CN117389342A - High-precision constant-voltage control device and system - Google Patents
High-precision constant-voltage control device and system Download PDFInfo
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- CN117389342A CN117389342A CN202311540717.0A CN202311540717A CN117389342A CN 117389342 A CN117389342 A CN 117389342A CN 202311540717 A CN202311540717 A CN 202311540717A CN 117389342 A CN117389342 A CN 117389342A
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- 230000005540 biological transmission Effects 0.000 claims description 39
- 238000006073 displacement reaction Methods 0.000 claims description 18
- 239000000872 buffer Substances 0.000 claims description 15
- 238000012544 monitoring process Methods 0.000 claims description 8
- 238000004891 communication Methods 0.000 claims description 6
- 238000005086 pumping Methods 0.000 claims description 3
- 238000012546 transfer Methods 0.000 claims description 3
- 239000007789 gas Substances 0.000 description 108
- 238000005259 measurement Methods 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000006641 stabilisation Effects 0.000 description 2
- 238000011105 stabilization Methods 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000009530 blood pressure measurement Methods 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 230000003116 impacting effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D16/00—Control of fluid pressure
- G05D16/20—Control of fluid pressure characterised by the use of electric means
- G05D16/2006—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means
- G05D16/2013—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means
Abstract
The invention relates to the technical field of pressure control, and provides a high-precision constant-pressure control device and a high-precision constant-pressure control system.
Description
Technical Field
The invention relates to the technical field of pressure control, in particular to a high-precision constant pressure control device and a system.
Background
The constant pressure device is a device capable of providing stable pressure environment, is basic equipment required by some experimental environments, and is commonly used in the aspects of chemical reaction experiments, petrochemical industry fields, scientific experiments and the like.
The pressure control precision in the constant pressure device depends on the precision of the pressure gauge, the constant pressure device generally monitors the pressure by using a high-precision and high-stability piston pressure gauge, the piston pressure gauge comprises a cylinder body and a piston, the piston is slidably arranged in the cylinder body, the piston divides the cylinder body into an upper space and a lower space, the lower space is filled with working gas to be detected, a standard weight is placed in the upper space, and after the piston is in a balance position, the pressure control of the constant pressure device is performed according to the obtained pressure value as a feedback signal.
However, since a small gap exists between the piston and the cylinder of the piston pressure gauge, working gas in the lower space of the piston can leak and be lost through the gap, so that the pressure measured by the piston pressure gauge is unstable, and continuous pulse fluctuation of the gas pressure can occur in the process of transmitting the working gas, thereby affecting the pressure control precision of the constant pressure device.
Disclosure of Invention
The invention provides a high-precision constant-voltage control device and a system, which solve or at least partially solve the problems in the prior art.
A first aspect of the present invention provides a high-precision constant-pressure control device comprising:
a gas transmission line;
the first mass flowmeter and the second mass flowmeter are sequentially arranged on the gas transmission pipeline along the gas transmission direction, and at least the gas flow allowed to pass through by the second mass flowmeter is adjustable;
the piston pressure gauge comprises a cylinder body and a piston, wherein the piston is slidably arranged in the cylinder body and divides the cylinder body into an upper space and a lower space;
a constant pressure cavity;
the gas transmission pipeline between the first mass flowmeter and the second mass flowmeter is respectively communicated with the lower space of the piston pressure gauge and the constant pressure cavity;
a displacement sensor for measuring the height of the piston;
and the controller is electrically connected with the displacement sensor and the second mass flowmeter, so as to adjust the flow rate of the gas allowed to pass through by the second mass flowmeter according to the height change of the piston.
The high-precision constant-pressure control device provided by the invention further comprises:
the auxiliary monitoring unit comprises an auxiliary pipeline and a pressure measuring device;
wherein the gas transfer line between the first and second mass flow meters is in communication with the auxiliary line;
the pressure measuring device is arranged on the auxiliary pipeline and is used for measuring the pressure in the auxiliary pipeline.
