System and method for quantitatively filling and sealing natural gas in vacuum state

Abstract

The invention relates to a system and method for quantitatively filling and sealing natural gas in a vacuum state. The system comprises a gas inlet valve, a gas outlet valve, an evacuator, a constant-speed gas injection device, a clamping device, a sealing device and a first pressure sensor arranged in the constant-speed gas injection device. The outlet end of the air inlet valve is respectively connected with a constant-speed air injection device and an evacuator; the inlet end of the gas outlet valve is connected with the constant-speed gas injection device, and the outlet end of the gas outlet valve is connected with the gold kettle body; the vacuumizing device is used for vacuumizing the gold kettle body and the constant-speed gas injection device; the constant-speed gas injection device is used for opening the gas inlet valve after the constant-speed gas injection device is vacuumized so as to introduce the natural gas to be detected until a preset filling pressure is reached, and closing the gas inlet valve and opening the gas outlet valve so as to quantitatively fill the gold kettle body with the natural gas; the clamping device is used for clamping the gold kettle body and clamping the opening part of the gold kettle body after the gold kettle body is filled with natural gas to be detected. According to the invention, zero-loss and pollution-free filling and sealed storage of the natural gas to be detected are realized.

Description

Technical Field

[0001] The invention relates to a system and method for quantitatively charging and sealing natural gas under vacuum state. Background Art

[0002] As a clean, low-carbon, and environmentally friendly renewable energy source, natural gas is gradually becoming the primary source of incremental energy supply. Compared to oil, natural gas is buried deeper, experiences higher temperatures and pressures, and has a more complex origin. This makes it more difficult to capture scientific information about its true underground state and environment. Therefore, it is necessary to conduct laboratory studies on the generation dynamics of natural gas under high-temperature and high-pressure conditions to explore the sources, cracking mechanisms, and preservation limits of deep-seated natural gas, and to establish a lower limit for natural gas exploration depths. To conduct these studies on the generation dynamics of natural gas, innovative methods and devices for vacuum packaging of natural gas are needed. Summary of the Invention

[0003] In order to vacuum-pack natural gas and prevent it from being contaminated by external impurities, the present invention proposes a system and method for quantitatively filling and sealing natural gas under a vacuum state. The technical solutions proposed by the present invention are as follows:

[0004] In a first aspect, the present invention provides a system for quantitatively filling and sealing natural gas under a vacuum state, comprising: an inlet valve, an outlet valve, an evacuation device, a constant-rate gas injection device, a clamping device, a sealing device, and a first pressure sensor disposed in the constant-rate gas injection device;

[0005] The inlet end of the air inlet valve is used to introduce the natural gas to be tested, and the outlet end of the air inlet valve is connected to the constant-rate gas injection device and the evacuation device respectively;

[0006] The inlet end of the gas outlet valve is connected to the constant speed gas injection device, and the outlet end of the gas outlet valve is used to connect to the gold kettle body;

[0007] The vacuuming device is used to evacuate the gold kettle body and the constant-rate gas injection device to a vacuum;

[0008] The constant-rate gas injection device is used to open the gas inlet valve after vacuum is evacuated to allow the natural gas to be tested to enter until a preset filling pressure is reached, and to close the gas inlet valve and open the gas outlet valve to quantitatively fill the natural gas to be tested into the gold kettle;

[0009] The clamping device is used to clamp the gold kettle body and clamp the mouth of the gold kettle body after the gold kettle body is filled with the natural gas to be tested;

[0010] The sealing device is used to seal the mouth.

[0011] In one or some embodiments, the constant-rate gas injection device includes a housing, a pull rod, a cylinder, a servo motor, a screw, a piston, and a plug;

[0012] The servo motor is arranged at one end of the housing, and the other end of the housing is fixedly connected to the pull rod;

[0013] The cylinder is arranged in the pull rod;

[0014] The plug is arranged at one end of the cylinder away from the servo motor;

[0015] One end of the screw rod is connected to the servo motor, and the other end is connected to the piston;

[0016] The plug has a passage communicating with the cylinder;

[0017] The servo motor is used to drive the screw rod so that the screw rod drives the piston to move in the cylinder.

