JP2597255B2 - Heating control device of regenerative heater in blow-out type wind tunnel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is generally used for performing aerodynamic tests at a high Mach number such as a hypersonic wind tunnel. It relates to a heating control device of a heater in a blow-out type wind tunnel provided with a heater for preventing
In particular, the present invention relates to a heating control device for a regenerative heater.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a general structure of a blow-out type wind tunnel having a heater.
Is an air storage tank that stores high-pressure compressed air. 3 is a pressure regulating valve,
The high-pressure compressed air in the air storage tank 1 is guided through the high-pressure conduit 2 and is reduced to a constant pressure in accordance with the valve opening adjusted by an external signal. 4 is a heater, 5 is a collecting cylinder, 6
Is a nozzle, and 7 is a measuring unit. The compressed air decompressed to a constant pressure by the pressure regulating valve 3 passes through the heater 4, the collecting cylinder 5, the nozzle 6 and the measuring unit 7 into the inside of the vacuum tank 8. Released to Here, a is a shutoff valve for shutting off the outlet of the heater 4, and b is a cooler for cooling the air that has exited the measuring unit 7. Air heating by the heater 4 is as follows.
Usually, at about 800 ° C. to 1000 ° C., it prevents air from liquefying due to a decrease in air temperature due to acceleration (see Aerospace Laboratory Report TR-116).

In the above-mentioned wind tunnel, since only the compressed air stored in the air storage tank 1 allows ventilation and all the air after ventilation is discharged into the vacuum chamber 8, the ventilation time is typically several seconds. It is limited to a very short time of about several tens of seconds, during which all measurements must be completed.
Further, after the compressed air inside the air storage tank 1 is released by ventilation to increase the pressure in the vacuum tank 8, the air storage tank 1 is refilled for a retest and the vacuum tank 8 is again filled with a predetermined vacuum. Requires a large amount of time on the order of several hours. Further, in the wind tunnel for performing the aerodynamic test at such a high Mach number, since the Mach number of the airflow is determined by the shape of the nozzle 6, no special control device is provided, and the nozzle is not provided in accordance with the required Mach number. It is customary to replace 6.

[0004] The pressure control device in the wind tunnel controls the total pressure of the collecting cylinder 5, that is, the stagnation point pressure to a predetermined value.
It has the function of adjusting the opening of the pressure regulating valve 3, and in order to stabilize the air flow inside the wind tunnel in a short time in order to extend the test time even a little, in addition to the accuracy to guarantee the reproducibility of the test. High-speed response is required.

[0005] By the way, the heater in the conventional blow-out type wind tunnel is configured as shown in FIG. In the figure, reference numeral 10 denotes a heater outer shell, in which a heat storage body 11 such as a spherical alumina pebble is filled, and has a structure in which the heat storage body 11 is supported by a metal grid 12. 13 is a gas burner installed on the upper part of the heater 4,
The combustion gas after heating the heat storage body 11 and storing the heat is discharged from the inlet 15 of the heater 4 to the outside. Reference numeral 14 denotes an outlet of the heater 4, and the high-temperature air introduced from the inlet 15 and pressure-controlled is discharged to the collecting cylinder 5 and the nozzle 6 at the next stage.

Next, the operation of the heater 4 having the above configuration will be described. First, the shutoff valve a at the outlet 14 of the heater 4
(FIG. 4) is closed, and combustion air and a fuel gas supplied from a separately provided combustion blower are introduced into a gas burner 13 at an upper portion, and ignited to heat and heat the regenerator 11 to heat the combustion gas. It is discharged from the inlet 15 of the vessel 4 to the outside. At the time of ventilation, the air stored in the air storage tank 1 and pressure-adjusted by the pressure regulating valve 3 is introduced into the inlet 15, and heat is exchanged while passing through the heat storage body 11. 14 to the collecting cylinder 5 and the nozzle 6. In this case, the temperature of the heated air is determined by the temperature of the upper part of the heat storage body 11, and sufficient air heating cannot be performed unless the temperature of the upper part of the heat storage body 11 is set to a predetermined value.

