containers. In one embodiment where the loading process takes place between a fixed storage tank and a movable storage tank, the pipeline is preferably permanently connected to the fixed storage tank and detachably connected to the movable storage tank. The detachable connection can be, for example, a so-called hose nozzle for connecting a fixed pipeline to a filling pipe or a discharge pipe of the movable storage tank.

[0026] The method according to the invention is performed in a data processing device, and the device according to the invention includes such a data processing device. The steps of the method and the device of the data processing device can be implemented as software components, hardware components, or a combination of hardware components and software components. The data processing device can be locally present at the location of the loading process, for example, as a stand-alone application at a filling station. The data processing device can also be part of a wider automation system, for example, as a building block of a programmable logic controller (PLC) or a process control system (PCS). The data processing device can be implemented as a centralized system or a decentralized system distributed over multiple components that exchange data with each other.

[0027] In a first step of the method, measurement values of the density of the liquid conveyed in the pipeline are input from at least one measuring device. In addition, measurement values of the pressure, temperature, or pressure and temperature of the liquid conveyed in the pipeline are input from at least one measuring device. This input is performed via a device for inputting measurement values. The measurement values of density, pressure, and temperature can be input from a single measuring device capable of detecting all three measurement values. The measurement values can also be input from different measuring devices, for example, the density measurement value is input from a density measuring device, the pressure measurement value is input from a pressure measuring device, and the temperature measurement value is input from a temperature measuring device. The corresponding measuring devices are known in the prior art. In one embodiment, the metering of density is determined in a flow meter, preferably in a Coriolis flow meter.

[0028] The device for inputting measurement values can include all communication devices via which data signals can be transmitted from the measuring device to the data processing device. These devices can be wired communication devices, wireless communication devices, or a combination thereof. The selection of the corresponding device is guided by the requirements of the application. Thus, when used in the field of chemical process technology, it is necessary to ensure that, for example, the communication device does not pose a danger, for example, in an area with an explosion hazard.

[0029] In a second step of the method, an acceptable range of the density of the liquid conveyed in the pipeline is determined. The determination can be performed in various ways. In a first variant, an acceptable range of the density of the liquid conveyed in the pipeline is input. Here, the acceptable range can be a single value or a range of values. This input is performed via a device for inputting. In one embodiment, the device for inputting includes an input device via which an operator can input a value or a range of values, such as a keyboard, an operation panel, a writable display, or a microphone for inputting voice commands. The acceptable range can also be input because the acceptable range is provided in another application and transmitted to the data processing device via a communication interface, for example, in an application where the data processing device is part of a wider automation system.

[0030] In one embodiment, in a first variant of the second step (b1) of the method according to the present invention, the identification features of the liquid conveyed through the pipeline are initially input from the input unit, and then the acceptable range of the density is read from the product database based on the identification features.

[0031] The identification features can be, for example, the name of the product to be loaded or another identification name. It can be read via a reading device. The reading process of the identification features can also be performed because the selection of the identification features is provided as a list, for example, and the operator selects the identification features from the selection.

[0032] The product database from which the acceptable range can be read based on the identification features can be part of a data processing device or a separate database, and the separate database is connected to the data processing device via a communication interface.

[0033] In a second variant for determining the acceptable range of the density of the liquid conveyed in the pipeline, the acceptable range of the density is calculated based on the pressure, temperature, or the measured values of pressure and temperature read in the first step (a). The calculation is performed via a calculation device. The calculation device can be a calculation unit of a computer, in which calculation operations and comparison operations can be executed.

[0034] For example, the acceptable range can be calculated because initially a reference value of the density expected at the measured values of pressure and / or temperature is calculated based on the measured values. The calculation of the reference value of the density can be performed, for example, by a calculation operation of the following formula:

[0035]

[0036] where ρ represents the calculated reference value of the density, T represents the temperature read in the first step, and a, b, c, d represent material-specific parameters of the liquid.