[0018] In one or some embodiments, the outlet end of the air inlet valve and the inlet end of the air outlet valve are respectively connected to the plug.

[0019] In one or some embodiments, the first pressure sensor is used to collect pressure data within the cylinder.

[0020] In one or some embodiments, the evacuation device includes an evacuation valve and a vacuum pump;

[0021] The evacuation valve is connected to the outlet end of the vacuum pump and the outlet end of the air inlet valve respectively.

[0022] In one or some embodiments, the constant rate gas injection device further comprises a bracket;

[0023] The bracket is fixedly connected to the pull rod and the shell respectively.

[0024] In one or some embodiments, the clamping device includes a housing, a base, a first actuator, a second actuator, and a third actuator;

[0025] The first actuator and the base are arranged relative to each other in the housing, and the second actuator and the third actuator are arranged relative to each other in the housing;

[0026] A fixing groove is provided on the top of the base;

[0027] The first actuator is capable of moving toward the base and clamping the middle portion of the gold kettle body;

[0028] The second actuating mechanism and the third actuating mechanism can move toward each other to clamp the mouth of the gold kettle body.

[0029] In one or some embodiments, the housing includes a vertical plate, a fixing portion, a top plate and a bottom plate that are oppositely arranged;

[0030] The top plate and the bottom plate are connected via the vertical plate;

[0031] The fixing portion is fixed to the top plate, the first actuator is fixed to the fixing portion, and the second actuator is fixed to a side surface of the first actuator;

[0032] The base is fixed to the bottom plate, and the third actuator is fixed to a side surface of the base.

[0033] In one or some embodiments, the system further comprises a second pressure sensor;

[0034] The second pressure sensor is arranged on the pipeline between the air outlet valve and the clamping device.

[0035] In a second aspect, the present invention provides a method for quantitatively charging and sealing natural gas under a vacuum state, comprising:

[0036] Use a clamping device to clamp the gold kettle body;

[0037] Start the constant-speed gas injection device and open the vacuum device to evacuate the interior of the gold kettle;

[0038] After a preset delay time, the evacuation device is closed and the air inlet valve is opened, so that the natural gas to be tested enters the constant-rate gas injection device under the action of the pressure difference;

[0039] Obtaining pressure data collected by the first pressure sensor, and when the pressure data reaches a preset filling pressure, closing the air inlet valve and opening the air outlet valve to allow the natural gas to be tested to be injected into the interior of the gold kettle;

[0040] The clamping device is used to clamp the mouth of the gold kettle body, and the sealing device is used to close the mouth.

[0041] Based on the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0042] The system for quantitatively filling and sealing natural gas under a vacuum state provided by the present invention can evacuate the gold kettle body to a vacuum state through a vacuuming device before filling the gold kettle body with natural gas, thereby ensuring that the natural gas is not contaminated by external impurities. After the gold kettle body is evacuated to a vacuum state, the constant-speed gas injection device is used to quantitatively fill the gold kettle body with the natural gas to be tested according to a preset filling pressure, thereby achieving quantitative filling of natural gas. After the natural gas to be tested is quantitatively filled into the gold kettle body, a clamping device is used to clamp the mouth of the gold kettle body to flatten it, and a sealing device is used to seal the mouth of the gold kettle body to achieve vacuum sealing of natural gas, thereby providing scientific researchers with feasible means and devices for analyzing the causes of natural gas and the critical conditions of natural gas cracking under high-temperature and high-pressure conditions in a laboratory environment.

[0043] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purposes and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 This is a schematic plan view of the entire process of a system for quantitatively charging and sealing natural gas under vacuum conditions provided by an embodiment of the present invention;

[0047] Figure 2 1 is a schematic structural diagram of a constant-rate gas injection device provided in an embodiment of the present invention;

[0048] Figure 3 is a schematic structural diagram of a clamping device provided by an embodiment of the present invention;

[0049] Figure 4a 1 is a side view of the clamping device provided by an embodiment of the present invention (initial position);

[0050] Figure 4b 1 is a side view of the clamping device provided by an embodiment of the present invention (pressing position);