By the way, the weight of the heat storage body 11 inside the heater 4 is all supported by the grid 12 below the heater 4, but the strength of the metal grid 12 decreases when the temperature becomes high. Since the weight of the heat storage body 11 cannot be supported, there is an operational restriction that the temperature of the grid 12 must be kept below an allowable value. Such a heater 4
Is heated by the gas burner 13 at the uppermost part, the temperature distribution of the heat storage body 11 usually has the highest temperature at the uppermost part, and the temperature decreases toward the lower part. In this case, there is no problem because the temperature of the grid 12 can be suppressed to an allowable range and the upper temperature of the heat storage body 11 can be increased.

[0008] However, if the heater 4 is heated and left as it is, it cools from the upper part. Therefore, even if the temperature of the uppermost part decreases, the internal temperature does not decrease so much. The highest temperature region is generated at the time. When reheating is performed using the upper gas burner 13 in this state, the highest temperature region moves to the lower portion of the heater 4 and approaches the lower grid 12, and the temperature at the uppermost portion rises to a predetermined value. Prior to this, the temperature of the grid 12 will exceed the tolerance.

[0009]

In the above-described conventional heating control apparatus for a regenerative heater, the temperature distribution of the heat storage body 11 inside the heater 4 changes, and a maximum temperature region is generated in an intermediate portion. No special measures have been taken against the rise in the temperature of the grid 12 that occurs as a result of this, and the driving safety has only been maintained by paying sufficient attention among those involved in some operations. .

As described above, when a maximum temperature region is generated in the intermediate portion, cooling air is introduced from the inlet 15 of the heater 4 to lower the temperature of the heater 4 and shift the maximum temperature region upward. It is customary to employ means for causing this to occur. Since the introduction of such cooling air results in a loss of heat energy stored in the heater 4, it is desirable to minimize the introduction. However, conventionally, no measures have been taken in this regard. Therefore, in a conventional driving method that relies on the driver's attention, a high degree of skill is required for the determination, and the above determination is erroneously made by a person who has no experience, for example, while the highest temperature region remains in the middle part. Reheating may occur, which may cause damage to the grid 12 and even the heater 4 itself.

In order to avoid the above situation,
If the heater 4 is left for a long time, it is cooled excessively in order to shift the highest temperature region in the middle to the upper part.
Not only the heat loss becomes excessive, but also the reheating time becomes longer, and the use efficiency of the wind tunnel tends to deteriorate.

The present invention has been made in view of the above circumstances, and can prevent damage to the grid and the heater even by reheating when the temperature distribution of the heat storage body inside the heater is poor. It is an object of the present invention to provide a heating control device of a regenerative heater in a blow-out type wind tunnel in which a safe operation can be performed even by a non-expert.

It is another object of the present invention to minimize the amount of cooling air when improving the temperature distribution.

[0014]

According to a first aspect of the present invention, there is provided a heating control device for a regenerative heater in a blow-out type wind tunnel according to a first aspect of the present invention, which measures a vertical temperature distribution of the regenerative heater. A plurality of temperature detectors that output as temperature signals and determine whether or not the temperature distribution inside the heater is within a heatable range based on the temperature signals output from these temperature detectors, and permit the result to be heated. A temperature distribution determining unit that outputs a signal, and when the heating permission signal output from the temperature distribution determining unit can be heated, the heating operation of the heater is enabled, and when the heating is not possible, the heating operation of the heater is performed. And a combustion control device that makes it impossible.

According to a second aspect of the present invention, there is provided a heating control device for a regenerative heater in a blow-out type wind tunnel, wherein a plurality of temperature detectors for measuring a temperature distribution in a vertical direction of the regenerative heater and outputting the measured temperature signal. A temperature distribution determining unit that determines whether or not the temperature distribution inside the heater is within a heatable range based on the temperature signals output from the temperature detectors, and outputs the result as a heating permission signal. When the heating permission signal output from the temperature distribution determining unit cannot be heated, the cooling operation of the heater by the cooling air is enabled, and when the heating is possible, the cooling air control device stops the cooling operation of the heater. It is provided with.