[0037] The calculation of the reference value of the density can also be performed, for example, by a calculation operation of the following formula:

[0038] (p + a·ρ 2 )·(ρ - b) = R·T

[0039] where ρ represents the calculated reference value of the density, p represents the pressure read in the first step, T represents the temperature read in the first step, a, b represent material-specific parameters of the liquid, and R represents the universal gas constant.

[0040] Material-specific parameters can be provided in different ways. Similar to the reading of the acceptable range, the material-specific parameters can be provided to the data processing device via the device for reading. The parameters can be input, for example, by an operator via a keyboard, an operation panel, a writable display, or a microphone for inputting voice commands. These parameters can also be provided from another application and can be transmitted to the data processing device via a communication interface, for example, in an application where the data processing device is part of a broader automation system. Similar to the reading of the acceptable range, the material-specific parameters can also be read out from the product database by means of the identification features of the liquid conveyed through the pipe read from the input unit.

[0041] To reach the acceptable range from the reference value, for example, a predetermined value can be subtracted from the reference value to obtain the minimum value of the acceptable range, and a predetermined value can be added to the reference value to obtain the maximum value of the acceptable range. The absolute values of the subtracted value and the added value can be the same or different. Preferably, these two values are the same, thus generating a symmetric confidence interval of the acceptable range around the reference value. The subtracted value can be an absolute value, a percentage value, or a combination of an absolute value and a percentage value. Similarly, the added value can be an absolute value, a percentage value, or a combination of an absolute value and a percentage value. In the case of a percentage value, the percentage can be related to the calculated reference value, for example.

[0042] In the third step of the method, the density measurement value is compared with the acceptable range. This comparison is carried out via the device for comparison. The device for comparison can be the calculation unit of a computer, in which calculation operations and comparison operations can be performed.

[0043] In the comparison, it will be ensured that the measured value of the read density and the read acceptable range are comparable. One aspect of comparability is related to the physical unit of density and its scale. The corresponding conversion can be carried out via known formulas and can be performed by the device for comparison in the data processing device. Another aspect of comparability is related to the dependence of density on other physical factors (such as pressure and temperature). In the case where the read values of the pressure and temperature of the liquid conveyed in the pipe correspond to the read values of the acceptable range, no adjustment measures are required, and the measured value of the read density can be directly compared with the acceptable range. In the case where the acceptable range of density is related to the values of pressure and / or temperature rather than the read measured value, it is necessary to adjust the density measurement value and / or the acceptable range according to the pressure and temperature measurement values so that they are comparable. For example, if the value of the acceptable range is related to normal conditions (such as atmospheric pressure and a temperature of 20 °C), but the read measured value deviates from the normal conditions, an adjustment is required.

[0044] For example, the adjustment can be carried out by a calculation operation using the following formula:

[0045]

[0046] Wherein, ρ represents density, T represents temperature, and a, b, c, and d represent material-specific parameters of the liquid.

[0047] The adjustment can also be performed, for example, by a calculation operation of the following formula:

[0048] (p + a·ρ 2 )·(ρ - b) = R·T

[0049] Wherein, ρ represents density, p represents pressure, T represents temperature, a and b represent material-specific parameters of the liquid, and R represents the universal gas constant.

[0050] In one embodiment, in step (b1) of the method, reference values of the pressure and temperature assigned to the acceptable range are read, and in step (c), an adjustment to the density measurement value and / or the acceptable range is made based on the pressure and temperature reference values and the pressure and / or temperature measurement values. The reading of the reference values can be performed similarly to the reading of the acceptable range. The reference values can be read from a database based on identification features as the acceptable range. This can be the same database from which the acceptable range is read. However, it can also be a separate database that is connected to the product database and / or other components of the data processing device via a communication interface.

[0051] In the fourth step of the method, if the density measurement value is outside the acceptable range, a signal is output. The output is performed via a device for outputting the signal. Once the density measurement value is outside the acceptable range, the state of the loading process is given, and since this state does not correspond to the desired or predetermined state, it should be reacted to in some way. Here, the reaction can be performed by the operator, an automatic mechanism, or both.

