Measuring device and method

Abstract

The invention provides a measuring device and method, and the device comprises a rectangular channel which is filled with a fluid. The rectangular channel comprises a core body, and the core body comprises a low-resistance heating section; the pressure difference adjusting block is arranged on the low-resistance heating section of the core body, a height difference is formed between the pressure difference adjusting block and the low-resistance heating section, and the pressure difference adjusting block and the low-resistance heating section are used for enabling the fluid flowing through the two sides of the pressure difference adjusting block to form a pressure difference; along the flowing direction of the fluid, differential pressure leading-out holes are formed in the core body on the two sides of the differential pressure adjusting block, and the differential pressure leading-out holes are connected with a differential pressure transmitter through a pressure leading-out pipe, so that the pressure of the fluid is led into the differential pressure transmitter. The real flow value of the fluid flowing through the heating section of the core body can be accurately measured.

Description

Technical Field

[0001] The present application belongs to the technical field of fluid flow measurement in rectangular channels, and specifically relates to a measurement device and method. Background Art

[0002] As a typical heat exchange channel for coolant working fluid in reactor fuel assemblies, rectangular channels are often the focus of thermal hydraulic experimental research. In order to simulate the thermal conditions of a typical channel in the core, the core is energized and heat simulation is achieved based on Joule's law. The rectangular channel visualization experiment body is a simulation body that simulates a typical channel in the core. It also needs to take into account the visualization function and be able to withstand a certain pressure and temperature environment (pressure P < 4MPa, temperature T < 250℃).

[0003] For the visualization experiment body, the non-metal visualization material and the metal heating plate that is powered and heated serve as the flow channel boundary, together forming a rectangular channel. At present, the biggest difficulty of the rectangular channel visualization experiment body is that the metal core and non-metal visualization material that need to constitute the rectangular channel cannot be completely formed into a complete integrated structure by welding and bonding. Therefore, for most rectangular channel visualization experiment bodies, there are gaps. When the fluid medium flows through the rectangular channel, it is inevitable that bypass flow and leakage flow will occur between the overlapping gaps in the rectangular channel, thereby affecting the accuracy of the flow measurement of the fluid that actually flows through the core heating section. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present application is to provide a measuring device and method that can accurately measure the true value of the flow rate of the fluid flowing through the core heating section.

[0005] In order to solve the above problem, the present application provides a measuring device in a first aspect, comprising:

[0006] A rectangular channel, wherein a fluid flows into the rectangular channel;

[0007] The rectangular channel includes a core, and the core includes a low-resistance heating section;

[0008] A pressure difference regulating block, wherein the pressure difference regulating block is arranged on the low resistance heating section of the core body, and a height difference is formed between the pressure difference regulating block and the low resistance heating section, so as to form a pressure difference for the fluid flowing through both sides of the pressure difference regulating block;

[0009] Along the flow direction of the fluid, differential pressure outlet holes are opened on the core body on both sides of the differential pressure regulating block. The differential pressure outlet holes are connected to the differential pressure transmitter through a pressure lead pipe to introduce the pressure of the fluid into the differential pressure transmitter.

[0010] Optionally, the length of the pressure difference adjusting block is equal to the width of the core.

[0011] Optionally, there are two pressure difference outlet holes, which are symmetrically arranged with the pressure difference regulating block as the center of symmetry.

[0012] Optionally, the core body further includes a high-resistance heating section, a sleeve is welded to the bottom of the high-resistance heating section of the core body, and the sleeve is used to install a temperature measuring component so that the measuring end of the temperature measuring component is against the bottom of the core body.

[0013] Optionally, at least two groups of the temperature measuring components are arranged along the flow direction of the fluid, and each group includes at least four temperature measuring components arranged along the width direction of the core.

[0014] Optionally, the sleeve is made of extremely low resistance material.

[0015] Optionally, conductive rods are respectively provided at the bottom ends of the low-resistance heating section and the high-resistance heating section of the core.

