Flow-adjustable gas circulation output device and flow verification system
By using a variable frequency motor to drive the impeller and a reflux bypass design, combined with a rotary valve plate and a temperature regulator, the problem of precise control of the gas circulation output device under low flow conditions was solved, achieving improved flow stability and accuracy, and reducing energy consumption.
Patent Information
- Application Number
- CN202511231094.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-30
- Publication Date
- 2025-11-21
AI Technical Summary
Existing gas circulation output devices are difficult to control precisely at low flow rates, which can easily lead to surge and unstable flow, as well as increased load on the fan motor and higher energy consumption.
The impeller is driven by a variable frequency motor, and combined with a reflux bypass and reflux regulating valve, the gas flow rate is controlled by adjusting the flow area ratio of the circulation valve port and the bypass valve port; the valve port size is precisely adjusted by a rotary valve plate and valve plate motor, and the gas temperature is kept stable by a temperature regulator.
It achieves stable and precise control of gas flow under low flow conditions, reduces the load on the fan motor, reduces energy consumption, and improves the accuracy of flow regulation and the stability of the system.
Smart Images
Figure CN120992000A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of flow calibration devices, and more particularly to a flow-adjustable gas circulation output device. Furthermore, this application also relates to a flow calibration system. Background Technology
[0002] A flow meter is a measuring instrument used to indicate the flow rate of a fluid. To ensure the accuracy of the flow meter's readings, it is usually necessary to perform periodic verification and calibration during use.
[0003] When calibrating a flow meter, the flow meter to be calibrated and a standard flow meter are usually connected in series in the test fluid pipeline of the flow calibration system. By controlling the flow rate of the fluid in the test fluid pipeline, the measured values of the two flow meters at different flow rates are compared to determine the error of the flow meter to be calibrated.
[0004] When calibrating a gas flow meter, the gas flow rate in the test flow pipeline is typically provided by a gas circulation output device with adjustable output flow. Existing gas circulation output devices usually control the drive frequency of the fan motor via a frequency converter, thereby controlling the fan motor speed and thus the output gas flow rate. However, the drive frequency of the fan motor usually needs to be maintained between 5Hz and 50Hz. Once the drive frequency of the fan motor drops below 5Hz, the adjustment of the fan motor speed becomes nonlinear, easily causing surge and making it difficult to control the gas output flow rate accurately when the output flow rate is low.
[0005] To stably output a lower flow rate, some gas circulation output devices install flow regulating valves on the gas output pipeline, reducing the flow rate of the output gas by decreasing the flow area of the output pipeline. However, the significant reduction in the flow area of the output pipeline will cause changes in the output gas pressure, which not only affects the accuracy of the output gas flow control, but also increases the operating load of the fan motor, causing the output gas temperature to rise and increasing the energy consumption of the fan motor and the associated temperature regulator. Summary of the Invention
[0006] To improve the output flow control accuracy at smaller output flow rates, this application provides an adjustable gas circulation output device and a flow calibration system.
[0007] The adjustable flow gas circulation output device provided in this application adopts the following technical solution: An adjustable flow gas circulation output device includes a variable frequency motor, a housing, an impeller, a reflux regulating valve, a reflux bypass, and a circulating gas output port. The variable frequency motor is driven and connected to the impeller, which is disposed within the housing. A fan outlet is provided on the housing. The reflux regulating valve is disposed on the housing and includes a circulation valve port and a bypass valve port. The reflux regulating valve can adjust the flow area ratio of the circulation valve port and the bypass valve port. The impeller can drive gas to flow through the circulation valve port and the bypass valve port to the fan outlet. The circulating gas output port is connected to the fan outlet. One end of the reflux bypass is connected to the connection passage between the circulating gas output port and the fan outlet, and the other end is connected to the bypass valve port. The circulation valve port is connected to the output gas circulation loop.
[0008] By adopting the above technical solution, and utilizing a variable frequency motor connected to the impeller drive, the motor speed can be controlled by adjusting the starting frequency of the variable frequency motor when the gas output flow rate is large, thereby controlling the flow rate of the impeller-driven gas. By using a recirculation bypass located between the fan outlet and the bypass valve, a portion of the gas flow generated by the impeller drive can be returned to the bypass valve. This allows for a smaller output flow rate even when the impeller-driven gas flow rate is large. The output flow rate is further controlled by adjusting the flow area of the circulation valve and the bypass valve through a recirculation regulating valve. This results in a smaller gas output flow rate even when the variable frequency motor is at a relatively high fixed drive frequency, achieving both stable and precise control of this smaller gas output flow rate.
[0009] In one specific implementation, the reflux regulating valve includes a regulating valve flange, a rotary valve plate, and a valve plate motor. The regulating valve flange is provided with a flange circulation hole and a flange bypass hole. The rotary valve plate is provided with a valve plate circulation hole and a valve plate bypass hole. The rotary valve plate is rotatably mounted on the regulating valve flange. The valve plate motor is fixed on the regulating valve flange on the side opposite to the rotary valve plate, and a drive shaft passes through the regulating valve flange and is driven to the rotary valve plate to drive the rotary valve plate to rotate. The valve plate circulation hole overlaps with the flange circulation hole to form the circulation valve port, and the valve plate bypass hole overlaps with the flange bypass hole to form the bypass valve port flow area.
[0010] By adopting the above technical solution, a rotary valve plate is mounted on the regulating valve flange, and a valve plate circulation hole and a valve plate bypass hole are provided on the rotary valve plate. The flange circulation hole and flange bypass hole are provided on the regulating valve flange, which facilitates the control of the rotation state of the rotary valve plate by the valve plate motor. This allows control of the size of the circulation valve port formed by the overlap of the valve plate circulation hole and the flange circulation hole, and the size of the bypass valve port formed by the overlap of the valve plate bypass hole and the flange bypass hole. This controls the flow rate ratio of the gas returning through the circulation valve port and the bypass valve port, thereby precisely controlling the flow rate of the gas output through the circulating gas outlet without changing the speed of the variable frequency motor.
