A flow detection device

Abstract

This application provides a flow detection device. It includes a liquid-gas chamber and an inlet pipe and an outlet pipe respectively connected to the liquid-gas chamber. A liquid medicine is pre-filled into the liquid-gas chamber through the inlet pipe, so that part of the liquid-gas chamber is filled with liquid and the other part is filled with gas, as a pre-operating state. A gas pressure detector is connected to the gas-filled space of the liquid-gas chamber to obtain the gas pressure P. In the operating state, the liquid flows along the path of the inlet pipe → liquid-gas chamber → outlet pipe. The inlet flow rate Q of the inlet pipe is obtained at least based on the gas pressure P. in The liquid flow rate Q of the liquid outlet pipeline out The flow rate difference ΔQ; the inlet flow rate Q is adjusted based on this flow rate difference ΔQ. in Therefore, it is possible to precisely control the flow.

Description

Technical Field

[0001] This application relates to a flow detection device capable of precisely controlling flow rate. Background Technology

[0002] During surgery, it is often necessary to supply the affected area with saline solution or other medications. In existing technology, a discharge line equipped with a high-pressure pump is directly connected to a reservoir (e.g., a saline bag), and the high-pressure pump draws the medication from the reservoir. Simultaneously, a flow meter measures the flow rate of the medication in the discharge line.

[0003] On the other hand, the medical and health fields have very strict requirements for the safety of flow measurement and flow control, usually requiring non-contact measurement. Currently, the mainstream non-contact flow meter is the ultrasonic flow meter based on the Doppler principle, which is not only expensive, but also has lower measurement accuracy than rigid pipes (especially in cases of expansion and deformation). Moreover, because medical high-pressure pumps have low flow rates, they usually do not have a primary pump at the inlet. In some situations, such as at high altitudes with low air pressure and high flow demand, this can easily lead to insufficient inlet pressure and reduced flow rate.

[0004] Therefore, in existing technologies, how to accurately control the flow rate has become a technical challenge. Utility Model Content

[0005] The purpose of this application is to provide a flow detection device capable of accurately controlling flow rate. To achieve the above objective, one solution of this application is a flow control device / flow detection device, characterized in that: it includes a liquid-gas chamber and an inlet pipe and an outlet pipe respectively connected to the liquid-gas chamber; a liquid medicine is pre-filled into the liquid-gas chamber through the inlet pipe, such that part of the liquid-gas chamber is filled with the liquid medicine and another part is filled with gas, as a preparatory working state; wherein, the gas-filled space of the liquid-gas chamber is connected to a gas pressure detector for obtaining the gas pressure P; in the working state, the liquid medicine flows along the path of the inlet pipe → the liquid-gas chamber → the outlet pipe; the inlet flow rate Q of the inlet pipe is obtained at least based on the gas pressure P. in The liquid flow rate Q of the liquid outlet pipeline out The flow rate difference ΔQ; the inlet flow rate Q is adjusted based on this flow rate difference ΔQ. in And based on the adjusted inlet flow rate Q of the inlet pipeline. in The outlet flow rate Q of the outlet pipeline is calculated using the flow rate difference ΔQ obtained after adjustment. out .

[0006] In a preferred embodiment, a mapping relationship between the gas pressure P and the flow rate difference ΔQ is established in advance. During operation, the liquid inlet flow rate Q is adjusted based on this mapping relationship and the gas pressure P. in .

[0007] In a preferred embodiment, a gas temperature detector connected to the gas-filled space of the liquid-gas chamber is further provided to acquire the gas temperature T; a mapping relationship between the gas pressure P and the flow rate difference Q is pre-established for different gas temperatures T; in operation, based on the measured gas temperature T, the corresponding mapping relationship, and the gas pressure P, the liquid inlet flow rate Q is adjusted. in .

[0008] In a preferred embodiment, during operation, the cross-sectional area of ​​the gas-filled portion of the liquid-gas chamber along the liquid surface direction is smaller than the cross-sectional area of ​​the liquid-filled portion along the liquid surface direction.

