JPH07103997A - Method and fin for measuring flow velocity of fluid, and method and device for measuring flow rate within duct - Google Patents

Abstract

PURPOSE:To provide a method for measuring a flow velocity of a fluid capable of correctly measuring the average flow velocity of the fluid flowing through a duct, and measuring the flow rate thereof, a fin for flow velocity measurement used for it, and method and device for measuring the flow rate within the duct. CONSTITUTION:In a flow rate measuring device for measuring an average velocity of a fluid within a duct 1 and for multiplying the average velocity by the cross section of the duct to compute a flow rate, one or more fins 2 are installed along the cross section within the duct 1, and also a plurality of flow velocity sensors 3 are disposed on the cross section within the duct 1 by arranging, to edges 5 of the upstream side of fins 2, sensors 3 comprising bits of single crystals of germanium mixed with impurities of proper quantities, and the average velocity of the fluid is measured in a flow velocity measuring circuit on the basis of output signals of the sensors 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a flow velocity of a fluid, a flow velocity measuring fin used therefor, a method for measuring a flow rate in a duct and an apparatus therefor, and more particularly to a velocity distribution of a fluid or a fluid flowing in a duct. As well as measuring
The present invention relates to a flow velocity measuring method and a flow velocity measuring method capable of accurately measuring an average flow velocity and measuring the flow velocity, and a flow velocity measuring fin and a flow velocity measuring device used therefor.

[0002]

2. Description of the Related Art Conventionally, when measuring the flow rate in a duct,
The difference between the total pressure and static pressure (dynamic pressure) of the fluid is detected with a Pitot tube with the tip portion inside the fluid, the square root is taken to measure the flow velocity, and the flow velocity is multiplied by the cross-sectional area of the duct to measure. The method was generally adopted.

Further, when there is a distribution of fluid velocities in the cross section of the duct, a plurality of Pitot tubes are arranged in the cross section, and a body section made of a U-shaped tube is commonly used, and the position of each Pitot tube is arranged. The average of the dynamic pressure at was detected and the square root was taken as the average flow velocity. However, since this average flow velocity is obtained by averaging the pressure proportional to the square of the velocity and then taking the square root, it is precisely the root mean square of the velocity, not the true average velocity. Therefore, the conventional flow rate measuring method has a considerable error.

Further, since normally used ducts are bent in a complicated manner and connected, the velocity vector of the fluid in the duct has an unpredictable distribution. Therefore, the velocity required to measure the flow rate is a velocity component in the direction orthogonal to the cross section of the duct, but since it actually has a velocity component parallel to the cross section of the duct, accurate flow rate measurement is not possible. could not. This problem also occurs when using a flow velocity sensor other than the Pitot tube described above.

Another problem with using the Pitot tube is that it has a large cross-sectional area at its tip, so that when a large number of Pitot tubes are arranged in the duct, the ventilation resistance increases, and the Pitot tube is used in a duct with a small diameter. In this case, the flow may be blocked, the tip may be easily clogged, and the detection sensitivity is low, so that the error is large when the wind speed is low.

As another method, there is also a method of measuring the flow velocity of a gas with a flow velocity sensor using a heat ray, but it cannot be used in the case of a flammable gas, and dust or the like ignites in a duct. There is a fear that it cannot be used.

For the measurement of the flow velocity, Japanese Patent Application Laid-Open No. 61-84563 and Japanese Patent Application Laid-Open No. 2-11032 related to the prior application of the present applicant.
There is a fluid velocity measuring method disclosed in Japanese Patent Publication No. 2 and the like.
The principle of this flow velocity measurement is that a sensor consisting of a small piece of single crystal germanium prepared by mixing an appropriate amount of impurities so that the set temperature at the time of measurement corresponds to the linear slope of the characteristic curve of resistivity vs. temperature, voltage or The current is applied to maintain the set constant temperature, and the flow velocity is measured based on the change value of the voltage or current or power accompanying the change of the sensor electrical resistance due to the temperature change of the sensor in contact with the fluid. .
Here, in order to measure the flow velocity by this flow velocity sensor, it is necessary to know the temperature of the fluid, but if the fluid has a uniform temperature, it is sufficient to measure the temperature at any one point within the flow velocity measurement range. If the fluid has a non-uniform temperature, it is necessary to measure the temperature near each flow velocity sensor.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned situation, the present invention is to solve the problem that the distribution of the flow velocity along the direction traversing the fluid and the average flow velocity can be measured, and the flow of the fluid can be measured. A method for measuring a flow velocity of a fluid which does not disturb and a fin for flow velocity measurement used for the method are provided, and an average velocity of a fluid in a duct is measured, and the average velocity is multiplied by a cross-sectional area of the duct to measure a flow rate. In addition to rectifying the fluid flowing at the position where the flow velocity is measured, a high-sensitivity flow velocity sensor other than the Pitot tube that does not change over time is used. It is another object of the present invention to provide a method and apparatus for measuring a flow rate in a duct, which can obtain a proportional output signal, measure an average velocity, and measure a true flow rate.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an upstream end edge of a fin to be placed in a fluid.
A plurality of flow velocity sensors are arranged in a row, and individual output signals of the flow velocity sensors are detected to measure the flow velocity distribution in the direction along the fins, or individual output signals of the flow velocity sensors are averaged to measure the average flow velocity. A method for measuring a fluid flow velocity is provided.

