Mixed gas filling system and method

Abstract

The invention relates to the technical field of gas filling, in particular to a mixed gas filling system and method. The mixed gas filling system provided by the invention can reasonably utilize gas in gas source gas cylinders, and specifically comprises at least two gas source gas cylinders, a filled gas cylinder and at least two groups of pressure multiplication devices, and each gas source gas cylinder is connected with the filled gas cylinder through one group of pressure multiplication devices. And the pressure multiplication device is used for pressurizing the component gas with the fixed volume from the gas source gas cylinder by a preset multiple in a hydraulic manner, and filling the pressurized high-pressure gas into the filled gas cylinder.

Description

Technical Field

[0001] The present invention relates to the technical field of gas filling, and in particular to a system and method for filling a mixed gas. Background Art

[0002] The filling of mixed gas usually connects the source gas cylinder containing the component gas directly to the filled gas cylinder, and the filling is carried out in a pressure-equalizing manner. As the pressure of the source gas cylinder gradually decreases, the pressure in the filled gas cylinder gradually increases. When the pressure of the filled gas cylinder approaches the pressure of the source gas cylinder, not only the filled gas cylinder cannot continue to increase the pressure for filling, but also the gas in the source gas cylinder with a slightly lower pressure is difficult to continue to use. Summary of the invention

[0003] The invention provides a mixed gas filling system and method, which can reasonably utilize the gas in a gas source cylinder.

[0004] In one embodiment, the present invention provides a mixed gas filling system, comprising at least two gas source cylinders, a gas cylinder to be filled and at least two sets of pressure multiplying devices, each of the gas source cylinders being connected to the gas cylinder to be filled via a set of the pressure multiplying devices, the pressure multiplying devices being used to hydraulically pressurize a fixed volume of component gas from the gas source cylinder to a preset multiple, and fill the pressurized high-pressure gas into the gas cylinder to be filled.

[0005] Preferably, the pressure multiplier device includes a pressure multiplier and a liquid storage tank, the pressure multiplier is connected to the gas source cylinder and the liquid storage tank respectively, the liquid storage tank is used to store liquid, the high-pressure end of the pressure multiplier is used to accommodate a fixed volume of component gas from the gas source cylinder, and the low-pressure end is used to accommodate liquid from the liquid storage tank, and the pressure multiplier is used to pressurize the component gas at the high-pressure end by a preset multiple using the liquid at the low-pressure end.

[0006] Preferably, the pressure multiplier device also includes a valve group and a pump group, and the pressure multiplier is provided with a high-pressure end piston, a piston rod and a low-pressure end piston connected in sequence, the diameter of the high-pressure end piston is smaller than the diameter of the low-pressure end piston, and an intermediate cavity is formed between the high-pressure end piston and the low-pressure end piston, and a high-pressure cavity for accommodating component gases is formed on the side of the high-pressure end piston away from the intermediate cavity, and a low-pressure cavity is formed on the side of the low-pressure end piston away from the intermediate cavity, the intermediate cavity is connected to the valve group through a first pipeline, and the low-pressure cavity is connected to the valve group through a second pipeline, and the valve group is connected to the liquid storage tank through a liquid supply pipeline and a liquid return pipeline respectively, the pump group is arranged on the liquid supply pipeline, and the valve group is used to control the flow direction of the liquid in the first pipeline and the second pipeline.

[0007] Preferably, the gas source cylinder is connected to the high-pressure chamber via a third pipeline, and a pressure reducing device and a first one-way valve are provided on the third pipeline. The pressure reducing device is used to reduce the pressure of the gas source cylinder to a preset pressure so that a fixed volume of component gas is stored in the high-pressure chamber before filling.

[0008] Preferably, the high-pressure chamber is connected to the filled gas cylinder through a fourth pipeline, and a first pressure detection device and a second one-way valve are provided on the fourth pipeline, the first pressure detection device is used to detect the real-time pressure of the filled gas cylinder during the gas filling process, and a second pressure detection device is provided on the liquid supply pipeline, and the second pressure detection device is used to detect the real-time total pressure of the low-pressure chamber during the gas filling process.

[0009] Preferably, a vacuum pump is further included, which is connected to the fourth pipeline and is used to evacuate the third pipeline, the fourth pipeline, the filled gas cylinder and the high-pressure chamber before the first gas filling.

[0010] Preferably, the outlet of the vacuum pump, the outlet of the gas source cylinder and the inlet of the filled gas cylinder are all provided with valves, and the liquid return pipeline is provided with a heat exchanger and an air filter.

[0011] Preferably, the working pressure of the second one-way valve is 10 to 100 times the working pressure of the first one-way valve.

