JP4911351B2 - Connection structure between flexible duct and air flow control device - Google Patents

Description

  The present invention relates to a connection structure between a flexible duct and an air volume adjusting device when a flexible duct having a bent portion is connected upstream of an air volume adjusting device that adjusts an air supply amount corresponding to an increase or decrease of a thermal load of an air conditioning target space. About.

  In an air conditioning system that adjusts the supply air volume in response to an increase or decrease in the heat load of the air conditioning target space, the speed of the air flowing in from the duct is measured by a wind speed sensor, and the measured air volume becomes the target air volume by comparison with the target inflow air speed. An air volume adjusting device that controls the opening area of a damper provided downstream of the wind speed sensor is used. However, the duct is bent from the central air conditioner to the air-conditioning target space, and particularly when a bent portion is present immediately before the air volume adjusting device, air drift occurs, and the air flow of the air volume control device In the wind speed sensor provided at the center of the cross section of the road, there is a problem that the average wind speed of the ventilation path cannot be detected and the air volume adjustment accuracy is lowered.

In view of this, several inventions have been made to improve the air volume adjustment system by eliminating the influence of this drift and reducing the measurement error.
For example, in JP-A-62-162846, a multi-blade damper is provided on the downstream side of the bent portion of the air supply path having a bent portion, and the upstream side of the multi-blade damper and the downstream side of the bent portion. A wind speed sensor is provided at substantially the center of the cross section of the air supply path, receives the output signal of the wind speed sensor and a target signal representing the target inflow wind speed, compares the output signal with the target signal, and compares the output signal with the target signal. In the air volume control device provided with the adjusting device for adjusting the inflow air speed to the target inflow air speed by controlling the opening degree of the air, the outer shape of the air supply path portion including the wind speed sensor and the multi-blade damper is substantially bell mouth shape An air volume control device is disclosed.

  Japanese Patent Application Laid-Open No. 60-194248 discloses a wind speed sensor at a substantially central portion on the upstream side in the case and a multi-blade damper on the downstream side, and the output signal and target of the wind speed sensor are set in the adjustment device. A target signal representing an average inflow wind speed is input, the two signals are compared, a control signal for the multi-blade damper is output from the adjusting device, and an air volume control device for controlling the inflow air volume is obtained. It is provided in a substantially central part on the upstream side of the wind speed sensor, and is composed of a truncated cone-shaped ring at the tip from upstream to downstream, and a stopper that controls the tilt angle of the ring so that it does not exceed a certain level. An air volume control device is disclosed that includes a turning device that rotates according to a wind speed distribution in which the ring is biased to flow an airflow of an average wind speed toward a wind speed sensor.

Further, Japanese Patent Laid-Open No. 2006-194572 has “a wind speed sensor for detecting the wind speed in the casing of the air volume unit, an opening / closing blade for opening / closing the inside of the casing around the shaft, and an opening / closing device for driving the opening / closing blade. Airflow correction means is provided on the upstream side of the sensor, the airflow correction means is an airflow correction body that primarily corrects the swirling flow generated in the duct in the casing axial direction, and a donut-shaped drift that corrects the drift generated in the duct. An air volume unit that is made of a corrector and supplies the corrected airflow to a downstream wind speed sensor is disclosed.
Japanese Patent Laid-Open No. 62-162846 JP 60-194248 A JP 2006-194572 A