More specifically, a small piece of single crystal germanium in which the flow of the fluid is rectified by a single or a plurality of fins arranged in the fluid and an appropriate amount of impurities is mixed in the upstream end edge portion of the fin. Are arranged in a row, and the individual output signals of the flow velocity sensor are detected to measure the flow velocity distribution in the direction along the fins, or the individual output signals of the flow velocity sensor are averaged to obtain the average flow velocity. A method for measuring the flow velocity of a fluid is provided.

As a flow velocity measuring fin used in the above-described fluid flow velocity measuring method, at least the upstream end edge is streamlined, and a plurality of flow velocity sensors are arranged in line at the upstream end edge. A flow velocity measuring fin was constructed by wiring the signal line through the side surface or the inside to the end portion in the longitudinal direction or the end portion on the wake side.

Further, at least the upstream side edge is streamlined, one flow velocity sensor is arranged at the upstream side edge, and the signal line is wired to the downstream side edge through the side surface or the inside. A fin unit for flow velocity measurement, a fin unit for temperature measurement having the same cross-sectional shape as the fin unit for flow velocity measurement and a temperature sensor arranged in a proper place, and a spacer having the same cross-sectional shape as the fin unit for flow velocity measurement Fin unit and a long holding member for holding the downstream end of the fin unit, the fin units are mounted in appropriate order along the holding member, and the wiring bundle of each sensor is held. The flow velocity measuring fins are formed by leading out to the end portion in the length direction through the inside of the.

Further, the flow of the fluid is rectified by a single or a plurality of fins arranged in the duct in a direction orthogonal to the cross section of the duct, and a plurality of flow velocity sensors arranged in line at the upstream edge of the fin. Is provided to measure the average flow velocity in the duct, and the average flow velocity is multiplied by the cross-sectional area of the duct to measure the flow rate.

Then, in order to carry out the method for measuring the flow rate in the duct, the average velocity of the fluid in the duct is measured,
A flow rate measuring device in a duct, which measures the flow rate by multiplying the average velocity by a cross-sectional area of the duct, and in which a single or a plurality of fins are mounted along the cross section in the duct,
A plurality of flow velocity sensors are lined up at the upstream edge of the fin, a plurality of flow velocity sensors are lined up in the cross section inside the duct, and the average velocity of the fluid is measured by the flow velocity measurement circuit based on the output signal of the flow velocity sensor. The flow rate measuring device in the duct, which is obtained by measuring

Here, in the above-described method for measuring the velocity of the fluid, the method for measuring the flow rate in the duct and the apparatus therefor, it is preferable to use, as the flow velocity sensor, a flow velocity sensor made of a small piece of single crystal germanium mixed with an appropriate amount of impurities.
In this case, the flow velocity sensor is applied with a voltage or current to maintain a set constant temperature, and the change value of the voltage or current or power due to the change of the sensor electrical resistance due to the temperature change of the sensor in contact with the fluid. That is, the velocity of the fluid is measured by a flow velocity measuring circuit for detecting.

Further, in the flow velocity measuring fin and the flow rate measuring device in the duct, a velocity sensor is embedded in the upstream front end of the fin, and a signal line connected to the velocity sensor is provided on the surface of the fin. It is preferably formed by printed wiring.

Further, in the flow rate measuring device in the duct, the output signals of a plurality of flow velocity sensors arranged in line on one fin are collectively processed by one flow velocity measuring circuit, and the output signals of the flow velocity measuring circuits are processed by the flow velocity sensor. It is more preferable to set the flow velocity measurement signal per one.

[0018]

The method of measuring the flow velocity of a fluid and the fin for measuring the flow velocity and the method of measuring the flow rate in the duct of the present invention, which have the above-mentioned contents, and the apparatus therefor are arranged in the fluid or attached in the duct. A plurality of fins arranged in a row at the upstream end edge of the fins are arranged to rectify the fluid flowing through the fins, or to orient the velocity velocity of the fluid in the direction perpendicular to the cross section of the duct at the flow velocity measurement position. The flow velocity is measured at the position of the flow velocity sensor. Also, by arranging fins in which a plurality of flow velocity sensors are arranged in line in the fluid or in the duct, the position of the flow velocity sensor in the cross section of the fluid or the duct, that is, the sampling position of the flow velocity, should be set so as not to be substantially biased. Is possible. Furthermore,
By averaging the flow velocities at each position measured at the multiple positions, it is possible to measure the average velocity in the direction orthogonal to the cross section of the duct, and the flow rate can be calculated by multiplying the average velocity by the cross sectional area of the duct. It can be easily measured.
The arithmetic processing for multiplying the average flow velocity by the cross-sectional area may be performed using a multiplier or may be performed using a microcomputer.

