RU2713105C1 - Apparatus for calibrating gas counters in a closed circuit at high pressure - Google Patents

Abstract

FIELD: test equipment.

SUBSTANCE: invention relates to closed cycle testing unit for calibration of gas meters at high pressure. Proposed plant comprises high pressure flow circuit, as well as working medium flow generator, for example, turbine unit and air blower system. Besides, a temperature control system is provided, for example, a heat-stabilizing chamber, or a cooler connected during operation with a circuit, as well as a control unit for feed (404) of the working medium. Besides, provision is made for system (405) of reference counters with possibility of connection in process of operation with said closed circuit (401), system for injecting working medium (407), which creates excess pressure in pipeline system, as well as system of high pressure cylinders (408, 508), operating with different gases, with possibility of connection in process of operation with test installation circuit.

EFFECT: disclosed is an apparatus for calibrating gas counters in a closed circuit at high pressure.

8 cl, 2 dwg

Description

The invention relates to the field of installations for calibrating gas flow meters in a closed loop at high pressure and to a method of operating the installation.

Gas flow meter manufacturers often need to test new gas flow meter designs to verify or confirm accuracy, quality, etc. Basically, manufacturers are able to host flowmeter testing using liquids. Fluid test facilities can be created without undue expense or time. It’s not so easy to create gas test installations. Thus, gas flow meter manufacturers, as a rule, need to go to test facilities and incur significant costs in order to use the test center. This process is time consuming and time consuming. Manufacturers now have to wait a few weeks or months before they can test new designs and get test results for new designs.

There are three main types of gas testing facilities.

The first type of plants described in WO2005 / 005938 A1 is units with a purge system. In the purge system, the compressor draws air from the atmosphere and compresses it in the tank. When the pressure in the reservoir reaches the pressure required for testing, air is discharged from the reservoir and passes through a reference meter and the instrument under test. Then the air is vented back into the atmosphere. The reference and test meter measures the gas flow when it passes through the tank back into the atmosphere. The readings of the measurements of the reference counter are used to calibrate the checked counter. The known purge system has a short period of operation, is expensive, inefficient and extremely noisy.

WO 2005/005938 A1 describes a different type of installation. It is a recirculation gas circuit. This test setup uses a recirculation gas circuit. This research facility includes a gas circuit, a compressor, a cooler, sound nozzles and sections for the devices under test. The compressor circulates the gas through the gas circuit at the desired flow rate. The compressor adds heat to the gas in the gas circuit during its circulation. The cooler cools the gas in the gas circuit to the desired temperature. The meter under test, together with one or more sound nozzles, measures the gas flow rate. Sound nozzles are the reference counters for the tested counters. The measurements made by the checked meter are compared with the measurements made with the help of sound nozzles to check the accuracy of the meter being checked or to calibrate the checked device. This very large research facility is extremely costly and energy intensive to operate. Existing research facilities cannot be successfully installed and put into operation in many companies due to their size, cost and energy consumption.

The third type according to the category of patent is disclosed in the following analogues: WO 2005/005938 A1, US 4590790 A, US 20050160784 A1, GB 402954 A and WO 2000058696 A1. This type combines test installations consisting of a closed flow circuit, discharge system, temperature control system, reference meter system, meter test system. A reference meter system measures the properties of the gas circulating through a closed flow loop. The meter test system also measures the properties of the gas circulating through the flow circuit. The readings of the reference meter system are compared with the readings of the instrument test system for further calibration of the instrument under test. This third type has several advantages over types 1 and 2. If necessary, the test setup can operate for several hours, while the purge systems have time limits. The discharge system in the test setup can also be smaller than the compressor in the purge system because the pressure system does not require a lot of pressure. The test installation does not need large tanks for storing gas under pressure and in the discharge of gas into the atmosphere. Therefore, this helps to avoid problems associated with noise that occurs in purge systems. The test facility is smaller than the research facility according to type 2. The test facility can be located in the building, or even in the corner of the building, while the research facility of type 2 is large. The test setup is predominantly inexpensive and efficient in operation, and can also be placed inside the building. Developers can then retrieve modification data and thus test on-site flowmeters. This saves time and money when developing new products.

