CN107884040B - Switch control method and device of quick reversing valve - Google Patents

Switch control method and device of quick reversing valve Download PDF

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CN107884040B
CN107884040B CN201610877818.0A CN201610877818A CN107884040B CN 107884040 B CN107884040 B CN 107884040B CN 201610877818 A CN201610877818 A CN 201610877818A CN 107884040 B CN107884040 B CN 107884040B
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reversing valve
quick
time
quick reversing
back pressure
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CN107884040A (en
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任佳
段继芹
王强
周芳
韦颜
陈荟宇
樊兰蓓
陈晓科
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Petrochina Co Ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
    • G01F25/10—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K31/00—Actuating devices; Operating means; Releasing devices

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Abstract

The invention discloses a switch control method and device of a quick reversing valve, and belongs to the technical field of gas flow measurement. The device is applied to a gas flow primary standard device, and the gas flow primary standard device comprises at least two quick reversing valves and a sonic nozzle; the method comprises the following steps: acquiring the switching time characteristic of each quick reversing valve; calculating the time for the back pressure ratio of the sonic nozzle to reach a preset back pressure ratio under different pressure and flow conditions according to the switching time characteristics of each quick reversing valve; and controlling the on-off of the quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio. The switching control device of the quick reversing valve comprises: the device comprises an acquisition module, a calculation module and a control module. The invention reduces the uncertainty level of the primary standard device of the gas flow and ensures the reliability of asynchronous reversing time difference.

Description

Switch control method and device of quick reversing valve
Technical Field
The invention relates to the technical field of gas flow measurement, in particular to a method and a device for controlling the opening and closing of a quick reversing valve.
Background
The domestic and foreign gas primary standard device is used for detecting or calibrating a high-accuracy sonic nozzle or other flowmeters, a rapid reversing system is needed to rapidly switch the gas flow direction, the measurement of the gas filling time is completed in a matching manner, and the mass flow of the gas flow primary standard device is obtained by combining the measurement result or the calculation result with the mass measurement result or the calculation result. In the primary standard device of gas flow, the quick reversing system is mainly composed of two quick reversing valves and an actuating mechanism thereof. Therefore, the rapid reversing system is a key device in the gas flow primary standard device, the switching control mode of the rapid reversing system directly influences the technical level of the gas flow primary standard device, and the rapid reversing system also has important influence on the overall level of a gas flow quantity value transmission system.
At present, in the related art, there are two methods for controlling the opening and closing of the quick reversing valve, and one control method is a synchronous reversing quick reversing method, that is, the quick reversing valve is controlled to be opened at the same time or closed at the same time. The other control mode is a rapid reversing mode adopting asynchronous reversing, namely, the rapid reversing valve is controlled to be opened at different times or closed at different times.
In the process of implementing the invention, the inventor finds that the prior art has at least the following defects:
the adoption of a synchronous reversing quick reversing mode can cause non-metering loss and influence the further improvement of the uncertainty level of the original standard device; the adoption of a fast commutation mode of asynchronous commutation can result in low reliability of asynchronous commutation time difference.
Disclosure of Invention
In order to solve the problems of the related art, the embodiment of the invention provides a method and a device for controlling the opening and closing of a quick reversing valve. The technical scheme is as follows:
on one hand, the method is applied to a gas flow primary standard device, and the gas flow primary standard device comprises at least two rapid reversing valves and a sonic nozzle; the method comprises the following steps:
acquiring the switching time characteristic of each quick reversing valve;
calculating the time for the back pressure ratio of the sonic nozzle to reach a preset back pressure ratio under different pressure and flow conditions according to the switching time characteristics of each quick reversing valve;
and controlling the on-off of the rapid reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio.
Optionally, the gas flow primary standard device comprises a first quick reversing valve and a second quick reversing valve; obtaining a switching time characteristic of a first fast reversing valve, comprising:
when the time for opening the valve of the pipeline where the first quick reversing valve is located and the time for closing the second quick reversing valve reach first preset time, after the first quick reversing valve is closed, the time for closing the first quick reversing valve is obtained, and the pressure and the temperature of a medium in the pipeline where the first quick reversing valve is located are obtained;
after the first quick reversing valve is opened, acquiring the opening time of the first quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the first quick reversing valve is located;
and repeating the above process for a first preset number of times, and acquiring the switching time characteristic of the first quick reversing valve according to the medium pressure and temperature in the pipeline where the first quick reversing valve is located and the opening time and closing time of the first quick reversing valve.
Optionally, obtaining the switching time characteristic of the second quick reversing valve includes:
when the time for opening the valve of the pipeline where the second quick reversing valve is located and the time for closing the second quick reversing valve reach second preset time, closing the first quick reversing valve, and after the first quick reversing valve is completely closed and begins to open the second quick reversing valve, acquiring the time for opening the second quick reversing valve and acquiring the pressure and temperature of a medium in the pipeline where the second quick reversing valve is located;
after the second quick reversing valve is closed, acquiring the closing time of the second quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the second quick reversing valve is located;
and repeating the above process for a second preset number of times, and acquiring the switching time characteristic of the second quick reversing valve according to the medium pressure and the temperature in the pipeline where the second quick reversing valve is located and the opening time and the closing time of the second quick reversing valve.
