CN202494656U - On-line crude oil low-water content sensor - Google Patents

Abstract

The utility model relates to an on-line sensor with low water content in crude oil, which comprises a sensor body and a built-in circuit. The sensor body is a coaxial capacitor (CX) with crude oil emulsion as a medium, and the built-in circuit is a capacitor frequency conversion circuit. The capacitor The frequency conversion circuit includes an oscillating circuit, which is used to convert the capacitance value into a frequency signal, a push-pull amplifier circuit, which amplifies the frequency signal, and its output terminal is connected to the input terminal of the water content analyzer in crude oil, and a signal stabilization circuit. The circuit guarantees stable operation of the oscillation circuit and the push-pull amplifier circuit. The utility model has the advantages of simple structure, reasonable design, low maintenance rate, on-line maintenance, stable and reliable work, measuring range: 0-3%, accuracy: ±0.05%, power line and signal line collinear, strong anti-interference, basic It is not affected by pressure and flow rate, and is suitable for environments containing explosive gases (steam) of Class A and Class B T1--T6 groups in factories.

Description

On-line crude oil low water content sensor

technical field

The utility model relates to a sensor, in particular to a sensor for measuring the low water content of crude oil in the development and production process of crude oil. the

Background technique

At present, most domestic sensors for measuring low water content of crude oil use ultrashort wave method, microwave method, and radio frequency method, and the accuracy can only reach 0.1%. But now the oilfield crude oil dehydration technology level is very high, and the water content of the purified crude oil exported is generally between 0.1% and 0.25%. If the water content exceeds 0.3%, it needs to be dealt with in time, so the performance of the sensor with an accuracy of 0.1% cannot meet the actual production requirements. Therefore, the research and development of high-quality crude oil low water content sensor can improve the measurement accuracy of water content to ±0.05%, which has considerable social and economic benefits. the

Contents of the invention

The purpose of the utility model is to overcome the disadvantages of the above-mentioned technologies, and provide an online crude oil low water content sensor with simple structure, reasonable design, convenient use and maintenance, high measurement accuracy and stable operation. the

In order to achieve the above object, the technical scheme adopted by the utility model is: comprising a sensor body and a built-in circuit, the sensor body is a coaxial capacitor CX with crude oil emulsion as a medium, and the built-in circuit is a capacitance frequency conversion circuit, and the capacitance frequency The conversion circuit includes an oscillating circuit, which is used to convert the capacitance value into a frequency signal, a push-pull amplifier circuit, which amplifies the frequency signal, and its output terminal is connected to the input terminal of the crude oil water content analyzer, and a signal stabilization circuit, this circuit Ensure the stable operation of the oscillation circuit and the push-pull amplifier circuit. the

The utility model has the advantages of:

1. Measuring range: 0~3%, accuracy: ±0.05%;

2. The power line and the signal line are collinear, and the anti-interference is strong;

3. Basically not affected by pressure and flow rate;

4. Simple structure, reasonable design, low maintenance rate, online maintenance, stable and reliable work;

5. It is suitable for the environment containing explosive gas (steam) of Class A and Class B T1--T6 in the factory. the

Description of drawings

Figure 1 is a schematic diagram of the crude oil low water content sensor circuit;

Detailed ways

Embodiments of the utility model are described in further detail below in conjunction with the accompanying drawings. the

As can be seen from Figure 1, the utility model includes a sensor body and a built-in circuit, the sensor body is a coaxial capacitor CX with crude oil emulsion as a medium, the built-in circuit is a capacitance-frequency conversion circuit, and the capacitance-frequency conversion circuit includes an oscillating circuit 3. It is used to convert the capacitance value into a frequency signal, a push-pull amplifier circuit 1, this circuit amplifies the frequency signal, its output terminal is connected to the input terminal of the crude oil water content analyzer, a signal stabilization circuit 2, this circuit guarantees the oscillation circuit 3 and the push-pull amplifier circuit 1 work stably. the

The oscillating circuit 3 is composed of capacitors C3, C4, C7, C8, C9, an inductor L1 and a coaxial capacitor CX, and one end of the capacitors C7, C8, C9 and the coaxial capacitor CX is connected in parallel to one end of the inductor L1. Capacitors C7, C8, C9 and coaxial capacitor CX are connected in parallel and the other end is grounded. After capacitor C3 and capacitor C4 are connected in series, one end of capacitor C3 is connected to the other end of inductor L1, and the other end of capacitor C4 is grounded. the

