A shipborne waveguide radar liquid level measuring device and measuring method

Abstract

The application discloses a kind of ship waveguide radar liquid level measuring device and measuring method, industrial measurement technical field, the measuring cylinder of known height, it is vertically arranged in parallel in the outside of the container to be measured, and the measuring cylinder is communicated with the container to be measured by communicating pipe;The waveguide rod is inserted from the top wall of the measuring cylinder, and the radar signal transceiver device is arranged at the top end of the waveguide rod;Reference collar is sleeved on the waveguide rod, and the reference collar is set between the top wall of the measuring cylinder Height;The radar signal transceiver device calculates the reference liquid level height according to the height of the measuring cylinder, the set height and the time value of radar wave reaching reference collar and liquid level respectively.The measuring device and the measuring method of the application install measuring cylinder in the side of the container to be measured, which is convenient for cleaning and maintenance, and through reference optimization calculation, density difference compensation and inclination compensation, more accurate liquid level data is measured.

Description

Technical Field

[0001] This application relates to the field of industrial measurement technology, specifically to a device and method for measuring liquid level using a marine guided wave radar. Background Technology

[0002] Currently, guided wave radar liquid level measurement technology is one of the commonly used liquid level measurement technologies in automated production. It has the advantages of high precision and high anti-interference capability, and can be applied to high-precision liquid level measurement in complex environments such as corrosion, high temperature and high pressure, and dust. It is widely used in fields such as civilian nuclear power, thermal power, petrochemicals and metallurgy.

[0003] Guided wave radar level measurement technology is mainly based on the time-domain reflection principle of electromagnetic waves. The principle of guided wave radar level measurement is as follows: Figure 1 As shown, radar transceiver 1 emits radar waves, which propagate along waveguide 2, forming a fixed echo at the starting point of waveguide 2. When the radar waves encounter the surface of the working fluid 3, a liquid level echo is formed because the dielectric constant of the working fluid 3 is greater than that of the previous conductive medium (such as air). Radar transceiver 1 detects the fixed echo and the liquid level echo, and calculates the time difference between them. Based on the transmission speed of the radar waves and the dielectric constant of the steam 5, the liquid level height of the working fluid 3 can be calculated.

[0004] However, in practical applications, guided wave radar level measurement technology faces significant challenges in accurately and reliably measuring the liquid level in high-temperature, high-pressure sealed containers such as steam generators and nuclear reactor pressurizers under marine conditions. The main reasons are as follows:

[0005] First, in high-temperature, high-pressure, and highly saturated steam environments, the dielectric constant of steam changes with temperature and pressure. This change in dielectric constant affects the propagation speed of radar waves, thus causing measurement errors in guided wave radar. Second, the sloshing of the liquid surface caused by the ship's movement means that the measured liquid level does not equal the actual liquid level. Third, waveguides installed in high-temperature, high-pressure, sealed containers are difficult to clean and maintain; over time, a large amount of deposits will accumulate on the surface of the waveguide, further affecting the propagation speed of radar waves. Summary of the Invention

[0006] In view of the deficiencies in the existing technology, the purpose of this application is to provide a liquid level measuring device and method for marine guided wave radar. The measuring cylinder is installed on the side of the container being measured, which facilitates cleaning and maintenance. Through reference optimization calculation, density difference compensation and tilt angle compensation, higher accuracy liquid level data can be measured.

[0007] To achieve the above objectives, the technical solution adopted is: a marine guided wave radar liquid level measuring device, which, in conjunction with a radar signal transceiver and a waveguide rod, measures the liquid level height in a container to be measured. A measuring cylinder of known height is vertically arranged side by side on the outside of the container to be measured, and the measuring cylinder is connected to the container to be measured through a connecting pipe; the waveguide rod is inserted from the top wall of the measuring cylinder, and the radar signal transceiver is located at the top of the waveguide rod;

[0008] A reference collar is fitted onto the waveguide rod and located between the liquid surface and the top wall of the measuring cylinder, with a set height between the reference collar and the top wall of the measuring cylinder.

[0009] The radar signal transceiver device calculates the reference liquid level height in the container to be measured based on the height of the measuring cylinder, the set height, and the time values ​​when the radar wave reaches the reference collar and the liquid surface, respectively.