Optionally, the calculating, according to the switching time characteristic of each fast directional control valve, the time for the back pressure ratio of the sonic nozzle to reach the preset back pressure ratio under different pressure and flow conditions includes:
according toThe switching time characteristic of each quick reversing valve is used for calculating the time t when the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio according to the following formula under the conditions of different pressures and flow ratesmin：
Figure GDA0002186072130000021
Wherein the rho0The gas density in the closed pipeline is obtained when the gas medium flows from the inlet to the outlet before rapid reversing; the rhoxThe gas density is the gas density when the gas medium flows from the inlet to the gas container after rapid reversing and the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio x; q is a number ofmMass flow rate of sonic nozzle, VSupplement deviceThe volume of the pipeline is closed when the gas medium flows from the inlet to the outlet before rapid reversing.
Optionally, the controlling the switch of the fast reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio includes:
determining the time difference of the switch of each quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio;
and controlling the on-off of each quick reversing valve according to the time difference.
On the other hand, the switch control device of the quick reversing valve is applied to a gas flow primary standard device, and the gas flow primary standard device comprises at least two quick reversing valves and a sonic nozzle; the switching control device of the quick reversing valve comprises:
the acquisition module is used for acquiring the switching time characteristic of each quick reversing valve;
the calculation module is used for calculating the time for the back pressure ratio of the sonic nozzle to reach the preset back pressure ratio under different pressure and flow conditions according to the switching time characteristics of each quick reversing valve;
and the control module is used for controlling the on-off of the quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio.
Optionally, the gas flow primary standard device comprises a first quick reversing valve and a second quick reversing valve;
the acquisition module is used for acquiring the closing time of the first quick reversing valve after the first quick reversing valve is closed when the time for opening the valve of the pipeline where the first quick reversing valve is located and closing the second quick reversing valve reaches a first preset time, and acquiring the pressure and the temperature of a medium in the pipeline where the first quick reversing valve is located;
after the first quick reversing valve is opened, acquiring the opening time of the first quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the first quick reversing valve is located;
and repeating the above process for a first preset number of times, and acquiring the switching time characteristic of the first quick reversing valve according to the medium pressure and temperature in the pipeline where the first quick reversing valve is located and the opening time and closing time of the first quick reversing valve.
Optionally, the obtaining module is configured to close the first quick reversing valve when the time for opening the valve of the pipeline where the second quick reversing valve is located and closing the second quick reversing valve reaches a second preset time, and obtain the time for opening the second quick reversing valve after the first quick reversing valve is completely closed and the second quick reversing valve is opened, and obtain the pressure and the temperature of a medium in the pipeline where the second quick reversing valve is located;
after the second quick reversing valve is closed, acquiring the closing time of the second quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the second quick reversing valve is located;
and repeating the above process for a second preset number of times, and acquiring the switching time characteristic of the second quick reversing valve according to the medium pressure and the temperature in the pipeline where the second quick reversing valve is located and the opening time and the closing time of the second quick reversing valve.
Optionally, the calculating module is configured to calculate, according to the switching time characteristics of each fast directional control valve, under different pressure and flow conditions, according to the following equationCalculating the time t for the back pressure ratio of the sonic nozzle to reach the preset back pressure ratiomin：
Figure GDA0002186072130000041
Wherein the rho0The gas density in the closed pipeline is obtained when the gas medium flows from the inlet to the outlet before rapid reversing; the rhoxThe gas density is the gas density when the gas medium flows from the inlet to the gas container after rapid reversing and the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio x; q is a number ofmMass flow rate of sonic nozzle, VSupplement deviceThe volume of the pipeline is closed when the gas medium flows from the inlet to the outlet before rapid reversing.
Optionally, the control module includes:
the determining unit is used for determining the time difference of the switch of each quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio;
and the control unit is used for controlling the on-off of each quick reversing valve according to the time difference.
The technical scheme provided by the embodiment of the invention has the following beneficial effects:
by acquiring the switching time characteristic of the rapid reversing valve and combining the problem of non-metering leakage during rapid reversing which needs to be solved in the actual operation of the gas flow primary standard device, the theoretical reversing valve linkage switching method is provided, and the requirement of the back pressure ratio in the gas flow primary standard device can be guaranteed, so that the uncertainty level of the gas flow primary standard device is reduced, the reliability of asynchronous reversing time difference is guaranteed, and the method has a wide application prospect.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a flowchart of a method for controlling opening and closing of a quick directional control valve according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a primary standard device for gas flow according to another embodiment of the present invention;
FIG. 3 is a schematic diagram of the switching time characteristic of a quick change valve according to another embodiment of the present invention;
FIG. 4 is a schematic diagram of the switching time characteristic of a quick change valve according to another embodiment of the present invention;
FIG. 5 is a schematic diagram of the switching time characteristic of a quick change valve according to another embodiment of the present invention;
FIG. 6 is a schematic diagram of an on-off control for a quick change valve according to another embodiment of the present invention;
fig. 7 is a schematic diagram of an on-off control device of a quick change valve according to another embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
At present, the gas primary standard devices at home and abroad generally adopt two types of mass-time methods or PVTt methods which can directly trace to SI unit, and are used for the verification or calibration of high-accuracy sonic nozzles or other flowmeters. In addition, the international advanced level of the current gas flow primary standard device adopting air as a medium is 0.04 percent of mass flow uncertainty, and the international advanced level of the gas flow primary standard device adopting natural gas as a medium is 0.1 percent of mass flow uncertainty. In the two types of primary standard devices, a rapid reversing system is required to rapidly switch the gas flow direction, and the mass flow of the gas flow primary standard device is obtained by combining the measurement of the inflation time and the mass measurement result or the calculation result. Therefore, the rapid reversing system is a key device in the gas flow primary standard device, the switching speed, the repeatability of the switching time and the switching mode of the rapid reversing system directly influence the technical level of the gas flow primary standard device, and the rapid reversing system also has an important influence on the overall level of a gas flow magnitude value transmission system.
