A liquid delivery device and a liquid delivery method

Abstract

This application relates to a liquid delivery device and a liquid delivery method. The liquid delivery device includes a liquid storage tank having a liquid storage cavity for storing the liquid to be delivered; a liquid discharge pipe extending into the liquid storage cavity; a gas storage member having a gas storage cavity; a gas pipe assembly to which the gas storage member and the liquid storage tank are both connected; and a power member connected to the gas storage member. The power member has a first motion state and a second motion state. In the first motion state, the power member moves away from the gas pipe assembly to allow external gas to flow into the gas storage cavity through the gas pipe assembly; in the second motion state, the power member moves towards the gas pipe assembly to allow the gas in the gas storage cavity to flow into the liquid storage tank through the gas pipe assembly, thereby driving the liquid in the liquid storage tank to be discharged through the liquid discharge pipe. This liquid delivery device has a relatively simple structure, low maintenance difficulty, small delivery resistance, and high delivery flow rate.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical machinery, and particularly to a liquid conveying device and a liquid conveying method. Background Art

[0002] In many fields, there is a need to convey liquids. For example, in the field of nuclear fuel reprocessing, it is necessary to convey highly radioactive liquid waste. During the conveying process, various pumps are usually set up to achieve the conveying of the liquid waste through the suction of the pumps. However, this makes the structure of such conveying devices relatively complex and difficult to maintain. Moreover, some pumps will cause high-energy-consuming flow patterns such as jets and vortices during the liquid flow process, resulting in a large liquid conveying resistance and a low conveying flow rate. Summary of the Invention

[0003] Based on this, the present invention provides a liquid conveying device, which has a relatively simple structure, low maintenance difficulty, small conveying resistance, and high conveying flow rate.

[0004] The liquid conveying device includes:

[0005] A liquid storage tank having a liquid storage cavity for storing the liquid to be conveyed;

[0006] A liquid discharge pipe extending into the liquid storage cavity;

[0007] An air storage member having an air storage cavity;

[0008] An air pipe assembly to which the air storage member and the liquid storage tank are both connected;

[0009] A power member connected to the air storage member. The power member has a first motion state and a second motion state. In the first motion state, the power member moves away from the air pipe assembly to enable external air to flow into the air storage cavity through the air pipe assembly; in the second motion state, the power member moves towards the air pipe assembly to enable the gas in the air storage cavity to flow into the liquid storage tank through the air pipe assembly, thereby driving the liquid in the liquid storage tank to be discharged through the liquid discharge pipe.

[0010] In one embodiment, the air pipe assembly includes a first air pipe, a second air pipe, and a third air pipe. The first air pipe, the second air pipe, and the third air pipe form a tee. One end of the first air pipe communicates with the air storage cavity. The outlet end of the second air pipe and the inlet end of the third air pipe are both connected to the other end of the first air pipe. The inlet end of the second air pipe is used to communicate with the external environment, and the outlet end of the third air pipe communicates with the liquid storage cavity;

[0011] In the first motion state, external gas can flow through the second trachea and the first trachea in sequence and then flow into the gas storage cavity;

[0012] In the second motion state, the gas in the gas storage cavity can flow through the first trachea and the third trachea in sequence and then flow into the liquid storage cavity.

[0013] In one embodiment, an inlet valve is provided on the second trachea, and an outlet valve is provided on the third trachea. Both the inlet valve and the outlet valve are electric valves or hydraulic valves;

[0014] In the first motion state, the inlet valve is open and the outlet valve is closed; in the second motion state, the inlet valve is closed and the outlet valve is open.

[0015] In one embodiment, a pressure sensor is provided in the region of the third trachea between the outlet valve and the liquid storage tank. The pressure sensor is used to detect the air pressure in the liquid storage cavity.

[0016] In one embodiment, a diffused silicon sensor for detecting the pressure of the gas storage cavity and a T-type thermocouple for detecting the temperature of the gas storage cavity are provided on the gas storage member.

[0017] In one embodiment, the gas storage member is a cylinder, and the power member is connected to the piston of the cylinder. In the first motion state, the power member moves vertically downward; in the second motion state, the power member moves vertically upward, and a grease layer is provided on the top surface of the piston.

[0018] In one embodiment, the liquid delivery device further includes a temperature control member, and the temperature control member is wrapped around the outside of the gas storage member. The temperature control member is used to keep the gas storage cavity at a constant temperature.

[0019] In one embodiment, the temperature control member includes a water bath, and heat sinks are provided outside the water bath.

[0020] In one embodiment, the liquid delivery device further includes a spare pipe, and the spare pipe is connected to the liquid storage tank. The spare pipe is used to discharge the gas in the liquid storage cavity or add the liquid to be delivered into the liquid storage cavity.

[0021] The above liquid delivery device sucks external gas into the gas storage cavity or discharges the gas in the gas storage cavity into the liquid storage tank by moving the power member relative to the gas storage member, so as to discharge the liquid stored in the liquid storage tank through the liquid discharge pipe by means of pneumatic drive of gas replacing liquid, so as to realize the directional delivery of the liquid. This delivery method does not require a pump to provide suction force, so the structure is simpler and the maintenance difficulty of the device can be reduced. At the same time, since the structure with a pump will cause high-energy flow patterns such as jet flow and eddy current in the liquid flow process, and the delivery resistance is large, the liquid delivery device of the present application does not require a pump to provide suction force, and high-energy flow patterns such as jet flow and eddy current are not likely to exist in the liquid flow process, which can reduce the delivery resistance to a certain extent and increase the delivery flow rate.

[0022] The present invention also provides a liquid delivery method, which uses the above liquid delivery device and includes the following steps:

[0023] S100 Switch the area of the air pipe assembly for connecting the gas storage member and the liquid storage tank to the disconnected state, and switch the area of the air pipe assembly for connecting the gas storage member and the external environment to the connected state;

[0024] S200 Pull the power member to suck external gas into the gas storage cavity;

[0025] S300 Switch the area of the air pipe assembly for connecting the gas storage member and the external environment to the disconnected state, and push the power member to compress the gas in the gas storage cavity;

[0026] S400 When the air pressure in the gas storage cavity is equal to the air pressure in the liquid storage cavity, switch the area of the air pipe assembly for connecting the gas storage member and the liquid storage tank to the connected state, and continue to push the power member to press the gas in the gas storage cavity into the liquid storage cavity until the power member reaches the end of the stroke;

[0027] S500 Repeat S100 to S400.

[0028] In the above liquid delivery method, during the liquid delivery process, the delivery resistance is small and the delivery flow rate is high. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of a liquid delivery device in an embodiment of the present application;

[0030] Figure 2 It is a flow distribution diagram measured at different times when using the liquid delivery device of the present application to deliver liquid.

[0031] Reference Numerals:

[0032] Gas storage member 100, piston 110, gas storage cavity 120;

[0033] Power component 200;

[0034] Liquid storage tank 300, liquid storage cavity 310;

[0035] Liquid discharge pipe 400;

[0036] First air pipe 510, second air pipe 520, third air pipe 530;

[0037] Standby pipe 600;

[0038] Inlet valve 710, outlet valve 720, liquid discharge valve 730, standby valve 740;

[0039] First pressure sensor 810, first temperature sensor 820, second pressure sensor 830, second temperature sensor 840. Detailed implementation manners

[0040] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention in conjunction with the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0042] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0043] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present invention, unless otherwise clearly defined or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0045] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0046] Figure 1 It is a schematic structural diagram of a liquid delivery device in an embodiment of the present application.

[0047] Refer to Figure 1, a liquid delivery device provided by an embodiment of the present invention includes a gas storage member 100, a power member 200, a liquid storage tank 300, a liquid discharge pipe 400 and a gas pipe assembly. The gas storage member 100 has a gas storage cavity 120 capable of storing gas. The liquid storage tank 300 has a liquid storage cavity 310 for storing the liquid to be delivered. The liquid discharge pipe 400 extends into the liquid stored in the liquid storage cavity 310. Both the gas storage member 100 and the liquid storage tank 300 are connected to the gas pipe assembly, and the power member 200 is connected to the gas storage member 100. The power member 200 has a first motion state and a second motion state. In the first motion state, the power member 200 moves away from the gas pipe assembly to allow external gas to flow into the gas storage cavity 120 through the gas pipe assembly. In the second motion state, the power member 200 moves towards the gas pipe assembly to allow the gas in the gas storage cavity 120 to flow into the liquid storage tank 300 through the gas pipe assembly, thereby driving the liquid in the liquid storage tank 300 to be discharged through the liquid discharge pipe 400.

[0048] In the above liquid delivery device, the power member 200 moves relative to the gas storage member 100 to suck external gas into the gas storage cavity 120 or discharge the gas in the gas storage cavity 120 into the liquid storage tank 300. Thus, the liquid stored in the liquid storage tank 300 is discharged through the liquid discharge pipe 400 by means of pneumatic drive of gas replacing liquid, so as to achieve directional delivery of the liquid. This delivery method does not require a pump to provide suction force, so the structure is simpler and the maintenance difficulty of the device can be reduced. At the same time, since the structure with a pump will cause high-energy flow patterns such as jet flow and eddy current in the liquid flow process, and the conveying resistance is large, the liquid delivery device of the present application does not require a pump to provide suction force, and high-energy flow patterns such as jet flow and eddy current are not likely to exist in the liquid flow process, which can reduce the conveying resistance to a certain extent and increase the conveying flow rate.

