CN109445476B - Enthalpy difference laboratory nozzle automatic control method - Google Patents
Enthalpy difference laboratory nozzle automatic control method Download PDFInfo
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- CN109445476B CN109445476B CN201811179720.3A CN201811179720A CN109445476B CN 109445476 B CN109445476 B CN 109445476B CN 201811179720 A CN201811179720 A CN 201811179720A CN 109445476 B CN109445476 B CN 109445476B
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- 230000003068 static effect Effects 0.000 claims abstract description 52
- 230000003247 decreasing effect Effects 0.000 claims abstract description 3
- 238000002347 injection Methods 0.000 claims description 6
- 239000007924 injection Substances 0.000 claims description 6
- 238000012360 testing method Methods 0.000 abstract description 11
- 230000002159 abnormal effect Effects 0.000 abstract description 2
- 238000004378 air conditioning Methods 0.000 description 2
- 238000009533 lab test Methods 0.000 description 2
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D16/00—Control of fluid pressure
- G05D16/20—Control of fluid pressure characterised by the use of electric means
Abstract
The invention discloses an enthalpy difference laboratory nozzle automatic control method, which comprises the following steps: detecting the static pressure value of the receiving chamber in real time, and judging whether the static pressure stability judgment condition is met; after the static pressure stability judging condition is met, detecting the wind speed at the nozzle, and judging whether the wind speed stability judging condition is met; after the condition of stable wind speed judgment is met, if the wind speed is greater than the maximum set value, the nozzle investment is sequentially increased, if the wind speed is less than the minimum set value, the nozzle investment is sequentially decreased, and after the nozzle is replaced each time, whether the conditions of stable static pressure judgment and stable wind speed judgment are met is judged again until the wind speed is stabilized between the maximum set value and the minimum set value. The invention can automatically adjust the nozzle according to the air volume requirement of the tested machine without the intervention and operation of personnel, reduces the workload of personnel, improves the working efficiency, and simultaneously sets the alarm reminding to remind the experimenter in time when the test is abnormal.
Description
Technical Field
The invention belongs to the technical field of automatic control, and particularly relates to an enthalpy difference laboratory nozzle automatic control method.
Background
The enthalpy difference laboratory circulating air quantity measuring device is generally composed of a receiving chamber, an exhaust chamber, nozzles and the like, a room air conditioner is connected with the receiving chamber through an air pipe, one or more nozzles are installed on one wall surface of the receiving chamber and exhaust air to the exhaust chamber, the size of the exhaust chamber is required to enable the air speed of a throat nozzle to be not lower than 15m/s, and an exhaust fan is required to be installed in the exhaust chamber to overcome the resistance of the exhaust chamber, the nozzles and a rectifying plate. The number and the size of the nozzles of the measuring devices with different circulating air volumes are different. In the measuring process, different nozzles or nozzle combinations are required to be opened according to the air volume of the tested machine, so that the circulating air volume can be accurately measured.
For example, chinese patent CN201820015201.2 discloses an upper and lower formula enthalpy difference laboratory, including indoor side environment room and outdoor side environment room, indoor side environment room and outdoor side environment room all include air treatment facilities, indoor side environment room and outdoor side environment room still include air sampling device, amount of wind measuring device and data acquisition system, outdoor side environment room sets up in indoor side environment room top, outdoor side environment room top is connected with a hoist and mount subassembly.
Laboratory test personnel need select suitable nozzle according to the machine air volume of being tested, and the machine air volume of being tested under different operating modes or test mode is changed, therefore all the time needs laboratory test personnel to readjust nozzle or nozzle combination.
Disclosure of Invention
The invention aims to provide an automatic control method of an enthalpy difference laboratory nozzle, which can intelligently adjust the nozzle or the combination of the nozzles according to the static pressure condition of a receiving chamber and the wind speed condition at the nozzle and achieve the aim of accurately measuring the wind volume.
In order to achieve the purpose, the invention adopts the following technical scheme: an enthalpy difference laboratory nozzle automatic control method, comprising:
detecting the static pressure value of the receiving chamber in real time, and judging whether a static pressure stability judgment condition is met;
after the static pressure stability judging condition is met, detecting the wind speed at the nozzle, and judging whether the wind speed stability judging condition is met;
after the wind speed stability judging condition is met, if the wind speed is larger than the maximum set value, the nozzle investment is sequentially increased, if the wind speed is smaller than the minimum set value, the nozzle investment is sequentially decreased, and after the nozzle is replaced each time, whether the static pressure stability judging condition and the wind speed stability judging condition are met is judged again until the wind speed is stabilized between the maximum set value and the minimum set value.
