Liquid flow velocity measuring device and measuring method

Abstract

The invention mainly relates to the technical field of nuclear power reactors, in particular to a liquid flow velocity measuring device and method. The device comprises a calculation module, a fluid temperature measurement module, a heat insulation layer, a rib column, and a first temperature measurement point, a second temperature measurement point and a third temperature measurement point which are fixed on the rib column, the fluid temperature measuring module is used for measuring the temperature of fluid in a to-be-measured flow channel, the rib column is fixed to the wall face of the to-be-measured flow channel through the heat insulation layer, the first temperature measuring point is inserted into the to-be-measured flow channel, and the second temperature measuring point is located at the position of the inner edge of the wall face. The third temperature measuring point is positioned on the outer side of the runner to be measured; and the calculation module is used for calculating the flow velocity of the fluid according to the temperature of the first temperature measuring point, the temperature of the second temperature measuring point and the temperature of the fluid. The device can be applied to liquid low-flow-velocity measurement in a high-temperature and high-pressure environment.

Description

Technical Field

[0001] The invention mainly relates to the technical field of nuclear power reactors, and in particular to a liquid flow rate measuring device and a measuring method. Background Art

[0002] At present, my country is carrying out the construction of new types of advanced reactors. Many designs of these reactors are realized through natural circulation, such as cooling of the containment, cooling of the core, etc. The driving force of the natural circulation reactor is the height difference of the cold and heat sources and the density difference of the fluid. The flow rate of natural circulation is much smaller than that of the forced circulation reactor. At present, the commonly used flow meters on the market include electromagnetic flow meters, differential pressure flow meters, turbine flow meters and other types of flow meters. The lowest measurement flow rate of these commonly used flow meters can generally only reach the lower limit of 0.3m / s when they are designed, which is far beyond the upper limit of the natural circulation flow rate.

[0003] In addition, small reactors generally adopt a compact design, and the location where flow meters can be installed is usually not a conventional circular pipe. The commonly used pipeline flow meters on the market cannot be directly installed on this type of reactor. In addition, the pressure and temperature of the reactor are relatively high, which exceeds the applicable range of most flow meters on the market.

[0004] Therefore, it is necessary to design and develop a device for measuring low flow rates at high temperature and high pressure. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a device and a method for measuring low flow rate suitable for high temperature and high pressure.

[0006] To solve the above technical problems, the present invention provides a liquid flow rate measuring device, comprising a calculation module, a fluid temperature measuring module, an insulation layer, a rib column, and a first temperature measuring point, a second temperature measuring point and a third temperature measuring point fixed on the rib column; the fluid temperature measuring module is used to measure the temperature of the fluid in the flow channel to be measured, the rib column is fixed on the wall surface of the flow channel to be measured through the insulation layer, the first temperature measuring point is inserted into the flow channel to be measured, the second temperature measuring point is located at the inner edge of the wall surface, and the third temperature measuring point is located on the outside of the flow channel to be measured; the calculation module is used to calculate the flow rate of the fluid according to the temperature of the first temperature measuring point, the temperature of the second temperature measuring point and the temperature of the fluid.

[0007] Optionally, the flow rate of the fluid is calculated by the following formula:

[0008]

[0009] Where, u is the flow rate of the fluid, k is the coefficient, t f is the temperature of the fluid, tH is the temperature of the first temperature measuring point, t0 is the temperature of the second temperature measuring point, and f() is a logical function.

[0010] Optionally, the rib is a heat-conducting material with equal cross-sectional area at any point.

[0011] Optionally, the rib column is a cylinder or a cuboid.

[0012] Optionally, the surface heat transfer resistance of the rib column is much greater than the heat conduction resistance in the rib column, and the temperature of the rib column in any cross section is uniform.

[0013] Optionally, the rib is made of metal material.

[0014] Optionally, the thermal insulation layer is a layer of vacuum or a layer of air or other inert gas.

[0015] Optionally, it further includes: a constant temperature module, which is used to ensure that the temperature of the third temperature measurement point remains unchanged during the measurement process.