[0049] Specifically, in some embodiments, the gas pipe assembly includes a first gas pipe 510, a second gas pipe 520 and a third gas pipe 530. The first gas pipe 510, the second gas pipe 520 and the third gas pipe 530 form a tee. One end of the first gas pipe 510 communicates with the gas storage cavity 120. The outlet end of the second gas pipe 520 and the inlet end of the third gas pipe 530 are both connected to the other end of the first gas pipe 510. The inlet end of the second gas pipe 520 is used to communicate with the external environment, and the outlet end of the third gas pipe 530 communicates with the liquid storage cavity 310. In the first motion state, external gas can flow into the gas storage cavity 120 after flowing through the second gas pipe 520 and the first gas pipe 510 in sequence. In the second motion state, the gas in the gas storage cavity 120 can flow into the liquid storage cavity 310 after flowing through the first gas pipe 510 and the third gas pipe 530 in sequence.

[0050] Specifically, from the perspective shown in the attached drawings, the left end of the second air pipe 520 is its inlet end, and the right end is its outlet end. The left end of the third air pipe 530 is its inlet end, and the right end is its outlet end. The bottom end of the first air pipe 510 communicates with the air storage cavity 120. The right end of the second air pipe 520 and the left end of the third air pipe 530 are both connected to the top end of the first air pipe 510. The left end of the second air pipe 520 is used to communicate with the external environment, and the right end of the third air pipe 530 communicates with the liquid storage cavity 310. In the first motion state, the second air pipe 520 is in a connected state, and the third air pipe 530 is in a disconnected state. The external gas can be pumped into the air storage cavity 120 through the second air pipe 520 and the first air pipe 510 by pulling the power member 200. In the second motion state, the second air pipe 520 is in a disconnected state, and the third air pipe 530 is in a connected state. The gas in the air storage cavity 120 can be pressed into the liquid storage cavity 310 through the first air pipe 510 and the third air pipe 530 by pushing the power member 200, so as to discharge the liquid stored in the liquid storage cavity 310 through the drain pipe 400 to realize the transportation of the liquid.

[0051] Further, in some embodiments, an inlet valve 710 is provided on the second air pipe 520, and an outlet valve 720 is provided on the third air pipe 530. Both the inlet valve 710 and the outlet valve 720 are electric valves or hydraulic valves. In the first motion state, the inlet valve 710 is opened and the outlet valve 720 is closed; in the second motion state, the inlet valve 710 is closed and the outlet valve 720 is opened.

[0052] Specifically, in the first motion state, the inlet valve 710 is opened and the outlet valve 720 is closed, so that the second air pipe 520 is in a connected state, and the third air pipe 530 is in a disconnected state, thereby completing the intake of the air storage cavity 120; in the second motion state, the inlet valve 710 is closed and the outlet valve 720 is opened, so that the second air pipe 520 is in a disconnected state, and the third air pipe 530 is in a connected state, thereby completing the exhaust of the air storage cavity 120. Both the inlet valve 710 and the outlet valve 720 are electric valves or hydraulic valves that can be remotely controlled. Such valves have a fast response speed, can realize opening and closing in a relatively timely manner, improve the accuracy of the control process, and make the liquid transportation process more stable.

[0053] In some embodiments, a first pressure sensor 810 for detecting the pressure of the air storage cavity 120 and a first temperature sensor 820 for detecting the temperature of the air storage cavity 120 are provided on the air storage member 100.

[0054] Preferably, in some embodiments, the first pressure sensor 810 is a diffused silicon sensor, and the first temperature sensor 820 is a T-type thermocouple. Both the diffused silicon sensor and the T-type thermocouple measure relatively quickly, can quickly measure the pressure and temperature of the gas in the air storage cavity 120, and thus timely adjust the intake and exhaust process of the gas, making the liquid transportation process more stable.

[0055] Similarly, a second temperature sensor 840 for detecting the temperature of the liquid storage cavity 310 is also provided on the liquid storage tank 300. Preferably, the second temperature sensor 840 is a sheathed T-type thermocouple, which is radiation-resistant, corrosion-resistant, has rapid measurement, and high accuracy.

[0056] In some embodiments, a second pressure sensor 830 is provided in the region of the third air pipe 530 between the outlet valve 720 and the liquid storage tank 300. The second pressure sensor 830 is used to detect the air pressure in the liquid storage cavity 310. Specifically, the liquid delivery device can be used in the field of nuclear fuel reprocessing, and the liquid to be delivered stored in the liquid storage tank 300 is a highly radioactive feed liquid. By arranging the second pressure sensor 830 on the third air pipe 530, compared with directly arranging it at the liquid storage tank 300 with higher radioactivity, it is beneficial for subsequent maintenance and improves the safety of maintenance. Preferably, the second pressure sensor 830 is a diffused silicon sensor.

