JPH027431B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a detection body for a thermoelectric wind direction, anemometer, and temperature meter that can simultaneously measure wind direction, wind speed, and wind temperature at the same locality in a two-dimensional flow.

Conventionally, this type of detecting body for a thermoelectric type wind direction anemometer anemometer seems not to be known.

As disclosed in Japanese Patent Publication No. 46-18793 as a third embodiment, a conventional wind vane has a handle tube rotatably attached to a dial on the base, and a single main tubular tube at the tip of the handle tube. In addition to protruding columns, two tubular sub-pillars are protruded from diagonally rearward positions of the tubular main column, and a semiconductor whose resistance changes depending on temperature is placed between the tubular main column and the tip of each tubular sub-pillar. A bridge circuit is constructed by arranging both semiconductors in a V-shape, two variable resistors, a power supply, and a measuring device.

When using this anemometer, first place both semiconductors, which generate heat when energized, in still air. Adjust the resistance value of the resistor.

Next, place both semiconductors, which generate heat when energized, at the measuring point in the airflow, and if the pointer of the measuring device does not point to zero, rotate the handle tube so that the pointer of the measuring device points to zero. The direction of the airflow is determined by changing the direction of the stem tube in this way, that is, making the angle of the airflow hitting both semiconductors equal, and reading the direction of the stem tube at that time from the dial.

However, this wind vane uses the so-called zero position method to measure by rotating the handle tube and detecting the direction of the handle tube in which the pointer of the measuring instrument points to zero. It cannot be used in the case of steady airflow or when the airflow flows over the surface of a rotating or moving object, and the wind direction cannot be measured.

In addition, this wind vane has a handle tube on the scale plate of the base,
The main tubular pillar and the secondary tubular pillar are attached to the tip of the stem tube, and the semiconductors are attached to the tips of the main tubular pillar and the secondary tubular pillar, making it large-sized. Therefore, the wind vane itself greatly disturbs the airflow at the measurement point, and cannot be used when the airflow flows through a narrow space.

In addition, this wind vane uses a bridge circuit to detect the resistance value of a heating semiconductor that is cooled by the collision of airflow, but the resistance value of the semiconductor also changes depending on the temperature of the airflow. Moreover, since the temperature characteristics of both semiconductors are not exactly the same, measurement accuracy deteriorates when the temperature of the airflow changes.

Furthermore, this wind vane cannot measure wind direction and wind speed at the same time, nor can it measure wind direction, wind speed, and wind temperature at the same time.

An object of the present invention is to solve the conventional problems as described above.

First, a detecting body for a thermoelectric anemometer related to the detecting body for a thermoelectric anemometer of the present invention will be explained.