[0010] Based on the above technical solution, the measuring device also includes several temperature sensors disposed below the liquid surface, one of which is disposed inside the container to be measured, and the remaining temperature sensors are disposed at different depths inside the measuring cylinder; all temperature sensors are connected to a radar signal transceiver device, which is also used to compensate for the density difference in the liquid level height based on the temperature data measured by the temperature sensors.

[0011] Based on the above technical solution, the measuring device also includes two tilt sensors respectively installed in the transverse and longitudinal directions of the hull, and both tilt sensors are connected to a radar signal transceiver device; the radar signal transceiver device is also used to perform tilt compensation on the liquid level height based on the transverse and longitudinal tilt angles measured by the tilt sensors.

[0012] This application discloses a measurement method based on the above-mentioned marine guided wave radar liquid level measuring device, comprising the following steps:

[0013] The radar signal transceiver device measures two time values: the time value of the radar wave arriving at the reference collar and the liquid surface of the working fluid to be measured.

[0014] The radar signal transceiver device calculates the reference liquid level height of the working fluid to be measured based on the height of the measuring cylinder, the set height, and two time values.

[0015] Based on the above technical solution, the waveguide rod axis is coaxial with the axis of the measuring cylinder, and the measuring cylinder is connected to the container under test through two connecting pipes, the two ends of each connecting pipe being perpendicular to the side wall of the measuring cylinder and the side wall of the container under test; the reference liquid level height H in the container under test is... ε Calculation method:

[0016]

[0017] Where h is the known height of the measuring cylinder, l0 is the set height between the reference collar and the top wall of the measuring cylinder, t0 is the time value of the radar wave reaching the reference collar, and t is the time value of the radar wave reaching the surface of the working fluid to be measured.

[0018] Based on the above technical solution, the measuring device also includes three temperature sensors disposed below the liquid surface, one of which is disposed inside the container to be measured, and two of which are disposed at different depths inside the measuring cylinder; all three temperature sensors are connected to a radar signal transceiver device, which is also used to compensate for the density difference of the reference liquid level height based on the temperature data measured by the temperature sensors and the installation dimensions of the connecting pipe relative to the container to be measured and the measuring cylinder.

[0019] Based on the above technical solution, the liquid level height H after density difference compensation ερ Calculation method:

[0020]

[0021]

[0022] Where, ρ v The density of the working fluid inside the test container is obtained by looking up a table using the temperature of the working fluid inside the test container. Let ρ be the average density of the working fluid inside the measuring cylinder, b be the known height from the lower connecting pipe to the bottom of the measuring cylinder, h0 be the known height from the lower connecting pipe to the bottom of the container being measured, x1 be the known height from one temperature sensor inside the measuring cylinder to the lower connecting pipe, x2 be the known height from another temperature sensor inside the measuring cylinder to the lower connecting pipe, and ρ be the known height from the other temperature sensor inside the measuring cylinder to the lower connecting pipe. x1 ρ x2 The corresponding density is obtained by referring to a table based on the temperature measured by two temperature sensors inside the measuring cylinder, which are used by the radar signal transceiver device.

[0023] Based on the above technical solution, the liquid level height H after tilt angle compensation ερθ for

[0024] H ερθ =H ερ -dcosφtanθ;

[0025]

[0026] Where θ is the angle between the axis of the container under test and the vertical line, α is the longitudinal heel angle of the hull measured by the tilt sensor, β is the transverse heel angle of the hull measured by the tilt sensor, φ is the angle between the line connecting the top view center of the measuring cylinder and the container under test and the navigation vertical line, and d is the distance between the axis of the measuring cylinder and the axis of the container under test.

[0027] Based on the above technical solution, the liquid level height H after tilt angle compensation ερθ The measurement accuracy can reach ±1mm.

[0028] Based on the above technical solution, the liquid level height H after tilt angle compensation ερθ It outputs a current signal of 4-20mA.

[0029] The beneficial effects of the technical solution provided in this application include:

[0030] The measuring device and method of this application indirectly measure the liquid level height in the container under test through a measuring cylinder. The measuring cylinder is set on the outside of the container under test, which facilitates timely disassembly of the waveguide for cleaning and maintenance, so that the liquid level measurement is not affected by the deposits on the waveguide.

