Tank device and method for estimating a signal propagation characteristic of a material component in a

Abstract

The invention provides a tank apparatus and a method for estimating a signal propagation characteristic of a substance composition in a predefined tank portion. The tank arrangement comprises: a tank having a first tank portion and a second tank portion above the first tank portion; an inlet for receiving a substance composition; at least a first radar metrology system disposed at the tank, the first radar metrology system comprising: a first transceiver; a first transmission line probe having an impedance discontinuity spaced apart from the first probe end by a known first distance along the first transmission line probe, the first transmission line probe being arranged with a portion of the first transmission line probe extending from the first probe end to the impedance discontinuity exclusively located in the first tank portion; and first processing circuitry coupled to the first transceiver and configured to estimate a signal propagation characteristic of a substance composition within the first volume surrounding the portion of the first transmission line probe.

Description

Technical Field

[0001] The present invention relates to a tank arrangement and a method for estimating signal propagation characteristics of a material composition in a tank. Background Art

[0002] In different industrial applications, it is necessary to reliably separate different materials with different densities. As an illustrative example, the oil industry uses a so-called phase separator to separate water, oil and gas. For example, the separated water, oil and gas are output through different outlets for recycling, discharge or further refining. In this application and other applications, it is desirable to achieve a clear separation, such as avoiding an emulsion of water and oil by outputting any of the outlets intended to output water or oil. Therefore, it is necessary to enable the material composition in a predefined portion of a tank (e.g., near the bottom of the tank) to be estimated. Summary of the invention

[0003] In view of the above, it is desirable to provide an improved estimate of the signal propagation characteristics of a material component within a predefined volume in a tank. In particular, the predefined volume may be near the bottom of the tank.

[0004] According to a first aspect of the present invention, there is provided a tank device, the tank device comprising: a tank having a first tank portion defined by a first vertical distance range from the bottom of the tank and a second tank portion defined by a second vertical distance range from the bottom of the tank, the second vertical distance range only comprising distances greater than all distances within the first vertical distance range; an inlet for receiving a material component, the material component comprising at least a liquid first substance having a first density and a liquid second substance having a second density lower than the first density; at least a first radar metrology system arranged at the tank, the first radar metrology system comprising: a first transceiver for generating, sending and receiving electromagnetic signals; a first transmission line probe having a first probe end coupled to the first transceiver; The invention relates to a tank having an impedance discontinuity along a first transmission line probe spaced a known first distance from the first probe end, the first transmission line probe being arranged inside the tank so that a portion of the first transmission line probe extending from the first probe end to the impedance discontinuity is exclusively located in the first tank portion, the first transmission line probe being configured to direct an electromagnetic transmit signal from the first transceiver from the first probe end to the impedance discontinuity and to return an electromagnetic reflection signal generated by reflection of the transmit signal at the impedance discontinuity to the first transceiver; and a first processing circuit system coupled to the first transceiver and configured to estimate a signal propagation characteristic of a material component within a first volume surrounding the portion of the first transmission line probe based on a timing relationship between the transmit signal and the reflection signal and based on the known first distance.

[0005] The present invention is based on the recognition that an estimate of the propagation characteristics of a signal within a predefined level range in a tank can be used to estimate the material composition within the level range. The inventors have further recognized that if the length of the probe portion of the transmission line probe specifically located within the predefined level range (corresponding to the tank portion) along the transmission line probe is known, such an estimate of the propagation characteristics of the signal can be achieved using a transmission line probe with the probe portion, and such an estimate of the propagation characteristics of the signal can also be measured based on the relationship between the electromagnetic signal guided along the probe portion from the transceiver and the subsequent back reflection at the far end of the probe portion. In order to achieve this measurement, the inventors have found that it is beneficial if the probe portion starts with a first probe end connected to the transceiver. This provides a configuration in which the electromagnetic signal is not guided through the material composition within another level range before reaching the predefined level range spaced apart from the top plate of the tank.

[0006] Hereby, a reliable and accurate estimation of the material composition in a predefined first tank portion (eg close to the bottom of the tank) may be achieved, whereby an improved control of the tank arrangement may be provided.

[0007] The tank device may include an outlet arranged in the first tank portion for outputting a first substance separated from a substance component. The output may be controlled based on an estimated signal propagation characteristic of the substance component within a first volume surrounding a portion of the first transmission line probe such that output of the second substance through the outlet is prevented or at least minimized. This may be desirable, particularly in applications where the first substance is water and the second substance is a hydrocarbon such as oil.

[0008] In various embodiments of the tank device according to the present invention, the first transmission line probe may include a probe conductor coupled to the transceiver; and a dielectric layer at least partially surrounding the probe conductor.

[0009] The dielectric layer may advantageously form a dielectric enclosure structure extending along a majority of the transmission line probe, for example along the entire length of the transmission line probe arranged inside a tank.

