Mass flow sensor and shell thereof
By designing a mass flow sensor housing with large diameter segments and small diameter segments, the compression acceleration of fluid in the small diameter segments is used to form a stable laminar flow, which solves the problem of low measurement accuracy of small flow fluids in the prior art, and achieves higher detection accuracy and stability.
Patent Information
- Application Number
- CN202420176302.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-23
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-01-23
AI Technical Summary
Existing mass flow sensors are prone to turbulence when measuring small flow fluids, resulting in unstable temperature field, which in turn affects detection accuracy.
A housing for a mass flow sensor is designed, and the pipe body includes a connected large diameter segment and small diameter segment. When the fluid flows into the small diameter segment, it is compressed and accelerated, so as to accelerate the fluid speed, thereby forming a stable laminar flow in the small diameter segment. The small-diameter section communicates with the detection flow channel through the drainage inlet and drainage outhole to ensure that the fluid enters the detection flow channel stably and improves the detection accuracy.
By compressing the accelerated fluid, it forms a stable laminar flow in the small diameter segment, which improves the detection accuracy and stability of the mass flow sensor, takes into account the detection accuracy of large and small-range flows, and reduces cost and space requirements.
Smart Images
Figure CN222579355U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of fluid measurement equipment, and in particular to a mass flow sensor and a housing thereof. Background Art
[0002] A mass flow sensor is a device used to measure the mass of liquid or gas flow. Its working principle is to use an external heat source to heat the measured fluid, measure the temperature field changes caused by the fluid flow, and thus measure the mass flow rate of the fluid. In order to ensure the accuracy of the measurement, the mass flow sensor requires that the fluid passing through the temperature field is in a laminar state during measurement. However, in the related art, turbulence will be generated in the flow channel of the mass flow sensor, and the turbulent eddy current will cause the temperature field to be unstable, which in turn leads to large detection errors of the mass flow sensor. Summary of the invention
[0003] Based on this, it is necessary to provide a mass flow sensor and a housing thereof in order to improve the detection accuracy of the mass flow sensor.
[0004] A shell of a mass flow sensor includes a tube body, the tube body includes a large diameter section and a small diameter section connected to each other, the inner diameter of the small diameter section is smaller than the inner diameter of the large diameter section, the outer wall of the small diameter section is provided with a mounting portion for mounting a heating element and a temperature measuring element, the mounting portion is provided with a detection flow channel, the tube wall of the small diameter section is also penetrated by a drainage inlet hole and a drainage outlet hole, the drainage inlet hole and the drainage outlet hole are spaced apart along the axial direction of the small diameter section, and the drainage inlet hole is connected to one end of the detection flow channel, and the drainage outlet hole is connected to the other end of the detection flow channel.
[0005] The technical solution is further described below:
[0006] In one embodiment, the tube body further includes a transition section connected between the large diameter section and the small diameter section, and the inner diameter of the transition section gradually decreases from the large diameter section to the small diameter section.
[0007] In one embodiment, the number of the large diameter segments is two, and the two large diameter segments are respectively connected to two ends of the small diameter segment.
[0008] In one of the embodiments, a grille is provided in the small diameter section, and the grille is located between the drainage inlet hole and the drainage outlet hole.
[0009] In one of the embodiments, a filter screen is disposed in the large diameter section, and the filter screen is disposed at a first end of the large diameter section away from the small diameter section.
[0010] In one of the embodiments, a mounting boss for mounting a heating element and / or a temperature measuring element is convexly provided in the detection flow channel.
[0011] In one of the embodiments, both sides of the mounting boss in the extending direction of the detection channel are provided with flow guiding slopes for guiding the fluid.
[0012] In one embodiment, the large diameter section, the small diameter section and the mounting portion are an integrally formed structure.
[0013] In one embodiment, the ratio of the inner diameter of the small diameter section to the inner diameter of the large diameter section is 1 / 3 to 2 / 3.
[0014] On the other hand, the present application further provides a mass flow sensor, comprising the housing of the mass flow sensor described above.