However, a serious drawback of this type of installation is the location of the turbine engine of the injection system inside a closed circuit, which leads to significant heating of the working medium (gas) and the need for complex, high-performance and energy-intensive solutions to ensure temperature stability (cooling) and, as a consequence, explosion protection of this engine in the case of the use of combustible gases as a working medium. Another disadvantage of such installations is the complexity or inability to change the type of gas (working medium) in a closed loop, which causes problems if it is necessary to test meters (gas flow meters) for a particular type of gas.

Therefore, the objective of the invention is to develop such a typical test installation, which would be addressed by these disadvantages.

This problem is solved using the features described in paragraphs 1 and 9 of the claims.

This shows that the invention is carried out in the case when the test setup for calibrating gas meters works in a closed cycle at high pressure and contains the following functionally interconnected components:

- closed loop high pressure flow,

- a medium flow generator, for example, a turbine unit or a blower system made on a hydraulic actuator, with the ability to generate a high flow rate of various gases under high pressure inside a closed loop of the test setup,

- temperature control system, for example, a thermostabilizing chamber, a cooler connected during operation with a circuit,

- control unit for supplying a working medium at low volumetric flow rates,

- a system of reference counters with the ability to connect during operation with the specified closed loop,

- a system of verified meters with the ability to connect during operation with the circuit,

- a system for pumping a working medium that creates excess pressure in the pipeline system,

- a system of high-pressure cylinders with various gases with the possibility of connection during operation with the circuit of the test installation and

- a filter that purifies the medium circulating through the circuit.

The system for pumping the working medium into the closed circuit of the installation supplies the required working medium until the required pressure is reached. Thus, the system operates in a closed loop. When you turn on the turbine of the generator flow of the working fluid in the pipeline path of the closed loop of the installation creates a flow of the working fluid. The thermostabilizing chamber receives the flow of the working medium and controls its temperature. The systems of reference and verified meters measure the flow rate of the working medium circulating through the installation’s pipeline path. The error is calculated by comparing the volumes of the working medium under standard conditions, measured by the calibrated and reference meters.

Closed loop installation for calibrating gas pressure meters can be compact and efficient. The installation allows flowmeter manufacturers to receive prompt feedback on changes in the design of gas flow meters necessary in some cases. This can save time and money in developing new products. The installation also uses much less electricity than systems with a recirculation gas circuit, which makes it more cost-effective.

Other suitable and preferred embodiments of the invention are disclosed in the dependent claims.

A suitable embodiment of the invention provides that the system of verified meters is placed after the system of reference meters in the direction of flow; while the pipeline of the high pressure circuit is equipped with an emergency gas removal device from the circuit with a gas indicator. Damping anti-vibration inserts are installed between sections of the high pressure circuit pipeline. Further, a vacuum compressor is provided, which ensures the removal of gas residues from the closed high pressure circuit, as well as an inert gas unit connected to the pipeline of the high pressure circuit.

Another preferred embodiment of the invention provides:

- an electric motor located outside the closed circuit of the flow and driving a hydraulic motor with the help of a hydraulic pump, which is located inside the closed circuit of the medium;

- a turbine located inside a closed circuit, driven by a hydraulic motor and designed to create and control the gas flow rate in a closed installation pipeline system;

- an additional closed loop of the hydraulic drive of the fluid flow generator, equipped with an electric motor, a hydraulic pump, a cooler and a hydraulic motor rotating a turbine,

Several examples of the invention are shown schematically in the drawing and are explained in more detail below. The drawings show:

FIG. 1 Block diagram of a closed loop installation for calibrating pressure gas meters

FIG. 2 Functional diagram of a closed loop installation for calibrating gas pressure meters.

In FIG. 1 - 2 and the following description provides specific examples of the invention for training specialists in this field to implement and the best use of this invention. In order to explain the basic principles of the present invention, some generally accepted aspects of the invention have been simplified or omitted. Those skilled in the art will understand the variations set forth in the examples falling within the scope of this invention. Specialists in the art will understand the features set forth below, which can be combined in various ways, to form many variations of the present invention. As a result, the invention is not limited to the specific examples set forth below, but only to the claims of the claims and their equivalents.