[0010] This type of transmission line probe may be referred to as a partial external dielectric (PED) transmission line probe.

[0011] The propagation velocity of the probe along the PED transmission line is given by the effective dielectric constant ε eff To characterize, the effective dielectric constant ε eff Depends on the dielectric constant ε of the dielectric closed structure int and the dielectric constant ε of the surrounding medium ext The propagation speed of the electromagnetic signal (transmitted signal and reflected signal) traveling along the PED transmission line probe is the speed of light divided by ε eff The square root of is given.

[0012] The effective dielectric constant ε of the PED transmission line probe eff The dielectric constant ε of the dielectric confining structure depends at least approximately on the following relation int and the dielectric constant ε of the surrounding medium ext :

[0013]

[0014] Where α is a number between 0 and 1 indicating the degree of coupling to the surrounding medium. In the case of α=1, the probe conductor is uncoated (hence maximum influence of the surrounding medium), while in the case of α=0, the probe conductor is completely isolated from the surrounding medium (signal propagation is completely independent of the surrounding medium).

[0015] In an embodiment of the tank device according to the invention, the first transmission line probe may advantageously include a substantially uniform dielectric material coating, the thickness and material properties of which are selected to achieve a coupling coefficient α greater than 0.1 and less than 0.5, to achieve a suitable trade-off between coupling with surrounding material components and signal loss along the portion of the first transmission line probe. As an illustrative and non-limiting example, the dielectric material coating may be made of PTFE and have a thickness in the range of 1 mm to 10 mm.

[0016] In an embodiment of the tank device according to the present invention, the impedance discontinuity of the first transmission line probe of the first radar metrology system may be at a higher vertical level than the first probe end. For example, the first transmission line probe may be arranged substantially vertically, wherein the first probe end is located at the bottom of the tank. In other example configurations, the first transmission line probe may be arranged substantially horizontally.

[0017] The impedance discontinuity of the first transmission line probe of the first radar metrology system may be constituted by the second probe end of the first transmission line probe. This may provide a relatively compact and simple configuration of the first radar metrology system. As an alternative, the impedance discontinuity may be provided in the form of a structure providing the impedance discontinuity along the probe, such as a metallic reflector structure. Such a configuration may provide more detailed information about the signal propagation characteristics of the material components in the sub-volume of the first volume.

[0018] In various embodiments, the tank device can be configured as a phase separator arrangement. In such an embodiment, the tank can be long in a first direction that is substantially horizontal and extends between a first tank end and a second tank end in the first direction. The inlet can be adjacent to the first tank end. The tank can include an overflow weir arranged at a weir position between the inlet and the second tank end. The tank can include: a first outlet, which is horizontally arranged at the bottom of the tank, between the inlet and the weir position, for outputting a first substance separated from a material component; and a second outlet, which is horizontally arranged at the bottom of the tank, between the weir position and the second tank end, for outputting a second substance separated from the material component. The first radar metering system can be arranged to meter the material component at a first metering position between the inlet and the weir position.

[0019] Using information obtainable from the first radar metrology system, the operation of the phase separator arrangement may be optimized. For example, the flow rate of the material component provided to the inlet may be controlled based on the estimate of the signal propagation characteristic provided by the first radar metrology system. In particular, the estimate of the signal propagation characteristic may indicate the efficiency of the separation of the material component into the first material and the second material. If the estimate of the signal propagation characteristic indicates a separation below a predefined threshold separation, the flow rate of the material component through the inlet may be reduced, or the flow of the material component through the inlet may be temporarily stopped.

[0020] In addition, according to various embodiments, the tank device of the present invention may include a second radar metering system arranged at the tank. The second radar metering system may include: a second transceiver for generating, transmitting and receiving electromagnetic signals; a second transmission line probe having a first probe end coupled to the second transceiver, the second transmission line probe being configured to guide the electromagnetic transmission signal provided by the second transceiver from the first probe end toward the material component in the tank, and return the electromagnetic reflection signal generated by the reflection of the transmission signal at the surface of the material component to the second transceiver; and a second processing circuit system coupled to the second transceiver and configured to estimate the level of the surface of the material component based on the timing relationship between the transmission signal and the reflection signal.

[0021] The provision of this second radar gauging system provides improved process control for the tank installation.

[0022] The second transmission line probe may advantageously extend vertically to allow an external measuring unit of the second radar metrology system to be arranged on top of the tank.

[0023] In various example configurations, the second transmission line probe may have an impedance discontinuity along the second transmission line probe spaced apart from the first probe end by a known second distance, the second transmission line probe being arranged inside the tank so that a portion of the second transmission line probe extending from the first probe end to the impedance discontinuity is exclusively located in the second tank portion; and the second processing circuit system may be configured to estimate signal propagation characteristics of material components within a second volume surrounding the portion of the second transmission line probe based on a timing relationship between the transmitted signal and the reflected signal and based on the known second distance.