[0051] In the figure: 1. Inlet valve; 2. Outlet valve; 3. Evacuation device; 301. Evacuation valve; 302. Vacuum pump; 4. Constant-speed gas injection device; 401. Housing; 402. Pull rod; 403. Cylinder; 404. Servo motor; 405. Screw; 406. Piston; 407. Plug; 5. Clamping device; 501. Top plate; 502. Vertical plate; 503. Bottom plate; 504. Fixing part; A. First actuator; B. Second actuator; C. Third actuator; D. Base; 6. Gold kettle body; 7. Sealing device; 8. First pressure sensor; 9. Second pressure sensor. DETAILED DESCRIPTION

[0052] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0053] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, like numbers in different figures represent like or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0054] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0055] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0056] As a clean, low-carbon, and environmentally friendly renewable energy source, natural gas is gradually becoming the primary source of incremental energy supply. Compared to oil, natural gas is buried deeper, experiences higher temperatures and pressures, and has a more complex origin. This makes it more difficult to capture scientific information about its true underground state and environment. Therefore, it is necessary to analyze the origin of natural gas and the critical conditions for its cracking under high-temperature and high-pressure laboratory conditions. This aims to explore the sources, cracking mechanisms, and preservation limits of deep-seated natural gas, establish a lower limit for natural gas exploration depth, and assist in improving basic natural gas geological theory. Ultimately, this research will guide the exploration and production of deep-seated natural gas.

[0057] The gold kettle is an important device for conducting hydrocarbon generation dynamics simulation experiments. The inventors found in their work that due to the limitations of packaging technology, the experiment is currently only applicable to solid or liquid samples (source rocks, kerogen, crude oil, etc.). The packaging operation process is to evacuate the gold kettle after loading the sample, and then weld and seal it under nitrogen protection. However, the closed sample loading method and device based on the above-mentioned packaging operation process are only applicable to solid or liquid samples, but not to gas samples such as natural gas. The main component of natural gas is methane. The density of natural gas is 0.7174Kg / m3 at 0°C and 1 atmosphere. 3 , with a relative density of 0.5548 (assuming the density of air is 1, the density of natural gas relative to air is 0.5548). Because natural gas has a lower density than both air and nitrogen, the aforementioned nitrogen protective environment, based on the principle of buoyancy, is completely ineffective for natural gas samples. This makes it impossible to load and seal the natural gas sample tightly, falling short of the inventors' expectations. Therefore, innovative methods and devices for vacuum packaging natural gas are needed. Further research and development led the inventors to the present invention.

[0058] Example 1

[0059] The embodiment of the present invention relates to a system for automatic gas injection in a hydrocarbon generation kinetics simulation device, specifically providing a system for quantitatively filling and sealing natural gas under vacuum conditions. The principle is to use a vacuum-capable pressure vessel, namely a constant-rate gas injection device 4, as an intermediate device to inject natural gas into a gold kettle 6 and seal it in an environment free from external impurities. Figure 1 As shown, the system includes: an air inlet valve 1, an air outlet valve 2, an evacuation device 3, a constant-speed air injection device 4, a clamping device 5, a sealing device 7, and a first pressure sensor 8 provided in the constant-speed air injection device 4;

[0060] The inlet end of the air inlet valve 1 is used to introduce the natural gas to be tested, and the outlet end of the air inlet valve 1 is connected to the constant-speed gas injection device 4 and the evacuation device 3 respectively;

[0061] The inlet end of the gas outlet valve 2 is connected to the constant speed gas injection device 4, and the outlet end of the gas outlet valve 2 is used to connect to the gold kettle body 6;

[0062] The vacuuming device 3 is used to evacuate the gold kettle body 6 and the constant-rate gas injection device 4 to a vacuum;

[0063] The constant-rate gas injection device 4 is used to open the gas inlet valve 1 after vacuum is evacuated to allow the natural gas to be tested to enter until a preset filling pressure is reached, and to close the gas inlet valve 1 and open the gas outlet valve 2 to quantitatively fill the natural gas to be tested into the gold kettle 6;

[0064] The clamping device 5 is used to clamp the gold kettle 6 and clamp the mouth of the gold kettle 6 after the gold kettle 6 is filled with the natural gas to be tested;

[0065] The sealing device 7 is used to seal the mouth.