[0012] Preferably, gas filling is completed by controlling the real-time total pressure of the low-pressure chamber to satisfy the following target formula:

[0013] P l ≥R g ·P g ·A2÷A1

[0014] Where P l is the real-time total pressure of the low-pressure chamber, R g is a preset gas pressure increase ratio, which is the ratio of the fixed volume to the volume of the component gas after being compressed in the high-pressure chamber, P g is the preset pressure, A2 is the area of ​​the high-pressure end piston, and A1 is the area of ​​the low-pressure end piston.

[0015] In another embodiment, the present invention provides a method for filling a mixed gas. Based on the mixed gas filling system described in the above embodiment, the method includes:

[0016] Before gas filling, the component gas of the gas source cylinder is decompressed to the preset pressure by the decompression device and then filled into the high-pressure cavity. At this time, the volume of the high-pressure cavity is the fixed volume;

[0017] When gas filling is performed, the real-time total pressure of the low-pressure chamber is controlled to satisfy the target formula, so that the component gas in the high-pressure chamber is filled into the filled gas cylinder.

[0018] Beneficial effects:

[0019] The mixed gas filling system and method provided by the present invention, by arranging a pressure multiplying device between the gas source cylinder and the gas cylinder to be filled, can utilize the pressure multiplying device to hydraulically pressurize the component gases of a fixed volume from the gas source cylinder by a preset multiple, and fill the pressurized high-pressure gas into the gas cylinder to be filled, thereby solving the problems caused by filling mixed gas cylinders with gas source cylinders. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0021] Figure 1 A schematic structural diagram of a mixed gas filling system according to an embodiment is shown. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", "middle" and the like appear to indicate directions or positional relationships, they are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the product of the invention is usually placed when in use. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0026] like Figure 1 As shown, the present invention provides a mixed gas filling system, comprising at least two gas source cylinders 1, a filled gas cylinder 2 and at least two sets of pressure multiplying devices 3, each gas source cylinder 1 is connected to the filled gas cylinder 2 through a set of pressure multiplying devices 3, and the pressure multiplying devices 3 are used to pressurize the fixed volume of component gas from the gas source cylinder 1 by a preset multiple by hydraulic means, and fill the pressurized high-pressure gas into the filled gas cylinder 2.

[0027] The pressure multiplier 3 is based on Pascal's law. According to Pascal's law, when a certain pressure is applied to a piston in a hydraulic system, the force generated will inevitably transmit the same force to the piston through the piston rod; if the area of ​​one end of the piston rod is half of the area of ​​the piston at the other end, then the pressure acting on the piston at the other end will increase to twice that of the original piston.

[0028] For systems with gas, due to the compressibility of gas, how to use the pressure multiplier 3 is a problem worth studying. Considering the economy, using a pressure multiplier to complete the filling of mixed gas cylinders involves solving problems in processes, equipment and methods, and it is necessary to propose a system for filling mixed gases that is both economical and safe.

[0029] In this embodiment, by setting a pressure multiplying device 3 between the gas source cylinder 1 and the gas cylinder to be filled 2, the pressure multiplying device 3 can be used to hydraulically pressurize the component gas of a fixed volume from the gas source cylinder 1 to a preset multiple, and the pressurized high-pressure gas can be filled into the gas cylinder to be filled 2, thereby solving the problem caused by filling a mixed gas cylinder with a gas source cylinder.

[0030] In one embodiment, the pressure multiplier device 3 includes a pressure multiplier 31 and a liquid storage tank 32. The pressure multiplier 31 is connected to the gas source cylinder 1 and the liquid storage tank 32 respectively. The liquid storage tank 32 is used to store liquid. The high-pressure end of the pressure multiplier 31 is used to accommodate a fixed volume of component gas from the gas source cylinder 1, and the low-pressure end is used to accommodate liquid from the liquid storage tank 32. The pressure multiplier 31 is used to use the liquid at the low-pressure end to pressurize the component gas at the high-pressure end by a preset multiple.

[0031] The liquid may be water, hydraulic oil or other liquid media, which are not limited here.