In the primary standard device of gas flow, the quick reversing system is mainly composed of at least two quick reversing valves and an actuating mechanism thereof. The embodiment provides a switching control method of a quick reversing valve, which is applied to a gas flow primary standard device, wherein the gas flow primary standard device comprises at least two quick reversing valves and a sonic nozzle. Referring to fig. 1, the method provided in this embodiment includes:
101: acquiring the switching time characteristic of each quick reversing valve;
as an alternative embodiment, the gas flow primary standard device comprises a first quick reversing valve and a second quick reversing valve; obtaining a switching time characteristic of a first fast reversing valve, comprising:
when the time for opening the valve of the pipeline where the first quick reversing valve is located and closing the second quick reversing valve reaches first preset time, after the first quick reversing valve is closed, the time for closing the first quick reversing valve is obtained, and the pressure and the temperature of a medium in the pipeline where the first quick reversing valve is located are obtained;
after the first quick reversing valve is opened, acquiring the opening time of the first quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the first quick reversing valve is located;
and repeating the process for a first preset number of times, and acquiring the switching time characteristic of the first quick reversing valve according to the medium pressure and temperature in the pipeline where the first quick reversing valve is located and the opening time and closing time of the first quick reversing valve.
As an alternative, obtaining the switching time characteristic of the second fast reversing valve comprises:
when the time for opening the valve of the pipeline where the second quick reversing valve is located and the time for closing the second quick reversing valve reach second preset time, closing the first quick reversing valve, and after the first quick reversing valve is completely closed and begins to open the second quick reversing valve, acquiring the time for opening the second quick reversing valve and acquiring the pressure and temperature of a medium in the pipeline where the second quick reversing valve is located;
after the second quick reversing valve is closed, acquiring the closing time of the second quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the second quick reversing valve is located;
and repeating the process for a second preset number of times, and acquiring the switching time characteristic of the second quick reversing valve according to the medium pressure and temperature in the pipeline where the second quick reversing valve is located and the opening time and closing time of the second quick reversing valve.
The switching time characteristic of the quick reversing valve is used for expressing the change process of pressure and temperature along with the opening time and the closing time of the quick reversing valve.
102: calculating the time for the back pressure ratio of the sonic nozzle to reach a preset back pressure ratio under different pressure and flow conditions according to the switching time characteristics of each quick reversing valve;
as an alternative embodiment, the calculating the time for the back pressure ratio of the sonic nozzle to reach the preset back pressure ratio under different pressure and flow rate conditions according to the on-off time characteristics of each quick switching valve comprises:
according to the switching time characteristic of each quick reversing valve, under the conditions of different pressures and flow rates, the time t for the back pressure ratio of the sonic nozzle to reach the preset back pressure ratio is calculated according to the following formulamin：
Figure GDA0002186072130000061
Where ρ is0The gas density in the closed pipeline is obtained when the gas medium flows from the inlet to the outlet before rapid reversing; rhoxThe gas density is the gas density when the gas medium flows from the inlet to the gas container after rapid reversing and the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio x; q. q.smMass flow of sonic nozzle, VSupplement deviceThe volume of the pipeline is closed when the gas medium flows from the inlet to the outlet before rapid reversing.
103: and controlling the on-off of the quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio.
As an alternative embodiment, the controlling of the opening and closing of the quick change valve according to the time when the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio includes:
determining the time difference of the switch of each quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio;
and controlling the on-off of each quick reversing valve according to the time difference.
During specific implementation, selecting an initial time difference, judging whether the initial time difference meets the condition according to the switching time characteristic of the quick reversing valve and the time when the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio, and if the initial time difference does not meet the condition, readjusting the time difference until the time difference meeting the condition is obtained; if the conditions are met, controlling the on-off of each quick reversing valve according to the time difference meeting the conditions, and recording the pressure and the temperature in the pipeline of each quick reversing valve; judging whether the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio or not according to the recorded pressure and temperature; if not, reducing or increasing the time difference, and ensuring that the reduced or increased time difference still meets the conditions, then controlling the switch of each quick reversing valve according to the adjusted time difference, and recording the pressure and the temperature in the pipeline of the quick reversing valve; and judging whether the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio or not according to the recorded pressure and temperature, circulating until the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio, and taking the time difference reaching the preset back pressure ratio as the time difference of switching each quick reversing valve.
Specifically, whether the time difference meets the condition is judged, including but not limited to judging whether the time for controlling the linkage switch of the quick reversing valve by adopting the time difference is less than the time for controlling the linkage switch of the quick reversing valve to be opened or closed simultaneously according to the opening and closing time characteristic of the quick reversing valve, if so, the condition is met, and if not, the condition is not met.
According to the method provided by the embodiment, by acquiring the switching time characteristic of the rapid reversing valve and combining the problem of non-metering leakage during rapid reversing which needs to be solved in the actual operation of the gas flow primary standard device, a theoretical reversing valve linkage switching method capable of guaranteeing the back pressure ratio requirement in the gas flow primary standard device is provided, the uncertainty level of the gas flow primary standard device is reduced, the reliability of asynchronous reversing time difference is guaranteed, and the method has a wide application prospect.
For convenience of understanding, the method provided in this embodiment is illustrated by taking the schematic structural diagram of the primary standard device of gas flow rate shown in fig. 2 as an example. As shown in fig. 2, the gas flow primary standard device comprises an air inlet ball valve (1), a sonic nozzle (2), a first ball valve (3), a first quick reversing valve (4), an exhaust valve (5), a second quick reversing valve (6), a second ball valve (7), a container inlet ball valve (8), a gas container (9), a first quick temperature sensor (10), a first quick pressure sensor (11), a second quick temperature sensor (12), a second quick pressure sensor (13), a first photoelectric shaft angle encoder (14) and a second photoelectric shaft angle encoder (15); the air inlet ball valve (1), the sonic nozzle (2), the first ball valve (3), the second quick reversing valve (6), the second ball valve (7), the container inlet ball valve (8) and the gas container (9) are sequentially connected; a first rapid temperature sensor (10) and a first rapid pressure sensor (11) are connected between the first ball valve (3) and the second rapid reversing valve (6); a second rapid temperature sensor (12) and a second rapid pressure sensor (13) are connected between the second rapid reversing valve (6) and the second ball valve (7); the first quick reversing valve (4) and the exhaust valve (5) are connected between the first quick temperature sensor (10) and the first quick pressure sensor (11); the first photoelectric shaft angle encoder (14) is connected to the first quick reversing valve (4); the second photoelectric shaft angle encoder (15) is connected to the second quick reversing valve (6). Let is the air inlet, and outlet is the gas outlet.
With reference to the schematic structural diagram of the primary standard device of gas flow shown in fig. 2, the method for controlling the on/off of the quick directional control valve provided in this embodiment includes:
301: acquiring the switching time characteristic of the first quick reversing valve (4);
as shown in fig. 2, the pipeline where the first quick reversing valve (4) is located is the pipeline where the air inlet ball valve (1), the first ball valve (3), the first quick reversing valve (4) and the exhaust valve (5) are located, and when the switching time characteristic of the first quick reversing valve (4) is obtained, the method includes the following processes:
when the valve of the pipeline where the first quick reversing valve (4) is located is opened, namely the air inlet ball valve (1), the first ball valve (3), the first quick reversing valve (4) and the exhaust valve (5) are opened, the second quick reversing valve (6) is closed, or the second quick reversing valve (6), the second ball valve (7) and the container inlet ball valve (8) are all closed for a first preset time, the medium is enabled to stably flow in the pipeline. After the first quick reversing valve (4) is closed, the time process of closing the first quick reversing valve (4) recorded by the first photoelectric shaft angle encoder (14) is acquired, and the temperature of the medium in the pipeline measured by the first quick temperature sensor (10) and the pressure of the medium in the pipeline measured by the first quick pressure sensor (11) are acquired.
When the first quick reversing valve (4) starts to be opened, acquiring the time process of recording the opening of the first quick reversing valve (4) by using a first photoelectric shaft angle encoder (14), and acquiring the pressure and the temperature of a medium in the pipeline, which are measured by a first quick pressure sensor (11) and a first quick temperature sensor (10) when the response time reaches the preset time;
and repeating the process for a first preset number of times, and obtaining the switching time characteristic of the first quick reversing valve (4) according to the medium pressure and the temperature in the pipeline where the first quick reversing valve (4) is located and the opening time and the closing time of the first quick reversing valve (4).
Wherein the switching time characteristic of the first quick change valve (4) is used for expressing the change process of pressure and temperature along with the opening time and the closing time of the first quick change valve (4). In addition, the first preset time and the first preset number are not limited in this embodiment, for example, the first preset time may be 3 milliseconds, 4 seconds, and the like, and the first preset number may be 6 times, 8 times, and the like.
Taking the first preset number of times as an example, the switching time characteristic of the first quick direction valve (4) obtained according to the above process can be shown in fig. 3. In fig. 3, time 1 is a state immediately after the first quick change valve (4) is closed, and time 2 is a state where the first quick change valve (4) is completely closed. The moment 3 is the state that the first quick reversing valve (4) just starts to be opened, and the moment 4 is the state that the first quick reversing valve (4) is completely opened. 5 is the measured value of the first fast pressure sensor (11) or the first fast temperature sensor (10) and 6 is the time.