[0016] Optionally, the first temperature measuring point, the second temperature measuring point and the third temperature measuring point are thermocouples or thermal resistors.

[0017] To solve the above technical problems, the present invention provides a liquid flow rate measurement method, comprising: measuring the temperature of the fluid in the flow channel to be measured; obtaining the temperature of a first temperature measuring point and a second temperature measuring point of the liquid flow rate measurement device of the present application; and calculating the flow rate of the fluid based on the temperature of the first temperature measuring point, the temperature of the second temperature measuring point and the temperature of the fluid.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention can be used for measuring low flow rates of liquids. Conventional measurement methods are often unable to measure when the flow rate of the liquid is lower than 0.3 m / s. The present device can measure flow rates lower than 0.3 m / s.

[0020] 2. The present invention can be applied to the measurement of flow velocity in high temperature and high pressure environments. The present invention has a simple structure and a strong pressure bearing capacity and can withstand a high pressure of 10-20 MPa (a) and a high temperature of 300°C.

[0021] 3. The present invention has a simple structure and no moving parts. The only measuring element is a fluid temperature measuring module, which is not easily damaged during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0023] Figure 1 is a schematic diagram of a liquid flow rate measuring device according to an embodiment of the present invention.

[0024] Figure 2 4 is a schematic diagram of a liquid flow rate measurement principle according to an embodiment of the present invention.

[0025] Figure 3 is a flow chart of a method for measuring liquid flow rate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0027] For small integrated natural circulation reactors, the driving force of natural circulation reactors is the height difference of cold and heat sources and the density difference of fluids, and the flow rate inside the pipeline is generally low. Commonly used flow meters often cannot measure when the flow rate of the liquid is lower than 0.3m / s; in addition, small reactors generally adopt a compact design, and the location for installing flow meters is usually not a conventional circular pipe. Commonly used pipeline flow meters on the market cannot be directly installed on this type of reactor. In addition, the pressure and temperature of the reactor are relatively high, which exceeds the applicable range of most flow meters on the market.

[0028] Therefore, it is necessary to design and develop a new type of liquid flow rate measuring device, which should have the following three characteristics at the same time:

[0029] 1. Able to measure smaller flow rates, suitable for the flow rate range of fluids under natural circulation conditions;

[0030] 2. It can be installed in special-shaped pipes instead of common round pipes;

[0031] 3. The structure can withstand high temperature and high pressure.

[0032] Figure 1 Schematic diagram of a liquid flow rate measuring device according to an embodiment of the present invention. Figure 1As shown, the liquid flow rate measuring device 100 includes: a rib column 4, a first temperature measuring point 1, a second temperature measuring point 2 and a third temperature measuring point 3 fixed on the rib column 4, an insulation layer 5, a fluid temperature measuring module and a calculation module (not shown).

[0033] The fluid temperature measurement module is used to measure the temperature of the fluid in the flow channel to be measured. The rib column 4 is fixed on the wall L of the flow channel to be measured through the insulation layer 5. The first temperature measuring point 1 is inserted into the flow channel to be measured, the second temperature measuring point 2 is located at the inner edge of the wall L, and the third temperature measuring point 3 is located on the outside of the flow channel to be measured.

[0034] The calculation module is used to calculate the flow rate of the fluid according to the temperature of the first temperature measurement point, the temperature of the second temperature measurement point and the temperature of the fluid.

[0035] Figure 2 1 is a schematic diagram of a liquid flow rate measurement principle according to an embodiment of the present invention. Figure 2 As shown, u is the flow rate of the fluid, t f is the temperature of the fluid, t H is the temperature of the first temperature measuring point, and t0 is the temperature of the second temperature measuring point.

[0036] This measurement is based on the following assumptions:

[0037] 1. The thermal conductivity and surface heat transfer coefficient of the rib column are constant, and the cross-sectional area of ​​the rib column remains unchanged;

[0038] 2. The heat transfer resistance of the rib column surface is much greater than the heat conduction resistance in the rib column, and the temperature of the rib column in any cross section is uniform;

[0039] 3. The heat dissipation of the end section of the rib column is negligible, that is, the end section of the rib column is considered to be insulated.