According to the high-precision constant-pressure control device provided by the invention, the auxiliary monitoring unit further comprises a first buffer cavity arranged on the auxiliary pipeline.
According to the high-precision constant-pressure control device provided by the invention, the pressure measuring device comprises:
the first pressure sensor and the second pressure sensor are sequentially arranged on the auxiliary pipeline.
According to the high-precision constant pressure control device provided by the invention, a three-way valve is arranged on the gas transmission pipeline between the first mass flowmeter and the second mass flowmeter, and comprises a first end, a second end and a third end;
the first end is communicated with the air outlet end of the first mass flowmeter, and the second end is communicated with the air inlet end of the second mass flowmeter.
The high-precision constant-pressure control device provided by the invention further comprises:
the four-way valve comprises a fourth end, a fifth end, a sixth end and a seventh end;
the third end of the three-way valve is communicated with the fourth end of the three-way valve, the fifth end of the three-way valve is communicated with the constant pressure cavity, the sixth end of the three-way valve is communicated with the lower space of the piston pressure gauge, and the seventh end of the three-way valve is communicated with the auxiliary pipeline.
The high-precision constant-pressure control device provided by the invention further comprises:
the gas cylinder is communicated with the gas transmission pipeline;
the pressure reducing valve is arranged on the gas transmission pipeline between the gas cylinder and the first mass flowmeter;
and the second buffer cavity is arranged on the gas transmission pipeline between the pressure reducing valve and the first mass flowmeter.
According to the high-precision constant-pressure control device provided by the invention, the air outlet end of the second mass flowmeter is communicated with the first mechanical pump, and the first mechanical pump is used for exhausting air from the air outlet end of the second mass flowmeter.
According to the high-precision constant pressure control device provided by the invention, the upper space of the piston pressure gauge is communicated with the second mechanical pump, and the second mechanical pump is used for exhausting the upper space of the piston pressure gauge.
A second aspect of the present invention provides a constant voltage control system comprising the high-precision constant voltage control device as described above.
The beneficial effects are that: the invention provides a high-precision constant pressure control device, which comprises a gas transmission pipeline, a first mass flowmeter, a second mass flowmeter, a piston pressure meter, a constant pressure cavity, a displacement sensor and a controller, wherein the gas transmission pipeline is arranged between the first mass flowmeter and the second mass flowmeter, the allowable passing gas flow value of the second mass flowmeter is smaller than that of the first mass flowmeter, the working gas flow difference generated between the first mass flowmeter and the second mass flowmeter enters a lower space of the piston pressure meter and the constant pressure cavity for use, the pressure of working gas entering the lower space of the piston pressure meter and the constant pressure cavity is stable through the pressure stabilization and the flow limitation of the first mass flowmeter and the second mass flowmeter, the gas pressure value measured by the piston pressure meter is equal to that in the constant pressure cavity, and the piston height measured by the displacement sensor is used as a feedback signal of pressure control for regulating the allowable passing gas flow value of the second mass flowmeter through the controller, so that the whole precision of the whole device is prevented from being influenced by the high-precision control of the pressure of the whole device.
Further, in the constant pressure control system provided by the present invention, since the high-precision constant pressure control device as described above is provided, various advantages as described above are also provided.
Drawings
In order to more clearly illustrate the invention or the technical solutions of the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the invention, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a high-precision constant voltage control device according to an embodiment of the present invention.
Reference numerals:
1. a gas transmission line; 2. a first mass flow meter; 3. a second mass flow meter; 4. a piston pressure gauge; 5. a constant pressure cavity; 6. a displacement sensor; 7. an auxiliary pipeline; 8. a first buffer cavity; 9. a first pressure sensor; 10. a second pressure sensor; 11. a three-way valve; 12. a four-way valve; 13. a first valve; 14. a gas cylinder; 15. a second valve; 16. a pressure reducing valve; 17. a second buffer cavity; 18. a first mechanical pump; 19. a second mechanical pump; 20. a vacuum pump; 21. and a temperature control box.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "horizontal", "inner", "outer", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent.