[0031] Compared to existing guided wave radar liquid level measurement technology, which calculates liquid level height by combining the vacuum propagation speed of radar waves with the dielectric constant of the working fluid vapor, the measuring device of this application completely avoids the dielectric constant and bypasses the problem that the dielectric constant of vapor changes with temperature and pressure, thus enabling the measurement of liquid level data with higher accuracy.

[0032] Furthermore, it can also compensate for density difference and tilt angle in liquid level height, eliminating errors caused by indirect measurement. At the same time, it facilitates the cleaning and maintenance of the waveguide rod and improves the accuracy of liquid level height measurement. It also solves the problem of inaccurate liquid level measurement due to ship swaying in the existing technology. It improves the adaptability of measurement, is not affected by dielectric constant, and is not affected by ship swaying, which can greatly improve the accuracy of liquid level height measurement. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of existing guided wave radar liquid level measurement technology.

[0035] Figure 2 A schematic diagram showing the measuring cylinder and reference collar structure, as well as the relevant dimensions for calculating the reference liquid level height, provided in the embodiments of this application.

[0036] Figure 3 A schematic diagram showing the structure of the measuring device and the relevant dimensions of the density difference compensation stage provided in the embodiments of this application;

[0037] Figure 4A top view of the measuring cylinder and the container under test provided in the embodiments of this application during navigation;

[0038] Figure 5 A schematic diagram showing the structure of the measuring device and the relevant dimensions of the tilt compensation stage provided in the embodiments of this application;

[0039] Figure 6 A main flowchart of the measurement method provided in the embodiments of this application;

[0040] Reference numerals in the attached figures: 1. Radar signal transceiver; 2. Waveguide rod; 3. Working fluid to be measured; 4. Container to be measured; 5. Steam; 10. Measuring cylinder; 11. Connecting pipe; 12. Reference collar. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] like Figures 1 to 6 As shown, this application discloses an embodiment of a marine guided wave radar liquid level measuring device, which, in conjunction with a radar signal transceiver 1 and a waveguide rod 2, measures the liquid level height of the working medium 3 in the container 4 under test. The measuring device of this application can more accurately measure the liquid level height of the working medium 3 under test.

[0043] The measuring device includes a measuring cylinder 10 and a reference collar 12. The height of the measuring cylinder 10 is known. The measuring cylinder 10 is vertically arranged side-by-side outside the container 4 to be measured, and the axis of the measuring cylinder 10 is parallel to the axis of the container 4 to be measured. The measuring cylinder 10 is connected to the container to be measured through a connecting pipe 11. The waveguide rod 2 is inserted from the top wall of the measuring cylinder 10, and the radar signal transceiver 1 is located at the top of the waveguide rod 2. The measuring cylinder 10 of this application is arranged side-by-side outside the container 4 to facilitate timely cleaning and maintenance of the radar signal transceiver 1 and the waveguide rod 2, so that the liquid level measurement is not affected by the deposits on the waveguide rod 2.

[0044] The reference collar 12 is fitted on the waveguide rod 2 as a reference. The reference collar 12 is located between the liquid surface and the top wall of the measuring cylinder 10 to provide a reference for directly measuring the transmission speed of radar waves in steam. The distance between the reference collar 12 and the top wall of the measuring cylinder 10 is the set height.

[0045] The internal program of the radar signal transceiver 1 has been upgraded and improved, and it no longer only has the function of measurement, but also the function of calculation and compensation. The radar signal transceiver 1 calculates the reference liquid level height in the container to be measured 4 based on the height of the measuring cylinder 10, the set height between the reference collar 12 and the top wall of the measuring cylinder 10, and the time values ​​of the radar wave reaching the reference collar 12 and the liquid surface, respectively.

[0046] The marine guided wave radar liquid level measuring device of this application indirectly measures the liquid level height in the container 4 under test through the measuring cylinder 10. The measuring cylinder 10 is set on the outside of the container 4 under test, which facilitates timely disassembly of the waveguide rod 2 for cleaning and maintenance, so that the liquid level measurement is not affected by the attached substances on the waveguide rod 2.

