Method and apparatus for monitoring a liquid loading process

Abstract

The invention relates to a method and an apparatus for monitoring a loading process in which a liquid is transported from a starting container into a target container through a pipe, the method being carried out in a data-processing device and comprising the steps: (a) reading measurement values relating to the density, the pressure and / or the temperature of the liquid transported in the pipe from at least one measuring device, (b) determining an acceptable range of the density of the liquid transported in the pipe, (c) comparing the density measurement value with the acceptable range, wherein the density measurement value and / or the acceptable range are / is adjusted according to the pressure and / or temperature measurement values if required, so that they are comparable, and (d) outputting a signal if the density measurement value lies outside the acceptable range.

Description

[0001] Method and device for monitoring a liquid loading process

[0002] Description

[0003] The invention relates to a method and a device for monitoring a loading process in which a liquid is transported from a source container through a pipeline into a target container, wherein the method is carried out in a data processing device.

[0004] Loading processes, in which liquid products are conveyed from a source container through a pipeline to a destination container, are an established technique in various industries. Such loading processes are often monitored by measuring devices to ensure proper flow and to detect potential malfunctions at an early stage. One potential malfunction is the occurrence of a gas phase in a pipeline, for example, due to the evaporation of part of the liquid in the pipeline or due to the suction of a gas phase from the source container when its fill level becomes too low. State-of-the-art monitoring measures are known for detecting a gas phase or multiphase flow in a transport pipeline.

[0005] Document WO 02 / 060805 A2 describes a filling system suitable, for example, for loading liquefied petroleum gas (LPG). Using a Coriolis mass flow meter, the density of the product flowing through a pipeline is continuously determined. As soon as a significant deviation in density is detected, indicating the occurrence of multiphase flow, loading is stopped.

[0006] Document WO 2021 / 018978 A1 discloses a device for filling liquid pharmaceuticals into packaging containers. Here, too, a density measurement ensures that only liquid product, without any gaseous components, enters the packaging.

[0007] In addition to the problem of potential multiphase flow, there are other possible disruptions during the loading process of liquid products that are piped from a source container to a destination container. For example, a product other than the one intended may flow through the pipeline to the destination container, perhaps due to incorrect operation by the operating personnel or a technical malfunction. If such a mix-up occurs, the already filled product often has to be rejected and disposed of. In addition to the economic loss, there is also the risk of a hazardous condition occurring in the destination container, for example if the product is a chemical that ends up in an unsuitable destination container or is mixed with another chemical with which it can react.

[0008] The task was to improve existing loading processes to enable reliable product control that can be universally used for a wide variety of liquid substances.

[0009] This object is achieved according to the invention by a method according to claim 1 and a device according to claim 7. Advantageous embodiments of the method are specified in claims 2 to 6.

[0010] The method according to the invention for monitoring a loading process in which a liquid is transported from a source container through a pipeline to a target container is carried out in a data processing device and comprises the following steps:

[0011] (a) Reading in measured values ​​of the density and either the pressure or the temperature or the pressure and the temperature of the liquid transported in the pipeline from at least one measuring device,

[0012] (b) Determine a good range of the density of the liquid transported in the pipeline by

[0013] (b1) Reading in a good range of density or

[0014] (b2) Calculating a good range of density based on the read measured values ​​of pressure and / or temperature,

[0015] (c) comparing the density measurement with the acceptable range, adjusting the density measurement and / or the acceptable range if necessary depending on the pressure and / or temperature measurements so that they are comparable, and

[0016] (d) Output a signal when the density measurement value is outside the acceptable range.

[0017] The device according to the invention for monitoring a loading process in which a liquid is transported from a source container through a pipeline into a target container comprises a data processing device which includes:

[0018] Means for reading measured values ​​of the density and either the pressure or the temperature or the pressure and the temperature of the liquid transported in the pipeline from at least one measuring device,

[0019] Means for determining a good range of the density of the liquid transported in the pipeline, the means for determining comprising means for reading a good range of the density from an input unit and / or means for calculating a good range of the density based on the pressure and / or temperature measured values, means for comparing the density measured value with the good range, which are arranged such that the density measured value and / or the good range are adaptable depending on the pressure and / or temperature measured values, and

[0020] Means for outputting a signal when the density measurement value is outside the acceptable range.

