CN1212507C

CN1212507C - New method of liquid state environment different medium interface measurement

Info

Publication number: CN1212507C
Application number: CN 03157535
Authority: CN
Inventors: 王广涛
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-09-24
Filing date: 2003-09-24
Publication date: 2005-07-27
Anticipated expiration: 2023-09-24
Also published as: CN1493878A

Abstract

The present invention provides a new method for measuring different medium interfaces in liquid state environment, and relates to a method for measuring the interface of two kinds of liquid. The method can be used for detecting the interface of two kinds of liquid in an oil storage tank body in petroleum or petrochemical industry. The method comprises the steps that three groups of pressure sensors are fixed on a measuring device with a long fixed rod in a top and bottom direction at intervals; the lower end of the measuring device extends in liquid, and the two pressure sensors of the lower part enter the top and bottom range of the liquid interface; pressure analog signals detected by the sensors are transmitted to an analog-digital conversion circuit and converted into digital signals, and then, the digital signals are transmitted to a CPU single-chip computer; and finally, by remote transmission excitation, processing results are inputted to a computer by long distance and are displayed or printed. The method overcomes various defects of difficult operation, difficult realization and imprecise measuring results for the past measuring method, and can be used for measuring a plurality of parameters, comprising liquid density, liquid levels, temperature, etc. The method has the advantages of advanced instrument, convenient supervision, observation and operation and high precision of measuring results, and is widely used for the technical field of the detection of the interface of two kinds of liquid.

Description

The new method that liquid environment different medium interface is measured

Technical field

The present invention relates to the new method of two kinds of liquid surfaces of a kind of measurement, can be used for the detection of two kinds of liquid surfaces in oil or the petrochemical industry oil storage tank body.

Background technology

There are a lot of places need measure two kinds of interfaces between the fluent meterial, especially oil or chemical industry, the liquid that stores in the storage tank of petroleum products, generally all contain water, if do not know the interface of two kinds of liquid, just can't calculate the content of every kind of liquid, also often need to know other correlation parameter relevant sometimes with liquid.The method of using is too backward at present, not science.Its method commonly used is, the valve by tank base discharges water, and treats to turn off valve when fuel-displaced, measures the degree of depth of oil again, can calculate fuel-displaced general assembly (TW), and oily drain tank is very dangerous outward, causes fire easily.Also have by the tank skin connection container and in container with the method for built-in ball float measurement liquid surface, the liquid of different specific weight need use the ball float of different specific weight, and the manufacturing process of ball float is very complicated, has increased use cost.The measuring method that these all are to use mechanical hook-up is difficult to operation, is difficult to realize, and the failure rate height, the out of true as a result of measurement can't be measured other parameter of liquid.

Summary of the invention

In order to overcome the deficiencies in the prior art, the invention provides the new method that a kind of liquid environment different medium interface is measured, this method has been used a kind of brand-new measuring technique, overcome that measuring method was not easy to operate in the past, be difficult for realizing, the coarse various defectives of measurement result, this method not only can be measured two kinds of interfaces between the liquid, can also measure density of liquid in the storage tank, liquid level, interface multiple parameters between temperature and the two kinds of liquid, the instrument advanced person that this method is used, computing machine is introduced the test process of its liquid surface, be convenient to monitoring, observe and operation, computing machine shows result of calculation or printout, very directly perceived, this method is very easy to realize its test result precision height.

The invention provides such technical scheme: the new method that a kind of liquid environment different medium interface is measured, described interface assay method carries out according to following step, according to certain spacing be fixed on the measurement mechanism that have long fixed bar on according to above-below direction three groups of pressure transducers, with reference to the height of conventional tank body and the height at interface, the measurement mechanism lower end is stretched in the liquid, two pressure transducers in bottom are entered in the top/bottom latitude of liquid surface, the pressure simulation signal that three pressure transducers are measured imports the AD analog to digital conversion circuit into, the AD analog to digital conversion circuit imports the CPU single-chip microcomputer into after analog signal conversion is become digital signal, and the CPU single-chip microcomputer imports result into computing machine.