[0047] Meanwhile, the measuring device provides a reference reference with a known set height by setting a reference collar 12. Based on the time value of the radar wave reaching the reference reference, the propagation speed of the radar wave in the steam is directly calculated, and then the reference liquid level height is calculated based on the propagation speed. Compared with the existing guided wave radar liquid level measurement technology, which calculates the liquid level height by combining the vacuum propagation speed of the radar wave with the dielectric constant of the working medium 3, the measuring device of this application completely avoids the dielectric constant and completely bypasses the problem that the dielectric constant of steam changes with temperature and pressure, and can measure liquid level data with higher accuracy.

[0048] Furthermore, since the measuring cylinder 10 indirectly measures the liquid level in the container 4 to be tested, even though the two are connected by a connecting pipe, the uneven temperature distribution will still result in uneven density distribution of the working fluid in the measuring cylinder 10 and the container 4 to be tested.

[0049] To address the new problems arising from this indirect measurement, the measuring device of this application eliminates the error between the liquid level in the measuring cylinder 10 and the liquid level in the container 4 to be measured by density difference compensation, thereby improving the measurement accuracy.

[0050] Specifically, the measuring device also includes several temperature sensors, all of which are positioned below the liquid surface. One temperature sensor is located inside the container 4 to be tested. Since the internal space of container 4 is relatively large, the temperature and density distribution is relatively uniform; therefore, only one temperature sensor is needed. The remaining temperature sensors are located at different depths inside the measuring cylinder 10. Because the measuring cylinder 10 is relatively long and narrow, it is prone to uneven density distribution; therefore, several temperature sensors are used, specifically at least two.

[0051] All temperature sensors are connected to radar signal transceiver 1, which is also used to compensate for density difference in liquid level height based on the temperature data measured by the temperature sensors.

[0052] The measuring device of this application, after compensating for the density difference in the liquid level height, eliminates the error caused by indirect measurement, while also facilitating the cleaning and maintenance of the waveguide rod and improving the accuracy of liquid level height measurement.

[0053] In one embodiment, based on the above technical solution, the measuring device further includes two tilt sensors, which are respectively positioned laterally and longitudinally on the hull to measure the heel and pitch angles during hull navigation. Both tilt sensors are connected to a radar signal transceiver 1, which is also used to perform tilt angle compensation on the liquid level height based on the heel and pitch angles measured by the tilt sensors.

[0054] The measuring device of this application compensates for the tilt angle of the liquid level height, thus solving the problem of inaccurate liquid level measurement due to ship swaying in the prior art.

[0055] This application also discloses a measurement method based on the above-mentioned marine guided wave radar liquid level measuring device, comprising the following steps:

[0056] The radar signal transceiver 1 measures two time values: the time it takes for the radar wave to reach the reference collar 12 and the time it takes for the working medium 3 to reach the surface of the reference medium. Specifically, during the downward transmission of the radar wave, there are three main echoes: the first echo is the fixed echo from the flange, the second echo is the fixed echo from the reference collar 12, and the third echo is the echo from the surface of the working medium. Half of the time difference between the first and second echoes is the time it takes for the radar wave to reach the reference collar 12; half of the time difference between the first and third echoes is the time it takes for the radar wave to reach the surface of the working medium 3.

[0057] The radar signal transceiver 1 calculates the reference liquid level height of the working medium 3 to be measured based on the height of the measuring cylinder 10, the set height, and two time values.

[0058] The measurement method of this application provides a reference reference with a known set height by setting a reference collar 12. Based on the time value of the radar wave reaching the reference collar 12, the propagation speed of the radar wave in the steam is directly calculated, which completely avoids the dielectric constant and bypasses the problem that the dielectric constant of the steam changes with temperature and pressure. This simplifies the calculation and enables the measurement of higher precision liquid level data.

[0059] Regarding the measurement method, specifically, the waveguide rod 2 is coaxially arranged with the axis of the measuring cylinder 10, that is, the waveguide rod 2 is located in the center of the measuring cylinder 10. The measuring cylinder 10 is connected to the container to be measured 4 through two connecting pipes 11, with both ends of each connecting pipe 11 perpendicular to the side wall of the measuring cylinder 10 and the side wall of the container to be measured 4.

