CN106018870B - A kind of intelligent pipeline flow monitoring instrument - Google Patents

Abstract

The invention relates to an intelligent pipeline velocity monitor, which belongs to the field of fluid monitoring. The inner cylinder in the pipeline is divided into left and right chambers by partitions, the left chamber is equipped with a circuit board and the end is equipped with a left end cover; the left and right half shafts of the pin shaft are respectively covered with buffer springs and balance springs, and the left half shaft protrudes through the left end cover , The end is equipped with an exciter, and the right half shaft extends from the partition into the right cavity; the right end cover crimps two outer frames and at least one inner frame in the right cavity; the adjacent inner and outer frames and the inner frame are crimped. The metal substrate, the cantilever beam of the metal substrate and the piezoelectric chip are bonded to form a piezoelectric vibrator, and the other end of the cantilever beam is fixed on the right half shaft; one side of the outer frame and both sides of the inner frame are provided with limiting surfaces and sinks. Advantages and features: use the coupling effect to realize power generation and self-measurement of flow velocity synchronously, which can realize the true online monitoring of flow velocity; the monitor is arranged along the length of the pipeline, with simple structure, small radial scale, and easy to obtain the required energy through multiple piezoelectric vibrators; The piezoelectric vibrator has reasonable structure, large power generation and high reliability.

Description

An Intelligent Pipeline Velocity Monitor

technical field

The invention belongs to the technical field of pipeline fluid monitoring, and in particular relates to an intelligent pipeline flow velocity monitor.

Background technique

Due to natural corrosion, natural force majeure, and man-made theft, leakage events of long-distance pipelines for oil and natural gas and other fluids during use occur from time to time. Frequent pipeline leakage not only causes huge economic losses, but also affects the surrounding nature. The environment has caused serious pollution. In the past, regular manual inspections were often used for maintenance. However, due to the long laying distance of oil and gas pipelines and the fact that they are often located in inaccessible or inconvenient places, regular inspections are difficult to find leaks and maintain them in time. Therefore, various types have been proposed for pipeline leakage monitoring or anti-theft systems. Although some of the pipeline leakage or anti-theft monitoring and alarm methods proposed are relatively mature at the technical level, the application of the anti-theft monitoring system for long-distance pipelines in China is still in the preliminary stage and has not been widely used. One of the main reasons is that The power supply problem of the monitoring system has not been well resolved: 1) The method of laying cables is expensive and is easily cut off by criminals, which affects the normal operation of the monitoring system; 2) When using batteries for power supply, the use time is limited and needs to be replaced frequently. Once the battery is insufficient and not replaced in time, the remote transmission of monitoring information cannot be completed; 3) In recent years, in order to meet the self-power supply requirements of related wireless sensor monitoring systems, people have also proposed various forms of turbine-type miniature power generation devices. The biggest problem is that the structure is complex, the volume is relatively large, and it is not suitable for occasions with small diameter pipes. Some structures of power generation devices also have electromagnetic interference and other phenomena, which restricts their popularization and application. Therefore, in order to enable the oil and gas pipeline leakage and anti-theft system to be practically applied, the power supply problem still needs to be solved at first.

Contents of the invention

Aiming at the problems existing in the power supply of the existing pipeline fluid state monitoring system, the invention proposes an intelligent pipeline flow velocity monitor. The embodiment adopted by the present invention is: the inner wall of the pipeline is fixed with the inner tube through the rib plate, and the main frame is composed of the pipeline, the rib plate and the inner tube; There are guide holes and wiring holes on the partition; the circuit board with the transmitting unit is fixed by screws in the left cavity, and the left end cover is installed on the end by screws; the pin shaft shoulder divides the pin shaft into left half shaft and right half shaft The left and right half shafts are respectively covered with buffer springs and balance springs; the left half shaft protrudes from the left cavity through the center hole of the left end cover, and the end of the left half shaft is equipped with an exciter; the right half shaft extends from the guide hole of the partition The right cavity, the end of the right cavity is installed with a right end cover through screws, and the right end cover crimps two outer frames and at least one inner frame in the right cavity; between the outer frame and the adjacent inner frame, and between two adjacent inner frames Metal substrates are crimped between the inner frames. The metal cantilever beam on the metal substrate and the bonded piezoelectric chip constitute a piezoelectric vibrator. The other end of the metal cantilever beam is fixed on the right side by a nut, a short sleeve and a long sleeve. On the semi-axis; one side of the outer frame and both sides of the inner frame are provided with limiting surfaces and sinking grooves with the same shape, size and number; the sinking groove is used to accommodate the piezoelectric chip, and its plane size is larger than the piezoelectric chip and smaller than the metal Cantilever beam; the limiting surface is used to limit the deformation of the piezoelectric vibrator. The limiting surface is an arc surface and its reasonable curvature radius depends on the material and thickness of the metal substrate and piezoelectric wafer; the piezoelectric vibrators are connected to each other through wires After parallel connection, it is connected to the circuit board. Parallel connection means that the piezoelectric wafers are connected to each other through wires, and the metal substrates are connected to each other through wires.