As shown in FIG. 1, the detecting body 1 for the thermoelectric anemometer consists of a central part on the windward side and a left part on the leeward side of the upper surface 3 of a disc-shaped base 2 made of an electric insulator such as ceramic or synthetic resin. and on the right side, the tips of phosphor bronze supports 4, 5, and 6 for heating wires are protruded to equal lengths,
Nichrome heating wires 7 and 8 are connected between the ends of the pillar 4 on the windward side central part and the pillar 5 on the left side on the leeward side, and between the ends of the pillar 4 on the windward side central part and the pillar 6 on the right side on the leeward side, respectively. , electrically heated heating wires 7, 8
are stretched on the left and right sides of the base body 2, respectively, and the left and right heating wires 7 and 8 are arranged at the same height and perpendicular to each other. In addition, the tips of first struts 9, 10 and second struts 11, 12 made of alumel for thermocouples are protruded from the leeward side of the left heating wire 7 and the leeward side of the right heating wire 8 of the upper surface 3 of the base body, respectively. , between the center of the left heating wire 7 and the tip of the first left support 9, and the right heating wire 8
The first thermocouple wires 13 and 14 made of alumel wire are connected between the center and the tip of the first right support 10, respectively, and the first thermocouple wires 13 and 14 are connected between the center and the tip of the first right support 10, and the position close to the heating wire connection end 15 of the first left thermocouple wire 13 and the second left support support are connected. Between the tips of 11 and the first on the right
Second thermocouple wires 17 and 18 made of chromel wire are connected between a position close to the heating wire connection end 16 of the thermocouple wire 14 and the tip of the right second support 12, respectively, and a first thermocouple wire made of alumel wire on the left Those on the right 1
4, 10, 12, and 18 respectively constitute a thermocouple, and both the first and second thermocouples on the left side have the same temperature as the center of the left heating wire 7, which is cooled according to the direction and speed of the airflow F. The connection point 19 of the pair wires 13, 17 and the connection point 20 of the first and second thermocouple wires 14, 18 on the right side are connected to the left thermocouples 13, 9, 11, respectively.
17. Connection point 2 between the second thermocouple wire 17 on the left side and the second support column 11, which serves as a high temperature contact point for measuring wind direction and speed of the right thermocouples 14, 10, 12, and 18, and has the same temperature as the air flow F.
1 and a similar connection point 22 between the right second thermocouple wire 18 and the second support 12 are connected to the left thermocouple 13,
9, 11, 17, right thermocouple 14, 10, 12,
18 low-temperature contacts for wind temperature correction.

The dimensions of each part of the detection object 1 are that the diameter and thickness of the base 2 are 8 mm and 3 mm, and the heating wires 7 on the left and right,
8 length, thickness and height are 5mm, 0.05mm and 5mm
The length and thickness of the protruding tips of each of the left and right first columns 9, 10 and each second column 11, 12 are 2 mm.
0.3 mm, and the first thermocouple wires 13 and 14 on the left and right
The thickness of each second thermocouple wire 17, 18 is 0.025 mm.

When using the detection body 1, as shown in FIG. A power supply 25 that heats them by passing a constant current through the hot wires 7 and 8 is connected, and a wire is connected between the ends of both the first and second columns 9 and 11 on the left side for the thermocouple protruding from the bottom surface of the base 2, and the like. Left thermocouples 13, 9, 11, 17, right thermocouples 14, 10,
Voltmeters 26, 2 for measuring thermoelectromotive voltages 12, 18
Connect 7. On the other hand, left and right heating wires 7 and 8 provided on the base 2 and left and right first and second thermocouple wires 1
3, 14, 17, 18 and the first and second pillars 9, 1
Insert the protruding tips of 0, 11, and 12 into the airflow F, align the plane containing both the left and right heating wires 7 and 8 with the plane in which the direction of the airflow F swings, and connect the orthogonal ends of the heating wires 7 and 8. The base body 2 is fixed by placing the other ends of the heating wires 7 and 8 on the windward side and on the leeward side. Note that when measuring the flow on the surface of a rotating body, the detection object 1 of this example is attached to the rotating body, for example, the blade of a propeller fan.
is installed as described above, and a slip ring is installed on the rotating shaft of the propeller fan, and the detection object 1, power supply 25, and voltmeters 26, 27 are connected through this slip ring.
Connect as above.

For the detection object 1, the direction θ and speed U of the airflow F can be determined from the voltage E ₁ measured by the voltmeter 36 for the left thermocouple and the voltage E ₂ measured by the voltmeter 27 for the right thermocouple. It is necessary to obtain the characteristic expression between them in advance as explained below. Airflow F
The state shown in Fig. 3 in which θ hits the left heating wire 7 and the right heating wire 8 of the orthogonal arrangement at an angle of 45 degrees is θ=0.
Taking the reference state of , in this reference state,
The characteristic equation is from the forced convection heat transfer equation for a cylindrical heating wire: E ₁ = A ₁・U ^-n E ₂ = A ₂・U ^-m (1) That is, lnE ₁ = −n ・ lnU + lnA ₁ lnE ₂ =-m・lnU+lnA ₂ . However, A ₁ , A ₂ , n, and m are constants.

