Laminar flow meter

Abstract

The invention discloses a laminar flow meter, and relates to the technical field of flow meters. The vibration column is used for triggering the cavitation effect to generate bubbles, the luminous body, the optical splitter and the image sensor are combined, flow velocity distribution is detected through bubble shadow motion, and the flow is accurately calculated; the adjustable light path system consists of a convex lens and a concave lens, and flexibly adapts to different fluid characteristics by adjusting a screw rod; the efficient heat dissipation system adopts cooling liquid circulation and active ventilation, so that long-time stable operation is ensured; the modular design facilitates disassembly and maintenance, and the practicability is enhanced. Compared with a traditional flow meter, the low-speed laminar flow measurement precision, the light path adaptability, the heat dissipation efficiency and the maintenance convenience of the equipment are remarkably improved, and the equipment is suitable for flow monitoring requirements under various working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of flow meters, and particularly to a laminar flow meter. Background Art

[0002] Most of the existing laminar flow meters adopt mechanical or thermal measurement methods, such as differential pressure flow meters or hot wire anemometers. The differential pressure flow meter calculates the flow velocity by measuring the pressure difference before and after the pipeline, but its sensitivity to low-speed laminar flow is low, and the installation is complex. A throttling device needs to be set in the pipeline, and it is easily affected by the fluid viscosity, resulting in an increase in error. The hot wire anemometer measures the flow velocity through the heat exchange between the heating element and the fluid. Although it is sensitive to low-speed flow, its measurement result is easily disturbed by temperature fluctuations, and the element is prone to aging after long-term use, and the maintenance cost is relatively high. In addition, these devices usually lack the ability to directly observe the flow velocity distribution, and can only provide a rough estimate of the average flow rate, which cannot meet the application scenarios that require precise analysis of the laminar velocity profile. Summary of the Invention

[0003] To overcome the defects of the above-mentioned prior art, the present invention provides the following technical solution: A laminar flow meter, including a support light-shielding plate and a light-shielding housing fixedly installed on both sides of the outer surface of the transparent measurement chamber. A rectangular hole is provided on the support light-shielding plate, and a spectroscope fixedly matched with the outer surface of the transparent measurement chamber is arranged in the rectangular hole. A light shaping window is arranged on one side of the inner wall of the light-shielding housing facing the transparent measurement chamber, and a light-emitting body support is fixed on the side of the light-shielding housing away from the transparent measurement chamber. A light-emitting body is fixedly installed on the light-emitting body support, wherein the light shaping window is used to shape the light emitted by the light-emitting body into a rectangular light spot with the same shape and size as the rectangular hole provided on the support light-shielding plate; an image sensor is arranged on the side of the spectroscope away from the transparent measurement chamber, and the image sensor is used to receive the light emitted by the light-emitting body, wherein the light received by the image sensor is the light emitted by the light-emitting body divided into multiple parallel light spots by the spectroscope.

[0004] Preferably, a concave lens is fixedly installed on one side of the inner wall of the light-shielding housing located in the transparent measurement chamber. A convex lens frame is arranged between the opposite surface of the concave lens and the light-emitting body, and the convex lens frame is slidably matched with the inner wall of the light-shielding housing, and a convex lens is fixedly installed on the convex lens frame.

[0005] Preferably, the convex lens and the concave lens are used to adjust the light emitted by the light-emitting body into a parallel light beam. The convex lens frame is slidably installed on a guiding slide bar, and the guiding slide bar is fixed on the light-shielding housing and the light-emitting body support. An adjusting screw rod is also rotatably arranged on the light-emitting body support, and the adjusting screw rod is in threaded transmission cooperation with the convex lens frame for adjusting the distance between the convex lens and the concave lens. A locking screw is also threadedly installed on the light-emitting body support, and the locking screw is used to fix the adjusting screw rod and the light-emitting body support.

[0006] Preferably, an image sensor mounting frame is fixedly installed on the support light-shielding plate. The image sensor mounting frame is used to wrap the beam splitter. An image sensor is fixedly installed on the image sensor mounting frame. An image sensor heat conducting plate is fixedly installed on the image sensor mounting frame. A thermal grease is provided between the image sensor heat conducting plate and the image sensor. Two symmetrically arranged image sensor heat sinks are fixedly installed on the side of the transparent measurement chamber. The two image sensor heat sinks are thermally connected to the image sensor heat conducting plate through an image sensor temperature conducting tube.

