CN100356145C - System and method in a radar level gauging system - Google Patents

System and method in a radar level gauging system Download PDF

Info

Publication number
CN100356145C
CN100356145C CNB200480007697XA CN200480007697A CN100356145C CN 100356145 C CN100356145 C CN 100356145C CN B200480007697X A CNB200480007697X A CN B200480007697XA CN 200480007697 A CN200480007697 A CN 200480007697A CN 100356145 C CN100356145 C CN 100356145C
Authority
CN
China
Prior art keywords
product
liquid level
value
level
capacitance probe
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CNB200480007697XA
Other languages
Chinese (zh)
Other versions
CN1761858A (en
Inventor
莱纳特·哈格
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rosemount Tank Radar AB
Original Assignee
Saab Rosemount Tank Radar AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Saab Rosemount Tank Radar AB filed Critical Saab Rosemount Tank Radar AB
Publication of CN1761858A publication Critical patent/CN1761858A/en
Application granted granted Critical
Publication of CN100356145C publication Critical patent/CN100356145C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)

Abstract

The present invention relates to the field of radar level gauging systems, in which a level of a surface (12) of a product (16) stored in a container (10) is measured. The gauging system comprises: a radar level gauge (14) arranged above the surface (12) of the product (16) which is arranged to transmit a microwave signal towards the product surface (12) and receive a reflected microwave signal from the product surface(12); a calculation unit arranged to determine a measured value of the product level based upon the received signal; means for comparing the measured value of the product level with a predetermined value; and a second level gauge (20) arranged closed to the bottom of the container (10) and arranged to determine the product level when the measured value is below the predetermined value.