This first characteristic equation is calculated by measuring the voltages E ₁ and E ₂ while changing the speed U to various values in the standard state, and
and the natural logarithms of the voltages E ₁ and E ₂ are calculated and obtained as a diagram of lnE ₁ vs. lnU and lnE ₂ vs. lnU, as shown in FIG.

On the other hand, the direction of the airflow F is at a certain angle from the reference state -
In the state shown in Fig. 5 where the angle is tilted at θ,
The characteristic formula is E ₁ = f ₁ (θ)・A ₁・U ^-n E ₂ = f ₂ (θ)・
A ₂ ·U ^-m (2) That is, lnE ₁ =−n·lnU+lnA ₁ +lnf ₁ (θ) lnE ₂ =−m·lnU+lnA ₂ +lnf ₂ (θ). However, f ₁ (θ) and f ₂ (θ) are functions of θ.

The characteristic equation of this second equation is lnE ₁ vs. lnU, lnE ₂ vs.
When shown in a diagram of lnU, it becomes as shown by the solid line in Fig. 6.

As is clear from FIG. 6, which shows the first characteristic equation as a broken line and the second characteristic equation as a solid line, the voltage E ₁ when the speeds U=u ₁ and u ₂ in the reference state, Since E ₂ is equal to the voltage E ₁ E ₂ at a certain angle θ and a certain speed U in the tilted state,
From the first and second equations, A ₁・U ₁ ^-n = f ₁ (θ)・A ₁・U ^-n A ₂・U ₂ ^-m
=f ₂ (θ)・A ₂・U ^-m u ₁ /U=f ₁ (θ) ^--1/n u ₂ /U=f ₂ (θ) ^--1
/m (3) ∴u ₁ /u ₂ =f ₁ (θ) ^--1/n /f ₂ (θ) ^--1/n (4) That is, if the equivalent velocities u ₁ and u ₂ are known, the angle θ can be found from the fourth equation, and the speed U can be found from the third equation. The characteristic equation of the third equation and the characteristic equation of the fourth equation are:
While maintaining the speed U at a constant value in the tilted state, measure the voltages E ₁ and E ₂ by changing the angle θ to various values, and calculate the equivalent voltages from the voltages E ₁ and E ₂ using the diagram in Figure 4. Find the speeds u ₁ and u ₂ , and as shown in Figure 7, u ₁ /U
It is obtained as a diagram of u ₂ /U vs. θ, and a diagram of u ₁ /u ₂ vs. θ.

Therefore, when determining the wind direction θ and wind speed U using the detection object 1, (1) Measure the voltages E ₁ and E ₂ using the voltmeters 26 and 27.

(2) Find the equivalent speeds u ₁ and u ₂ from the voltages E ₁ and E ₂ using the diagram in FIG. 4, and calculate u ₁ /u ₂ .

(3) Find the wind direction θ from u ₁ /u ₂ using the diagram of u ₁ /u ₂ versus θ in Figure 7.

(4) From the wind direction θ, use the diagram of u ₁ /U vs. θ or the diagram of u ₂ /U vs. θ in Figure 7 to calculate u ₁ /U or u ₂ /
Find U, and calculate the wind speed U from that value and the known equivalent speed u ₁ or u ₂ .

In the illustrated detection body 1 described above, the left and right heating wires 7 and 8 are arranged at a right angle, but they may be arranged at an acute angle or an obtuse angle. In short, they should be arranged non-parallel. If the heating wires 7 and 8 are arranged at an acute angle, the measurement range will be narrower, but the sensitivity will be better; if they are arranged at an obtuse angle, the sensitivity will be worse, but the measurement range will be wider. Therefore, the angle formed by both heating wires 7 and 8 is
A temperature of about 45 to 135 degrees is good.

Further, although the base body 2 has a disk shape, it may have another shape. In short, any shape is sufficient as long as it is easy to attach to the measurement location.