The constant pressure device is a device capable of providing stable pressure environment, is basic equipment required by some experimental environments, and is commonly used in the aspects of chemical reaction experiments, petrochemical industry fields, scientific experiments and the like.
The pressure control precision in the constant pressure device depends on the precision of the pressure gauge, the constant pressure device generally monitors the pressure by using a high-precision and high-stability piston pressure gauge, the piston pressure gauge comprises a cylinder body and a piston, the piston is slidably arranged in the cylinder body, the piston divides the cylinder body into an upper space and a lower space, the lower space is filled with working gas to be detected, a standard weight is placed in the upper space, and after the piston is in a balance position, the pressure control of the constant pressure device is performed according to the obtained pressure value as a feedback signal.
However, since a small gap exists between the piston and the cylinder of the piston pressure gauge, working gas in the lower space of the piston can leak and be lost through the gap, so that the pressure measured by the piston pressure gauge is unstable, and continuous pulse fluctuation of the gas pressure can occur in the process of transmitting the working gas, thereby affecting the pressure control precision of the constant pressure device.
In the embodiment of the invention, through setting the first mass flowmeter and the second mass flowmeter, setting the gas flow value allowed to pass by the second mass flowmeter to be smaller than the gas flow value allowed to pass by the first mass flowmeter, the working gas flow difference generated between the first mass flowmeter and the second mass flowmeter enters the lower space of the piston pressure gauge and the constant pressure cavity for use, and through stabilizing and limiting the pressure of the working gas entering the lower space of the piston pressure gauge and the constant pressure cavity by the first mass flowmeter and the second mass flowmeter, the working gas pressure entering the lower space of the piston pressure gauge and the constant pressure cavity is stable, the gas transmission pipelines between the lower space of the piston pressure gauge, the constant pressure cavity and the first mass flowmeter and the second mass flowmeter are communicated, the gas pressure is equal, the gas pressure value measured by the piston pressure gauge is the gas pressure value in the constant pressure cavity, and the gas flow value allowed to pass by the second mass flowmeter is regulated by the controller by taking the piston height measured by the displacement sensor as a feedback signal for pressure control, so that the working gas leakage of the lower space of the piston pressure gauge is prevented from influencing the pressure control precision of the whole device, and the pressure control precision of the whole device is improved.
The high-precision constant-pressure control device and system of the present invention are described below with reference to fig. 1.
As shown in fig. 1, the high-precision constant pressure control device provided by some embodiments of the present invention includes a gas transmission pipeline 1, a first mass flowmeter 2, a second mass flowmeter 3, a piston pressure gauge 4, a constant pressure cavity 5, a displacement sensor 6 and a controller, where the gas transmission pipeline 1 is used for transmitting working gas, the first mass flowmeter 2 and the second mass flowmeter 3 are sequentially arranged on the gas transmission pipeline 1 along the direction of gas transmission, at least the flow rate of gas allowed to pass through by the second mass flowmeter 3 is adjustable, and both the first mass flowmeter 2 and the second mass flowmeter 3 can measure the flow rate of gas actually passing through and also can set the flow rate allowed to pass through.
The piston pressure gauge 4 comprises a cylinder body and a piston, the piston is slidably arranged in the cylinder body, the piston divides the cylinder body into an upper space and a lower space, the gas transmission pipeline 1 between the first mass flowmeter 2 and the second mass flowmeter 3 is respectively communicated with the lower space of the piston pressure gauge 4 and the constant pressure cavity 5, and the air pressure in the lower space of the piston pressure gauge 4, the constant pressure cavity 5 and the gas transmission pipeline 1 are equal. In practical application, part of the gas transmission pipeline 1, the first mass flowmeter 2, the second mass flowmeter 3 and the piston pressure meter 4 are placed on the operation platform, so that the gas pressure between the two is stable, and the constant pressure cavity 5 can be of a cavity structure with various materials and shapes and can be applied to various constant pressure environments. The displacement sensor 6 is used for measuring the height of the piston, the piston height measured by the displacement sensor 6 is used as a feedback signal for pressure control, a laser displacement meter can be used for the displacement sensor 6, and a controller is electrically connected with the displacement sensor 6 and the second mass flowmeter 3 so as to adjust the flow rate of gas allowed to pass through the second mass flowmeter 3 according to the change of the height of the piston.
