JPS61189430A - Testing device for gas diffusion - Google Patents

Abstract

PURPOSE:To obtain a diffusion testing device for detecting the change of gas diffusion state corresponding to the topography and the wind direction and a wind speed and collecting data preventing environmental pollution by providing a means for controlling the exhausting volume of tracer gas, in a gas diffusion test due to the wind direction of a model landform. CONSTITUTION:A turn table 5 to be freely rotatable pivoting a vertical rotary shaft 7 is formed on the center of a floor surface 4 of a measuring room 3 of a horizontal air duct, a model landform 6 is set up on the turn table 5 and a funnel model 3 is set up through a shaft 7. A fixed volume of tracer gas is discharged from a gas bomb 19 to the funnel model 3 by a flow rate control device 28. Plural gas intake ports 15 are formed on prescribed positions of the model landform 6 and connected to sampling pipes 16 through flexible pipes respectively to a analyze respective intake gas through a gas suction device 17. The wind direction and wind speed data of a proposed place for construction are inputted to a computer 10 and the air capacity of an air blower 1, the rotational angle of the turn table 5 and the exhausted volume of tracer gas 14 are controlled by a control device 20 to detect the gas diffusing state previously and to utilize the data for the prevention of environmental pollution.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a gas diffusion test device.

[Conventional technology]

Smoke emitted from chimneys and tunnel exhaust stacks, heat emitted from cooling towers, etc., spreads on the wind, but conventional methods are difficult to simulate such diffusion phenomena in the natural world in a wind tunnel in a laboratory. , along with a model of a chimney, mountains, rivers, and buildings in the vicinity of the chimney are placed in the wind tunnel as so-called model terrain, and a special gas is discharged from the model chimney to flow wind inside the wind tunnel. The spread of gas is observed and measured by staining tests, suction through traverse, and gas analysis.

In this case, conventionally, in order to accurately simulate the changing wind direction and wind speed, a model topography is placed in the wind channel of the wind tunnel as shown in the vertical cross-sectional view of Figure 2, and the model is made rotatable. Gas diffusion tests have been conducted in which the temporal distribution of the wind direction and wind speed are set in advance, and the model is rotated based on the temporal distribution of the wind direction.

That is, in the figure, a turntable 5 that rotates around a vertical rotation axis 7 is provided at the center of the floor surface 4 of a measurement chamber 3 of a wind tunnel into which wind 2 generated by a blower 1 and rectified into a steady flow is blown. , its upper surface coincides with the floor surface 4, a chimney model 13 is established at or near the center of the turntable 5, and a model terrain 6 such as a model building is arranged on the upper surface of the turntable 5.

An annular support member 8 along the outer circumference of the lower surface of the turntable 5
is provided protrudingly, and a roller pivotally supported at its lower end rolls along a circular track 9, and the gap between the floor surface 4 and the turntable 5 is sealed to prevent near leakage, and the turntable 5 is driven by a drive motor 11Vc. It rotates via a speed reducer and drive roller 12.

Further, the tracer gas in the gas cylinder 19 is released from the model chimney 13 in a constant amount controlled by the flow control device 18Vc, and a large number of gas inlets 15 are provided in the model terrain 6 on the tarp 5. These are connected to gas sampling pipes 16 via flexible tubes, which are further connected to a gas suction device 17 and used for suction and analysis of the tracer gas 14 discharged from the model chimney 13.

The wind 2 blowing over the model terrain 6 assembled on the turntable 5 is determined as follows. That is, the direction and speed of the wind blowing during a day at the site where the chimney is located or planned to be constructed is observed, a moral chart as shown in Figure 3 is created, and this data is input into the computer 10. The control device 20 is converted to reproduce this wind direction and wind speed.
The signals from the air blower 1 and the drive motor 111C are transmitted via lead wires 21 and 22, and the rotation angle of the turntable 50 and the wind speed 2 are adjusted.

The figure shows the frequency distribution in 16 directions, the solid line is the frequency of the wind direction, and the dotted line is the average wind speed that occurs in that wind direction, for example, for a day of 30 minutes (1,800 seconds). To test gas diffusion, we create wind 2 in the wind tunnel at a practical speed where 1z on the outer circumference of the turntable corresponds to 18 seconds, and turntable 5 is rotated 360 degrees/1
It rotates by 6 = 22.5 degrees and maintains that position for a time corresponding to the degree in the moral chart in the same figure, and during this time it maintains the average wind speed shown by the dotted line.