302: acquiring the switching time characteristic of a second quick reversing valve (6);
when the switching time characteristic of the second quick reversing valve (6) is obtained, the method comprises the following processes: when the air inlet ball valve (1), the first ball valve (3), the first quick reversing valve (4), the exhaust valve (5), the second quick reversing valve (6), the second ball valve (7) and the container inlet ball valve (8) are opened, the second quick reversing valve (6) is closed, and after second preset time, a medium stably flows in the pipeline. After the first quick reversing valve (4) is completely closed and the second quick reversing valve (6) is opened, acquiring the time process of opening the second quick reversing valve (6) recorded by a second photoelectric shaft angle encoder (15), and acquiring medium pressure and temperature in the pipeline measured by a first quick temperature sensor (10), a first quick pressure sensor (11), a second quick pressure sensor (13) and a second quick temperature sensor (12);
when the second quick reversing valve (6) starts to be closed, acquiring medium pressure and temperature in the pipeline measured by the first quick temperature sensor (10), the first quick pressure sensor (11), the second quick pressure sensor (13) and the second quick temperature sensor (12);
and repeating the process for a second preset time, and obtaining the switching time characteristic of the second quick reversing valve (6) according to the medium pressure and the temperature in the pipeline where the second quick reversing valve (6) is located and the opening time and the closing time of the second quick reversing valve (6).
Wherein the switching time characteristic of the second quick change valve (6) is used for expressing the change process of the pressure and the temperature along with the opening time and the closing time of the second quick change valve (6). In addition, the second preset time and the second preset times are not limited in this embodiment, and the second preset time may be the same as the first preset time or different from the first preset time. The second preset number may be the same as the first preset number, or may be different from the first preset number. For example, the second preset time may be 3 milliseconds, 4 seconds, etc., and the second preset number may be 6 times, 8 times, etc.
Taking the second preset number of times as an example of 6 times, the switching time characteristic of the second quick direction valve (6) obtained according to the above process can be shown in fig. 4 and 5. In fig. 4 and 5, it can be seen that the time 1 is the state when the second quick direction valve (6) is just opened, the time 2 is the state when the second quick direction valve (6) is fully opened, the time 3 is the state when the second quick direction valve (6) begins to be closed, and the time 4 is the state when the second quick direction valve (6) is fully closed. 5 is the measured value of the second fast pressure sensor (13) or the second fast temperature sensor (12), 6 is the time, and 7 is the measured value of the first fast pressure sensor (11) or the first fast temperature sensor (10).
303: according to the switching time characteristics of the first quick reversing valve (4) and the second quick reversing valve (6), under the conditions of different pressures and flow rates, calculating the time for the ratio of the pressure in a closed pipeline formed by the sonic nozzle (2) and the first quick reversing valve (4) and the second quick reversing valve (6) to the upstream pressure of the sonic nozzle (2) to reach the required back pressure ratio;
according to the following formula, under different pressure and flow conditions, the time t when the ratio of the pressure in a closed pipeline formed by the sonic nozzle (2) and the first quick reversing valve (4) and the second quick reversing valve (6) to the upstream pressure of the sonic nozzle (2) reaches the required back pressure ratio is calculatedmin：
Figure GDA0002186072130000101
Wherein the rho0The gas density in the closed pipeline is obtained when the gas medium flows from the inlet to the outlet before rapid reversing; rhoxThe gas density is that after the gas medium is quickly reversed, the gas medium flows from the inlet to the gas container (9) and the back pressure ratio of the sonic nozzle (2) reaches the required back pressure ratio x; q. q.smMass flow of sonic nozzle, VSupplement deviceThe volume of the pipeline is closed when the gas medium flows from the inlet to the outlet before rapid reversing.
The ratio of the pressure in the closed duct formed by the sonic nozzle (2) and the first and second quick change valves (4, 6) to the pressure upstream of the sonic nozzle (2) may be a sonic nozzle back pressure ratio, and the required back pressure ratio may be 0.85, that is, x is 0.85. Of course, x may also be other values, which is not specifically limited in this embodiment.
304: and controlling the linkage switch of the two quick reversing valves according to the time when the ratio of the pressure in the closed pipeline formed by the sonic nozzle (2), the first quick reversing valve (4) and the second quick reversing valve (6) to the upstream pressure of the sonic nozzle (2) reaches the required back pressure ratio.