[0011] In one specific implementation scheme, both the flange circulation hole and the flange bypass hole are circular holes. The diameter of the flange circulation hole is larger than the diameter of the flange bypass hole. The valve plate circulation hole is a circular hole with the same diameter as the flange circulation hole. The valve plate bypass hole is an oblong hole with two sides centered on the rotation axis of the rotating valve plate, and the distance between the two sides is equal to the diameter of the flange bypass hole. The relative positions of the valve plate circulation hole and the valve plate bypass hole are configured such that when the rotating valve plate rotates to the point where the area of the circulation valve port is equal to the area of the valve plate bypass hole, the valve plate bypass hole and the flange bypass hole begin to overlap. When the circulation valve port is closed, the flange bypass hole is still in a state of complete overlap with the valve plate bypass hole.
[0012] By adopting the above technical solution, using a waist-shaped valve plate bypass hole with the rotation axis of the rotating valve plate as the center and the distance between the two sides equal to the diameter of the flange bypass hole, the area of the bypass valve port can remain constant as the area of the circulating valve port gradually decreases, improving the uniformity of the flow area ratio adjustment between the circulating valve port and the bypass valve port. When the rotating valve plate rotates to the point where the area of the circulating valve port equals the area of the valve plate bypass hole, the valve plate bypass hole and the flange bypass hole begin to overlap. Furthermore, when the circulating valve port is closed, the flange bypass hole is still in a state of complete overlap with the valve plate bypass hole. This ensures that the total flow area of the impeller-driven circulating gas is not less than the area of the flange bypass hole, preventing excessive load on the variable frequency motor due to an insufficient circulating gas flow area, which would increase the energy consumption of the variable frequency motor and cause an unnecessary rise in gas temperature.
[0013] In one specific implementation scheme, when the rotary valve plate rotates to the point where the distance between the center of the valve plate circulation hole and the center of the flange circulation hole is equal to the diameter of the valve plate circulation hole, a pointed groove protruding towards the center of the flange circulation hole is provided on the side of the valve plate circulation hole adjacent to the flange circulation hole. Before the pointed groove is separated from the flange circulation hole, the flange bypass hole is still in a state of complete overlap with the valve plate bypass hole.
[0014] By adopting the above technical solution, the pointed groove protruding from the edge of the valve plate circulation hole towards the center of the flange circulation hole can make the circulation valve port form a relatively slow process approaching zero before it is completely closed, thereby effectively improving the flow rate regulation accuracy of the gas through the circulation valve port under a smaller flow area, that is, the flow rate regulation accuracy of the small flow rate of gas output through the circulation gas outlet.
[0015] In one specific implementation scheme, valve plate drive teeth are provided on the outer peripheral surface of the rotary valve plate, and motor gears are provided on the output shaft of the valve plate motor, the motor gears meshing with the valve plate drive teeth.
[0016] By adopting the above technical solution, and utilizing the meshing of the motor gear on the output shaft of the valve plate motor with the valve plate drive teeth on the outer circumference of the rotary valve plate, a large reduction ratio of the valve plate motor to the rotary valve plate can be formed, thereby improving the control accuracy of the rotation angle of the rotary valve plate.
[0017] In one specific implementation, the flow-adjustable gas circulation output device of this application further includes a controller, an angular displacement sensor disposed on the regulating valve flange opposite to the rotary valve plate, the valve plate motor is a CNC drive motor, and both the angular displacement sensor and the valve plate motor are connected to the controller.
[0018] By adopting the above technical solution, using an angular displacement sensor installed on the flange of the regulating valve opposite to the rotary valve plate, the rotation angle of the rotary valve plate can be accurately measured, and the actual rotation angle of the rotary valve plate can be transmitted to the controller. The rotation angle of the rotary valve plate is then adjusted based on feedback, thereby improving the accuracy of adjusting the rotation angle of the rotary valve plate.
[0019] In one specific implementation, a temperature regulator is provided between the fan outlet and the circulating gas outlet, and the recirculation bypass is connected between the temperature regulator and the circulating gas outlet.
[0020] By adopting the above technical solution, the temperature regulator installed between the fan outlet and the circulating gas outlet can be used to adjust the temperature of the gas output through the fan outlet, so that the circulating gas output through the circulating gas outlet maintains a stable temperature and ensures that the circulating gas temperature meets the requirements for flow meter calibration.
[0021] In one specific implementation, the reflux regulating valve and the temperature regulator are respectively disposed at opposite ends of the housing, the variable frequency motor is disposed inside the housing, the impeller is fixed on the output shaft of the variable frequency motor, and the fan outlet is disposed on the end face of the housing connected to the temperature regulator.
[0022] By adopting the above technical solution, and utilizing the variable frequency motor installed inside the housing, the reflux regulating valve and the temperature regulator can be respectively installed on opposite ends of the housing. This allows the impeller-driven airflow to directly enter the temperature regulator through the fan outlet at the end of the housing, making the connection between the housing and the temperature regulator more compact and improving the structural stability of the flow-adjustable gas circulation output device of this application.
[0023] In one specific implementation, the reflux regulating valve and the temperature regulator are respectively located at opposite ends of the housing, and the variable frequency motor is located on the reflux regulating valve; or the variable frequency motor and the reflux regulating valve are respectively located at opposite ends of the housing, and the fan outlet is located on the side wall of the housing. The variable frequency motor is disposed outside the housing. The output shaft of the variable frequency motor is positioned opposite to the rotating shaft of the impeller. A magnetic connector is provided between the output shaft of the variable frequency motor and the rotating shaft of the impeller. The magnetic connector includes a driving half-coupling and a driven half-coupling. The rotating shaft of the impeller extends through the reflux regulating valve or housing to the outside of the housing. The driven half-coupling is fixed to the rotating shaft of the impeller. An isolation cover is provided on the outside of the reflux regulating valve or housing. The isolation cover is sealed to the reflux regulating valve or housing, so that the driven half-coupling is located inside the isolation cover. The driving half-coupling is cylindrical. One end of the driving half-coupling is fixed to the output shaft of the variable frequency motor, and the other end is sleeved on the outside of the isolation cover. The driving half-coupling and the driven half-coupling are magnetically connected.