[0007] Preferably, a light emitter evaporation chamber is arranged between the two image sensor heat sinks. The light emitter evaporation chamber is fixedly connected to the transparent measurement chamber. A light emitter condensation heat sink is fixedly and sealedly installed on the light emitter evaporation chamber. A light emitter heat conducting plate is fixedly attached to the light emitter support. The light emitter heat conducting plate is fixedly connected to the inside of the light emitter evaporation chamber through an evaporation temperature conducting tube.

[0008] Preferably, two adapter joints are fixedly connected to both ends of the transparent measurement chamber in a manner that is convenient for disassembly. Two symmetrically arranged protective shells are sleeved outside the transparent measurement chamber. An exhaust port is provided on one of the protective shells, and an intake fan is fixedly arranged on the other protective shell. The intake fan, the exhaust port, the image sensor heat sinks, and the light emitter condensation heat sinks are aligned.

[0009] Preferably, an inner accessory transparent tube is fixedly installed on the inner wall of the transparent measurement chamber in a manner that is convenient for disassembly. The inner accessory transparent tube and the transparent measurement chamber are fixedly connected through studs. The outer surface of the inner accessory transparent tube and the inner wall of the transparent measurement chamber are in sliding seal fit.

[0010] Preferably, the inner wall of the inner accessory transparent tube and the corresponding position of the beam splitter are arranged in a plane, and the plane is in a stepped shape to prevent the light from shifting after passing through the inner accessory transparent tube. The beam splitter is composed of multiple parallel light-impermeable aluminum foil plates, so that multiple equidistant and evenly distributed gaps are formed on the beam splitter.

[0011] Preferably, a vibration column is fixedly installed at the end of the inner wall of the transparent measurement chamber. The vibration column is located in the flow direction of the fluid inside the transparent measurement chamber and is used to drive the fluid to vibrate, so that the fluid generates bubbles through the cavitation effect, and the generated bubbles pass between the light shaping window and the beam splitter.

[0012] The present invention has the following beneficial effects compared with the prior art: (1) By generating bubbles with a vibration column and combining a spectroscope and an image sensor, the present invention can accurately measure the velocity distribution of a fluid in a transparent measurement chamber. The spectroscope divides light into multiple parallel light spots, and the image sensor detects the movement speed of the bubble shadows frame by frame to obtain the flow velocity of each layer of fluid. This design makes full use of the parabolic distribution characteristic of the laminar flow velocity. Only half of the fluid velocity needs to be measured to calculate the overall flow rate, improving the measurement accuracy and efficiency compared with traditional flow meters, and is particularly suitable for low-speed laminar flow scenarios; (2) By adjusting the screw rod to drive the convex lens frame to slide, and cooperating with the convex lens and the concave lens, the user can flexibly adjust the light emitted by the light-emitting body to form a parallel light beam or change the light spot range. This design can optimize the light intensity and coverage area according to the fluid transparency or measurement requirements, avoiding measurement errors caused by light divergence or excessive intensity, ensuring that the light signal received by the image sensor is stable and clear, and significantly improving the adaptability of the device to different fluid properties; (3) The heat generated when the light-emitting body and the image sensor work is efficiently conducted and dissipated through the light-emitting body heat conducting plate, evaporation heat conducting tube, light-emitting body condensation heat sink, and the image sensor heat conducting plate, heat conducting tube, and heat sink. The evaporation and condensation mechanism of the coolant in a negative pressure environment further improves the heat dissipation efficiency. Combined with the ventilation design of the intake fan and the exhaust port, it ensures the stability of the device during long-term operation and avoids performance degradation or shortened lifespan caused by overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0014] Figure 2 It is a schematic diagram of the structure of the adapter of the present invention.

[0015] Figure 3 It is a schematic diagram of the structure at the support light-shielding plate of the present invention.

[0016] Figure 4 It is a schematic diagram of the structure at the light-emitting body evaporation chamber of the present invention.

[0017] Figure 5 It is a schematic diagram of the structure at the spectroscope of the present invention.