During operation, that is, when fluid flows through the actuator, there will be an interaction between the fluid and the actuator. Under certain conditions, when the fluid flows through the actuator, two rows of vortices with opposite rotation directions and periodic shedding will be formed behind the actuator. The alternate shedding of the vortices will cause the fluid pressure to change alternately. The fluid pressure difference changes alternately, so that the exciter generates reciprocating vibration in the left and right directions. For the present invention, the left and right reciprocating vibrations of the exciter force the piezoelectric vibrator to produce bending deformation through the pin shaft, thereby converting mechanical energy into electrical energy; the generated electrical energy is transmitted to the energy conversion and storage circuit of the circuit board through wires, and supplies power to the signal transmitting unit; at the same time, The quantity of the voltage waveform generated by the piezoelectric vibrator is also extracted to characterize the fluid flow rate, and the fluid flow rate signal is emitted by the transmitting unit.

In the present invention, in order to enable the piezoelectric vibrator to be effectively excited, the monitor should meet the following requirements when the monitor works at the rated flow rate: the fluid force F _l on the pin shaft is equal to the difference between the balanced spring force F _p and the buffer spring force F _h , that is, F _l ＝F _p -F _h , the static deformation of the piezoelectric vibrator is zero, and the diameter of the actuator is D=(200～5000)μ/(ρv ₀ ), where D is the diameter of the actuator, ρ is Fluid density, μ is the fluid dynamic viscosity, v ₀ is the rated flow velocity of the pipeline.

In the present invention, the flow rate of the fluid in the pipeline is characterized by the number of voltage waveforms generated by the piezoelectric vibrator per unit time, that is, v=f _l D/S _i , where S _i is a coefficient related to the structure and fluid performance, and D is The diameter of the exciter, f _l is the vibration frequency caused by the fluid flowing through the exciter, that is, the number of voltage waveforms generated per unit time.

In the present invention, in order to improve the power generation capacity and reliability of the piezoelectric vibrator, the piezoelectric wafer is PZT4 of 0.2-0.3 mm, the metal substrate is beryllium bronze, and the thickness ratio of the metal substrate to the piezoelectric wafer is 1-2.5. At this time, the piezoelectric The power generating capacity of the vibrator is strong and the energy is relatively large; the energy ratio refers to the ratio of the electric energy generated by one bending deformation of the piezoelectric vibrator with different thickness ratios to the maximum value; for the present invention, the PZT4 and beryllium copper substrates are used For the piezoelectric vibrator, the reasonable radius of curvature of the limiting surface is Among them, α=h _m /h _p is the thickness ratio, and h _m and h _p are the thicknesses of the metal substrate and the piezoelectric wafer, respectively.

Advantages and features: use the coupling effect of the actuator and the fluid to realize power generation and automatic measurement of the flow rate synchronously, without external energy supply and sensors, and without electromagnetic interference, real-time online monitoring of the flow rate can be realized; the monitor is arranged along the length of the pipeline, The structure is simple, the radial scale is small, and it is easy to obtain the required energy by using multiple piezoelectric vibrators; the piezoelectric vibrator has a reasonable structure, the deformation is limited by the limit plane, and the deformation curvature of each point is equal, so the power generation is large and the reliability is high.

