JPH07117433B2 - Air flow measurement method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air volume measuring method for measuring the volume of air blown or taken in by an opening such as an air outlet or an inlet of an air conditioning equipment.

[Conventional technology]

When air conditioning of each room in an office building and other buildings, among the air conditioning equipment, the air conditioning equipment consisting of a refrigerator, a blower, a boiler, a pump, and other auxiliary equipment is put together in a machine room such as a basement. After adjusting the temperature and humidity of the air sent to each room with this air conditioner, this is distributed and blown to each room through the main duct, and the air in each room is returned to the machine room side through the return duct. It is like this. Particularly, on the air conditioning chamber side, as shown in FIG. 8, a branch duct 2 branched from a main duct 1 of one air conditioning system is connected to a plurality of outlets 4 arranged in a chamber 3,
Conditioned air is blown into the chamber 3 from each of the air outlets 4. A branch duct 6 branched from the return duct 5 of one air conditioning system is connected to the suction ports 7 arranged in the chamber 3, and the indoor air is sucked from each of the suction ports 7, thereby maintaining the room at a predetermined pressure. At the same time, the room is designed to have a predetermined ventilation frequency. However, since the pressure loss of the duct and the pressure loss of the blowout port or the suction port cannot be clearly set at the time of design, the main damper 8 provided at the connecting portion of the branch duct 2 with the main duct 1 and the blowout ports 4 are provided in each blowout port 4. The proper air volume is ensured by adjusting the damper 9 or the main damper 10 provided at the connecting portion of the branch duct 6 to the return duct 5 and the damper 11 provided in each of the blowing ports 7.

Further, as an example of the air outlets applied to the central type air conditioning equipment as described above, it has the structure shown in FIG. 9 and FIG. That is, the conditioned air sent through the duct 2 passes through the damper 9, bends at 90 ° at the upper part of the outlet 4, and is blown out into the room through the diffusion fins 4a arranged at the opening of the outlet 4.

In this way, there are many obstacles in the air passage to the outlet 4, and since the fins 4a are arranged in the opening of the outlet 4, there is a difference in the amount of air blown from between the fins 4a. Yes, and because the flow direction of the blown air is also different, even if the wind speed blown out between the fins 4a is directly measured, it is necessary to obtain the true air volume blown out from the effective opening of the blowout port 4 from the measured wind speed value. I can't.

Therefore, a method is usually adopted in which a blow-out air collector such as a cylinder is attached to the blow-out port, the air flow from the blow-out port is kept constant by this, the wind speed is measured, and the blow-out air volume is determined from this wind speed. There is. This is the same in the case of the blow port.

The first method of actual air volume measurement by the above method is
As shown in FIG. 11, the large cross-sectional area base 12a of the air collecting body 12 for collecting the blown air is set so as to cover the blow-out port 4 (or the suction port), and the throttle tube portion 12 having the small cross-sectional area is set.
The blower fan 13 is attached to the tip opening of b, and the sensor portion 15a of the anemometer 15 is inserted into the wind velocity measuring port 14 formed on the tip side surface of the throttle cylinder portion 12b. In this state, the fan 13 while watching the pressure gauge 16 so that the pressure at the insertion position of the sensor portion 15a becomes atmospheric pressure.
Adjust the number of revolutions of and measure the wind speed at atmospheric pressure with an anemometer 15. The air velocity is calculated by multiplying the obtained wind velocity by the cross-sectional area of the throttle tube portion 12b at the portion where the sensor portion 15a is attached.

As a second method, as shown in FIGS. 12 (a) and 12 (b), a rectangular tube-shaped blowout air collector formed into an external dimension that surrounds the outer periphery of the blowout port 4 (or suction port). One end opening of 17 is attached to the air outlet 4, a plurality of measurement points 18 are set on the other end opening side (or intermediate part) in the air collector 17, and the sensor part 15a of the anemometer 15 is set to each measurement point 18. The wind speed is set and measured, the wind speeds obtained at the respective measurement points are averaged, and the average wind speed is multiplied by the square tube cross-sectional area of the measurement site to calculate the air volume.

As another method, the pressure adjusting fan of the first method is used.
There are a simple method not using 13 and a method of measuring the air volume by removing the fin 4a of the air outlet 4.

