RU93530U1 - BIDIRECTIONAL PIPE PISTON CHECK INSTALLATION - Google Patents

Abstract

 1. Bidirectional pipe-piston calibration installation, which is a pipeline section with a calibrated section bounded by detectors, inside which a ball piston moves, connected by a gateway to the starting and receiving chambers and a device for changing the direction of fluid movement located between the cameras, characterized in that the calibrated section is made rectilinear! 2. Pipe-piston calibration apparatus according to claim 1, characterized in that the receiving and launching chambers are arranged vertically or obliquely. ! 3. Pipe-piston calibration unit according to any one of claims 1 and 2, characterized in that the receiving and launching chambers are located in the same plane with the calibrated section. ! 4. Pipe-piston calibration apparatus according to any one of claims 1 and 2, characterized in that a four-way valve of a Z-shaped design is used as a device for changing the direction of fluid movement. ! 5. Pipe-piston calibration apparatus according to claim 3, characterized in that a four-way valve of a Z-shaped design is used as a device for changing the direction of fluid movement. ! 6. Pipe-piston calibration unit according to any one of claims 1, 2, 5, characterized in that the electromechanical type detectors are used. ! 7. Pipe-piston calibration unit according to any one of claims 1, 2, 5, characterized in that two detectors are installed at the beginning and end of the calibrated section. ! 8. Pipe-piston calibration apparatus according to any one of claims 1, 2, 5, characterized in that it additionally contains sensors for temperature and pressure of the liquid. ! 9. Pipe-piston calibration installation according to any one of claims 1, 2, 5, characterized in that it is made

Description

The utility model relates to measuring equipment, namely, to piston-testing systems, and can be used in the oil and gas industry.

The main means used for checking turbine and other flow converters (TPR) at oil metering stations (UUN) are pipe-piston calibration units (TPU).

Compared with other means of verification, TPU have great advantages:

- the ability to verify the transducers at the place of operation during the measurement under operating conditions;

- complete sealing of the verification process;

- the possibility of checking TPR at high costs - up to 10.000 m ³ / h;

- independence of the metrological characteristics of TPU from the type, viscosity of the liquid and operating conditions;

- the ability to fully automate the verification process.

Only thanks to the use of TPU it became possible to verify turbine meters for commercial metering of oil and oil products at the place of operation. Currently, at the enterprises of the oil industry, for testing meters for various purposes, TPUs with a throughput of 100 to 4000 m ³ / h, both domestic and foreign manufacturers, are used.

TPU is a section of the pipeline, assembled from pipes and bends, in which a ball piston moves, carried away by the pressure of the liquid (oil), the passage of which is recorded by sensors-detectors. The area bounded by the detectors and called the calibrated area is made of pipes and bends calibrated by the inner diameter. In most cases, the inner surface of the calibrated area is thoroughly cleaned and coated with synthetic resins to protect it from corrosion and reduce friction when the piston moves. When the piston passes through the first detector, its signal starts the counting of pulses from the tested TPR. When the piston reaches the second detector, its signal stops counting pulses. After passing the calibrated section, the piston must be returned. According to the meter reading and the volume of the calibrated TPU section, the conversion coefficient and other metrological characteristics of the TPD are determined.

According to the piston return method, TPUs are divided into two types: unidirectional and bidirectional. In unidirectional TPU, the piston always moves in one direction - from the beginning to the end of the calibrated section. For this, between the beginning and the end of the calibrated section there is a device for starting and receiving the piston. With the help of this device, the piston is launched into the calibrated section, and, after passing through the latter, it again enters this device. In bidirectional TPU, the piston moves along the calibrated section in both directions (it moves alternately: in one direction or in the other direction). After each piston passes through the calibrated section, the direction of fluid movement changes with the help of a device for changing the direction of fluid movement (flow switch).

As the closest analogue (prototype) in terms of essential features for the claimed utility model, the well-known (Fig. 2, p. 4 "Manual of Petroleum Measurement Standards Chapter 4-Proving Systems. Section 2-Conventional pipe Provers. First EDITION, OCTOBER 1998 American Petroleum Institute 1220 L Street, Northwest, Washington, DC 20005) a bidirectional TPU design that is a pipe section with a calibrated section bounded by detectors, inside which a ball piston moves, connected by a gateway to the launch and receiving chambers and a device for and Menenius direction of fluid flow. The reasons that impede the achievement of the following technical result when using the well-known TPU design include the fact that in order to reduce the dimensions of the installation, the calibrated section of the TPU is made in the form of a loop consisting of pipes and bends.

The problem to which the claimed utility model is directed is to modernize the testing equipment of the oil and gas industry.

The main technical result that can be obtained using this utility model is to increase the accuracy and reliability of the measurements.

The specified technical result is achieved due to the fact that in the known bidirectional pipe-piston calibration unit, which is a pipe section with a calibrated section bounded by detectors, inside which a ball piston moves, connected by a gateway to the starting and receiving chambers and a device for changing the direction of fluid movement located between the chambers the plot is straightforward.