FIG. 1 illustrates a closed loop installation 400 for calibrating gas pressure meters as an example of the invention.

FIG. 2 illustrates a test rig 500 in an embodiment of the invention.

Proposed according to the invention, the installation 400, 500 includes:

- closed loop high pressure stream 401, 501 with the ability to contain gas under pressure,

- a medium flow generator (turbine unit, blower system) 402, 502, made on a hydraulic actuator with the ability to generate a high flow rate of various gases under high pressure inside the closed loop of the installation,

- a temperature control system (thermostabilizing chamber, cooler) 403, 503 connected to the specified closed loop, and configured to control the temperature of said compressed gas,

- control unit for supplying a working medium at low volumetric flows 404, 504,

- a system of reference meters (reference line) 405, 505, connected to the specified closed loop and configured to measure the flow rate of the specified compressed gas,

- a system of verified meters (working line) 406, 506, connected to the specified closed loop and configured to connect the tested meter to measure the flow rate of the specified compressed gas,

- a system for pumping a working medium 407, 507, designed to create excess pressure in the pipeline system (closed loop) of the installation, with the possibility of pumping various gases into the installation system until the required pressure is reached,

- a system of high-pressure cylinders 408, 508 with various gases, which allows to supply various gases under high pressure in a closed loop of the test setup,

a vacuum compressor 413, 513 configured to remove residual air, various gases and moisture from a closed loop of the test setup, and

- a filter 411, 511 configured to remove contaminants from the stream. circulating in a closed loop test facility and preventing pollution of the reference meters.

The following definitions may help to understand the invention.

The flow loop 401, 501 includes any pipeline or closed structure containing gas.

The medium flow generator (turbine unit, blower system) 402, 502 is designed to generate a high flow rate of the specified gas under high pressure inside the closed loop 401, 501 of unit 400, 500. In this case, the medium flow generator is characterized by the following features:

- the presence of an electric motor 516 located outside the closed loop of the flow 401, 501 and driving a hydraulic motor 519 with the help of a hydraulic pump 517, which is located inside the closed loop of the medium 401, 501,

- the presence of an additional closed circuit 525 with a hydraulic working fluid, with the help of which the transmission of torque (motion) from an electric motor located outside the high pressure flow path 401, 501 to a turbine located inside the high pressure flow path 401, 501 is carried out,

- the presence of a turbine 520 located inside the closed loop of the high pressure stream 401, 501 and driven by a hydraulic motor 519; a turbine (520) is designed to control the flow of gas in a closed piping system of the installation; when you turn on the turbine 520 in the pipeline path of the installation creates a flow of the working medium.

The main advantages of this fluid flow generator 402, 502 are:

- placement of the electric motor 516 outside the working (explosive) environment, which, in contrast to the known solutions, completely removes the problem of ensuring explosion protection and explosion safety of equipment;

- the lack of heating of the working medium from the electric motor 516,

- a significant reduction in the energy spent on cooling the working environment,

- the presence of a hydraulic fluid cooler 518, providing an even higher level of thermal stabilization inside a closed loop.

The temperature control system (thermostabilizing chamber, cooler) 403, 503 is designed to cool the working medium (gas under pressure) and maintain the gas temperature at a constant level. The thermostabilizing chamber 403, 503 receives the flow of the working medium and controls (regulates) its temperature.

The unit for regulating the supply of a working medium at low volumetric flows 404, 504 is characterized by the presence of parallel lines of sound nozzles. Sound nozzles provide high stability of the flow of the working medium at its low costs.

The control unit for supplying a working medium is also characterized by the presence of a shut-off valve system, with the help of which switching and regulation of the flow rate range are carried out.

The system of reference meters (reference line) 405, 505 consists of reference meters, absolute pressure sensors and temperature sensors, the data from which are transmitted to the control system 414, 514. To convert the meter readings from operating conditions to standard conditions, the readings of the absolute pressure sensor and sensor are used temperature.