[0024] According to a second aspect of the present invention, there is provided a method for estimating signal propagation characteristics of a material component in a first tank portion, the first tank portion being defined by a first vertical distance range from a tank bottom, the first tank portion being below a second tank portion defined by a second vertical distance range from the tank bottom, the method comprising: providing a first transmission line probe having a first probe end and an impedance discontinuity spaced apart from the first probe end along the first transmission line probe by a known first distance, the first transmission line probe being arranged inside the tank so that a portion of the first transmission line probe extending from the first probe end to the impedance discontinuity is exclusively located in the first tank portion; generating and transmitting an electromagnetic transmit signal by a first transceiver; providing the transmit signal to the first probe end of the first transmission line probe; receiving by the first transceiver an electromagnetic reflection signal generated by reflection of the transmit signal at the impedance discontinuity of the first transmission line probe from the first transmission line probe; and estimating, by a first processing circuit system coupled to the first transceiver, the signal propagation characteristics of the material component within a first volume surrounding the portion of the first transmission line probe based on a timing relationship between the transmit signal and the reflection signal and based on the known first distance.

[0025] Further embodiments of the second aspect of the invention and the effects obtained by the second aspect of the invention are largely similar to the embodiments described above for the first aspect of the invention.

[0026] In summary, the present invention is therefore directed to a tank device comprising: a tank having a first tank portion and a second tank portion located above the first tank portion; an inlet for receiving a material component; at least a first radar metrology system arranged at the tank, the first radar metrology system comprising: a first transceiver; a first transmission line probe having an impedance discontinuity spaced a known first distance along the first transmission line probe from a first probe end, the first transmission line probe being arranged with a portion of the first transmission line probe extending from the first probe end to the impedance discontinuity, the portion being exclusively located in the first tank portion; and a first processing circuit system coupled to the first transceiver and configured to estimate signal propagation characteristics of the material component within a first volume surrounding the portion of the first transmission line probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] These and other aspects of the present invention will now be described in more detail with reference to the accompanying drawings showing example embodiments of the invention, in which:

[0028] Figure 1 A first example of a tank arrangement according to an embodiment of the invention is schematically shown;

[0029] FIG. 2A to FIG. 2B The schematic diagram shows the Figure 1 An example configuration of a first radar metrology system in a tank device;

[0030] Figure 3 A second example of a tank arrangement according to an embodiment of the present invention is schematically shown;

[0031] Figure 4 The schematic diagram shows the Figure 3 Example configuration of a second radar metering system in a tank device;

[0032] Figure 5 A third example of a tank device in the form of a phase separator arrangement according to an embodiment of the invention is schematically shown;

[0033] Figure 6 is a flow chart schematically illustrating an example of a method according to the present invention;

[0034] Figure 7 is used FIG. 2A to FIG. 2B An exemplary echo curve obtained by the first radar metrology system in; and

[0035] Figure 8 is used Figure 4 An exemplary echo curve obtained by the second radar metrology system in . DETAILED DESCRIPTION

[0036] Figure 1 A first example of a tank device 1 according to an embodiment of the present invention is schematically shown. The tank device 1 according to the first example comprises a tank 3, an inlet 5, a first radar metering system 7 and optionally an outlet 9. Figure 1 As schematically shown in FIG. 1 , the tank 3 has a first tank portion 11 defined by a first vertical distance range from the bottom 13 of the tank 3 and a second tank portion 15 defined by a second vertical distance range from the bottom 13 of the tank 3. The first range and the second range are non-overlapping with each other.

[0037] When the tank device 1 is in use, a flow of material components is received through the inlet 5. The material components include at least: a liquid first substance 17 having a first density and a liquid second substance 19 having a second density lower than the first density. The first substance 17 may be, for example, water, and the second substance 19 may be, for example, oil. In the tank 3, the first substance 17 and the second substance 19 may phase separate to a degree of separation which may, for example, depend on the settling time since the material components were last input through the inlet 5. For example, there may be an emulsion layer 21 of unknown thickness between a bottom layer of pure first substance 17 and a top layer of pure second substance 19.

[0038] Due to the potentially time-varying and generally unknown degree of separation between the first substance 17 and the second substance 19, it may be desirable to estimate the composition of the substances in the first tank portion 11, for example to determine when and how to allow output through the outlet 9. For example, it may be desirable to control the timing and / or flow rate of output through the outlet 9 based on an estimate of the composition of the substances in the first tank portion 11. In the illustrative case where the first substance 17 is water and the second substance 19 is oil, it may be desirable to output only pure water or nearly pure water through the outlet 9, rather than a water-oil emulsion.

