JP2018036069A - Environmental testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environmental testing device that can conduct snowfall tests and is less subject to freezing of its spray nozzle.SOLUTION: An air conditioner 3 and a spray nozzle 10 are arranged in a test chamber 2, which is equipped with an external water supply system 20 for supplying the spray nozzle 10 with water and an external air supply system 21 for supplying the spray nozzle 10 with air. The spray nozzle 10 is a two-fluid nozzle having a water passage channel 30 and an air passage channel 31 inside. When snow is to be caused to fall in the test chamber 2, a snow fall operation is performed, in which water is sprayed in the test chamber 2 by the spray nozzle 10. When no snow is to be caused to fall in the test chamber 2, an idle operation is performed, in which the water stream flowing in the water passage channel 30 is stopped and only the air is discharged from the spray nozzle 10 by making the air pass through the air passage channel 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an environmental test apparatus that can artificially create a snowfall state and accumulate snow on a test object such as a building member, an electric wire, or a vehicle.

One of the environmental test devices is a device called an artificial climate chamber or an artificial weather chamber. The artificial climate chamber is a device that artificially creates an environment close to the natural environment. For example, it reproduces the environment of extremely cold Hokkaido or Siberia, and examines the performance and strength of the test object.
One of the artificial climate chambers artificially creates a snowy environment. In this type of artificial climate chamber, for example, a roof material of a house, a vehicle, or the like can be arranged in a test chamber, and pseudo snow can be accumulated thereon.
Hereinafter, an environmental test performed by artificial snowfall may be referred to as a snowfall test.

One method for artificially creating a snowy environment is to spray water in a low temperature environment and freeze the sprayed water droplets in the middle of falling.
As one of the environmental test apparatuses that realize this measure, there is a structure in which a spray nozzle is provided on the ceiling, the test chamber is kept at a temperature below freezing point, and water is sprayed from the spray nozzle. The sprayed water freezes while floating in the test room, and pseudo snow is generated, falls and accumulates snow.

JP 58-75678 A

However, the method of spraying water, freezing and snowing has the problem that the spray nozzle may freeze and become clogged. In particular, the spray opening of the spray nozzle may freeze and become clogged.
When water is sprayed vigorously from the spray nozzle, the spray opening is unlikely to freeze, but when the spray is stopped or interrupted, the water dripping from the spray nozzle freezes or the water remaining in the spray nozzle May freeze.

To explain the start of the snowfall test, the temperature in the test chamber is lowered prior to spraying water from the spray nozzle. Meanwhile, the spray nozzle is in a standby state without spraying water. Then, after the temperature of the test chamber reaches below freezing point, water is sprayed into the test chamber from the spray opening of the spray nozzle.
However, in the standby state, water remaining in the spray nozzle may freeze.
That is, since the environmental test apparatus performs a snowfall test or the like on a daily basis, residual water from the previous snowfall test may remain in the spray nozzle at the start of the current snowfall test. If there is residual water in the spray nozzle, when the spray nozzle is exposed to the cold air in the test chamber, the residual water may freeze, and water may not be sprayed, or the spray pattern may be distorted.

  Depending on the test conditions, snow may be intermittently applied, and spraying from the spray nozzle may be interrupted during the test. When the snowfall is interrupted, water may remain in the spray nozzle. Therefore, when spraying is interrupted and time elapses, residual water in the spray nozzle freezes, and spraying cannot be resumed or the spray pattern may be distorted.

If the spray opening of the spray nozzle freezes and becomes clogged and can no longer be sprayed, the operator must enter the test chamber and perform maintenance work to eliminate the clogging of the spray opening.
Here, when clogging of the spray nozzle occurs during the continuous test over a long period of time, the clogging eliminating operation may be very troublesome.

  That is, when the test is continuously performed for a long time, it is necessary to ensure the continuity of the test, and thus the environmental test apparatus cannot be stopped. For this reason, the worker must replace or clean the spray nozzle in an extremely cold environment.

Furthermore, the maintenance of the spray nozzle is a high place work.
In other words, in order to artificially perform snowfall, the sprayed water must be frozen during the fall to form pseudo snow. Therefore, it is necessary for the test room to secure a considerable drop margin, and the ceiling of the actual test room is 4 to 5 meters above the floor. The above-mentioned maintenance work of the spray nozzle must be carried out at such a high place, which is dangerous.