[0066] The constant-rate gas injection device 4 is an automatic control device with a built-in touch screen, on which the gas injection pressure (i.e., the preset filling pressure Pg) can be set. The natural gas pipeline to be tested is connected to the inlet of the inlet valve 1, and the outlet of the outlet valve 2 is connected to the gold kettle 6. When the constant-rate gas injection device 4 is activated, it automatically opens the evacuation device 3, evacuating all pipelines, the constant-rate gas injection device 4, and the interior of the gold kettle 6. After a preset delay, the evacuation device 3 automatically closes, and the inlet valve 1 is then opened. The natural gas to be tested enters the constant-rate gas injection device 4 under the action of a pressure differential. The first pressure sensor 8 measures the internal pressure of the constant-rate gas injection device 4 and automatically feeds this information back to the servo controller of the constant-rate gas injection device 4. The servo controller controls the operation of the constant-rate gas injection device 4, ultimately stabilizing the internal pressure of the constant-rate gas injection device 4 at the preset filling pressure. After the internal pressure of the constant-rate gas injection device 4 stabilizes at the preset filling pressure, the gas inlet valve 1 is closed and the gas outlet valve 2 is opened, so that the natural gas to be tested is filled into the gold kettle 6 at a preset flow rate. The gas injection volume can be automatically calculated based on the above-mentioned preset filling pressure Pg according to the gas balance equation.

[0067] The outlet valve 2 is a steady-flow valve, allowing the natural gas to be tested to flow into the interior of the gold kettle 6 at a set flow rate. The sealing device 7 is used to seal the gold kettle 6 and can be a welding device, specifically a pulsed argon arc welder. After the gold kettle 6 is filled with the natural gas to be tested, the clamping device 5 is used to clamp the gold kettle 6 and tighten the mouth of the gold kettle 6 to flatten it. After the excess portion at the front of the gold kettle 6 is trimmed with scissors, the mouth of the gold kettle 6 is sealed using the welding device.

[0068] The embodiment of the present invention provides a system for quantitatively filling and sealing natural gas under a vacuum state. Before filling the gold kettle 6 with natural gas, the gold kettle 6 can be evacuated to a vacuum by the vacuuming device 3 to ensure that the natural gas is not contaminated by external impurities. After the gold kettle 6 is evacuated to a vacuum, the constant speed gas injection device 4 is used to quantitatively fill the gold kettle 6 with the natural gas to be tested according to the preset filling pressure, thereby achieving quantitative filling of natural gas. After the gold kettle 6 is quantitatively filled with the natural gas to be tested, the clamping device 5 is used to clamp the mouth of the gold kettle 6 to flatten it, and the sealing device 7 is used to seal the mouth of the gold kettle 6. The present invention realizes zero-loss, pollution-free filling and sealed storage of the natural gas to be tested into the gold kettle 6, providing a feasible means and device for scientific researchers to analyze the causes of natural gas and the critical conditions of natural gas cracking under high temperature and high pressure conditions in a laboratory environment.

[0069] In an alternative embodiment, referring to Figure 2 As shown, the constant-speed gas injection device 4 includes a housing 401, a pull rod 402, a cylinder 403, a servo motor 404, a screw 405, a piston 406 and a plug 407;

[0070] The servo motor 404 is disposed at one end of the housing 401 , and the other end of the housing 401 is fixedly connected to the pull rod 402 ;

[0071] The cylinder 403 is disposed inside the pull rod 402;

[0072] The plug 407 is provided at one end of the cylinder 403 away from the servo motor 404;

[0073] One end of the screw rod 405 is connected to the servo motor 404, and the other end is connected to the piston 406;

[0074] The plug 407 has a passage that communicates with the cylinder 403 , and the natural gas to be tested can enter and exit the cylinder 403 through the passage.

[0075] The servo motor 404 is used to drive the screw rod 405 , so that the screw rod 405 drives the piston 406 to move in the cylinder 403 .