[0032] In one embodiment, the pressure multiplier device 3 also includes a valve group 33 and a pump group 34. The pressure multiplier 31 is provided with a high-pressure end piston, a piston rod and a low-pressure end piston connected in sequence. The diameter of the high-pressure end piston is smaller than the diameter of the low-pressure end piston. An intermediate cavity is formed between the high-pressure end piston and the low-pressure end piston. The side of the high-pressure end piston away from the intermediate cavity forms a high-pressure cavity for accommodating component gases, and the side of the low-pressure end piston away from the intermediate cavity forms a low-pressure cavity. The intermediate cavity is connected to the valve group 33 through a first pipeline 41, and the low-pressure cavity is connected to the valve group 33 through a second pipeline 42. The valve group 33 is connected to the liquid storage tank 32 through a liquid supply pipeline 45 and a liquid return pipeline 46 respectively. The pump group 34 is arranged on the liquid supply pipeline 45, and the valve group 33 is used to control the flow direction of the liquid in the first pipeline 41 and the second pipeline 42.

[0033] When the two pistons move with the cylinder body outside them, three cavities are formed, namely the upper cavity (i.e. the high-pressure cavity), the middle cavity (i.e. the intermediate cavity) and the lower cavity (i.e. the low-pressure cavity). By using the pipelines connected to these three cavities and cooperating with the corresponding valves (i.e. the valve group), not only the entry and discharge of liquids in different cavities can be realized, but also the movement of the piston can be realized to realize reciprocating motion, thereby continuously pressurizing the component gas to be pressurized.

[0034] In one embodiment, the gas source cylinder 1 is connected to the high-pressure chamber through a third pipeline 43, and a pressure reducing device 51 and a first one-way valve 52 are provided on the third pipeline 43. The pressure reducing device 51 is used to reduce the pressure of the gas source cylinder 1 to a preset pressure so that a fixed volume of component gas is stored in the high-pressure chamber before filling.

[0035] In this embodiment, by providing a pressure reducing device 51, it can be ensured that a fixed volume of component gas is stored in the high-pressure chamber before each filling, and at the same time, it can also avoid the situation where air enters due to the excessively low pressure of the gas source cylinder 1.

[0036] In one embodiment, the high-pressure cavity is connected to the filled gas cylinder 2 through a fourth pipeline 44, and a first pressure detection device 61 and a second one-way valve 62 are provided on the fourth pipeline 44. The first pressure detection device 61 is used to detect the real-time pressure of the filled gas cylinder 2 during the gas filling process. A second pressure detection device 63 is provided on the liquid supply pipeline 45, and the second pressure detection device 63 is used to detect the real-time total pressure of the low-pressure cavity during the gas filling process.

[0037] When the pressure needs to be increased, liquid enters the low-pressure chamber of the pressure multiplier, the piston moves upward, and after the gas from the gas source cylinder in the high-pressure chamber is pressurized, the gas pressurized by the pressure multiplier is transported to the filled gas cylinder 2 through the four pipes 44, and the liquid in the middle chamber flows back to the liquid storage tank through the valve group; when the high-pressure end piston of the pressure multiplier moves to the top and needs to move downward, the liquid from the valve group in the middle chamber causes the piston to move downward, the piston needs to move downward, the high-pressure chamber sucks in the component gas from the gas source cylinder, and the liquid in the low-pressure chamber returns to the liquid storage tank through the valve group and the return liquid pipeline.

[0038] In one embodiment, a vacuum pump 64 is also included, which is connected to the fourth pipeline 44 and is used to evacuate the third pipeline 43, the fourth pipeline 44, the filled gas cylinder 2 and the high-pressure chamber before the first gas filling, so as to avoid the mixing of impurity gases during the gas filling process.

[0039] It should be noted that when there is a ratio requirement for the mixed gas cylinder, after the vacuuming process is completed, the gas from the gas cylinder with one component gas source is first used to fill the filled gas cylinder. After filling to the corresponding pressure required by the component, the gas of another component is used to fill the filled gas cylinder. If the volume of the gas cylinder is V, the maximum working pressure of the gas cylinder is P, and the amount of gas that can be filled in the gas cylinder under the pressure of P is n = PV / (RT). If the mixed gas is two permanent gases, and their contents are n1 and n2 respectively (the sum of n1 / n and n2 / n does not exceed 1), under the condition that the volume of the gas cylinder is fixed, n i Filling pressure Pi = n i R·T / V,P i ≤P, if the i component is 1, then P1=n1·R·T / V, the pressure when filling the second component after filling one component is P2=(n1+n2)·R·T / V=P1+n2·R·T / V, this value is also the pressure control indication of the pressure gauge in front of the gas cylinder being filled.

[0040] In one embodiment, the outlet of the vacuum pump 64, the outlet of the gas source cylinder 1 and the inlet of the filled gas cylinder 2 are all provided with valves 65, and the liquid return line 46 is provided with a heat exchanger 66 and an air filter 67. Considering that the liquid will generate heat during the pressurization process, the heat exchanger 66 is provided to recover the heat generated by the liquid and cool the liquid, and the air filter 67 can be used to remove the air in the liquid.