[0060] like Figure 2 As shown, the reference liquid level height H in the test container 4 is...ε Calculation method:

[0061]

[0062] Where h is the known height of the measuring cylinder 10, l0 is the set height between the reference collar 12 and the top wall of the measuring cylinder 10, t0 is the time value of the radar wave reaching the reference collar 12, and t is the time value of the radar wave reaching the surface of the working medium 3 to be measured.

[0063] Specifically, H ε =hl, where l is the height from the liquid surface to the top wall of the measuring cylinder 10.

[0064] The method for calculating the reference liquid level height in this application uses... By directly calculating the propagation speed of radar waves in steam, the algorithm in existing technologies is completely bypassed. (Among them, the dielectric constant ε of steam is related to both steam pressure and steam temperature), which reduces the need for pressure sensors, simplifies the calculation process, and improves measurement accuracy.

[0065] Regarding the measurement method, in one embodiment, in addition to the above technical solution, the measuring device further includes three temperature sensors disposed below the liquid surface. One temperature sensor is disposed inside the container 4 to be measured, and two temperature sensors are disposed at different depths inside the measuring cylinder 10. All three temperature sensors are connected to the radar signal transceiver 1, which is also used to perform density difference compensation on the reference liquid level height based on the temperature data measured by the temperature sensors and the installation dimensions of the connecting pipe relative to the container 4 to be measured and the measuring cylinder 10.

[0066] like Figure 3 As shown, specifically, the liquid level height H after density difference compensation. ερ Calculation method:

[0067]

[0068]

[0069] Where, ρ v The density of the working fluid to be tested inside the container is obtained by looking up a table based on the temperature of the working fluid 3 inside the container. Let be the average density of the working fluid 3 inside the measuring cylinder 10, b be the known height from the lower connecting pipe to the bottom of the measuring cylinder 10, h0 be the known height from the lower connecting pipe to the bottom of the container 4 to be measured, x1 be the known height from one temperature sensor inside the measuring cylinder 10 to the lower connecting pipe, and x2 be the known height from another temperature sensor inside the measuring cylinder 10 to the lower connecting pipe. The corresponding density is obtained by looking up a table based on the known type of working fluid and the temperature measured by two temperature sensors inside the measuring cylinder 10, respectively, by the radar signal transceiver 1.

[0070] in, The basis for this is that the hydraulic pressure at both ends of the lower connecting pipe is equal, therefore the upward density of the lower connecting pipe is inversely proportional to its height.

[0071] in, We assume that the density of the working fluid inside the measuring cylinder 10 changes linearly with the depth.

[0072] The measurement method of this application, after density compensation, eliminates the liquid level height error caused by the uneven density inside the measuring cylinder 10 and the container under test 4 due to indirect measurement. It can simultaneously meet the requirements of easy cleaning and maintenance of the waveguide rod and improved liquid level height measurement accuracy. It is highly practical and widely applicable.

[0073] like Figure 4 and Figure 5 As shown, based on the above technical solution, the liquid level height H after tilt angle compensation is... ερθ for

[0074] H ερθ =H ερ -dcosφtanθ;

[0075]

[0076] Where θ is the angle between the axis of the container under test and the vertical line, α is the longitudinal heel angle of the hull measured by the tilt sensor, β is the transverse heel angle of the hull measured by the tilt sensor, and φ is the angle between the line connecting the top view center of the measuring cylinder and the container under test and the vertical line of navigation (see...). Figure 4 ), d is the distance between the axis of the measuring cylinder and the axis of the container being measured (see Figure 5 ).

[0077] The measurement method of this application, through tilt angle compensation, solves the problem of unstable liquid level measurement caused by ship swaying in the prior art, and further improves the measurement accuracy.

[0078] The measurement method of this application first calculates the reference liquid level height using the reference collar 12, and then performs density difference compensation and tilt angle compensation sequentially. This greatly improves the measurement accuracy of the liquid level height, enhances the adaptability of the measurement, and is unaffected by the dielectric constant or the ship's rolling motion, resulting in a higher liquid level height H after tilt angle compensation. ερθ The measurement accuracy can reach ±1mm.

[0079] Specifically, the liquid level height H after tilt angle compensation ερθ It outputs a current signal of 4-20mA.