The conversion coefficient and other metrological characteristics of TPR are determined by the meter reading and the volume of the calibrated TPU section. The accuracy of the measurements is increased by maintaining the stability of fluid movement along the straight section of the calibrated pipe and maintaining the stability of the hydraulic resistance in the calibrated section of the TPU.

The volume of oil passed in the inventive utility model will be considered as the passage of the ball piston in a straight line, in contrast to existing designs, when the ball piston goes in circles. Observations showed that the ball piston moves smoothly and without extraneous noise along the straight section of the pipe, while when bending in the bends of the curved calibrated section, its uneven movement and extraneous noise (creaking) are clearly audible, and a flow rate is observed in the flowmeter. That is, in the case when the calibrated section is made straightforward, the hydraulic resistance is more stable.

Pipe-piston installation is a standard measuring instrument, therefore repeatability of measurements is a very important parameter. Despite the fact that the required repeatability of +/- 0.02% is ensured by other TPU configurations, a TPU configuration with a direct calibrated section provides higher characteristics of repeatability and overall measurement accuracy, especially when calibrating "inertialess" flow meters (ultrasonic), and also when determining the volume of the calibrated TPU section for water at low costs. In addition, flow stability increases the life of the epoxy coating of the pipe.

An additional technical result is the reduction of TPU design complexity: when constructing a calibrated section of a utility model, only a straight pipe must be selected, in contrast to the prototype, when a special selection of several positions of calibrated pipes and bends is required. The implementation of the utility model reduces the complexity of the technological process of manufacturing TPU due to the lack of the need to ensure accurate alignment of the inner diameters of the pipe flanges and bends of the calibrated section in the prototype.

To increase the reliability of measurements, two detectors can be installed at the beginning and end of the calibrated section, of which simple, reliable and accurate electromechanical type detectors are most widely used.

In addition to the detectors, TPU can have sensors signaling the position of the piston and the stages of TPU operation (piston start, passage through the detectors, arrival in the chamber, etc.). The presence of such sensors facilitates the management of TPU. All TPUs have instruments (sensors) for measuring the temperature of walls, liquids and pressure at the inlet and outlet of the installation. To ensure full automation of the verification process, TPUs are equipped with sensors for temperature and liquid pressure.

In special cases of TPU execution, the receiving and launching chambers can be located vertically or inclined, as well as in the same plane with the calibrated section.

There are many designs of devices for changing the direction of fluid movement (flow switch), among which one can distinguish a four-way valve plug or Z-shaped design.

TPU can be made stationary or mobile (by car or trailer).

Figure 1, 2 - views in isometric stationary TPU bidirectional action with a four-way valve;

Figure 3 - device for changing the direction of movement of the fluid of 2 types with a transverse section:

a) four-way crane Z-shaped design;

b) four-way plug valve;

Figure 4 - section of the interaction of the detector TPU with a ball piston in the context;

5 is a kinematic diagram of the transmission of motion from the detector to the contacts of the microswitch;

6 is a section of the interaction of the detector TPU with a ball piston in the context to determine the main parameters of the TPU.

Information confirming the feasibility of implementing a utility model with obtaining the above technical result is given on the example of a specific bi-directional TPU device.

The installation contains (Fig. 1, 2) a calibrated section 1 with detectors 2, inside of which a ball piston 3 moves, a start and a receiving chamber 4 and a device installed between them for changing the direction of fluid movement in the form of a four-way valve 5. Connected at the ends of the calibrated section the receiving and launch chambers are inclined by the gateway, have the same design and are a pipe segment having a diameter greater than the diameter of the calibrated section. At the time of verification of the TPU meters, they are connected to the UUN with hinged (flexible) pipelines.

Installation works as follows.

To verify the meter (flow transducer), a piston is introduced into the pipeline in front of the calibrated section, which completely covers the cross section and moves with the liquid at the same speed. When the piston passes through the first detector, its signal starts the counting of pulses from the verified TPR. When the piston reaches the second detector, its signal stops counting pulses. According to the meter reading and the volume of the calibrated TPU section, the conversion coefficient and other metrological characteristics of TPU are determined. After exiting the calibrated section, the ball piston enters one of the chambers and is in it in an upward flow until the direction of movement is reversed and the piston is again involved in the calibrated section.

To change the direction of fluid movement, a four-way Z-shaped valve is used (Fig. 3a), in a cylindrical body 6 of which there is a Z-shaped switch 7 that can rotate around a vertical axis and sealed around the periphery of the sleeve 8. The crane is rotated using a hydraulic cylinder. The flow switching scheme is clear from the figure. To reduce the friction forces and prevent the cuff from breaking when the crane is turned, the cuff is made in the form of a tube made of polyurethane, the inner cavity of which is filled with oil. After turning the valve, pressure is applied to the cuff, the tube expands and the valve is sealed. Before the next turn, the pressure inside the cuff decreases, its cross section decreases and friction is excluded when the crane is turned.

In the described TPU, a piston made in the form of a hollow ball of polyurethane is used. The inner cavity of the ball is filled with liquid, for which it is equipped with a valve embedded in the wall.

