Air volume control valve capable of accurately measuring air volume

Abstract

An air volume control valve capable of accurately measuring an air volume is provided. The air volume control valve includes a round-shaped valve body, and a valve blade and an orifice plate provided in the round-shaped valve body, where the orifice plate is located upstream of the valve blade; an upstream pressure tapping port and a downstream pressure tapping port are respectively provided upstream and downstream of the orifice plate; a distance from both the upstream pressure tapping port and the downstream pressure tapping port to the orifice plate is 0.5 times a valve diameter; the valve blade is located downstream of the downstream pressure tapping port; an inlet side of the round-shaped valve body is provided with a convergent duct fitting; and the convergent duct fitting is located at a distance of once the valve diameter upstream of the orifice plate and is tapered along an air flow direction.

Claims

1. An air volume control valve capable of accurately measuring an air volume, comprising a round-shaped valve body, and a valve blade and an orifice plate provided in the round-shaped valve body, wherein the orifice plate is located upstream of the valve blade; an upstream pressure tapping port and a downstream pressure tapping port are respectively provided upstream and downstream of the orifice plate; a distance from both the upstream pressure tapping port and the downstream pressure tapping port to the orifice plate is 0.5 times a valve diameter of the round-shaped valve body; and the valve blade is located downstream of the downstream pressure tapping port; and an inlet side of the round-shaped valve body is provided with a convergent duct fitting; and the convergent duct fitting is located at a distance of one times the valve diameter upstream of the orifice plate and is tapered along an air flow direction; wherein the orifice plate is provided with a circular inner hole; and the circular inner hole has a diameter that is 0.2-0.8 times the valve diameter; wherein the round-shaped valve body is divided into an air volume measurement section and an air volume regulation section; the air volume measurement section is centered on the orifice plate and has a length that is twice the valve diameter; and the air volume regulation section is centered on a shaft of the valve blade.

2. The air volume control valve capable of accurately measuring the air volume according to claim 1, further comprising a pressure differential transducer, a microcontroller, and an actuator, wherein the pressure differential transducer is connected to the upstream pressure tapping port and the downstream pressure tapping port through an upstream pressure tapping tube and a downstream pressure tapping tube, respectively; the pressure differential transducer is connected to the microcontroller; the microcontroller is connected to the actuator; and the actuator is configured to control an action of the valve blade.

3. The air volume control valve capable of accurately measuring the air volume according to claim 2, wherein a protective shell is fitted outside the round-shaped valve body at the orifice plate, the upstream pressure tapping port, and the downstream pressure tapping port; and the pressure differential transducer, the microcontroller, the upstream pressure tapping tube, and the downstream pressure tapping tube are located inside the protective shell.

4. The air volume control valve capable of accurately measuring the air volume according to claim 2, wherein an angle of the convergent duct fitting is 5-30.

5. The air volume control valve capable of accurately measuring the air volume according to claim 2, wherein the round-shaped valve body has the valve diameter of 150 mm, 200 mm, 250 mm, 300 mm, or 400 mm.

6. The air volume control valve capable of accurately measuring the air volume according to claim 2, wherein there is a single or multiple valve blades.

7. The air volume control valve capable of accurately measuring the air volume according to claim 1, wherein an angle of the convergent duct fitting is 5-30.

8. The air volume control valve capable of accurately measuring the air volume according to claim 7, wherein an outlet side of the round-shaped valve body is provided with a divergent duct fitting that gradually expands along the air flow direction.

9. The air volume control valve capable of accurately measuring the air volume according to claim 1, wherein the round-shaped valve body has the valve diameter of 150 mm, 200 mm, 250 mm, 300 mm, or 400 mm.

10. The air volume control valve capable of accurately measuring the air volume according to claim 1, wherein there is a single or multiple valve blades.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above is only an overview of the technical solutions of the present disclosure. In order to understand the technical means of the present disclosure more clearly, the present disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

(2) FIG. 1 is a section view of an air volume control valve capable of accurately measuring an air volume (the arrow indicates an air flow direction) according to an embodiment of the present disclosure;

(3) FIG. 2 is a perspective view of the air volume control valve according to an embodiment of the present disclosure;

(4) FIG. 3 is a front view of the air volume control valve according to an embodiment of the present disclosure; and

(5) FIG. 4 is a detail of a part A shown in FIG. 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(6) Exemplary embodiments of the present disclosure will be described in detail below with reference to the drawings. Although the accompanying drawings show exemplary embodiments of the present disclosure, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. The embodiments are provided to provide a more thorough understanding of the present disclosure, and the scope of the present disclosure can be fully conveyed to those skilled in the art.

(7) The overall design concept of the present disclosure is to provide an orifice plate, which matches a convergent duct fitting upstream of the orifice plate, inside an air volume control valve, and to set the positions of upstream and downstream pressure tapping ports. In this way, during installation, there is no requirement for an upstream straight duct section and a low operating pressure differential, and accurate measurement and control of the air volume can be achieved.

(8) Based on the theory of fluid mechanics, it is possible to establish the corresponding relationship between the pressure drop of any rigid resistance component such as an orifice plate or nozzle in a gas conduit and the gas flow rate, thereby achieving the measurement of air volume. However, in practical applications, certain conditions must be strictly met to achieve measurement accuracy and consistency. In the Chinese national standard GB/T2624.2-2006 (an equivalent of ISO5167-2:2003) Measurement of Fluid Flow by Means of Pressure Differential Devices Inserted in Circular Cross-section Conduits Running Full-Part 2: Orifice Plates, Table 3 shows the requirements for the required straight duct section between the orifice plate and the duct fitting without a stream straightener. For example, the minimum distance (length) from the elbow upstream of the orifice plate to the straight duct section of the orifice plate is 3 times the valve diameter (when the ratio of the inner diameter of the orifice plate to the diameter of the air duct is less than or equal to 0.20). When the diameter ratio is 0.75, the straight duct section must reach at least 20 times the valve diameter. This standard also puts forward a requirement for the positions of the pressure tapping ports before and after the orifice plate. That is, the distance from the pressure tapping port upstream of the orifice plate to the orifice plate is once the valve diameter, and the distance from the downstream pressure tapping port to the orifice plate is 0.5 times the valve diameter. Due to the extremely strict requirements, orifice flow meters are only used as aerodynamic testing devices in air conditioning and ventilation systems and cannot be used as a means of measuring air volume in building engineering systems.

(9) The present disclosure makes an adjustment to the above-mentioned orifice plate and applies it to an air volume control valve, as shown in FIGS. 1 to 4.

(10) An embodiment provides an air volume control valve capable of accurately measuring an air volume, including round-shaped valve body 1. The round-shaped valve body 1 can adopt different valve diameters D as needed, which can be 150 mm, 200 mm, 250 mm, 300 mm, or 400 mm. The round-shaped valve body 1 is provided therein with single or multiple valve blades 2. The valve blade 2 is rotatable along the shaft 21 to regulate the air volume.

(11) The round-shaped valve body 1 is further provided therein with orifice plate 3. The orifice plate 3 is located upstream of the valve blade 2. The orifice plate 3 is provided with a circular inner hole with diameter d being 0.2-0.8 times a valve diameter (d=0.2-0.8 D). As shown in FIG. 3, the opening of the orifice plate 3 can be rounded, angled, or without chamfering. Upstream pressure tapping port 4 and downstream pressure tapping port 5 are respectively provided upstream and downstream of the orifice plate 3. A distance from both the upstream pressure tapping port 4 and the downstream pressure tapping port 5 to the orifice plate 3 is 0.5 times the valve diameter. The valve blade 2 is located downstream of the downstream pressure tapping port 5.

(12) An inlet side of the round-shaped valve body 1 is provided with convergent duct fitting 6. The convergent duct fitting 6 is located at a distance of once the valve diameter upstream of the orifice plate 3 and is tapered along an air flow direction. The angle of the convergent duct fitting 6 is preferably 10-30. The convergent duct fitting 6 can be changed from a rectangle to a circle or from a circle to a circle.