[Problems to be Solved by the Invention]

In the conventional air volume measuring method as described above, in the first method, the pressure at the measurement site is set to the atmospheric pressure, so that a value close to the true wind speed can be obtained. If there is a fluctuation in the amount of blown air or suction air of the machine, the pressure at the measurement site will fluctuate, so it is very difficult to maintain the pressure at atmospheric pressure, and the air collector described above for each blowout port or suction port, It takes time to measure the wind speed by setting the fan, anemometer and pressure gauge. In addition, since there are many measuring instruments, pressure gauges, anemometers, air collectors for measurement, etc. must be transported to the measurement location for each one of the air outlets or the air inlets, which requires a lot of manpower and workers. There was a problem.

Also, in the second method, the air collector of the wind velocity measuring unit
Since the cross-sectional area of 16 is almost the same as the opening area of the outlet (or inlet), it is necessary to measure and average the wind speed at multiple points on the same plane, but it is necessary to consider the pressure fluctuation. Since there is no pressure adjustment work, it is unnecessary. However, regardless of the same outlet or inlet, the air collector 17 must be attached to each outlet or inlet to measure the wind speed, which requires a lot of manpower and time to measure the wind speed. However, there has been a problem that the measurement work becomes complicated and the accuracy of the wind speed measurement is impaired.

The present invention solves the above-mentioned problems and eliminates the need to attach an air collector to each of the air outlets or the air inlets to measure the wind speed, thereby shortening the measurement time and reducing the number of personnel. It is an object of the present invention to provide an air volume measuring method that enables reliable air volume measurement at low cost.

[Means for Solving the Problems]

The air volume measuring method according to the present invention, the average wind speed in the cross section by measuring the wind speed at a plurality of locations in the cross section of the air collection body in the state that the air collection body that adjusts the wind direction is set at the air outlet or the suction port. Then, the first air volume is calculated by multiplying the average wind speed by the cross-sectional area of the measurement site of the air collector, and then the wind speeds at the same outlet or at multiple inlets with the air collector removed. The average wind speed at all measurement points is obtained by directly measuring with an anemometer, the second wind volume is calculated by multiplying the average wind speed by the area of the air outlet or suction port, and the first air volume is calculated as the second air volume.
It is possible to measure the air flow rate by dividing the air flow rate obtained directly from this by multiplying the air flow rate obtained directly from the air flow rate of the air outlet or suction port by dividing by the air flow rate of It is a thing.

[Work]

In the present invention, the air volume in the state where the air collector is set to the air outlet or the suction port, and the air volume of the same air outlet or the air inlet with the air collector removed, to determine the effective opening area ratio of the air outlet or the air inlet. For air outlets or suction ports of the same shape that have been obtained in advance, the air volume of the air outlet or suction port can be measured simply by multiplying the air volume directly obtained from this by the previously obtained aperture ratio. An air collector is not required for measuring the air volume at the air outlet or the air inlet of the air conditioner, which enables labor saving and cost reduction of the air volume measurement.

〔Example〕

Hereinafter, embodiments of the method of the present invention will be described in detail with reference to the drawings.

When measuring the air volume of the outlet, as shown in FIG. 1 (a), the upper end opening of a square tubular outlet air collector 20 having a cross-sectional shape slightly larger than the outer dimensions of the outlet 4 is used as the outlet. 4 is engaged so as to surround it, and this state is held by the worker 21. Then, the lower end opening 20a of the air collecting body 20
On the (air outflow side) side, the part parallel to the outlet 4 where the wind direction is aligned is the wind speed measurement level 22.
As shown in FIG. 1 (b), a plurality of wind speed measurement points 23 ₁ to 23 _n are set in the transverse plane of the air collector 20 including 22 and other workers 24 are set at the respective measurement points 23 ₁ to 23 _n. Set the sensor part 25a of the hot-wire anemometer 25 carried by the user to set the wind speeds a _{1 to} a at the measurement points 23 ₁ to 23 _n.
Measure _n sequentially. The wind speed data a _{1 to} a _n for each measurement point measured by the anemometer 25 are calculated by the arithmetic unit connected to the anemometer 25.
Sequentially taken in 26, calculate the average wind speed A at all measurement points. After that, the keyboard 27 provided in the arithmetic unit 26 is operated to input the opening cross-sectional area b of the air collecting body 20 into the arithmetic unit 26, and the average wind speed A is multiplied to the cross-sectional area b to calculate the air volume X.

Next, after removing the air collector 20 from the outlet 4, the second
As shown in the figure, the worker 24 carries the sensor 25 of the anemometer 25
A is set to the air blowing portion between the fins 4a of the air outlet 4 and the wind speed is measured by the anemometer 25.

In this case, the measurement point for the outlet 4 is not limited to one,
As in the case shown in FIG. 1 (b), there are a plurality of locations.