[0016] A second aspect of the present application provides a measurement method, which uses any of the above-mentioned measurement devices to measure fluid flow, wherein the rectangular channel includes an integrated rectangular channel and a non-integrated rectangular channel, and the measurement method includes:

[0017] The relationship between the flow rate and the pressure difference of the fluid in the integrated rectangular channel is derived according to the Bernoulli equation;

[0018] Obtaining the pressure difference at the point where the fluid in the non-integrated rectangular channel flows through the pressure difference regulating block (2);

[0019] According to the pressure difference of the fluid in the non-integrated rectangular channel and based on the relationship between the flow velocity and the pressure difference of the fluid in the integrated rectangular channel, the flow value of the fluid in the non-integrated rectangular channel is obtained.

[0020] Optionally, the relationship between the flow rate and the pressure difference of the fluid in the integrated rectangular channel is derived according to the Bernoulli equation, including:

[0021] The fluid passes through a changing cross section. Based on the incompressibility of the fluid, the density of the fluid remains unchanged before and after the cross section changes.

[0022] At the same time, since the length of the cross-section change area is short, the distance of the fluid to the reference horizontal plane remains unchanged before and after the cross-section change;

[0023] Based on the principle of conservation of fluid mass before and after the cross-section changes, the relationship between the flow rate and the pressure difference of the fluid is derived according to the Bernoulli equation.

[0024] Optionally, the fluids in the integrated rectangular channel and the non-integrated rectangular channel are both incompressible fluids.

[0025] Beneficial Effects

[0026] The present invention provides a measuring device and method, which sets a pressure difference adjustment block on the upper surface of the core of a non-integrated rectangular channel, so that the fluid before and after the pressure difference adjustment block generates a pressure difference, and the pressure difference is measured by a pressure difference transmitter. The real flow rate flowing through the heating section in the non-integrated rectangular channel is calculated by the measured pressure difference, which can be used to evaluate the degree of bypass flow and leakage caused by the non-integrated rectangular channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an axonometric view of the core of an embodiment of the present application;

[0028] Figure 2 This is a front view of the core of an embodiment of the present application;

[0029] Figure 3 A side view of the core body of an embodiment of the present application;

[0030] Figure 4 This is a schematic diagram of a non-integrated rectangular channel according to an embodiment of the present application;

[0031] Figure 5 For the embodiments of this application Figure 4 A partial enlarged schematic diagram;

[0032] Figure 6 This is a cross-sectional view of a non-integrated rectangular channel according to an embodiment of the present application;

[0033] Figure 7 For the embodiments of this application Figure 6 A partial enlarged schematic diagram;

[0034] Figure 8 This is a schematic diagram of an integrated rectangular channel according to an embodiment of the present application;

[0035] Fig. 9 Schematic diagram of temperature oscillation caused by the contact between the bypass flow and the thermocouple according to an embodiment of the present application.

[0036] The reference numerals are:

[0037] 1. Core; 101. Low resistance heating section; 102. High resistance heating section;

[0038] 2. Differential pressure regulating block;

[0039] 3. Casing;

[0040] 4. Pressure difference outlet hole;

[0041] 5. Temperature measuring parts;

[0042] 6. Conductive rod;

[0043] 7. Main body shell;

[0044] 8. Visual sealing plate. DETAILED DESCRIPTION

[0045] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0047] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0049] See also Figures 1 to 8 As shown, according to an embodiment of the present application, a first aspect provides a measuring device, comprising:

[0050] A rectangular channel, wherein a fluid flows into the rectangular channel;

[0051] The rectangular channel includes a core 1, and the core 1 includes a low-resistance heating section 101;

[0052] The pressure difference regulating block 2 is arranged on the low resistance heating section 101 of the core 1, and a height difference is formed between the pressure difference regulating block 2 and the low resistance heating section 101, so as to form a pressure difference for the fluid flowing through the two sides of the pressure difference regulating block 2;

[0053] Along the flow direction of the fluid, differential pressure outlet holes 4 are opened on the core body 1 on both sides of the differential pressure regulating block 2. The differential pressure outlet holes 4 are connected to the differential pressure transmitter through a pressure lead pipe to introduce the pressure of the fluid into the differential pressure transmitter.

[0054] By setting a pressure difference regulating block 2 on the upper surface of the core 1 of the non-integrated rectangular channel, a pressure difference is generated in the fluid before and after passing through the pressure difference regulating block 2, and the pressure difference is measured by a pressure difference transmitter. The actual flow rate flowing through the heating section in the non-integrated rectangular channel is calculated by the measured pressure difference, which can be used to evaluate the degree of bypass flow and leakage caused by the non-integrated rectangular channel.