In addition, during the measurement, the detection object 1 was fixed at the measurement location and the wind direction θ and wind speed U were determined from the measured voltages E ₁ and E ₂ . The airflow F may hit both the left and right heating wires 7 and 8 at the same angle, the wind direction θ may be determined from the rotation angle of the detection body 1, and the wind speed U may be determined from the measured voltages E ₁ and E ₂ . In such a case, the base body 2 may be shaped to be easily rotated at the measurement location.

The above detection body for thermoelectric anemometer detects the temperature of each heating wire on both sides, which are cooled according to the direction and speed of the airflow, using each thermocouple, and detects the wind direction at the same location in the airflow. Wind speed can be measured at the same time.

In addition, unlike conventional wind vanes that measure by the zero position method in which the deflection of the pointer of the measuring instrument is zero by rotating the handle tube, in the case of unsteady airflow where the direction or speed of the airflow changes from moment to moment. It is also possible to simultaneously measure the wind direction and wind speed at the same location in the airflow moment by moment.

Furthermore, by fixing it to a rotating or moving object, it is possible to simultaneously measure the wind direction and wind speed at the same location in the airflow flowing over the surface of the object.

Furthermore, since it is composed of a base, a heating wire, and a thermocouple, it is compact. Therefore, the airflow at the measuring point is not disturbed significantly, and even when the airflow flows through a narrow space, the wind direction and wind speed at the same location in the airflow can be measured simultaneously.

Furthermore, since the temperature of each heating wire is measured based on the wind temperature, it is not affected by the wind temperature and the measurement accuracy does not deteriorate even when the temperature of the airflow changes.

Next, the detection body for a thermoelectric type wind direction, wind speed, and temperature meter of the present invention will be explained.

As shown in FIG. 8, the detecting body 31 for a thermoelectric type anemometer according to the embodiment of the present invention includes thermocouples 11 and 3 for measuring wind temperature in addition to the detecting body for the thermoelectric type anemometer.
3 and 32 are additionally provided, and the tip of a third column 32 made of chromel for a thermocouple is protruded from a position close to the second column 11 on the left side of the upper surface 3 of the base body, and the second column 32 on the left side is 11 and the third thermocouple wire 33 made of chromel wire is connected between the tips of the third column 32, and the second column 11 made of alumel on the left, the third thermocouple wire 33 made of chromel wire, and the third column made of chromel are connected. 32
The connection point 21 between the second column 11 on the left side and the third thermocouple wire 33, which has the same temperature as the air flow F, is used to measure the air temperature of the air temperature thermocouples 11, 33, and 32. The second post 11 on the left side is shared by the wind temperature thermocouples 11, 33, 32 and the wind direction/speed thermocouples 13, 9, 11, 17 on the left side. Other points are the same as the detection object 1 shown in FIG. 1, so the same reference numerals are given in FIG. 8 and the explanation will be omitted.

When using the detection body 31 of this example, as shown in FIG. One end of the thermocouple compensation conductors 35 and 36, which are alumel wire and chromel wire, are connected, and the other ends of both compensation conductors 35 and 36 are electrically insulated from each other in a thermostat 37 maintained at a constant temperature lower than the air temperature. Both compensating conductors 35 and 3 in the thermostat 37 are inserted and serve as low-temperature contacts of the air temperature thermocouples 11, 33, and 32.
An air temperature indicator 38, which is a voltmeter that measures the thermoelectromotive voltage of the air temperature thermocouple, is connected between the ends of the air temperature thermocouple. Other points are
Since this is the same as in the detection object 1 shown in FIG. 2, the same reference numerals are given in FIG. 9 and the explanation thereof will be omitted.

In the detection body 31 of the illustrated embodiment described above, the air temperature thermocouples 11, 33, and 32 are provided on the left side of the base 2, but they may be provided on the right side.