[0021] A further subject matter of the invention is a computer program with program code which, when the computer program is executed on a suitable computer system, carries out the method according to the invention.

[0022] A further subject matter of the invention is a computer program product comprising a computer-readable medium and a computer program stored on the computer-readable medium with program code means which carry out the method according to the invention when the computer program is executed on a suitable computer system.

[0023] It has been shown that with the method and device according to the invention, the products intended for loading can be reliably identified based on their density before they enter a target container, enabling reliable monitoring of the loading process. A further advantage of the method according to the invention is the possibility of cost-effective implementation in a device according to the invention, which does not require complex measures but cleverly utilizes components frequently present in loading processes, such as sensors.

[0024] The method and device are suitable for monitoring a wide variety of loading processes. The liquids to be loaded can be non-hazardous substances such as water or food. However, they can also be hazardous substances, such as crude oil, oil fractions, gasoline, kerosene, or various liquid chemicals. The source container, pipeline, and destination container can be temperature-controlled or untemperature-controlled, for example, cooled or heated. The containers can be stationary tanks. They can also be mobile tanks and containers such as tank wagons, tank containers, tank trucks, or ships.

[0025] The same container can also be a source container or a destination container depending on whether the loading process involves refueling or defueling. In one embodiment, the loading process takes place between a stationary tank and a mobile tank, for example, a tank container. During the "refueling" loading process, the stationary tank is the source container and the mobile tank is the destination container. During the reverse loading process, "defueling," the mobile tank is the source container and the stationary tank is the destination container.

[0026] The pipeline through which the liquid is transported can be permanently connected to the source container, the destination container, or both. It can also be detachably connected to one or both of the containers. In an embodiment in which the loading process takes place between a stationary tank and a mobile tank, the pipeline is preferably permanently connected to the stationary tank and detachably connected to the mobile tank. The detachable connection can, for example, be a so-called hose connector for connecting a stationary line to a filler or drain nozzle of a mobile tank.

[0027] The method according to the invention is carried out in a data processing device; the device according to the invention comprises such a data processing device. The steps of the method and the means of the data processing device can be implemented as software components, hardware components, or combinations of hardware and software components. The data processing device can be present locally at the location of the loading process, for example, as a standalone application at a filling station. The data processing device can also be part of a more extensive automation system, for example, as a component of a programmable logic controller (PLC) or a process control system (PCS). The data processing device can be implemented as a central system or as a decentralized system distributed across multiple components that exchange data with each other.

[0028] In the first step of the method, measured values ​​of the density of the liquid transported in the pipeline are read in from at least one measuring device. Furthermore, measured values ​​of the pressure, the temperature or the pressure and temperature of the liquid transported in the pipeline are read in from at least one measuring device. The reading is carried out via means for reading measured values. The measured values ​​of the density, the pressure and the temperature can be read in from a single measuring device that is capable of recording all three measured values. The measured values ​​can also be read in from different measuring devices, for example the density from a density measuring device, the pressure from a pressure measuring device and the temperature from a temperature measuring device. Corresponding measuring devices are known in the art.In one embodiment, the density is determined metrologically in a flowmeter, preferably a Coriolis flowmeter. Means for reading measured values ​​can include any communication means via which data signals can be transmitted from a measuring device to the data processing device. These can be wired communication means, wireless communication means, or combinations thereof. The selection of the respective means depends on the requirements of the application. For example, in an application in the chemical process engineering environment, care must be taken to ensure that the communication means do not pose any danger, for example, in potentially explosive atmospheres.

[0029] In the second step of the method, a suitable range of the density of the liquid transported in the pipeline is determined. This determination can be performed in different ways. In a first variant, a suitable range of the density of the liquid transported in the pipeline is read in. The suitable range can be a single value or a range of values. The reading is performed using reading means. In one embodiment, the reading means comprise input means via which an operator can enter a value or a range of values, for example a keyboard, a control panel, a writable display, or a microphone for entering voice commands.The reading of the good area can also be done by making the good area available in another application and transmitting it to the data processing device via a communication interface, for example in applications where the data processing device is part of a more extensive automation system.