The material and design of the piston meets the following requirements:

- resistance to the measured environment;

- high mechanical strength and abrasion resistance;

- high elasticity;

- resistance to temperature from minus 5 to + 50 ° C;

- low coefficient of friction;

- the design of the piston should allow its diameter to be changed by pumping liquid under excessive pressure.

Elastomers such as polyurethanes satisfy these requirements. The wall thickness of the piston depends on the internal diameter of the calibrated section and is 25-50 mm or more, depending on the internal diameter of the calibrated section of TPU. During TPU operation, the piston diameter should be larger than the inner diameter of the pipes of the calibrated section (the so-called “interference fit”) in order to prevent fluid leakage between the piston and pipe walls and the piston lagging from the fluid.

To obtain a signal during the passage of the piston, various types of sensors are used. The most widespread simple, reliable and accurate detectors of the electromechanical type (figure 4). The principle of operation of such a detector is that the ball piston 3 acts on the rounded end of the rod 9, the lower end of which enters the pipe by 5-10 mm, and the latter acts through the lever system on the contacts of the microswitch 10 (figure 5). The contacts switch a circuit through which the necessary signal is supplied to start or end the counting of pulses of the TPR signal. The main requirement for the detectors is their high accuracy, i.e. the ability to record the passage of the piston at the same point with a slight discrepancy. The magnitude of this discrepancy can be expressed by the error of the detectors. The length of the calibrated section, its dimensions and metal consumption depend on the error of the detectors. The smaller the error of the detectors, the smaller the length of the calibrated section may be.

The secondary device (controller) TPU generally provides:

- management of TPU executive bodies with control, indication of operations and blocking of emergency situations;

- automatic measurement of parameters (the number of pulses of the output TPR signal, temperature, pressure);

- indication of fluid flow;

- automatic processing and recording of the results of verification of TPR or meters;

- manual entry of constant parameters.

The actual error of TPU is not the same and varies from 0.05 to 0.1% depending on the quality of the pipes (constancy of diameter, difference, ovality), coating, piston and verification method.

The definition of the main parameters of TPU is carried out according to the following methodology (figure 5):

1) The internal diameter of the calibrated section is determined based on the maximum flow rate Qmax and the speed of the piston 3. The speed of the piston can be taken 3 m / s for all types of TPU.

Then

where Qmax is in m ³ / s.

2) The minimum length of the calibrated section is determined

Lmin = ΔL · 10000,

where ΔL is the error of the detector, reduced to the piston stroke

D is the diameter of the calibrated section;

d is the diameter of the head of the detector rod;

l ₁ - the distance by which the rod 9 of the detector in the output position.

ΔL is determined experimentally during the development of TPU or is determined by calculation through the error of the detector along its rod Δl. The experimental determination of Δl is much simpler than the determination of ΔL.

where D is the diameter of the calibrated section;

d is the diameter of the head of the detector rod;

l ₁ - the distance at which the detector rod protrudes in the output position ;; l ₂ = l ₁ -Δl

3. The volume of the calibrated section is determined

Vk = 0.785D ² L,

4. The error of counting the number of pulses from the TPR is checked.

where ΔN is the absolute error of the secondary TPU device, in fractions of a pulse;

Nmin - the minimum number of pulses from the verified TPD, corresponding to the volume of the calibrated TPU section, pulses.

where K is the conversion coefficient of the TPR, which will be verified on this TPU (the minimum value is taken).

The above information indicates the fulfillment of the following conditions when implementing the claimed utility model:

- the tool embodying the device in its implementation, is intended for use in the oil and gas industry;

- for the claimed device in the form described in the independent claim, the possibility of its implementation using the means and methods described in the application and known prior to the priority date of the application is confirmed;

- the tool embodying the claimed utility model in its implementation, is able to ensure the achievement of the above applicant technical result.

Claims (9)

1. Bidirectional tube-piston calibration installation, which is a pipeline section with a calibrated section bounded by detectors, inside which a ball piston moves, connected by a gateway to the starting and receiving chambers and a device for changing the direction of fluid movement located between the cameras, characterized in that the calibrated section is made rectilinear 2. Pipe-piston calibration apparatus according to claim 1, characterized in that the receiving and launching chambers are arranged vertically or obliquely. 3. Pipe-piston calibration unit according to any one of claims 1 and 2, characterized in that the receiving and launching chambers are located in the same plane with the calibrated section. 4. Pipe-piston calibration apparatus according to any one of claims 1 and 2, characterized in that a four-way valve of a Z-shaped design is used as a device for changing the direction of fluid movement. 5. Pipe-piston calibration apparatus according to claim 3, characterized in that a four-way valve of a Z-shaped design is used as a device for changing the direction of fluid movement. 6. Pipe-piston calibration unit according to any one of claims 1, 2, 5, characterized in that the electromechanical type detectors are used. 7. Pipe-piston calibration unit according to any one of claims 1, 2, 5, characterized in that two detectors are installed at the beginning and end of the calibrated section. 8. Pipe-piston calibration apparatus according to any one of claims 1, 2, 5, characterized in that it additionally contains sensors for temperature and pressure of the liquid. 9. Pipe-piston calibration unit according to any one of claims 1, 2, 5, characterized in that it is made stationary or mobile.