(13) An outlet side of the round-shaped valve body 1 is provided with divergent duct fitting 7, which gradually expands along the air flow direction. Due to the same diameter of the air duct, the diameters at two ends of the air volume control valve are the same. The divergent duct fitting 7 is mainly designed to cooperate with the convergent duct fitting 6 to connect the downstream air duct.

(14) The round-shaped valve body 1 of the air volume control valve can be divided into two sections: an air volume measurement section and an air volume regulation section. The air volume measurement section is centered on the orifice plate 3 and has a length that is twice the valve diameter (2D). The air volume regulation section is centered on the shaft 21 of the valve blade 2 and has a length of L.

(15) The air volume control valve further includes pressure differential transducer 8, microcontroller 9, and actuator 10. The pressure differential transducer 8 is connected to the upstream pressure tapping port 4 and the downstream pressure tapping port 5 through upstream pressure tapping tube 11 and downstream pressure tapping tube 12, respectively. The pressure differential transducer 8 is connected to the microcontroller 9. The microcontroller 9 is connected to the actuator 10. The actuator 10 is configured to control an action of the valve blade 2.

(16) Protective shell 13 is fitted outside the round-shaped valve body at the orifice plate 3, the upstream pressure tapping port 4, and the downstream pressure tapping port 5. The pressure differential transducer 8, the microcontroller 9, the upstream pressure tapping tube 11, and the downstream pressure tapping tube 12 are located inside the protective shell 13.

(17) The air volume control valve of the present disclosure can achieve air volume measurement in the absence of a straight duct section upstream, with the error not exceeding 3% within the designed air volume range. The present disclosure meets the requirements of general air conditioning and ventilation engineering for air volume measurement accuracy, creates conditions for air volume regulation and control.

(18) Tables 4 and 5 show the comparison between the air volume measurement values of the 200 mm (valve diameter of the round-shaped valve body) air volume control valve downstream of an elbow and a tee in the present disclosure and the measurement values of a sampling standard nozzle flowmeter. It can be seen that the deviation from the standard air volume is less than 3%. According to the experimental results, the measured data within the designed air volume range shows that the air volume measurement deviations of the other four devices of different specifications (diameters of 150 mm, 250 mm, 300 mm, and 400 mm) are also less than 3%.

(19) TABLE-US-00004 TABLE 4 Comparison between the air volume measurement values of the 200 mm air volume control valve downstream of the elbow (without a straight duct section) in the present disclosure and the standard air volume Actual air Average air velocity Air volume readings Deviation volume (m.sup.3/h) inside duct m/s by valve (m.sup.3/h) % 1008.0 8.91 1024.5 1.63 1011.9 8.95 1025.8 1.38 1010.6 8.94 1026.5 1.58 1003.5 8.87 1019.2 1.56 991.3 8.76 1006.8 1.56 972.9 8.60 988.5 1.60 943.9 8.35 960.5 1.75 896.4 7.93 912.1 1.76 868.5 7.68 881.6 1.51 837.7 7.41 850.8 1.56 792.8 7.01 804.8 1.51 750.5 6.64 759.1 1.15 719.9 6.37 731.1 1.55 664.9 5.88 674.7 1.47 628.3 5.56 633.3 0.79 613.0 5.42 626.1 2.13 582.3 5.15 591.9 1.65 546.3 4.83 557.2 2.00 502.6 4.44 511.1 1.69 462.6 4.09 471.4 1.89 419.4 3.71 426.9 1.79 368.1 3.25 373.7 1.52 340.2 3.01 347.8 2.22 307.8 2.72 312.8 1.60 266.0 2.35 270.4 1.66