Description

System and method in the radar level gauging system
Technical field
The present invention relates to radar level gauging system, when particularly relating to a kind of liquid level in container, improve the radar level gauging system and the measuring method of the accuracy of measuring the liquid level that is stored in liquid in containers near container bottom.
Background technology
Radar level gauging is generally to be used for now measuring being stored in container, and as the device of the liquid level of the liquid in the oil tank, it receives then from the microwave signal of liquid surface reflection, thereby can determine liquid level by to liquid level launched microwave signal.Importantly, when liquid level during near the bottom, the user can access reading accurately, and can detection receptacle when become empty.
A problem is that when liquid had low specific inductive capacity, the major part of reflected signal was next from the surface reflection of container bottom rather than liquid especially.This can produce distorted signal, removes the filling liquid level height of on-liquid because by the signal of bottom reflection by Liquid Absorption.When liquid is that this problem will constantly increase when hanging down liquid level at large.
Another problem is the bottom section at container, almost total by-product layer, and water for example, its separation owing to liquid, concentrated etc. produces.And when the specific inductive capacity of secondary product is high relatively, a reflected signal that is better than liquid surface will be sent in the interface of secondary product.
Therefore, the radar level gauging device of previously known just has during near the measurement of container bottom in measuring the container of storage of liquids and has limited to.
Summary of the invention
Therefore, when an object of the present invention is to provide the level that a kind of measurement is stored in the surface of the product in the container is the improved method of sky with liquid level and the detection receptacle of allow measuring near container bottom.
Purpose of the present invention realizes that by using following measuring method the method comprising the steps of: the radar level gauging device by being installed in the product surface top is to product surface launched microwave signal; In described radargrammetry device, receive from the microwave signal of product surface reflection; In computing unit, determine the measured value of product liquid level based on the signal that receives; The relatively measured value of this product liquid level and predefined product fluid value; And when this measured value is lower than the predetermined prod fluid value, use second liquid surface measuring device that is installed in container bottom to determine the product liquid level.
Another object of the present invention provides a kind of improved level gauging system, is used for measuring the liquid level on the surface of the product that is stored in container, when is sky with liquid level and the detection receptacle that allows to measure near container bottom.
This purpose realizes by the level gauging system that provides following being used for to measure to be stored in the liquid level of container product, this system comprises: the radar level gauging device that is installed in the product top, this installs to product surface launched microwave signal, and receives the microwave signal of reflection from product surface; Computing unit is used for determining based on the signal that is received the measured value of the liquid level of product; Be used for the device of measured value and predefined product fluid value of comparative product liquid level; With, being installed in second liquid surface measuring device that approaches container bottom, it is used for measuring the liquid level of product when measured value is lower than preset value.
The other objects and features of the invention are from below in conjunction with becoming obvious the detailed description of accompanying drawing.Yet, should be understood that the accompanying drawing purpose only be to explanation of the present invention and, be not to be used for limiting definition of the present invention, the reference of limitation of the present invention should be made by appended claims.Should be appreciated that more accompanying drawing needn't proportionally draw, unless otherwise indicated, otherwise their purpose only is in this description scheme and the conceptual demonstration of step.
Description of drawings
In institute's drawings attached, the identical identical unit of numeric character indication.
Fig. 1 discloses the synoptic diagram that is installed in according to the container in the radar level gauging system of the present invention.
Fig. 2 has shown the synoptic diagram according to the container of Fig. 1, and wherein, the product liquid level in the container is lower than the product liquid level among Fig. 1.
Fig. 3 is the process flow diagram of the creative method of the present invention of execution when being presented at container for sky.
Fig. 4 is the process flow diagram of the creative method of the present invention carried out when being presented at container and being full of.
Embodiment
With reference to figure 1 and Fig. 2, be often referred to and be shown 10 container and be full of liquid 16, the height of liquid or liquid level are determined with radar level gauge 14.Radar level gauge 14 is preferably installed and is sealed on the container port on container 10 tops and with respect to its sealing.Radar level gauge 14 comprises an antenna 18, and antenna 18 is to liquid surface 12 launched microwaves, and receives the reflected microwave signal from liquid surface 12, thereby the indication of the liquid level of liquid 16 in the container 10 is provided.The radar level gauge 14 that is used for launched microwave and reception reflected microwave signal is known, and only schematically shows at this.
An interface determinator 20 is mounted close to the bottom of container 10.Interface determinator 20 is used to measure the liquid level or the level 24 of secondary product 22, and this liquid level is for example because the separation of liquid 16 or concentrate and raise.Radar measuring device 14 and interface determinator 20 interconnect (not shown).In the time of the reflected signal poor quality that receives when radar level gauge or when the level gaging value of liquid surface 12 reaches predetermined value, for example, when the filling liquid level of liquid is low, it is such that image pattern 2 is represented, installation radar measuring device is used for instructing interface-measuring device to recalibrate and comes work as liquid surface measuring device rather than as interface-measuring device.In this article, and term " measured value " be meant with rice the value of the liquid level that is the unit measurement, that is, and the height of tested liquid level.