[0057] In some embodiments, the gas storage member 100 is a cylinder, the power member 200 is connected to the piston 110 of the cylinder. In the first motion state, the power member 200 moves vertically downward; in the second motion state, the power member 200 moves vertically upward, and a grease layer is provided on the top surface of the piston 110.

[0058] Specifically, the power member is a servo motor, a stepper motor, an electric push rod or a hydraulic push rod, which has advantages such as fast response speed and small reciprocating positioning error, can improve the accuracy of the control process, and make the liquid delivery process more stable.

[0059] The power output end of the power member 200 is fixedly connected to the piston 110 of the cylinder. The axial direction of the cylinder is the vertical direction. When the power member 200 pulls the piston 110 downward, the gas can be sucked in; when the power member 200 pushes the piston 110 upward, the gas can be discharged. The vertical placement of the cylinder can make the sliding seal of the cylinder not affected by gravity, the sliding friction pair wears evenly, and it is also beneficial to the uniform distribution of the grease. The surplus grease of the piston 110 in the cylinder is supported on the upper surface of the piston 110 and will not fall off due to the influence of gravity. The piston 110 can always be lubricated with grease, and the movement process is smoother and it is not easy to get stuck.

[0060] In some embodiments, the liquid delivery device further includes a thermostatic member, which is wrapped around the outside of the gas storage member 100. The thermostatic member is used to keep the gas storage cavity 120 at a constant temperature. By setting the thermostatic member, the gas temperature in the gas storage cavity 120 can be kept as consistent as possible with that in the liquid storage cavity 310, reducing the heat exchange process after the gas in the cylinder is pressed into the liquid storage tank 300, which is beneficial to the stable delivery of the liquid. Similarly, a thermostatic member can also be provided outside the air pipe assembly to reduce heat dissipation.

[0061] Further, in some embodiments, the constant temperature component includes a water bath, and heat sinks are provided outside the water bath. Specifically, if the external temperature is relatively low, it may cause the temperature in the gas storage cavity 120 to dissipate too quickly. The gas storage member 100 can be heated by the water bath to keep the temperature as constant as possible. At the same time, if the external temperature is relatively high, it may cause the temperature in the gas storage cavity 120 to be too high. The heat dissipation area can be increased through the heat sinks, thereby accelerating heat dissipation to keep the temperature as constant as possible.

[0062] In some embodiments, the liquid delivery device further includes a spare pipe 600. The spare pipe 600 is connected to the liquid storage tank 300 and is used to discharge the gas in the liquid storage cavity 310 or add the liquid to be delivered into the liquid storage cavity 310. Specifically, a spare valve 740 is provided on the spare pipe 600. If the second pressure sensor 830 detects that the air pressure in the liquid storage cavity 310 is too high and has exceeded the safety value, the spare valve 740 can be opened to discharge part of the gas through the spare pipe 600 to avoid excessive pressure. In addition, the liquid to be delivered can also be added to the liquid storage cavity 310 through the spare pipe 600.

[0063] A drain valve 730 is provided on the drain pipe 400. When it is necessary to stop the liquid delivery, the drain valve 730 can be closed.

[0064] In some embodiments, the liquid delivery method is implemented using the liquid delivery device in any of the foregoing embodiments, and it includes the following steps:

[0065] S100 Switch the area of the air pipe assembly for connecting the gas storage member 100 and the liquid storage tank 300 to the disconnected state, and switch the area of the air pipe assembly for connecting the gas storage member 100 and the external environment to the connected state;

[0066] S200 Pull the power member 200 to draw external gas into the gas storage cavity 120;

[0067] S300 Switch the area of the air pipe assembly for connecting the gas storage member 100 and the external environment to the disconnected state, and push the power member 200 to compress the gas in the gas storage cavity 120;

[0068] S400 When the air pressure in the gas storage cavity 120 is equal to the air pressure in the liquid storage cavity 310, switch the area of the air pipe assembly for connecting the gas storage member 100 and the liquid storage tank 300 to the connected state, and continue to push the power member 200 to press the gas in the gas storage cavity 120 into the liquid storage cavity 310 until the power member 200 reaches the end of the stroke;

[0069] S500 Repeat S100 to S400.