[0024] By adopting the above technical solution, and utilizing the placement of the variable frequency motor at the outer end of the housing, direct contact between the circulating gas and the motor can be avoided, preventing the absorption of heat generated by the motor's operation and reducing the workload of the temperature regulator. Furthermore, by using a magnetic connector between the output shaft of the variable frequency motor and the impeller shaft, a non-contact magnetic connection can be formed between the motor and the impeller. This allows the use of an isolation cover to ensure a seal between the inside and outside of the housing at the connection point, guaranteeing the accuracy of the detected gas output flow rate.
[0025] The flow calibration system provided in this application uses the flow-adjustable gas circulation output device provided in this application and also has the above-mentioned advantages.
[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. By setting a reflux bypass between the outlet and inlet ends of the impeller and a reflux regulating valve at the inlet end of the impeller, the output gas flow rate can be adjusted by regulating the speed of the variable frequency motor under high flow output conditions. When the speed of the variable frequency motor reaches 5Hz, the speed of the variable frequency motor is no longer reduced. Instead, the output gas flow rate is adjusted by regulating the proportion of output gas returning through the reflux bypass through the reflux regulating valve. This greatly expands the output flow range and improves the stability and flow regulation accuracy under low flow conditions.
[0027] 2. By using the circular valve plate circulation hole and the oblong valve plate bypass hole on the rotary valve plate, the size of the circulation valve port and the return valve port can be precisely adjusted by controlling the rotation angle of the rotary valve plate. This allows for precise control of the ratio of gas output from the impeller through the circulation pipeline to gas returned through the return pipeline, thereby significantly reducing the gas flow rate output through the circulation pipeline and effectively improving the flow rate regulation accuracy of the circulating gas under low flow conditions. Furthermore, it ensures that the return valve port area is kept at its maximum when the circulation valve port area is small, resulting in a larger minimum value for the gas flow rate output from the impeller and reducing the workload of the variable frequency motor.
[0028] 3. By setting a pointed groove protruding towards the center of the flange circulation hole on one side of the valve plate circulation hole, a longer transition process towards zero is achieved when the circulation valve port area formed by the overlap of the valve plate circulation hole and the flange circulation hole is close to zero. This allows the circulation valve port area to change slowly towards zero while the return valve port area remains unchanged, effectively expanding the adjustable range of the ratio of the return valve port area to the circulation valve port area, and improving the low flow rate adjustment range and adjustment accuracy of the circulating gas.
[0029] 4. By installing a temperature regulator at the fan outlet and placing the variable frequency motor outside the casing, the heating effect of the variable frequency motor on the gas can be reduced, the workload of the temperature regulator can be reduced, and the risk of corrosion and insulation degradation caused by the variable frequency motor working in the casing environment for a long time can be reduced. Attached Figure Description
[0030] Figure 1 This is a schematic diagram of one embodiment of the flow-adjustable gas circulation output device of this application.
[0031] Figure 2 This is a cross-sectional schematic diagram of one embodiment of the flow-adjustable gas circulation output device of this application.
[0032] Figure 3 This is an exploded view of the reflux regulating valve in one embodiment of the flow-adjustable gas circulation output device of this application.
[0033] Figure 4This is a schematic diagram of a rotating state of the rotary valve plate of the reflux regulating valve in one embodiment of the flow-adjustable gas circulation output device of this application.
[0034] Figure 5 This is a schematic diagram of another rotation state of the rotary valve plate of the reflux regulating valve in one embodiment of the flow-adjustable gas circulation output device of this application.
[0035] Figure 6 This is a schematic diagram of another embodiment of the flow-adjustable gas circulation output device of this application.
[0036] Figure 7 yes Figure 6 Enlarged view of part A in the middle.
[0037] Figure 8 This is a schematic diagram of another embodiment of the flow-adjustable gas circulation output device of this application.
[0038] Figure 9 yes Figure 8 Enlarged view of part B in the middle section.
[0039] Explanation of reference numerals in the attached figures: 1. Variable frequency motor; 2. Housing; 21. Fan outlet; 22. Isolation cover; 3. Impeller; 4. Return flow regulating valve; 401. Circulation valve port; 402. Bypass valve port; 41. Regulating valve flange; 411. Flange circulation hole; 412. Flange bypass hole; 413. Angular displacement sensor; 42. Rotary valve plate; 421. Valve plate circulation hole; 4211. Spiral groove; 422. Valve plate bypass hole; 423. Valve plate drive gear; 43. Valve plate motor; 431. Motor gear; 44. Circulating air inlet; 45. Bypass air inlet; 46. Regulating valve outlet; 47. Valve plate cover; 471. Cover plate circulation hole; 472. Cover plate bypass hole; 5. Return flow bypass; 6. Circulating gas outlet; 7. Temperature regulator; 8. Magnetic connector; 81. Active half coupling; 82. Driven half coupling. Detailed Implementation
[0040] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.
[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0042] One embodiment of the flow-adjustable gas circulation output device of this application, such as Figures 1 to 5 As shown, the system includes a variable frequency motor 1, a housing 2, an impeller 3, a reflux regulating valve 4, a reflux bypass 5, and a circulating gas outlet 6. The variable frequency motor 1 is driven by the impeller 3. Typically, the impeller 3 is fixed to the output shaft of the variable frequency motor 1, but it can also be driven by other suitable methods. The impeller 3 is housed inside the housing 2. The variable frequency motor 1 can be housed inside the housing 2 or outside the housing. The impeller 3 rotates under the drive of the variable frequency motor, thereby driving the gas flow within the housing 2.
