JPS60151536A - Testing method of smoke diffusion model - Google Patents

Abstract

PURPOSE:To measure the concentration distribution of gas in a diffusion area quantitatively by placing tapes on the surface of a relief model supported rotatably in a measurement wind tunnel wherein a wind diffused by a rotatable plate type air current controller flows at a desired speed, and allowing a discoloration reagent with which the tapes are impregnated to react with tracer gas. CONSTITUTION:A fan 5 is rotated and the air current controller 6 is put in operation. The air current controller 6 is a rotatable plate type arranged perpendicularly, and this is operated to regenerate the wind which flows at the desired speed on specific air current condition (degree of disorder), thereby diffusing mixed gas discharged from a chimney model 2. Relief models 3 and 4 are supported rotatably at the downstream side and adjusted to set a specific wind direction. The diffused gas discharged from the chimney model 2 contacts the tape 12 on the surface of the relief model 4 of discolor the discoloration reagent with which the tape 12 is impregnated, so the diffusion range of the gas is known from the discoloration state.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for qualitatively and quantitatively testing the state of diffusion of gas emitted from chimneys and buildings using a horizontal method.

In order to prevent air pollution caused by exhaust gases emitted from power plants, chemical factories, etc., it is necessary to qualitatively assess the diffusion status of these polluting exhaust gases in the atmosphere and on the ground surface.

In addition, it is necessary to obtain data that can be quantitatively understood and used to determine the most effective and economical chimney installation location, height, exhaust gas emission rate, etc., depending on location conditions, scale, etc.

As a means of gathering such data, calculation methods,
There are two methods: on-site testing and model testing.

As calculation methods, Sutton's theoretical formula, the board formula, and the British Met Office's empirical formula have been published, but none of them take into account the influence of topography. or,
Recently, there have been cases in which the effects of topography on these equations have been confirmed through numerical analysis using computers, but all require verification through experiments.

The field test method cannot be tested until after the actual chimney has been constructed, and conducting tests in a wide area with complex topography would be extremely costly and labor intensive.

Furthermore, it is a matter of time to freely select the chimney height, wind direction, etc., and data can only be obtained at the - point.

Conventionally, tests using a model involve discharging gas from a horizontal chimney and observing the diffusion of the gas with the naked eye. Understanding the concentration distribution is nearly impossible, especially when the topography is complex.

This invention is provided to eliminate the drawbacks of the conventional model testing method as described above and to qualitatively and quantitatively grasp the exhaust gas diffusion situation with the naked eye or by recording means. The wind direction is determined by rotating a topographical model rotatably supported within the measurement barrel of a wind tunnel in which wind at a desired speed is disturbed by a flexible plate-shaped airflow control device, and a tape is placed on the surface of the model. A tracer gas is discharged from a predetermined position within the measurement barrel, and the diffusion region is measured by reacting the tracer gas with the color-changing reagent applied to the tape.Next, the concentration distribution of the tracer gas within the obtained diffusion region is determined. This is a smoke diffusion test method that measures quantitatively.

Therefore, according to the method of the present invention, the concentration is measured in advance in the area where smoke diffuses, so that the efficiency of concentration measurement, that is, the measurement is not carried out within the range where there is no diffusion ( This means that efficient testing can be performed even in terrain where complex diffusion phenomena occur.

The method of the present invention will be explained below with reference to the drawings.

FIG. 1 is a conceptual diagram showing the qualitative test of the present invention, in which 1 is a measurement cylinder surrounded by transparent walls and a ceiling;
2 is a chimney, 3 and 4 are so-called topographic models such as structure and topographic models, and 50 is a rotary plate arranged on the wind tunnel floor 51, on which a chimney model 2, a horizontal structure 3, and a topographic model 4 are installed. It is. Note that this rotary plate 50 is located on the leeward side of an airflow control device 6, which will be described later. 52 is a rotating plate action bearing, 53 is a support for the bearing 52, and 54 is a rotating plate 50.
Rotating shaft attached to the bottom, 55.56 is a pulley,
57 is a drive source (motor) that rotates the rotating shaft 54; 58
59 is a controller for the drive source 57, and 59 is a controller for the drive source 57 to the rotating shaft 5.
This is a power transmission belt to 4.