[0076] The first pressure sensor 8 is used to collect pressure data within the cylinder 403. When the inlet valve 1 is opened and the natural gas to be tested enters the cylinder 403 of the constant-rate gas injection device 4, the first pressure sensor 8 measures the internal pressure of the cylinder 403 and automatically feeds it back to the servo controller of the servo motor 404. The piston 406 automatically retracts under the action of the servo motor 404 until the internal pressure of the constant-rate gas injection device 4 stabilizes at the preset filling pressure. When the internal pressure of the constant-rate gas injection device 4 stabilizes at the preset filling pressure, it automatically feeds back to the servo controller of the servo motor 404, closing the inlet valve 1 and opening the outlet valve 2. Driven by the servo motor 404, the screw 405 drives the piston 406 toward the plug 407, allowing the natural gas to be tested to be filled into the interior of the gold kettle 6 through the outlet valve 2 at the preset flow rate.

[0077] In an optional embodiment, the outlet end of the air inlet valve 1 and the inlet end of the air outlet valve 2 are respectively connected to the plug 407.

[0078] The above-mentioned inlet valve 1 and outlet valve 2 are both electrically controlled valves. When the natural gas to be tested is filled into the constant-speed gas injection device 4, the inlet valve 1 is opened and the outlet valve 2 is closed. The natural gas to be tested enters the cylinder 403 through the inlet valve 1 and the plug 407. When the pressure data in the cylinder 403 reaches the preset filling pressure, the inlet valve 1 is closed and the outlet valve 2 is opened. The natural gas to be tested in the cylinder 403 enters the gold kettle 6 through the plug 407 and the outlet valve 2.

[0079] In an alternative embodiment, referring to Figure 1 As shown, the evacuation device 3 includes an evacuation valve 301 and a vacuum pump 302;

[0080] The evacuation valve 301 is connected to the outlet end of the vacuum pump 302 and the air inlet valve 1 respectively;

[0081] The vacuum pump 302 is used to evacuate all pipelines, the constant-rate gas injection device 4 and the gold kettle 6 to a vacuum state, thereby facilitating the subsequent injection of natural gas into the gold kettle 6 under a vacuum environment and ensuring that the injected natural gas to be tested is not contaminated.

[0082] In this embodiment of the present invention, the system further includes a four-way valve, three of whose ports are connected to one end of the inlet valve 1, outlet valve 2, and evacuation valve 301, respectively. The fourth port of the four-way valve is connected to a plug 407. The other end of the inlet valve 1 is connected to the natural gas to be tested, the other end of the outlet valve 2 is connected to the gold kettle 6, and the other end of the evacuation valve 301 is connected to the vacuum pump 302.

[0083] In an alternative embodiment, referring to Figure 2 As shown, the constant-speed gas injection device 4 further includes a bracket;

[0084] The bracket is fixedly connected to the pull rod 402 and the housing 401 respectively.

[0085] The bracket can support the rod 402 and the housing 401 to improve the overall stability of the constant-rate gas injection device 4. At the same time, the height of the rod 402 and the housing 401 can be adjusted according to the position of the gold kettle 6 to facilitate the injection of the natural gas to be tested into the gold kettle 6.

[0086] In an alternative embodiment, referring to Figure 3 、 Figure 4a and 4b As shown, the clamping device 5 includes a housing, a base D, a first actuator A, a second actuator B and a third actuator C;

[0087] The first actuator A and the base D are arranged relative to each other in the housing, and the second actuator B and the third actuator C are arranged relative to each other in the housing;

[0088] A fixing groove is provided on the top of the base D;

[0089] The first actuator A can move toward the base D and clamp the middle of the gold kettle 6;

[0090] The second actuator B and the third actuator C can move toward each other to clamp the mouth of the gold kettle body 6.