[0043] A fan outlet 21 is provided on the housing 2. The fan outlet 21 can be located on the side wall of the housing 2 opposite to the impeller 3, or it can be located on the end face of the housing 2. A recirculation regulating valve 4 is located on the housing 2. A circulating air inlet 44 and a bypass air inlet 45 are provided on one side of the recirculation regulating valve 4, and a regulating valve outlet 46 is provided on the other side. The recirculation regulating valve 4 is provided with a circulating valve port 401 and a bypass valve port 402. The circulating valve port 401 is located between the circulating air inlet 44 and the regulating valve outlet 46, and the bypass valve port 402 is located between the bypass air inlet 45 and the regulating valve outlet 46. The regulating valve outlet 46 is located at the air inlet end of the impeller 3 inside the housing 2. The circulating gas outlet 6 is connected to the fan outlet 21 via a connecting pipe. One end of the return bypass 5 is connected to the connecting pipe between the circulating gas outlet 6 and the fan outlet 21, and the other end is connected to the bypass air inlet 45. The circulating gas outlet 6 and the circulating air inlet 44 are respectively connected to the circulating air inlet and circulating air outlet of the external gas-using equipment via connecting pipes.
[0044] Driven by the variable frequency motor 1, the impeller 3 rotates, and the driving gas is output from the fan outlet 21. The gas output from the fan outlet 21 is then output through the circulating gas outlet 6 for use by external equipment. The circulating gas used by the external equipment returns to the circulating air inlet 44 on the return regulating valve 4, and then flows back to the air inlet of the impeller 3 through the circulating valve port 401 and the regulating valve outlet 46. Part of the gas output from the fan outlet 21 can flow back to the bypass air inlet 45 through the return bypass 5, and then flow back to the air inlet of the impeller 3 through the bypass valve port 402 and the regulating valve outlet 46, participating in the airflow circulation driven by the impeller 3. The return regulating valve 4 can adjust the flow area ratio of the circulating valve port 401 and the bypass valve port 402, thereby adjusting the flow rate ratio of the circulating gas flowing through the circulating valve port 401 to the bypass gas flowing through the bypass valve port 402.
[0045] The adjustable gas circulation output device of this application can significantly adjust the flow rate of the circulating gas output through the circulating gas output port 6 according to the needs of external equipment: when the required circulating gas flow rate is large, such as 800-8000 m³ / h. 3 When the flow rate is within the range of / h, the circulating gas flow rate can be adjusted by controlling the rotation speed of the variable frequency motor 1. At this time, the return regulating valve 4 is adjusted so that the circulation valve port 401 is fully open and the bypass valve port 402 is closed. All the gas driven by the impeller 3 is output to the external equipment through the circulating gas output port 6. The circulating gas returning from the external equipment flows back to the air inlet of the impeller 3 through the circulation valve port 401 and the regulating valve outlet 46, forming a cycle. By adjusting the speed of the variable frequency motor 1 within the range of 5-50Hz, the circulating gas flow rate can be adjusted to 800-8000m³ / h. 3 Adjustment within the range of / h.
[0046] When the required output circulating gas flow rate is less than 800 m³ / h 3When the flow rate is / h, if the flow rate of the circulating gas is adjusted only by adjusting the speed of the variable frequency motor 1, the speed of the variable frequency motor 1 will be lower than 5Hz. This will cause the gas flow rate output by the impeller 3 to no longer change linearly with the speed of the variable frequency motor 1, and the linkage between the impeller 3 and the variable frequency motor 1 will surge, resulting in unstable circulating gas and inability to make precise adjustment. At this time, the speed of the variable frequency motor 1 is maintained at 5Hz, and the flow rate of the circulating gas is adjusted by the return regulating valve 4. Specifically, the flow area of the circulation valve port 401 is gradually reduced, and the flow area of the bypass valve port 402 is gradually reduced, so that part of the gas output from the fan outlet 21 flows back to the air inlet of the impeller 3 through the return bypass 5, the bypass air inlet 45, the bypass valve port 402, and the regulating valve outlet 46; the other part of the gas is output through the circulating gas outlet 6 and flows back to the air inlet of the impeller 3 through the circulating air inlet 44, the circulation valve port 401, and the regulating valve outlet 46. By adjusting the flow area ratio of the bypass valve port 402 to the circulation valve port 401, the flow rate ratio of the bypass gas returning through the fan outlet 21 via the return bypass 5 and the bypass valve port 402 can be adjusted to that of the circulating gas output through the circulating gas outlet 6 and the circulating valve port 401. This further reduces the flow rate of the circulating gas output through the circulating gas outlet 6 without reducing the speed of the variable frequency motor 1 or the total gas flow driven by the impeller 3, while maintaining the accuracy of circulating gas flow rate adjustment at lower flow rates. For example, when the flow area ratio of the bypass valve port 402 to the circulation valve port 401 is 1:1, the circulating gas flow rate can be adjusted to 400 m³ / h. 3 / h; When the flow area ratio of bypass valve port 402 to circulation valve port 401 is 9:1, the circulating gas flow rate can be adjusted to 40 m3 / h; When the flow area ratio of bypass valve port 402 to circulation valve port 401 is 99:1, the circulating gas flow rate can be adjusted to 4 m 3 / h.
[0047] In some embodiments of the flow-adjustable gas circulation output device of this application, such as Figure 3 As shown, the reflux regulating valve 4 includes a regulating valve flange 41, a rotary valve plate 42, and a valve plate motor 43. The regulating valve flange 41 is provided with a flange circulation hole 411 and a flange bypass hole 412, and the rotary valve plate 42 is provided with a valve plate circulation hole 421 and a valve plate bypass hole 422. The rotary valve plate 42 is rotatably disposed on one side of the regulating valve flange 41.