As described above, the fins direct the flow of the fluid in the direction orthogonal to the cross section of the duct, thereby eliminating the velocity component parallel to the cross section of the duct that does not contribute to the flow rate.
Alternatively, it is made negligibly small to improve the flow rate measurement accuracy. Also, as the flow velocity sensor, by using a flow velocity sensor consisting of a small piece of single crystal germanium mixed with an appropriate amount of impurities, it is possible to measure the flow velocity accurately over a long period without change over time, and with high sensitivity even to a slight wind. Yes It is possible to accurately measure a minute flow rate.

Further, the flow velocity sensor is embedded in the upstream front end portion of the fin, and the signal line connected to the flow velocity sensor is formed by printed wiring on the surface of the fin. It is possible to arrange a plurality of flow velocity sensors in a line in the duct by attaching the fins to the duct while not disturbing the flow of the fluid with the signal line.

Further, output signals of a plurality of flow velocity sensors arranged in a row on one fin are collectively processed by one flow velocity measuring circuit,
By setting the output signal of the flow velocity measurement circuit to be the flow velocity measurement signal for each flow velocity sensor, compared to the conventional flow velocity measurement method in which one flow velocity measurement circuit is used for each flow velocity sensor. The number of measurement circuits can be 1 / n (n is the number of flow velocity sensors attached to one fin). This is because what is needed to measure the flow rate is the average flow velocity, and it is not necessary to separately process the output signals of the individual flow velocity sensors and measure the flow velocity at that position. Further, by using one fin having a flow velocity sensor and one flow velocity measuring circuit as one unit, the number of units is increased when it is necessary to measure the flow rate with high accuracy,
If the accuracy may be relatively low, the number of units may be reduced.

Further, as a flow velocity measuring fin, a flow velocity measuring fin unit is provided in which one flow velocity sensor is arranged at the upstream side edge portion and the signal line thereof is wired to the wake side end portion through the side surface or inside. A temperature-measuring fin unit having the same cross-sectional shape as the flow velocity measuring fin unit and a temperature sensor arranged in a proper place; a spacer fin unit having the same cross-sectional shape as the flow velocity measuring fin unit; It is composed of a long holding member that holds the wake side end portion, and the fin unit is attached along the holding member in an appropriate order to attach a desired number of fin units, so that the fin unit It is possible to set the length. Further, the sampling intervals can be adjusted by arranging the flow velocity measurement fin units in a row with one or more spacer fin units interposed. Furthermore, by simultaneously measuring the temperature of the fluid in combination with an appropriate number of temperature measurement fin units, even if the fluid has a uniform temperature distribution,
It is possible to improve the accuracy of flow velocity measurement performed using the flow velocity sensor that is affected by the temperature of the fluid, even if the temperature of the fluid changes over time, even if the temperature distribution of the fluid is non-uniform. The wiring bundle of each sensor is led out to the end in the length direction through the inside of the holding member, so that the wiring bundle does not disturb the flow of fluid.

[0023]

The present invention will be described in more detail with reference to the embodiments shown in the accompanying drawings. 1 and 2 show a typical embodiment of the present invention, in which a flow velocity measuring circuit and a cord connected thereto are omitted, wherein 1 is a duct, 2 is a fin,
3 has shown the flow velocity sensor, respectively. In this embodiment,
The description will be given based on an example of measuring the flow velocity and flow rate in the duct 1, but the same can be applied to the case of measuring the flow velocity in a general fluid, but in this case, the space is not limited, and thus in a strict sense. However, the flow rate per unit area can be measured.

According to the present invention, the flow of the fluid is rectified in the direction orthogonal to the cross section of the duct 1 by the single or plural fins 2, ... Arranged in the duct 1, and the upstream edge of the fins 2 ,. The flow rate in the duct is measured by averaging the output signals of a plurality of flow rate sensors 3 arranged in a line to measure the average flow rate in the duct and multiplying the average flow rate by the cross-sectional area of the duct to measure the flow rate. The method is the gist. Here, the flow velocity sensor 3 is preferably made of a small piece of single crystal germanium mixed with an appropriate amount of impurities, which has already been provided by the present applicant. Further, in order to measure the average velocity along the length direction of the fin 2, even if the flow velocity at each position is measured from the output signal of each flow velocity sensor 3, ... And it is deductively averaged, The output signals of the flow velocity sensors 3, ... May be averaged for all or for each group, and the velocity (average velocity) may be measured from the averaged output signal.

Further, the present invention is a flow rate measuring device in a duct, wherein an average velocity of a fluid in the duct 1 is measured, and the average velocity is multiplied by a cross-sectional area of the duct 1 to measure a flow rate.
A single or a plurality of fins 2, ... Is mounted along the cross section in the duct 1, and a plurality of flow velocity sensors 3 ,. In the above, the gist is a flow rate measuring device in a duct in which a plurality of flow velocity sensors 3, ... Are arranged in a line and an average velocity of a fluid is measured by a flow velocity measuring circuit based on an output signal of the flow velocity sensor 3.