The push-pull amplifier circuit 1 is composed of resistors R2-R5, diodes D1, D2 and capacitor C2, the frequency signal generated by the oscillation circuit 3 is input by one end of the capacitor C2, and the amplified frequency signal passes through the common circuit of resistor R4 and resistor R5. The terminal is output by one end of the capacitor C1, the other end of the capacitor C2 is connected to the base of the transistor Q2 through the resistor R3, and the emitter of the transistor Q2 is connected to the collector of the transistor Q1 through the resistor R4 and the resistor R5 successively. The base of transistor Q2 is connected to the base of transistor Q1 through diode D2 and diode D3 in turn, and the base of transistor Q2 is connected to the collector of transistor Q2 through resistor R2. The collector of transistor Q2 is connected to the collector through diode D1 and resistor R1 is connected to the power supply, and the emitter of the transistor Q1 is grounded. the

The signal stabilization circuit 2 is composed of a transistor Q3, resistors R8-R13 and capacitors C6 and C11. The collector of the transistor Q3 is connected to the common end of the capacitors C2, C3 and inductor L1 through the capacitor C5. The transistor Q3 The emitter is connected to the common terminal of the capacitors C3 and C4, the base of the transistor Q3 is connected to the collector of the transistor Q2 through the resistors R6 and R8, the base of the transistor Q3 is connected to the collector through the resistor R8, the resistor R9, and the resistor R10 in turn Connected, resistor R11 and capacitor C6 are connected in parallel, one end is grounded, and the other end is connected to the base of transistor Q3, the collector of transistor Q3 passes through resistor R10, resistor R9, capacitor C11, resistor R13, resistor R12 and the emitter of transistor Q3 in turn The poles are connected, and the common end of the capacitor C11 and the resistor R13 is grounded. the

It has only two lead-out lines, and the power line and the signal line are in the same line. the

The base of the triode Q1 of the oscillation circuit 3 is connected with a resistor R7 and grounded. the

The coaxial capacitor CX of the utility model is the crude oil low water content sensor itself. It uses the crude oil emulsion as the medium. After its structural size is determined, the capacitance of the coaxial capacitor CX is only related to the dielectric constant of the crude oil emulsion. When the dielectric constant of crude oil emulsion is less than 10% water content, the water content of crude oil emulsion has a linear relationship with the dielectric constant. Therefore, when the water content of the crude oil emulsion changes within the range of 0-3%, the capacitance of the coaxial capacitor CX will change linearly. Coaxial capacitor CX, capacitors C3, C4, C7, C8, C9 and inductor L1 form an oscillation circuit 3, capacitors C7, C8, C9 and coaxial capacitor CX are connected in parallel to one end of inductor L1, capacitors C7, C8, C9 and After the coaxial capacitor CX is connected in parallel, the other end is grounded; after the capacitor C3 and the capacitor C4 are connected in series, one end of the capacitor C3 is connected with the other end of the inductor L1, and the other end of the capacitor C4 is grounded. Therefore, a change in the capacitance of the coaxial capacitor CX causes a change in the oscillation frequency of the oscillation circuit 3 . the

The frequency signal generated by the oscillator circuit 3 is input into the push-pull amplifier circuit 1 through one end of the capacitor C2. The push-pull amplifier circuit 1 is composed of resistors R2-R5, diodes D1, D2 and capacitor C2; the emitter of transistor Q2 is connected to the collector of transistor Q1 through resistor R4 and resistor R5 in turn, and the base of transistor Q2 is connected through The diode D2 and the diode D3 are connected to the base of the transistor Q1, and the base of the transistor Q2 is connected to the collector of the transistor Q2 through the resistor R2, and the collector of the transistor Q2 is connected to the power supply through the diode D1 and the resistor R1, and the transistor Q1 The emitter of the capacitor is grounded; the other end of the capacitor C2 is connected to the base of the transistor Q2 through the resistor R3. The frequency signal amplified by the oscillating circuit 3 is output from one end of the capacitor C1 to the input end of the water content analyzer in crude oil through the common end of the resistor R4 and the resistor R5. the