However, in such a gas diffusion test device, the topography around the exhaust gas outlet differs at each point, so it is necessary to rotate the model topography as described above to examine the gas diffusion state. The device has also been used to simulate changes in wind direction, but in a gas diffusion test from a factory chimney built on the coast, as shown in the fourth factor diagram, environmental and test conditions were It is quite different from the picture.

That is, in the case of FIG. 4, a model land area 6a with a coastline and an ocean area 6b without any protrusions are placed on a turntable 5 installed in a measurement chamber 3 surrounded by a wind tunnel side wall 3a. , the tracer gas 14 discharged from the model chimney 13 in the wind 2 indicated by the arrow spreads to the ocean area 6b.

In the conventional gas diffusion test, the amount of tracer gas 14 discharged is adjusted to a constant amount, but the amount discharged to the ocean where there is no pollution problem and the amount released to urban areas and farmland where pollution is accustomed to occur are different. (The workload of factories and power plants varies, and the composition of exhaust gas is not the same, so it is important to control these in relation to the wind direction.) becomes.

[Problem that the invention seeks to solve]

The present invention was proposed in view of the above circumstances, and an object of the present invention is to provide a gas diffusion test device that changes the amount of tracer gas discharged depending on the wind direction.

[Means for solving problems]

To this end, the present invention mounts a wedge-shaped terrain on a rotatable turntable provided in a horizontal wind cylinder, discharges tracer gas from a tracer gas exhaust pipe protruding above the model terrain, and various types of the turntable. The gas diffusion test device is configured to measure the diffusion of tracer gas at a rotation angle of .

[Function] With this configuration, it is possible to obtain a gas diffusion test device that changes the amount of tracer gas discharged depending on the wind direction.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view thereof.

In the above figure, the same symbols as in Fig. 2 indicate the same parts as in the same figure, and the tracer gas emission control device is a control device 2 connected to a computer 10 that inputs local weather data.
0, a flow rate control device 28 connected to the control device 20 via a lead wire 25, and a flow meter 26 with a transmitter inserted into a tracer gas pipe 29 that guides the tracer gas 14 from the tracer gas cylinder 19 to the model chimney 13. It is composed of an electric flow control valve 27.

In such a device, when the turntable 5 is rotated in response to a signal from the control device 20 so as to obtain a predetermined wind direction, the tile also receives a command for the amount of gas discharged corresponding to the wind direction via the lead wire 25. The opening degree of the electric flow control valve 27 is adjusted based on the signal transmitted to the flow rate control device 28 and fed back from the flowmeter with transmitter 26, and a preset relationship between the wind direction and the gas flow rate is maintained.

According to this type of VC, the wind direction and allowable amount of exhaust gas can be known before construction at power plants and garbage incinerators that use only the same type of fuel, and in factories where exhaust gas components differ depending on the work, the wind direction and the amount of exhaust gas can be known before construction. By knowing the relationship, it is possible to prevent pollution.

In addition, in the above embodiment, the output of the blower is variable,
It is also possible to measure the distribution state of the diffusion of the tracer gas by moving the tracer gas discharge pipe in the vertical direction depending on the wind direction and/or wind speed.

〔Effect of the invention〕

In short, according to the present invention, a model terrain is mounted on a rotatable turntable provided in a horizontal wind cylinder, a tracer gas is discharged from a tracer gas exhaust pipe protruding above the model terrain, and the turntable is In a gas diffusion test device that measures the diffusion of tracer gas at various rotation angles of a The present invention is extremely useful industrially because it provides a gas diffusion test device that allows the amount of gas to be varied.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional view showing a known gas diffusion test device, Fig. 3 is a wind rose diagram of the model terrain of Fig. 2, and Fig. 4 is a plan view showing a model topography around a factory on the coast. 1... Blower, 2... Wind, 3... Measurement room, 3a.
... Rotating axis, 8... Supporting member, 9... Circular orbit, 10
... Computer, 11 ... Drive motor, 12 ... Drive roller, 13 ... Model chimney, 14 ... Tracer gas, 15 ... Gas inlet, 16 ... Gas sampling pipe, 17... Gas suction device, 18... Meter, 19... Tracer gas cylinder, 20.20a.
...Control device, 21.22...Lead wire, 23...
Local weather data, 25...Lead wire, 26...Flow meter with transmitter, 27...Electric flow control valve, 28...
Flow rate control device, 29...tracer gas pipe

Claims (1)

[Claims] A model terrain is mounted on a rotatable turntable provided in a horizontal wind cylinder, and tracer gas is discharged from a tracer gas discharge pipe protruding above the model terrain, and the turntable is A gas diffusion test device configured to measure the diffusion of tracer gas at various rotation angles, the device comprising a tracer gas discharge amount control means for controlling the amount of tracer gas discharged.