The system of verified meters (working line) 406, 506 consists of a telescopic compensator 415, 515, a verified meter, an absolute pressure sensor and a temperature sensor, the data from which are transmitted to the control system 414, 514. The telescopic compensator 415, 515 allows hermetically fix the verified meter on the working line. To convert the meter readings from operating conditions to standard conditions, the readings of the absolute pressure sensor and temperature sensor are used.

The system of verified meters (working line) 406, 506 is necessary for testing (calibration, verification) of the meter. It consists of a test device configured to test with the specified gas, and an interface device for connecting the test meter along the axis of the measuring line with the flow circuit 401, 501. The system of verified meters (work line) 406, 506 is connected to the specified closed loop 401, 501 and configured to connect a test meter to measure the flow rate of the specified compressed gas. The system 406, 506 is characterized by the presence of a number of working sections connected in parallel, in each of which it is possible to put a test (calibrated, verified) meter (gas flow meter). Each of these working sections is designed for a specific flow range.

Installation 400, 500 differs in that the system of verified meters 406, 506 is installed in the direction of flow after the system of reference meters 405,505, which eliminates the possibility of contaminants from the verified meters in the reference.

The device under test and one or more reference meters measure the flow rate of gas circulating in the installation’s pipeline path. The control system 414, 514 compares the readings of measurements obtained from the reference counters with the readings of measurements received from the devices under test, to verify the accuracy of the device under test or to calibrate the device under test.

The measuring section for mounting a calibrated (calibrated) meter is formed from a set of standard elements - conical transitions and flanged sections of the pipeline (straight sections). The centering of the elements of the measuring section in order to ensure their alignment is provided by technological supports, which have the ability to move along the frame along horizontal guides. A compressor is used to control the telescopic compensator and valves. For reliable support of the elements of the measuring section along the entire section, a rigid supporting structure (metal frame) is installed. Connecting pipelines are made of stainless steel and are designed to connect together all the nodes of the installation.

The control system 414, 514 provides automated control of the test installation, analysis of the readings of pressure and temperature sensors, as well as reference and calibrated meters. The specified control system 414, 514 is aimed at comparing the measurement readings obtained from the reference sections and the tested meters in the specified system of verified meters 406, and further calibration of the specified test device.

An injection system 407, 507 of the working medium is necessary for the initial supply of gas to the circuit 401, 501. A two-level system of cylinders 408, 508 of the injection system of the working medium 407, 507 is designed to create the necessary pressure in the pipeline system (closed loop) 401, 501 of the installation 400, 500 with the possibility of pumping various gases into the installation system until the required pressure is reached. The two-level system of high-pressure cylinders with different gases 408, 508 consists of a subsystem of cylinders with a pressure of 200 - 300 bar and a subsystem of cylinders with a pressure of 30 - 50 bar, preferably with separate heating. The gas required for testing (calibration, calibration) of meters (gas flow meters) is supplied from cylinders with a pressure of 200 - 300 bar to cylinders with a pressure of 30 - 50 bar, then gas from cylinders with a pressure of 30 - 50 bar is pumped into a closed high-pressure circuit.

The high pressure compressor 409, 509 is configured for:

- ensuring the return of the working medium from a closed loop 401, 501 to gas cylinders,

- ensuring pressure increase in the circuit 401, 501 and cylinders, equal to the pressure loss in the test setup 400 and in the system of cylinders 408, 508.

The damping tank 410, 510 helps to smoothly reduce the pressure from circuit 401 to compressor 409, 509 and protects the compressor from damage if there is a lot of pressure in circuit 401, 501.

The filter 411, 511 is installed in the pipeline of the high pressure circuit 401, 501. It is configured to remove contaminants from the stream circulating in the closed circuit 401, 501 of the test setup 400, 500, and to prevent contamination of the reference meters.

An inert gas unit 412, 512 connected to the pipeline of the high pressure circuit 401, 501 delivers inert gas to the closed high pressure circuit 401, 501.

A vacuum compressor 413, 513 is provided to remove residual gases from the closed loop 401, 501.

The pipeline of the high pressure circuit 401, 501 is equipped with an emergency gas removal device from circuit 421, 521 with a gas indicator.

