JPS5939645Y2 - Flow velocity measuring device for rotating objects such as air conditioning fans - Google Patents

Description

[Detailed description of the invention] The present invention is capable of accurately and continuously measuring the flow velocity of airflow generated by a rotating body such as an air conditioning fan during operation, and scientifically investigates the hydrodynamic properties of the rotating body. There are many flow velocity measurement devices that contribute to improving performance by elucidating this issue.

In order to reliably know the performance of an air-conditioning fan, especially the air volume, it is necessary to accurately measure the flow velocity, and a hot wire anemometer has been widely used as a flow velocity measuring device.

This hot-wire anemometer uses a thin platinum wire that is heated through an electric current and exposed to an air flow to remove heat and lower its temperature, which reduces electrical resistance to measure the flow velocity. , it has the advantage of being highly sensitive at relatively low speeds and having good followability even when the wind speed changes rapidly.

However, there are various difficulties in directly attaching a hot wire probe that uses a platinum wire as a detection element to the blades of a rotating body, so conventionally a duct was installed in conjunction with the fan, and the air flow path inside the duct was Because a hot wire probe was installed, the performance of the fan itself could not be directly measured.
It was inevitable that the measured values would have an error of 1 iJe.

On the other hand, although it has been adopted in some cases to attach a hot wire probe directly to the blade of a rotating body, since the measuring parts such as amplifiers and recorders are stationary devices, there is a risk of slippage when making a wired connection. A relay device such as a ring must be used, and as a result, not only does noise occur at the relay device and the reliability of the measurement data decreases, but the structure becomes complicated by attaching the slip ring to the rotating body. However, this causes an increase in power and further increases the shaft length, resulting in various drawbacks such as generation of vibration and noise.

The present invention has been devised in order to improve the conventional flow rate measuring devices in view of the fact that they all have many problems. A battery used for a power source such as an air conditioning fan is fixed to a rotating body such as an air conditioning fan in a manner that can withstand centrifugal force, while a receiving section consisting of a receiver and a recorder that wirelessly receives radio waves from the transmitter is removed from the rotating body. The structure is made by disposing it at an appropriate location on other members.

Hereinafter, the device of the present invention will be further explained in detail based on an example shown in the accompanying drawings.

Fig. 1 is a 70-chart of an example of a flow velocity Okita device, which consists of a transmitting section A and a receiving section B, and uses a so-called non-contact method to exchange electrical signals between the two sections wirelessly. The basic structure is

The transmitter A is fixed to a rotating body, such as a rotating part of an air conditioning fan, in a manner that can sufficiently withstand centrifugal force, while the receiver B is installed at an appropriate location in a stationary system, excluding the rotary body.

The transmitting section A includes a hot wire probe 1 that uses a hot wire 9 such as a thin platinum wire as a flow velocity detection element, a preamplifier 2 that amplifies and converts the electrical signal of the probe 1 into a voltage of a desired level, and a transmitting antenna 5 made of, for example, a small ferrite. Transmitter 4 including coil
A battery 3 used as a power source is a small mercury battery, for example, and a hot wire probe 1 is attached to a fan blade 10 at a position where the blade 10 can be welded to the generated air flow line. The preamplifier 2, battery 3, and transmitter 4 are selected and fixed, and the preamplifier 2, battery 3, and transmitter 4 are fixed to the rotating body of the fan, either integrally with the hot wire probe 1 or separately, in a centrifugal force-resistant structure.

On the other hand, the receiving section B is installed in a stationary system member other than the rotating body, such as an operation panel, and the receiving section B is installed in a stationary system member other than the rotating body, such as a receiver 7 including a receiving antenna 6, for example, a ferrite core, an electromagnetic oscilloscope, a synchronizer, etc. It consists of a recorder 8, and the receiving antenna 6 is directed to the transmitting antenna 5 by selecting an appropriate location where there are no radio interference between them.

Next, the method of measurement using the measuring device having the above-mentioned structure will be explained. When the platinum wire 9 is heated by passing an electric current through it, and the air flow is made to flow approximately at right angles to the platinum wire 9, the platinum wire 9 is cooled and the resistance increases. is the helicopter, and at the moment when this heat exchange is balanced, 1
The relationship 2-βme7+C holds true.

However, j: current, v: wind speed, β and C: constants. Therefore, by measuring the electrical value corresponding to the change in electrical resistance, it is possible to determine the flow velocity V, which is normally used by the preamplifier 2. After being amplified to a signal level of 1, the transmitter 4 converts the signal into a frequency-modulated or amplitude-modulated radio signal, and radiates it into the atmosphere from the transmitting antenna 5.