The present invention provides a high-temperature contact for measuring wind direction and wind speed, which is provided with electrically heated heating wires arranged non-parallelly on both sides of a base body, and whose temperature is the same as that of the heating wires, which are cooled according to the direction and speed of the airflow. Wind direction/velocity thermocouples with low-temperature contacts for wind temperature correction, which have the same temperature as the airflow, are placed on the base for each heating wire on both sides, and high-temperature contacts for wind temperature measurement, which have the same temperature as the airflow, are placed on the base. This is a detection body for a thermoelectric type wind direction/speed anemometer characterized by being provided with a wind temperature thermocouple.

The detection body for a thermoelectric type anemometer of the present invention detects the temperature of each heating wire on both sides, which are cooled according to the direction and speed of the airflow, using each wind direction and speed thermocouple. By detecting the temperature using a wind temperature thermocouple, it is possible to simultaneously measure the wind direction, wind speed, and wind temperature at the same location in the airflow.

In addition, unlike conventional wind vanes that measure by the zero position method in which the handle tube is rotated to zero the deflection of the pointer of the measuring instrument, this method uses unsteady airflow where the direction, speed, or temperature of the airflow changes from moment to moment. In this case, the wind direction, wind speed, and wind temperature at the same location in the airflow can be measured simultaneously and moment by moment.

In addition, by fixing it to a rotating or moving object, it is possible to simultaneously measure the wind direction, wind speed, and wind temperature at the same location in the airflow flowing on the surface of the object.

Furthermore, since it is composed of a base, a heating wire, a wind direction/velocity thermocouple, and a wind temperature thermocouple, it is compact. Therefore,
It does not significantly disturb the flow of the airflow at the measurement location, and even when the airflow flows through a narrow space, the wind direction, wind speed, and wind temperature at the same location in the airflow can be measured simultaneously.

Furthermore, when measuring the wind direction and speed, the temperature of each heating wire is measured based on the wind temperature, so it is not affected by the wind temperature and even when the temperature of the airflow changes,
Measurement accuracy does not deteriorate.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a detection body for a thermoelectric anemometer according to the present invention, and Fig. 2 is a connection circuit diagram of the detection body.
Figure 3 is a plan view of the same detection object in the standard state, Figure 4 is a line diagram of lnE ₁ vs. lnU and lnE ₂ vs. 6
The figure shows lnE ₁ vs. lnU and lnE ₂ vs. lnU in the same tilted state.
Figure 7 is a diagram of u ₁ /U versus θ for the same detection object.
This is a diagram of u ₂ /U vs. θ and a diagram of u ₁ /u ₂ vs. θ.
The figure is a perspective view of a detecting body for a thermoelectric type anemometer of the present invention, and FIG. 9 is a connection circuit diagram of the detecting body. 1: Detector for thermoelectric anemometer, 2: Substrate,
7, 8: heating wire, 9, 10: first support for thermocouple,
11, 12: Second strut for thermocouple, 13, 14: First thermocouple wire, 17, 18: Second thermocouple wire, 19,
20: High temperature contact for wind direction and speed measurement, 21, 22: Low temperature contact for wind temperature correction, 31: Detector for thermoelectric wind direction and speed anemometer, 32: Third column for thermocouple, 33: Third
Thermocouple wire, 21: High temperature contact for wind temperature measurement, F: Air flow.

Claims (1)

[Claims] 1. Electrically heated heating wires are arranged non-parallel on both sides of the base, and the temperature is the same as that of the heating wires, which are cooled according to the direction and speed of the airflow, for measuring wind direction and wind speed. A wind direction and speed thermocouple with a high-temperature contact and a low-temperature contact for wind temperature correction that is the same temperature as the airflow is placed on the base for each heating wire on both sides, and a high-temperature contact for wind temperature measurement that is the same temperature as the airflow is installed. A detection body for a thermoelectric wind direction, wind speed, and anemometer, characterized by having a wind temperature thermocouple arranged on a base.