As an alternative embodiment, the step 304 includes the following two steps:
the method comprises the following steps: determining the time difference of the opening and closing of the first quick reversing valve (4) and the second quick reversing valve (6) according to the time when the ratio of the pressure in a closed pipeline formed by the sonic nozzle (2), the first quick reversing valve (4) and the second quick reversing valve (6) to the upstream pressure of the sonic nozzle (2) reaches the required back pressure ratio;
for convenience of description, the time that the ratio of the pressure in the closed pipeline formed by the sonic nozzle (2), the first quick reversing valve (4) and the second quick reversing valve (6) and the upstream pressure of the sonic nozzle (2) obtained by calculation in the step 303 reaches the required backpressure ratio is simply referred to as reference time, a time difference can be set when the time difference of opening and closing the first quick reversing valve (4) and the second quick reversing valve (6) is determined according to the reference time, whether the set time difference meets the condition or not is judged according to the opening and closing time characteristics of the first quick reversing valve (4) and the second quick reversing valve (6) and the reference time, and if the condition is met, the following step two is executed; if the condition is not met, the time difference is readjusted until the time difference meeting the condition is obtained, and then the following step two is executed.
The method for judging whether the time difference meets the condition or not according to the switching time characteristics and the reference time of the first quick reversing valve (4) and the second quick reversing valve (6) comprises the following steps: and judging whether the time for simultaneously closing the two quick reversing valves is less than the reference time or not when the two quick reversing valves are controlled to be linked and switched by adopting the time difference according to the switching time characteristics of the first quick reversing valve (4) and the second quick reversing valve (6). If the time difference is smaller than the preset time difference, the time difference is the time difference meeting the condition, and if the time difference is not smaller than the preset time difference, the time difference is the time difference not meeting the condition.
Step two: and controlling the linkage switch of the first quick reversing valve (4) and the second quick reversing valve (6) according to the time difference.
When the linked switches of the first quick reversing valve (4) and the second quick reversing valve (6) are controlled according to the time difference, the switches of the first quick reversing valve (4) and the second quick reversing valve (6) are controlled according to the time difference determined in the step one; recording the pressure and the temperature in the pipelines of the first quick reversing valve (4) and the second quick reversing valve (6); judging whether the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio or not according to the recorded pressure and temperature; if not, returning to the step I, reducing or increasing the time difference, and ensuring that the reduced or increased time difference still meets the conditions of the step I, then repeating the step II until the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio, and taking the time difference reaching the preset back pressure ratio as the time difference of each quick reversing valve switch.
In the gas flow primary standard device shown in fig. 2, when the inlet ball valve (1), the first ball valve (3), the exhaust valve (5), the second ball valve (7), the container inlet ball valve (8) and the first quick reversing valve (4) are opened, the time difference delta t is carried out0The second quick reversing valve (6) is opened and the first quick reversing valve (4) is closed, and medium pressure and temperature in the pipeline measured by the first quick pressure sensor (11), the first quick temperature sensor (10), the second quick pressure sensor (13) and the second quick temperature sensor (12) are synchronously recorded. And determining whether the back pressure ratio of the sonic nozzle can be ensured to be less than 0.85 or not according to the variation trends of the pressure and the temperature along with the opening and closing time of the second quick reversing valve (6) and the first quick reversing valve (4). If less than 0.85, the ganged switching method of the two quick change valves is appropriate. If greater than 0.85, the time difference Δ t is reduced0And repeating the measurement process until the back pressure ratio of the sonic nozzle is less than 0.85, and optimizing the linkage switching method of the two quick reversing valves.
The embodiment of the invention adopts the temperature and pressure sensors with quick response to measure the quick change trends of the medium pressure and the temperature when the quick reversing valve of the original natural gas flow standard device is switched, and forms an optimal linkage switching method for quantitatively measuring the switching characteristics of the quick reversing valve group and the two reversing valves by analyzing the change trends and combining theoretical calculation, thereby quantitatively determining whether the synchronous switch or the asynchronous switch is switched under different working conditions and the time difference of the asynchronous switch, and finally improving the uncertainty level of mass flow measurement of the original natural gas flow standard device to reach 0.05 percent or even higher level.
In summary, the method provided in this embodiment provides a theoretical reversing valve linkage switching method by obtaining the switching time characteristic of the fast reversing valve and combining the problem of non-metering leakage during fast reversing that needs to be solved in the actual operation of the gas flow primary standard device, and can ensure the requirement of the back pressure ratio in the gas flow primary standard device, so that the uncertainty level of the gas flow primary standard device is reduced, the reliability of asynchronous reversing time difference is ensured, and the method has a wider application prospect.
Referring to fig. 6, a schematic structural diagram of an on-off control device of a quick change valve according to an embodiment of the present invention is shown. The switch control device of the rapid reversing valve is applied to a gas flow primary standard device, and the gas flow primary standard device comprises at least two rapid reversing valves and a sonic nozzle. The switching control device of the quick change valve is used for executing the switching control method of the quick change valve shown in the embodiment. As shown in fig. 6, the switching control apparatus of the quick change valve includes: an acquisition module 701, a calculation module 702 and a control module 703.
The acquiring module 701 is used for acquiring the switching time characteristics of each quick reversing valve;
a calculating module 702, configured to calculate, according to the switching time characteristics of each fast directional control valve, a time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio under different pressure and flow conditions;
and the control module 703 is used for controlling the on-off of the quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio.