[0039] In an example embodiment of the invention, the first radar metrology system 7 may be used to provide a desired estimate of the composition of the substance in the first tank portion 11 .

[0040] Reference Figure 1 , the radar metrology system 7 includes a first transmission line probe 23 having a first probe end 25 and an impedance discontinuity 27 spaced apart from the first probe end 25 along the first transmission line probe 23. The first transmission line probe 23 is arranged inside the tank 3 such that a portion 29 of the first transmission line probe 23 extending from the first probe end 25 to the impedance discontinuity 27 is exclusively located in the first tank portion 11.

[0041] FIG. 2A to FIG. 2B The schematic diagram shows the Figure 1 An example configuration of a first radar metrology system 7 in a tank device in which: Figure 2B Schematically shows Figure 2A The first transmission line probe 23 is along Figure 2A A cross section of a section taken along line AA'.

[0042] First refer to Figure 2A The first radar metrology system 7 includes the above-mentioned first transmission line probe 23, a first transceiver 31 and a first processing circuit system (μP) 33. The first probe end 25 of the first transmission line probe 23 is coupled to the first transceiver 31, and the first transceiver 31 is configured to generate an electromagnetic transmission signal S Tand sends it to the first transmission line probe 23. The first transmission line probe 23 is configured to send the signal S T The transmission signal S is guided from the first probe tip 25 to the impedance discontinuity 27 and returned to the first transceiver (Tx / Rx) 31. T The electromagnetic reflection signal S generated by the reflection at the impedance discontinuity 27 R .

[0043] By using techniques known per se to a person skilled in the art, the transmitted signal S is evaluated. T With the reflected signal S R The first processing circuit system 33 can be configured to estimate the distance between the first probe tip 25 and the impedance discontinuity 27, the first probe tip 25 being a reference position at the interface between the first transceiver 31 and the transmission line probe 23. T (and the reflected signal S R ) The estimated distance of the flight time along the portion 29 of the first transmission line probe 23 is compared with the corresponding known first distance between the first probe tip 25 and the impedance discontinuity, and the transmitted signal S can be estimated. T (and the reflected signal S R ) propagation speed. Based on the estimated propagation speed, another signal propagation characteristic such as the (average) dielectric constant can be estimated, and / or information about the signal S transmitted through it can be derived. T (and the reflected signal S R ) has been propagated. The impedance discontinuity 27 may be, for example, Figure 2A The reference impedance may be provided by a second probe tip schematically indicated in , or by a reference impedance discontinuity spaced apart from the second probe tip.

[0044] exist FIG. 2A to FIG. 2B In the example configuration shown, the first transmission line probe 23 includes a probe conductor 35 coupled to the first transceiver 31 and a dielectric layer 37 surrounding the probe conductor 35. The dielectric layer 37 may be made of PTFE, for example, and may have a thickness in the range of 1 mm to 10 mm.

[0045] Figure 3 A second example of a tank device 1 according to an embodiment of the present invention is schematically shown, which tank device is similar to the one described above with reference to FIG. Figure 1 The tank arrangement described differs mainly in that it comprises a second radar metering system 39 arranged at the tank 3. Figure 3 The second radar metrology system 39 includes a second transmission line probe 41 having a first probe end 43. Figure 3In the exemplary configuration schematically shown in FIG. 4 , the second transmission line probe 41 additionally has a reference reflector 45 for providing impedance discontinuity. Figure 3 As shown, in this example configuration, the second transmission line probe 41 is arranged inside the tank 3 so that a portion 47 of the second transmission line probe 41 extending from the first probe end 43 to the impedance discontinuity, here provided by the reference reflector 45 , is located exclusively in the second tank portion 15 .

[0046] Figure 4 The schematic diagram shows the Figure 3 1 is an example configuration of a second radar metrology system 39 in a tank device 1. The second radar metrology system 39 includes the above-mentioned second transmission line probe 41, a second transceiver 49, and a second processing circuit system 51. The first probe end 43 of the second transmission line probe 41 is coupled to the second transceiver 49, which is configured to generate an electromagnetic transmission signal S T The second transmission line probe 41 is configured to transmit the transmission signal S from the first probe end 43 to the second transmission line probe 41. T The material components in the tank are directed toward the tank and enter the tank, and are returned to the second transceiver 49 by the transmission signal S T The electromagnetic reflection signal S generated by the reflection at at least one impedance discontinuity encountered thereby R One such impedance discontinuity may be provided by the level of the surface 53 of the material composition, and another such impedance discontinuity may be provided by the reference reflector 45 .