The principle of operation of the test installation 400, 500 is as follows:

- in the closed loop 401, 501 of the test setup 400, 500 from the system of cylinders 408, 508 of the discharge system 407, 507 a certain gas is supplied, which is necessary for testing the meter (flow meter). The injection system 407, 507 creates a smooth increase in the pressure of this gas in the circuit 401, 501 to achieve the required pressure level

- after reaching the necessary pressure of the working medium (gas) in the circuit 401, 501, the flow generator of the working medium 402, 502 creates a flow movement in the circuit 401, 501 at a given speed;

- the specified stream passes through a system of reference counters 405, 505 and a system of verified counters 406, 506;

- the control system 414, 514 compares the flow rate of the specified gas, measured by the system of reference meters 405, 505 with the flow rate of the specified gas, measured by the system of verified meters 406, 506 (tested device) and, taking into account the results of the comparison, carries out the subsequent calibration of the tested device.

Between the thermostabilizing chamber 403, 503 and the reference line 405, 505 anti-vibration inserts are installed that do not allow the transmission of mechanical high-frequency vibrations from the turbine with a hydraulic motor 519 to the reference line 405, 505 and from the reference line 405, 505 to the working line 406, 506.

To prevent acoustic pulsations from the reference line from entering the production line, a flow preparation unit is used.

When the fan is turned on, a gas flow is created in the pipeline path of the installation. The gas flow can be adjusted by changing the fan speed. The flow rate, m ³ / h, is controlled by one of the reference meters. During a given time interval, the installation equipment counts the number of pulses generated by the verified and reference counters. By multiplying by the price of the impulse, individual for the calibrated and the reference meter, gas volumes are calculated under operating conditions. Next, the gas volumes are recalculated to standard conditions. The error is calculated by comparing the volumes of gas under standard conditions, measured by the calibrated and reference meters.

There are several options for limiting the measurement cycle: for a given number of pulses of a leading counter, for a given volume of gas, for a given test time. Or the measurement cycle can be limited manually.

The installation of a closed loop for the calibration of gas meters at a pressure of 400, 500 provides many advantages compared with the known inventions. Installation 400, 500 can work for several hours. The working environment does not need to be emitted into the atmosphere, therefore, the noise problem associated with purging the systems can be avoided. In overall dimensions, the installation is 400, 500 smaller than previously known. Installation 400, 500 may be small enough to be housed in a building. Installation 400, 500 cheaper than installations of known inventions, uses less expensive components, making it available to many companies.

As previously noted, the installation at Southwest Research Institute 200 uses a very large compressor that adds a lot of heat to the gas. Thus, the installation at Southwest Research Institute 200 needs a very large cooling system. A large compressor and a large cooling system for operation require large amounts of electricity.

The medium flow generator 402, 502 of the proposed installation 400, 500 has an electric motor 516, which is located outside the closed loop 401, 501. The energy released by the electric motor 516 is scattered in the atmosphere during operation and, due to the lack of contact, is not transferred to the working medium inside the closed circuit 401, 501. The turbine 520 with a hydraulic motor 519 in the installation 400, 500 is relatively small and, due to the use of a hydraulic motor 519, heats up the working medium practically little. The presence of an additional circuit 525 with a hydraulic fluid flowing through the cooler 518 almost completely eliminates the energy released by the flow generator 502 into the working medium of the closed circuit 401, 501. Thus, the 400, 500 installation requires only a small heat-stabilizing chamber 403, 503 to remove from the working medium is the heat arising from its movement and from the rotation of the hydraulic motor. Thus, for thermal stabilization of the working environment it requires much less electricity than installations of known inventions.

The use of a two-level system of cylinders 508 provides the ability to quickly change the working medium in a closed loop and, therefore, calibrate the meter exactly on the medium in which it will be operated. Heated 524 gas cylinders of the second level 523 provides additional stabilization of the temperature of the working fluid in a closed loop.

The use of the hydraulic drive of the turbine 520 in the flow generator 502 eliminates the need for complex technical solutions for the explosion protection of the flow generator and the entire installation.