[0030] In one embodiment, in the first variant of the second step (b1) of the method according to the invention, an identification feature for the liquid transported through the pipeline is first read in by an input unit, and then, on the basis of the identification feature, the good range for the density is read out from a product database.

[0031] The identification feature can, for example, be a name or other identifying designation of the product to be loaded. It can be read in using scanning devices. The reading of the identification feature can also be performed by providing a selection of identification features, for example, as a list, and an operator selecting an identification feature from the selection.

[0032] The product database, from which the acceptable range can be read based on the identification feature, can be part of the data processing device or a separate database connected to the data processing device via a communications interface. In a second variant for determining an acceptable range for the density of the fluid transported in the pipeline, a acceptable range for the density is calculated based on the measured values ​​of pressure, temperature, or pressure and temperature read in in the first step (a). The calculation is performed using a computing device. The computing device can be a processing unit of a computer in which arithmetic and comparison operations can be performed.

[0033] The acceptable range can be calculated, for example, by first calculating a reference value for the expected density based on the measured values ​​of pressure and / or temperature. The calculation of the reference density value can be performed, for example, using the following formula:

[0034] Here, p denotes the calculated reference value of the density, T the temperature read in the first step and a, b, c, d substance-specific parameters of the liquid.

[0035] The calculation of the reference value of the density can also be carried out using the following formula:

[0036] (p + a ■ p 2 ) ■ (p — ö) = R - T

[0037] Where p denotes the calculated reference value of the density, p the pressure read in the first step, T the temperature read in the first step, a, b substance-specific parameters of the liquid and R the universal gas constant.

[0038] The substance-specific parameters can be provided in various ways. Similar to reading a pass range, the substance-specific parameters can be made available to the data processing device via means for reading them. The parameters can be entered by an operator, for example, via a keyboard, a control panel, a writable display, or a microphone for inputting voice commands. The parameters can also be provided from another application and transmitted to the data processing device via a communication interface, for example, in applications where the data processing device is part of a more extensive automation system.Similar to reading in a pass range, the substance-specific parameters can also be read out from a product database using an identification feature for the liquid transported through the pipeline, which is read in by an input unit. To get from the reference value to the pass range, for example, a predetermined value can be subtracted from the reference value to obtain the minimum value of the pass range, and a predetermined value can be added to the reference value to obtain the maximum value of the pass range. The subtracted value and the added value can be identical or different in terms of amount. Preferably, the two values ​​are identical, resulting in a symmetrical confidence interval of the pass 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.Likewise, the added value can be an absolute value, a percentage value, or a combination of an absolute value and a percentage value. For a percentage value, for example, the percentage can refer to the calculated reference value.

[0039] In the third step of the process, the measured density value is compared with the acceptable range. The comparison is performed using a comparison device. The comparison device can be a computer processing unit that can perform calculations and comparison operations.

[0040] When making the comparison, it is important to ensure that the measured density value and the acceptable range are comparable. One aspect of comparability concerns the physical unit of density and its scaling. The corresponding conversion is possible using known formulas and can be performed using the comparison tools in the data processing device. Another aspect of comparability concerns the dependence of density on other physical factors such as pressure and temperature. In cases where the read values ​​for the pressure and temperature of the fluid transported in the pipeline correspond to the values ​​for which the acceptable range was read, no adjustment measures are necessary, and the read density measured value can be directly compared with the acceptable range.In cases where the acceptable density range refers to different pressure and / or temperature values ​​than the read-in measured values, it is necessary to adjust the density measurement value and / or the acceptable range depending on the pressure and temperature measured values ​​so that they are comparable. An adjustment is necessary, for example, if the acceptable range values ​​refer to standard conditions, e.g., atmospheric pressure and a temperature of 20°C, but the read-in measured values ​​deviate from the standard conditions.

[0041] An adjustment can be made, for example, by calculating the following formula: Here, p denotes the density, T the temperature and a, b, c, d are the pacific parameters of the liquid.

[0042] An adjustment can also be made, for example, by a calculation using the following formula: (p + a ■ p 2 ) ■ (p — ö) = R - T

[0043] Here, p denotes the density, p the pressure, T the temperature, a, b the substance-specific parameters of the liquid and R the universal gas constant.