[0055] in, Figures 4 to 7 What is shown is a non-integrated rectangular channel, which also includes a main body shell 7 and a visible sealing plate 8. The core 1 and the visible sealing plate 8 are sequentially arranged on the main body shell 7 to form a rectangular channel, and fluid flows in the rectangular channel.

[0056] Specifically, the main body shell 7, the visualization sealing plate 8 and the core 1 are connected by overlapping, extrusion and fastening.

[0057] Specifically, a through hole for the pressure-inducing pipe to pass through is provided on the main body shell 7. One end of the pressure-inducing pipe passes through the through hole on the main body shell 7 and is connected to the pressure difference outlet hole 4, and the other end is connected to the pressure difference transmitter. The fluid before and after the pressure difference regulating block 2 is introduced into the pressure-inducing pipe through the pressure difference outlet hole 4, and then the pressure difference is measured by the pressure difference transmitter.

[0058] Among them, the pressure difference adjusting block 2 is arranged on the low-resistance heating section 101 of the core 1, and a height difference is formed between the pressure difference adjusting block 2 and the low-resistance heating section 101, which is used to form a pressure difference for the fluid flowing through the two sides of the pressure difference adjusting block 2; that is, by arranging the pressure difference adjusting block 2 in the rectangular channel to change the cross-sectional size of the rectangular channel, a pressure difference is generated when the fluid passes through this changed cross-section (the pressure difference here is the difference between the front and rear pressures), and the true flow rate that actually flows through the heating section is calculated based on the pressure difference to eliminate the influence of bypass flow.

[0059] In conventional non-integrated rectangular channels, since it is impossible to arrange measuring equipment inside, the measuring equipment can usually only be arranged in front of the entrance of the rectangular channel, and the flow rate at the entrance is used as the flow value flowing through the heating section. However, in non-integrated rectangular channels, the fluid will seep out from the gaps, resulting in the flow rate flowing through the top of the heating section being less than the total flow rate at the entrance. Therefore, a pressure difference regulating block 2 is arranged in the low-resistance heating section 101 of the core 1, and the true flow rate flowing through the heating section is measured in the area where bypass flow has occurred.

[0060] The length of the pressure difference adjusting block 2 is equal to the width of the core 1 .

[0061] Among them, the length of the pressure difference adjusting block 2 is equal to the width of the core 1, that is, the inlet fluid needs to flow through the pressure difference adjusting block 2 equally so that the pressure change caused by the flow rate change can be accurately captured, ensuring that the pressure value before and after passing through the pressure difference adjusting block 2 can be accurately obtained.

[0062] There are two pressure difference lead-out holes 4, which are symmetrically arranged with the pressure difference regulating block 2 as the symmetry center.

[0063] The core 1 further comprises a high resistance heating section 102 , a sleeve 3 is welded to the bottom of the high resistance heating section 102 of the core 1 , and the sleeve 3 is used to install a temperature measuring element 5 so that the measuring end of the temperature measuring element 5 abuts against the bottom of the core 1 .

[0064] Due to the existence of side leakage in the conventional non-integrated rectangular channel, the fluid contacts the top of the temperature measuring component 5. The fluid evaporates due to the high temperature of the heating plate, and the evaporated liquid continues to enter the top of the temperature measuring component 5 from the gap. Due to the cyclic changes of evaporation-wetting, the temperature of the temperature measuring component 5 will continue to oscillate, and it is impossible to obtain an accurate value.

[0065] Therefore, a sleeve 3 is welded at the bottom of the high-resistance heating section 102 of the core 1, and the measuring end of the temperature measuring element 5 is wrapped around the sleeve 3 to isolate it from the side leakage fluid, while ensuring that the measuring end of the temperature measuring element 1 is in full contact with the high-resistance heating section 102 of the core 1, thereby ensuring the accuracy of the temperature measurement. Since the measuring end of the temperature measuring element 5 is no longer in contact with the side leakage flow, evaporation-wetting will not occur at the top of the measuring end of the temperature measuring element 5, thereby ensuring the stability of the temperature measurement, and solving the problem that the temperature measured by the temperature measuring element 5 continuously oscillates due to the side leakage flow, and the accurate value cannot be obtained.

[0066] Among them, a through hole is also opened on the main body shell 7 for the temperature measuring component 5 to pass through. When the core 1 is installed on the main body shell 7, the sleeve 3 at the bottom of the core 1 is located in the through hole through which the temperature measuring component 5 passes, so that the setting of the sleeve 3 does not interfere with the installation of other structures.

[0067] like Fig. 9 As shown, Fig. 9A schematic diagram of the temperature oscillation caused by the side leakage flow contacting the thermocouple is shown in FIG.

[0068] At least two groups of temperature measuring elements 5 are arranged along the flow direction of the fluid, and each group includes at least four temperature measuring elements 5 arranged along the width direction of the core 1 .

[0069] The temperature measuring element 5 is a thermocouple, and multiple groups of thermocouples are arranged at the bottom of the core 1 to ensure the accuracy of temperature measurement by calculating the average.

[0070] The sleeve 3 is made of extremely low resistance material.

[0071] Among them, the extremely low resistance material includes Ni, Ag, etc. It avoids the phenomenon of uneven heat flow sealing distribution on the upper surface of the core 1, thereby affecting the thermal experiment.

[0072] Conductive rods 6 are respectively provided at the bottom ends of the low-resistance heating section 101 and the high-resistance heating section 102 of the core 1 .

[0073] Among them, the conductive rod 6 is a conductive copper rod, through which the current is conducted to the low resistance heating section 101 and the high resistance heating section 102 of the core 1, wherein the low resistance heating section 101 and the high resistance heating section 102 are connected in series. Due to the difference in resistance characteristics, the heat is concentrated in the high resistance heating section 102. When the fluid passes through the high resistance heating section 102, the heat will be conducted from the high resistance heating section 102 to the fluid.

[0074] Among them, through holes for the conductive rod 6 to pass through are also opened at both ends of the main body shell 7. When the core 1 is installed on the main body shell 7, the conductive rod 6 at the bottom of the core 1 is located in the through hole on the main body shell 7 for the conductive rod 7 to pass through.

[0075] Another aspect of this embodiment provides a measurement method, using any one of the above measurement devices to measure fluid flow, the rectangular channel includes an integrated rectangular channel and a non-integrated rectangular channel, the measurement method includes:

[0076] S1: The relationship between the flow rate and pressure difference of the fluid in the integrated rectangular channel is derived based on the Bernoulli equation;

[0077] Here, the fluid medium is selected as incompressible water medium due to its incompressible characteristics, based on the Bernoulli equation:

[0078]

[0079] Where P is pressure; C is the correction factor used when calculating kinetic energy based on average flow velocity; ρ is fluid density; v is flow velocity; Z is the distance of the fluid from the reference horizontal plane; g is the acceleration due to gravity;

[0080] When the water medium passes through the pressure difference regulating block 2 (i.e., through the changed cross section), since the fluid is incompressible, the fluid density remains unchanged before and after the changed cross section, i.e., ρ 前 =ρ 后 ;

[0081] At the same time, based on the short length of the cross-sectional change area, the distance of the fluid to the reference horizontal plane remains unchanged before and after the cross-sectional change, that is, Z 前 =Z 后 ;

[0082] Therefore, after the fluid passes through the variable cross-section, formula (1) can be simplified to:

[0083]

[0084] According to the law of conservation of mass, we have

[0085] A before v before = A 后 vAfter (3)

[0086] Among them, A 前 is the flow area before the cross-section changes; A 后 is the flow area after the cross section changes;

[0087] Formula (2) and formula (3) are combined to obtain the relationship between flow rate and pressure difference:

[0088]

[0089] Where △P is the pressure difference, △P=P 后 -P 前 .

[0090] S2: Obtaining the pressure difference at the point where the fluid in the non-integrated rectangular channel flows through the pressure difference regulating block 2;

[0091] The pressure difference △P before and after the fluid in the non-integrated rectangular channel flows through the pressure difference regulating block 2 is obtained by a pressure difference transmitter;

[0092] S3: according to the pressure difference of the fluid in the non-integrated rectangular channel, based on the relationship between the flow velocity and the pressure difference of the fluid in the integrated rectangular channel, the flow rate value of the fluid in the non-integrated rectangular channel is obtained;

[0093] Specifically, the pressure difference obtained by the pressure difference transmitter in S2 is substituted into the relationship between flow velocity and pressure difference to calculate the flow velocity value of the fluid; and then the actual flow value is calculated based on the fact that the flow rate is equal to the product of the flow velocity and the cross-sectional area.