[0018] Figure 6 For the present invention Figure 5 Schematic diagram of the structure at position A in

[0019] Figure 7 It is a schematic diagram of the cross-sectional structure of the inner accessory transparent tube of the present invention.

[0020] Figure 8 It is a diagram of the installation position of the vibration column of the present invention.

[0021] In the figure: 101 - transparent measurement chamber; 102 - adapter; 103 - protective housing; 104 - intake fan; 105 - exhaust port; 106 - support light-shielding plate; 107 - image sensor mounting frame; 108 - image sensor heat conducting plate; 109 - image sensor heat sink; 110 - image sensor temperature conducting tube; 111 - image sensor; 112 - beam splitter; 113 - light emitter condensation heat sink; 114 - light emitter evaporation chamber; 115 - evaporation temperature conducting tube; 116 - light emitter heat conducting plate; 117 - light emitter bracket; 118 - light-shielding housing; 119 - adjusting lead screw; 120 - light emitter; 121 - locking screw; 122 - guiding slide bar; 123 - convex lens frame; 124 - convex lens; 125 - concave lens; 126 - light shaping window; 127 - inner fitting transparent tube; 128 - stud; 129 - vibration column. Specific implementation manner

[0022] The following combines the appended Figures 1-8 drawings, and further illustrates the technical solution of the present invention through specific implementation manners.

[0023] The present invention provides a laminar flowmeter, which includes a support light-shielding plate 106 and a light-shielding housing 118 fixedly installed on both sides of the outer surface of a transparent measurement chamber 101. A rectangular hole is formed in the support light-shielding plate 106, and a spectroscope 112 fixedly engaged with the outer surface of the transparent measurement chamber 101 is disposed in the rectangular hole. A light shaping window 126 is provided on one side of the inner wall of the light-shielding housing 118 facing the transparent measurement chamber 101. A light-emitting body support 117 is fixed on the side of the light-shielding housing 118 away from the transparent measurement chamber 101, and a light-emitting body 120 is fixedly installed on the light-emitting body support 117. The light shaping window 126 is used to shape the light emitted by the light-emitting body 120 into a rectangular light spot having the same shape and size as the rectangular hole formed in the support light-shielding plate 106. An image sensor 111 is disposed on the side of the spectroscope 112 away from the transparent measurement chamber 101. The image sensor 111 is used to receive the light emitted by the light-emitting body 120. The light received by the image sensor 111 is the light emitted by the light-emitting body 120 that is split into multiple parallel light spots by the spectroscope 112. A concave lens 125 is fixedly installed on one side of the inner wall of the light-shielding housing 118 located in the transparent measurement chamber 101. A convex lens frame 123 is engaged between the opposite surface of the concave lens 125 and the light-emitting body 120. The convex lens frame 123 is slidably engaged with the inner wall of the light-shielding housing 118, and a convex lens 124 is fixedly installed on the convex lens frame 123. The convex lens 124 and the concave lens 125 are used to adjust the light emitted by the light-emitting body 120 into a parallel light beam. The convex lens frame 123 is slidably installed on a guiding slide rod 122, and the guiding slide rod 122 is fixed on the light-shielding housing 118 and the light-emitting body support 117. An adjusting lead screw 119 is also rotatably engaged on the light-emitting body support 117. The adjusting lead screw 119 is in threaded driving engagement with the convex lens frame 123 and is used to adjust the distance between the convex lens 124 and the concave lens 125. A locking screw 121 is also threadedly installed on the light-emitting body support 117, and the locking screw 121 is used to fix the adjusting lead screw 119 to the light-emitting body support 117. An image sensor mounting frame 107 is fixedly installed on the support light-shielding plate 106. The image sensor mounting frame 107 is used to enclose the spectroscope 112. The image sensor 111 is fixedly installed on the image sensor mounting frame 107. An image sensor heat conducting plate 108 is fixedly installed on the image sensor mounting frame 107. A heat conducting silicone grease is provided between the image sensor heat conducting plate 108 and the image sensor 111. Two symmetrically arranged image sensor heat sinks 109 are fixedly installed on the side surface of the transparent measurement chamber 101. Heat conduction cooperation is achieved between the two image sensor heat sinks 109 and the image sensor heat conducting plate 108 through an image sensor heat conduction tube 110.A light-emitting body evaporation chamber 114 is disposed between two image sensor heat sinks 109. The light-emitting body evaporation chamber 114 is fixedly fitted with the transparent measurement chamber 101. A light-emitting body condensation heat sink 113 is fixedly and sealed on the light-emitting body evaporation chamber 114. A light-emitting body heat conducting plate 116 is fixedly attached to the light-emitting body support 117. The light-emitting body heat conducting plate 116 and the interior of the light-emitting body evaporation chamber 114 are fixedly communicated through an evaporation heat conducting tube 115. Two conversion joints 102 are fixedly communicated and installed at both ends of the transparent measurement chamber 101 in a manner convenient for disassembly. Two symmetrically arranged protective shells 103 are sleeved outside the transparent measurement chamber 101. An exhaust port 105 is opened on one of the protective shells 103, and an intake fan 104 is fixedly provided on the other protective shell 103. The intake fan 104, the exhaust port 105, the image sensor heat sink 109, and the light-emitting body condensation heat sink 113 are aligned. The inner wall of the transparent measurement chamber 101 is fixedly installed with an inner accessory transparent tube 127 in a manner convenient for disassembly. The inner accessory transparent tube 127 and the transparent measurement chamber 101 are fixedly fitted through a stud 128. The outer surface of the inner accessory transparent tube 127 and the inner wall of the transparent measurement chamber 101 are in sliding seal fit. The corresponding position of the inner wall of the inner accessory transparent tube 127 and the spectroscope 112 is arranged in a flat surface, and the flat surface is in a stepped shape to prevent light from shifting after passing through the inner accessory transparent tube 127. The spectroscope 112 is composed of multiple parallel light-impermeable aluminum foil plates, so that multiple equidistant and uniformly distributed gaps are formed on the spectroscope 112. A vibration column 129 is fixedly installed at the end of the inner wall of the transparent measurement chamber 101. The vibration column 129 is located in the flow direction of the fluid inside the transparent measurement chamber 101 and is used to drive the fluid to vibrate, so that the fluid generates bubbles through the cavitation effect, and the generated bubbles pass between the light shaping window 126 and the spectroscope 112.