[0070] Specifically, the area of the trachea assembly for connecting the gas storage member 100 and the liquid storage tank 300 is the third trachea 530, and the area of the trachea assembly for connecting the gas storage member 100 and the external environment is the second trachea 520. In S100, the inlet valve 710 is opened and the outlet valve 720 is closed so that the second trachea 520 is in a connected state and the third trachea 530 is in a disconnected state. In S200, the power member 200 is pulled downward to move the piston 110 downward, and the external gas is pumped into the gas storage cavity 120 successively through the second trachea 520 and the first trachea 510. In S300, the outlet valve 720 is closed and the third trachea 530 is also in a disconnected state. The power member 200 is pushed upward to move the piston 110 upward to compress the gas in the gas storage cavity 120. In S400, when the air pressure in the gas storage cavity 120 measured by the first pressure sensor 810 is equal to the air pressure in the liquid storage cavity 310 measured by the second pressure sensor 830, the outlet valve 720 is opened and the third trachea 530 is in a connected state. The power member 200 is continuously pushed upward, and the gas in the gas storage cavity 120 is pressed into the liquid storage cavity 310 successively through the first trachea 510 and the third trachea 530 until the power member 200 reaches the end of the stroke. Thus, one cycle is completed. By continuously repeating the above process, continuous transportation can be achieved.

[0071] In the above transportation method, after the first motion state ends, the gas in the gas storage cavity 120 is compressed first. When the air pressure in the gas storage cavity 120 is equal to the air pressure in the liquid storage cavity 310, the second motion state is entered. This can make the gas pressure as consistent as possible during each transportation, reduce the disturbance to the gas pressure in the liquid storage cavity 310, and thus improve the stability of the output flow rate.

[0072] In the above transportation process, the liquid is pressed out after air is pumped in. Air has much less viscosity than the liquid, so it can be pumped quickly. Moreover, the liquid storage tank 300 itself can also buffer the pressed-in gas, playing a role in buffering the output to a certain extent. Therefore, the smoothness of the transportation flow rate can be improved.

[0073] During the liquid transportation process, the liquid in the liquid storage tank 300 is pushed by air. The volume of the liquid discharged from the liquid storage tank 300 is equal to the volume that a certain amount of gas pressed into the liquid storage tank 300 should occupy at the pressure and temperature of the liquid storage tank 300. Dividing this volume by the sampling time gives the flow rate of the liquid. By adjusting the amount of gas pressed in according to the temperature and pressure in the liquid storage tank 300, the flow rate of the liquid can be controlled. The specific principle is as follows:

[0074] Let the first pressure sensor 810 measure the temperature in the air storage cavity 120 as T1, and the first temperature sensor 820 measure the air pressure in the air storage cavity 120 as P1; let the second temperature sensor 840 measure the temperature in the liquid storage cavity 310 as T2, and the second pressure sensor 830 measure the air pressure in the liquid storage cavity 310 as P2. Let the total volume of the air in the area between the air storage cavity 120, the first air pipe 510, the inlet valve 710 on the second air pipe 520 and the outlet valve 720 on the third air pipe 530 be V1, and the amount of substance be n1; let the volume of the air in the liquid storage tank 300 and the pipes connected to the liquid storage tank 300 be V2, and the amount of substance be n2. Denote the suction stage when the piston 110 moves downward as s, and the compression stage when the piston 110 moves upward as c.

[0075] At the end of the suction stage, the piston 110 is pulled to the lowermost end, the air storage cavity 120 is filled with air, the inlet valve 710 is closed, and the outlet valve 720 is closed. At this time, the total volume of the air in the area between the air storage cavity 120, the first air pipe 510, the inlet valve 710 on the second air pipe 520 and the outlet valve 720 on the third air pipe 530 is V 1s , the temperature is T 1si , the pressure is P 1si , the amount of substance is n 1si , i = 1, 2, 3… where i represents the number of compressions. Denote the position of the piston 110 at this time as 0, and the vertically upward direction as the recording direction of the displacement of the piston 110.

[0076] P 1si V 1s = n 1si RT 1si , i = 1, 2, 3… (1)

[0077] In the above formula (1), P 1si and T 1si are measured by the first pressure sensor 810 and the first temperature sensor 820. V 1s is determined by the device structure and is a constant that can be initially calibrated. Therefore, n 1si can be calculated by formula (1).

[0078] When the compression stage is completed, the volume of the air remaining at the outlet at the top of the cylinder is V 1r , the pressure is P 1ri , the temperature is T 1ri , the amount of substance is n 1ri .

[0079] P 1si V 1r = n 1ri RT 1si , i = 1, 2, 3… (2)

[0080] Similarly, in the above formula (2), V 1r and P 1ri are measured by the first pressure sensor 810 and the first temperature sensor 820. V 1r is determined by the device structure and is a constant that can be calculated. Therefore, n 1ri can be calculated by formula (2).