The first mass flowmeter 2 is used for controlling the gas flow entering the constant pressure cavity 5, the specific value can be set to a constant value in application, the specific value is adjusted according to the measurement range of the first mass flowmeter 2 and the second mass flowmeter 3, the measured pressure of the piston pressure meter 4, the required pressure of the constant pressure cavity 5 and other parameters, the second mass flowmeter 3 is used for controlling the gas flow flowing out of the constant pressure cavity 5, the allowable gas flow of the second mass flowmeter 3 is smaller than the allowable gas flow of the first mass flowmeter 2, the controller dynamically adjusts the allowable gas flow of the second mass flowmeter 3 according to the piston height signal of the piston pressure meter 4 fed back by the displacement sensor 6, and the allowable flow value of the second mass flowmeter 3 is always smaller than the allowable flow value of the first mass flowmeter 2 so as to maintain the stable pressure between the first mass flowmeter 2 and the second mass flowmeter 3, namely the sum of the lower space of the piston pressure meter 4, the constant pressure cavity 5 and the gas transmission pipeline 1 between the first mass flowmeter 2 and the second mass flowmeter 3 is the pressure difference between the first mass flowmeter 2 and the second mass flowmeter 3.
During operation, working gas enters the gas transmission pipeline 1 to be transmitted, enters the first mass flowmeter 2 to stabilize and limit the pressure of the working gas, then enters the lower space of the piston pressure gauge 4, the constant pressure cavity 5 and the second mass flowmeter 3 respectively, and because the flow allowed to pass through by the second mass flowmeter 3 is smaller than the flow allowed to pass through by the first mass flowmeter 2, the working gas intercepted between the first mass flowmeter 2 and the second mass flowmeter 3 is uniformly distributed in the lower space of the piston pressure gauge 4, the constant pressure cavity 5 and the gas transmission pipeline 1 between the first mass flowmeter 2 and the second mass flowmeter 3, the air pressures in the three are equal, after the working gas enters the lower space of the piston pressure gauge 4, the piston floats, and after the piston is at a balance position, the air pressure value measured by the piston pressure gauge 4 is the air pressure value in the constant pressure cavity 5. The height change of the piston can sensitively reflect the fluctuation of the gas pressure in the lower space of the piston, so that the height of the piston measured by the displacement sensor 6 is used as a feedback signal for pressure control, the controller adjusts the gas flow value of the second mass flowmeter 3 according to the feedback signal, the pressure control is carried out on the constant pressure cavity 5 by dynamically adjusting the gas flow value of the second mass flowmeter 3, the pressure in the constant pressure cavity 5 is kept constant, and meanwhile, the lifting and lowering of the piston pressure meter 4 compensates and buffers the pressure change of the lower space, so that the amplitude of the pressure change of the lower space can be reduced, and the pressure is stabilized.
In this embodiment, by setting the first mass flowmeter 2 and the second mass flowmeter 3, and setting the gas flow value allowed to pass through by the second mass flowmeter 3 to be smaller than the gas flow value allowed to pass through by the first mass flowmeter 2, the working gas flow difference generated between the first mass flowmeter 2 and the second mass flowmeter 3 enters the lower space of the piston pressure gauge 4 and the constant pressure cavity 5 for use, and through the pressure stabilization and the flow limitation of the first mass flowmeter 2 and the second mass flowmeter 3, the working gas pressure entering the lower space of the piston pressure gauge 4 and the constant pressure cavity 5 can be stabilized, and the gas transmission pipeline 1 between the lower space of the piston pressure gauge 4, the constant pressure cavity 5 and the first mass flowmeter 2 and the second mass flowmeter 3 is communicated, the gas pressure is equal, the gas pressure value measured by the piston pressure gauge 4 is the gas pressure value in the constant pressure cavity 5, and the piston height measured by the displacement sensor 6 is used as the feedback signal of the pressure control to regulate the allowed gas flow value of the second mass flowmeter 3, so that the whole pressure control accuracy and precision of the whole pressure control device are prevented from being influenced by the lower space of the piston pressure gauge 4.