[0044] In one embodiment, in step (b1) of the method, reference values ​​for pressure and temperature assigned to the acceptable range are read in, 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. The reading of the reference values ​​can be carried out in a similar manner to the reading of the acceptable range. The reference values, like the acceptable range, can be read in from a database based on an identification feature. This can be the same database from which the acceptable range is read in. 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.

[0045] In the fourth step of the process, a signal is output if the measured density value is outside the acceptable range. The output is provided by a signal output device. As soon as the measured density value is outside the acceptable range, a loading process condition exists that requires some kind of response, as it does not correspond to the desired or specified condition. The response can be made by an operator, an automated system, or both.

[0046] In one embodiment, the output of the signal causes a visually and / or acoustically perceptible representation for an operator of the loading process. This enables the operator to react immediately to the detected departure from the goods area. Examples of means for visually and / or acoustically perceptible representation are illuminated displays on control devices, warning lights, flashing displays on screens, audio signals, and combinations thereof. The output can expediently occur wherever an operator is located during the loading process. If, for example, it is intended that the operator is located near a mobile tank as the source container or target container during the loading process, the signal is preferably output within sight and / or hearing distance of the operator in a radius of the mobile tank.The output may, for example, comprise a warning light and / or warning siren mounted near the pipeline from which the mobile tank is filled or emptied. However, if the operator is expected to be in a room, such as a control room or an office, during the loading process, the means for outputting the signal may preferably comprise displays on an operator display or optical and / or acoustic output devices in the relevant room.

[0047] The means for outputting the signal can also include applications on mobile devices such as smartphones, tablets, and wearables that an operator carries. In this case, the means additionally include communication interfaces through which the data processing device can communicate with the mobile devices.

[0048] In one embodiment, the signal in step (d) of the method comprises a control signal output to a shut-off valve, causing the shut-off valve to shut off the pipeline, thereby stopping the transport of the liquid. The means for outputting the signal in this embodiment may comprise known signal transmission means, such as wired or wireless transmission means, as well as communication interfaces between the data processing device and the shut-off valve. The shut-off valve may, for example, be a ball valve or a valve. The shut-off valve may be arranged near the source container, near the destination container, or at another location in the pipeline.This embodiment may also comprise a plurality of shut-off valves, for example a first shut-off valve near the source container and a second shut-off valve near the target container, so that immediately after detection of leaving the good area, the liquid can be enclosed in the pipeline and can flow neither into the source container nor into the target container.

[0049] Design variants in which an operator is informed visually and / or acoustically can also be combined with designs in which the pipeline is automatically shut off. For example, a visual signal can be issued on a display for the operator or a warning tone can be emitted simultaneously with the shutoff of one or more shut-off valves.

[0050] Steps (a) to (d) of the method according to the invention can be performed sequentially or partially in parallel. For example, the reading of measured values ​​according to step (a) can be performed in parallel with the reading of a good density range according to step (b1). Step (b1) can also be performed before step (a). For steps that depend on the completion of other steps, the step sequence results from the logical sequence. Example

[0051] In a chemical production facility where different variants of a product were manufactured, the manufactured products were stored in several product tanks, from which they were sequentially filled into tank cars via a pipeline. The product tanks were connected to a common pipeline and could be switched on or off using separate control valves. A Coriolis mass flow meter was installed in the pipeline, which provided not only the mass flow but also the density of the liquid flowing through it as a measured value. The pressure and temperature of the liquid flowing in the pipeline were recorded by separate sensors in the pipeline. Another control valve was located in the pipeline upstream of the outlet for the tank cars, by means of which the pipeline could be completely shut off.

[0052] The control valves, measuring devices, and sensors were connected via wired data lines to a data processing unit integrated into a process control system (PCS). The process control system included a display with input devices for operation by an operator. To start the loading process, the operator selected the product to be loaded from a list of products on the display. Based on this selection, the data processing unit initiated the reading of substance-specific parameters of the selected product from a product database connected to the data processing unit via communication technology.