Further, the static pressure stability determination needs to satisfy the following two conditions at the same time:
the maximum deviation value of the static pressure of the receiving chamber in the T1 time is less than X1;
the average deviation value of the static pressure of the receiving chamber in the T1 time is less than X2;
wherein T1 is the first interval time, X1 is the first static pressure value, and X2 is the second static pressure value;
the maximum deviation value is equal to the static pressure maximum value-static pressure set value in the T1 time;
average deviation value is static pressure average value-static pressure set value in T1 time.
Further, the condition of meeting the wind speed stability judgment is as follows: deviation of any wind speed measured value and the average value within T2 time is less than X3;
wherein T2 is the second interval time and X1 is the third wind speed value.
Further, the following steps are adopted for increasing the input of the nozzle in sequence:
arranging the sums from small to large by combining all nozzles, each combination having a sum;
when the injection of the nozzle needs to be increased, finding out a sum which is larger than the current sum and is closest to the current sum, and finding out a nozzle combination according to the sum;
the current nozzle combination is turned off first and then the sum nozzle combination is turned on.
Further, the following steps are adopted for sequentially reducing the investment of the nozzles:
arranging the sums from small to large by combining all nozzles, each combination having a sum;
when the injection of the nozzles needs to be reduced, finding out a sum which is smaller than the current sum and is closest to the current sum, and finding out a nozzle combination according to the sum;
the current nozzle combination is turned off first and then the sum nozzle combination is turned on.
Further, when the current nozzle combination is turned off and the new sum nozzle combination is turned on, if there is the same nozzle in both sums, the nozzle does not need to be repeatedly turned on and off.
Further, the nozzle assembly includes more than one nozzle.
Further, the sum of the nozzle combinations is a sum of the combined sum of the input values of all the nozzles, taking the diameter of the nozzle as the input value.
And further, detecting the static pressure value of the receiving chamber in real time, and alarming and reminding if the static pressure stability judgment condition is judged not to be met.
Further, the wind speed at the nozzle is detected, and if the wind speed stability judgment condition is judged not to be met, an alarm is given.
In current amount of wind testing process, the experimenter needs to pay attention to whether nozzle number satisfies the test demand in real time, needs the experimenter to set up again when becoming the operating mode at every turn, and the accuracy of setting up simultaneously has certain requirement to the technical ability of experimenter self. The method can intelligently adjust the nozzle or the nozzle combination according to the static pressure condition of the receiving chamber and the wind speed condition at the nozzle, so as to achieve the aim of accurately measuring the wind volume. The invention can automatically adjust the nozzle according to the air volume requirement of the tested machine without the intervention and operation of personnel, reduces the workload of personnel, improves the working efficiency, and simultaneously sets the alarm reminding to remind the experimenter in time when the test is abnormal.
Drawings
Figure 1 is a flow chart of an embodiment enthalpy difference laboratory nozzle automatic control method.
FIG. 2 is a flowchart of increasing the nozzle input in sequence in the embodiment.
FIG. 3 is a flow chart of sequentially reducing the nozzle input in the embodiment.
Detailed Description
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
1. Definition of
1) Static pressure: the static pressure of the receiving chamber was measured directly by a pressure gauge.
2) And wind speed: the wind speed Vn at the nozzle is calculated by the following formula:
Re＝V∞Dn/v (1)
convergence conditions
Before the convergence condition is satisfied, V∞＝VnAnd replaced and the 1-4 calculations repeated.
Wherein C is the flow coefficient of the nozzle; reIs the Reynolds number; v∞Assuming the flow velocity (m/s) of the nozzle opening, the initial value
VnIs the flow velocity (m/s) of the nozzle opening; dnIs the diameter of the nozzle opening (m); v is the coefficient of dynamics (m)3/s)。
Variables C (nozzle flow coefficient) and Δ P required for determining the wind speed Vn of the nozzle opening in the above formulan(differential pressure before and after nozzle) VnThe (specific air volume) can be calculated from the basic parameters (dry-bulb temperature, wet-bulb temperature, atmospheric pressure) collected in the enthalpy difference laboratory, where ΔPnNozzle dynamic pressure and nozzle static pressure were measured by pressure gauges.