[0047] By using techniques known per se to a person skilled in the art, the transmitted signal S is evaluated. T With the reflected signal S R The second processing circuit system 51 can be configured to estimate the distance between the first probe end 43 and the surface 53 of the product component, which is a reference position at the interface between the second transceiver 49 and the second transmission line probe 41. The second processing circuit system 51 can additionally be configured to estimate the distance between the surface 53 of the surface of the product component and the impedance discontinuity provided by the reference reflector 45. By converting the transmitted signal S T (and the reflected signal S R The distance between the surface 53 and the reference reflector 45 estimated along the time of flight of the portion 47 of the second transmission line probe 41 is compared with the corresponding known second distance between the first probe tip 43 and the impedance discontinuity provided by the reference reflector 45, and the transmitted signal S can be estimated. T (and the reflected signal S R) propagation speed. Based on the estimated propagation speed, another signal propagation characteristic such as the (average) dielectric constant can be estimated, and / or information about the transmission signal S transmitted through it can be derived. T (and the reflected signal S R ) of the material composition. It should be noted that the impedance discontinuity may be defined by other means than the reference reflector 45 provided here as an illustration. For example, the impedance discontinuity may be provided by the second probe tip.

[0048] Figure 5 A third example of a tank device 1 in the form of a phase separator arrangement according to an embodiment of the invention is schematically shown. The tank 3 is elongated in a first, substantially horizontal direction 55 and extends between a first tank end 57 and a second tank end 59 in the first direction 55. As can be seen in FIG. Figure 5 As seen in FIG. 4 , the tank 3 has an inlet 5 , a first outlet 9 , a second outlet 61 , an optional third outlet 63 and an overflow weir 65 .

[0049] The inlet 5 is arranged adjacent to the first tank end 57, the overflow weir 65 is arranged at the weir position 67, spaced apart from the inlet 5 in the first direction 55, the first outlet 9 is arranged horizontally between the inlet 5 and the weir position 67 at the bottom of the tank 3, the second outlet 61 is arranged horizontally between the weir position 67 and the second tank end 59 at the bottom of the tank 3, the optional third outlet 63 is arranged at the top of the tank 3, the first radar metering system 7 is arranged at the first metering position 69 between the inlet 5 and the weir position 67, and the optional second radar metering system 39 is arranged at the second metering position 71 between the inlet 5 and the weir position 67. The first metering position 69 and the second metering position 71 may advantageously be arranged close to each other in the first direction 55.

[0050] when Figure 5 When the tank device 1 in the embodiment is used for phase separation, a flow of material components is received through the inlet 5. The material components include at least a liquid first substance 17 having a first density and a liquid second substance 19 having a second density lower than the first density. The first substance 17 may be, for example, water and the second substance 19 may be, for example, oil. When entering the tank 3 through the inlet, the material components may be in the form of an emulsion 21 of the first substance 17 and the second substance 19. When advancing through the tank in a horizontal first direction 55 at an appropriate rate, the emulsion 21 separates at the bottom of the tank 3 into a pure first substance 17, and a pure second substance 19 floats on top of the first substance 17. Between the thus separated layers of the first substance 17 and the second substance 19, an emulsion boundary layer may remain. The first substance 17 is output through the first outlet 9, and the second substance 19 is output through the second outlet 61 after flowing over the overflow weir 65. The third gaseous substance 73 may be output through the third outlet 63.

[0051] As further described above, the first radar metrology system 7 can be used to estimate signal propagation characteristics such as the dielectric constant of a material component within a first volume surrounding the above-defined portion 29 of the first transmission line probe 23, and the second radar metrology system 39 can be used to determine the level of a second material 19 such as oil in the tank 3 and / or a signal propagation characteristic such as the dielectric constant of a material component within a second volume surrounding the above-defined portion 47 of the second transmission line probe 41. One or more of these devices can be used to control the flow rate of the material component at the inlet 5, for example. Figure 5 The operation of phase separation provided in the tank device 1 in the embodiment of the present invention. If the estimated signal propagation characteristics in the first level range around the portion 29 of the first transmission line probe 23 indicate that a mixture of the first substance 17 and the second substance 19 is present at the bottom of the tank 3 at the first outlet 9, the first outlet 9 can be closed and the flow of the substance components at the inlet 5 can be stopped to ensure that the second substance 19, such as oil, is not discarded to the environment through the first outlet 9.

[0052] Now refer to Figure 6 The flowchart in the figure describes a method according to an example of the present invention. As indicated in the text, reference may also be made to other figures.

[0053] Reference Figure 6 , providing 101 a first transmission line probe 23 having a first probe end 25 and an impedance discontinuity 27 spaced apart from the first probe end by a known first distance along the first transmission line probe, the first transmission line probe 23 being arranged inside the tank 3 such that a portion 29 of the first transmission line probe 23 extending from the first probe end 25 to the impedance discontinuity 27 is exclusively located in the relatively low first tank portion 11.

