JPH0563746B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hot wire anemometer and a method for measuring gas components and flow velocity using the same, and in particular to simultaneously measuring wind velocity and wind temperature and gas analysis. The present invention relates to a hot wire anemometer capable of measuring the velocity of the anemometer and its measurement method.

[Prior Art] In boilers, heat treatment furnaces, incinerators, etc., wind speed and temperature measurements and gas analyzes are performed inside the furnace, flue, etc. in order to control combustion, exhaust gas, and the like. FIG. 3 is a schematic block diagram showing the equipment configuration of a boiler as an example of equipment on which such wind speed and wind temperature measurements and gas analysis are performed.

Referring to FIG. 3, combustion gas generated by burning fuel such as heavy oil inside boiler 30 flows in the direction shown by the arrow. First, the _NOx contained in the combustion gas is removed by the denitrification device 40. after that,
By passing this combustion gas through the desulfurization device 50, sulfur contained in the combustion gas is removed. Further, this combustion gas passes through a dust collector 60 to remove soot and dust contained in the combustion gas, and then reaches a flue 70. The combustion gases then flow out into the atmosphere through the chimney 80.

Before the combustion gas that has been subjected to the predetermined processing as described above flows out into the atmosphere, that is, the flue 70
Inside, the flow velocity and wind temperature of the combustion gas are measured and the components are analyzed. This is boiler 30
This is to perform combustion management and exhaust gas management, such as whether or not combustion is occurring completely within the combustion chamber. As shown in FIG. 3, this measurement is performed by inserting the probes 2a, 2b, 2c into the flue 70. For example, the probe 2a for wind speed measurement is inserted from position A in the flue 70, and the probe 2b for gas analysis is inserted into the flue 70.
By inserting the probe 2c from position B in the flue 70, and further inserting the probe 2c for wind temperature measurement from position C in the flue 70, the wind speed and temperature in the flue can be measured. A component analysis of the combustion gas is performed. Thus, conventional wind speed measurement and gas analysis are performed using separate probes located at different locations within the flue. This is because the device for wind speed measurement and the device for gas analysis are configured separately. Alternatively, the probe 2a for wind speed measurement, the probe 2b for gas analysis, and the probe 2c for wind temperature measurement may be inserted alternately into the same position of the flue 70, for example, position A. Therefore, measurements of wind speed and temperature and gas analysis may be performed.

[Problems to be Solved by the Invention] Measured values of wind speed and wind temperature and gas analysis values are related in terms of management analysis, and are preferably measured at the same location. However, conventional wind speed measurement and gas analysis are performed by inserting a probe for wind speed measurement and a probe for gas analysis at different positions. Therefore, there was a problem that both measurements were inaccurate.

Furthermore, in conventional wind speed measurement and gas analysis, probes for measuring wind speed and wind temperature and probes for gas analysis may be inserted alternately at the same location. However, according to this method, although the positions where both measurements are made are the same, there is a problem that deviations occur due to changes in the measured values over time, making the measurements inaccurate. It was hot.
Furthermore, even when the probes are inserted alternately at the same location, it is difficult to always specify the insertion location at the same location, and there is a problem in that inaccuracies due to deviations in measurement locations cannot be resolved.

Furthermore, even when measuring wind speed and wind temperature and gas analysis at three different locations, or when measuring three by inserting probes alternately in the same location, wind speed and temperature Since the measurement and gas analysis devices are constructed separately, there is a problem in that they are inconvenient to handle.

Therefore, this invention was made to solve the above-mentioned problems, and it is possible to measure wind speed and wind temperature and gas analysis at the same time at the same location, and it is easy to handle. The purpose of this invention is to provide a hot-wire anemometer and a method for measuring gas components, flow velocity, and wind temperature.

[Means for Solving the Problems] A hot wire anemometer according to the invention measures the temperature of the airflow in a protective tube that is placed in the airflow to be measured and has an inlet window and an outlet window for the airflow to pass through. By arranging a temperature sensor that measures temperature and a heat radiation sensor that is kept at a higher temperature than the temperature of the airflow, and controlling the temperature difference between the temperature sensor and the heat radiation sensor to be kept constant, This is a hot wire anemometer designed to measure air flow velocity and wind temperature. This hot wire anemometer has the following features. A gas inlet of a gas inlet pipe for inhaling a part of the air flow for gas analysis is located within the protection tube and in a measurement area where a temperature sensor and a heat radiation sensor are located.

Gas composition and flow velocity using this hot wire anemometer,
In the method of measuring wind temperature, the measurement area is maintained normally by jetting a predetermined gas toward the measurement area from the gas inlet when not measuring. When measuring flow velocity and wind temperature, gas components are simultaneously analyzed by inhaling a portion of the airflow from the gas inlet.