[0040] The measurement principle of this device is based on the relevant principles of heat transfer, such as Figure 1 and Figure 2 As shown, the rib column 4 is fixed to the wall L of the flow channel to be measured through the insulation layer 5, wherein one end of the rib column 4 is inserted into the fluid to be measured, and the other end is exposed to the external environment. At this time, the temperature of the fluid is higher than the temperature of the external environment. According to the principle of heat transfer, the heat of the fluid will be transferred to the inserted rib column through convection heat transfer, and then transferred to the end exposed to the external environment through the rib column. At this time, the temperature t of the first temperature measurement point can be measured. H , the temperature t0 of the second temperature measuring point, and the temperature t f (It must be measured by another fluid temperature measurement module.) Optionally, the fluid temperature measurement module is a thermocouple.

[0041] The heat is transferred between the ribs inserted into the fluid and the fluid through convection heat transfer. The heat entering the ribs is then transferred to the rib root and rib tail through the heat conduction of the ribs. For a rib with a fixed cross-sectional area, a single material, and a known temperature fluid. The heat transfer Q1 between the rib end and the fluid is a quantity related to the fluid flow rate u, Q1 = f(u), and when Q1 enters the rib, it will cause the temperature t of the first temperature measuring point to increase. H Increases, at which time the temperature t H is a function related to Q1 and the rib tail temperature T3, that is, t H =f(Q1, T3). After entering the rib column, the heat continues to be transferred to the rib root through the heat conduction inside the rib column, causing the temperature t0 of the second temperature measuring point to rise. Due to the existence of the insulation layer 5, the temperature t0 of the second temperature measuring point is only related to the heat exchange amount Q1 and the temperature T3 of the rib tail, that is, t0 = f(Q1, T3).

[0042] During the measurement, since the temperature of the external environment remains constant, the temperature at T3 also remains constant. H and t0 are only related to the heat transfer Q1. Since Q1 is a function related to the fluid flow rate u, t H and t0 are also only related to the flow velocity u of the fluid. H and t0 and t f The flow velocity u of the flow channel can be obtained by calculating the temperature.

[0043] Optionally, the flow rate of the fluid is calculated by the following formula:

[0044]

[0045] Where u is the flow velocity of the fluid, k is the coefficient, and t f is the temperature of the fluid, t H is the temperature of the first temperature measuring point, t0 is the temperature of the second temperature measuring point, and f() is a logical function.

[0046] Optionally, the rib column is a heat-conducting material with equal cross-sectional area at any point. The shape of the rib column includes but is not limited to a cylinder or a cuboid.

[0047] To ensure accurate flow rate measurement:

[0048] Optionally, the ribs are made of metal material with good thermal conductivity.

[0049] Optionally, the insulation layer is a layer of vacuum or a layer of air or other inert gas.

[0050] Optionally, the first temperature measuring point, the second temperature measuring point and the third temperature measuring point are high-precision thermocouples or thermal resistors.

[0051] In order to ensure better accuracy, the temperature T3 of the rib tail should be kept consistent. Optionally, the liquid flow rate measuring device further comprises a constant temperature module, which is used to ensure that the temperature of the third temperature measuring point remains unchanged during the measurement process.

[0052] Figure 3 FIG. 1 is a flow chart of a method for measuring liquid flow rate according to an embodiment of the present invention. Figure 3 As shown, the liquid flow rate measurement method 300 includes:

[0053] Step S31: measuring the temperature of the fluid in the flow channel to be measured;

[0054] Step S32: obtaining the temperature of the first temperature measuring point and the temperature of the second temperature measuring point of the liquid flow rate measuring device of the present application;

[0055] Step S33: Calculate the flow rate of the fluid according to the temperature of the first temperature measuring point, the temperature of the second temperature measuring point and the temperature of the fluid.

[0056] Optionally, the flow rate of the fluid is calculated by the following formula:

[0057]

[0058] Where u is the flow velocity of the fluid, k is the coefficient, and t f is the temperature of the fluid, t H is the temperature of the first temperature measuring point, t0 is the temperature of the second temperature measuring point, and f() is a logical function.