Continuing to show in fig. 1, the high-precision constant pressure control device further comprises an auxiliary monitoring unit for assisting in monitoring the gas pressure in the constant pressure cavity 5, and a pressure measuring device is arranged on the auxiliary pipeline and used for measuring the pressure in the auxiliary pipeline. Specifically, the auxiliary monitoring unit includes an auxiliary pipeline 7 and a pressure measuring device, wherein the auxiliary pipeline 7 is communicated with the constant pressure cavity 5, the lower space of the piston pressure gauge 4 and the gas transmission pipeline 1 between the first mass flow meter 2 and the second mass flow meter 3, that is, the air pressures in the four are equal, the pressure measuring device measures the pressure in the auxiliary pipeline, which is equivalent to the pressure in the lower space of the piston pressure gauge 4 and the constant pressure cavity 5, and the pressure measuring device measures the pressure in real time so as to obtain higher pressure variation precision, and meanwhile, the pressure fluctuation condition in the pipeline can be reflected.
In order to further stabilize the air pressure variation in the pipeline, in some embodiments of the present invention, the auxiliary monitoring unit further includes a first buffer cavity 8 disposed on the auxiliary pipeline and located at the end of the auxiliary pipeline, i.e. the end far away from the piston pressure gauge 4, where the first buffer cavity 8 has a certain volume for stabilizing the air pressure in the pipeline and reducing the air pressure fluctuation, and the volume of the first buffer cavity 8 can be adjusted according to the disturbance of the air pressure in the pipeline and the actual air pressure fluctuation.
In order to improve the measurement accuracy of the pressure measuring device, in some embodiments of the present invention, the pressure measuring device includes a first pressure sensor 9 and a second pressure sensor 10, which are sequentially disposed on the auxiliary pipeline 7, and the first pressure sensor 9 is disposed close to the first buffer cavity 8, and the second pressure sensor 10 is disposed on a side of the first pressure sensor 9 away from the first buffer cavity 8, so as to avoid the inherent drift of the pressure measuring device over time, and the absolute value of the pressure measurement is not accurate.
In order to ensure the tightness of the communication among the lower space of the piston pressure gauge 4, the constant pressure cavity 5 and the gas transmission pipeline 1 between the first mass flowmeter 2 and the second mass flowmeter 3, in some embodiments of the present invention, a three-way valve 11 is arranged on the gas transmission pipeline 1 between the first mass flowmeter 2 and the second mass flowmeter 3, and the three-way valve 11 comprises a first end, a second end and a third end, wherein the first end is communicated with the air outlet end of the first mass flowmeter 2, the second end is communicated with the air inlet end of the second mass flowmeter 3, and the tightness of each connection point is improved by arranging the three-way valve 11.
In order to ensure the tightness of the communication between the auxiliary pipeline 7 and the constant pressure cavity 5, the lower space of the piston pressure gauge 4 and the gas transmission pipeline 1 between the first mass flowmeter 2 and the second mass flowmeter 3, in some embodiments of the present invention, a four-way valve 12 is further provided, wherein the four-way valve 12 comprises a fourth end, a fifth end, a sixth end and a seventh end, the fourth end is communicated with the third end of the three-way valve 11, the fifth end is communicated with the constant pressure cavity 5, the sixth end is communicated with the lower space of the piston pressure gauge 4, the seventh end is communicated with the auxiliary pipeline 7, and a first valve 13 is further provided between the seventh end and the auxiliary pipeline 7 for controlling the on-off between the four-way valve 12 and the auxiliary pipeline 7.