Described single-chip microcomputer is given computing machine with result through teletransmission excitation long-distance transmissions.

The invention has the advantages that: owing to used a plurality of pressure transducers and AD analog to digital conversion circuit, the AD analog to digital conversion circuit becomes digital signal with the analog signal conversion of pressure transducer, input to single-chip microcomputer, single-chip microcomputer transfers out to computing machine after with its data processing, computing machine can calculate two kinds of interfaces between the liquid according to certain calculation method, the use of teletransmission excitation has guaranteed the telecommunication scheme of measuring instrument and computing machine in the circuit structure, in use, liquid surface altitude range according to routine, the aluminum pipe that sensor is installed is stretched in the scope of interface, can measure the various data that need, computing machine can show or the various results of printout at last.This measuring method is simple and reliable, realizes that easily the measuring accuracy height has overcome the defective of measuring method in the past.

Below in conjunction with description of drawings concrete measuring process of the present invention.

Description of drawings

Fig. 1 is the structural representation that the present invention uses measuring instrument.

Fig. 2 is the synoptic diagram of measuring instrument of the present invention when being positioned at tank body and using.

Fig. 3 is a schematic block circuit diagram of the present invention.

Fig. 4 is the theory diagram of power circuit of the present invention.

Fig. 5 is circuit theory diagrams of the present invention.

Embodiment

The new method that a kind of liquid environment different medium interface is measured, described interface assay method carries out according to following step, according to certain spacing be fixed on the measurement mechanism that have long fixed bar on according to above-below direction three groups of pressure transducers, as Fig. 1, shown in Figure 2, with reference to the height of conventional tank body and the height at interface, as shown in Figure 2, the measurement mechanism lower end is stretched in the liquid, two pressure transducers in bottom are entered in the top/bottom latitude of liquid surface, as Fig. 3, Fig. 4, shown in Figure 5, the pressure simulation signal that three pressure transducers are measured imports the AD analog to digital conversion circuit into, the AD analog to digital conversion circuit imports the CPU single-chip microcomputer into after analog signal conversion is become digital signal, the CPU single-chip microcomputer is given computing machine with result through teletransmission excitation long-distance transmissions, shows or printout after calculating the result by computing machine according to certain calculation method.

As shown in Figure 1 and Figure 2, the employed measurement mechanism of this method is made up of aluminum pipe 1, fixed bar 6, three

pressure transducers

2,3,5 and temperature sensor 4, and temperature sensor 4 can directly test out the temperature of liquid.The main body 10 of its measurement mechanism is an aluminum pipe 1 that certain-length is arranged, aluminum pipe 1 top is connected with fixed bar 6, by certain distance three

pressure transducers

2,3,5 are installed along the vertical direction on the aluminum pipe 1, sensor is fixed on the sidewall of aluminum pipe 1, and temperature sensor 4 is installed in the aluminum pipe 1.

As Fig. 3, Fig. 4, shown in Figure 5, the circuit of measurement mechanism that this method is used is by pressure sensor part, temperature sensor section, AD analog to digital conversion circuit part, the CPU single-chip microcomputer, teletransmission excitation and power unit are formed, pressure sensor part is by first pressure transducer, second pressure transducer and the 3rd pressure transducer are formed, three pressure transducers connect the signal input part AIN1-AIN6 of AD modulus conversion chip U1 respectively by electric connector J1, the output signal of temperature sensor directly connects the input end P17 of CPU single-chip microcomputer, the signal output part of AD modulus conversion chip U1 connects the signal input part P10-P13 of CPU single-chip microcomputer U3, two connection RXD of CPU single-chip microcomputer U3, TXD is respectively by two groups of teletransmission excitation U4A, U4B, U4C connect in order to the communication interface J12 of computing machine communication, the dc output end of power unit connects the dc supply end of chip.

The model of CPU single-chip microcomputer U3 can be 89C51, and the model of AD modulus conversion chip can be AD7708, and pressure transducer can be a diffusion silicon pressure sensor, also can be capacitance type sensor.