As an alternative embodiment, the gas flow primary standard device comprises a first quick reversing valve and a second quick reversing valve;
the obtaining module 701 is configured to obtain the closing time of the first fast reversing valve after the first fast reversing valve is closed when the time for opening the valve of the pipeline where the first fast reversing valve is located and the time for closing the second fast reversing valve reach a first preset time, and obtain the pressure and the temperature of a medium in the pipeline where the first fast reversing valve is located;
after the first quick reversing valve is opened, acquiring the opening time of the first quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the first quick reversing valve is located;
and repeating the process for a first preset number of times, and acquiring the switching time characteristic of the first quick reversing valve according to the medium pressure and temperature in the pipeline where the first quick reversing valve is located and the opening time and closing time of the first quick reversing valve.
As an optional embodiment, the obtaining module 701 is configured to close the first quick reversing valve when the time for opening the valve of the pipeline where the second quick reversing valve is located and closing the second quick reversing valve reaches a second preset time, and obtain the time for opening the second quick reversing valve after the first quick reversing valve is completely closed and the second quick reversing valve is opened, and obtain the pressure and the temperature of a medium in the pipeline where the second quick reversing valve is located;
after the second quick reversing valve is closed, acquiring the closing time of the second quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the second quick reversing valve is located;
and repeating the process for a second preset number of times, and acquiring the switching time characteristic of the second quick reversing valve according to the medium pressure and temperature in the pipeline where the second quick reversing valve is located and the opening time and closing time of the second quick reversing valve.
As an alternative embodiment, the calculating module 702 is configured to calculate the time t for the sonic nozzle back pressure ratio to reach the preset back pressure ratio according to the following formula under different pressure and flow conditions according to the on-off time characteristics of each fast directional control valvemin：
Figure GDA0002186072130000131
Where ρ is0The gas density in the closed pipeline is obtained when the gas medium flows from the inlet to the outlet before rapid reversing; rhoxThe gas density is the gas density when the gas medium flows from the inlet to the gas container after rapid reversing and the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio x; q. q.smIs the mass flow rate of the sonic nozzle.
As an alternative embodiment, referring to fig. 7, the control module 703 includes:
a determining unit 7031, configured to determine a time difference between the on and off of each fast directional control valve according to a time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio;
and the control unit 7032 is used for controlling the on and off of each quick reversing valve according to the time difference.
As an alternative embodiment, the determining unit 7031 is configured to control the on/off of each fast directional valve according to the initial time difference; recording the pressure and temperature in the pipeline of the quick reversing valve; judging whether the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio or not according to the recorded pressure and temperature; if not, reducing the initial time difference, repeating the steps until the back pressure ratio of the sonic nozzle reaches the preset back pressure ratio, and taking the time difference reaching the preset back pressure ratio as the time difference of the switch of each quick reversing valve.
In summary, the switching control device of the rapid reversing valve provided in this embodiment provides a theoretical reversing valve linkage switching method by obtaining the switching time characteristic of the rapid reversing valve and combining the problem of non-metering leakage during rapid reversing that needs to be solved in the actual operation of the gas flow primary standard device, and can ensure the requirement of the back pressure ratio in the gas flow primary standard device, so that the uncertainty level of the gas flow primary standard device is reduced, the reliability of asynchronous reversing time difference is also ensured, and the switching control device has a wider application prospect.
It should be noted that, the sequence numbers of the steps in the foregoing method embodiments do not represent the order of executing the steps, and in practical application, the steps may be executed in any order.
It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working process of the apparatus described above may refer to the corresponding process in the method embodiment, and is not described herein again.
It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. The method is characterized in that the method is applied to a gas flow primary standard device, and the gas flow primary standard device comprises at least two rapid reversing valves and a sonic nozzle; the method comprises the following steps:
acquiring the switching time characteristic of each quick reversing valve;
calculating the time for the back pressure ratio of the sonic nozzle to reach a preset back pressure ratio under different pressure and flow conditions according to the switching time characteristics of each quick reversing valve;
and controlling the on-off of the rapid reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio.
2. The method of claim 1, wherein the primary gas flow standard device comprises a first quick change valve and a second quick change valve; obtaining a switching time characteristic of a first fast reversing valve, comprising:
when the time for opening the valve of the pipeline where the first quick reversing valve is located and the time for closing the second quick reversing valve reach first preset time, after the first quick reversing valve is closed, the time for closing the first quick reversing valve is obtained, and the pressure and the temperature of a medium in the pipeline where the first quick reversing valve is located are obtained;
after the first quick reversing valve is opened, acquiring the opening time of the first quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the first quick reversing valve is located;
and repeating the above process for a first preset number of times, and acquiring the switching time characteristic of the first quick reversing valve according to the medium pressure and temperature in the pipeline where the first quick reversing valve is located and the opening time and closing time of the first quick reversing valve.
3. The method of claim 2, wherein obtaining the switching time characteristic of the second fast reversing valve comprises:
when the time for opening the valve of the pipeline where the second quick reversing valve is located and the time for closing the second quick reversing valve reach second preset time, closing the first quick reversing valve, and after the first quick reversing valve is completely closed and begins to open the second quick reversing valve, acquiring the time for opening the second quick reversing valve and acquiring the pressure and temperature of a medium in the pipeline where the second quick reversing valve is located;
after the second quick reversing valve is closed, acquiring the closing time of the second quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the second quick reversing valve is located;
and repeating the above process for a second preset number of times, and acquiring the switching time characteristic of the second quick reversing valve according to the medium pressure and the temperature in the pipeline where the second quick reversing valve is located and the opening time and the closing time of the second quick reversing valve.