This radiated radio wave signal is input to the receiver 7 via the receiving antenna 6, and after being demodulated, it is sent to the recorder 8.
Flow velocity and direction are recorded.

Here, since the air flow generated by the air conditioning fan is normally not a regular flow but a turbulent flow, it is necessary to obtain the flow velocity vector-wise in order to improve measurement accuracy.

When measuring turbulent flow, if the turbulence is not isotropic, such as airflow near a wall or flow very close to the surface of an object placed in the gas, the fluctuation components in each direction in the fluid It is necessary to measure 1.7 at a angle of 17 degrees for the instantaneous values u, V, and W of .

These measurements can be made using an X-type probe, a two-channel recording device, and a sum and difference calculator.

By installing the two hot wires of the X-type probe at 45 degrees with respect to the direction of the mainstream, each direction component can be separated and measured.

Next, to show a specific example of attaching the transmitter A to a rotating body, as shown in FIG.
are firmly attached with adhesive or tape, and the transmitting antenna 5 is fixed to the side end plate of the rotor 11, while the preamplifier 2, battery 3, and transmitter 4 are coaxially integrated with the fan shaft 12. It is fixed to , and famous instruments 1 to 5 are connected by wire.

However, the present invention is not limited to the above specific example, and the transmitting antenna 5 can also be fixed to the mounting disc 13, and the famous devices 2, 3.4 can be integrated and made into a resin mold. It is often made with a heat-resistant and moisture-resistant structure, and is used as a masterpiece 2, 3.
Of course, it is also a preferable embodiment to consider that the rotational balance is achieved by separately arranging the mounting discs 4 separately on the mounting disc 13, and various modified installations are possible.

Accordingly, the installation example shown in FIG. 2 has the advantage that the testing work is greatly facilitated because only the hot wire probe 1 needs to be attached, repositioned, and removed.

As clarified from the above explanation, the device of the present invention has a hot wire probe 1 that uses a hot wire such as a thin platinum wire as a flow velocity detection element.
, a transmitter A including a preamplifier 2, a transmitter 4 including a transmitting antenna 5, and a battery 3 used to power the devices 1, 2.4, a receiver 7 button including a receiving antenna 6, and a recorder 8. The transmitting section A has a hot wire probe 1 fixed to a blade section 10 of a rotating body such as an air conditioning fan rotating in the air so as to be able to come into contact with the air flow line, and ,
The preamplifier 2, transmitter 4, and battery 3 are fixed at appropriate locations on the rotating body and connected by wire, while the receiving section B is fixed at appropriate locations on other members other than the rotating body. The hot wire probe 1 is installed on the blade portion 10 so that the recorder 8 can record the flow velocity of the rotating body converted by the electric signal value corresponding to the change in the electric W resistance using the hot wire probe 1. Therefore, the flow velocity can be directly measured, the recorded data is accurate, and the flow velocity of the rotating body can be known with high precision.

In addition, a small hot wire probe 1, a preamplifier 2, a battery 3
Since the transmitter 4 is attached to the rotating body separately from the receiving unit B, the installation work is simple and can be easily attached to any rotating body, and furthermore, noise caused by slip rings etc. Since it does not use any members that may cause the occurrence, it has various excellent effects such as improving the reliability of measurement data, and is truly suitable as a general-purpose device.

[Brief explanation of drawings]

Each figure shows an example of the device of the present invention, and FIG. 1 is a flowchart of the device, and FIG. 2 is a perspective view schematically showing the installation state of the receiving section. A... Transmitting section, B... To received sound 1... Hot wire probe, 2... Preamplifier, 3... Battery, 4... Transmitter, 5... Transmitting antenna, 6... ...Receiving antenna, 7
...Receiver, 8...-Recorder

Claims (1)

[Scope of utility model registration request] A transmitting section A comprising a hot wire probe 1 using a hot wire such as a thin platinum wire as a flow velocity detection element, a preamplifier 2, a transmitter 4 including a transmitting antenna 5, and a battery 3 used as a power source for the containers 1, 2.4. , a receiver B including a receiver 7 including a receiving antenna 6, and a recorder 8, and the transmitter A transmits a hot wire blow 71 to a blade part 10 of a rotating body such as an air conditioning fan rotating in the air. The preamplifier 2, the transmitter 4, and the battery 3 are fixed at appropriate locations on the rotating body and are connected by wire, while the receiving section B is installed at an appropriate location on a member other than the rotating body, so that the recorder 8 can record the flow velocity of the rotating body converted by the electric signal value corresponding to the change in electrical resistance by the hot wire probe 1. A flow velocity measuring device for a rotating body such as an air conditioning fan, characterized in that: