CN201795822U - High-precision large-scale gas flow meter - Google Patents
High-precision large-scale gas flow meter Download PDFInfo
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- CN201795822U CN201795822U CN2009202441342U CN200920244134U CN201795822U CN 201795822 U CN201795822 U CN 201795822U CN 2009202441342 U CN2009202441342 U CN 2009202441342U CN 200920244134 U CN200920244134 U CN 200920244134U CN 201795822 U CN201795822 U CN 201795822U
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Abstract
A high-precision large-scale gas flow meter relates to gas flow meters and solves the problem that the distance between a measured section at an outlet of a gas inlet channel mould and a flow meter is larger, and measured value difference is larger to cause uneven total pressure distribution and larger deviation of measured total pressure values of the measured section from actual values so as to affect precision in gas flow measurement. The high-precision large-scale gas flow meter is characterized in that a transitional cavity of the flow meter is arranged on the left side, a diffusion cavity is arranged on the right side of the transitional cavity, a stabilizing cavity is arranged on the right side of the diffusion cavity, a central flow regulating cone is arranged on a cross web plate inside the diffusion cavity and supported by the cross web plate, the cross web plate is fixed onto a casing of the stabilizing cavity, a cellular device is arranged between two damping nets and fixed onto the casing of the stabilizing cavity, a contraction cavity is arranged at the left end of a nozzle, the left end of the nozzle is connected with a casing of the contraction cavity, and the gas flow meter is connected with the measured section of the outlet of the gas channel mould. The high-precision large-scale gas flow meter has the advantages of simple structure, small volume and size, small interference and high measurement precision.
Description
Technical field
The utility model belongs to aircraft air intake duct wind tunnel instrumentation, is specifically related to a kind of novel high-precision air flow meter on a large scale.
Background technology
At present, when carrying out the aircraft air intake test, coefficient of flow can by air intake duct model outlet measuring section with pipeline that measuring section links to each other on flowmeter record, because measuring section directly links to each other with the air intake duct outlet, when burbling appears in inlet lip or inner-walls of duct, can cause bigger stagnation pressure skewness, the stagnation pressure value and the actual value deviation that cause measuring section to record are bigger, influence the accuracy of flow measurement.The general measurement result that adopts air flow meter when therefore, estimating the performance of air intake duct.And existing air flow meter is made up of adapter cavity, restriction portion, stable cavity, the awl that dams, servomotor, speed reduction unit, honeycomb, damping screen, total pressure measurement section, contraction chamber, static pressure measurement section and diffuser etc., can realize the measurement and the control of air flow rate simultaneously.In air intake test, be placed in the test chamber rear, link to each other with the outlet measuring section of test model by one section ventilation flexible rubber hose.Because air intake duct model outlet measuring section and air flow meter apart from each other, in test process, air flow rate and measuring section place measured value that the air flow meter place is measured differ bigger.Table 5 is that certain heavy caliber binary S type air intake duct measurement result of the two under different flow contrasts.The coefficient of flow unit rate of flow meter place measured value that records of measuring section is big as can be seen from Table 5, and its residual quantity is along with the increase of flow has the trend that reduces.The thermopair that is used for temperature compensation is subjected to have the servo driver of motor electromagnetic signal serious interference that flowmeter dams and bores now, and Temperature Influence amount maximum has been reached about 7 degrees centigrade, has had a strong impact on the effect of temperature compensation.
Summary of the invention
The utility model is in order to solve the air intake duct model outlet measuring section and the flowmeter apart from each other of existing air flow meter, in test process, flow and measuring section place measured value that the flowmeter place is measured differ bigger, because measuring section directly links to each other with the air intake duct outlet, when burbling appears in inlet lip or inner-walls of duct, can cause bigger stagnation pressure skewness, the stagnation pressure value and the actual value deviation that cause measuring section to record are bigger, influence the accuracy that air flow rate is measured; The problem that the overall dimensions of flowmeter is big provides a kind of air flow meter with high precision and large range, and the concrete technical scheme that addresses the above problem is as follows:
The utility model is a kind of air flow meter with high precision and large range, by diffusion chamber, stable cavity, contraction chamber, adapter cavity, the center fiaring cone, honeycomb, damping screen, nozzle and cross former are formed, adapter cavity is located at the left side of cavity, diffusion chamber is located at the right side of adapter cavity, stable cavity is located at the right of diffusion chamber, the center fiaring cone is located on the interior cross former of diffusion chamber, the center fiaring cone is provided with wire netting, the cross former is fixed on the housing of stable cavity, honeycomb is located in the middle of ground floor and the second layer damping screen, honeycomb and cloudy Buddhist nun's net are fixed on the housing of stable cavity, contraction chamber is located at the left end of nozzle, the left end of nozzle is connected with the housing of contraction chamber right-hand member, and the left end of air flow meter links to each other with air intake duct model outlet measuring section.
Described honeycomb is made up of the regular hexagon grid with certain-length, is fixed on all around on the housing of stable cavity.
The main effect of diffusion chamber is that the kinetic energy of air-flow is become the pressure energy.Consider to have selected big angle of release diffusion chamber for use from whole pipe-line layout in order to shorten diffusion chamber length and to reduce the pipeline charging volume.The size of big angle of release diffusion chamber " diffusion " loss can represent that this coefficient is the diffusion loss Δ P of diffusion chamber with impacting complete coefficient φ
MThe ratio of the theoretical impact loss of (both spread angle θ=90 °) during with the cross section sudden enlargement, that is:
Studies show that, in diffusion chamber spread angle θ=20 °～25 ° scope, φ＜1; When θ=25 °～45 °, φ＞1; And when θ=45 °～90 °, φ drops to φ → 1 from φ＞1.During these explanation θ＞(20 °～25 °), the pressure loss of diffusion chamber is also bigger than the loss of diffusion suddenly.According to top analysis, the selection spread angle is θ=20.25 °, like this (diffusion chamber entrance and exit diameter is respectively 116mm and 192mm), then L=103mm under the situation that diffusion chamber entrance and exit diameter has been determined.There is data to show that for this diffusion ratio 2.74, spread angle is 20.25 ° a situation, in diffusion chamber, will occurs a large amount of transient states and separate even the Disengagement zone that large tracts of land is fixed can occur.In order to reduce the pressure loss that this jet that separates fully brings, installed a center fiaring cone that supports by the cross former additional in the outlet of diffusion chamber, the cross former not only has supporting role here, can play the effect of smashing big whirlpool again.The center fiaring cone can make the attached again wall of free jet, stop burbling, air-flow is diffused into whole stable cavity cross section gets on, and all even stable flowing is provided.The cone angle of center fiaring cone has a significant effect to the Velocity Profiles and the pulsation level in downstream.In order to reduce the load of the conical surface, the center cone skeleton is selected the wire netting of suitable order number for use, in order to prevent influencing each other between angle spread chamber and the front air intake duct measuring section, install the adapter cavity that a suitable length has 3 ° of spread angle additional, can calculate fiaring cone awl bucket diameter according to this angle of flare and should be 97mm.Adopt angle spread chamber and center fiaring cone method for designing, wherein big angle of release diffusion chamber can shorten the overall dimensions of flowmeter, be provided with the Disengagement zone area that center fiaring cone that the cross former supports then can reduce the diffusion chamber porch in the outlet of diffusion chamber, improve the uniformity coefficient of stable cavity air-flow.
Stable cavity is the cylinder that equates with the diffusion chamber outlet diameter.For guaranteeing to access colory measurement flow field, install fairings such as honeycomb and damping screen additional in the upstream of stable cavity in the stable cavity downstream.The main effect of honeycomb is to lead straight air-flow and smash big whirlpool, and simultaneously, the pipeline in the honeycomb also helps the velocity distribution of improving air-flow to the friction of air-flow.Honeycomb adopts hexagonal grid, in order to improve the rectification effect of honeycomb, has data demonstration length-diameter ratio generally to choose in 6～8 scopes, but be subjected to the restriction of stable cavity length in the utility model, and the length-diameter ratio of finally choosing is 3.75.The stable cavity downstream is furnished with total pressure measurement point measurement air-flow stagnation pressure P
0
Contraction chamber adopts exchangeable nozzle, and its throat diameter is chosen according to aircraft air intake duct model outlet diameter.Contraction chamber quickens air-flow, improves the accuracy of static pressure measurement, is furnished with static pressure measurement point measurement air-flow static pressure P at contraction chamber venturi place.
Can calculate the mass rate m of air-flow by following formula.
In the formula: A-exchangeable nozzle throat area;
T
0-air-flow stagnation temperature records in flowmeter inlet the place ahead.