The cooling air control device may be configured to introduce high-pressure air in an air storage tank by using a pressure regulating valve.
A configuration may be adopted in which combustion air supplied from a combustion blower for heating the heater is guided to the inlet 15 of the heater.

The temperature distribution determining section includes a reference temperature generator for outputting a reference temperature signal corresponding to the temperature signal, and a comparator for comparing each of the temperature signals with the reference temperature signal and outputting a determination signal. It is preferable to use a device that includes a determination signal output from the comparators and a heating determination unit that determines whether or not to perform heating by inputting a determination signal.

Further, the reference temperature generator preferably calculates and outputs a reference temperature corresponding to the uppermost temperature signal from a temperature detector that outputs a temperature signal at the uppermost portion of the heater. .

[0019]

According to the first aspect of the present invention, when the heater is left for a long time, a maximum temperature region is generated in an intermediate portion of the heater, and the vertical temperature distribution becomes unsuitable for reheating. The temperature distribution determination unit determines that heating is not possible, and sets the heating permission signal to heating impossible. In this case, even if an ignition operation is performed on the combustion control device for reheating, the heating permission signal is interlocked and reheating is not performed.

Further, according to the second aspect of the present invention, the cooling air control device can be cooled in a state where the temperature distribution determining unit determines that heating is not possible and the heating permission signal is set to the heating disabled.
Then, in this state, when the temperature distribution is improved by the cooling air, the temperature distribution is improved and the reheating becomes possible.At this time, the cooling operation by the cooling air is automatically stopped, and excessive cooling of the heater is performed. Is prevented. Furthermore, even when the temperature distribution changes during heating and reheating is not possible, the heating permission signal is disabled by the temperature distribution determination unit, so that the heater is not further heated.

[0021]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a heating control device for a regenerative heater in a blow-out type wind tunnel according to one embodiment of the present invention. In FIG. Since they are the same, the corresponding parts are denoted by the same reference numerals and their detailed description is omitted.

In FIG. 1, reference numeral 20 denotes a heating control device, which comprises a temperature distribution judging section 21, a combustion control device 22, and a cooling air control device 30. The temperature distribution determination unit 21 includes temperature detectors T1 to T5 sequentially installed from the upper part to the lower part of the heater 4, and the temperature detectors T1 to T5.
ＴT5 are output and compared with a reference temperature distribution, and the temperature signals t1ｔt5 are output.
Is below the reference temperature distribution, the heating permission signal S1
Can be heated, and if any one of the temperature signals t1 to t5 is equal to or higher than the reference temperature distribution, the heating permission signal S
1 cannot be heated. Further, the combustion control device 22 includes:
In response to the above-described heating permission signal S1, if heating is possible, the main valve 16 of the gas supply pipe 17 can be opened, and if heating is not possible, the main valve 16 is closed.

That is, in the combustion control device 22, when the heating permission signal S1 is heatable, the main valve 16 of the gas supply pipe 17 is opened by heating operation by the operation of the heating operation device 23, and the gas supply pipe 17 is opened by fire. It has a function to close the main valve 16, and when the heating permission signal S1 cannot be heated,
It has a function of closing the main valve 16 of the gas supply pipe 17 regardless of the operation of the heating operation device 23. That is, the heating permission signal S1 is output from the heating operation device 23 in the combustion control device 22.
Acts as an interlock signal for the operation of.

FIG. 2 is a block diagram showing a specific structure of the temperature judging section 21. In FIG. 2, reference numeral 100 denotes a reference temperature generator, which generates a temperature distribution as a reference in the vertical direction of the heater 4. I do. Reference numerals 101 to 105 denote comparators, which are temperature signals t1 to t1 of the heater 4 output from the temperature detectors T1 to T5.
t5 and the reference temperature signals t1s to t5s output from the reference temperature generator are input, and the two are compared in magnitude. These comparators 101 to 105 output determination signals d1 to d5 by the calculation of the following equation (1).