[0094] It can be seen that by calibrating with an integrated rectangular channel with the same structure as the core 1, the relationship between the fluid flow rate and the pressure difference can be obtained. Based on the numerical relationship obtained by calibration, the actual flow rate flowing through the heating section can be measured to eliminate the influence of the bypass flow.

[0095] The fluids in the integrated rectangular channel and the non-integrated rectangular channel are both incompressible fluids.

[0096] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0097] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A measuring device, characterized in that: include: A rectangular channel, wherein a fluid flows into the rectangular channel; The rectangular channel comprises a core (1), and the core (1) comprises a low-resistance heating section (101); a pressure difference regulating block (2), the pressure difference regulating block (2) being arranged on the low resistance heating section (101) of the core (1), and forming a height difference between the pressure difference regulating block (2) and the low resistance heating section (101), so as to form a pressure difference between the fluid flowing through the two sides of the pressure difference regulating block (2); Along the flow direction of the fluid, differential pressure outlet holes (4) are provided on the core body (1) on both sides of the differential pressure regulating block (2); the differential pressure outlet holes (4) are connected to the differential pressure transmitter via a pressure guide pipe, so as to introduce the pressure of the fluid into the differential pressure transmitter.

2. A measuring device according to claim 1, characterized in that: The length of the pressure difference adjustment block (2) is equal to the width of the core (1).

3. A measuring device according to claim 1, characterized in that: There are two pressure difference lead-out holes (4), which are symmetrically arranged with the pressure difference adjustment block (2) as the symmetry center.

4. A measuring device according to claim 1, characterized in that: The core (1) further comprises a high-resistance heating section (102); a sleeve (3) is welded to the bottom of the high-resistance heating section (102) of the core (1); the sleeve (3) is used to install a temperature measuring component (5) so that the measuring end of the temperature measuring component (5) abuts against the bottom of the core (1).

5. A measuring device according to claim 4, characterized in that: At least two groups of the temperature measuring components (5) are arranged along the flow direction of the fluid, and each group has at least four temperature measuring components (5) arranged along the width direction of the core (1).

6. A measuring device according to claim 4, characterized in that: The sleeve (3) is made of extremely low-resistance material.

7. A measuring device according to claim 4, characterized in that: Conductive rods (6) are respectively provided at the bottom ends of the low-resistance heating section (101) and the high-resistance heating section (102) of the core (1).

8. A measurement method, characterized in that: The measuring device according to any one of claims 1 to 6 is used to measure fluid flow, the rectangular channel includes an integrated rectangular channel and a non-integrated rectangular channel, and the measuring method includes: The relationship between the flow rate and the pressure difference of the fluid in the integrated rectangular channel is derived according to the Bernoulli equation; Obtaining the pressure difference at the point where the fluid in the non-integrated rectangular channel flows through the pressure difference regulating block (2); According to the pressure difference of the fluid in the non-integrated rectangular channel and based on the relationship between the flow velocity and the pressure difference of the fluid in the integrated rectangular channel, the flow value of the fluid in the non-integrated rectangular channel is obtained.

9. A measuring method according to claim 8, characterized in that: The relationship between the flow rate and the pressure difference of the fluid in the integrated rectangular channel is derived according to the Bernoulli equation, including: The fluid passes through a changing cross section. Based on the incompressibility of the fluid, the density of the fluid remains unchanged before and after the cross section changes. At the same time, since the length of the cross-section change area is short, the distance of the fluid to the reference horizontal plane remains unchanged before and after the cross-section change; Based on the principle of conservation of fluid mass before and after the cross-section changes, the relationship between the flow rate and the pressure difference of the fluid is derived according to the Bernoulli equation.

10. A measuring method according to claim 8, characterized in that: The fluids in the integrated rectangular channel and the non-integrated rectangular channel are both incompressible fluids.

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