The cross-sectional shape of the duct 1 may be rectangular as shown in FIG. 1 or circular as shown in FIG. 2, and both sides thereof may be connected to another blower duct (not shown). Flanges 4 and 4 are formed around the edges. Then, a plurality of, in this embodiment, four fins 2, ... Are mounted in parallel in the rectangular duct 1 of FIG. 1 at equal intervals, and two fins 2, 2 are provided in the circular duct 1 of FIG. 2 is installed in a cross shape.

As shown in FIG. 3, the fin 2 is formed by using a double-sided printed circuit board made of epoxy resin in which at least the upstream side edge 5 is router-processed in a streamlined manner.
If the inner diameter of the duct 1 is large and the fins 2 need to be long, and the bending strength is insufficient, the same printed circuit board as above is laminated and fixed on both sides of a core material made of metal or the like. To do.

The flow velocity sensor 3 uses a sensor chip 6 made of a small piece of single crystal germanium mixed with an appropriate amount of impurities, and a conductive metal such as gold, silver or platinum is deposited on both end faces of the sensor chip 6. To form the electrodes 7 and 7, and lead wires 8 and 8 such as gold wires to the electrodes 7, respectively.
Is bonded to the inside of the concave portion 9 formed by cutting out a part of the edge portion 5 of the fin 2, and the covering material 10 such as epoxy resin having high thermal conductivity is filled in the concave portion 9 and fixed. is doing. Here, the coating material 10 is formed such that the surface thereof is flush with the outer shape of the end edge portion 5 of the fin 2, and the flow velocity sensor 3 is substantially embedded in the upstream end edge portion 5 of the fin 2. In the example, four flow velocity sensors 3, ... Are integrally attached to one fin 2 at equal intervals. Further, the sensor chip 6 can utilize its characteristics up to a temperature of about 145 ° C., and the covering material 10 can withstand about 140 ° C.,
The temperature of the fluid that can be practically used is in the range of 0 to 50 ° C., and favorable results are obtained within that temperature range. This temperature range is sufficient to measure the flow rate in air conditioning ducts for heating and cooling.

Signal wires 11, 11 connected to the lead wires 8, 8 of each flow velocity sensor 3 are provided on both side surfaces of the fin 2.
Is formed into a desired pattern by printed wiring and is guided to the end portion in the length direction of the fin 2 or the end edge portion on the wake side.
The signal line 11 may be guided through the inside of the fin 2 to the longitudinal end portion or the wake side edge portion. In this embodiment, the signal line 11 extends from the mounting position of the flow velocity sensor 3 to the wake side, further extends to one end in the length direction of the fin 2, and has a wide connection portion 12 formed at the end thereof. It is a thing. It should be noted that the flow velocity sensor 3 includes the signal lines 11 and 11
After the lead wires 8 and 8 are connected to each other, they are fixed with the covering material 10 to make them non-directional with respect to the fluid flow direction.
The surface of the fin 2 is resin-coated except for the connection portion 12 to be dust-proofed and moisture-proofed.
The flow velocity sensor 3 can be embedded in the upstream edge of the fin 2 by exposing a part of the sensor chip 6 so as to have directivity.

One end of the fin 2 in the lengthwise direction is fitted to a board socket such as an edge card or a multipolar connector 13,
It can be fixed to the wall surface of the duct 1 through the multipolar connector 13, and the other end can also be fixed to the wall surface of the duct 1 through a fixing tool (not shown). The multi-pole connector 13 includes the connecting portions 12, ...
Are provided on the inner surface of the fitting portion, and the wiring (not shown) connected to each electrode piece 14, ... Is drawn out of the duct 1 and connected to the flow velocity measuring circuit.

The principle of measuring the flow velocity by the flow velocity sensor 3 is that the flow velocity sensor 3 operates from the constant current source of the flow velocity measuring circuit.
In addition, a voltage is applied to maintain a set constant temperature, and a change value of voltage or current or power due to a change in sensor electrical resistance due to a change in sensor temperature due to contact with a fluid is detected.

The shape of the sensor chip 6 is arbitrary, but in order to simplify the manufacturing process of the sensor chip 6 itself and the vapor deposition process of the electrodes 7, it is preferable that the sensor chip 6 is a rectangular parallelepiped or a cube. The length is 1 mm, one side of the short side is 0.3 mm, and in the case of a cube, one side is about 0.5 mm. The characteristic curve of the specific resistance of germanium vs. temperature has a tendency that the resistance increases linearly from about 400 ° C. to a certain temperature as the temperature decreases on a logarithmic scale, and conversely decreases at lower temperatures. The temperature at which the above-mentioned characteristic curve deviates from the straight line becomes higher and the specific resistance decreases as the amount of impurities mixed in increases. Therefore, as the amount of impurities mixed in is smaller, the linearity on the logarithmic scale is better up to low temperature, but the resistance at low temperature increases. For example, when impurities of about 10 ¹² atoms / cm ³ are mixed, the specific resistance at 0 ° C. is several hundred Ω · cm, and the specific resistance at 100 ° C. is 5 to 6 Ω · cm. Although the set temperature of the sensor chip 6 is set higher than the temperature range of the fluid, when the specific resistance is large, a small current is sufficient to maintain the sensor chip 6 at a high temperature, but the power consumption is large and the specific resistance is small. In this case, a large current is required to maintain the sensor chip 6 at a high temperature, but the power consumption is small. Therefore, it is necessary to set the amount of impurities in the sensor chip 6 to be optimum from the relationship between the set temperature of the sensor chip 6 according to the temperature of the fluid and the power consumption.