Ducts that have been used in conventional air conditioning systems are rectangular ducts or circular ducts made of steel, and it is necessary to connect the ducts every time they are bent, shortening the construction period and thus reducing construction costs There was a problem that it was difficult to plan. Therefore, in order to shorten the construction period of the air conditioning system and to reduce the construction cost, flexible ducts that are easily bent have been introduced.
However, unlike the wind speed distribution in the spiral duct having a smooth inner wall surface shown in FIG. 3 (b), the wind speed distribution in the flexible duct having unevenness on the inner wall surface has a large resistance on the inner wall surface. As shown in a), the wind speed difference is large between the peripheral portion and the central portion. In addition, if the flexible duct meanders or the bending radius is not constant, the wind speed distribution in the duct will change greatly, making it impossible to predict.
Therefore, when this flexible duct is connected to the air flow rate adjusting device, the air speed measured by the wind speed sensor changes greatly even if the flow of air flowing into the wind speed sensor is slightly deviated by meandering or bending of the flexible duct. If the bent portion of the flexible duct is connected immediately before, the air volume becomes insufficient or excessive with respect to the predetermined upper and lower airflow limits, and stable air conditioning cannot be performed.
The air volume control device and the air volume unit of the above invention that corrects the air flow unevenness and guides the air flow of the average wind speed to the wind speed sensor are also intended to connect a duct with a smooth inner wall upstream from the drawing of the specification. Therefore, it cannot be said that the connection of the flexible duct having the unevenness on the inner wall is considered, and the invention and the device of the air volume adjusting device adapted to the bent flexible duct are not seen.
Therefore, when the flexible duct is connected to the air flow adjusting device, the bent portion of the flexible duct 1 has so far been provided with a straight portion about twice the inner diameter D of the duct upstream of the air flow adjusting device as shown in FIG. Or connected through a short pipe 4 having a length about twice the inner diameter D of the duct. However, this length 2D is the length from the wind speed sensor 2a to the bent portion, which is required when the conventional duct is connected to the air volume adjusting device 2 constituted by the wind speed sensor 2a and the damper 2b. In order to provide an air conditioning system that can stably supply an appropriate air volume, the inner diameter D of the flexible duct 5 between the bent portion and the wind speed sensor 2a is used. It is necessary to provide about twice as many straight portions, which causes a problem when a duct is provided in a limited space.

  In the present invention, in view of the problems of the background art described above, when a flexible duct is connected to an air volume adjusting device including an air speed sensor and an air volume control damper, the distance between the bent portion of the flexible duct and the air speed sensor is the same as that in the past. Even if it is shortened to 2D, it is possible to correct the biased air flow by the bent part, to reduce the fluctuation of the measured value of the wind speed sensor and to perform stable air conditioning, and to solve the problems in duct construction. Provided is a connection structure between a flexible duct and an air volume adjusting device.

The present inventors have solved the above problems by the following means as a result of intensive experimental research.
(1) In a connection structure in which a flexible duct having a bent portion is connected upstream of an air volume adjusting device that adjusts an air supply amount in response to a change in heat load of an air-conditioning target space.
A reducer and a short pipe are provided in this order between the flexible duct and the air volume adjusting device, and the airflow generated at the bent portion of the flexible duct is corrected by the reducer and the short pipe. by supplying air flow to the air velocity sensor disposed at the center of the adjusting device in a commutation state to suppress the measurement error of the air velocity sensor, Ri greens and can be supplied to the air conditioning target space air supply amount required stable,
The reducer is formed with an inner diameter difference of 40 to 60 mm between the openings at both ends and an inclination angle of 8 to 15 degrees, and the length of the short pipe connected to the reducer is equal to or less than the inner diameter D of the flexible duct. A connection structure between a flexible duct and an air flow adjusting device.

(2) In a connection structure in which a flexible duct having a bent portion is connected upstream of an air volume adjusting device that adjusts an air supply amount in response to a change in a thermal load of an air conditioning target space.
Between the flexible duct and the air volume adjusting device, a short pipe with a ring-shaped orifice plate is provided inside the vicinity of the connection end to the air volume adjusting device,
By correcting the bias of the air flow generated at the bent portion of the flexible duct with a short pipe provided with the ring-shaped orifice plate, the air flow is forcibly supplied to a wind speed sensor disposed in the center of the air volume adjusting device. suppressing the measurement error of the air velocity sensor, Ri greens and can be supplied to the air conditioning target space air supply amount required stable, short tube having a pre-Symbol annular orifice plate, equal to the inner diameter D of the flexible duct An orifice plate having an inner diameter and twice the inner diameter and having an inner diameter of 40 to 60 mm smaller than the inner diameter of the short pipe is provided in the pipe at a position of 0 to 100 mm from the connection end of the air flow adjusting device of the short pipe. A connection structure between a flexible duct and an air flow adjusting device characterized by being a thing.