[0025]

(Equation 1)

Reference numeral 106 denotes a heating determination unit,
When the determination signals d1 to d5 output from the input signals 105 to 105 are input and all of the determination signals d1 to d5 are ON, that is, when all of the temperature signals t1 to t5 are equal to or less than the corresponding reference temperature signals t1s to t5s, heating is performed. Enable signal S1
N, that is, heating is enabled, and conversely, when any of the determination signals d1 to d5 is OFF, that is, when any of the temperature signals t1 to t5 is equal to or more than the corresponding reference temperature signal t1s to t5s, the heating permission signal S1 is turned OFF. That is, heating is not possible.

Next, in FIG. 1, the cooling air control device 30 receives the heating permission signal S1 and turns off the cooling air when the heating permission signal S1 is OFF, that is, when the temperature distribution of the heater 4 cannot be heated. It is introduced from the inlet 15 of the heater 4. Conversely, when the heating permission signal S1 is ON, the introduction of the cooling air is stopped.

In the above embodiment, the pressure regulating valve 3 is used as a cooling air control device, and by partially opening the pressure regulating valve 3, a part of the high-pressure air stored in the gas storage tank 1 is used. I do. That is, when the heating permission signal S1 is OFF, the high-pressure air stored in the air storage tank 1 is depressurized by opening the pressure regulating valve 3 to a preset opening, and then introduced into the heater 4, whereby the heater 4 When the heating permission signal S1 is turned on when the temperature distribution in the vertical direction inside the
The pressure regulating valve 3 is fully closed to automatically shut off the supply of the cooling air. By using the pressure regulating valve 3 and a part of the high-pressure air stored in the air storage tank 1 as the cooling air control device in this manner, a separate blower or the like for supplying cooling air becomes unnecessary, and the whole is economical. Can be configured.

In the above embodiment, the temperature detectors T1 to T1
Since the vertical position of the heater 4 at T5 is fixed, the reference temperature generator 100 outputs the temperature signals t1 to t5.
It is only necessary to output five fixed set values corresponding to.

FIG. 3 is a block diagram showing a configuration of a reference signal generator according to another embodiment of the present invention. In FIG. 3, the same parts as those of the embodiment shown in FIG. Therefore, their description is omitted. In FIG.
0 is a reference signal generator, and a temperature signal t at the top of the heater 4
1 is input and the reference temperature signal corresponding to the other temperature signals t2 to t5 is set to a value corresponding to t1, and the following calculation is performed. Reference temperature signal _{t is = α i · t1 +} β i (i = 1~5) ...... (2)

[0031] Thus, by the reference temperature signal t _IS be corresponded to a top temperature, even cooling condition of the heater 4 is anything reliably detect the occurrence of the highest temperature region in the middle part be able to. Further, the correspondence between the reference temperature signal _tis and the uppermost temperature t1 is not limited to the above equation (2), but may be, for example, a numerical table based on the design value of the heater 4 or a more detailed equation.

In the above embodiment, the comparator 1
As 01-105, it is assumed to carry out the calculation of the above equation (1) is not limited to this calculation, there may be differences in criteria O N and OFF.

[0033]

Each of the temperature signals t1 to t5 is
Because it is for measuring the temperature distribution in the vertical direction of, for example, using a plurality of temperature detectors having the same vertical position and different horizontal positions, the average of the posted signals of those temperature detectors A temperature signal representing the temperature distribution in the vertical direction such as the temperature and the maximum temperature may be obtained by calculation, and the same effect as in the above embodiment can be obtained.

Further, in the above embodiment, five temperature detectors are used, but the number is not limited. In general, the more the number is increased, the more precise the judgment can be made. Further, in the above-described embodiment, the pressure regulating valve 3 which is a part of the wind tunnel equipment is used as the cooling air control device. However, a dedicated blower may be used instead, and the cooling air control device is installed in the vicinity. A blower, for example, a combustion blower used when heating the heater 4 may be used.

Further, the heating permission signal S1 is not input to the combustion control device 22 or the cooling air control device 30, but a display and an alarm are generated based on the heating permission signal S1. Even when the air control device 30 is operated, the same effects as those of the above embodiment can be obtained.