3) And judging stability: whether the current value satisfies the set condition or not.
4) And average deviation value: mean-set value.
5) And the maximum deviation value: maximum-set value.
6) And a set value: according to the requirements of test standards.
2. Stability is judged to static pressure
After the test is started, stability is judged according to the static pressure value acquired in real time and the following conditions are met.
1) The maximum deviation value in any 60 seconds is less than +/-1.5 (Pa);
2) the average deviation value in any 60 seconds is less than +/-0.5 (Pa);
note (1): pa is pascal, pressure units.
Note (2): national standard GB/T7725-2004 Room air Conditioning (Room air Conditioning) requires the static pressure in the receiving chamber to be adjusted to zero, or other standards require the static pressure in the receiving chamber to be adjusted to a set value that allows for a mean deviation of the tolerances of the readings of + -5 (Pa), a maximum deviation of + -10 Pa.
3. Wind speed stability judgment
After the static pressure is judged to be stable, according to the wind speed value at the nozzle, the stability is judged to meet the following conditions:
the mean value within any 2100 seconds of time deviates from the value at the next moment by less than + -0.5 (m/s).
Note that (1) the national standard GB/T7725-2004 Room air conditioner requires that the wind speed value at the nozzle is between 15m/s and 35 m/s;
4. automatic nozzle adjusting method
After the static pressure and the wind speed are judged to be stable, whether the wind speed is between (X (min) and X (max)) or not is detected, and within any 60 seconds:
note (1), the static pressure range and the wind speed range are clearly specified, and the stability judgment range is strict with the test standard. (X (min) to X (max)) is based on a standard but differs from the standard, for example by a standard specification of between 15 and 35, but here less than this range, since a certain margin is required, which may be between 15.1 and 34.9.
A. If the wind speed is in the interval, the nozzle does not act;
B. if the wind speed is not in the interval, the method is executed according to the following 1) and 2);
1) and if the wind speed is less than X (min), gradually reducing the investment of the nozzle according to the following method. After the nozzle is replaced once, the static pressure and the wind speed are required to be judged stably again. The specific method comprises the following steps:
by combining all nozzles, each combination having a sum, the sums are arranged from small to large. When the injection of the nozzles needs to be reduced, finding the sum which is smaller than the current sum and is closest to the current sum, and finding the nozzle combination according to the sum. The current nozzle combination is turned off first and then this sum nozzle combination is turned on. If there is the same nozzle in both sums, then this nozzle need not be repeatedly switched.
Note (1), the nozzle control of the enthalpy difference method laboratory is usually to replace the nozzle by manually clicking a touch screen to trigger the PLC program or clicking test software to trigger the PLC program. The scheme is that a program is written to be communicated with the PLC, whether the nozzle is replaced or not is automatically judged through current data, and manual clicking is not needed.
Note (2), nozzle sum value is based on the nozzle diameter summation, e.g., a nozzle diameter of 70mm is currently used, and the sum value is 70, as follows, FIG. 2.
￠70--------70
￠80--------80
￠70+￠80--------150
2) And if the wind speed is higher than X (max), gradually increasing the nozzle input according to the following method. After the nozzle is replaced once, the static pressure and the wind speed are required to be judged stably again. The specific method comprises the following steps:
by combining all nozzles, each combination having a sum, the sums are arranged from small to large. When the injection of the nozzle needs to be increased, the sum which is larger than the current sum and is closest to the current sum is found, and the nozzle combination is found according to the sum. The current nozzle combination is turned off first and then this sum nozzle combination is turned on. If there is the same nozzle in both sums, then this nozzle need not be repeatedly switched. As shown in fig. 3.
5. Test abnormity warning function
The program has an alarm function according to the static pressure condition at the air supply port of the air conditioner and the air speed condition at the nozzle, and an operator is reminded of what contents need to be checked through the man-machine interaction interface after the alarm occurs.