(20) TABLE-US-00005 TABLE 5 Comparison between the air volume measurement values of the 200 mm air volume control valve downstream of the tee branch (without a straight duct section) in thepresent disclosure and the standard air volume Actual air Average air velocity Air volume readings Deviation volume (m.sup.3/h) inside duct m/s by valve (m.sup.3/h) % 1010.6 8.94 1027.1 1.63 1013.0 8.96 1028.8 1.56 1008.6 8.92 1025.1 1.64 994.9 8.80 1013.1 1.83 983.6 8.70 999.5 1.62 962.5 8.51 981.1 1.93 925.6 8.18 942.6 1.84 901.1 7.97 916.9 1.75 873.4 7.72 886.5 1.51 834.2 7.38 847.6 1.61 805.5 7.12 819.7 1.77 740.9 6.55 751.5 1.43 708.0 6.26 715.6 1.07 675.6 5.97 678.6 0.44 636.1 5.62 641.1 0.78 588.5 5.20 596.7 1.41 528.0 4.67 533.0 0.95 497.0 4.39 503.3 1.26 465.1 4.11 467.4 0.51 431.6 3.82 433.6 0.46 399.4 3.53 397.8 0.38 352.2 3.11 347.0 1.46 317.1 2.80 312.9 1.33 285.4 2.52 280.8 1.62 281.8 2.49 284.8 1.06 235.2 2.08 236.2 0.45

(21) In the present disclosure, according to the test of the performance of the 200 mm air volume control valve downstream of the elbow and the tee branch, the averaged stable values and deviations are shown in Tables 6 and 7, with deviations less than 3%.

(22) TABLE-US-00006 TABLE 6 Actual air volume control performance of the 200 mm air volume control valve downstream of the elbow (without a straight duct section) in the present disclosure Air volume set point Actual air Average air velocity Deviation (m.sup.3/h) volume (m.sup.3/h) inside duct m/s % 350 353.3 3.1 0.9 650 643.1 5.7 1.1 900 890.6 7.9 1.0

(23) TABLE-US-00007 TABLE 7 Actual air volume control performance of the 200 mm air volume control valve downstream of the tee (without a straight duct section) in the present disclosure Air volume set point Actual air Average air velocity Deviation (m.sup.3/h) volume (m.sup.3/h) inside duct m/s % 350 359.9 3.2 2.8 650 649.8 5.7 0.03 900 898.6 7.9 0.2

(24) In addition, in the present disclosure, through testing, the recommended operating air volume range and corresponding pressure drops of the air volume control valves are shown in Table 8.

(25) TABLE-US-00008 TABLE 8 Recommended air volume range and corresponding pressure drops of air volume control valves in the present disclosure Valve diameter Recommended air volume Pressure drop mm range (m.sup.3/h) range Pa 150 150-450 14-117 200 350-800 24-120 250 500-1250 20-115 300 550-1800 11-110 400 900-3100 10-114

(26) Tables 4 to 8 are the testing results of the air volume control valve based on the data in Table 9.

(27) TABLE-US-00009 TABLE 9 Inner hole diameter of the orifice plate 3 and angle of the convergent duct fitting 6 for the air volume control valves in the present disclosure Valve Inner hole diameter Angle of the convergent duct fitting 6 diameter of the orifice plate From round duct to From rectangular mm 3 mm round duct duct to round duct 150 30-120 30 5-30 200 40-160 30 5-30 250 50-200 30 5-30 300 60-240 30 5-30 400 80-320 30 5-30

(28) After testing and verification, a similar effect can be achieved when the inner hole diameter d of the orifice plate 3 is 0.2-0.8 times the valve diameter (d=0.2-0.8 D) and the angle of the convergent duct fitting 6 is 5-30.

(29) Overall, in the air volume control valve of the present disclosure, the orifice plate is located upstream of the valve blade, the convergent duct fitting is located at the inlet side of the round-shaped valve body, and the upstream and downstream pressure tapping ports are located at a distance of 0.5 times the valve diameter upstream and downstream of the orifice plate, respectively. In this way, the present disclosure can achieve air volume measurement in the absence of a straight duct section upstream, with the error not exceeding 3% within the designed air volume range. The present disclosure meets the requirements of general air conditioning and ventilation engineering for air volume measurement accuracy, creates conditions for air volume regulation and control. In addition, the present disclosure has a requirement for a low pressure differential across the air volume control valve, suitable for application.

(30) The above are only preferred embodiments of the present disclosure, and are not intended to limit the present disclosure in any form. Simple alterations, equivalent changes or modifications made by those skilled in the art make using the technical contents disclosed above fall within the scope of protection of the present disclosure.