[0048] A valve plate cover 47 can also be provided on one side of the regulating valve flange 41. The valve plate cover 47 has a cover plate circulation hole 471 and a cover plate bypass hole 472. The valve plate cover 47 is fixed to one side of the regulating valve flange 41, such that the cover plate circulation hole 471 corresponds to the flange circulation hole 411, and the cover plate bypass hole 472 corresponds to the flange bypass hole 412. A valve plate mounting space is formed between the valve plate cover 47 and the regulating valve flange 41. The rotating valve plate 42 is installed in the valve plate mounting space and can rotate within the valve plate mounting space.
[0049] A valve plate sealing ring is provided on the side of the regulating valve flange 41 adjacent to the rotary valve plate 42, corresponding to the periphery of the rotary valve plate 42. A circulation hole sealing ring and a bypass hole sealing ring are respectively provided around the flange circulation hole 411 and the flange bypass hole 412 to ensure the sealing of the part in contact with the regulating valve flange 41 during the rotation of the rotary valve plate 42.
[0050] The valve plate motor 43 is fixed on the side of the regulating valve flange 41 opposite to the rotary valve plate 42, and the output shaft of the valve plate motor 43 passes through the regulating valve flange 41 and is driven by the rotary valve plate 42. Normally, the output shaft of the valve plate motor 43 passes through the regulating valve flange 41 from the outside of the valve plate sealing ring, ensuring that the gas flowing from the return regulating valve 4 does not leak to the position where the output shaft of the valve plate motor 43 passes through.
[0051] The valve plate motor 43 can drive the rotary valve plate 42 to rotate, thereby changing the relative positions of the valve plate circulation hole 421 and valve plate bypass hole 422 with the flange circulation hole 411 and flange bypass hole 412. This allows the valve plate circulation hole 421 and flange circulation hole 411 to form a circulation valve port 401 in a set rotation state of the rotary valve plate 42, and the flow area of the circulation valve port 401 formed by the overlap of the valve plate circulation hole 421 and flange circulation hole 411 can be controlled. At the same time, the valve plate bypass hole 422 and flange bypass hole 412 can form a bypass valve port 402 in another set rotation state of the rotary valve plate 42, and the flow area of the bypass valve port 402 formed by the overlap of the valve plate bypass hole 422 and flange bypass hole 412 can be controlled. By changing the flow area of the circulation valve port 401 and the bypass valve port 402 under different rotation states of the rotary valve plate 42, the flow area ratio of the circulation valve port 401 and the bypass valve port 402 is adjusted. That is, the ratio of the airflow driven by the impeller 3 to be output through the circulating gas output port 6 and returned through the return bypass 5 is adjusted. Thus, the flow rate of the circulating gas output through the circulating gas output port 6 is adjusted while the airflow driven by the impeller 3 remains unchanged.
[0052] In a preferred embodiment of the flow-adjustable gas circulation output device of this application, such as Figure 4 and Figure 5As shown, the flange circulation hole 411 and flange bypass hole 412 provided on the regulating valve flange 41 are both round holes. The diameter of the flange circulation hole 411 is larger than the diameter of the flange bypass hole 412. Therefore, when the bypass valve port 402 is closed, that is, when the valve plate bypass hole 422 and the flange bypass hole 412 do not overlap, the impeller 3 can drive a larger flow of gas through the circulating air inlet 44, the flange circulation hole 411, the valve plate circulation hole 421, the fan outlet 21 and the circulating gas outlet 6 for circulation output.
[0053] The valve plate circulation hole 421 on the rotary valve plate 42 is a circular hole with the same diameter as the flange circulation hole 411. The valve plate bypass hole 422 on the rotary valve plate 42 is a waist-shaped hole with two radial sides that are arcs centered on the rotation axis of the rotary valve plate 42 and two circumferential sides that are semicircles. The distance between the two radial sides is equal to the diameter of the flange bypass hole 412, and the diameter of the arcs on the two circumferential sides is equal to the diameter of the flange bypass hole 412.
[0054] The relative position between the valve plate bypass hole 422 and the valve plate circulation hole 421, and the arc lengths of the two radial sides of the valve plate bypass hole 422 are set such that when the rotating valve plate 42 rotates to such a position... Figure 4 When the area of the circulating valve port 401 shown is equal to the area of the valve plate bypass port 422, the valve plate bypass port 422 and the flange bypass port 412 initially overlap; when the circulating valve plate 42 rotates to the point where... Figure 5 The valve plate circulation hole 421 shown is exactly not overlapping with the flange circulation hole 411. That is, when the circulation valve port 401 is just closed, the flange bypass hole 412 and the valve plate bypass hole 422 are still in a state of complete overlap, that is, the bypass valve port 402 is still in the state of maximum flow area.
[0055] By setting the relative positions of the valve plate bypass hole 422 and the valve plate circulation hole 421 in this embodiment, it is possible to ensure that as the area of the circulation valve port 401 gradually transitions from the size of the valve plate bypass hole 422 to zero, the area of the bypass valve port 402 gradually increases from zero to its maximum area and remains at the maximum area. This ensures that throughout the entire adjustment process of the flow area ratio between the circulation valve port 401 and the bypass valve port 402, the sum of the flow areas of the circulation valve port 401 and the bypass valve port 402 is always greater than that of the valve plate bypass hole 422. This avoids excessive flow resistance of the gas driven by the impeller 3, which would lead to excessive driving load on the variable frequency motor 1, and heat generation from the compression of the flowing gas. It also ensures that the variable frequency motor 1 is always under a low operating load and reduces energy consumption from cooling the circulating gas.