[0015] The mass flow sensor and its housing, the tube body of the housing includes a large diameter section and a small diameter section connected to each other. Since the inner diameter of the small diameter section is smaller than the inner diameter of the large diameter section, the fluid will be compressed and accelerated when it flows from the large diameter section to the small diameter section, so that the speed of the fluid entering the small diameter section is accelerated, so that the fluid with a small flow rate can also form a stable laminar flow in the small diameter section when passing through the tube body. At the same time, the small diameter section is connected with the detection channel through the drainage inlet hole and the drainage outlet hole, so that the stability of the fluid entering the detection channel is ensured, thereby improving the detection accuracy and stability. In addition, the tube body adopts a combination of a large diameter section and a small diameter section. Compared with the use of a small diameter section throughout the whole process, it not only ensures that the fluid with a small flow rate can also form a stable laminar flow in the tube body, but also does not affect the detection of the fluid with a large flow rate, and takes into account the accuracy of a large range and a small range. In this way, when measuring a fluid with a large flow change span, it is no longer necessary to install multiple flow sensors with different ranges, which reduces costs and saves space. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application.
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0018] In addition, the drawings are not drawn to a 1:1 scale, and the relative sizes of the various elements are drawn only as examples in the drawings and are not necessarily drawn according to the true scale.
[0019] Figure 1 FIG. 1 is a schematic diagram of the structure of a housing of a mass flow sensor according to an embodiment.
[0020] Figure 2 for Figure 1 A top view of the housing of the mass flow sensor shown in FIG.
[0021] Figure 3 for Figure 2 The housing of the mass flow sensor shown in FIG. 1 is a cross-sectional view taken along the BB section.
[0022] Figure 4 for Figure 3 A magnified view of part A in the middle.
[0023] Description of reference numerals:
[0024] 10. Pipe body; 11. Large diameter section; 12. Small diameter section; 13. Transition section; 20. Mounting portion; 21. Detection flow channel; 211. Drainage inlet hole; 212. Drainage outlet hole; 22. Mounting boss; 221. Drainage slope; 31. Grille; 32. Filter. DETAILED DESCRIPTION
[0025] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0026] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.
[0027] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0028] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0029] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0030] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.
[0031] As described in the background technology, the detection accuracy of traditional mass flow sensors varies greatly when measuring fluids with different flow rates. For example, for a mass flow rate of about 200L / min, it can only have good accuracy when detecting fluids with a flow rate of more than 10L / min. When measuring fluids with a flow rate of 0.5L / min-5L / min, the accuracy is poor, resulting in large errors in the measurement results. Therefore, when measuring fluids with a flow rate range of 0.5-200L / min, it is usually necessary to install at least two mass flow sensors with different ranges, resulting in high costs. After extensive research, the inventors found that the fundamental reason is that when the fluid flow rate is small, due to the slow fluid speed, a stable laminar flow cannot be formed, and even turbulence will occur. The turbulent eddy currents will cause the temperature field to be unstable, which in turn leads to large detection errors of the mass flow sensor and cannot meet the use requirements.
[0032] Based on this, the present application provides a housing of a mass flow sensor capable of ensuring the detection progress of the mass flow sensor, specifically, see Figures 1 to 3 The shell of the mass flow sensor of one embodiment includes a tube body 10, and the tube body 10 includes a large diameter section 11 and a small diameter section 12 connected to each other. The inner diameter of the small diameter section 12 is smaller than the inner diameter of the large diameter section 11. The outer wall of the small diameter section 12 is provided with a mounting portion 20 for mounting a heating element and a temperature measuring element. The mounting portion 20 is provided with a detection channel 21. The tube wall of the small diameter section 12 is also penetrated by a drainage inlet hole 211 and a drainage outlet hole 212. The drainage inlet hole 211 and the drainage outlet hole 212 are spaced apart along the axial direction of the small diameter section 12, and the drainage inlet hole 211 is connected to one end of the detection channel 21, and the drainage outlet hole 212 is connected to the other end of the detection channel 21.
[0033] Specifically, during operation, the fluid flows through the large diameter section 11 and the small diameter section 12 in sequence, and part of the fluid flowing through the small diameter section 12 enters the detection channel 21 through the drainage inlet hole 211. The heating element in the detection channel 21 heats the fluid, and the temperature measuring element detects the temperature field change caused by the flow of the fluid, thereby measuring the mass flow rate of the fluid. Finally, the fluid in the detection channel 21 returns to the small diameter section 12 through the drainage outlet hole 212, and the detection is completed in this way.