[0041] In one embodiment, the working pressure of the second one-way valve 62 is 10 to 100 times the working pressure of the first one-way valve 52. For example, the working pressure of the second one-way valve 62 may be 15 MPa, and the working pressure of the first one-way valve 52 may be 0.5 MPa.

[0042] In one embodiment, gas filling is accomplished by controlling the real-time total pressure of the low-pressure chamber to satisfy the following target formula:

[0043] P l ≥R g ·P g ·A2÷A1

[0044] Where P l is the real-time total pressure of the low-pressure chamber, R g is the preset gas pressure increase ratio, which is the ratio of the fixed volume to the volume of the component gas after being compressed in the high-pressure chamber, P g is the preset pressure, A2 is the area of ​​the high-pressure end piston, and A1 is the area of ​​the low-pressure end piston.

[0045] In order to increase the pressure of the component gases in the filled gas cylinder, the pressure multiplier used has two pistons. For the pressure multiplier with the pressure increasing function, the diameter or area of ​​the upper piston is smaller than the diameter or area of ​​the lower piston (such as Figure 1 As shown in the figure, due to the balance of forces at both ends of the piston, the liquid P l1 A1=P l2 A2, P l1 / P l2 =A2 / A1, the area ratio of the two determines the hydraulic pressure ratio R l , can realize the pressurization of liquid. However, for a pressure multiplier with gas at one end, if the high pressure end is the gas end, if the volume of the gas suction end is nV ’ , the volume after compression is V ’ After isothermal adiabatic gas compression, the gas pressure is n times the initial pressure, that is, the gas pressure increase ratio is R g , where the end volume can be close to zero void, the pressure of the high-pressure cylinder can reach very high pressure, and the pressure of the component gas from the gas source cylinder P g1 (i.e. P g ) enters the high pressure end through the one-way valve and is compressed to a pressure of P g2 (i.e. R g ·P g ), in P l1 A1≥P g2 A2 (i.e. P l ≥R g ·P g A2÷A1), the gas is discharged from the high-pressure end at the set pressure of the outlet check valve and transported to the pressurized gas cylinder.

[0046] For example, several 40-liter gas source cylinders with an internal pressure of about 5 MPa are used to inflate a 40-liter gas cylinder with a maximum working pressure of 15 MPa. The piston diameter of the low-pressure end of the pressure multiplier used is 200 mm, and the piston diameter of the high-pressure end is 100 mm. The maximum working pressure that the pump group and valve group can provide is 15 MPa, and the hydraulic driving force is 1.885x10 3 N, the component gas at the high-pressure end enters the pressure multiplier through the pressure reducing device. The gas pressure at the high-pressure end is 0.5MPa. The end of the high-pressure end piston is in a high-pressure cavity with a length of 300mm, so that the volume of the high-pressure cavity is the largest side. The volume of the high-pressure end is 2.355 liters. When the end of the high-pressure end piston moves to a distance of 3mm from the end of the cylinder body, the corresponding volume is 0.02355 liters. Under isothermal adiabatic compression, when the second one-way valve 62 is not opened, the corresponding pressure is 50MPa. This pressure is fully suitable for filling the gas cylinder gas.

[0047] After the filled gas cylinder and related pipelines are evacuated with a vacuum pump, the corresponding gas is pressurized and filled into the filled gas cylinder using a pressure multiplier connected to a different gas source cylinder. After each action of the pressure multiplier, the first pressure detection device 61 at the front end of the filled gas cylinder determines whether the pressure multiplier continues to work. If the pressure is lower than the set pressure, the pressure multiplier continues to work until the pressure detected by the first pressure detection device 61 at the front end of the filled gas cylinder reaches the set pressure.

[0048] In addition, an embodiment of the present invention further provides a method for filling a mixed gas. Based on the mixed gas filling system mentioned in the above embodiment, the method includes:

[0049] Before gas filling, the component gases in the gas source cylinder 1 are decompressed to a preset pressure by the decompression device 51 and then filled into the high-pressure cavity. At this time, the volume of the high-pressure cavity is a fixed volume;

[0050] When gas filling is performed, the real-time total pressure of the low-pressure cavity is controlled to satisfy the target formula so that the component gas in the high-pressure cavity is filled into the gas cylinder 2 to be filled.

[0051] It can be understood that the mixed gas filling method provided in this embodiment and the mixed gas filling system provided in the above-mentioned embodiment are based on the same inventive concept, and therefore both have the same beneficial effects, which will not be described in detail herein.