Measurement wind speed data c ₁ to c _n of the measurement points in the outlet 4 is sequentially read in the arithmetic unit 26 calculates the average wind speed C of all the measurement points. Then, by operating the keyboard 27, the area d of the air outlet 4 is input to the arithmetic unit 26 and multiplied by the average wind speed C to obtain the air volume Y.

Next, the air volume X when the air collector 20 is used is divided by the air volume Y of the air outlet 4 to obtain the ratio k. This ratio k becomes the actual opening ratio of the air outlet 4.

When measuring the air volume of the air outlet having the same shape as that of the air outlet 4 and the same area, the sensor units are provided at a plurality of measurement points set in the air outlet in the same manner as the case described in FIG. sequentially sets 25a wind speed _{c '1 ~c' n} for each measurement point
Is sequentially measured, and the obtained wind velocities c ′ _{1 to} c ′ _n are calculated.
After taking in 26 and adding up, divide by each number of measurement points to obtain the average wind speed c'at the outlet. After that, the obtained average wind speed c ′ is multiplied by the area d of the outlet used for obtaining the ratio and the previously obtained aperture ratio k, and the arithmetic unit 26 executes the calculation of c ′ × d × k = Z. , The air volume Z at the outlet is calculated.

On the other hand, when measuring the air volume of the air outlet when the air outlet 4 has the same shape but a different area, the area d ″ of the air outlet is measured by the same method as the area measuring method of the area d used for obtaining the ratio.
In advance. Then, in the same manner as described above, the wind velocities c ″ _{1 to} c ″ _n at the respective measurement points are sequentially measured to obtain the average wind velocity c ″,
The average wind speed c ″ and the area d ″ of this outlet determined in advance,
The opening ratio k is multiplied and the calculation of c ″ × d ″ × k = Z ″ is executed by the calculation device 26 to calculate the air volume Z at the outlet.

FIG. 3 is a process diagram in which the procedure of the above-described method for measuring the air volume at the outlet is shown in blocks.

In this embodiment as described above, the air collector is provided at the outlet.
Set 20 and adjust the wind direction of the air blown from the outlet, measure the wind speeds at multiple locations in the cross section parallel to the outlet 4, and measure the average wind speed A obtained from these multiple measurement points and the air collection. The air volume X is obtained from the cross-sectional area b of the measurement site of the body 20, and thereafter the air volume of the air outlet 4 is obtained from the average air velocity C of the same outlet 4 with the air collector 20 removed and its area d. ,
Based on the ratio X / Y = k (the opening ratio of the outlet) of the two air amounts, the air amounts of the other outlets of the same shape are calculated. Therefore, when measuring the air volume of the outlets of the same shape, It is only necessary to set the air collector 20 to one of the outlets and measure the air volume, and for the other outlets, use the anemometer 25 and the arithmetic unit 26 to obtain the average wind speed, and blow it to this. The air volumes of the other air outlets can be measured only by multiplying the cross-sectional area of the air outlet 4 and the opening ratio k obtained in advance. Along with this, the air volume can be measured by attaching air collectors to all the air outlets as in the conventional case. Since there is no need to measure, the measurement of the air volume at the outlet becomes simple, the time required for measurement can be greatly shortened, and workability can be improved. Moreover, since the air flow rate can be measured by one worker except when the aperture ratio k is obtained, it is possible to easily realize the labor saving and cost reduction of the air flow rate measurement.

FIGS. 4 and 5 show an embodiment of a sensor support mechanism for stably positioning and supporting the sensor unit at a fixed position at each measurement point of the outlet, and FIG. FIG. 5 and FIG. 5 are front views thereof.

In the figure, one end of the positioning metal fittings 31a, 31b is vertically fixed to the sensor portion 25a attached to the tip of the sensor support rod 30 and the other end is horizontally extended, and the outlet 4 is provided at the tip. Hooks 32a, 32b engaged with the fins 4a of
Is formed.

Therefore, when the sensor portion 25a is set at the measurement point of the outlet 4 when measuring the wind speed of the outlet 4, the positioning fittings 31a, 31
If the hook portions 32a, 32b of b are engaged with the edges of the fin 4a and the entire sensor portion 25a is pressed against the flat portion of the fin 4a in this state, the sensor portion 25a is stably fixed to the fin 4a. It can be set, and accordingly, the sensor unit 25a is not swung to disturb the blown air flow, and accurate wind speed measurement is possible.

6 and 7 show another embodiment of the sensor support mechanism for the air outlet, and FIG. 6 is a cross-sectional plan view of the main part,
FIG. 7 is a front view thereof.