4. The method of claim 1, wherein calculating the time for the sonic nozzle backpressure ratio to reach a preset backpressure ratio based on the on-off time characteristics of each fast switching valve under different pressure and flow conditions comprises:
according to each quick changeCalculating the time t for the back pressure ratio of the sonic nozzle to reach the preset back pressure ratio according to the following formula under the conditions of different pressures and flow rates according to the switching time characteristic of the directional valvemin：
Figure FDA0001125503400000021
Wherein the rho0The gas density in the closed pipeline is obtained when the gas medium flows from the inlet to the outlet before rapid reversing; the rhoxThe gas density is the gas density when the gas medium flows from the inlet to the gas container after rapid reversing and the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio x; q is a number ofmMass flow rate of sonic nozzle, VSupplement deviceThe volume of the pipeline is closed when the gas medium flows from the inlet to the outlet before rapid reversing.
5. The method of any one of claims 1 to 4, wherein controlling the opening and closing of the fast reversing valve according to the time at which the sonic nozzle back pressure ratio reaches a preset back pressure ratio comprises:
determining the time difference of the switch of each quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio;
and controlling the on-off of each quick reversing valve according to the time difference.
6. The switch control device of the quick reversing valve is characterized in that the switch control device of the quick reversing valve is applied to a gas flow primary standard device, and the gas flow primary standard device comprises at least two quick reversing valves and a sonic nozzle; the switching control device of the quick reversing valve comprises:
the acquisition module is used for acquiring the switching time characteristic of each quick reversing valve;
the calculation module is used for calculating the time for the back pressure ratio of the sonic nozzle to reach the preset back pressure ratio under different pressure and flow conditions according to the switching time characteristics of each quick reversing valve;
and the control module is used for controlling the on-off of the quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio.
7. The switching control device of the rapid reversing valve according to claim 6, wherein the gas flow primary standard device comprises a first rapid reversing valve and a second rapid reversing valve;
the acquisition module is used for acquiring the closing time of the first quick reversing valve after the first quick reversing valve is closed when the time for opening the valve of the pipeline where the first quick reversing valve is located and closing the second quick reversing valve reaches a first preset time, and acquiring the pressure and the temperature of a medium in the pipeline where the first quick reversing valve is located;
after the first quick reversing valve is opened, acquiring the opening time of the first quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the first quick reversing valve is located;
and repeating the above process for a first preset number of times, and acquiring the switching time characteristic of the first quick reversing valve according to the medium pressure and temperature in the pipeline where the first quick reversing valve is located and the opening time and closing time of the first quick reversing valve.
8. The switch control device of the rapid reversing valve according to claim 7, wherein the obtaining module is configured to close the first rapid reversing valve when a time that a valve of a pipeline where the second rapid reversing valve is located is opened and the second rapid reversing valve is closed reaches a second preset time, and obtain a time that the second rapid reversing valve is opened and obtain a pressure and a temperature of a medium in the pipeline where the second rapid reversing valve is located after the first rapid reversing valve is completely closed and the second rapid reversing valve is opened;
after the second quick reversing valve is closed, acquiring the closing time of the second quick reversing valve, and acquiring the pressure and temperature of a medium in a pipeline where the second quick reversing valve is located;
and repeating the above process for a second preset number of times, and acquiring the switching time characteristic of the second quick reversing valve according to the medium pressure and the temperature in the pipeline where the second quick reversing valve is located and the opening time and the closing time of the second quick reversing valve.
9. The apparatus of claim 6, wherein the calculating module is configured to calculate the time t for the back pressure ratio of the sonic nozzle to reach the preset back pressure ratio according to the following formula under different pressure and flow conditions according to the on-off time characteristics of each fast directional valvemin：
Figure FDA0001125503400000031
Wherein the rho0The gas density in the closed pipeline is obtained when the gas medium flows from the inlet to the outlet before rapid reversing; the rhoxThe gas density is the gas density when the gas medium flows from the inlet to the gas container after rapid reversing and the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio x; q is a number ofmMass flow rate of sonic nozzle, VSupplement deviceThe volume of the pipeline is closed when the gas medium flows from the inlet to the outlet before rapid reversing.
10. The switching control device of the quick change valve as claimed in any one of claims 6 to 9, wherein the control module comprises:
the determining unit is used for determining the time difference of the switch of each quick reversing valve according to the time when the back pressure ratio of the sonic nozzle reaches a preset back pressure ratio;
and the control unit is used for controlling the on-off of each quick reversing valve according to the time difference.
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KR100928342B1 (en) * 2009-06-10 2009-11-26 주식회사 라스코 Waste discharging device with air nozzle
CN102141426A (en) * 2010-12-07 2011-08-03 浙江省计量科学研究院 Fluid reversing device and reversing and timing method
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