[0054] The electromagnetic transmission signal S is generated and transmitted 102 by the first transceiver 31 T The transmission signal S may be provided, for example, in the form of a pulse train and / or as a continuous signal with a time-varying frequency. T , which itself is well known to a person skilled in the art.

[0055] The signal S will be sent T A first probe tip 25 is provided 103 to the first transmission line probe 23 .

[0056] The first transceiver 31 receives 104 the transmission signal S from the first transmission line probe 23. T The electromagnetic reflection signal S generated by the reflection at the impedance discontinuity 27 of the first transmission line probe 23 R .

[0057] Thereafter, based on the transmitted signal S T With the reflected signal S RBased on the timing relationship between and the known length of the portion 29 of the first transmission line probe 23, the signal propagation characteristics (such as the (average) dielectric constant) of the material components within the first volume surrounding the portion 29 of the first transmission line probe are estimated 105 by the first processing circuit system 33.

[0058] Figure 7 7 is an exemplary echo curve 73 obtained using the first radar measurement system 7. For example, the echo curve can be obtained using a time expansion technique that is well known in the field of level measurement using pulsed electromagnetic signals, which shows the relationship between the flight time t of each echo and the amplitude A of the echo signal. Figure 7 As can be seen from the schematic echo curve 73 in FIG. 7 , there is a first echo peak 75 and a second echo peak 77. The first echo peak 75 is generated by the transmitted signal S T A reflection is produced at the impedance discontinuity provided by the connection between the first transceiver 31 and the first probe tip 25 of the first transmission line probe 23. This echo peak 75 is used as a reference position indicating the position of the first probe tip 25 along the first transmission line probe 23 and is sometimes referred to as a reference pulse. Figure 7 In the exemplary echo curve 73 in FIG. 1 , the second echo peak 77 is generated by the transmitted signal S T Reflections occur at an impedance discontinuity defining the extension of the portion 29 of the first transmission line probe 23 along the first transmission line probe 23. As mentioned further above, the impedance discontinuity may be provided by the second probe tip of the first transmission line probe 23, for example.

[0059] Therefore, the "electrical distance" between the first probe tip 25 and the impedance discontinuity 27 can be determined based on the difference Δt1 in the flight times of the first echo peak 75 and the second echo peak 77, respectively. The electrical distance thus determined is a function of the flight time difference Δt1 and the propagation speed of the transmitted signal in the first volume of the material composition surrounding the portion 29 of the first transmission line probe 23. Therefore, the propagation speed can be estimated based on the electrical distance (or flight time difference) and the known length of the portion 29 of the first transmission line probe 23 (the physical distance between the first probe tip 25 and the impedance discontinuity 27). Based on the propagation speed, the signal propagation characteristics (such as the average relative dielectric constant) in the first volume of the material composition surrounding the portion 29 of the first transmission line probe 23 can be estimated. Based on the signal propagation characteristics, conclusions about the material composition in the first tank portion 11 can be drawn. For example, as in Figure 5In the case of a phase separation tank device 1 in FIG. 1 , it can be determined whether the portion 29 of the first transmission line probe 23 is surrounded by pure water or an oil-water emulsion, and if so, the emulsion ratio. In applications where the first substance is water or another substance with a very high dielectric constant, it may be beneficial to provide the first transmission line probe 23 with a thin coating of a dielectric material such as PTFE.

[0060] As previously mentioned, a tank installation according to an embodiment of the present invention may include a second radar gauging system. Figure 3 An example of such a tank arrangement is schematically shown in Figure 5 Another example is schematically shown in FIG. When performed using such a tank device 1 , the method according to an embodiment of the present invention may optionally additionally include: generating and sending 106 an electromagnetic transmission signal S by the second transceiver 49 T ; will send signal S T Provide 107 to the first probe end 43 of the second transmission line probe 41; and receive 108 the transmitted signal S by the second transceiver 49. T The electromagnetic reflection signal S generated by the reflection at one or more impedance discontinuities encountered thereby R .

[0061] Thereafter, the second processing circuit system 51 processes the transmitted signal S T With the reflected signal S R The timing relationship between the two and the known length of the portion 47 of the second transmission line probe 41 are used to estimate 109 the level of the surface 53 of the material component in the tank 3 (refer to Figure 3 ) and / or signal propagation properties (e.g. (average) dielectric constant) of material components within the second volume surrounding portion 47 of the second transmission line probe 41.