Preset value is based on experience, and is stored in the radar level gauge 14.When the filling liquid level of liquid 16 was low, the operator was from interface determinator 20 rather than obtain the information of relevant liquid level from radar level gauge 14.The change of this determinator is sightless to the operator.Perhaps, if the operator needs, can provide the liquid level information that obtains from these two level gauge simultaneously.
Interface determinator 20 is reference point (its value preferably is stored in the interface-measuring device 20) by the specific inductive capacity that uses air, and have how many interface-measuring devices 20 to be immersed in the liquid (value that provides by radar level gauge 20), thereby come the liquid level rather than the interface 24 between secondary product 22 and liquid 16 of calibration measurement liquid surface 12 as the range calibration point by use.
In a preferred embodiment of the invention, container is the oil tank that oil is housed.Oil, particularly crude oil all can comprise some water usually, and these water will separate and accumulate in tank bottom from crude oil.In order to determine that how much water is arranged in the oil tank, a water interface gauge is installed in tank bottom.Water interface gauge in the preferred embodiment of the present invention is a capacitance probe.
Capacitance probe uses a kind of like this relation, i.e. electric capacity change and specific inductive capacity are directly proportional.For example, the example of some specific inductive capacity is air-1, oil-4, ethanol-25, water-80.Capacitance probe is known to those skilled in the art, does not go through in this application.Radar level gauge 14 and capacitance probe 20 preferably communicate by the HART agreement.
Usually, capacitance probe knows that the specific inductive capacity of product is necessary.This can have problems when product is the situation of profit mixing, because can not learn specific inductive capacity from bad measurement data result.But in this application, do not need to know in advance specific inductive capacity.This is that promptly, capacitance probe is calibrated by the range calibration point (detector is immersed in the length in the product) that is provided by radar level gauge, thereby can calculate the specific inductive capacity of liquid at an easy rate because of a kind of like this fact.
In the preferred embodiment of the application, when container 10 when empty in the measuring vessel 10 storage liquid 16 liquid surface 12 step as shown in Figure 3, as follows:
1. radar level gauge 14 is by measuring the liquid level (step 31) of liquid surface 12 from the microwave reflection of liquid surface 12 to liquid plane 12 launched microwaves and reception.
2. measured value X compares (step 32) with the predetermined value Y that is stored in the radar level gauge 14.If measured value X is higher than predetermined value Y, then radar level gauge 14 is equal to or less than predetermined value Y according to the height of step 31 measurement liquid surface 12 up to measured value X.
3. when measured value X is equal to or less than predetermined value Y, radar level gauge 14 instruction capacitance probe 20 calibration measurement liquid surfaces 12 rather than water terminations 24 (step 33).Water interface gauge 20 is by using dielectric constant of air as neutral point (this value preferably is stored in the capacitance probe 20), what and have water termination detectors 20 to be dipped in the liquid (value that provides by radar level gauge 14), thereby calibrate as the range calibration point by use.
4. capacitance probe 20 is measured the liquid level (step 34) of liquid surface 12, that is, the interface of air and liquid, this measuring process is to change the fact that is directly proportional with the specific inductive capacity of liquid 16 by the electric capacity that utilizes detector 20 to realize.
In this preferred embodiment of the application, when container 10 was filled with, as shown in Figure 4, the step of the liquid level of the liquid surface 12 of liquid 16 was as follows in the measuring vessel 10:
1. capacitance probe 20 is measured the liquid level (step 41) of liquid surface 12, that is, the interface of liquid and air, this process is to change the fact that is directly proportional with the specific inductive capacity of liquid 16 by the electric capacity of using detector 20 to realize.
2. measured value X compares (step 42) with the predetermined value Y that is stored in the radar level gauge 14.If measured value X is equal to or less than predetermined value Y, then capacitance probe 20 is according to the liquid level of step 41 measurement liquid surface 12, till measured value X is higher than predetermined value Y.
3. when measured value X is higher than predetermined value Y, radar level gauge 14 instruction capacitance probes 20 calibration measurement water terminations 24, i.e. the interface of water 22 and liquid 16, rather than measure the liquid level (step 43) of liquid surface 12.Capacitance probe 20 is calibrated by the calibration point (neutral point and range calibration point) (these preferably manufactured merchants of point are stored in capacitance probe 20) that use is used for water termination 24 measurements.
4. radar level gauge 14 is by also receiving the liquid level (step 44) of measuring liquid surface 12 from the microwave reflection of liquid surface 12 to liquid surface 12 launched microwaves.
Therefore, though the novel features of being implemented by preferred embodiment of the present invention is shown and describes and points out, but should be understood that, the various forms of omissions of the details of the design shown in those skilled in the art can make under the situation that does not break away from spirit of the present invention and form and their enforcement replace and change.For example, clearly all within the scope of the invention, these combinations have been carried out same function in fact, used with quadrat method and have been obtained same effect in the combination of these key elements and/or method.And, will be appreciated that, among any form disclosed by the invention and the embodiment disclosed structure and/or key element and/or method step can be included in any other open describe or the form of suggestion or embodiment in as the routine of a design.Therefore, the present invention is only limited by appended claim.