Advantage that the utlity model has and beneficial effect: air flow meter directly is connected with the model measurement section, has reduced air intake duct outlet measuring section and flowmeter survey cross section stagnation temperature T
0Residual quantity, make the two the more aligned property of measurement result; Because flowmeter has been realized structural the separation with flow control valve, thereby has reduced the interference of servo driver of motor to various sensor measurement electric signal greatly, improved the precision of measuring; Simultaneously, the flow regulating function owing to having removed in the new flowmeter in the former flowmeter makes the stable cavity size of new flowmeter reduce greatly; The nozzle of new flowmeter has formed seriation, can realize that by the nozzle of changing different size pipeline size accurately measures at the air flow rate of 50～100mm scope; That the utility model also has is simple in structure, volume size is little (existing relatively flowmeter length reduces about 1/3rd) and the high characteristics of measuring accuracy.
Description of drawings
Fig. 1 is a structural representation of the present utility model, and Fig. 2 is the structural representation of hexagonal lattice honeycomb, and Fig. 3 is the structural representation of cross former and center fiaring cone, and Fig. 4 is existing flowmeter structure synoptic diagram.8 is total pressure measurement points among the figure, the 9th, and the static pressure measurement point.
Embodiment
Embodiment one: describe present embodiment in conjunction with Fig. 1, Fig. 2, Fig. 3.Present embodiment is by diffusion chamber 1, stable cavity 2, contraction chamber 3, adapter cavity 4, center fiaring cone 5, honeycomb 6, damping screen 7, nozzle 10 and cross former 11 are formed, adapter cavity 4 is located at the left side, diffusion chamber 1 is located at the right side of adapter cavity 4, stable cavity 2 is located at the right of diffusion chamber 1, center fiaring cone 5 is located on the cross former 11 in the diffusion chamber 1, be fixed with 9～11 purpose wire nettings on the center fiaring cone 5, center fiaring cone 5 is fixed on the cross former 11, cross former 11 is fixed on the housing of stable cavity 2, honeycomb 6 is located between ground floor and the second layer damping screen 7, honeycomb 6 and damping screen 7 are fixed on the housing of stable cavity 2, contraction chamber 3 is located at the left end of nozzle 10, the left end of nozzle 10 is connected with the housing of contraction chamber 3 right-hand members, and the left end of air flow meter links to each other with the outlet of air intake duct model measurement section.
Embodiment two: describe present embodiment in conjunction with Fig. 1, Fig. 2.The described honeycomb 6 of present embodiment is made up of the hexagonal lattice with certain length-diameter ratio.
Embodiment three: describe present embodiment in conjunction with Fig. 1, Fig. 2.The described honeycomb 6 of present embodiment is a hexagonal lattice, and its length-diameter ratio is 3～4.Best hexagonal lattice length-diameter ratio is 3.75.
Embodiment four: describe present embodiment in conjunction with Fig. 1.The angle of diffusion chamber 1 inner chamber body of present embodiment is 20 °～25 °.
Honeycomb adopts the hexagonal lattice structure, and length-diameter ratio also improves than former flowmeter, to increase rectification effect, improves the air velocity distribution quality in the flowmeter, reaches and improves the purpose of measuring precision.
New flowmeter records flow and measuring section and records the flow contrast in table 1 wind tunnel test
New flowmeter is measured cross section stagnation pressure unevenness situation in table 2 wind tunnel test
Table 3 new flowmeter calibration result in calibrating tank
Seven root mean square precision of table 4 new flowmeter measurement result
Table 5 air intake duct model measurement Duan Yuyuan flowmeter records flow contrast (flowmeter does not add the temperature compensation)
Table 1～table 4 is the results of wind tunnel and the calibrating tank calibration result of flowmeter of the present utility model.
As can be seen, new flowmeter and measuring section compare, and difference is all in 1%.The stagnation pressure unevenness of flowmeter survey section is more much lower than the stagnation pressure unevenness at measuring section place simultaneously.
Indivedual points were slightly high in 0.6% in most o'clock for the measurement result of flowmeter and the measuring result error of calibrating tank; The measuring accuracy of flowmeter and the measuring accuracy of calibrating tank, substantially the same, be in same magnitude.