  As described above, the maintenance work for the spray nozzle needs to be performed in a state kept below the freezing point so that the snow is not melted, and is therefore a work in a low temperature environment, a high place work, and a fine manual work. . Therefore, the working environment of the operator who maintains the spray nozzle is very harsh and troublesome.

  Accordingly, an object of the present invention is to develop an environmental test apparatus that can perform a snowfall test and that is less likely to freeze the spray nozzle.

  The invention described in claim 1 for solving the above-described problem has a test chamber capable of creating a sub-freezing environment and a spray nozzle, and the spray nozzle is maintained in a state where the temperature in the test chamber is maintained below the freezing point. In an environmental test apparatus that sprays water in a test chamber, freezes water droplets in the test chamber, and artificially snows in the test chamber, the spray nozzle has a water passage channel and an air passage channel inside, This is a two-fluid nozzle that sprays water by mixing the air that has passed through the air passage with the water that has passed through the water passage, and when the snow falls in the test chamber, it passed through the water passage by the spray nozzle. When snowfall operation is performed in which water that has passed through the air passage is mixed with water and sprayed into the test chamber, and snow is not allowed to fall into the test chamber, the water flow that flows through the water passage is stopped, and the air passage Nozzle spraying only air by passing air through An environmental test apparatus for carrying out the racing operation to release from.

In the present invention, the “pseudo snowfall” includes a case where a semi-frozen ice piece such as a sleet is dropped as well as a case where a supercooled ice piece such as so-called powder snow is dropped.
In the environmental test apparatus of the present invention, a two-fluid nozzle is adopted as the spray nozzle. In the environmental test apparatus of the present invention, when the snow does not fall in the test chamber, the water flow flowing through the water passage channel is stopped, and the air is allowed to pass through the air passage channel and only air is discharged from the spray nozzle.
Therefore, even if water droplets remain in the water passage channel or the water channel and the water droplets are transmitted near the outlet of the water passage channel, the water droplets are blown off by the air blown from the air passage channel, and the spray nozzle is Does not clog.
In addition, an outlet of the water passage channel, for example, an opening portion that discharges water is covered with air jetted from the air passage channel. Therefore, the opening part that discharges water is kept warm by the air jetted from the air passage, and freezing of the jet nozzle opening is prevented.

  The invention according to claim 2 is characterized in that the air blowing operation is performed when no snow falls in the test chamber and there is a possibility that the environment in the test chamber freezes water. It is an environmental test apparatus as described in above.

  Here, the case where there is a possibility that the environment in the test room may freeze water may be a case where the environment in the test room tends to decrease and the room temperature approaches the freezing point. In addition, the case where the environment of the test room is already below freezing is included when there is a possibility of freezing water.

  The invention according to claim 3 has a supply air cooling means for cooling the air supplied to the air passage flow path, and the air cooled by the supply air cooling means is supplied to the air passage flow path during a snowfall operation. The environmental test apparatus according to claim 1 or 2, wherein air is supplied to the air passage without being cooled during the air blowing operation.

In the present invention, in the snowfall operation, the air cooled by the supply air cooling means is supplied to the spray nozzle. During snowfall operation, the temperature of the supplied air is low, so that it is difficult to inhibit the sprayed water from freezing.
In addition, although the air supplied in the snowfall operation is cooled by the supply air cooling means, it is desirable that the temperature is above the freezing point in order to prevent the spray nozzle from freezing.
On the other hand, since the air is supplied to the spray nozzle without cooling during the idling operation, the temperature of the supplied air is high. Therefore, the function of preventing the spray nozzle from freezing is high.

  Invention of Claim 4 has a supply water cooling means to cool the water supplied to the said water passage flow path, and a supply air cooling means is between the water cooled with the air and the supply water cooling means. The environmental test apparatus according to claim 3, wherein heat exchange is performed.

According to the present invention, low-temperature water can be supplied to the spray nozzle during snowfall operation. Therefore, the enthalpy of sprayed water is low, and it tends to become snow.
In the present invention, the structure is simple because heat is exchanged with the water cooled by the supply water cooling means.