[0056] As one specific embodiment of the flow-adjustable gas circulation output device of this application, such as Figure 4 and Figure 5As shown, when the rotary valve plate 42 rotates to the point where the distance between the center of the valve plate circulation hole 421 and the center of the flange circulation hole 411 is equal to the diameter of the valve plate circulation hole 421, that is, when the edge of the valve plate circulation hole 421 is tangent to the edge of the flange circulation hole 411, a pointed groove 4211 protruding towards the center of the flange circulation hole 411 is provided at the tangent point between the edge of the valve plate circulation hole 421 and the flange circulation hole 411. When the rotary valve plate 42 rotates to the position where the valve plate circulation hole 421 and the flange circulation hole 411 are tangent, the valve plate circulation hole 421 still overlaps with the flange circulation hole 411 by a small area through the pointed groove 4211, forming a very small circulation valve port 401 area. This makes the flow area ratio of the circulation valve port 401 to the bypass valve port 402 reach a lower level, such as 1:9-1:99. Meanwhile, since the width of the slit 4211 has a relatively gentle and gradual reduction process, the flow area of the circulation valve port 401 decreases more slowly at a lower level as the rotary valve plate 42 rotates. This improves the degree of reduction of the flow area of the circulation valve port 401, which can be controlled more precisely, and improves the adjustment accuracy of the circulating gas flow at a lower level.
[0057] Before the pointed groove 4211 is separated from the flange circulation hole 411, the flange bypass hole 412 and the valve plate bypass hole 422 are always in a state of complete overlap, that is, the flow area of the bypass valve port 402 remains unchanged. This makes the flow area ratio of the circulation valve port 401 and the bypass valve port 402 determined only by the flow area of the circulation valve port 401, simplifying the adjustment process of the flow area ratio of the circulation valve port 401 and the bypass valve port 402, and ensuring the adjustment accuracy of the flow area ratio of the circulation valve port 401 and the bypass valve port 402.
[0058] Through the above settings, the flow area ratio between the circulation valve port 401 and the bypass valve port 402 can be precisely controlled to a maximum of 1:499. Combined with the control of the variable frequency motor 1 speed from 5Hz to 50Hz (ten times the speed), the flow-adjustable gas circulation output device of this application can achieve a circulating gas output flow rate from 0.8m³ / h. 3 / h to 8000m 3 It offers precise control over a flow range of 10,000 times per hour and can keep flow fluctuations below 0.5%.
[0059] In some embodiments of the flow-adjustable gas circulation output device of this application, such as Figures 3 to 5 As shown, valve plate drive teeth 423 are provided on the outer peripheral surface of the rotary valve plate 42, and motor gear 431 is provided on the output shaft of the valve plate motor 43. The motor gear 431 meshes with the valve plate drive teeth 423, so that a high reduction ratio reduction transmission is formed between the valve plate motor 43 and the rotary valve plate 42, which improves the control accuracy of the rotation position of the rotary valve plate 42 by controlling the rotation time and rotation angle of the valve plate motor 43.
[0060] In a preferred embodiment of the flow-adjustable gas circulation output device of this application, a controller is also provided. An angular displacement sensor 413 is also provided on the regulating valve flange 41. The angular displacement sensor 413 is positioned opposite to the rotary valve plate 42 and connected to the controller. The angular displacement sensor 413 can detect the actual rotational position of the rotary valve plate 42 and transmit this information to the controller. The controller can then adjust the valve plate motor 43 based on the actual rotational position of the rotary valve plate 42, ensuring the control accuracy of the rotational position of the rotary valve plate 42.
[0061] The valve plate motor 43 is selected as a CNC drive motor, such as a stepper motor or a servo motor. The controller is connected to the control signal interface of the valve plate motor 43. The controller can send control signals to accurately control the rotation angle of the valve plate motor 43, which further improves the control accuracy of the rotation position of the rotary valve plate 42.
[0062] In some embodiments of the flow-adjustable gas circulation output device of this application, such as Figure 1 and Figure 2 As shown, a temperature regulator 7 is installed between the fan outlet 21 and the circulating gas outlet 6 on the housing 2. The temperature regulator 7 can use various devices capable of adjusting the temperature of the gas output from the impeller 3, such as a constant-temperature refrigeration device or a temperature-controlled heat exchanger. During the use of the circulating gas output through the circulating gas outlet 6 in external equipment, such as during flow meter calibration in a flow calibration system, the temperature of the circulating gas usually rises. Flow meter calibration typically requires a low set temperature, such as 0°C. To ensure that the temperature of the circulating gas output through the circulating gas outlet 6 remains at a low set temperature level, the temperature regulator 7 usually needs to cool the gas flowing out of the fan outlet 21, thereby ensuring the stability of the circulating gas temperature output from the circulating gas outlet 6.
[0063] Typically, the temperature regulator 7 is connected to the housing 2, so that the fan outlet 21 is connected to the air inlet of the temperature regulator 7. The gas flowing out of the fan outlet 21 first enters the temperature regulator 7 for cooling, and the gas at the set temperature flows out from the outlet of the temperature regulator 7. The circulating gas outlet 6 is connected to the outlet of the temperature regulator 7. One end of the return bypass 5 is connected to the outlet pipe of the temperature regulator 7, and the other end is connected to the bypass air inlet 45 on the return regulating valve 4. Part of the gas output by the temperature regulator 7 flows back directly to the housing 2 through the return bypass 5 and the return regulating valve 4. Since this part of the gas does not flow into external equipment, it remains at a lower set stable state. This means that when the circulating gas is output at a low flow rate, only a small portion of the circulating gas temperature rises, while the temperature of most of the bypass gas remains at a low temperature. Therefore, the temperature regulation load of the temperature regulator 7 is very small, which speeds up the temperature regulation time of the temperature regulator 7, reduces the power consumption of the temperature regulation of the temperature regulator 7, and extends the service life of the temperature regulator 7.
[0064] In a preferred embodiment of the flow-adjustable gas circulation output device of this application, such as Figure 1 and Figure 2 As shown, the reflux regulating valve 4 and the temperature regulator 7 are respectively located at opposite ends of the housing 2. The variable frequency motor 1 is located inside the housing 2, and the impeller 3 is fixed on the output shaft of the variable frequency motor 1. The rotation of the variable frequency motor 1 drives the impeller 3 to rotate. The impeller 3 drives the circulating gas to flow in through the circulation valve port 401 of the reflux regulating valve 4, or simultaneously drives the bypass gas to flow in through the bypass valve port 402 of the reflux regulating valve 4. The gas flows through the gap between the variable frequency motor 1 and the housing 2 and flows out through the fan outlet 21 located on the end face of the housing 2 opposite to the reflux regulating valve 4. The gas then flows into the temperature regulator 7 fixed on the end face of the housing 2 for temperature regulation.