[0052] In one embodiment, the output of the signal prompts an optically and / or acoustically perceptible display to be provided to the operator of the loading process. Thus, the operator is enabled to react immediately to the detected deviation from the acceptable range. Examples of devices for optically and / or acoustically perceptible displays are light indicators on the operating device, warning lights, flashing indicators on the display, sound signals, and combinations thereof. The output can conveniently be performed at the place where the operator stays during the loading process. For example, if it is stipulated that the operator stays near the movable storage tank that is the starting container or the target container during the loading process, the output of the signal is preferably performed within the visual range and / or the auditory range of the operator in the environment around the movable storage tank. The output can include, for example, a warning light and / or an alarm attached near the pipeline from which the movable storage tank is filled or emptied.

[0053] In contrast, if it is stipulated that the operator remains in a room (e.g., a control room or an office) during the loading process, the device for outputting a signal may preferably include an operation display in the relevant room or an indicator on an optical and / or acoustic output device.

[0054] The device for outputting a signal may also include an application on a mobile device (such as a smartphone, a tablet computer, or a wearable device) carried by the operator. In this case, the device additionally includes a communication interface via which the data processing device can communicate with the mobile device.

[0055] In one embodiment, the signal in step (d) of the method includes a positioning signal that is output to a shut-off fitting, and by means of this positioning signal, the shut-off fitting is prompted to cut off the pipeline, thereby stopping the conveyance of the liquid. In this embodiment, the device for outputting a signal may include a known signal transmission device (such as a wired transmission device or a wireless transmission device) and a communication interface between the data processing device and the shut-off fitting. The shut-off fitting may be, for example, a ball valve or a valve. The shut-off fitting may be arranged near the starting container, near the target container, or at another point on the pipeline. This embodiment may also include a plurality of shut-off fittings. For example, a first shut-off fitting near the starting container and a second shut-off fitting near the target container, such that after it is recognized that the liquid deviates from the acceptable range, the liquid can be immediately enclosed in the pipeline and neither flow into the starting container nor into the target container.

[0056] The embodiment of optically and / or acoustically notifying the operator can also be combined with the embodiment of automatically cutting off the pipeline. Thus, for example, while cutting off one or more shut-off fittings, an optical signal or a warning tone for the operator can be output on the display.

[0057] Steps (a) to (d) of the method according to the invention can be performed sequentially with respect to each other or partially in parallel with respect to each other. For example, the reading of the measured value according to step (a) can be performed in parallel with the reading of the acceptable range of the density according to step (b1). Step (b1) can also be performed before step (a). In the case of steps that depend on the completion of other steps, the step sequence is generated by a logical order.

[0058] Example

[0059] In the production operations of the chemical industry for producing different variants of products, the produced products are stored in multiple product storage tanks and are sequentially filled into tank trucks via pipelines from the multiple product storage tanks. The product storage tanks are connected to a common pipeline and can be connected or disconnected via individual positioning valves. A Coriolis mass flowmeter is arranged in the pipeline, which provides not only the mass flow rate but also the density of the flowing liquid as a measured value. The pressure and temperature of the liquid flowing in the pipeline are detected via separate sensors in the pipeline. Another control valve is positioned in the pipeline before the tank truck outlet, and the pipeline can be completely cut off by means of this control valve.

[0060] The control valve, the meter, and the sensors are connected to a data processing device via wired data lines, and the data processing device is integrated in a process control system (PCS). The process control system includes a display, and the display has an input device for operation by the operator. To start the loading process, it is stipulated that the operator selects the product to be loaded from the product list on the display screen. Based on this selection, the data processing device prompts the material-specific parameters of the selected product to be read from the product database into the data processing device, and the product database is connected for communication with the data processing device.

[0061] After the start of the loading process, the measured values of the density, pressure, and temperature of the liquid flowing through the pipeline are continuously detected and transmitted to the data processing device. The read temperature measurement value is used to calculate the acceptable range of the density. To calculate the acceptable range, initially, the reference value of the expected density at the measured temperature is calculated according to the following formula:

[0062]

[0063] In addition to the temperature measurement value, the material-specific parameters a, b, c, d read from the product database are also used to calculate the density. Starting from the calculated reference value, to calculate the acceptable range, a fixed value of 0.001 g / cm 3 is subtracted from the reference value to obtain the minimum value of the acceptable range, and this fixed value is added to the reference value to obtain the maximum value of the acceptable range.