[0081] According to the above formulas (1) and (2), n 1si and n 1ri are obtained. After that, the amount of substance n 1ci of the gas discharged during each compression can be obtained by formula (3)

[0082] n 1ci = n 1si - n 1ri (3)

[0083] The above calculation is for the ideal state. However, in this device, since the first pressure sensor 810 and the first temperature sensor 820 are installed at the top of the cylinder, the cylinder cannot be completely emptied, and the remaining air volume after the cylinder is compressed cannot be ignored. V 1s and the volume swept by the piston 110 during the cylinder compression process are actually different. Therefore, V 1s and V 1r in the above formula need to be calibrated or calculated.

[0084] The calibration method for V 1s is to pull the piston 110 to the lowest end to fill it with air, then close the inlet valve 710, and push the piston 110 upward for compression in a constant-temperature and airtight manner. When the first pressure sensor 810 measures that the pressure in the air storage chamber 120 rises to twice the initial pressure, assuming the volume of the gas compressed by the stroke swept by the cylinder piston 110 is V c / 2 , then V 1s = 2V c / 2 .

[0085] The calculation method for V 1r is to assume that the volume swept by the cylinder piston 110 from zero point (i.e., the lowest end) upward to the end stroke is V c , V 1r = V 1s - V c .

[0086] V c / 2 and V c can be obtained from the piston 110 stroke and the cross-sectional area inside the cylinder.

[0087] Ideally, the amount of substance of the gas discharged during compression obtained according to formula (3) is the amount of substance of the gas injected into the liquid storage chamber 310. However, during the liquid transportation process, multiple suction operations are required. Therefore, each time gas is injected into the liquid storage chamber 310, there is residual gas in the liquid storage chamber 310 and the pipeline connected to the liquid storage chamber 310 that was injected previously. This results in a difference between the amount of substance of the gas discharged during compression obtained according to formula (3) and the amount of substance of the gas injected into the liquid storage chamber 310. Therefore, the following method is also required for calculation.

[0088] After the outlet valve 720 is opened during the compression stage, at a certain moment a, and at a moment b after Δt; the piston 110 moves uniformly upward during the process from a to b, with a moving speed of v. The amount of substance of the gas flowing from the cylinder into the liquid storage tank 300 during this process is Δn, and the average liquid flow rate is Q; the position of the piston 110 at moment b is d, and the liquid level in the liquid storage tank 300 is h; the inner cross-sectional area of the cylinder is S1, the inner cross-sectional area of the liquid storage tank 300 is S2, and when the liquid storage tank 300 and the pipeline connected to the liquid storage tank 300 are all filled with air, the volume of the air is V 2s ; when the liquid storage tank 300 has not undergone liquid transportation, the initial amount of substance of the air contained in the liquid storage tank 300 and the pipeline connected to the liquid storage tank 300 is n 2* , and the piston 110 has undergone m compression processes.

[0089] Between moment a and moment b, since the outlet valve 720 is opened, the air pressures in the air storage chamber 120 and the liquid storage chamber 310 are equal.

[0090] For the gas in the cylinder at moment a, list the ideal gas state equation, and there is

[0091] P 1a (V 1b + vS1Δt) = n 1a RT 1a (4)

[0092] For the gas in the liquid storage tank 300 at moment a, list the ideal gas state equation, and there is

[0093] P 1a (V 2b - QΔt) = n 2a RT 2a (5)

[0094] For the gas in the cylinder at moment b, list the ideal gas state equation, and there is

[0095] P 1b V 1b = (n 1a - Δn)RT 1b (6)

[0096] For the gas in the liquid storage tank 300 at time b, applying the ideal gas state equation, we have

[0097] P 1b V 2b =(n 2a +Δn)RT 2b (7)

[0098] According to the gas volume balance, the total volume V of the air in the gas storage cavity 120, the first air pipe 510, the region between the inlet valve 710 on the second air pipe 520 and the outlet valve 720 on the third air pipe 530 at time b 1b satisfies:

[0099] V 1b =V 1s -dS1 (8)

[0100] According to the gas volume balance, the total volume V of the air in the liquid storage tank 300 and the pipeline connected to the liquid storage tank 300 at time b 2b satisfies:

[0101] V 2b =V 2s -hS2 (9)

[0102] The V 1s in formula (8) can be obtained by the aforementioned calibration method.

[0103] According to the gas amount of substance balance, we have

[0104] n 1a +n 2a =n 2* +∑n 1ci , i = 1, 2, 3…, m (10)

[0105] The above 7 equations [formulas (4) to (10)] form a linear equation system, where P 1a 、P 1b 、T 1a 、T 2a 、T 1b 、T 2b can all be measured by the corresponding sensors, R is the ideal gas constant, d can be read from the historical record of the controller of the servo motor (i.e., the power component 200) or the control system of the stepping motor (i.e., the power component 200), V 2s 、n 2* can be obtained by initial calibration; Q is the target value and is also a known quantity; Δt is the sampling time, S1 and S2 are structure constants and are also known quantities; n 1ci is the process record value and is also a known quantity; so the equation system finally has V 1b 、V 2b, n 1a , n 2a , h, Δn, v, a total of 7 unknowns, can be linearly solved to obtain a unique solution.