Further, another embodiment of the present invention shown in FIGS. 6 and 7 is disclosed in Japanese Patent Application Laid-Open No.
An off-the-shelf velocity sensor 3a provided in Japanese Patent No. 110322 and Japanese Utility Model Laid-Open No. 4-138274 is used, and the velocity sensor 3a is fixed to the upstream edge 5 of the fin 2. That is, the flow velocity sensor 3a includes two conductive wires 1
A spherical covering member 17 in which the sensor chip 6 in which the lead wires 8 and 8 are connected to the conductive wires 15 and 15 are embedded at the tips of the support rods 16 which are separated from each other and covered with synthetic resin.
Is fixed. Then, with the covering member 17 having the sensor chip 6 attached thereto facing the upstream side, the base end of the support rod 16 is positioned in the recess 9 formed by cutting out a part of the fin 2, The conductive wires 15 and 15 and the signal wires 11 and 11 printed on both sides of the fin 2 are connected by connecting wires 18 and 18, and the covering material 10 is filled and fixed in the same manner as described above.

The fin 2 may be of a split type in which each function is unitized, in addition to the above-described long integral body. That is, the flow velocity measuring fin 2 is
As shown in FIGS. 8 to 10, at least the upstream end edge portion 5
Is a streamlined structure, one flow velocity sensor 3 is arranged at the upstream edge 5, and the signal lines 11 and 11 are wired to the downstream side end through the side surface or the inside. 19 and the fin unit 1 for measuring the flow velocity
9, a temperature measuring fin unit 21 having the same cross sectional shape as that of the temperature sensor 20 in place, a spacer fin unit 22 having the same cross sectional shape as the flow velocity measuring fin unit 19, and their wakes. The holding member 24 includes a long holding member 24 that holds the side end portion 23.
The fin units 19, 21, 22, ... Are mounted in an appropriate order along with, and the wire bundle 25 of each sensor 3, 20, ... Is led out to the end in the length direction through the inside of the holding member 24. It is a thing.

Here, the holding member 24 is a long extruded product having a substantially U-shaped cross section and made of an insulating material made of synthetic resin, and a pair of holding pieces 26, 26 and wiring at the inner rear end thereof. The space 27 is formed. Here, the outer shape of the holding member 24 needs to be streamlined so as not to disturb the flow of fluid. Then, both holding pieces 26, 26
The fin units 19, 21, 22, ... Are fitted together in an appropriate order and fixed by an adhesive to form an integral fin 2. In this case, the fin units 19, 21, 22 have the same outer shape, and the surfaces of the fin units 19, 21, 22 are continuous when they are mounted on the holding member 24.

FIG. 9 shows the fin unit 1 for measuring the flow velocity.
9 and the temperature measurement fin unit 21 are alternately arranged, and FIG. 10 shows an example in which the flow velocity measurement fin unit 19 and the spacer fin unit 22 are alternately arranged. 19,21,22
Other combinations and arrangements of can be freely performed. For example, in FIG. 10, the arrangement in which one spacer fin unit 22 is replaced with the temperature measurement fin unit 21 is effective when the fluid has a uniform temperature distribution. The above-described arrangement of FIG. 9 is effective when the fluid has a non-uniform temperature distribution, and the flow velocity measurement data by a certain flow velocity sensor 3 is corrected by the temperature of the temperature sensor 20 adjacent thereto to obtain an accurate flow velocity. It can be measured.

The above-mentioned integral fin 2 or each fin unit 19, 21, 22 is formed of a plating-compatible synthetic resin, and the signal line 11 is formed on the side surface by partial plating of a conductive metal. Is also possible.

Further, in the present invention, in the flow velocity sensor 3, the sensor chip 6 is arranged in the recess 9 formed in the upstream end edge portion 5 of the fin 2, and the coating material 10 made of synthetic resin having high thermal conductivity is used. By covering and embedding the structure and making the outer shape streamlined, it is possible to obtain a directivity with a far wider angle than that of the Pitot tube. For example, the angle at which the flow velocity can be measured within an error range of about 3% is ± 15 ° for the Pitot tube and ± 45 ° for the elevation angle of the fin 2 in the flow velocity sensor 3 of the present invention. As a result, a flow having an angle on the main axis can be accurately measured, and a flow whose direction changes can be accurately measured.