[0034] In the housing of the mass flow sensor, the tube body 10 includes a large diameter section 11 and a small diameter section 12 connected to each other. Since the inner diameter of the small diameter section 12 is smaller than the inner diameter of the large diameter section 11, the fluid will be compressed and accelerated when flowing from the large diameter section 11 into the small diameter section 12, so that the fluid speed entering the small diameter section 12 is accelerated. In this way, a small flow of fluid can also form a stable laminar flow in the small diameter section 12 when passing through the tube body 10. At the same time, the small diameter section 12 is connected to the detection channel 21 through the drainage inlet hole 211 and the drainage outlet hole 212, so that the fluid entering the detection channel 21 is stable, thereby improving the detection accuracy of the mass flow sensor. In addition, the tube body 10 adopts a combination of a large diameter section 11 and a small diameter section 12. Compared with the use of the small diameter section 12 throughout the entire process, it ensures that the fluid with a small flow rate can form a stable laminar flow in the tube body 10, and does not affect the detection of the fluid with a large flow rate, taking into account the accuracy of both large and small ranges. In this way, when measuring the fluid with a large flow change span, it is no longer necessary to install multiple flow sensors with different ranges, which reduces costs and saves space.
[0035] See also Figure 3In one embodiment, the tube body 10 further includes a transition section 13 connected between the large diameter section 11 and the small diameter section 12, and the inner diameter of the transition section 13 gradually decreases from the large diameter section 11 to the small diameter section 12. In this way, the formation of a shoulder structure between the large diameter section 11 and the small diameter section 12 is avoided, thereby avoiding the occurrence of eddy currents in the shoulder structure and affecting the detection accuracy, thereby allowing the fluid to be compressed more smoothly from the large diameter section 11 to the small diameter section 12, further ensuring that the fluid forms a stable laminar flow after entering the small diameter section 12.
[0036] See also Figure 3 , there are two large diameter sections 11, and the two large diameter sections 11 are connected to the two ends of the small diameter section 12 respectively. That is, the tube body 10 is only reduced in diameter in the corresponding areas of the drainage inlet hole 211 and the drainage outlet hole 212, and the remaining areas can maintain a larger inner diameter, thus taking into account the detection accuracy of large flow fluid and small flow fluid. Furthermore, a transition section 13 is provided between the two large diameter sections 11 and the small diameter section 12, thus further ensuring the smoothness of the fluid in the tube body 10.
[0037] See also Figure 3 In one embodiment, a grille 31 is provided in the small diameter section 12, and the grille 31 is located between the drainage inlet hole 211 and the drainage outlet hole 212. The grille 31 plays a role in stabilizing the flow, and further facilitates the fluid in the small diameter section 12 to form a laminar flow.
[0038] See also Figure 1 as well as Figure 3 A filter screen 32 is provided in the large diameter section 11, and the filter screen 32 is provided at the first end of the large diameter section 11 away from the small diameter section 12. The filter screen 32 is used to filter impurities in the fluid on the one hand, and can also play a certain role in stabilizing the flow on the other hand, further improving the detection accuracy. Preferably, in one embodiment, the mesh number of the filter screen 32 is 60 mesh to 200 mesh, and the filter screen 32 is made of metal.
[0039] See also Figure 3 as well as Figure 4 In one embodiment, a mounting boss 22 is provided in the detection channel 21, and the mounting boss 22 is used to install a heating element and / or a temperature measuring element. Specifically, by providing a mounting boss 22 in the detection channel 21, the fluid in the detection channel 21 can be further compressed and accelerated when passing through the mounting boss 22, so that a laminar flow is formed in the detection channel 21. At the same time, by installing the heating element and / or the temperature measuring element on the mounting boss 22, the fluid can be closer to the heating element and / or the temperature measuring element, thereby improving the heating efficiency and the detection accuracy. Preferably, the heating element can be a heating wire, and the temperature measuring element can be a thermocouple.
[0040] See also Figure 4The mounting boss 22 is provided with flow guiding slopes 221 on both sides in the extension direction of the detection flow channel 21, and the flow guiding slopes 221 are used to guide the fluid to flow more smoothly through the mounting boss 22. That is, the mounting boss 22 is a trapezoidal structure, so that the fluid passes through the mounting boss 22 more smoothly, further improving the detection accuracy.
[0041] Optionally, in one embodiment, the large diameter section 11, the small diameter section 12 and the mounting portion 20 are integrally formed. For example, in one embodiment, the large diameter section 11, the small diameter section 12 and the mounting portion 20 are integrally injection molded, which simplifies the process and increases the strength of the housing structure.