[0080] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0081] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0082] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A measuring method of a shipborne guided-wave radar liquid level measuring device, characterized in that, The measuring device cooperates with a radar signal transceiver device (1) and a waveguide (2) to measure the liquid level height in a to-be-measured container (4), and comprises a measuring cylinder (10) with a known height and a reference collar (12). The measuring cylinder (10) is vertically arranged side by side outside the to-be-measured container (4) and is communicated with the to-be-measured container through a communication pipe (11). The waveguide (2) is inserted from the top wall of the measuring cylinder (10), and the radar signal transceiver device (1) is arranged at the top end of the waveguide (2). The reference collar (12) is sleeved on the waveguide (2) and is located between the liquid surface and the top wall of the measuring cylinder (10), and the distance between the reference collar (12) and the top wall of the measuring cylinder (10) is a set height. The measuring method comprises the following steps: The radar signal transceiver device (1) measures two time values of radar waves reaching the reference collar (12) and the liquid surface of the to-be-measured working medium (3); The radar signal transceiver device (1) calculates the reference liquid level height of the to-be-measured working medium (3) according to the height of the measuring cylinder (10), the set height and the two time values; The waveguide rod (2) axis is coaxial with the axis of the measuring cylinder (10), and the measuring cylinder (10) is communicated with the container (4) to be measured through two communication pipes (11) up and down, and the two ends of each communication pipe (11) are perpendicular to the side wall of the measuring cylinder (10) and the side wall of the container (4) to be measured; the calculation method of the reference liquid level height in the container (4) to be measured ​ ； wherein, H is the known height of the measuring cylinder (10), H0 is the set height between the reference collar (12) and the top wall of the measuring cylinder (10), T0 is the time value of the radar wave reaching the reference collar (12), T is the time value of the radar wave reaching the liquid level of the working medium (3) to be measured; The measuring device further comprises three temperature sensors arranged below the liquid surface, one of which is arranged in the to-be-measured container (4) and the other two are arranged at different depths in the measuring cylinder (10); The three temperature sensors are connected to the radar signal transceiver device (1), and the radar signal transceiver device (1) is further used to compensate the reference liquid level height according to the temperature data measured by the temperature sensors and the installation dimensions of the communication pipe relative to the to-be-measured container (4) and the measuring cylinder (10); The density difference compensated liquid level height Calculation method: ； ； wherein, is the density of the working fluid to be measured in the measured container, which is obtained by looking up a table according to the temperature of the working fluid (3) in the measured container; is the average density of the working fluid (3) in the measuring cylinder (10), is the known height from the lower communication pipe to the bottom of the measuring cylinder (10), is the known height from the lower communication pipe to the bottom of the measured container (4), is the known height from one temperature sensor in the measuring cylinder (10) to the lower communication pipe, is the known height from another temperature sensor in the measuring cylinder (10) to the lower communication pipe, are the respective densities obtained by looking up a table according to the temperatures measured by the radar signal transceiver device (1) according to the two temperature sensors in the measuring cylinder (10).

2. The method of measuring the level of a liquid in a ship using the apparatus of claim 1, wherein tilt angle compensated liquid level height for ; ; wherein, is the angle of the axis of the container (4) to be measured relative to the plumb line, is the measured longitudinal inclination of the hull, is the measured transverse inclination of the hull, is the angle between the line connecting the top center of the measuring cylinder and the container to be measured and the sailing vertical line, is the distance between the axis of the measuring cylinder and the axis of the container to be measured.

3. The method of measuring the level of a liquid in a ship using the apparatus of claim 2, wherein the liquid level height after the inclination compensation The measurement accuracy can reach ±1mm.

4. The method of measuring the level of liquid in a ship using the apparatus of claim 2, wherein: the liquid level height after the inclination compensation The current signal of 4-20mA is outputted.

5. The method of measuring the level of liquid in a ship using the device according to claim 1, characterized in that: The measuring device further comprises two inclination sensors arranged in the transverse and longitudinal directions of the ship body, and the two inclination sensors are connected to the radar signal transceiver device (1). The radar signal transceiver device (1) is further used to compensate the liquid level height according to the transverse inclination and the longitudinal inclination measured by the inclination sensors.

Images