[0024] The working principle of a laminar flowmeter disclosed by the present invention is as follows: Whether to install the adapter 102 is selected according to the type of the pipeline to be measured, and an adapter 102 with a suitable size is selected for installation. It should be noted that the vibrating column 129 is positioned in the fluid flow direction, so that the fluid first passes through the vibrating column 129 and then flows into the transparent measurement chamber 101. During measurement, first, the light emitter 120 and the image sensor 111 are activated. The light emitted by the light emitter 120 sequentially passes through the convex lens 124, the concave lens 125, the transparent measurement chamber 101, the fluid to be measured (if the inner fitting transparent tube 127 is installed, it will also pass through the inner fitting transparent tube 127), the transparent measurement chamber 101, the beam splitter 112, and then is received by the image sensor 111. When the fluid is in a laminar flow state inside the transparent measurement chamber 101, the flow velocity at the center is higher than that on the surface of the transparent measurement chamber 101, and it has a parabolic profile and is also symmetric about the central axis of the transparent measurement chamber 101. Therefore, only by measuring the velocity of half of the fluid can the velocities at all positions be known, and then the flow rate can be calculated by combining with the cross-sectional area. Specifically, the piezoelectric ceramics inside the vibrating column 129 are activated (piezoelectric ceramics are provided inside the vibrating column 129 to generate vibration). The vibration of the vibrating column 129 will drive the nearby fluid to vibrate, and the fluid vibration will generate bubbles through the cavitation effect (the amplitude needs to exceed the cavitation threshold of the fluid (related to fluid properties such as surface tension, pressure, and dissolved gas content)). In laminar flow, small bubbles (with diameters much smaller than the pipeline size) are affected by the Stokes drag force, and their velocities are the same as those of the fluid. Therefore, the flow velocity of the fluid can be judged by detecting the movement velocity of the bubbles. When the bubbles move between the light emitter 120 and the image sensor 111, they will change the light propagation path, that is, a shadow will be formed on the image sensor 111. By detecting the movement velocity of the shadow frame by frame on the image sensor 111 (within the range where the image sensor 111 receives light, the time for the shadow to move, and the velocity is judged by time and distance), the flow velocity of the fluid can be judged. A plurality of parallel opaque aluminum foil plates provided on the beam splitter 112 are arrayed in the direction perpendicular to the fluid flow direction, and the light from the light emitter 120 is divided into multiple portions and received by the image sensor 111, that is, the movement velocities of bubbles in each layer are measured, that is, the movement velocities of the fluid in each layer.Before use, loosen the locking screw 121 with a wrench, and then rotate the adjusting screw rod 119 with a wrench. The rotation of the adjusting screw rod 119 will drive the convex lens 124 on the convex lens frame 123 to move along the axial direction of the adjusting screw rod 119. At this time, the distance between the concave lens 125 and the convex lens 124 will change, so as to adjust the light intensity and range of the light emitted by the light-emitting body 120 onto the image sensor 111. For example, the light emitted by the concave lens 125 is completely parallel, and at this time, the area of the light completely overlaps with the image sensor 111. If the light emitted from the concave lens 125 diverges outward, the light intensity received by the image sensor 111 will decrease. On the contrary, if the light emitted from the concave lens 125 contracts inward, the light intensity received by the image sensor 111 will increase, but the area projected onto the image sensor 111 will decrease, that is, the moving distance of the bubbles that can be measured will be shortened, and the accuracy will decrease accordingly (selected according to the specific fluid transparency). After the adjustment is completed, tighten the locking screw 121 again to fix the adjusting screw rod 119.