[0052] It should be noted that, in this article, relational terms such as first and second are only used 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 "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mixed gas filling system, characterized in that: It comprises at least two gas source cylinders, a gas cylinder to be filled and at least two sets of pressure multiplying devices, each of the gas source cylinders is connected to the gas cylinder to be filled via a set of the pressure multiplying devices, the pressure multiplying devices are used to hydraulically pressurize a fixed volume of component gas from the gas source cylinder by a preset multiple, and fill the pressurized high-pressure gas into the gas cylinder to be filled.

2. The mixed gas filling system according to claim 1, characterized in that: The pressure multiplier device includes a pressure multiplier and a liquid storage tank, the pressure multiplier is connected to the gas source cylinder and the liquid storage tank respectively, the liquid storage tank is used to store liquid, the high-pressure end of the pressure multiplier is used to accommodate a fixed volume of component gas from the gas source cylinder, and the low-pressure end is used to accommodate liquid from the liquid storage tank, and the pressure multiplier is used to pressurize the component gas at the high-pressure end by a preset multiple using the liquid at the low-pressure end.

3. The mixed gas filling system according to claim 2, characterized in that: The pressure multiplier device also includes a valve group and a pump group. The pressure multiplier is provided with a high-pressure end piston, a piston rod and a low-pressure end piston connected in sequence. The diameter of the high-pressure end piston is smaller than the diameter of the low-pressure end piston. An intermediate cavity is formed between the high-pressure end piston and the low-pressure end piston. The side of the high-pressure end piston away from the intermediate cavity forms a high-pressure cavity for accommodating component gases, and the side of the low-pressure end piston away from the intermediate cavity forms a low-pressure cavity. The intermediate cavity is connected to the valve group through a first pipeline, and the low-pressure cavity is connected to the valve group through a second pipeline. The valve group is connected to the liquid storage tank through a liquid supply pipeline and a liquid return pipeline respectively. The pump group is arranged on the liquid supply pipeline, and the valve group is used to control the flow direction of the liquid in the first pipeline and the second pipeline.

4. The mixed gas filling system according to claim 3, characterized in that: The gas source cylinder is connected to the high-pressure chamber through a third pipeline, and a pressure reducing device and a first one-way valve are provided on the third pipeline. The pressure reducing device is used to reduce the pressure of the gas source cylinder to a preset pressure so that a fixed volume of component gas is stored in the high-pressure chamber before filling.

5. The mixed gas filling system according to claim 4, characterized in that: The high-pressure chamber is connected to the filled gas cylinder through a fourth pipeline, and a first pressure detection device and a second one-way valve are provided on the fourth pipeline. The first pressure detection device is used to detect the real-time pressure of the filled gas cylinder during the gas filling process. The liquid supply pipeline is provided with a second pressure detection device, and the second pressure detection device is used to detect the real-time total pressure of the low-pressure chamber during the gas filling process.

6. The mixed gas filling system according to claim 5, characterized in that: It also includes a vacuum pump, which is connected to the fourth pipeline and is used to evacuate the third pipeline, the fourth pipeline, the filled gas cylinder and the high-pressure chamber before the first gas filling.

7. The mixed gas filling system according to claim 6, characterized in that: The outlet of the vacuum pump, the outlet of the gas source cylinder and the inlet of the filled gas cylinder are all provided with valves, and the liquid return pipeline is provided with a heat exchanger and an air filter.

8. The mixed gas filling system according to claim 5, characterized in that: The working pressure of the second one-way valve is 10 to 100 times the working pressure of the first one-way valve.

9. The mixed gas filling system according to any one of claims 5 to 8, characterized in that: Gas filling is accomplished by controlling the real-time total pressure of the low-pressure chamber to satisfy the following target formula: P l ≥R g ·P g ·A2÷A1 Where P l is the real-time total pressure of the low-pressure chamber, R g is a preset gas pressure increase ratio, which is the ratio of the fixed volume to the volume of the component gas after being compressed in the high-pressure chamber, P g is the preset pressure, A2 is the area of ​​the high-pressure end piston, and A1 is the area of ​​the low-pressure end piston.

10. A method for filling a mixed gas, characterized in that: Based on the mixed gas filling system according to claim 9, the method comprises: Before gas filling, the component gas of the gas source cylinder is decompressed to the preset pressure by the decompression device and then filled into the high-pressure cavity. At this time, the volume of the high-pressure cavity is the fixed volume; When gas filling is performed, the real-time total pressure of the low-pressure chamber is controlled to satisfy the target formula, so that the component gas in the high-pressure chamber is filled into the filled gas cylinder.

Images