  In the invention described in claim 5, the supply water cooling means has a water tank and cools water in the water tank, and the supply air cooling means is a heat exchanger installed in the water tank. The environmental test apparatus according to claim 4, wherein air is passed through the secondary side flow path of the heat exchanger.

  According to the present invention, air can be efficiently cooled.

  The invention described in claim 6 has an air heating means for heating the air, and supplies air heated by the air heating means to the air passage channel during the idling operation. 5. The environmental test apparatus according to any one of 5 above.

  In the present invention, since the heated air is supplied to the spray nozzle during the idling operation, the temperature of the supplied air is high. Therefore, the function of preventing the spray nozzle from freezing is high.

  According to the seventh aspect of the present invention, air is allowed to pass through the water passage channel at the time of at least one of the initial stage of the air-blowing operation and the air-blowing operation after the snow-falling operation is performed before the snow-falling operation is performed. An environmental test apparatus according to any one of claims 1 to 6.

  According to the present invention, residual water in the spray nozzle can be removed by air blowing through the water passage.

  The environmental test apparatus of the present invention can artificially create a snowfall state in a test chamber, and the spray nozzle is difficult to freeze. Therefore, the environmental test apparatus of the present invention has an effect of suppressing the test from being interrupted due to freezing of the spray nozzle.

It is the conceptual diagram which portrayed the environmental test apparatus of embodiment of this invention typically, and shows the outline of a test room and a piping system. It is a substance perspective view of an environmental testing device of an embodiment of the present invention. It is a piping system of the environmental test apparatus shown in FIG. 1, and shows the flow of water and compressed air during a snowfall test. It is a piping system of the environmental test apparatus shown in FIG. 1, and shows the flow of water and compressed air in a standby state. It is a piping system of the environmental test apparatus shown in FIG. 1, and shows the flow of water and compressed air in the air blow operation. It is a piping system of the environmental test apparatus shown in FIG. 1, Comprising: Another example of the flow of water and compressed air in a standby state is shown.

Hereinafter, an environmental test apparatus 1 according to this embodiment of the present invention will be described.
A conceptual display of the environmental test apparatus 1 of the present embodiment is as shown in FIG. 1, centering on a test chamber 2 (artificial climate chamber), provided with an air conditioning equipment 3 and a spray nozzle 10, and further spray nozzles An external water supply system 20 that supplies water to 10 and an external air supply system 21 that supplies air to the spray nozzle 10 are provided. For illustration purposes, only one spray nozzle 10 is shown in FIG. 1, but the actual environmental test apparatus 1 has a plurality of spray nozzles 10 as shown in FIG.

  As shown in FIGS. 1 and 2, the test chamber 2 is a space substantially sealed by a side wall 5 having a layer made of a heat insulating material, a ceiling 6 and a floor surface 7. The height from the floor surface 7 to the ceiling 6 is, for example, about 3 to 6 m. Moreover, the horizontal length between the side walls 5 which face each other shown in FIG. 2 is about 4-10 m, for example. That is, the test chamber 2 is a test space having a length and width of about 4 to 10 m and a height of about 3 to 6 m.

The environmental test apparatus 1 has a path for circulating the air in the test chamber 2 through the air conditioning equipment 3, and the test chamber 2 is provided with an air suction port 8 and an air supply port 9 as shown in FIG. It has been. As shown in FIG. 1, the air inlet 8 is in the lower part of the side wall 5, and the air supply port 9 is in the upper part of the side wall 5.
The air suction port 8 and the air supply port 9 are holes provided in the side wall 5. The air supply ports 9 are actually distributed and provided at a plurality of locations above the four side walls 5 as shown in FIG. In addition, the air supply port 9 is actually a collection of small holes, and the flow rate of air introduced from each hole is low.

As shown in FIG. 1, a spray nozzle mounting hole 11 is provided in the ceiling 6 of the test chamber 2. For illustration purposes, only one spray nozzle mounting hole 11 is shown in FIG. 1, but a plurality of spray nozzle mounting holes 11 are formed in the actual test chamber 2.
The spray nozzle mounting holes 11 are provided at equal intervals, and are arranged at a rate of 1 to 4 per 1 m ² (square meter), for example.
Spray nozzles 10 are respectively mounted in the spray nozzle mounting holes 11 provided in the ceiling 6.