[0025] Heat will be generated when the light-emitting body 120 and the image sensor 111 are working. The heat of the light-emitting body 120 will be transferred to the light-emitting body condensation heat sink 113 through the light-emitting body bracket 117, the light-emitting body heat conducting plate 116, the evaporation heat conducting tube 115, and the light-emitting body evaporation chamber 114. The heat of the image sensor 111 will be transferred to the image sensor heat sink 109 through the image sensor heat conducting plate 108 and the image sensor heat conducting tube 110. The light-emitting body heat conducting plate 116, the evaporation heat conducting tube 115, and the light-emitting body evaporation chamber 114 are internally provided with a coolant to facilitate the absorption and dissipation of heat. Moreover, the light-emitting body heat conducting plate 116, the evaporation heat conducting tube 115, the light-emitting body evaporation chamber 114, and the light-emitting body condensation heat sink 113 are in a negative pressure environment to facilitate the evaporation and condensation of the coolant, so as to improve the heat dissipation efficiency. By starting the intake fan 104, the intake fan 104 drives the external cold air through the light-emitting body condensation heat sink 113 and the image sensor heat sink 109, thereby dissipating heat from the image sensor heat sink 109 and the light-emitting body condensation heat sink 113. The heat-dissipated gas will be discharged through the exhaust port 105.

Claims

1. A laminar flow meter, characterized in that: On both sides of the outer surface of the transparent measurement chamber (101), a support light-shielding plate (106) and a light-shielding housing (118) are fixedly installed respectively. A rectangular hole is formed in the support light-shielding plate (106), and a spectroscope (112) fixedly fitted with the outer surface of the transparent measurement chamber (101) is arranged in the rectangular hole. On one side of the inner wall of the light-shielding housing (118) facing the transparent measurement chamber (101), a light shaping window (126) is provided. On the side of the light-shielding housing (118) far from the transparent measurement chamber (101), a light-emitting body support (117) is fixed, and a light-emitting body (120) is fixedly installed on the light-emitting body support (117). The light shaping window (126) is used to shape the light emitted by the light-emitting body (120) into a rectangular light spot with the same shape and size as the rectangular hole formed in the support light-shielding plate (106). On the side of the spectroscope (112) far from the transparent measurement chamber (101), an image sensor (111) is provided. The image sensor (111) is used to receive the light emitted by the light-emitting body (120). The light received by the image sensor (111) is the light emitted by the light-emitting body (120) that is split into multiple parallel light spots by the spectroscope (112).