Description of drawings

Fig. 1 is the structural representation of monitor in a preferred embodiment of the present invention;

Fig. 2 is the left view of Fig. 1;

Fig. 3 is an enlarged view of part I of Fig. 1;

Fig. 4 is A-A sectional view of Fig. 1;

Fig. 5 is a schematic structural view of the main frame in a preferred embodiment of the present invention;

Fig. 6 is a schematic structural view of an outer frame in a preferred embodiment of the present invention;

Fig. 7 is the right view of Fig. 6;

Fig. 8 is a schematic structural view of an inner frame in a preferred embodiment of the present invention;

Fig. 9 is a right side view of Fig. 8 .

Detailed ways

The inner cylinder c is fixed on the inner wall of the pipeline a through the rib b, and the pipeline a, the rib b and the inner cylinder c form the main frame K; the inner side of the cylinder wall c1 of the inner cylinder c is provided with a partition c2, and the partition c2 separates the inner cylinder c is divided into a left chamber c3 and a right chamber c4; the partition c2 is provided with a guide hole c5 and a wiring hole c6; a circuit board with a transmitting unit P is fixed in the left chamber c3 by screws, and a left end cover is installed on the end by screws k; the shoulder m1 on the pin shaft m divides the pin shaft m into a left half shaft m2 and a right half shaft m3, and the left half shaft m2 and the right half shaft m3 are respectively covered with a buffer spring j1 and a balance spring j2; the left half shaft m2 Extrude from the left cavity c3 through the center hole of the left end cover k, and the exciter n is installed at the end of the left semi-axis m2; The right end cover g is installed through screws, and the right end cover g crimps two outer frames e and at least one inner frame f in the right cavity c4; between the outer frame e and the adjacent inner frame f, and between two adjacent inner frames The metal substrate h1 is crimped between the inner frames f of the metal substrate h1, and the metal cantilever beam h11 on the metal substrate h1 and the bonded piezoelectric chip h2 form a piezoelectric vibrator h. The other end of the metal cantilever beam h11 is passed through a nut p, a short The shaft sleeve i' and the long shaft sleeve i are fixed on the right half shaft m3; one side of the outer frame e and both sides of the inner frame f are provided with a limit surface M and a sinker C with the same shape and size and the same number; the sinker C is used to accommodate the piezoelectric wafer h2, and its plane size is larger than the piezoelectric wafer h2 and smaller than the metal cantilever beam h11; the limiting surface M is used to limit the deformation of the piezoelectric vibrator h, and the limiting surface M is an arc surface and its reasonable The radius of curvature depends on the material and thickness of the metal substrate h1 and the piezoelectric chip h2; the piezoelectric vibrators h are connected to each other through wires in parallel and then connected to the circuit board d. Parallel connection means that the piezoelectric chips h2 are connected to each other through wires Connection, the metal substrates h1 are connected to each other through wires.

When working, that is, when fluid flows through the actuator n, there will be interaction between the fluid and the actuator n. Under certain conditions, when the fluid flows through the actuator n, two rows of vortices with opposite rotation directions and periodic shedding will be formed behind the actuator n. The alternate shedding of the vortices will cause the fluid pressure to change alternately, even if the actuator n The fluid pressure difference on both sides changes alternately, so that the exciter n generates reciprocating vibration in the left and right directions. For the present invention, the left and right reciprocating vibration of the exciter n forces the piezoelectric vibrator h to produce bending deformation through the pin shaft m, thereby converting mechanical energy into electrical energy; the generated electrical energy is transmitted to the energy conversion and storage circuit of the circuit board d through wires, which is used for signal transmission The unit P supplies power; at the same time, the number of voltage waveforms generated by the piezoelectric vibrator h is also extracted to characterize the fluid flow rate, and the fluid flow rate signal is emitted by the transmitting unit P.

In the present invention, in order to enable the piezoelectric vibrator h to be effectively excited, when the monitor works at the rated flow rate v ₀ , it should satisfy: the fluid force F _l on the pin shaft m is equal to the balance spring force F _p and the buffer spring force The difference between F _h , that is, F _l = F _p -F _h , the static deformation of the piezoelectric vibrator h is zero, and the diameter of the actuator n is D=(200～5000)μ/(ρv ₀ ), where D is the diameter of the actuator, ρ is the fluid density, and μ is the fluid dynamic viscosity.