5 is a fan that sends air into the measurement body 1, and 6 and 7 are airflow control devices for reproducing actual airflow conditions. The airflow control device 6 is a rotatable hole plate-like device vertically disposed throughout the flow path in the measurement chamber 1.

A plurality of slits are formed in the wing-shaped diaphragm 6-1. Reference numeral 6-2 denotes reinforcing disks to which the diaphragm is attached, which are provided above and below the diaphragm 6-1. The rotating shaft 36-4 of the diaphragm 6-1 is a bearing 6-3 that supports the diaphragm rotating shaft 6-3. 6-5 is a guide plate for the reinforcing disk 6-2, 6-6 is a worm foil, 6-7 is a pulse motor,
6-8 is a controller, and 6-9 is a signal cable. 6-1
0 indicates the deflection direction of the diaphragm 6-1.

Note that this airflow control device 6 may be provided horizontally throughout the flow path.

The airflow control device 7 is a plate-shaped device placed on the floor of the measurement chamber and is attached horizontally to the floor so as to be perpendicular to the wind.

Reference numeral 8 designates a cylinder that compresses and stores gas that has been mixed and adjusted to a predetermined gas concentration; 9 and 10 designate a mixed gas flow meter and a mixed gas passage; and 11 designates a flow rate adjustment valve that adjusts the amount of the mixed gas from the cylinder 8.

12 is a string-like tape impregnated with a color-changing reagent, and 13 is a thumbtack for fixing the tape 12 to the surface of the topographical model 4.

15 is a record bag N (still camera, ν, T, R, etc.) for recording the discoloration status of the indicator 12.

4 to 6 are conceptual diagrams showing the quantitative test of the present invention, and numeral 16 in the figures is a gas sampling tube made of a thin tube of glass, stainless steel, or the like.

17 is a test tube, 18 and 19 are thin tubes inserted into the test tube 17, and the thin tube 18 is immersed in the test liquid 21, while the thin tube 19 is not immersed. 22 is the gas sampling pipe 16
23 is a tube that communicates the thin tube 19 with the gas suction device, 24 to 30 are each member of the gas suction device 25, and 26 and 27 are manometers with relatively widely different diameters. Thin tubes 24-1.24-2.24-3.24 each have a defined volume and are arranged in the vertical direction.
-4 is connected. 28 is a header connected to the thin tube 24-4, 29 is a water tank, and 30 is a header 28
This is a flexible pipe that connects the water tank 29 and the water tank 29.

First, in FIG. 1, first, the controller 58 and the drive source 57
The drive source 57 is actuated by applying an electric signal to the drive source 57 . Drive source 57
The power from pulley 56. The power is transmitted to the pulley 55 and the rotating shaft 54 by the transmission belt 59, and the rotating shaft 54 is rotated.

As a result, the one-turn plate 55 rotates, and the horizontal mold 4 placed on the nine-turn plate 55 is set in a predetermined wind direction.

Since the bearing 52 is provided, the rotary plate 55 is maintained horizontally and can rotate smoothly, allowing the terrain model to be set in any wind direction.

On the tape 12 installed on the surface of the topographical model 4,
It is impregnated with an indicator such as Huff'om Thymol Blue and a color changing reagent consisting of an alcohol solution and starch paste.

Meanwhile, a predetermined amount of a tracer gas having the property of changing the color of this color-changing reagent, such as a mixed gas of air and ammonia gas, is passed through the chimney model through the passage 10 while monitoring the mixed gas flow meter 9 and adjusting the flow rate a regulating valve 11. 2 into the measuring cylinder 1.

The fan 5 is rotated and the airflow control device 6 is activated. The action of the airflow control device 6 is to drive the pulse motor 6-7 by the control 6-8, and transfer the rotational power of the pulse motor 6-7 to the diaphragm rotation shaft 6-3 via the worm wheel 6-6.
tell. As a result, the diaphragm 6-1 swings as shown by the arrow 6-10, creating a highly turbulent airflow. The diaphragm 6-1 is vertically supported by a bearing 6-5. In addition, the opening of the airflow condition (turbulence degree) is with diaphragm 6-1.
Since this is performed based on the swing width and angular period of the diaphragm 6-1, data such as the swing width and angular period of the diaphragm 6-1 that can reproduce predetermined airflow conditions are input into the controller 6-8 in advance. Furthermore, the vibration period of the diaphragm 6-1 can be set both regularly and irregularly.