2. The laminar flowmeter according to claim 1, wherein: On one side of the inner wall of the light-shielding housing (118) located in the transparent measurement chamber (101), a concave lens (125) is fixedly installed. A convex lens frame (123) is arranged between the opposite surfaces of the concave lens (125) and the light-emitting body (120). The convex lens frame (123) is slidably fitted with the inner wall of the light-shielding housing (118), and a convex lens (124) is fixedly installed on the convex lens frame (123).

3. The laminar flowmeter according to claim 2, wherein: The convex lens (124) and the concave lens (125) are used to adjust the light emitted by the light-emitting body (120) into a parallel light beam. The convex lens frame (123) is slidably installed on a guiding slide rod (122). The guiding slide rod (122) is fixed on the light-shielding housing (118) and the light-emitting body support (117). An adjusting lead screw (119) is also rotatably arranged on the light-emitting body support (117). The adjusting lead screw (119) is in threaded transmission cooperation with the convex lens frame (123) and is used to adjust the distance between the convex lens (124) and the concave lens (125). A locking screw (121) is also threadedly installed on the light-emitting body support (117). The locking screw (121) is used to fix the adjusting lead screw (119) and the light-emitting body support (117).

4. The laminar flowmeter according to claim 3, characterized in that: An image sensor mounting frame (107) is fixedly installed on the support light shield (106). The image sensor mounting frame (107) is used to wrap the optical splitter (112). An image sensor (111) is fixedly installed on the image sensor mounting frame (107). An image sensor heat conducting plate (108) is fixedly installed on the image sensor mounting frame (107). A heat conducting silicone grease is provided between the image sensor heat conducting plate (108) and the image sensor (111). Two symmetrically arranged image sensor heat sinks (109) are fixedly installed on the side of the transparent measurement chamber (101). The two image sensor heat sinks (109) are thermally conducted and cooperated with the image sensor heat conducting plate (108) through an image sensor temperature conducting pipe (110).

5. The laminar flowmeter according to claim 4, wherein: A light emitter evaporation chamber (114) is arranged between the two image sensor heat sinks (109). The light emitter evaporation chamber (114) is fixedly cooperated with the transparent measurement chamber (101). A light emitter condensation heat sink (113) is fixedly and sealedly installed on the light emitter evaporation chamber (114). A light emitter heat conducting plate (116) is fixedly attached to the light emitter support (117). The light emitter heat conducting plate (116) is fixedly communicated with the inside of the light emitter evaporation chamber (114) through an evaporation temperature conducting pipe (115).

6. The laminar flowmeter according to claim 5, wherein: Two adapter joints (102) are fixedly communicated and installed at both ends of the transparent measurement chamber (101) in a manner that is convenient for disassembly. Two symmetrically arranged protective shells (103) are sleeved outside the transparent measurement chamber (101). An exhaust port (105) is opened on one of the protective shells (103). An intake fan (104) is fixedly arranged on the other protective shell (103). The intake fan (104), the exhaust port (105), the image sensor heat sinks (109), and the light emitter condensation heat sink (113) are arranged in alignment.

7. A laminar flow meter according to claim 6, characterized in that: An inner accessory transparent tube (127) is fixedly installed on the inner wall of the transparent measurement chamber (101) in a manner that is convenient for disassembly. The inner accessory transparent tube (127) is fixedly cooperated with the transparent measurement chamber (101) through a stud (128). The outer surface of the inner accessory transparent tube (127) is in sliding seal cooperation with the inner wall of the transparent measurement chamber (101).

8. A laminar flowmeter according to claim 7, characterized in that: The inner wall of the inner accessory transparent tube (127) and the corresponding position of the optical splitter (112) are arranged in a flat surface, and the flat surface is in a stepped shape to prevent the light from shifting after passing through the inner accessory transparent tube (127). The optical splitter (112) is composed of multiple parallel opaque aluminum foil plates, so that multiple equidistant and evenly distributed gaps are formed on the optical splitter (112).

9. A laminar flowmeter according to claim 8, wherein: A vibration column (129) is fixedly installed at the end of the inner wall of the transparent measurement chamber (101). The vibration column (129) is located in the flow direction of the fluid inside the transparent measurement chamber (101) and is used to drive the fluid to vibrate, so that the fluid generates bubbles through the cavitation effect, and the generated bubbles pass between the light shaping window (126) and the optical splitter (112).

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