In order to make the signal not distorted and have certain anti-interference performance, the design scheme of the stabilization circuit 2 can be as follows: it is composed of a transistor Q3, resistors R8-R13, and capacitors C6 and C11; the collector of the transistor Q3 is connected with the capacitor C5 C2, C3, and the common end of the inductance L1 are connected, the emitter of the transistor Q3 is connected with the common ends of the capacitors C3 and C4, the base of the transistor Q3 is connected with the collector of the transistor Q2 through the resistors R6 and R8; the resistor R11 and the capacitor After C6 is connected in parallel, one end is grounded, and the other end is connected to the base of transistor Q3; the collector of transistor Q3 is connected to the emitter of transistor Q3 through resistor R10, resistor R9, capacitor C11, resistor R13, and resistor R12 in sequence, of which capacitor C11 The common terminal of resistor R13 is grounded. the

Claims (6)

1. an online crude oil hangs down and contains water sensor, comprises sensor body and built-in circuit, and it is the ganged condenser CX of medium with the crude oil emulsion that the sensor body is one; It is characterized in that: built-in circuit is the electric capacity freq converting circuit; Described electric capacity freq converting circuit comprises an oscillatory circuit (3), is used for converting capacitance into frequency signal a push-pull amplifier circuit (1); This circuit amplifies frequency signal; The input end of its output termination water in oil analyzer, a signal stable circuit (2), this circuit guarantees oscillatory circuit (3) and push-pull amplifier circuit (1) steady operation.

2. the low water sensor that contains of online crude oil according to claim 1; It is characterized in that: described oscillatory circuit (3) is by capacitor C 3, C4, C7, C8, C9; Inductance L 1 is formed with ganged condenser CX, and an end links to each other other end ground connection after capacitor C 7, C8, C9 and the ganged condenser CX parallel connection after described capacitor C 7, C8, C9 and the ganged condenser CX parallel connection with inductance L 1 one ends; Capacitor C 3 is linked to each other capacitor C 4 other end ground connection with capacitor C 4 series connection backs with inductance L 1 other end by capacitor C 3 one ends.

3. the low water sensor that contains of online crude oil according to claim 1; It is characterized in that: described push-pull amplifier circuit (1) is made up of resistance R 2～R5, diode D1, D2 and capacitor C 2; The frequency signal that oscillatory circuit (3) produces is by the end input of capacitor C 2; Frequency signal after the amplification is exported by an end of capacitor C 1 through the common port of resistance R 4, resistance R 5; The other end of capacitor C 2 links to each other through the base stage of resistance R 3 with transistor Q2; The emitter of described transistor Q2 links to each other with the collector of transistor Q1 through resistance R 4, resistance R 5 successively, and the base stage of transistor Q2 links to each other with the base stage of transistor Q1 via diode D2, diode D3 successively, and the base stage of transistor Q2 links to each other with transistor Q2 collector via resistance R 2 simultaneously; Transistor Q2 collector links to each other with power supply through diode D1, resistance R 1, the grounded emitter of transistor Q1.

4. the low water sensor that contains of online crude oil according to claim 1; It is characterized in that: described signal stable circuit (2) is made up of a transistor Q3, resistance R 8～R13 and capacitor C 6, C11; The collector of transistor Q3 links to each other through the common port of capacitor C 5 with capacitor C 2, C3, inductance L 1; The emitter of transistor Q3 links to each other with the common port of capacitor C 3, C4, and the base stage of transistor Q3 links to each other with transistor Q2 collector through resistance R 6, R8, and the base stage of transistor Q3 is successively through resistance R 8; Resistance R 9, resistance R 10 links to each other with its collector; Resistance R 11 and capacitor C 6 parallel connection backs one end ground connection; One end links to each other with the base stage of transistor Q3; The collector of transistor Q3 links to each other with the emitter of transistor Q3 through resistance R 10, resistance R 9, capacitor C 11, resistance R 13, resistance R 12 successively, wherein capacitor C 11 resistance R 13 common end groundings.

5. online crude oil according to claim 1 is low to contain water sensor, and it is characterized in that: it has only two extension lines, power lead and signal wire conllinear.

6. online crude oil according to claim 1 is low to contain water sensor, it is characterized in that: the base stage of described oscillatory circuit (3) triode Q1 is connected to resistance R 7 and joins with ground.

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