When wind is passed through the measurement cylinder 1 to achieve predetermined airflow conditions (wind speed distribution, turbulence distribution, etc.), the mixed gas discharged from the chimney model 2 is diffused and impregnated with the discoloration reagent attached to the surface of the terrain model 4. Upon contact with the tape 12, the color changing reagent changes color from orange-yellow to yellow-green and then to indigo. This makes it possible to know the diffusion range of the mixed gas discharged from the chimney model 2.

Furthermore, as the discolored area expands over the course of 9 hours (usually about 1 to 2 minutes), the situation can be observed with the naked eye or with a recording device such as a camera.
5, it is also possible to qualitatively estimate the concentration distribution of the mixed gas.

As the gas discharged from the chimney model, in addition to the alkaline gas such as ammonia mentioned in the above embodiments, acidic gases such as sulfur dioxide gas and hydrogen chloride can also be used.

Next, a case will be described in which the concentration distribution on the mounting surface of the tape 12 is quantitatively determined.

First, the fan 5 and the airflow control device 6 are used to maintain the same predetermined airflow conditions in the measurement chamber 1 as in the case of FIG. 1, and gas is discharged from the chimney model 2 in the same manner.

As a result, the mixed gas similarly diffuses within the measurement barrel 1 and reaches the gas sampling tube 16 that opens on the surface of the topographical model within the diffusion range determined in the qualitative test.

Thereafter, a fixed amount of gas is sucked from the gas sampling tube 16, but in this case the water level in the gas suction device is at the uppermost thin tube 24-1.

When the water tank 29 is gradually moved downward in this state, the water in the suction pipes 24 to 28 is gradually discharged through the flexible pipe 30.

As a result, the water level in the thin tube 24-1 also gradually moves downward, causing the first member 25. It moves downward with the thin tube 24-2. Then, the pressure within the member decreases, the pressure within the test tube 17 via the tube 23 decreases, and the diffused state of the mixed gas is suctioned from the gas sampling tube 16 via the tube 22.

In this case, if the volume of one member 25 is A, 26 is B, and 27 is C, if the water level after suction falls to the thin tube 24-2, only A will be sucked from the gas sampling hole 16 and the thin tube 24- If it drops to 3, the suction amount is A + B, and the capillary is 2.
In the case of up to 4-4, the suction amount is A+B+C, and the suction amount can be selected depending on the diffusion concentration of the mixed gas.

According to this method, the area in which gas emitted from a chimney, etc. diffuses can be qualitatively determined cheaply and quickly by a horizontal test under conditions that reproduce the airflow characteristics with large turbulence in the field. Efficient distribution measurement experiments can be carried out in the most necessary range based on the diffusion range of exhaust gas and time changes in the state of discoloration.

Therefore, basic data necessary for preventing air pollution caused by chimney exhaust gas etc. can be provided extremely effectively.

[Brief explanation of drawings]

FIGS. 1 to 3 are diagrams for explaining the qualitative test method of the method of the present invention, and FIGS. 4 to 6 are diagrams for explaining the quantitative test method. 1. Measurement cylinder, 2; 3; 4. Terrain model. 6...Airflow control device, 12...Tape, 16...Gas sampling tube, 50...Rotating plate 5i Continuation of figure 2, page 1 ■Inventor: Hatao Ide

Claims (1)

[Claims] The wind direction is determined by rotating a terrain model rotatably supported in the measurement barrel of the wind tunnel, through which wind at a desired speed is disturbed by a rotatable plate-shaped airflow control device, and a tape is placed on its surface. The tracer gas is discharged from a predetermined position in the measurement cylinder, and the diffusion region is measured by reacting the tracer gas with the discoloration reagent applied to the tape. Next, the concentration of the tracer gas in the obtained diffusion region is determined. A smoke diffusion test method characterized by quantitatively measuring distribution.