[0009] In a preferred embodiment, at least based on a specified flow rate Q of the outlet line. mean , obtain the gas volume V0 filling the liquid-gas chamber in the set pre-operation state.

[0010] In a preferred embodiment, V0 = 1.6Q mean .

[0011] In a preferred embodiment, ΔQ = 1 / 8V0.

[0012] According to the aforementioned technical solution, the effect of accurately controlling the liquid flow rate can be achieved at a relatively low cost. Attached Figure Description

[0013] To more clearly illustrate this application, the accompanying drawings will be described and explained below. Obviously, the drawings described below only illustrate certain aspects of some exemplary embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0014] Figure 1 This is a schematic diagram of the overall structure of the flow detection device.

[0015] Figure 2 This is a schematic diagram of the liquid-gas chamber.

[0016] Attached image caption:

[0017] 1 liquid-gas chamber

[0018] 11. Fixed outer casing

[0019] 12 Liquid-Gas Chamber Shell

[0020] 2. Liquid inlet pipe

[0021] 21 Peristaltic Pump

[0022] 22 Peristaltic pump inlet hose

[0023] 23 Peristaltic pump outlet hose

[0024] 3. Liquid outlet pipeline

[0025] 31 High-pressure pump

[0026] 32 liquid outlet probe

[0027] 4 Gas pressure detector

[0028] 41 detection probes

[0029] 5 Gas Temperature Detector

[0030] 6 controllers

[0031] 7 Liquid Storage Tanks Detailed Implementation

[0032] Various exemplary embodiments of this application are described in detail below with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the application or its application or use. This application can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the application thorough and complete, and to fully express the scope of the application to those skilled in the art. It should be noted that, unless otherwise stated, the relative arrangement of components and steps, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0033] As used in this application, the words “including” or “comprising” or similar terms mean that the element preceding the word covers the element listed after the word, and do not exclude the possibility that it may also cover other elements.

[0034] All terms used in this application (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as being interpreted with idealized or highly formalized meanings, unless explicitly defined herein.

[0035] For components, specific model numbers and other parameters of components not described in detail in this section, the interrelationships between components and control circuits, these may be considered as techniques, methods and devices known to those skilled in the art, but where appropriate, such techniques, methods and devices should be considered part of the specification.

[0036] Overall Structure

[0037] The following is for reference Figure 1 and Figure 2 This application describes its overall structure. Figure 1 This is a schematic diagram of the overall structure of the flow detection device. Figure 2 This is a schematic diagram of the liquid-gas chamber 1.

[0038] The flow detection device of this application includes a liquid-gas chamber 1 and an inlet pipe 2 and an outlet pipe 3 respectively connected to the liquid-gas chamber 1. In this embodiment, the inlet pipe 2 includes a peristaltic pump 21, and a peristaltic pump inlet hose 22 and a peristaltic pump outlet hose 23 respectively connected to the inlet and outlet ends of the peristaltic pump 21. The outlet pipe 3 is also connected to the inlet end of a high-pressure pump 31. In this invention, the peristaltic pump 21 is equivalent to the inlet pumping device on the inlet pipe 2, and the high-pressure pump 31 is equivalent to the outlet pumping device on the outlet pipe 3. The inlet flow rate of the peristaltic pump 21 is indicated by a host computer, such as a computer.

[0039] In a preferred embodiment, the liquid-gas chamber 1 of this application is surrounded by a liquid-gas chamber housing 12, which is a consumable material, and is installed within a fixed housing 11. Exemplarily, the liquid-gas chamber housing 12 is made of rigid plastic, and has two openings in a soft rubber sheet for inserting the liquid outlet probe 32 and the detection probe 41, thus sealing the connection between these two probes and the liquid-gas chamber 1. The inlet end of the peristaltic pump 21 is connected to the liquid storage tank 7 via a peristaltic pump inlet hose 22, and the outlet end is connected to the liquid-gas chamber housing 12 via a peristaltic pump outlet hose 23.