[Operation] In the present invention, the gas inlet of the gas inlet pipe for gas analysis is arranged in the measurement area where the temperature sensor and heat radiation sensor for measuring the flow velocity of the airflow are located. Further, the gas inlet is provided within the protection tube through which the airflow passes. Therefore, the gas inlet and the sensor of the hot wire anemometer are provided at substantially the same position within the protection tube. Therefore, at the same time that the flow velocity of the same air flow to be measured passing through the protection tube is measured by the sensor of the hot-wire anemometer, the same air flow is being measured from the gas inlet of the gas inlet pipe provided in the protection tube. The gas components are analyzed by inhaling the gas.

In addition, in this invention, when not measuring, from the gas inlet of the gas inlet pipe for gas analysis,
A predetermined gas is ejected toward the measurement area.
Therefore, the inside of the suction pipe and the area around the sensor portion of the hot wire anemometer can be kept clean. Therefore,
Deterioration of measurement accuracy due to contamination of the gas inlet or sensor portion can be prevented.

[Example] FIG. 1 is a diagram showing a schematic configuration of an apparatus for measuring wind speed and gas analysis using a hot wire anemometer according to the present invention. Figure 2 shows the first
1 is a schematic cross-sectional view schematically showing a probe portion of a hot wire anemometer used in the apparatus shown in the figure; FIG. An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

Referring to FIG. 1, a hot wire anemometer probe 2 is provided within the flue in a gas flow 1 to be measured. The probe 2 is inserted into the flue by providing an insertion port in the flue side wall 14 and heat insulating wall 15 that constitute the flue. Further, the probe 2 is fixed to the side wall of the flue via a flange 12 and a flue side flange 13. A terminal box 9 is provided at the end of the probe 2 outside the flue. The sensor portion of the hot wire anemometer is connected to the hot wire anemometer instrument section 24 via this terminal box 9. A gas suction pipe provided inside the probe 2 for component analysis of combustion gas is connected to a connecting pipe 18 via a probe-side valve 19. This connecting pipe 18 is branched into a gas suction system and a gas supply system via a three-pronged valve 20. In the gas suction system, a suction pump 22 and a motor 23 for driving the suction pump 22 are provided to suction a certain amount of gas. The inhaled gas is analyzed by a gas analyzer 25 provided via an analyzer-side valve 21. On the other hand, the gas supply system is provided with a purge gas source 29 such as a cylinder connected to the supply gas pipe 26 via a pressure control valve 27 and a valve 28 .

The configuration of the probe portion of the hot wire anemometer used in the device configured as described above will be explained.
Referring to FIG. 2, the heat radiation sensor 3 consists of a thin tube with a heating resistance wire provided inside. By passing a heating current through this resistance wire, the heat radiation sensor 3
is kept higher than the temperature of the gas stream 1 to be measured. A temperature sensor 4 is provided to measure the temperature of the gas flow 1. This heat radiation sensor 3
and the temperature sensor 4 are connected to a terminal box 9 via a lead wire 8 provided inside the protection tube 6. Inside the terminal box 9, this lead wire 8 is connected to each of the connection terminals 10. A lead wire 11 extending from the terminal box 9 is connected to an anemometer instrument section 24. In the circuit provided in the anemometer instrument section 24, a temperature higher than the temperature of the gas flow 1 is applied to the heat radiation sensor 3 with a certain temperature difference.
Current is controlled. By converting this current value into a wind speed signal, the wind speed value is determined by the anemometer instrument section 24.
pointed to.

Further, inside the probe 2, a gas sampling pipe 16 is attached together with a heat radiation sensor 3 and a temperature measurement sensor 4 with heat-resistant cement 5. Protection tube 6
A part of the gas flow 1 that enters through the inlet window 7a provided at the inlet window 7a and exits the outlet window 7b is sucked in through the inlet port 17. This inhaled gas is inhaled into the gas analyzer 25 through the connecting pipe 18 connected to the gas sampling pipe 16. If the inhaled gas is under pressure, it is possible to collect the gas by simply opening and closing the valve 19, as shown in FIG. However, if the gas is not under pressure, the suction pump 22
A certain amount of gas is inhaled by driving the . The gas analyzer 25 analyzes O ₂ , CO, NO _x ,
The specified analytical equipment is configured depending on the type of gas to be analyzed, such as _SOx . Note that the analyzer side valve 21 is used to adjust the amount of gas to be analyzed. Furthermore, during gas intake, the three-pronged valve 20 is set to open toward the gas analyzer 25 side.