In some embodiments of the present invention, the constant pressure control device further includes a gas cylinder 14, the gas cylinder 14 stores high pressure working gas, the working gas includes but is not limited to any one of helium, argon, nitrogen and other simple substance gases or a mixed gas selected from any simple substance gases, the gas cylinder 14 is used as a gas source of the constant pressure control device, the gas cylinder 14 is connected with a second valve 15, the gas cylinder 14 is communicated with the gas transmission pipeline 1 through the second valve 15, the second valve 15 controls on-off between the gas cylinder 14 and the gas transmission pipeline 1, a pressure reducing valve 16 is further disposed between the second valve 15 and the first mass flowmeter 2, the pressure reducing valve 16 is disposed on the gas transmission pipeline 1 between the gas cylinder 14 and the first mass flowmeter 2, the pressure of the gas flowing out from the gas cylinder 14 can be reduced by the pressure reducing valve 16, the high pressure gas is prevented from directly impacting the first mass flowmeter 2, a second buffer cavity 17 is further disposed between the pressure reducing valve 16 and the first mass flowmeter 2, the second buffer cavity 17 is disposed on the gas transmission pipeline 1 between the pressure reducing valve 16 and the first mass flowmeter 2, and the pressure of the gas flowing out from the pressure reducing valve 16 can be buffered by the first mass flowmeter 2 is uniform.
In order to enable the working gas to smoothly flow out of the second mass flowmeter 3, in some embodiments of the present invention, the air outlet end of the second mass flowmeter 3 is communicated with the first mechanical pump 18, the first mechanical pump 18 is used for pumping the air outlet end of the second mass flowmeter 3, the first mechanical pump 18 can provide a low-pressure environment, so that the working gas smoothly flows out of the second mass flowmeter 3, and the pumping efficiency of the first mechanical pump 18 is set at 100 Pa to 400Pa, and more preferably 200Pa or 300Pa.
Because working gas in the lower space of the piston pressure gauge 4 leaks into the upper space through a gap between the piston and the cylinder, the weight of the standard weight is additionally increased, in order to maintain the vacuum degree of the upper space of the piston pressure gauge 4 and improve the measurement accuracy of the piston pressure gauge 4, in some embodiments of the present invention, the upper space of the piston pressure gauge 4 is communicated with the second mechanical pump 19, the upper space of the piston pressure gauge 4 is pumped by the second mechanical pump 19, and a vacuum pump 20 can be further arranged between the upper space of the piston pressure gauge 4 and the second mechanical pump 19, the vacuum pump 20 cooperates with the second mechanical pump 19, and the gas leaking into the upper space from the lower space in time maintains the high vacuum environment of the upper space of the piston pressure gauge 4, and maintains the air pressure of the upper space of the piston pressure gauge 4 at about 0.4 Pa.
In order to further improve the measurement accuracy of each component and reduce the influence of temperature variation on the measurement, the components which are easy to be influenced by temperature are all arranged in the temperature control box 21, and as a further preferable mode, for example, the first pressure sensor 9, the second pressure sensor 10, the piston pressure gauge 4, the displacement sensor 6, the first mass flowmeter 2, the second mass flowmeter 3, the second buffer cavity 17 and part of the gas transmission pipeline 1 can be arranged in the temperature control box 21, the temperature control box 21 can keep a stable set temperature so as to reduce the influence of temperature fluctuation on the working state of the instrument, the set temperature of the temperature control box 21 comprises but is not limited to 24.5 ℃, and the constant pressure cavity 5 can be arranged in a pressure stable experimental environment cavity, wherein the experimental environment cavity comprises but is not limited to room temperature, low temperature and extremely low temperature environment state.