[0040] Here, the inlet end of the peristaltic pump 21 is connected to the reservoir 7 via the peristaltic pump inlet hose 22, and a probe can be inserted into the reservoir 7. Furthermore, the outlet end of the peristaltic pump 21 is connected to the liquid-gas chamber housing 12 via the peristaltic pump outlet hose 23. This connection can be achieved by pre-manufacturing the liquid-gas chamber housing 12 and the outlet end of the peristaltic pump 21 together via the peristaltic pump outlet hose 23. Furthermore, this embodiment shows the peristaltic pump hoses at the inlet and outlet ends of the peristaltic pump 21 using the peristaltic pump inlet hose 22 and the peristaltic pump outlet hose 23, but the peristaltic pump inlet hose 22 and the peristaltic pump outlet hose 23 can also be the same hose passing through the peristaltic pump 21. Additionally, exemplarily, the drug solution described in this application is physiological saline, but it is not actually limited to this.

[0041] As a medical pump, the high-pressure pump 31 requires high precision in flow control. Existing technologies typically require non-contact measurement. Currently, the mainstream non-contact flow meter is the ultrasonic flow meter based on the Doppler principle, which is not only expensive but also has lower measurement accuracy than rigid pipes, especially when there is expansion or deformation. Moreover, because the high-pressure pump 31 has a small flow rate, it is usually not connected to a primary pump at the inlet. In some situations, such as at high altitudes with low air pressure and a large flow demand, insufficient inlet pressure and reduced flow can easily occur, meaning that the flow rate of the high-pressure pump 31 is prone to fluctuations and is difficult to control precisely.

[0042] Compared with the prior art, this application adds a liquid-gas chamber 1 to the flow path. For example, during preoperative preparation, the medication is pre-filled into the liquid-gas chamber 1 through the inlet pipe 2, so that part of the liquid-gas chamber 1 is filled with the medication and the other part is filled with gas, thus preparing it for operation. Specifically, see [link to relevant documentation]. Figure 2 As a preferred embodiment, the liquid-gas chamber 1 is placed horizontally as shown in the figure. The inlet pipe 2 and outlet pipe 3 are both connected to the same side of the liquid-gas chamber 1, while the detection probe 41 is connected to the opposite side of the liquid-gas chamber 1, opposite to the inlet pipe 2 and outlet pipe 3. The outlet probe 32 of the outlet pipe 3 is inserted into the liquid-gas chamber 1 to a predetermined depth. Furthermore, this embodiment is merely illustrative, and the liquid-gas chamber 1 is not limited to the approximately rectangular shape shown in the figure.

[0043] It is understood that the inlet pipe 2 and the outlet pipe 3 can be connected to different sides of the liquid-gas chamber 1. For example, the outlet pipe 3 can be connected to the lower side of the liquid-gas chamber 1 to facilitate water discharge, while the inlet pipe 2 can be connected to other sides of the liquid-gas chamber 1. Alternatively, the outlet pipe 3 can also be connected to other sides of the liquid-gas chamber 1, not limited to the lower side. These are just different embodiments, all of which are within the scope of protection of this application. In addition, the term "lower side" in this application refers to the lower side in the direction of gravity.

[0044] by Figure 2 A coordinate system is established with the opening of the liquid outlet probe 32 as the origin. The direction of the plumb line passing through this origin is the Y-axis, and the horizontal direction passing through this origin is the X-axis. The space within the liquid-gas chamber 1 is divided by the X-axis and Y-axis. Figure 2 Spaces A and B are shown. In... Figure 2 In the coordinate system shown, space A is equivalent to the space in the first quadrant plus the fourth quadrant of liquid-gas chamber 1, and space B is equivalent to the space in the third quadrant plus the fourth quadrant of liquid-gas chamber 1.