[0106] V 2s , n 2* Can be initially calibrated in the following way:

[0107] V 2s The initial calibration method of is to fill the liquid storage tank 300 and the pipelines connected to the liquid storage tank 300 with water, and then introduce air to push out all the liquid until the liquid volume weighing device. After the outflow is completed, measure the volume of water, that is, V 2s .

[0108] n 2* The initial calibration method of is to seal the liquid storage tank 300 and press in air with an amount of substance of n 0* After the temperature in the tank returns to the temperature before the air is pressed in, record that the pressure in the liquid storage tank 300 after the air is pressed in is f times the pressure in the liquid storage tank 300 before the air is pressed in. Then the amount of substance n 2* = n 0* f / (f - 1).

[0109] The values obtained by solving the linear equations composed of the above 7 equations, the values with practical significance are v and h.

[0110] v is used for the control of the servo motor (i.e., the power component 200). Since there is no sudden change in the liquid delivery process, it is approximately considered that the running speed of the piston 110 in the next Δt process after time b is v calculated according to the process parameters from time a to time b. Let the servo motor rotate so that the power component 200 runs upward at a speed of v, then the liquid storage tank 300 will stably output liquid, and the output flow rate is Q.

[0111] The meaning of h is the liquid level of the liquid storage tank 300. When measuring and controlling the liquid output flow rate of the present invention, the liquid level of the liquid storage tank can be measured simultaneously. This is the advantage of the present invention.

[0112] The following provides a specific embodiment of the present invention:

[0113] The power component 200 selects the Zhengyuan Electromechanical 42 fixed-axis type lead screw stepper motor with a stroke of 12.7 - 80 mm and a thrust of 25 kg; the air storage component 100 selects the ZPCACSC standard cylinder with a cylinder diameter of 100 and a stroke of 100. A hole is drilled at the top of the cylinder, a T-type thermocouple is inserted, and a diffused silicon pressure sensor is connected, and good sealing is done; the outside of the cylinder is covered with an air heat sink; the inlet valve 710 and the outlet valve 720 select 24V micro solenoid valves; an air pipe assembly is connected to the top of the cylinder, and a diffused silicon pressure sensor is connected to the third air pipe 530; the liquid storage tank 300 is processed from stainless steel, sealed after inserting a T-type thermocouple, and the liquid storage tank 300 is filled with a high-level radioactive liquid simulated liquid; the drain valve 730 and the standby valve 740 are 24V micro solenoid valves. The power component 200 was controlled with a target flow rate of 100 mL / h to output the liquid by air displacement. The liquid flowed out into a beaker on an electronic balance, and the output flow rate was measured using the balance and a stopwatch. After measuring the density of the high-level radioactive liquid simulated liquid with a hydrometer, the mass weighed by the balance can be converted into the volume of the liquid. The experimental results are shown in Figure 2 , and it can be seen from Figure 2 that the output flow rate of the liquid by air displacement is stable, with an accuracy of about 1%, and it is a continuous quantitative output.

[0114] The liquid delivery device of the present invention can be used for the delivery of high-level radioactive liquid. This device is easy to maintain, has a small delivery resistance, a large delivery head, a stable flow delivery, a built-in flow rate measurement, and the flow rate is independent of the physical properties of the liquid. The device is easy to maintain because there are no mechanical moving parts in the high-level radioactive area; the delivery resistance is small because there are no high-energy-consuming flow patterns such as jet flow and eddy current during the fluid flow process; the delivery head is large because the delivery pressure of the present invention has no restrictions on the flow principle, and the delivery head only depends on the power, mechanical strength, and sealing ability of the device; the flow delivery is stable because there is no flow pattern transformation during the fluid flow process; the built-in flow rate measurement is because the volume of the replacement gas is calculated by detecting the temperature and pressure of the gas and combined with the sampling time to obtain the flow rate of the replaced liquid; the flow rate is independent of the physical properties of the liquid because the present invention delivers the liquid by the replacement method, which is a constant flow delivery. As long as the liquid does not dissolve air, its physical properties such as viscosity and density will not affect the flow rate.

[0115] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as the scope described in this specification.