In a second aspect, an embodiment of the present invention further provides a constant voltage control system, including the high-precision constant voltage control device provided in any one of the embodiments above. The derivation process of the beneficial effects of the constant voltage control system in the embodiment of the present invention is substantially similar to that of the high-precision constant voltage control device, so that the description thereof is omitted herein.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A high-precision constant-pressure control device, characterized by comprising:
a gas transmission line (1);
the first mass flowmeter (2) and the second mass flowmeter (3) are sequentially arranged on the gas transmission pipeline (1) along the gas transmission direction, and at least the gas flow allowed to pass by the second mass flowmeter (3) is adjustable;
a piston pressure gauge (4) comprising a cylinder and a piston slidably disposed within the cylinder, the piston dividing the cylinder into an upper space and a lower space;
a constant pressure cavity (5);
the gas transmission pipeline (1) between the first mass flowmeter (2) and the second mass flowmeter (3) is respectively communicated with the lower space of the piston pressure gauge (4) and the constant pressure cavity (5);
a displacement sensor (6) for measuring the height of the piston;
and the controller is electrically connected with the displacement sensor (6) and the second mass flowmeter (3) so as to adjust the gas flow allowed by the second mass flowmeter (3) according to the height change of the piston.
2. The high-precision constant pressure control device according to claim 1, further comprising:
an auxiliary monitoring unit comprising an auxiliary pipeline (7) and a pressure measuring device;
wherein the gas transfer line (1) between the first mass flowmeter (2) and the second mass flowmeter (3) is in communication with the auxiliary line (7);
the pressure measuring device is arranged on the auxiliary pipeline (7) and is used for measuring the pressure in the auxiliary pipeline (7).
3. The high-precision constant pressure control device according to claim 2, wherein the auxiliary monitoring unit further comprises a first buffer cavity (8) arranged on the auxiliary pipeline (7).
4. A high-precision constant pressure control apparatus according to claim 2 or 3, wherein the pressure measuring device comprises:
the first pressure sensor (9) and the second pressure sensor (10) are sequentially arranged on the auxiliary pipeline (7).
5. The high-precision constant pressure control device according to claim 2, characterized in that a three-way valve (11) is arranged on the gas transmission pipeline (1) between the first mass flowmeter (2) and the second mass flowmeter (3), and the three-way valve (11) comprises a first end, a second end and a third end;
wherein the first end is communicated with the air outlet end of the first mass flowmeter (2), and the second end is communicated with the air inlet end of the second mass flowmeter (3).
6. The high-precision constant pressure control device according to claim 5, further comprising:
a four-way valve (12), the four-way valve (12) comprising a fourth end, a fifth end, a sixth end, and a seventh end;
the fourth end is communicated with the third end of the three-way valve (11), the fifth end is communicated with the constant pressure cavity (5), the sixth end is communicated with the lower space of the piston pressure gauge (4), and the seventh end is communicated with the auxiliary pipeline (7).
7. The high-precision constant pressure control device according to claim 1, further comprising:
a gas cylinder (14) in communication with the gas transfer line (1);
a pressure reducing valve (16) arranged on the gas transmission pipeline (1) between the gas cylinder (14) and the first mass flowmeter (2);
and the second buffer cavity (17) is arranged on the gas transmission pipeline (1) between the pressure reducing valve (16) and the first mass flowmeter (2).
8. The high-precision constant pressure control device according to claim 1, wherein the air outlet end of the second mass flowmeter (3) is communicated with a first mechanical pump (18), and the first mechanical pump (18) is used for pumping air from the air outlet end of the second mass flowmeter (3).
9. The high-precision constant pressure control device according to claim 1 or 8, characterized in that the piston pressure gauge (4) upper space is in communication with a second mechanical pump (19), the second mechanical pump (19) being used for evacuating the piston pressure gauge (4) upper space.
10. A constant voltage control system comprising the high-precision constant voltage control device according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311540717.0A CN117389342A (en) | 2023-11-17 | 2023-11-17 | High-precision constant-voltage control device and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311540717.0A CN117389342A (en) | 2023-11-17 | 2023-11-17 | High-precision constant-voltage control device and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117389342A true CN117389342A (en) | 2024-01-12 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311540717.0A Pending CN117389342A (en) | 2023-11-17 | 2023-11-17 | High-precision constant-voltage control device and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117389342A (en) |
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2023
- 2023-11-17 CN CN202311540717.0A patent/CN117389342A/en active Pending
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