[0045] During operation, the liquid outlet probe 32 penetrates from the lower side of the liquid-gas chamber 1 in the direction of gravity. Therefore, the liquid needs to be filled to at least the area of ​​space B so that the liquid level covers the opening of the liquid outlet probe 32. However, since other areas of the liquid-gas chamber 1 are sealed, if the liquid is poured directly in the horizontal position shown in the figure, when the liquid level covers the opening of the liquid outlet probe 32 and reaches the X-axis, and the liquid fills space B, the pressure will increase due to the compression of the gas, making it difficult to continue pouring more liquid. Therefore, the liquid-gas chamber 1 is first rotated clockwise and laid down, for example, so that the liquid outlet probe 32 is turned upwards. The peristaltic pump 21 is then turned on to pump the liquid in until the liquid level covers the liquid outlet probe 32, that is, the liquid fills space A. At this time, the liquid is discharged from the liquid outlet pipe 3, and the air in the liquid outlet pipe 3 is also discharged. Then, the liquid-gas chamber 1 is rotated counterclockwise to straighten it to a horizontal position. If the volume of space A is greater than the volume of space B, then after the liquid-gas chamber 1 is uprighted, the liquid level will be a certain height above the liquid outlet pipe 3, thus completing the pre-venting work.

[0046] In this embodiment, the liquid-gas chamber 1 can also be rotated counterclockwise and laid down. In this case, space A is equivalent to Figure 2 The space A is the second quadrant plus the third quadrant of the liquid-gas chamber 1. Preferably, space A can be chosen from the larger of the first quadrant plus the fourth quadrant and the space between the second quadrant plus the third quadrant. This is because, since gas pressure and gas volume are inversely proportional at the same temperature, retaining less air in the liquid-gas chamber 1 makes the change in gas pressure relative to the change in gas volume more sensitive, and allows for more accurate measurement of changes in gas pressure.

[0047] Continue reading Figure 1 , Figure 2 The gas-filled space of the liquid-gas chamber 1 is connected to a gas pressure detector 4 to obtain the gas pressure P; more preferably, the gas-filled space of the liquid-gas chamber 1 is connected to a gas temperature detector 5 to obtain the gas temperature T. Preferably, the gas pressure detector 4 and the gas temperature detector 5 are respectively connected to a controller 6. The controller 6 can be a host computer such as a computer, or a slave computer such as a microcontroller. As mentioned above, preferably, the liquid outlet probe 32 is positioned on the lower side of the gravity direction in the working state of the liquid-gas chamber 1, and the gas pressure detector 4 and the gas temperature detector 5 are positioned on the upper side of the gravity direction in the working state of the liquid-gas chamber 1 to avoid contact with water.

[0048] In operation, the liquid flows through the following path: inlet pipe 2 → liquid-gas chamber 1 → outlet pipe 3; the inlet flow rate Q of inlet pipe 2 is obtained based on at least the gas pressure P. in The discharge flow rate Q of the discharge pipeline 3 out The flow rate difference ΔQ is calculated, and the inlet flow rate Q is adjusted based on this flow rate difference ΔQ. in .

[0049] Specifically, under operating conditions, when the inlet flow rate Q in Greater than the liquid flow rate Q out At this time, the amount of liquid in the liquid-gas chamber 1 increases, the gas is compressed, and the gas pressure P increases. At this time, it is necessary to reduce the deceleration of the peristaltic pump 21 to reduce the liquid inlet flow rate Q. in When the inlet flow rate Q in Less than the outflow rate Q out At this time, the liquid in the liquid-gas chamber 1 decreases, the gas expands, and the gas pressure P decreases. Therefore, it is necessary to increase the deceleration of the peristaltic pump 21 to increase the inlet flow rate Q. in The change in gas volume V, ΔV, is equal to the flow rate difference, ΔQ.

[0050] Therefore, as a preferred method, after completing the pre-venting process, the gas pressure and temperature at this point are recorded as the initial gas pressure P0 and initial gas temperature T0. Based on the initial gas pressure P0, initial gas temperature T0, and the real-time measured gas pressure P and gas temperature T, the liquid inlet flow rate Q is adjusted. in When the inlet flow rate Q in Greater than the liquid flow rate Q out When the flow rate is high, decrease the deceleration of peristaltic pump 21; conversely, increase the deceleration of peristaltic pump 21 to increase the inlet flow rate Q. in and liquid flow rate Q out Maintaining dynamic balance ensures stable flow rate of high-pressure pump 31. Generally, under operating conditions, the gas filling the liquid-gas chamber 1 satisfies PV / T = C, where P is the gas pressure, T is the gas temperature, V is the gas volume, and C is a constant. When the gas is compressed by the liquid, V decreases and P increases, and vice versa; the two are inversely proportional.