[0037]

As described above, according to the first aspect of the present invention, the heater is allowed to stand for a long time, the highest temperature region is generated in the middle of the heater, and the heater is not suitable for reheating. When the temperature distribution becomes, the temperature distribution determination unit determines that heating is not possible, disables the heating permission signal, and disables the reheating operation. In addition to being able to perform highly reliable operation, it is possible to reliably prevent damage to the grid and the heater itself due to reheating while the highest temperature region is generated in the middle part.

According to the second aspect of the present invention, when the cooling air is introduced to improve the temperature distribution in the vertical direction of the heater, the heating can be performed with the improvement of the temperature distribution. The cooling operation can be stopped automatically, minimizing the amount of cooling air used, preventing unnecessary cooling, that is, excessive cooling, reducing heat loss and fully using the entire wind tunnel. Can be enhanced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a heating control device of a regenerative heater in a blow-out type wind tunnel according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a specific configuration of a temperature determination unit.

FIG. 3 is a block diagram showing a configuration of a reference signal generator of a heating control device of a regenerative heater in a blow-out type wind tunnel according to another embodiment of the present invention.

FIG. 4 is a general configuration diagram of a blow-out type wind tunnel.

FIG. 5 is a sectional structural view of a heater in a conventional blow-out type wind tunnel.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 air storage tank 3 pressure regulating valve 4 regenerative heater 5 collecting cylinder 6 nozzle 20 heating control device 21 temperature distribution determination unit 22 combustion control device 23 heating operation device 30 cooling air control device 100 reference temperature generator 101 to 105 comparator 106 Heating determination unit T1 to T5 Temperature detector

Claims (6)

(57) [Claims] 1. Heating control of a regenerative heater in a blow-out type wind tunnel in which high-pressure compressed air stored in an air storage tank is passed through a pressure regulating valve and heated by a regenerative heater to ventilate a nozzle. In the apparatus, a plurality of temperature detectors that measure the temperature distribution in the vertical direction of the regenerative heater and output as a temperature signal, and the temperature distribution inside the heater is heated by the temperature signals output from the temperature detectors A temperature distribution determining unit that determines whether the temperature is within a possible range and outputs the result as a heating permission signal, and a heating operation of the heater when the heating permission signal output from the temperature distribution determining unit can be heated. And a combustion control device for disabling the heating operation of the heater when the heating cannot be performed. 2. A heating control of a regenerative heater in a blow-out type wind tunnel in which high-pressure compressed air stored in an air storage tank is passed through a pressure regulating valve and heated by a regenerative heater to ventilate a nozzle. In the apparatus, a plurality of temperature detectors that measure the temperature distribution in the vertical direction of the regenerative heater and output as a temperature signal, and the temperature distribution inside the heater is heated by the temperature signals output from the temperature detectors A temperature distribution determining unit that determines whether the temperature is within a possible range and outputs the result as a heating permission signal, and a heater using cooling air when the heating permission signal output from the temperature distribution determining unit cannot be heated. And a cooling air control device for stopping the cooling operation of the heater when heating is possible, and a heating control device for the regenerative heating device in the blow-out type wind tunnel. 3. The heating control device for a regenerative heater in a blow-out type wind tunnel according to claim 2, wherein the cooling air control device is configured to introduce high-pressure air in an air storage tank using a pressure regulating valve. 4. The cooling air control device is configured to use a combustion blower for heating a heater.
Control device of regenerative heater in blow-out type wind tunnel. 5. A reference temperature generator, wherein the temperature distribution determining section outputs a reference temperature signal corresponding to a temperature signal, and a comparator, which compares the temperature signals with the reference temperature signal and outputs a determination signal. 5. A heating control device for a regenerative heater in a blow-out type wind tunnel according to any one of claims 1 to 4, further comprising: a heating determination unit that receives a determination signal output from the comparators to determine whether to perform heating. . 6. The reference temperature generator according to claim 5, wherein said reference temperature generator calculates and outputs a reference temperature corresponding to an uppermost temperature signal from a temperature detector which outputs a temperature signal at an uppermost portion of the heater. Heating control device of regenerative heater in blow-out type wind tunnel.