[0059] Compared with the existing technology, the technical solution of the present invention has the following advantages:

[0060] 1. The present invention can be used for measuring low flow rates of liquids. Conventional measurement methods are often unable to measure when the flow rate of the liquid is lower than 0.3 m / s. The present device can measure flow rates lower than 0.3 m / s.

[0061] 2. The present invention can be applied to the measurement of flow velocity in high temperature and high pressure environments. The present invention has a simple structure and a strong pressure bearing capacity and can withstand a high pressure of 10-20 MPa (a) and a high temperature of 300°C.

[0062] 3. The present invention has a simple structure and no moving parts. The only measuring element is a fluid temperature measuring module, which is not easily damaged during use.

[0063] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0064] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0065] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0066] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0067] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0068] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0069] It should be understood that when a component is referred to as being "on another component," "connected to another component," "coupled to another component," or "contacting another component," it may be directly on, connected to, coupled to, or contacting the other component, or there may be intervening components. In contrast, when a component is referred to as being "directly on another component," "directly connected to," "directly coupled to," or "directly contacting" another component, there are no intervening components. Similarly, when a first component is referred to as being "electrically in contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between conductive components.

[0070] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of the present application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the subject of the present application requires more features than the features mentioned. In fact, the features of the embodiment are less than all the features of the single embodiment disclosed above.

[0071] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining the digits. Although the numerical domains and parameters used to confirm the breadth of the range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0072] As shown in this application, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0073] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0074] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the present application.

Claims

1. A liquid flow rate measuring device, characterized in that: include: A calculation module, a fluid temperature measurement module, an insulation layer, a rib column, and a first temperature measurement point, a second temperature measurement point, and a third temperature measurement point fixed on the rib column; The fluid temperature measurement module is used to measure the temperature of the fluid in the flow channel to be measured, the rib column is fixed on the wall surface of the flow channel to be measured through the insulation layer, the first temperature measurement point is inserted into the flow channel to be measured, the second temperature measurement point is located at the inner edge of the wall surface, and the third temperature measurement point is located outside the flow channel to be measured; The calculation module is used to calculate the flow rate of the fluid according to the temperature of the first temperature measurement point, the temperature of the second temperature measurement point and the temperature of the fluid.

2. The liquid flow rate measuring device according to claim 1, characterized in that: The flow rate of the fluid is calculated by the following formula: Wherein, u is the flow velocity of the fluid, k is the coefficient, t f is the temperature of the fluid, t H is the temperature of the first temperature measuring point, t0 is the temperature of the second temperature measuring point, and f() is a logical function.

3. The liquid flow rate measuring device according to claim 1, characterized in that: The rib column is a heat-conducting material with equal cross-sectional area at any point.

4. The liquid flow rate measuring device according to claim 3, characterized in that: The rib column is a cylinder or a cuboid.

5. The liquid flow rate measuring device according to claim 3, characterized in that: The surface heat transfer resistance of the rib column is much greater than the heat conduction resistance in the rib column, and the temperature of the rib column in any cross section is uniform.

6. The liquid flow rate measuring device according to claim 3, characterized in that: The rib column is made of metal material.

7. The liquid flow rate measuring device according to claim 1, characterized in that: The heat insulating layer is a layer of vacuum or a layer of air or other inert gas.

8. The liquid flow rate measuring device according to claim 1, characterized in that: Also includes: A constant temperature module, wherein the constant temperature module is used to ensure that the temperature of the third temperature measurement point remains unchanged during the measurement process.

9. The liquid flow rate measuring device according to claim 1, characterized in that: The first temperature measuring point, the second temperature measuring point and the third temperature measuring point are thermocouples or thermal resistors.

10. A method for measuring liquid flow rate, characterized in that: include: Measuring the temperature of the fluid in the flow channel to be tested; Acquire the temperature of a first temperature measuring point and the temperature of a second temperature measuring point of the liquid flow rate measuring device according to any one of claims 1 to 8; The flow rate of the fluid is calculated according to the temperature of the first temperature measurement point, the temperature of the second temperature measurement point, and the temperature of the fluid.

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