[0051] Therefore, more preferably, a mapping relationship between gas pressure P and flow rate difference ΔQ at different gas temperatures T is established in advance; under operating conditions, the liquid inlet flow rate Q is adjusted based on the measured gas temperature T, the corresponding mapping relationship, and the gas pressure P. in This makes the inlet flow rate Q in and liquid flow rate Q out Maintaining dynamic balance ensures stable flow rate of high-pressure pump 31.

[0052] Specifically, the real-time measured gas pressure P, gas temperature T, and gas volume V satisfy the following relationship with the initial gas pressure P0, initial gas temperature T0, and initial gas volume V0 recorded after the pre-exhaust work is completed: P0V0 / T0=PV / T. Therefore, V=P0T / PT0×V0, and the flow difference ΔQ=V-V0=(P0T / PT0-1)V0, which is the volume difference between V and V0.

[0053] Here, the "change in gas volume" as used in this invention refers to the difference between the real-time measured gas volume V and the initial gas volume V0, and the "change in gas pressure" refers to the difference between the real-time measured gas pressure P and the initial gas pressure P0.

[0054] In this invention, the peristaltic pump 21 can be adjusted to make V-V0 equal to 0, thus maintaining a constant liquid volume within the liquid-gas chamber 1. In this case, it is equivalent to adjusting the inlet flow rate Q. in Follow the liquid flow rate Q out Therefore, the pumping flow rate of the high-pressure pump 31 is always equivalent to that of the peristaltic pump 21. Since the pumping flow rate of the peristaltic pump 21 is indicated by a host computer, the pumping flow rate of the high-pressure pump 31 can be directly determined. In this way, the pumping flow rate of the high-pressure pump 31 can be easily obtained without the need for expensive ultrasonic flow meters as in existing technologies.

[0055] On the other hand, in this invention, V-V0 may not be zero. That is, as long as V-V0 can be kept within a specified range, the flow difference ΔQ can have a certain degree of linearity relative to the gas pressure P. In this case, it is equivalent to making the inlet flow rate Q... in Approximately equal to the outflow rate Q out Q in Do not deviate from Q out Too much. Based on the flow difference ΔQ = V - V0 = (P0T / PT0 - 1)V0, plus the pumping flow rate of the peristaltic pump 21 indicated by the host computer, the pumping flow rate of the high-pressure pump 31 can also be determined. Similarly, the pumping flow rate of the high-pressure pump 31 can be easily obtained without using an expensive ultrasonic flow meter as in existing technologies.

[0056] Furthermore, based on the relationship of flow difference ΔQ = V - V0 = (P0T / PT0 - 1)V0, the real-time flow difference ΔQ can be obtained by using the initial gas pressure P0 detected by gas pressure detector 4 and the real-time measured gas pressure P, and the initial gas temperature T0 detected by gas temperature detector 5 and the real-time measured gas temperature T. However, since the gas volume V is proportional to the gas pressure P and the gas temperature T, especially inversely proportional to the gas pressure P, when the gas pressure P is extremely high or extremely low, the change in gas volume V is equivalent to being insensitive or overly sensitive to the gas pressure P, making it difficult to measure accurately.

[0057] Therefore, the flow detection device of the present invention first determines the current flow difference ΔQ(Q in -Q out This is equivalent to checking whether the change in gas volume (V - V0) is within the specified range ΔQmin to ΔQmax. If the current flow difference ΔQ is not within the specified range ΔQmin to ΔQmax, first adjust the inlet flow rate Q.in When the inlet flow rate Q in Greater than the liquid flow rate Q out When the flow rate is high, decrease the deceleration of peristaltic pump 21; conversely, increase the deceleration of peristaltic pump 21 to increase the inlet flow rate Q. in and liquid flow rate Q out The flow difference ΔQ is brought within the specified range ΔQmin to ΔQmax, thus maintaining the linearity and accuracy of the flow difference ΔQ calculation. Next, the adjusted inlet flow rate Q of inlet line 2 is used. in The discharge flow rate Q of the discharge line 3 is calculated using the adjusted flow rate difference ΔQ. out .