As described above, inside the probe 2, the heat radiation sensor 3, the temperature sensor 4, and the gas sampling tube 16 for gas component analysis are installed. For gas flows, wind speed and gas composition can be measured simultaneously. Therefore, it becomes possible to data-process the values of wind speed, wind temperature, and gas component values, which are related to each other, at the same time. Furthermore, since the sensor for wind speed measurement and the gas sampling tube for gas analysis are integrated into the probe, it is easy to handle and it is possible to perform wind speed measurement and gas analysis at the same time. A device capable of this can be constructed.

In addition, as shown in FIG.
By opening to the gas supply system side, purge gas can be sent out using the gas sampling pipe 16. This purge gas is put into a purge gas source 29, and compressed air, nitrogen, etc. are used. The purge gas blown out from the suction port 17 serves to keep the inside of the gas sampling pipe 16 and the surrounding areas of the heat radiation sensor 3 and temperature measurement sensor 4 of the anemometer clean. By blowing out the purge gas during non-measurement periods, deterioration of measurement accuracy due to contamination such as soot and dust in the flue can be prevented.

That is, by switching the three-pronged valve 20 so that it is open to the gas supply system side when not measuring, the gas introduced into the purge gas source 29 is controlled by the pressure control valve 27 via the valve 28 to an appropriate level. Adjusted to pressure. This purge gas reaches the probe 2 via the three-pronged valve 20 and the connecting pipe 18. Thereafter, the purge gas is ejected from the suction port 17 and flows out from the outlet window 7b of the protection tube 6 into the gas flow. This prevents soot and dust from entering the gas sampling pipe 16. Further, it is possible to prevent the gas flow from flowing into the protective tube 6 to some extent, and it is possible to prevent soot and dust from adhering to the sensor portion as much as possible. Furthermore, by appropriately changing the shape and direction of the discharge port, it is also possible to spray the purge gas onto the surface of the sensor portion to blow away soot and dust that tends to adhere to the surface of the sensor portion. Furthermore, by increasing the pressure of the purge gas and blowing it out,
It is also possible to remove a certain amount of soot and dust attached to the surface of the sensor portion.

In this way, during measurement, wind speed and temperature measurements and gas component analysis can be performed simultaneously at the same location, and by constantly blowing out purge gas when not measuring, the area around the sensor area and gas sampling This makes it possible to keep the inside of the pipe clean.

Note that when investigating the distribution of wind speed, wind temperature, and gas components by measuring them at multiple points, the probe 2 has multiple windows 7a and 7b, and multiple sensors and suction sensors corresponding thereto. A mouth may be provided.

[Effects of the Invention] As described above, according to the present invention, it is possible to measure wind speed, wind temperature, and gas components simultaneously at the same location. It becomes possible to simultaneously perform various flow rates, combustion analyses, etc. Furthermore, since the probe for wind velocity measurement and the probe for gas analysis have an integrated structure, their handling becomes very simple.

Furthermore, since it is possible to keep the measurement area clean when not measuring, measurement accuracy does not deteriorate and it is possible to always perform accurate measurements.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of an apparatus for gas component analysis and flow velocity measurement using a hot wire anemometer according to the present invention. FIG. 2 is a schematic sectional view schematically showing a probe portion of the hot wire anemometer used in FIG. 1. FIG. 3 is a block diagram showing the overall configuration of a boiler as an example of a combustion apparatus for explaining a conventional method for measuring gas components and flow rates. In the figure, 1 is a gas flow, 2 is a probe, 3 is a heat radiation sensor, 4 is a temperature sensor, 6 is a protection tube, 16
17 is a gas sampling pipe, 17 is a suction port, 26 is a supply gas pipe, and 29 is a purge gas source. In addition, in each figure,
The same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A temperature sensor for measuring the temperature of the airflow, placed in the airflow to be measured and inside a protection tube having an inlet window and an exit window for the airflow to pass through, and a temperature sensor for measuring the temperature of the airflow. By arranging a heat radiation sensor that is kept at a higher temperature and controlling the temperature difference between the temperature sensor and the heat radiation sensor to be kept constant, the airflow velocity and wind temperature can be measured. In the hot wire anemometer, the gas inlet of the gas inlet pipe for inhaling a part of the air flow for gas analysis is located within the protection tube,
A hot wire anemometer, characterized in that the temperature sensor and the heat radiation sensor are placed in a measurement area. 2. A method for measuring gas components, flow velocity, and wind temperature using the hot-wire anemometer according to claim 1, comprising jetting a predetermined gas from the gas inlet toward the measurement area when not measuring. Afterwards,
A method for measuring gas components and flow velocity, wherein the measurement area is kept clean, and when measuring the flow velocity and wind temperature, a part of the airflow is inhaled from the gas inlet, thereby simultaneously analyzing the gas components.