In the figure, at the tip of the sensor support rod 30, a sheath pipe 33 into which the sensor portion 25a is inserted is provided, and upper and lower parts of this sheath pipe 33 are
Set rods 34a, 34b of desired length extending horizontally
Is drilled.

The sensor unit 25a is connected to the air outlet 4 by using the support mechanism having the above configuration.
When setting the sensor point 25a in the sheath tube 33, the set rods 34a and 34b are pressed against the front edge between the adjacent fins 4a and 4a. As a result, the sensor portion 25a including the sheath tube 33 is stably positioned and held in the airflow between the fins 4a, 4a.

In this embodiment, the same effect as the above embodiment can be obtained.

In the above embodiment, only the measurement of the air volume at the air outlet has been described, but it goes without saying that it can be applied to the measurement of the air volume at the suction port.

〔The invention's effect〕

As described above, according to the method of the present invention, the average wind speed is obtained by measuring a plurality of wind speeds in the cross section of the air collecting body in a state where the air collecting body that adjusts the wind direction at the air outlet or the suction opening is set, Calculate the air volume by multiplying this average wind speed by the cross-sectional area of the measurement site, and then calculate the average wind speed by measuring the wind speed at multiple locations of the same outlet or suction port with the air collector removed with an anemometer. , The average air velocity is multiplied by the area of the air outlet or the air inlet to obtain the air volume, and the air volume by the air collector is divided by this air volume to obtain the opening ratio of the air outlet or the air inlet, and thereafter, the air blow of the same shape is performed. For the outlet or the suction port, the air volume is calculated by multiplying the measured wind speed and area by the opening ratio.Therefore, an air collector is not required to measure the air volume of the same-shaped outlet or suction port. , With this, air flow measurement It is simpler, the time required for measurement can be shortened, the workability is improved, and the air volume can be measured by one worker except when the aperture ratio is required. And, there is an effect that the cost can be reduced.

[Brief description of drawings]

FIG. 1 (a) is a schematic configuration diagram of an air volume measuring means using an air collector at the air outlet or the air inlet according to the air volume measuring method of the present invention. FIG. 1 (b) is an explanatory view showing the wind speed measurement points in FIG. 1 (a). FIG. 2 is a schematic configuration diagram of the air volume measuring means of the air outlet or the air inlet according to the method of the present invention. FIG. 3 is a process diagram showing the flow rate measurement procedure in blocks in the embodiment of the method of the present invention. FIG. 4 is a cross-sectional plan view of essential parts showing an embodiment of a sensor support mechanism for an outlet (or an inlet) of a wind speed sensor according to the present invention. FIG. 5 is a front view of FIG. FIG. 6 is a cross-sectional plan view of essential parts showing another embodiment of the sensor support mechanism according to the present invention. FIG. 7 is a front view of FIG. FIG. 8 is a system diagram showing the relationship between the duct of the air conditioning equipment and the air outlet and the air inlet. FIG. 9 is a schematic sectional view showing the connection relationship between the outlet and the duct. FIG. 10 is a front view of the air outlet. FIG. 11 is a schematic configuration diagram of a conventional air outlet flow rate measuring means. FIG. 12 (a) is a schematic configuration diagram showing another example of the conventional air outlet flow rate measuring means. FIG. 12 (b) is an explanatory view showing the wind speed measurement points in FIG. 12 (a). [Description of Reference Numerals major parts] 4 ...... outlet 4a ...... fin 20 ...... air collecting body 22 ...... wind velocity measuring levels 23 ₁ ~ 23 _n ...... measurement points 25 ...... anemometers 25a ...... sensor unit 26 …… Calculator 27 …… Keyboard.

Claims (1)

[Claims] 1. An average wind speed in a cross section is obtained by measuring wind speeds at a plurality of locations in a cross section of the air collection body with an air collection body that adjusts the wind direction at the blowout port or the suction port is set. The first wind volume is calculated by multiplying the average wind speed by the cross-sectional area of the measurement site of the air collecting body, and then the wind speeds at the same outlet or at multiple intake ports with the air collecting body removed are measured by an anemometer. To obtain the average wind speed at all measurement points,
The second air volume is calculated by multiplying the average air speed by the area of the air outlet or the air inlet, and the first air volume is divided by the second air volume to obtain the opening ratio of the air outlet or the air inlet. An air volume measuring method characterized in that the air volume can be measured by multiplying the air volume directly obtained from the air outlet or the suction port by the opening ratio.