[0058] In the aforementioned embodiment, by adjusting the peristaltic pump 21 to make V-V0 become 0, which corresponds to the inlet flow rate Q. in The extreme cases of adjustment.

[0059] For example, as a preferred approach, in practical applications, the required outlet flow rate Q of the high-pressure pump 31 is... out Typically known values ​​are taken, and the median is used as the specified flow rate Q of the outlet pipe 3. mean At least based on Q mean Set the initial volume V0 of the gas filling the liquid-gas chamber 1 in the pre-operation state.

[0060] Specifically, as a preferred approach, the magnitude of the flow difference ΔQ needs to be set based on the flow rate to be measured, i.e., the flow rate of the outlet line 3. Considering a rough percentage of the fluctuation range of the flow rate to be measured, the flow rate of the peristaltic pump 21 is controlled to be the design value of the flow rate to be measured plus or minus the design value of the flow difference ΔQ. In this way, the actual range of the flow difference ΔQ is easier to control and highly correlated with the flow rate to be measured. For example, if the design value of the flow rate to be measured is 40 ml / min ± 10%, which is 36-44 ml / min, and the flow rate of the peristaltic pump 21 is controlled to be 50 ml / min, then the flow difference ΔQ is 6-14 ml / min. As another example, the design value of the flow rate to be measured for another setting is 150 ml / min, with a fluctuation range of ± 10%, i.e., 135-165 ml / min. If the flow rate of peristaltic pump 21 is still controlled to be 10 ml / min higher than the design value of the flow rate to be measured, i.e., 160 ml / min, then the actual range of the flow rate difference ΔQ is -5 to 25 ml / min. It is possible that the flow rate difference ΔQ is very small, or even 0 or negative. A flow rate difference ΔQ of 0 indicates that the outflow flow rate Q out Equal to the inlet flow rate Q in This is the flow rate of peristaltic pump 21. At this point, there is no need to adjust the speed of peristaltic pump 21. A negative flow rate difference ΔQ indicates that the outflow flow rate Q is... out Greater than the inlet flow rate Q in At this point, it is necessary to increase the speed of the peristaltic pump 21.

[0061] For example, the design value of the flow difference ΔQ = 1 / 8 × V0 = 0.2 × Q mean At this point, according to Q mean The initial gas volume in liquid-gas chamber 1 is determined to be V0 = 1.6Q. mean The design value of the flow difference ΔQ is then set to 1 / 8 of the initial gas volume V0. This means that during control, a relatively ideal range of flow difference ΔQ is set based on the known initial value of V0. The actual value of the flow difference ΔQ fluctuates around this set value during operation. For example, at a certain gas temperature T, if we measure over 2 seconds, the gas pressure P in liquid-gas chamber 1 changes from 111 kPa to 148 kPa, corresponding to a change of (148-111) / 111 = 33% in gas pressure. The change in gas volume V is 2 × 1 / 8 = 25%. This is because, according to the formula PV / T = C, when the gas pressure P increases by 1 / 3, P becomes 4 / 3 of its original value. Therefore, according to the inverse relationship, the gas volume V should become 3 / 4 of its original value, meaning the gas volume V should decrease by 1 / 4. This range of change can be measured relatively accurately using the common accuracy and linearity of a commonly used measuring instrument.

[0062] As a preferred approach, in the working state, the cross-sectional area of ​​the gas-filled portion of the liquid-gas chamber 1 along the liquid surface direction is smaller than the cross-sectional area of ​​the liquid-filled portion along the liquid surface direction. Specifically, the vertical cross-section of the liquid-gas chamber 1 is not limited to the rectangle shown in the figure; it can be trapezoidal, conical, or other shapes, such that the horizontal cross-sectional area of ​​the upper gas-filled portion is smaller than the horizontal cross-sectional area of ​​the lower liquid-filled portion. Thus, under the same flow difference ΔQ, the change in liquid level rise and fall in the upper gas-filled portion is greater, and the change in gas pressure P is also greater. In other words, the gas pressure P responds more sensitively to the flow difference ΔQ, thereby further enhancing the accuracy of flow control.