When the flow velocity sensor 3 of the present invention is embedded in the fin 2 having a large heat capacity, it does not respond to a slight change in flow velocity and is placed in a turbulent flow such as a fluid flowing in the duct 1. Even so, since the output signal is a steady signal with little temporal fluctuation, like the signal processing in the flow velocity sensor disclosed in Japanese Patent Laid-Open No. 2-110322 or the like,
Since the averaging processing in time is not required in the electric circuit or the arithmetic processing, the measuring circuit becomes simple.

FIG. 11 shows a simplified flow velocity measuring circuit. In this embodiment, two sensor chips 6 and 6 are used.
Connected in series are further connected in parallel, one end of which is connected to the constant current power supply 28, and the other end is connected to the potentiometer 29.
Is connected to the constant current power source 28 via the so as to supply a current so that the sensor chip 6 reaches a set temperature. The potentiometer 29 is for balancing the currents flowing through the sensor chips 6 connected in parallel, and may be omitted. When a fluid, for example, conditioned air, flows into the duct 1, the flow velocity sensor 3 attached to the upstream edge 5 of the fin 2
The heat of the sensor chip 6 is removed through the coating material 10 and the temperature of the sensor chip 6 is lowered. As a result, the voltage across the sensor chip 6 having a higher specific resistance is increased. This voltage is converted into a voltage proportional to the output voltage of one sensor chip 6, and is detected by the voltage detection circuit 30 having a low-pass filter function, and the detected voltage is compared with the state in which the fluid is stationary. After the difference with the voltage is detected by the differential amplifier 31, it is amplified by the amplifier 32 having a variable amplification degree to obtain a desired output voltage signal. The output voltage signal of this flow velocity measuring circuit is
.. are binarized by the A / D converter and processed by a microcomputer to calculate the average flow velocity at the positions of the flow velocity sensors 3, ... The average flow velocity in the cross section of the duct 1 is calculated from the average flow velocity, and then the flow velocity is calculated by multiplying this average flow velocity by the data of the cross-sectional area of the duct 1 which is input in advance. In addition to the above-described method, the sensor chips 6, ... Provided on one fin 2 may be connected in series, or may be connected in parallel. It is possible.

As described above, by mounting the plurality of fins 2, ... Having the plurality of flow velocity sensors 3, ... arranged in the upstream end edge portion 5 in the duct 1 at equal intervals, as shown in FIG.
It is possible to disperse and arrange a plurality of flow velocity sensors 3 in the cross section of the duct 1 substantially evenly, and average the output signals based on the flow velocity detected by the flow velocity sensor 3 at each position in the cross section of the duct 1. The average speed is then measured.

Further, as shown in FIGS. 12 and 13, the fins 2, ... Are axially mounted in the duct 1 so as to be movable, and the angle thereof can be changed by interlocking with a servo motor or the like not shown. By doing so, the flow rate can be adjusted by continuously changing the fully open state of FIG. 12 to the reduced flow rate of FIG. However, it is necessary to change the pair of adjacent fins 2 and 2 into a V shape so as not to impair the original rectifying function of the fin 2.

The present invention is an apparatus capable of accurately measuring the flow velocity and flow rate in the duct 1. However, the flow rate in a plurality of ducts 1, ...・ Area network (LA
It is also possible to construct N) and control the amount of air supplied to each room. That is, as shown in FIG. 14, the main building management mainframe 33 and the floor controller 34 installed on each floor are connected by a communication trunk line (internet), and each floor controller 34 and each room on that floor are connected. , And the room controllers 35, ... The room controller 35 has the flow velocity measuring circuit and a microcomputer built therein, and monitors the flow rate of the duct 1 for supplying conditioned air to each room, the temperature and humidity of each room, and concentrates on the duct 1. The flow rate of the conditioned air supplied from the cooling and heating equipment to the duct 1 is controlled. For example, in a conference room where a large number of conferences are held, a room in which a large number of heat-generating devices such as OA devices are installed, and a room in which a large number of devices are not installed, even if the same amount of air is blown, there is a large difference in cooling and heating effects. In this way, by controlling the flow rate of conditioned air supplied to each room,
It is possible to create a comfortable environment by adjusting the air flow rate suitable for the room, and avoid overcooling or overheating, thus improving the energy consumption efficiency of the entire building.

[0044]

According to the fluid velocity measuring method of the present invention as described above, the velocity distribution along the length direction of the fins arranged in the fluid can be measured without disturbing the fluid flow. At the same time, the average flow velocity within the measurement range can be measured.

Further, in the flow velocity measuring fin of the present invention, since a plurality of flow velocity sensors are arranged in line at the upstream end edge, the fluid can be measured by simply disposing the fins in the fluid or in the duct. A plurality of flow velocity sensors can be arranged across the flow of the fluid without any other holding means being used in the area.

Further, the fins are composed of a fin unit for flow velocity measurement, a fin unit for temperature measurement, a fin unit for spacers and a holding member for holding the wake side end portions thereof, and each fin unit is appropriately ranked as a holding member. By installing them in combination, the length can be adjusted and set according to the width of the flow velocity measurement range, and even if the temperature of the fluid changes, the flow velocity and flow rate can be accurately measured even if there is a spatial distribution. It can be measured.