Claims (8)

1. a measurement is stored in the method for liquid level on the surface of the product in the container, comprises the steps:
With the radar level gauging device that is installed in product surface top to product surface launched microwave signal;
In described radar level gauging device, receive from the microwave signal of product surface reflection;
In computing unit, determine the measured value of product liquid level based on the signal that receives;
The predetermined value of comparative product liquid level gauging value and product liquid level;
When measured value is less than or equal to predetermined product fluid value, use a capacitance probe of installing near container bottom to determine the product liquid level.
2. method as claimed in claim 1 further comprises when the measured value of product liquid level is higher than the predetermined value of product liquid level, the step of the liquid level by product in this capacitance probe measuring vessel and the boundary between the secondary product.
3. method as claimed in claim 1 further comprises by means of described capacitance probe, determines the step of product liquid level by the specific inductive capacity of product around the calculating capacitance probe.
4. method as claimed in claim 3 further comprises the step of calibration capacitance detector, and this step is finished by following:
The specific inductive capacity that utilizes air is as neutral point;
The value of the detector length that is dipped in the product is provided by the radar level gauging device;
Calculate the actual value of specific inductive capacity by capacitance probe; With
The specific inductive capacity that uses described calculating is as the range calibration point corresponding to described length.
5, a kind of measurement is stored in the radar level gauging system of the liquid level on the surface (12) of product (16) in the container (10), comprising:
Be installed in the radar level gauging device (14) of the top, surface (12) of product (16), this radar level gauging device (14) is configured to product surface (12) launched microwave signal, and receives from the microwave signal of product surface (12) reflection;
Determine the computing unit of the measured value of product liquid level according to the signal that is received;
The device that is used for the predetermined value of the measured value of comparative product liquid level and product liquid level;
Near the capacitance probe (20) that install container (10) bottom, it is configured to determine the product liquid level when measured value is less than or equal to product liquid level predetermined value.
6, radar level gauging system as claimed in claim 5, wherein, when the measured value of product liquid level was higher than the predetermined value of product liquid level, this capacitance probe (20) was configured to the liquid level of the boundary (24) between middle product (16) of measuring vessel (10) and the secondary product (22).
7, radar level gauging system as claimed in claim 5, wherein, described capacitance probe is configured to use the specific inductive capacity of product (16) and the specific inductive capacity of air to determine the product liquid level.
8, radar level gauging system as claimed in claim 6, wherein, described capacitance probe (20) is provided for determining the liquid level of product, be configured to the measurement products liquid level and carry out describedly determining by capacitance probe (20) boundary (24) between product (16) and the secondary product (22) from be configured to measuring vessel (10) is calibrated to, wherein, neutral point as the specific inductive capacity of air, and the range calibration point is applied to described calibration steps, and wherein said range calibration point is provided by the radar level gauging device, immerse the specific inductive capacity of calculating of value of the length of product (16) corresponding to detector (20).
CNB200480007697XA 2003-03-21 2004-03-05 System and method in a radar level gauging system Expired - Fee Related CN100356145C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US10/393,371 2003-03-21
SE03008190 2003-03-21
SE0300819A SE0300819D0 (en) 2003-03-21 2003-03-21 System and method in a radar level gauging system

Publications (2)

Publication Number Publication Date
CN1761858A CN1761858A (en) 2006-04-19
CN100356145C true CN100356145C (en) 2007-12-19

Family

ID=20290777

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB200480007697XA Expired - Fee Related CN100356145C (en) 2003-03-21 2004-03-05 System and method in a radar level gauging system

Country Status (2)