[0063] In summary, the flow detection device of this application does not require direct measurement of the actual flow rate at the outlet pipe 3 and the high-pressure pump 31 during operation. It only needs to calculate the gas volume change within the liquid-gas chamber 1 based on the gas pressure change, thereby obtaining the flow difference between the inlet pipe 2 and the outlet pipe 3. Then, based on this flow difference and the flow rate of the inlet pipe 2, the flow rate of the outlet pipe 3 is measured. Here, the flow rate of the inlet pipe 2 is the flow rate of the peristaltic pump 21. Simultaneously, it ensures that the pressure at the inlet of the high-pressure pump 31 is unaffected by altitude, atmospheric pressure, etc.

[0064] Furthermore, this application uses the peristaltic pump 21, pressure sensor 4, gas temperature sensor 5, controller 6, and fixed housing 11 as reusable devices. The gas temperature sensor 5 can be integrated into the pressure sensor 4 or installed in the fixed housing 11. The liquid-gas chamber housing 12, peristaltic pump inlet hose 22, and liquid storage tank 7 are used as consumables, which reduces costs and facilitates disassembly and assembly while achieving flow control.

[0065] It should be understood that the specific embodiments described above are only used to explain this application, and the scope of protection of this application is not limited thereto. Any changes, substitutions, or combinations made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and concept of this application, should be covered within the scope of protection of this application.

Claims

1. A flow detection device, characterized in that: It includes a liquid-gas chamber and an inlet pipe and an outlet pipe respectively connected to the liquid-gas chamber; The liquid medicine is pre-filled into the liquid-gas chamber through the liquid inlet pipe, so that part of the liquid-gas chamber is filled with the liquid medicine and the other part is filled with gas, thus preparing it for operation. The gas-filled space of the liquid-gas chamber is connected to a gas pressure detector to obtain the gas pressure P; in the working state, the liquid medicine flows along the path of the inlet pipe → the liquid-gas chamber → the outlet pipe; the inlet flow rate Q of the inlet pipe is obtained based at least on the gas pressure P. in The liquid flow rate Q of the liquid outlet pipeline out The flow difference ΔQ; adjusting the inlet flow rate Q based on the flow difference AQ in and calculating the outlet flow rate Q of the outlet flow line based on the adjusted inlet flow rate Q of the inlet flow line and the flow difference AQ newly acquired after the adjustment in out .​ 2. The flow detection device according to claim 1, characterized in that: A mapping relationship between the gas pressure P and the flow rate difference ΔQ is established in advance. In the working state, based on the mapping relationship and the gas pressure P, the liquid inlet flow rate Q is adjusted in .

3. The flow detection device according to claim 2, characterized in that: It is also equipped with a gas temperature detector that is connected to the gas-filled space of the liquid-gas chamber to obtain the gas temperature T. A mapping relationship between the gas pressure P and the flow rate difference Q at different gas temperatures T is established in advance; In the working state, based on the measured gas temperature T, and the mapping relationship corresponding to the gas temperature T and the gas pressure P, the liquid inlet flow rate Q is adjusted in .

4. The flow detection device according to any one of claims 1-3, characterized in that: In operation, the cross-sectional area of ​​the gas-filled portion of the liquid-gas chamber along the liquid surface is smaller than the cross-sectional area of ​​the liquid-filled portion along the liquid surface.

5. The flow detection device according to any one of claims 1-3, characterized in that: At least based on the specified flow rate Q of the outlet pipeline mean The initial gas volume V0 filling the liquid-gas chamber is set in the pre-operation state.

6. The flow detection device according to claim 5, characterized in that: V0 = 1.6 Q mean .

7. The flow detection device according to claim 6, characterized in that: ΔQ = 1 / 8V0.

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