According to the method for measuring the flow rate in the duct and the apparatus therefor according to the present invention, the fluid flowing in the duct is rectified by the fin or fins mounted in the duct, and the flow of the fluid is cross-sectioned in the duct. By orienting in the direction orthogonal to
The velocity components parallel to the cross section of the duct that do not contribute to the flow rate are eliminated or reduced to a negligible level. Is measured and the flow velocity at each position is averaged, the average velocity in the direction orthogonal to the cross section of the duct can be accurately measured, and by multiplying this average flow velocity by the cross sectional area of the duct, The flow rate can be measured accurately.
Further, since each flow velocity sensor is integrated with the fin, by mounting the fin at a predetermined position in the duct, the position of the flow velocity sensor in the cross section of the duct, that is, the sampling position of the flow velocity is not substantially biased. Can be set. In addition, by using a flow velocity sensor consisting of a small piece of single crystal germanium mixed with an appropriate amount of impurities as the flow velocity sensor, it is possible to measure the flow velocity accurately for a long time without change over time, and it is also highly sensitive to breeze. A minute flow rate can also be measured accurately.

Further, the flow velocity sensor is embedded in the upstream front end of the fin, and the signal line connected to the flow velocity sensor is formed by printed wiring on the surface of the fin. It is possible to arrange a plurality of flow velocity sensors in a line in the duct by attaching the fins to the duct while not disturbing the flow of the fluid with the signal line. Furthermore, when the flow velocity sensor is embedded in a fin with a large heat capacity, a wider angle of directivity can be obtained compared to a Pitot tube, and even if it is placed in a turbulent flow such as a fluid flowing in a duct, Since it has little effect on the fluctuation of the flow rate and does not respond instantly to the temporal fluctuation of the flow velocity, the flow velocity can be measured accurately, and the process of averaging the output signal over time is not required. The circuit becomes simple.

Furthermore, the output signals of a plurality of flow velocity sensors arranged in a row on one fin are collectively processed by one flow velocity measuring circuit,
By setting the output signal of the flow velocity measurement circuit to be the flow velocity measurement signal for each flow velocity sensor, compared to the conventional flow velocity measurement method in which one flow velocity measurement circuit is used for each flow velocity sensor. The number of measurement circuits can be 1 / n (n is the number of flow velocity sensors attached to one fin),
The cost increase can be suppressed to a minimum. Also, by using one fin with a flow velocity sensor and one flow velocity measuring circuit as one unit, if the flow rate needs to be measured with high accuracy, the number of units is increased and the accuracy is relatively low. If it's okay, reduce the number of units
It is highly versatile.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a rectangular duct with fins integrated with a flow velocity sensor according to a representative embodiment of the present invention.

FIG. 2 is a schematic perspective view of a circular duct of the same.

FIG. 3 is an enlarged perspective view of a main part of the present invention.

FIG. 4 is a partial front view of the fin seen from the upstream side.

FIG. 5 is a sectional view of the main part of the fin.

FIG. 6 is a cross-sectional view of an essential part showing another attachment structure of the flow velocity sensor.

FIG. 7 is a side view of the main part of the same.

FIG. 8 is an abbreviated perspective view of an essential part showing a state in which a plurality of types of split fin units having various functions are mounted on a holding member.

FIG. 9 is a side view with the flow velocity measuring fin unit and the temperature measuring fin unit alternately mounted in an alternating manner.

FIG. 10 is a side view with the flow velocity measuring fin unit and the spacer fin unit alternately mounted in an abbreviated manner.

FIG. 11 is a simplified circuit diagram of a flow velocity measuring circuit used in the present invention.

FIG. 12 is a simplified cross-sectional view of a duct in a fully opened state when the flow rate is adjusted using movable fins.

FIG. 13 is a schematic cross-sectional view of the duct in the same state where the flow rate is reduced.

FIG. 14 is a simplified explanatory view showing a centralized heating and cooling system for a building using the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 duct 2 fins 3,3a flow velocity sensor 4 flange 5 edge part 6 sensor chip 7 electrode 8 lead wire 9 recess 10 coating material 11 signal line 12 connection portion 13 multipolar connector 14 electrode piece 15 conductive wire 16 support rod 17 coating member 18 Connection Line 19 Flow Rate Measurement Fin Unit 20 Temperature Sensor 21 Temperature Measurement Fin Unit 22 Spacer Fin Unit 23 Backflow Side End 24 Holding Member 25 Wiring Bundle 26 Clamping Piece 27 Wiring Space 28 Constant Current Power Supply 29 Potentiometer 30 Voltage Detection circuit 31 Differential amplifier 32 Amplifier 33 Building management mainframe 34 Floor controller 35 Room controller

Claims (17)