[0091] The clamping device 5 may be equipped with a clamping button for controlling the operation of the first, second, and third actuators A, B, and C. When injecting the natural gas to be tested into the gold kettle 6, the clamping button on the panel of the clamping device 5 can be clicked, causing the first, second, and third actuators A, B, and C to simultaneously operate, tightly clamping the gold kettle 6 according to a set stroke and maintaining its central position. This allows the gold kettle 6 to be secured during the injection of the natural gas to be tested. After the injection of the natural gas to be tested, the clamping button can be clicked again, causing the second and third actuators B and C to continue to operate according to the set stroke, clamping the mouth of the gold kettle 6 and flattening it for later closure. The first actuator A presses the gold kettle 6 tightly against the base D, creating a seal. Under the action of a time delay relay, the second and third actuators B and C reset after a preset time (moving upward and downward, respectively), leaving their clamped positions, while the first actuator A remains in its clamped position. The first actuator A, the second actuator B and the third actuator C are devices capable of outputting a displacement corresponding to a control signal, such as electric cylinders.

[0092] In an alternative embodiment, referring to Figure 4a and 4bAs shown, the housing includes a vertical plate 502, a fixing portion 504, a top plate 501 and a bottom plate 503 that are oppositely arranged;

[0093] The top plate 501 and the bottom plate 503 are connected via the vertical plate 502;

[0094] The fixing portion 504 is fixed to the top plate 501 , the first actuator A is fixed to the fixing portion 504 , and the second actuator B is fixed to a side surface of the first actuator A;

[0095] The base D is fixed to the bottom plate 503 , and the third actuator C is fixed to a side surface of the base D.

[0096] The top plate 501 and bottom plate 503 are effectively connected using the vertical plate 502. The base D is fixed to the bottom plate 503, and the third actuator C is fixed to the side of the base D. The first actuator A and the second actuator B are integrally fixed to the top plate 501 by means of the fixing portion 504. Compared to directly fixing the second actuator B to the top plate 501 and the third actuator C to the bottom plate 503, fixing the second actuator B to the side of the first actuator A and the third actuator C to the side of the base D shortens the travel of the second and third actuators B and C during operation. The second and third actuators B and C can move toward each other with a short distance to clamp the mouth of the gold cauldron 6.

[0097] In an alternative embodiment, referring to Figure 1 As shown, the system further includes a second pressure sensor 9;

[0098] The second pressure sensor 9 is arranged on the pipeline between the air outlet valve 2 and the clamping device 5 .

[0099] By providing a second pressure sensor 9 in the pipeline between the gas outlet valve 2 and the clamping device 5, the gas pressure in the gold kettle 6 can be obtained when the gold kettle 6 is evacuated. The evacuation is performed according to the gas pressure to achieve vacuumization of the gold kettle 6, which facilitates the injection of the natural gas to be tested into the gold kettle 6 and ensures that the injected natural gas to be tested is not contaminated.

[0100] To more clearly illustrate the device for quantitatively filling and sealing natural gas under vacuum provided by an embodiment of the present invention, the following describes the entire process of using the device to fill a gold kettle 6 with natural gas to be tested. The complete device usage process includes four steps: pre-filling preparation, filling the gold kettle 6 with gas, clamping and welding the gold kettle 6, and calculating the natural gas quantity.

[0101] 1. Preparation before filling: Connect the natural gas pipeline to be tested to the inlet end of the air inlet valve 1, then place the gold kettle body 6 in the fixed groove on the base D, and use a special rubber tube with a length (L1) of 2cm and an inner diameter (R1) of 5mm to connect the gold kettle body 6 and the outlet end of the air outlet valve 2.

[0102] 2. Gas injection process of the gold kettle 6: Power on the system, and the first actuator A, the second actuator B and the third actuator C are all in the initial position (see Figure 4a Click the clamp button on the panel of clamping device 5, and the first, second, and third actuators A and C will simultaneously activate, tightly clamping the gold kettle 6 according to the set stroke and maintaining its center position. The second and third actuators B and C will clamp the mouth of the gold kettle 6, while the first actuator A will press the gold kettle 6 against the base D. Turn on the power of the constant-rate gas injection device 4, set the preset filling pressure Pg, and start the constant-rate gas injection device 4. The constant-rate gas injection device 4 automatically opens the evacuation valve 301 and starts the vacuum pump 302, evacuating all pipelines and the interior of the gold kettle 6. After a preset delay, the evacuation valve 301 and vacuum pump 302 are closed, and the inlet valve 1 is opened. The natural gas to be tested enters the constant-rate gas injection device 4 under the action of the pressure differential. The first pressure sensor 8 measures the pressure inside the cylinder 403 and automatically feeds it back to the servo controller of the servo motor 404. The piston 406 automatically retracts under the action of the servo motor 404 until the pressure inside the constant-rate gas injection device 4 stabilizes at the preset filling pressure Pg. The inlet valve 1 is closed, and the outlet valve 2 is opened, allowing the natural gas to be tested to be filled into the gold kettle 6 at the set flow rate.