Country Link
CN (1) CN100356145C (en)
SE (1) SE0300819D0 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7541969B2 (en) * 2007-05-31 2009-06-02 Rosemount Tank Radar Ab Radar level gauging system for use at sea
NL1034327C2 (en) * 2007-09-04 2009-03-05 Enraf Bv Method and device for determining the level L of a liquid within a certain measuring range with the aid of radar signals radiated to the liquid level and radar signals reflected by the liquid level.
US7525476B1 (en) * 2007-11-13 2009-04-28 Rosemount Tank Radar Ab System and method for filling level determination
DE102011106003A1 (en) * 2011-06-30 2013-01-03 Linde Ag Method for determining level of liquid neon in medium container utilized in neon liquefaction system, involves connecting capacitive level measuring device with medium container, and determining level of medium by measuring device
CN102343969B (en) * 2011-07-20 2013-10-09 中国船舶重工集团公司第七○二研究所 Liquid tank without free liquid level
DE102016101756A1 (en) * 2016-02-01 2017-08-03 Vega Grieshaber Kg Method for determining and displaying the optimum material thickness in level measurement with radar sensors
CN106052603A (en) * 2016-07-04 2016-10-26 重庆大学 Bridge flexibility monitoring system
CN109520593A (en) * 2018-11-27 2019-03-26 青岛大学 A kind of detection method using auto-alarming guide wave radar liquid level gauge
CN109520591B (en) * 2018-12-10 2020-11-06 中国核动力研究设计院 Novel resin interface liquid level meter and resin interface measuring method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1174395A (en) * 1966-04-25 1969-12-17 Fielden Electronics Ltd Improvements in or relating to Level Indicators
US5070730A (en) * 1989-04-10 1991-12-10 Saab Marine Electronics Aktiebolag Device for level gauging with microwaves
US5614831A (en) * 1995-02-13 1997-03-25 Saab Marine Electronics Ab Method and apparatus for level gauging using radar in floating roof tanks
WO1998024013A2 (en) * 1996-10-07 1998-06-04 Berwind Corporation Material interface level sensing
SE512510C2 (en) * 1998-10-06 2000-03-27 Saab Marine Electronics Measuring device for level of medium inside tank, uses sensor to record changes in distance between tank roof and the device, in order to compensate for any tank roof movement

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1174395A (en) * 1966-04-25 1969-12-17 Fielden Electronics Ltd Improvements in or relating to Level Indicators
US5070730A (en) * 1989-04-10 1991-12-10 Saab Marine Electronics Aktiebolag Device for level gauging with microwaves
US5614831A (en) * 1995-02-13 1997-03-25 Saab Marine Electronics Ab Method and apparatus for level gauging using radar in floating roof tanks
WO1998024013A2 (en) * 1996-10-07 1998-06-04 Berwind Corporation Material interface level sensing
SE512510C2 (en) * 1998-10-06 2000-03-27 Saab Marine Electronics Measuring device for level of medium inside tank, uses sensor to record changes in distance between tank roof and the device, in order to compensate for any tank roof movement

Also Published As

Publication number Publication date
SE0300819D0 (en) 2003-03-21
CN1761858A (en) 2006-04-19

Similar Documents

Publication Publication Date Title
US20080060431A1 (en) Radar level gauging
US20150033830A1 (en) Automated phase separation and fuel quality sensor
EP2722655B1 (en) Guided wave radar interface measurement medium identification
US8746045B2 (en) System and method for identifying fluids and monitoring fluid quality in a vessel
CN101896797B (en) For the method for level gauging
US6857313B2 (en) Self-calibrating capacitance gauge
EP2166321A2 (en) Method for robust gauging accuracy for level gauges under mismatch and large opening effects in stillpipes and related apparatus
CN101297182B (en) Level gauge
CN100356145C (en) System and method in a radar level gauging system
US7523661B2 (en) Methods and systems for liquid volumetric measurement
US6828930B2 (en) System and method in a radar level gauging system
JPS60159615A (en) Level indicator
US10114139B1 (en) Multi-capacitor liquid detection device and method(s) of use
CN111693109A (en) Multifunctional storage tank liquid level meter
CN103733033A (en) Linear relationship between tracks
CN108344465A (en) Method and device for measuring liquid level based on liquid temperature
US20210172786A1 (en) Fill level measuring device
US20200125974A1 (en) Method for determining a process variable with a classifier for selecting a model for determining the process variable
US11747187B2 (en) Method for generating a masking curve for a fill state measuring device
US20110167904A1 (en) Method of using a level meter employing the radar principle
Yahya A multi-level storage tank gauging and monitoring system using a nanosecond pulse
CN116124664B (en) Flotation foam measurement equipment and calibration method
US11454942B2 (en) Method for starting up a field device in a simplified manner
RU2776192C1 (en) Method for measurement of level of dielectric liquid in container
RU2239790C2 (en) Method of measuring fluid level in tanks

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
C17 Cessation of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20071219

Termination date: 20100305