[0062] Figure 8 79 is an exemplary echo curve 79 obtained using the second radar measurement system 39. For example, the echo curve can be obtained using a time expansion technique that is well known in the field of level measurement using pulsed electromagnetic signals, and shows the relationship between the flight time t of each echo and the amplitude A of the echo signal. Figure 8 As can be seen from the schematic echo curve 79 in FIG. 8 , there are a first echo peak 81, a second echo peak 83, a third echo peak 85, a fourth echo peak 87 and a fifth echo peak 89. The first echo peak 81 is generated by the transmitted signal S T A reflection is produced at the impedance discontinuity provided by the connection between the second transceiver 49 and the first probe end 43 of the second transmission line probe 41. This echo peak 81 is used as a reference position indicating the position of the first probe end 43 along the second transmission line probe 41 and is sometimes referred to as a reference pulse. Figure 8 In the exemplary echo curve 79 in FIG. 1 , the second echo peak 83 is generated by the transmitted signal S T 4. The third echo peak 85 is produced by reflection at the surface 53 of the material component, the fourth echo peak 87 is produced by reflection at an exemplary material interface along the second transmission line probe 41, and the fifth echo peak 89 is produced by reflection at the second probe end of the second transmission line probe 41. As mentioned earlier, the reference reflector 45 provides an impedance discontinuity that defines the extension of the portion 47 of the second transmission line probe 41 along the second transmission line probe 41.

[0063] Therefore, the "electrical distance" between the surface 53 of the material component and the impedance discontinuity provided by the reference reflector 45 can be determined based on the difference Δt2 in the flight time of the second echo peak 83 and the third echo peak 85, respectively. The electrical distance thus determined is a function of the flight time difference Δt2 and the propagation speed of the transmitted signal in the second volume of the material component surrounding the portion 47 of the second transmission line probe 41. Therefore, the propagation speed can be estimated based on the electrical distance (or flight time difference) and the known length of the portion 47 of the second transmission line probe 41 (the physical distance between the first probe end 43 and the impedance discontinuity provided by the reference reflector 45). This known distance is equivalent to the position of the reference reflector 45 along the second transmission line probe 41. Based on the propagation speed, the signal propagation characteristics (average relative dielectric constant) in the second volume of the material component surrounding the portion 47 of the second transmission line probe 41 can be estimated. Based on the signal propagation characteristics, conclusions about the material component in the second tank portion 15 can be drawn. For example, as in Figure 5 In the case of a phase separation tank device 1 in FIG. 1 , it can be determined whether the portion 47 of the second transmission line probe 41 is (partially) surrounded by pure oil or by an oil-water emulsion, and if so, the emulsion ratio. This can be used to further improve the control of the operation of the tank device 1.

[0064] Those skilled in the art realize that the present invention is by no means limited to the preferred embodiments described above. For example, other probe arrangements are also feasible.

[0065] "Matter" is generally not limited to any particular phase of matter, and thus may include solids, liquids, and gases. Some examples of matter may be various petroleum products, water, sludge, or sand, among others.

[0066] A "transceiver" may be one functional unit capable of sending and receiving electromagnetic signals, or may be a system comprising separate transmitter and receiver units.

[0067] A tank may be any container or tank capable of containing a product and may be metallic or partially or completely non-metallic, open, semi-open or closed.

Claims

1. A tank device comprising: a tank having a first tank portion defined by a first vertical distance range from a bottom of the tank and a second tank portion defined by a second vertical distance range from the bottom of the tank, the second vertical distance range only containing distances greater than all distances in the first vertical distance range; an inlet for receiving a material component, the material component comprising at least a liquid first material having a first density and a liquid second material having a second density lower than the first density; At least a first radar metrology system, said at least first radar metrology system being arranged at said tank, said first radar metrology system comprising: A first transceiver for generating, sending and receiving electromagnetic signals; a first transmission line probe having a first probe end coupled to the first transceiver and an impedance discontinuity spaced a known first distance along the first transmission line probe from the first probe end, the first transmission line probe being arranged inside the tank so that a portion of the first transmission line probe extending from the first probe end to the impedance discontinuity is exclusively located in the first tank portion, the first transmission line probe being configured to direct an electromagnetic transmit signal provided by the first transceiver from the first probe end to the impedance discontinuity, and the first transmission line probe being configured to return an electromagnetic reflection signal to the first transceiver, the electromagnetic reflection signal being generated by reflection of the transmit signal at the impedance discontinuity; and A first processing circuit system is coupled to the first transceiver and is configured to estimate a signal propagation characteristic of the material component within a first volume surrounding the portion of the first transmission line probe based on a timing relationship between the transmitted signal and the reflected signal and based on the known first distance.

2. The tank arrangement of claim 1, the inlet being arranged in the second tank part.

3. The tank device according to claim 1 or 2, comprising: An outlet is arranged in the first tank part for outputting the first substance separated from the substance component.

4. The tank device of claim 1 , wherein the first processing circuit system of the first radar metrology system is configured to determine a metric indicative of a proportion of the first substance in the material composition within the first volume surrounding the portion of the first transmission line probe based on the estimated signal propagation characteristics, the known signal propagation characteristics of the first substance, and the known signal propagation characteristics of the second substance. 5 . The tank device according to claim 1 , wherein the impedance discontinuity of the first transmission line probe of the first radar gauging system is located at a higher vertical level than an end of the first probe. 6 . The tank device according to claim 1 , wherein the impedance discontinuity of the first transmission line probe of the first radar gauging system is constituted by a second probe end of the first transmission line probe.