Claims (5)
1. air flow meter with high precision and large range, it is by diffusion chamber (1), stable cavity (2), contraction chamber (3), adapter cavity (4), center fiaring cone (5), honeycomb (6), damping screen (7), nozzle (10) and cross former (11) are formed, it is characterized in that adapter cavity (4) is located at the left side of cavity, diffusion chamber (1) is located at the right side of adapter cavity (4), stable cavity (2) is located at the right of diffusion chamber (1), center fiaring cone (5) is located on the interior cross former (11) of diffusion chamber (1), center fiaring cone (5) is provided with wire netting, cross former (11) is fixed on the housing of stable cavity (2), honeycomb (6) (is located in the middle of ground floor and the second layer damping screen (7), honeycomb (6) and damping screen (7) are fixed on the housing of stable cavity (2), contraction chamber (3) is located at the left end of nozzle (10), and the left end of nozzle (10) is connected with the housing of contraction chamber (3) right-hand member.
2. a kind of air flow meter with high precision and large range according to claim 1 is characterized in that honeycomb (6) is made up of hexagonal lattice.
3. a kind of air flow meter with high precision and large range according to claim 1, the angle that it is characterized in that diffusion chamber (1) inner chamber body is 20 °～25 °.
4. a kind of air flow meter with high precision and large range according to claim 2, the length-diameter ratio that it is characterized in that the hexagonal lattice of honeycomb (6) is 3～4.
5. according to claim 2 or 4 described a kind of air flow meter with high precision and large range, the hexagonal lattice length-diameter ratio that it is characterized in that honeycomb (6) is 3.75.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009202441342U CN201795822U (en) | 2009-11-20 | 2009-11-20 | High-precision large-scale gas flow meter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009202441342U CN201795822U (en) | 2009-11-20 | 2009-11-20 | High-precision large-scale gas flow meter |
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| CN201795822U true CN201795822U (en) | 2011-04-13 |
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| CN2009202441342U Expired - Fee Related CN201795822U (en) | 2009-11-20 | 2009-11-20 | High-precision large-scale gas flow meter |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104329325A (en) * | 2014-10-22 | 2015-02-04 | 无锡杰尔压缩机有限公司 | Flow stabilizing device for air intake of fan |
| CN104721929A (en) * | 2015-03-24 | 2015-06-24 | 湖南明康中锦医疗科技发展有限公司 | Breathing machine cut-off device |
| CN112197293A (en) * | 2020-09-11 | 2021-01-08 | 北京动力机械研究所 | Heat sink cylindrical rectifier for stable combustion of heater |
| CN112903232A (en) * | 2021-01-22 | 2021-06-04 | 中国空气动力研究与发展中心高速空气动力研究所 | Flow regulating device for wind tunnel test of aircraft atmospheric data system |
| CN113252293A (en) * | 2021-06-08 | 2021-08-13 | 中国空气动力研究与发展中心低速空气动力研究所 | Gas rectification structure inside box body |
-
2009
- 2009-11-20 CN CN2009202441342U patent/CN201795822U/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104329325A (en) * | 2014-10-22 | 2015-02-04 | 无锡杰尔压缩机有限公司 | Flow stabilizing device for air intake of fan |
| CN104721929A (en) * | 2015-03-24 | 2015-06-24 | 湖南明康中锦医疗科技发展有限公司 | Breathing machine cut-off device |
| CN104721929B (en) * | 2015-03-24 | 2016-08-31 | 湖南明康中锦医疗科技发展有限公司 | A kind of respirator cut-off equipment |
| CN112197293A (en) * | 2020-09-11 | 2021-01-08 | 北京动力机械研究所 | Heat sink cylindrical rectifier for stable combustion of heater |
| CN112197293B (en) * | 2020-09-11 | 2022-07-12 | 北京动力机械研究所 | Heat sink cylindrical rectifier for stable combustion of heater |
| CN112903232A (en) * | 2021-01-22 | 2021-06-04 | 中国空气动力研究与发展中心高速空气动力研究所 | Flow regulating device for wind tunnel test of aircraft atmospheric data system |
| CN113252293A (en) * | 2021-06-08 | 2021-08-13 | 中国空气动力研究与发展中心低速空气动力研究所 | Gas rectification structure inside box body |
| CN113252293B (en) * | 2021-06-08 | 2021-10-01 | 中国空气动力研究与发展中心低速空气动力研究所 | Gas rectification structure inside box body |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110413 Termination date: 20111120 |