< 1 > In a connection structure in which a flexible duct having a bent portion is connected upstream of an air volume adjusting device that adjusts an air supply amount in response to a change in a heat load of a space to be air-conditioned,
A reducer and a short pipe are provided in this order between the flexible duct and the air volume adjusting device, and the airflow generated at the bent portion of the flexible duct is corrected by the reducer and the short pipe. Since the airflow rectified to almost the same state as the wind speed distribution of the conventional spiral duct is supplied to the wind speed sensor located at the center of the adjusting device, measurement errors of the wind speed sensor are suppressed and the required air supply is stabilized. Can be supplied to the air-conditioned space.
< 2 > A reducer having an inclination angle of 8 to 15 degrees between a flexible duct having an inner diameter D and an air volume adjusting device having an opening having an inner diameter 40 to 60 mm smaller than the inner diameter D of the flexible duct, and a flexible duct having a length A wind speed sensor disposed in the center of the air volume adjusting device, in which a short pipe having an inner diameter D or less is interposed in order, and the bias of the air flow generated at the bent portion of the flexible duct is corrected by the reducer and the short pipe. The air flow that has been rectified into the air flow is suppressed to suppress fluctuations in the measured value of the wind speed sensor, and the required air supply volume can be stably supplied to the air-conditioning target space. The straight part between the bent part and the wind speed sensor, which required 5D or more, can be shortened to 2.5D or less, contributing to the spread of air conditioning systems using flexible ducts. The shortening of the construction work period of the air-conditioning system, cost reduction can be achieved.

< 3 > In a connection structure in which a flexible duct having a bent portion is connected upstream of an air volume adjusting device that adjusts an air supply amount in response to fluctuations in the heat load of the air conditioning target space.
Between the flexible duct and the air flow adjusting device, a short pipe having a ring-shaped orifice plate is provided inside the vicinity of the connection end to the air flow adjusting device, and is generated at the bent portion of the flexible duct. The airflow bias is corrected by the short pipe provided with the ring-shaped orifice plate, and the airflow is forcibly supplied to the wind speed sensor arranged at the center of the air volume adjusting device, so that the measurement error of the wind speed sensor is suppressed. The required air supply amount can be stably supplied to the air-conditioning target space.
< 4 > A ring-shaped orifice plate having an inner diameter 40 to 60 mm smaller than the inner diameter D of the flexible duct is provided between the flexible duct having the inner diameter D and the air volume adjusting device having the same inner diameter of the opening from the connection end of the air volume adjusting device. A short pipe provided with a ring-shaped orifice plate having a length twice as large as the inner diameter D of the flexible duct provided at a position of ˜100 mm is interposed, and the deviation of the air flow generated at the bent portion of the flexible duct is Corrected by a short pipe with a ring-shaped orifice plate, forcibly supplying an air flow to the wind speed sensor disposed in the center of the air volume control device to suppress measurement value error of the wind speed sensor, and to provide the required air supply Since the amount can be stably supplied to the air-conditioning space, the bent portion and the wind speed sensor which have been required to be 5D or more to correct the airflow generated by the bent portion of the conventional flexible duct. Can be shortened interval linear portion of up to about 2D, it can contribute to the spread of air conditioning systems that use flexible duct, shortening of construction work period of the air conditioning system, cost reduction can be achieved.