7. The tank device according to claim 1 or 2, wherein the first transmission line probe of the first radar metrology system comprises: a probe conductor coupled to the transceiver; as well as A dielectric layer at least partially surrounds the probe conductor.

8. The tank device of claim 7, the dielectric layer completely surrounding the probe conductor in the probe portion.

9. The tank device according to claim 1 or 2, The tank is elongated in a first, substantially horizontal direction and extends in the first direction between a first tank end and a second tank end; The inlet is adjacent to the first tank end; the tank comprising an overflow weir disposed at a weir location between the inlet and the second tank end; The tank comprises a first outlet arranged horizontally at the bottom of the tank between the inlet and the weir location for outputting a first substance separated from the substance component; The tank comprises a second outlet arranged horizontally at the bottom of the tank between the weir location and the second tank end for outputting a second substance separated from the substance component; and The first radar metering system is arranged to meter the material component at a first metering location between the inlet and the weir location.

10. The tank device according to claim 9, wherein: The first radar metering system is arranged horizontally between the first outlet and the weir location.

11. The tank device according to claim 1 or 2, comprising: A second radar metrology system arranged at the tank, the second radar metrology system comprising: a second transceiver, the second transceiver being configured to generate, send and receive electromagnetic signals; a second transmission line probe having a first probe end coupled to the second transceiver, the second transmission line probe being configured to direct an electromagnetic transmission signal from the second transceiver from the first probe end toward the substance component in the tank, and the second transmission line probe being configured to return an electromagnetic reflection signal generated by reflection of the transmission signal at a surface of the substance component to the second transceiver; and Second processing circuitry is coupled to the second transceiver and is configured to estimate a level of a surface of the material composition based on a timing relationship between the transmitted signal and the reflected signal.

12. The tank device according to claim 11, the second transmission line probe having an impedance discontinuity spaced a known second distance along the second transmission line probe from the first probe end, the second transmission line probe being arranged inside the tank such that a portion of the second transmission line probe extending from the first probe end to the impedance discontinuity is located exclusively in the second tank portion; and The second processing circuitry is configured to estimate a signal propagation characteristic of the material component within a second volume surrounding the portion of the second transmission line probe based on a timing relationship between the transmit signal and the reflected signal and based on the known second distance.

13. A method of estimating signal propagation characteristics of a material composition in a first tank portion, the first tank portion being defined by a first vertical distance range from a bottom of the tank, the first tank portion being below a second tank portion defined by a second vertical distance range from the bottom of the tank, the method comprising: providing a first transmission line probe having a first probe end and an impedance discontinuity spaced a known first distance along the first transmission line probe from the first probe end, the first transmission line probe being disposed within the interior of the tank such that a portion of the first transmission line probe extending from the first probe end to the impedance discontinuity is located exclusively within the first tank portion; generating and transmitting an electromagnetic transmit signal by a first transceiver; providing the transmit signal to the first probe end of the first transmission line probe; receiving, by the first transceiver, from the first transmission line probe, an electromagnetic reflection signal generated by reflection of the transmission signal at the impedance discontinuity of the first transmission line probe; as well as Signal propagation characteristics of the material constituent within a first volume surrounding the portion of the first transmission line probe are estimated by first processing circuitry coupled to the first transceiver based on a timing relationship between the transmitted signal and the reflected signal and based on the known first distance.

14. The method according to claim 13, comprising: A metric indicative of a proportion of the first substance in the material composition within the first volume surrounding the portion of the first transmission line probe is determined by the first processing circuitry based on the estimated signal propagation characteristics, the known signal propagation characteristics of the first substance, and the known signal propagation characteristics of the second substance.

15. The method according to claim 13 or 14, comprising: providing a second transmission line probe having a first probe end and an impedance discontinuity spaced a known second distance along the second transmission line probe from the first probe end, the second transmission line probe being disposed within the interior of the tank such that a portion of the second transmission line probe extending from the first probe end to the impedance discontinuity is located exclusively within the second tank portion; generating and transmitting an electromagnetic transmit signal by a second transceiver; providing the transmit signal to the first probe end of the second transmission line probe; receiving, by the second transceiver, from the second transmission line probe, an electromagnetic reflection signal generated by reflection of the transmission signal at the impedance discontinuity of the second transmission line probe; as well as Signal propagation characteristics of the material constituent within a first volume surrounding the portion of the first transmission line probe are estimated by first processing circuitry coupled to the first transceiver based on a timing relationship between the transmitted signal and the reflected signal and based on the known second distance.

Images