[0042] In one embodiment, the ratio of the inner diameter of the small diameter section 12 to the inner diameter of the large diameter section 11 is 1 / 3 to 2 / 3. Specifically, if the inner diameter of the small diameter section 12 is greater than 2 / 3 of the inner diameter of the large diameter section 11, the small flow fluid cannot form a stable laminar flow in the small diameter section 12, affecting the detection accuracy of the small flow fluid; if the inner diameter of the small diameter section 12 is less than 1 / 3 of the inner diameter of the large diameter section 11, it will hinder the large flow fluid from flowing through the tube body 10, affecting the detection accuracy of the large flow fluid. By configuring the inner diameter of the small diameter section 12 to be 1 / 3 to 2 / 3 of the inner diameter of the large diameter section 11, the detection accuracy of both the small flow fluid and the large flow fluid can be met.
[0043] An embodiment of the present application further provides a mass flow sensor, specifically, the mass flow sensor of one embodiment includes the housing of any of the above embodiments. Further, the mass flow sensor may also include a heating element for heating the fluid and a temperature measuring element for detecting the temperature of the fluid, and the heating element and the temperature measuring element are arranged in the mounting portion 20 of the housing.
[0044] In the mass flow sensor, the tube body 10 of the shell includes a large diameter section 11 and a small diameter section 12 connected to each other. Since the inner diameter of the small diameter section 12 is smaller than the inner diameter of the large diameter section 11, the fluid will be compressed and accelerated when flowing from the large diameter section 11 to the small diameter section 12, so that the fluid speed entering the small diameter section 12 is accelerated, so that the fluid with a small flow rate can also form a stable laminar flow in the small diameter section 12 when passing through the tube body 10. At the same time, the small diameter section 12 is connected to the detection channel 21 through the drainage inlet hole 211 and the drainage outlet hole 212, so that the fluid entering the detection channel 21 is stable, thereby improving the detection accuracy and stability. In addition, the tube body 10 adopts a combination of a large diameter section 11 and a small diameter section 12. Compared with the use of the small diameter section 12 throughout the entire process, it ensures that the fluid with a small flow rate can also form a stable laminar flow in the tube body 10, and does not affect the detection of the fluid with a large flow rate, taking into account the accuracy of both large and small ranges. In this way, when measuring the fluid with a large flow change span, it is no longer necessary to install multiple flow sensors with different ranges, which reduces costs and saves space.
[0045] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0046] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A housing of a mass flow sensor, characterized in that: The invention comprises a tube body, wherein the tube body comprises a large diameter section and a small diameter section connected to each other, the inner diameter of the small diameter section is smaller than the inner diameter of the large diameter section, the outer wall of the small diameter section is provided with a mounting portion for mounting a heating element and a temperature measuring element, the mounting portion is provided with a detection flow channel, the tube wall of the small diameter section is also provided with a drainage inlet hole and a drainage outlet hole, the drainage inlet hole and the drainage outlet hole are spaced apart along the axial direction of the small diameter section, and the drainage inlet hole is connected with one end of the detection flow channel, and the drainage outlet hole is connected with the other end of the detection flow channel.
2. The housing of the mass flow sensor according to claim 1, characterized in that: The pipe body further comprises a transition section connected between the large diameter section and the small diameter section, and the inner diameter of the transition section gradually decreases from the large diameter section to the small diameter section.
3. The housing of the mass flow sensor according to claim 1, characterized in that: The number of the large-diameter sections is two, and the two large-diameter sections are respectively connected to two ends of the small-diameter section.
4. The housing of the mass flow sensor according to claim 1, characterized in that: A grille is arranged in the small diameter section, and the grille is located between the drainage inlet hole and the drainage outlet hole.
5. The housing of the mass flow sensor according to claim 1, characterized in that: A filter screen is arranged in the large diameter section, and the filter screen is arranged at a first end of the large diameter section away from the small diameter section.
6. The housing of the mass flow sensor according to claim 1, characterized in that: A mounting boss for mounting a heating element and / or a temperature measuring element is convexly provided in the detection flow channel.
7. The housing of the mass flow sensor according to claim 6, characterized in that: The mounting boss is provided with flow guiding inclined surfaces for guiding the fluid on both sides in the extending direction of the detection flow channel.
8. The housing of the mass flow sensor according to claim 1, characterized in that: The large-diameter section, the small-diameter section and the mounting portion are an integrally formed structure.
9. The housing of the mass flow sensor according to any one of claims 1 to 8, characterized in that: The ratio of the inner diameter of the small diameter section to the inner diameter of the large diameter section is 1 / 3 to 2 / 3.
10. A mass flow sensor, characterized in that: A housing comprising the mass flow sensor according to any one of claims 1 to 9.