The embodiment of the connection structure between the flexible duct and the air volume adjusting device of the present invention will be described based on the drawings of the examples.
FIG. 1 is an explanatory diagram of a connection structure between a flexible duct and an air flow adjusting device, which are configured by sequentially placing a reducer and a short pipe between the flexible duct and the air flow adjusting device. FIG. It is explanatory drawing of the connection structure of the flexible duct comprised by interposing the short pipe | tube which provided the ring-shaped orifice board in the inside, and an air volume adjusting device.
In the figure, 1 is a flexible duct, 2 is an air volume adjusting device, 2a wind speed sensor, 2b damper, 3 is a reducer, 4 is a short pipe, 5 is a short pipe provided with an orifice plate inside, 5a is an orifice plate, and D is a flexible duct. The inner diameter is shown.

In the embodiment shown in FIG. 1, a reducer 3 having a length of 150 mm and a short tube 4 having a length of 300 mm are sequentially placed between a flexible duct 1 having an inner diameter D of 300 mm and an air volume adjusting device 2 having an inner diameter of 250 mm. By interposing, the deviation of the air flow generated at the bent portion of the flexible duct 1 is corrected, the rectified air flow is supplied to the wind speed sensor 2a disposed at the center of the air volume adjusting device 2, and the necessary air supply is supplied. The air volume can be stably supplied to the space to be air-conditioned. In this case, the angle of inclination of the reducer is less than 10 degrees.
The total length of the reducer 3 and the short pipe 4 that are straight portions upstream of the wind speed sensor 2a of the present embodiment is 450 mm, and the airflow that is biased at the bent portion of the conventional flexible duct 1 is corrected and added to the wind speed sensor 2a. In this example, a straight portion having a length more than 5 times the inner diameter D of the flexible duct 1 is required upstream of the wind speed sensor 2a, and is shortened to 1.5D.
The inner diameter D of the flexible duct 1 actually used in the air conditioning system is generally manufactured at intervals of 50 mm from 150 mm to 400 mm, and the reducer is provided between the flexible duct 1 and the air volume adjusting device 2 as in this embodiment. In the connection structure of the flexible duct 1 and the air volume adjusting device 2 in which the short pipe 4 is inserted and connected, the flexible duct 1 having the inner diameter D and the air volume adjusting device in which the inner diameter of the opening is 50 mm smaller than the inner diameter D of the flexible duct 1. A combination with 2 is preferred. Moreover, since the angle of inclination of the reducer 3 inserted between the flexible duct 1 and the air volume adjusting device 2 is preferably 8 to 15 degrees, the length of the reducer 3 is 93 to 178 mm and the inner diameter D of the flexible duct 1 is 150 mm. Even in this case, the total length of the reducer 3 and the short pipe 4 which are the straight portions upstream of the wind speed sensor 2a is 328 mm at the maximum, which is significantly shorter than the conventionally required 5D = 750 mm and is 2.2 D or less.
Even when the inner diameter difference between the openings at both ends of the reducer 3 is 60 mm, the maximum length of the reducer 3 is 214 mm at an inclination angle of 8 degrees, and even in the case of the flexible duct 1 with an inner diameter D of 150 mm, the reducer 3. And the total length of the short pipe 4 are reduced to 364 mm and 2.5 D or less.
Furthermore, since the degree of airflow bias differs depending on the bending angle of the bent portion of the flexible duct 1, the length of the short pipe 4 need not always be the same as the inner diameter D of the flexible duct 1, and can be made shorter.
Furthermore, there may be a case where the short pipe 4 is not required. In this case, the straight portion upstream of the wind speed sensor 2a is only the length of the reducer 3, and the inner diameter difference between the openings at both ends of the reducer 3 is large. In the case of 50 mm, 93 to 178 mm, and even in the case of an inner diameter difference of 60 mm, it is 214 mm or less, which is greatly shortened.
Therefore, the straight line portion upstream of the wind speed sensor 2a that requires a length five times the inner diameter D of the conventional flexible duct 1 can be reduced to 2.5 times or less.