In the present invention, the flow rate of the fluid in the pipeline is characterized by the number of voltage waveforms generated by the piezoelectric vibrator per unit time, that is, v=f _l D/S _i , where S _i is a coefficient related to the structure and fluid performance, and D is The diameter of the exciter, f _l is the vibration frequency caused by the fluid flowing through the exciter, that is, the number of voltage waveforms generated per unit time.

In the present invention, in order to improve the power generation capacity and reliability of the piezoelectric vibrator h, the piezoelectric wafer h2 is PZT4 of 0.2 to 0.3 mm, the metal substrate h1 is beryllium bronze, and the ratio of the thickness of the metal substrate h1 to the piezoelectric wafer h2 is 1 ~2.5, at this time, the piezoelectric vibrator h has strong power generation capacity and relatively large energy; the energy ratio refers to the ratio of the electric energy generated by one bending deformation of the piezoelectric vibrator h with different thickness ratios to the maximum value; for this The piezoelectric vibrator h composed of PZT4 and beryllium copper substrate is invented, and the reasonable radius of curvature of the limiting surface M is Where α=h _m /h _p is the thickness ratio, h _m and h _p are the thicknesses of the metal substrate h1 and the piezoelectric wafer h2 respectively.

Obviously, the present invention utilizes the coupling effect of the exciter and the fluid to generate electricity and realize the automatic measurement of the flow velocity, without external energy supply and sensors, without electromagnetic interference, and can realize real-time online monitoring of the flow velocity in a true sense; the monitor is arranged along the length of the pipeline, and the structure Simple, small radial scale, easy to obtain the required energy by using multiple piezoelectric vibrators; the piezoelectric vibrator has a reasonable structure, the deformation is limited by the limit plane, and the deformation curvature of each point is equal, so the power generation is large and the reliability is high.

Claims (1)

1. a kind of intelligent pipeline flow monitoring instrument, it is characterised in that：Inner wall of the pipe is fixed with inner cylinder through gusset, be equipped with pilot hole and Inner cylinder is separated into left chamber and right chamber by the partition board in cable hole；Circuit board, the end peace of transmitter unit are provided with inside left chamber Equipped with left end cap；Axis pin is divided into left half axle and right axle shaft by the axis pin shaft shoulder, and buffer spring and balance are cased with respectively on the semiaxis of left and right Spring；Left half axle is through left end cap centre bore from left chamber is stretched out, end is equipped with driver；Right axle shaft stretches into the right side from partition board pilot hole Chamber, right chamber end are equipped with right end cap, and two outline borders and at least one inside casing are crimped in right chamber by right end cap；Outline border and adjacent Inside casing between and two adjacent inside casings between be all crimped with metal substrate, the metal cantilever beams on metal substrate with institute it is be bonded Piezoelectric chip constitute piezoelectric vibrator, the other end of metal cantilever beams is fixed on right axle shaft；Outline border side and inside casing both sides are all Equipped with shape scale and the identical confined planes of quantity and deep gouge, deep gouge planar dimension is more than piezoelectric chip, is less than metal cantilever beams, Confined planes are arc surface；PZT4 that piezoelectric chip is 0.2~0.3mm, metal substrate are beryllium-bronze, metal substrate and piezoelectric chip Thickness ratio be 1~2.5, the reasonable radius of curvature of confined planes isWherein α =h_m/h_pFor thickness ratio, h_mAnd h_pRespectively metal substrate and piezoelectric chip thickness；Between each piezoelectric vibrator mutually simultaneously through conducting wire It is connect again with circuit board after connection；Fluid force suffered by nominal flow rate lower bearing pin be equal to suffered equilibrium bomb spring force and buffering elastic spring force it Difference, the quiet deflection of piezoelectric vibrator are zero and driver a diameter of D=(200~5000) μ/(ρ v₀), measured fluids within pipes Flow velocity be v=f_lD/S_t, ρ is fluid density in formula, μ is fluid kinematic viscosity, S_tFor with structure and the relevant system of fluid property Number, f_lCaused vibration frequency when overdriving device for fluid stream, v₀For nominal flow rate.