[0064] For testing purposes, different products are conveyed through the pipeline to the target container without changing the calculated acceptable range. The data processing device identifies that the density measurement value is outside the acceptable range and outputs a signal to the operator in the form of a graphical indicator on the display. At the same time, control signals are transmitted from the data processing device to the control valves, and these control valves then close and cut off the pipeline. Thus, the products with a density not matching the acceptable range are enclosed in the pipeline before reaching the target container and can be properly disposed of.

[0065] For product A initially transported through a pipeline, the reference value calculated by the formula indicated above is 0.9201 g / cm 3 . The lower limit of the calculated acceptable range is 0.9191 g / cm 3 and the upper limit is 0.9211 g / cm 3 . The density of product B transported through the pipeline for testing purposes is 0.9252 g / cm 3 . Although the density difference between these two products is very small, the method according to the present invention can reliably distinguish these two products and identify the deviation of the density measurement value from the predetermined acceptable range. Products A and B can be reliably identified, and thus confusion can be avoided.

Claims

1. A method for monitoring the loading process of liquid being transported from a starting container through a pipeline to a target container, wherein, The method is executed in a data processing device and comprises the following steps: (a) Reading measurement values of the density and the pressure or the temperature or the pressure and the temperature of the liquid conveyed in the pipeline from at least one measuring device; (b) Determining an acceptable range of the density of the liquid conveyed in the pipeline in the following manner: (b1) Reading the acceptable range of the density, or (b2) Calculating the acceptable range of the density based on the read measurement values of the pressure and / or the temperature; (c) Comparing the density measurement value with the acceptable range, wherein the density measurement value and / or the acceptable range are adjusted according to the pressure and / or the temperature measurement value if necessary so that they are comparable; and (d) Outputting a signal if the density measurement value is outside the acceptable range.

2. The method according to claim 1, wherein In step (b1), the identification features of the liquid conveyed through the pipeline are initially read from the input unit, and then the acceptable range of the density is read from the product database based on the identification features.

3. The method according to claim 1 or 2, wherein In step (b1), the reference values of the pressure and the temperature assigned to the acceptable range are read, and in step (c), the density measurement value and / or the acceptable range are adjusted based on the pressure and temperature reference values and the pressure and / or temperature measurement values.

4. The method according to any one of the preceding claims, wherein, The metrological determination of the density is carried out in a flowmeter, in particular in a Coriolis flowmeter.

5. The method according to any one of the preceding claims, wherein, The output of the signal in step (d) causes an optically and / or acoustically perceptible display to be provided for the operator of the loading process.

6. The method according to any one of the preceding claims, wherein, The signal in step (d) includes a positioning signal which is output to a shut-off fitting and which prompts the shut-off fitting to cut off the pipeline so as to stop the conveyance of the liquid.

7. A device for monitoring a loading process of a liquid being conveyed from a starting container through a pipeline to a target container, the device comprising a data processing device which comprises: - means for reading measurement values of the density and the pressure or the temperature or the pressure and the temperature of the liquid conveyed in the pipeline from at least one measuring device; - means for determining an acceptable range of the density of the liquid conveyed in the pipeline, the determining means comprising means for reading the acceptable range of the density from an input unit and / or means for calculating the acceptable range of the density based on the pressure and / or temperature measurement values; - means for comparing the density measurement value with the acceptable range, the means being configured such that the density measurement value and / or the acceptable range can be adjusted according to the pressure and / or temperature measurement values; and - means for outputting a signal when the density measurement value is outside the acceptable range.

8. A computer program having program code which, when the computer program is executed on a suitable computer system, executes the method according to any one of claims 1 to 6.

9. A computer program product having a computer-readable medium and a computer program stored on the computer-readable medium, the computer program having program code means which, when the computer program is run on a suitable computer system, perform the method according to any one of claims 1 to 6.

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