Process below in conjunction with its Computer Processing of description of drawings and result of calculation.

As Fig. 1, shown in Figure 2, first pressure transducer 2, second pressure transducer 3, the force value of the 3rd pressure transducer 5 correspondences is assumed to be Fa respectively, Fb, Fc, distance between first pressure transducer 2 and second pressure transducer 3 is assumed to be Δ Hab, distance between second pressure transducer 3 and the 3rd pressure transducer 5 is assumed to be Δ Hbc, under normal conditions, the oil 9 of conventional tank body 8, water 12 interfacial levels are about 2000mm, we are made into Δ Hab=400mm with measuring instrument, Δ Hbc=1000mm, the length of fixed bar is pressed the common height of tank body and is made, to guarantee that measuring instrument 10 gos deep into the liquid surface scope and installs, during installation, allow between interface Jie and the BC.

The first step can be obtained the height of liquid level.

According to the test result of three

pressure transducers

2,3,5, can learn that 3 observed pressure value is respectively Fa, Fb, Fc, can obtain Δ fab=Fb-Fa, Δ fbc=Fc-Fb, because F=ρ gh, so Δ fab/fb=Δ Hab/ (H _{Liquid level}-Hb)=400/ (H _{Liquid level}-Hb), the height of Hb can determine to learn that Δ fab, fb, Hb are known quantity in the formula according to the installation site of instrument, thereby can obtain H _{Liquid level}Data.

Second step can be obtained density of liquid.According to formula F=ρ gh, be easy to try to achieve the data of density of liquid ρ.

The 3rd step can be obtained the interface of liquid.

By the test result of pressure transducer, can directly obtain the force value Δ fbc of actual measurement _{Actual measurement},, can obtain calculation of pressure value Δ fbc according to formula F=ρ gh _Calculate, H _{Interface C}Be the distance of ordering from C in the interface, H _InstallThe height at the 5 distance jar ends of the 3rd pressure transducer is known numbers when being the measuring instrument installation, can directly obtain H according to following formula _{The interface}Height:

(Δ fbc _{Actual measurement}/ Δ fbc _Calculate) * (Δ Hbc)=H _{Interface C}+ H _Install=H _{The interface}

Test out H as a result thus _{Liquid level}, H _{Interface C}And parameter such as density of liquid ρ, after these computing method are handled the pressure data of sensor measurement by surveying instrument 10, directly being transferred to computing machine finishes, its method of testing very easily realizes, this measuring instrument is not limited to the interface level measurement of petroleum products, can also be used for the liquid level test of other liquid chemical products.

Based on design concept of the present invention; the mechanical installation mode and the circuit structure of this invention institute use surveying instrument are not limited to scope disclosed by the invention; every three pressure transducers are installed the method for coming test liquid interface and correlation parameter with the computing machine communication up and down by certain distance; all within protection scope of the present invention, directly the metering system that sensor is installed on the tank body also belongs to protection scheme of the present utility model.

Claims

1. the new method measured of a liquid environment different medium interface, it is characterized in that: described interface assay method carries out according to following step, according to certain spacing be fixed on the measurement mechanism that have long fixed bar on according to above-below direction three groups of pressure transducers, with reference to the height of conventional tank body and the height at interface, the measurement mechanism lower end is stretched in the liquid, two pressure transducers in bottom are entered in the top/bottom latitude of liquid surface, the pressure simulation signal that three pressure transducers are measured imports the AD analog to digital conversion circuit into, the AD analog to digital conversion circuit imports the CPU single-chip microcomputer into after analog signal conversion is become digital signal, and the CPU single-chip microcomputer imports result into computing machine.

2. the new method that liquid environment different medium as claimed in claim 1 interface is measured is characterized in that: described single-chip microcomputer is given computing machine with result through teletransmission excitation long-distance transmissions.

3. the new method that liquid environment different medium as claimed in claim 1 interface is measured, it is characterized in that: described interface is the interface of crude oil with water.

4. the new method that liquid environment different medium as claimed in claim 1 interface is measured, it is characterized in that: described interface is the interface of two kinds of chemicals.