[0116] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A liquid delivery device, characterized in that, Comprising: A liquid storage tank having a liquid storage cavity for storing the liquid to be transported; A liquid discharge pipe extending into the liquid storage cavity; A gas storage member having a gas storage cavity; A gas pipe assembly to which the gas storage member and the liquid storage tank are both connected; the gas pipe assembly includes a region for connecting the gas storage member to the external environment and a region for connecting the gas storage member to the liquid storage tank; A power member connected to the gas storage member, the power member having a first motion state and a second motion state. In the first motion state, the region of the gas pipe assembly for connecting the gas storage member to the liquid storage tank switches to a disconnected state, the region of the gas pipe assembly for connecting the gas storage member to the external environment switches to a connected state, and the power member moves away from the gas pipe assembly so that external gas flows into the gas storage cavity through the gas pipe assembly; In the second motion state, the region of the gas pipe assembly for connecting the gas storage member to the liquid storage tank switches to a connected state, the region of the gas pipe assembly for connecting the gas storage member to the external environment switches to a disconnected state, and the power member moves towards the gas pipe assembly so that the gas in the gas storage cavity flows into the liquid storage tank through the gas pipe assembly, thereby driving the liquid in the liquid storage tank to be discharged through the liquid discharge pipe; Before the first motion state ends and enters the second motion state, the region of the gas pipe assembly for connecting the gas storage member to the liquid storage tank switches to a disconnected state, the region of the gas pipe assembly for connecting the gas storage member to the external environment switches to a disconnected state, and the power member compresses the air pressure in the gas storage cavity so that the air pressure in the gas storage cavity is equal to the air pressure in the liquid storage cavity.

2. The liquid delivery device according to claim 1, wherein, The gas pipe assembly includes a first gas pipe, a second gas pipe, and a third gas pipe. The first gas pipe, the second gas pipe, and the third gas pipe form a tee. One end of the first gas pipe communicates with the gas storage cavity. The outlet end of the second gas pipe and the inlet end of the third gas pipe are both connected to the other end of the first gas pipe. The inlet end of the second gas pipe is used to communicate with the external environment, and the outlet end of the third gas pipe communicates with the liquid storage cavity; In the first motion state, external gas can flow into the gas storage cavity after flowing through the second gas pipe and the first gas pipe in sequence; In the second motion state, the gas in the gas storage cavity can flow into the liquid storage cavity after flowing through the first gas pipe and the third gas pipe in sequence.

3. The liquid delivery device according to claim 2, characterized in that, An inlet valve is provided on the second gas pipe, and an outlet valve is provided on the third gas pipe. Both the inlet valve and the outlet valve are electric valves or hydraulic valves; In the first motion state, the inlet valve is open and the outlet valve is closed; in the second motion state, the inlet valve is closed and the outlet valve is open.

4. The liquid delivery device according to claim 3, wherein A pressure sensor is provided in the region of the third gas pipe between the outlet valve and the liquid storage tank, and the pressure sensor is used to detect the air pressure in the liquid storage cavity.

5. The liquid delivery device according to claim 1, wherein A diffused silicon sensor for detecting the pressure of the gas storage cavity and a T-type thermocouple for detecting the temperature of the gas storage cavity are provided on the gas storage member.

6. The liquid delivery device according to claim 1, characterized in that, The gas storage member is a cylinder, the power member is connected to the piston of the cylinder, in the first motion state, the power member moves vertically downward; in the second motion state, the power member moves vertically upward, and a grease layer is provided on the top surface of the piston.

7. The liquid delivery device according to claim 1, characterized in that, The liquid delivery device further includes a temperature control member, the temperature control member is wrapped around the outside of the gas storage member, and the temperature control member is used to keep the gas storage cavity at a constant temperature.

8. The liquid delivery device according to claim 7, characterized in that, The temperature control member includes a water bath, and heat dissipation fins are provided outside the water bath.

9. The liquid delivery device according to claim 1, wherein, The liquid delivery device further includes a spare pipe, the spare pipe is connected to the liquid storage tank, and the spare pipe is used to discharge the gas in the liquid storage cavity or add the liquid to be delivered into the liquid storage cavity.

10. A liquid delivery method, characterized in that, Using the liquid delivery device according to any one of claims 1 to 9, includes the following steps: S100 Switch the area of the air pipe assembly for connecting the gas storage member and the liquid storage tank to a disconnected state, and switch the area of the air pipe assembly for connecting the gas storage member and the external environment to a connected state; S200 Pull the power member to draw external gas into the gas storage cavity; S300 Switch the area of the air pipe assembly for connecting the gas storage member and the external environment to a disconnected state, and push the power member to compress the gas in the gas storage cavity; S400 When the pressure in the gas storage cavity is equal to the pressure in the liquid storage cavity, switch the area of the air pipe assembly for connecting the gas storage member and the liquid storage tank to a connected state, and continue to push the power member to press the gas in the gas storage cavity into the liquid storage cavity until the power member reaches the end of the stroke; S500 Repeat S100 to S400.

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