1) The static pressure at the air supply port of the air conditioner is unstable and alarms;
2) after the nozzle is completely opened or closed, the wind speed still exceeds the range;
example 1
In the existing 3HP enthalpy difference laboratory, a circulating air quantity measuring device is provided with nozzles with three specifications of phi 70, phi 80 and phi 100. The existing air quantity is 500 (m)3The room air conditioner of/h) tests the circulating air volume, opens a phi 80 nozzle according to the measurement range, closes phi 70 and phi 100 nozzles to start the experiment:
1. stability is judged to static pressure
After the test is started, the regulator can regulate the rotating speed of the exhaust fan according to the target value and the current value so as to gradually reach the target value. And (4) judging stability according to the static pressure value acquired in real time and meeting the following conditions.
1) The maximum deviation value in any 60 seconds is less than +/-1.5 (Pa);
2) and the average deviation value in any 60 seconds is less than +/-0.5 (Pa).
2. Wind speed stability judgment
After the static pressure is judged to be stable, according to the wind speed value at the nozzle, the stability is judged to meet the following conditions:
1) and the deviation of the mean value from the value at the next moment in any 2100 seconds is less than +/-0.5 (m/s).
3. Automatic nozzle adjusting method
After the static pressure and the wind speed are judged to be stable, whether the wind speed is between 15 and 35m/s or not is detected, and the following conditions are met within any 60 seconds:
A. if the wind speed is in the interval, the nozzle does not act;
B. if the wind speed is not in the interval, the method is executed according to the following 1) and 2);
1) and if the wind speed is less than 15m/s, reducing the investment of the nozzles according to the sum of the nozzles. The sum of the current nozzles is 70, 80 and 150 from small to large, if the sum which is less than 80 and is closest to 80 is found, the sum is '70', if the nozzle phi 70 is found according to '70', the nozzle phi 80 is closed first, and then the nozzle phi 70 is opened. And after the replacement is finished, the static pressure judgment stability and the wind speed judgment stability are started again, and the process is circulated. Note (2), nozzle sum value is given by summing the nozzle diameters, e.g. a nozzle diameter of 70mm is currently used, and the sum value is 70, as follows:
￠70--------70
￠80--------80
￠70+￠80--------150
2) and if the wind speed is more than 35m/s, increasing the nozzle input according to the nozzle sum value. 70, 80 and 150 are arranged from small to large according to the sum of the current nozzles, the sum which is larger than 80 and is closest to 80 is found to be '150', the nozzle phi 70+ phi 80 is found according to '150', the phi 80 nozzle is opened currently, and the phi 70 nozzle is opened directly. And after the replacement is finished, the static pressure judgment stability and the wind speed judgment stability are started again, and the process is circulated.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. An enthalpy difference laboratory nozzle automatic control method is characterized by comprising the following steps:
detecting the static pressure value of the receiving chamber in real time, and judging whether a static pressure stability judgment condition is met;
after the static pressure stability judging condition is met, detecting the wind speed at the nozzle, and judging whether the wind speed stability judging condition is met;
after the wind speed stability judging condition is met, if the wind speed is greater than the maximum set value, the nozzle investment is sequentially increased, if the wind speed is less than the minimum set value, the nozzle investment is sequentially decreased, and after the nozzle is replaced each time, whether the static pressure stability judging condition and the wind speed stability judging condition are met is judged again until the wind speed is stabilized between the maximum set value and the minimum set value;
the static pressure stability judgment needs to simultaneously meet the following two conditions:
the maximum deviation value of the static pressure of the receiving chamber in the T1 time is less than X1;
the average deviation value of the static pressure of the receiving chamber in the T1 time is less than X2;
wherein T1 is the first interval time, X1 is the first static pressure value, and X2 is the second static pressure value;
the maximum deviation value is equal to the static pressure maximum value-static pressure set value in the T1 time;
the average deviation value is equal to the static pressure average value-static pressure set value in T1 time;
the condition of meeting the wind speed stability judgment is as follows: deviation of any wind speed measured value and the average value within T2 time is less than X3;
wherein T2 is the second interval time and X3 is the third wind speed value.
2. The method of automatic control of enthalpy difference laboratory nozzles according to claim 1, characterized by: the method for increasing the input of the nozzles sequentially comprises the following steps:
arranging the sums from small to large by combining all nozzles, each combination having a sum;
when the injection of the nozzle needs to be increased, finding out a sum which is larger than the current sum and is closest to the current sum, and finding out a nozzle combination according to the sum;
the current nozzle combination is turned off first and then the sum nozzle combination is turned on.