[0065] In some embodiments of the flow-adjustable gas circulation output device of this application, such as Figure 6 and Figure 7 As shown, the reflux regulating valve 4 and the temperature regulator 7 are respectively located at opposite ends of the housing 2. The variable frequency motor 1 is mounted on the reflux regulating valve 4 and fixed to the side end face of the reflux regulating valve 4 located outside the housing 2. The impeller 3 is located inside the housing 2, opposite to the variable frequency motor 1, and the rotating shaft of the impeller 3 passes through the reflux regulating valve 4 and is opposite to the output shaft of the variable frequency motor 1. Specifically, a rotating bushing is provided in the middle of the regulating valve flange 41. The outer side of the rotating bushing is fixedly connected to the regulating valve flange 41 and the valve plate cover 47, and rotatably connected to the rotating valve plate 42. The inner side of the rotating bushing is rotatably connected to the rotating shaft of the impeller 3.
[0066] A magnetic connector 8 is provided between the output shaft of the variable frequency motor 1 and the rotating shaft of the impeller 3. The magnetic connector 8 includes a driving half-coupling 81 and a driven half-coupling 82. The driven half-coupling 82 is fixed to the end of the rotating shaft of the impeller 3. An isolation cover 22 is fixedly provided on the return flow regulating valve 4 outside the driven half-coupling 82. The isolation cover 22 is sealed to the return flow regulating valve 4 to ensure the isolation between the internal space and the external space of the housing 2. The driven half-coupling 82 is located inside the isolation cover 22 and can rotate freely inside the isolation cover 22.
[0067] The active half-coupling 81 is configured as a cylindrical shape with one end open. The closed end of the active half-coupling 81 is fixed on the output shaft of the variable frequency motor 1, and the open end is sleeved on the outside of the isolation cover 22 and can rotate freely on the outside of the isolation cover 22.
[0068] A high-strength permanent magnet is installed on the driving half-coupling 81, and a corresponding high-strength permanent magnet with opposite magnetic properties is installed on the driven half-coupling 82. The isolation cover 22 is made of non-ferromagnetic material, so that a magnetic connection is formed between the driving half-coupling 81 and the driven half-coupling 82. This allows the impeller 3 to rotate via the variable frequency motor 1 while ensuring a reliable seal at the drive connection. The gas inside the impeller-driven housing 2 flows into the temperature regulator 7 through the fan outlet 21 on the end face of the housing 2.
[0069] In other embodiments of the flow-adjustable gas circulation output device of this application, such as Figure 8 and Figure 9 As shown, the variable frequency motor 1 and the return flow regulating valve 4 are respectively installed at opposite ends of the housing 2. The variable frequency motor 1 is installed outside the housing 2, and the fan outlet 21 is installed on the side wall of the housing 2.
[0070] The impeller 3 is disposed inside the housing 2, and its rotating shaft extends through the end of the housing 2 to the outside of the housing 2, opposite to the output shaft of the variable frequency motor 1 fixed to the outer end face of the housing 2. A rotating bushing may also be disposed between the output shaft of the variable frequency motor 1 and the housing 2, the rotating bushing being fixedly connected to the housing 2 and rotatably connected to the output shaft of the variable frequency motor 1. A magnetic connector 8 is disposed between the output shaft of the variable frequency motor 1 and the rotating shaft of the impeller 3, the magnetic connector 8 including a driving half-coupling 81 and a driven half-coupling 82.
[0071] The driven half-coupling 82 is fixed to the end of the rotating shaft of the impeller 3. An isolation cover 22 is fixedly installed on the end face of the outer housing 2 of the driven half-coupling 82. The isolation cover 22 is sealed to the housing 2 to ensure the isolation between the internal space and the external space of the housing 2. The driven half-coupling 82 is located inside the isolation cover 22 and can rotate freely inside the isolation cover 22.
[0072] The active half-coupling 81 is configured as a cylindrical shape with one end open. The closed end of the active half-coupling 81 is fixed on the output shaft of the variable frequency motor 1, and the open end is sleeved on the outside of the isolation cover 22 and can rotate freely on the outside of the isolation cover 22.
[0073] A high-strength permanent magnet is installed on the driving half-coupling 81, and a corresponding high-strength permanent magnet with opposite magnetic properties is installed on the driven half-coupling 82. The isolation cover 22 is made of non-ferromagnetic material, so that a magnetic connection is formed between the driving half-coupling 81 and the driven half-coupling 82. This allows the impeller 3 to rotate via the variable frequency motor 1 while ensuring a reliable seal at the drive connection. The gas inside the impeller-driven housing 2 flows out from the fan outlet 21 on the side wall of the housing 2 and enters the temperature regulator 7 located on one side of the housing 2. The temperature regulator 7 can be fixed to the side wall of the housing 2, or it can be fixed to the same mounting bracket as the housing 2 and fixed to one side of the housing 2 on the mounting bracket.
[0074] One embodiment of the flow calibration system of this application uses the flow-adjustable gas circulation output device of any embodiment of this application, and also has the advantages of the flow-adjustable gas circulation output device of the corresponding embodiment.