[0103] 3. Gold kettle body 6 clamping and sealing welding process: Click the clamping button on the clamping device 5 panel, refer to Figure 4b As shown, the second and third actuators B and C operate simultaneously. According to the set stroke, they clamp the mouth of the gold kettle 6, flattening it to facilitate subsequent welding while maintaining the central position of the gold kettle 6. Under the action of the time delay relay, the second and third actuators B and C reset (moving upward and downward, respectively) after a preset time, leaving the clamped position, while the first actuator A remains in the clamped position. After using scissors to trim the excess portion of the front end of the gold kettle 6, the clamped portion of the second and third actuators B and C remains. Argon arc welding is used to ensure the tightness of the gold kettle 6. After welding is complete, the clamping button is pressed again, causing the first actuator A to reset upward, leaving the clamped position, and the gold kettle 6 to be removed. This concludes the entire process of vacuum-filling and sealing the gold kettle 6 with natural gas.

[0104] 4. Calculation of gas injection volume: The volume of natural gas injected into the gold kettle 6, i.e., the gas injection volume, can be calculated based on the injected natural gas pressure. According to the ideal gas state equation, the calculation formula is:

[0105] Vg=nR*T / Pg

[0106] Where Pg is the preset filling pressure, i.e., the injected natural gas pressure; Vg is the injected gas volume; n is the amount of natural gas (taking methane as an example, 45 mol at normal pressure); R is the ideal gas constant (approximately 8.314 J / (mol·K)); and T is the absolute temperature of the gas (unit: K, approximately 298K at normal temperature).

[0107] Example 2

[0108] An embodiment of the present invention provides a method for quantitatively charging and sealing natural gas under a vacuum state, comprising:

[0109] Use a clamping device 5 to clamp the gold kettle body 6;

[0110] Start the constant-speed gas injection device 4 and open the evacuation device 3 to evacuate the interior of the gold kettle 6;

[0111] After a preset delay, the evacuation device 3 is closed, and the air inlet valve 1 is opened, so that the natural gas to be tested enters the constant-rate gas injection device 4 under the action of the pressure difference;

[0112] Obtain pressure data collected by the first pressure sensor 8. When the pressure data reaches a preset filling pressure, close the air inlet valve 1 and open the air outlet valve 2 to allow the natural gas to be tested to be injected into the gold kettle 6.

[0113] The clamping device 5 is used to clamp the mouth of the gold kettle body 6, and the sealing device 7 is used to seal the mouth.

[0114] In the embodiment of the present invention, the method for quantitatively charging and sealing natural gas under a vacuum state corresponds to the system for quantitatively charging and sealing natural gas under a vacuum state described in the first embodiment. The specific implementation process can refer to the process of charging and sealing natural gas using the system for quantitatively charging and sealing natural gas under a vacuum state in the first embodiment. The repeated parts will not be repeated here.

[0115] In this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article or apparatus. The orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0116] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention is not limited to any single aspect, nor to any single embodiment, nor to any combination and / or permutation of these aspects and / or embodiments. Each aspect and / or embodiment of the present invention can be used alone or in combination with one or more other aspects and / or other embodiments.