3. The method of automatic control of enthalpy difference laboratory nozzles according to claim 1, characterized by: the method for reducing the investment of the nozzles sequentially comprises the following steps:
arranging the sums from small to large by combining all nozzles, each combination having a sum;
when the injection of the nozzles needs to be reduced, finding out a sum which is smaller than the current sum and is closest to the current sum, and finding out a nozzle combination according to the sum;
the current nozzle combination is turned off first and then the sum nozzle combination is turned on.
4. The enthalpy difference laboratory nozzle automatic control method according to claim 2 or 3, characterized in that: the closing of the current nozzle combination and the opening of the new sum nozzle combination, if there is the same nozzle in both sums, then this nozzle does not need to be repeatedly switched.
5. The enthalpy difference laboratory nozzle automatic control method according to claim 2 or 3, characterized in that: the nozzle assembly includes more than one nozzle.
6. The method of automatic control of enthalpy difference laboratory nozzles according to claim 5, characterized by: the sum of the nozzle combinations is the diameter of the nozzle as the input value, and the sum of all the nozzle input values of the nozzle combinations is the combined sum.
7. The method of automatic control of enthalpy difference laboratory nozzles according to claim 1, characterized by: and detecting the static pressure value of the receiving chamber in real time, and alarming and reminding if the static pressure stability judging condition is not met.
8. The method of automatic control of enthalpy difference laboratory nozzles according to claim 1, characterized by: and detecting the wind speed at the nozzle, and alarming and reminding if the wind speed stability judgment condition is not met.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN202853919U (en) * | 2012-11-12 | 2013-04-03 | 天津市卓东科技发展有限公司 | Enthalpy difference laboratory |
| CN108254207A (en) * | 2018-01-05 | 2018-07-06 | 深圳市英维克科技股份有限公司 | A kind of air-conditioning enthalpy difference performance test room |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| DE2727106A1 (en) * | 1977-06-16 | 1978-12-21 | Wilfried Prof Dr Ing Roetzel | Fluid flow enthalpy difference measurement - involves comparison temp. and temp. measurement before and after tapped flow de-mixing |
| CN2766232Y (en) * | 2004-12-30 | 2006-03-22 | 广州擎天成套装备工程有限公司 | Integrated air-conditioner testing room structure |
| US7367202B2 (en) * | 2005-08-17 | 2008-05-06 | Denso Corporation | Refrigerant cycle device with ejector |
| JP5455999B2 (en) * | 2011-10-11 | 2014-03-26 | スガ試験機株式会社 | Weather resistance tester |
| CN102539108B (en) * | 2012-01-06 | 2014-07-23 | 合肥通用机械研究院 | Energy-saving wind tunnel for enthalpy potential method experiment device |
| CN102589918A (en) * | 2012-02-28 | 2012-07-18 | 上海市计量测试技术研究院 | Method for correcting full performance of air enthalpy tester for test |
| CN102967478A (en) * | 2012-11-12 | 2013-03-13 | 天津市卓东科技发展有限公司 | Enthalpy difference laboratory |
| CN203798820U (en) * | 2013-12-24 | 2014-08-27 | 格力电器（合肥）有限公司 | Sampling wind speed monitoring device and enthalpy potential method experiment detection equipment having same |
| CN105202792B (en) * | 2015-10-15 | 2018-02-16 | 珠海格力电器股份有限公司 | Air injection enthalpy-increasing system, the air-conditioner set and the increasing enthalpy control method with the system |
| CN105806588A (en) * | 2016-04-12 | 2016-07-27 | 合肥通用机械研究院 | Enthalpy difference method test system containing nozzle sealing mechanism |
| CN108469198A (en) * | 2018-03-21 | 2018-08-31 | 深圳市英维克科技股份有限公司 | A kind of energy-saving enthalpy difference laboratory |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202853919U (en) * | 2012-11-12 | 2013-04-03 | 天津市卓东科技发展有限公司 | Enthalpy difference laboratory |
| CN108254207A (en) * | 2018-01-05 | 2018-07-06 | 深圳市英维克科技股份有限公司 | A kind of air-conditioning enthalpy difference performance test room |
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