[0075] In the description of this application, the references to terms such as "an embodiment," "specific embodiment," and "preferred embodiment" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0076] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A gas circulation output device with adjustable flow rate, characterized in that: The system includes a variable frequency motor (1), a housing (2), an impeller (3), a reflux regulating valve (4), a reflux bypass (5), and a circulating gas outlet (6). The variable frequency motor (1) is driven and connected to the impeller (3). The impeller (3) is located inside the housing (2). The housing (2) is provided with a fan outlet (21). The reflux regulating valve (4) is located on the housing (2) and includes a circulation valve port (401) and a bypass valve port (402). The reflux regulating valve (4) can adjust the reflux valve port (401) and the bypass valve port (402). The impeller (3) can drive gas through the circulation valve port (401) and the bypass valve port (402) to the fan outlet (21). The circulation gas output port (6) is connected to the fan outlet (21). One end of the return bypass (5) is connected to the connection passage between the circulation gas output port (6) and the fan outlet (21), and the other end is connected to the bypass valve port (402). The circulation valve port (401) is connected to the output gas circulation loop.
2. The flow-adjustable gas circulation output device according to claim 1, characterized in that: The reflux regulating valve (4) includes a regulating valve flange (41), a rotary valve plate (42), and a valve plate motor (43). The regulating valve flange (41) is provided with a flange circulation hole (411) and a flange bypass hole (412). The rotary valve plate (42) is provided with a valve plate circulation hole (421) and a valve plate bypass hole (422). The rotary valve plate (42) is rotatably mounted on the regulating valve flange (41). The valve plate motor (43) is fixed on the regulating valve flange (41) on the side opposite to the rotary valve plate (42), and the drive shaft passes through the regulating valve flange (41) and is driven to connect with the rotary valve plate (42) so as to drive the rotary valve plate (42) to rotate. The valve plate circulation hole (421) overlaps with the flange circulation hole (411) to form the circulation valve port (401). The valve plate bypass hole (422) overlaps with the flange bypass hole (412) to form the bypass valve port (402).
3. The flow-adjustable gas circulation output device according to claim 2, characterized in that: Both the flange circulation hole (411) and the flange bypass hole (412) are circular holes. The diameter of the flange circulation hole (411) is larger than the diameter of the flange bypass hole (412). The valve plate circulation hole (421) is a circular hole with the same diameter as the flange circulation hole (411). The valve plate bypass hole (422) is an oblong hole with two sides centered on the rotation axis of the rotating valve plate (42), and the distance between the two sides is equal to the diameter of the flange bypass hole (412). The relative positions of the valve plate circulation hole (421) and the valve plate bypass hole (422) are configured such that when the rotating valve plate (42) rotates to the point where the area of the circulation valve port (401) is equal to the area of the valve plate bypass hole (422), the valve plate bypass hole (422) and the flange bypass hole (412) begin to overlap each other, and when the circulation valve port (401) is closed, the flange bypass hole (412) is still in a state of complete overlap with the valve plate bypass hole (422).
4. The flow-adjustable gas circulation output device according to claim 3, characterized in that: When the rotary valve plate (42) rotates to the point where the distance between the center of the valve plate circulation hole (421) and the center of the flange circulation hole (411) is equal to the diameter of the valve plate circulation hole (421), a pointed groove (4211) protruding towards the center of the flange circulation hole (411) is provided on the side of the valve plate circulation hole (421) adjacent to the flange circulation hole (411). Before the pointed groove (4211) is separated from the flange circulation hole (411), the flange bypass hole (412) is still in a state of complete overlap with the valve plate bypass hole (422).
5. The flow-adjustable gas circulation output device according to claim 2, characterized in that: The outer circumferential surface of the rotary valve plate (42) is provided with valve plate drive teeth (423), and the output shaft of the valve plate motor (43) is provided with motor gear (431), which meshes with the valve plate drive teeth (423).
6. The flow-adjustable gas circulation output device according to claim 5, characterized in that: It also includes a controller, and an angular displacement sensor (413) is provided on the regulating valve flange (41) opposite to the rotary valve plate (42). The valve plate motor (43) is a CNC drive motor. The angular displacement sensor (413) and the valve plate motor (43) are both connected to the controller.
7. The flow-adjustable gas circulation output device according to any one of claims 1-6, characterized in that: A temperature regulator (7) is provided between the fan outlet (21) and the circulating gas outlet (6), and the return bypass (5) is connected between the temperature regulator (7) and the circulating gas outlet (6).
8. The flow-adjustable gas circulation output device according to claim 7, characterized in that: The reflux regulating valve (4) and the temperature regulator (7) are respectively located at opposite ends of the housing (2). The variable frequency motor (1) is located inside the housing (2). The impeller (3) is fixed on the output shaft of the variable frequency motor (1). The fan outlet (21) is located on the end face of the housing (2) connected to the temperature regulator (7).
9. The flow-adjustable gas circulation output device according to claim 7, characterized in that: The reflux regulating valve (4) and the temperature regulator (7) are respectively located at opposite ends of the housing (2), and the variable frequency motor (1) is located on the reflux regulating valve (4); or the variable frequency motor (1) and the reflux regulating valve (4) are respectively located at opposite ends of the housing (2), and the fan outlet (21) is located on the side wall of the housing (2); The variable frequency motor (1) is disposed outside the housing (2). The output shaft of the variable frequency motor (1) is disposed opposite to the rotation shaft of the impeller (3). A magnetic connector (8) is disposed between the output shaft of the variable frequency motor (1) and the rotation shaft of the impeller (3). The magnetic connector (8) includes a driving half-coupling (81) and a driven half-coupling (82). The rotation shaft of the impeller (3) extends through the reflux regulating valve (4) or the housing (2) to the outside of the housing (2). The driven half-coupling (82) is fixed to the rotation of the impeller (3). On the shaft, an isolation cover (22) is provided on the outside of the reflux regulating valve (4) or the housing (2). The isolation cover (22) is sealed to the reflux regulating valve (4) or the housing (2), so that the driven half coupling (82) is located inside the isolation cover (22). The driving half coupling (81) is cylindrical. One end of the driving half coupling (81) is fixed on the output shaft of the variable frequency motor (1), and the other end is sleeved on the outside of the isolation cover (22). The driving half coupling (81) and the driven half coupling (82) are magnetically connected.
10. A flow rate determination system, characterized in that: Includes a flow-adjustable gas circulation output device according to any one of 1-9.