In the embodiment shown in FIG. 2, a short pipe 5 having a ring-shaped orifice plate provided inside is interposed between a flexible duct 1 having an inner diameter D of 300 mm and an air volume adjusting device 2 having an opening having the same inner diameter of 300 mm. Then, the bias of the air flow generated at the bent portion of the flexible duct is corrected by the short pipe 5 provided with the ring-shaped orifice plate on the inner side, and is forced to the wind speed sensor 2a disposed in the air volume adjusting device 2. The air flow is supplied to suppress the measurement error of the wind speed sensor 2a, and the necessary air supply amount can be stably supplied to the air-conditioning target space.
In this embodiment, the straight portion having a length of 5D required upstream of the wind speed sensor 2a is shortened to 2D by using the short tube 5 provided with the ring-shaped orifice plate 5a on the inside. .
The inner shape of the ring-shaped orifice plate 5a is preferably 40 to 60 mm smaller than the inner diameter D of the flexible duct 1, and is preferably provided at a position of 0 to 100 mm from the connection end of the air flow adjusting device of the short tube 5.
Therefore, the linear portion upstream of the wind speed sensor 2a, which requires a length five times the inner diameter D of the conventional flexible duct 1, can be reduced to twice or less by the present embodiment.

Explanatory drawing of the connection structure of the flexible duct and airflow adjustment apparatus which comprised the reducer and the short pipe in order between the flexible duct and the airflow adjustment apparatus. Explanatory drawing of the connection structure of the flexible duct and airflow adjustment apparatus which comprised the short pipe which provided the ring-shaped orifice board inside the flexible duct and the airflow adjustment apparatus. (A) Wind velocity distribution map of airflow in flexible duct, (b) Wind velocity distribution map of airflow in spiral duct Explanatory drawing of the connection structure of the conventional flexible duct and the air volume adjusting device

Explanation of symbols

1: Flexible duct 2: Air flow rate adjusting device 2a: Wind speed sensor 2b: Damper 3: Reducer 4: Short pipe 5: Short pipe provided with an orifice plate inside 5a: Orifice plate D: Inner diameter of flexible duct

Claims (2)

In a connection structure that connects a flexible duct having a bent portion upstream of an air volume adjustment device that adjusts the air supply amount in response to fluctuations in the heat load of the air conditioning target space,
A reducer and a short pipe are provided in this order between the flexible duct and the air volume adjusting device, and the airflow generated at the bent portion of the flexible duct is corrected by the reducer and the short pipe. by supplying air flow to the air velocity sensor disposed at the center of the adjusting device in a commutation state to suppress the measurement error of the air velocity sensor, Ri greens and can be supplied to the air conditioning target space air supply amount required stable,
The reducer is formed with an inner diameter difference of 40 to 60 mm between the openings at both ends and an inclination angle of 8 to 15 degrees, and the length of the short pipe connected to the reducer is equal to or less than the inner diameter D of the flexible duct. A connection structure between a flexible duct and an air flow adjusting device. In a connection structure that connects a flexible duct having a bent portion upstream of an air volume adjustment device that adjusts the air supply amount in response to fluctuations in the heat load of the air conditioning target space,
Between the flexible duct and the air volume adjusting device, a short pipe with a ring-shaped orifice plate is provided inside the vicinity of the connection end to the air volume adjusting device,
By correcting the bias of the air flow generated at the bent portion of the flexible duct with a short pipe provided with the ring-shaped orifice plate, the air flow is forcibly supplied to a wind speed sensor disposed in the center of the air volume adjusting device. suppressing the measurement error of the air velocity sensor, Ri greens and can be supplied to the air conditioning target space air supply amount required stable, short tube having a pre-Symbol annular orifice plate, equal to the inner diameter D of the flexible duct An orifice plate having an inner diameter and twice the inner diameter and having an inner diameter of 40 to 60 mm smaller than the inner diameter of the short pipe is provided in the pipe at a position of 0 to 100 mm from the connection end of the air flow adjusting device of the short pipe. A connection structure between a flexible duct and an air flow adjusting device characterized by being a thing.

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