Claims (44)

1. Installation (400) for calibrating gas meters in a closed circuit under high pressure, containing - high pressure flow loop 401, - medium flow generator (402), - temperature control system (403), connected during operation with the circuit, - a control unit (404) for supplying a working medium, - a system (405) of reference meters with the possibility of connection during operation with the specified closed loop, - a system for pumping a working medium (407), which creates excess pressure in the pipeline system, - a system of high pressure cylinders (408) with various gases with the possibility of connection during operation with the circuit of the test setup, characterized in that it contains - an electric motor (516) located outside the closed flow circuit (401, 501) and driving a hydraulic motor (519) with the help of a hydraulic pump (517), which is located inside the closed medium circuit (401, 501); - a turbine (520) located inside a closed circuit (401, 501), driven by a hydraulic motor (519) and designed to create and control the gas flow rate in a closed installation pipeline system; - an additional closed loop (525) of the hydraulic drive of the generator (402, 502) of the working fluid stream, equipped with an electric motor (516), a hydraulic pump (517), a cooler (518) and a hydraulic motor (519) that rotates the turbine (520), as well as a system for pumping the working medium (407, 507) connected to it, including a two-level system of high-pressure cylinders with gases (408, 508), a high-pressure compressor (409, 509) and a damping tank (410, 510). 2. Installation (400) according to claim 1,  characterized in - that the system of verified meters (406) is placed after the system of reference meters (405) in the direction of flow; - that the pipeline of the high pressure circuit (401) is equipped with an emergency gas removal device from the circuit (421) with a gas indicator; - that damping anti-vibration inserts are installed between sections of the pipeline of the high pressure circuit (401); - that it is equipped with a vacuum compressor (413), which ensures the removal of gas residues from a closed high pressure circuit (401); - that it contains an inert gas unit (412) connected to the pipeline of the high pressure circuit (401), 3. Installation (400) according to claim 1,  characterized by the presence of: control unit for supplying a working medium at low volumetric flows (404, 504) with sound nozzles and a shutoff valve system for switching and regulating the flow rate range. 4. Installation according to claim 1, characterized in that - that the reference sections are connected in parallel and - that each of the reference sections contains a reference counter. 5. Installation (400) according to claim 1,  characterized in - that the two-level system of high-pressure cylinders with gases (408, 508) consists of a subsystem (522) of cylinders with a pressure of 200-300 bar and a subsystem (523) of cylinders with a pressure of 30-50 bar with heating (524) separately or all together, - that the gas necessary for testing the meters is supplied from cylinders with a pressure of 200-300 bar to cylinders with a pressure of 30-50 bar, and - that further gas from cylinders with a pressure of 30-50 bar is pumped into a closed high-pressure circuit. 6. Installation (400) according to claim 1,  characterized in  that the high-pressure cylinder system (408, 508) works with various gases. 7. The method of operation of the installation according to one of paragraphs. 1-6, in which  - in the closed loop (401, 501) of the installation (400, 500) from the cylinder system (408, 508) of the discharge system (407, 507) a certain gas is supplied, which is necessary for testing the meter, and the discharge system (407, 507) creates a smooth increase the pressure of this gas in the circuit (401, 501) until the required pressure level is reached; - upon reaching the necessary pressure of the working medium in the circuit (401, 501), it creates a flow movement at a given speed; - the specified stream passes through a system of reference counters (405, 505) and a system of verified counters (406, 506); - measurements of the flow rate of the specified gas by the system of reference meters (405, 505) are compared with the flow measurements by the system of calibrated meters in the control system, - then, if necessary, calibrate the test meter, characterized in that - use the hydraulic actuator of the fluid flow generator (402, 502) by actuating the turbine (520) with the help of a hydraulic motor driven by a hydraulic fluid supplied by a hydraulic pump (517), which, in turn, is driven by an electric motor (516); outside the closed loop (401, 501), and - use a thermostabilizing chamber (503), a hydraulic fluid cooler (518) and heating of gas cylinders (524). 8. The method according to p. 7, characterized in that the adjustment block is used at low flow rates (404, 504), which provides high stability of the medium flow at low flow rates.

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