[Claims] 1. A plurality of flow velocity sensors are arranged in a row at an upstream edge of a fin arranged in a fluid, and an individual output signal of the flow velocity sensor is detected to obtain a flow velocity distribution in a direction along the fin. A method for measuring the flow velocity of a fluid, which comprises measuring or averaging individual output signals of the flow velocity sensor to measure the average flow velocity. 2. A plurality of fins arranged in the fluid for rectifying the flow of the fluid, and a plurality of small pieces of single crystal germanium mixed with an appropriate amount of impurities at the upstream edge of the fin. Flow velocity sensors are arranged in a row, and individual output signals of the flow velocity sensors are detected to measure the flow velocity distribution in the direction along the fins, or individual output signals of the flow velocity sensors are averaged to measure the average flow velocity. A method for measuring the flow velocity of a fluid. 3. A voltage or current is applied to the flow velocity sensor to maintain a set constant temperature, and the voltage or current or power is changed in accordance with a change in sensor electrical resistance due to a temperature change of the sensor in contact with a fluid. The fluid flow velocity measuring method according to claim 2, wherein the fluid velocity is measured by a flow velocity measuring circuit for detecting a change value. 4. At least the upstream end edge portion is streamlined, a plurality of flow velocity sensors are provided in a row at the upstream end edge portion, and the signal line thereof is passed through the side surface or inside to the longitudinal direction end portion or wake. A fin for flow velocity measurement, characterized in that wiring is provided at a side edge portion. 5. At least the upstream side edge portion is streamlined, one flow velocity sensor is arranged at the upstream side edge portion, and the signal line thereof is wired to the downstream side edge portion through a side surface or inside. A fin unit for flow velocity measurement, a fin unit for temperature measurement having the same cross-sectional shape as the fin unit for flow velocity measurement and a temperature sensor arranged in a proper place, and a spacer having the same cross-sectional shape as the fin unit for flow velocity measurement Fin unit and a long holding member for holding the downstream end of the fin unit, the fin units are mounted in appropriate order along the holding member, and the wiring bundle of each sensor is held. A fin for flow velocity measurement, characterized by being led out to the end in the length direction through the inside of the. 6. The flow velocity measuring fin according to claim 4, wherein the flow velocity sensor is a flow velocity sensor formed of a small piece of single crystal germanium mixed with an appropriate amount of impurities. 7. The flow velocity measuring fin according to claim 4, 5 or 6, wherein a flow velocity sensor is embedded in the upstream front end portion. 8. The signal line connected to the flow velocity sensor is formed by printed wiring on the surface.
Alternatively, the flow velocity measurement fin according to item 7. 9. A plurality of flow velocity sensors arranged in an upstream end edge portion of the fin while rectifying a flow of fluid in a direction orthogonal to a cross section of the duct by one or a plurality of fins arranged in the duct. Is averaged to measure the average flow velocity in the duct, and the average flow velocity is multiplied by the cross-sectional area of the duct to measure the flow rate. 10. The method for measuring a flow rate in a duct according to claim 9, wherein the flow velocity sensor is a flow velocity sensor made of a small piece of single crystal germanium mixed with an appropriate amount of impurities. 11. A voltage or current is applied to the flow velocity sensor to maintain a set constant temperature, and the voltage or current or power of the sensor is changed due to a change in the sensor electrical resistance due to a temperature change of the sensor in contact with a fluid. The flow rate measuring method in a duct according to claim 10, wherein the velocity of the fluid is measured by a flow velocity measuring circuit that detects a change value. 12. A flow rate measuring device in a duct, comprising: measuring an average velocity of a fluid in a duct; multiplying the average velocity by a sectional area of the duct to measure a flow rate; And installing a single or multiple fins, and arranging a plurality of flow velocity sensors in line at the upstream edge of the fins,
A flow rate measuring device in a duct, wherein a plurality of flow velocity sensors are arranged in a line in a cross section in the duct, and an average velocity of the fluid is measured by a flow velocity measuring circuit based on an output signal of the flow velocity sensor. 13. The flow rate measuring device in a duct according to claim 12, wherein the flow velocity sensor is a flow velocity sensor made of a small piece of single crystal germanium mixed with an appropriate amount of impurities. 14. A voltage or current is applied to the flow velocity sensor to maintain a set constant temperature, and the voltage or current or power of the sensor changes due to a change in the sensor electrical resistance due to a temperature change of the sensor in contact with a fluid. 14. The flow rate measuring device in the duct according to claim 13, wherein the velocity of the fluid is measured by a flow velocity measuring circuit that detects a change value. 15. The flow rate measuring device in a duct according to claim 12, wherein a flow velocity sensor is embedded in a front end portion of the fin on the upstream side. 16. The signal line connected to the flow velocity sensor is formed by printed wiring on the surface of the fin.
The flow rate measuring device in the duct according to 2 or 13 or 14. 17. A single flow velocity measuring circuit collectively processes the output signals of a plurality of flow velocity sensors arranged in a row on one fin, and the output signals of the flow velocity measuring circuits are used as flow velocity measuring signals for each flow velocity sensor. The method according to claim 12 or 13, wherein
Or the flow rate measuring device in the duct according to 14.