[0117] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A system for quantitatively filling and sealing natural gas under vacuum conditions, characterized in that: include: An air inlet valve, an air outlet valve, an evacuation device, a constant-rate air injection device, a clamping device, a sealing device, and a first pressure sensor disposed in the constant-rate air injection device; The inlet end of the air inlet valve is used to introduce the natural gas to be tested, and the outlet end of the air inlet valve is connected to the constant-rate gas injection device and the evacuation device respectively; The inlet end of the gas outlet valve is connected to the constant speed gas injection device, and the outlet end of the gas outlet valve is used to connect to the gold kettle body; The vacuuming device is used to evacuate the gold kettle body and the constant-rate gas injection device to a vacuum; The constant-rate gas injection device is used to open the gas inlet valve after vacuum is evacuated to allow the natural gas to be tested to enter until a preset filling pressure is reached, and to close the gas inlet valve and open the gas outlet valve to quantitatively fill the natural gas to be tested into the gold kettle; The clamping device is used to clamp the gold kettle body and clamp the mouth of the gold kettle body after the gold kettle body is filled with the natural gas to be tested; The sealing device is used to seal the mouth.

2. The system for quantitatively filling and sealing natural gas under vacuum state according to claim 1, characterized in that: The constant-speed gas injection device comprises a housing, a pull rod, a cylinder, a servo motor, a screw rod, a piston and a plug; The servo motor is arranged at one end of the housing, and the other end of the housing is fixedly connected to the pull rod; The cylinder is arranged in the pull rod; The plug is arranged at one end of the cylinder away from the servo motor; One end of the screw rod is connected to the servo motor, and the other end is connected to the piston; The plug has a passage communicating with the cylinder; The servo motor is used to drive the screw rod so that the screw rod drives the piston to move in the cylinder.

3. The system for quantitatively filling and sealing natural gas under vacuum state according to claim 2, characterized in that: The outlet end of the air inlet valve and the inlet end of the air outlet valve are connected to the plugs respectively.

4. The system for quantitatively charging and sealing natural gas under vacuum state according to claim 3, characterized in that: The first pressure sensor of the constant-rate gas injection device is used to collect pressure data in the cylinder.

5. The system for quantitatively charging and sealing natural gas under vacuum state according to claim 1, characterized in that: The evacuation device includes an evacuation valve and a vacuum pump; The evacuation valve is connected to the outlet end of the vacuum pump and the outlet end of the air inlet valve respectively.

6. The system for quantitatively charging and sealing natural gas under vacuum state according to claim 3, characterized in that: The constant-rate gas injection device further includes a bracket; The bracket is fixedly connected to the pull rod and the shell respectively.

7. The system for quantitatively charging and sealing natural gas under vacuum state according to claim 1, characterized in that: The clamping device includes a housing, a base, a first actuator, a second actuator and a third actuator; The first actuator and the base are arranged relative to each other in the housing, and the second actuator and the third actuator are arranged relative to each other in the housing; A fixing groove is provided on the top of the base; The first actuator is capable of moving toward the base and clamping the middle portion of the gold kettle body; The second actuating mechanism and the third actuating mechanism can move toward each other to clamp the mouth of the gold kettle body.

8. The system for quantitatively charging and sealing natural gas under vacuum state according to claim 7, characterized in that: The shell includes a vertical plate, a fixing portion, a top plate and a bottom plate that are oppositely arranged; The top plate and the bottom plate are connected via the vertical plate; The fixing portion is fixed to the top plate, the first actuator is fixed to the fixing portion, and the second actuator is fixed to a side surface of the first actuator; The base is fixed to the bottom plate, and the third actuator is fixed to a side surface of the base.

9. The system for quantitatively charging and sealing natural gas under vacuum state according to claim 1, characterized in that: The system also includes a second pressure sensor; The second pressure sensor is arranged on the pipeline between the air outlet valve and the clamping device.

10. A method for quantitatively filling and sealing natural gas under vacuum conditions, characterized in that: include: Use a clamping device to clamp the middle part of the gold kettle; Start the constant-speed gas injection device and open the vacuum device to evacuate the interior of the gold kettle; After a preset delay time, the evacuation device is closed and the air inlet valve is opened, so that the natural gas to be tested enters the constant-rate gas injection device under the action of the pressure difference; Obtaining pressure data collected by the first pressure sensor, and when the pressure data reaches a preset filling pressure, closing the air inlet valve and opening the air outlet valve to allow the natural gas to be tested to be injected into the interior of the gold kettle; The clamping device is used to clamp the mouth of the gold kettle body, and the sealing device is used to close the mouth.

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