[0053] After the loading process began, measurements of the density, pressure, and temperature of the liquid flowing through the pipeline were continuously recorded and transmitted to the data processing system. The recorded temperature measurement was used to calculate a suitable density range. To calculate the suitable range, a reference value for the expected density at the measured temperature was first calculated using the following formula:

[0054] In addition to the temperature measurement, the substance-specific parameters a, b, c, and d read from the product database were also used to calculate the density. Based on the calculated reference value, a fixed value of 0.001 g / cm was used to calculate the acceptable range. 3subtracted from the reference value to obtain the minimum value of the acceptable range, and added to the reference value to obtain the maximum value of the acceptable range. For test purposes, a different product was transported through the pipeline to the target container without changing the calculated acceptable range. The data processing device detected that the measured density value was outside the acceptable range and issued a signal in the form of a graphic display for the operator. At the same time, the data processing device transmitted control signals to the control valves, which then closed and shut off the pipeline. The product, whose density did not match the acceptable range, was thus trapped in the pipeline before it reached the target container and could be properly disposed of.

[0055] The reference value calculated according to the formula given above for the product A originally transported through the pipeline was 0.9201 g / cm 3 The acceptable range was defined with a lower limit of 0.9191 g / cm 3 and an upper limit of 0.9211 g / cm 3 Product B, which was transported through the pipeline for testing purposes, had a density of 0.9252 g / cm 3 The method according to the invention was able to reliably distinguish between the two products despite the very slight density difference and to detect a deviation of the measured density value from the specified acceptable range. Product A and Product B could be reliably identified, thus ruling out confusion.

Claims

Patent claims 1 . A method for monitoring a loading process in which a liquid is transported from a source container through a pipeline to a destination container, the method being carried out in a data processing device, comprising the steps: (a) Reading in measured values ​​of the density and either the pressure or the temperature or the pressure and the temperature of the liquid transported in the pipeline from at least one measuring device, (b) Determine a good range of the density of the liquid transported in the pipeline by (b1) Reading in a good range of density or (b2) Calculating a good range of density based on the read measured values ​​of pressure and / or temperature, (c) comparing the density measurement with the acceptable range, adjusting the density measurement and / or the acceptable range if necessary depending on the pressure and / or temperature measurements so that they are comparable, and (d) Output a signal when the density measurement value is outside the acceptable range.

2. Method according to claim 1, characterized in that in step (b1) an identification feature for the liquid transported through the pipeline is first read in by an input unit, and then the good range for the density is read out from a product database on the basis of the identification feature.

3. Method according to claim 1 or 2, characterized in that in step (b1) reference values ​​for pressure and temperature assigned to the good range are read in, and in step (c) the adjustment of the density measurement value and / or the good range is carried out on the basis of the pressure and temperature reference values ​​and the pressure and / or temperature measurement values.

4. Method according to one of the preceding claims, characterized in that the metrological determination of the density takes place in a flow meter, in particular in a Coriolis flow meter.

5. Method according to one of the preceding claims, characterized in that the output of the signal in step (d) causes an optically and / or acoustically perceptible representation of the loading process for an operator. Method according to one of the preceding claims, characterized in that the signal in step (d) comprises a control signal that is output to a shut-off valve, and the shut-off valve is caused by the control signal to shut off the pipeline, thereby stopping the transport of the liquid. A device for monitoring a loading process in which a liquid is transported from a source container through a pipeline to a destination container, comprising a data processing device that includes: Means for reading measured values ​​of the density and either the pressure or the temperature or the pressure and the temperature of the liquid transported in the pipeline from at least one measuring device, Means for determining a good range of the density of the liquid transported in the pipeline, the means for determining comprising means for reading a good range of the density from an input unit and / or means for calculating a good range of the density based on the pressure and / or temperature measured values, means for comparing the density measured value with the good range, which are arranged such that the density measured value and / or the good range are adaptable depending on the pressure and / or temperature measured values, and Means for outputting a signal when the measured density value lies outside the acceptable range. A computer program comprising program code that, when executed on a suitable computer system, carries out a method according to any one of claims 1 to 6. A computer program product comprising a computer-readable medium and a computer program stored on the computer-readable medium, comprising program code means that, when executed on a suitable computer system, carry out a method according to any one of claims 1 to 6.

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