  Various devices, articles, and the like to be tested are arranged on the floor surface 7 as necessary, but the depiction thereof is omitted in FIGS.

The air conditioner 3 of the environmental test apparatus 1 includes an air conditioner 12, a duct 13, and a blower 28 as shown in FIGS.
The air conditioner 12 is a device having a function of adjusting the inside of the test chamber 2 to a predetermined temperature and humidity. That is, the air conditioner 12 includes a cooler, a heater, a dehumidifier, and a humidifier (not shown).

As shown in FIG. 1, the duct 13 includes a supply side duct 13a and a suction side duct 13b. The suction side duct 13 b forms an air flow path that connects the air suction port 8 of the test chamber 2 and the air conditioner 12. The supply-side duct 13 a forms an air flow path that connects the air conditioner 12 and the air supply port 9 of the test chamber 2. That is, the test chamber 2 and the air conditioner 12 are connected in an annular shape via the supply side duct 13a and the suction side duct 13b.
As shown in FIG. 2, the supply side duct 13a actually forms a belt-like space extending along the upper part of the side wall 5 of the test chamber 2, and this belt-like space and each supply port (small hole) 9 are formed. Communicate.

  As shown in FIG. 1, the blower 28 is provided in the supply side duct 13a. When the air blower 28 is driven, the air in the test chamber 2 is sent from the air suction port 8 to the air conditioner 12 via the suction side duct 13b, and within the air conditioner 12, a predetermined temperature (for example, minus 20 degrees Celsius to minus 40 degrees Celsius). Degree). The adjusted air is discharged from the discharge port 28 a of the blower 28 and returns to the inside of the test chamber 2 through the supply side duct 13 a and the air supply port 9. That is, the air adjusted to a predetermined temperature by the air conditioner 12 is supplied into the test chamber 2 from each air supply port 9 by the blower 28 via the supply side duct 13a.

Next, the spray nozzle 10 will be described. The spray nozzle 10 is a known two-fluid nozzle, has a double tube structure as shown in FIG. 1, and has a water passage channel 30 and an air passage channel 31 inside.
That is, the spray nozzle 10 has an outer tube 32 and a liquid supply tube 33. The spray nozzle 10 is configured such that a liquid supply pipe 33 is concentrically arranged in an outer tube 32.
The liquid supply pipe 33 is hollow and functions as the water passage 30 as described above.
There is a gap between the liquid supply pipe 33 and the outer pipe 32, and the gap functions as the air passage channel 31.

  In the spray nozzle 10 employed in the present embodiment, the tip opening 35 of the liquid supply pipe 33 is opened in the outer tube 32. Therefore, the distal end opening 36 of the outer tube 32 becomes the opening end of the entire spray nozzle 10. The tip opening 35 of the liquid supply pipe 33 is narrowed down. The distal end opening 36 of the outer tube 32 is also narrowed down.

The spray nozzle 10 employed in the present embodiment is a known two-fluid nozzle, supplies water to the liquid supply pipe 33 disposed on the center side, and an air passage channel between the liquid supply pipe 33 and the outer tube 32. By supplying compressed air to 31, water is sprayed from the distal end opening 36 of the outer tube 32.
That is, water is discharged from the tip opening 35 of the liquid supply pipe 33 that is the water passage channel 30, and this water collides with the compressed air that has passed through the air passage channel 31, and is pulverized and mixed to form fine water droplets. The water that has become fine water droplets flies on the compressed air that has passed through the air passage channel 31 and is sprayed from the distal end opening 36 of the outer tube 32.

  The spray nozzle 10 is mounted in a spray nozzle mounting hole 11 provided in the ceiling 6 of the test chamber 2, and a tip portion projects from the surface of the ceiling 6 of the test chamber 2 into the test chamber 2.

Next, the external water supply system 20 that supplies water to the spray nozzle 10 will be described.
The external water supply system 20 includes a water tank 40, a pump 41, an on-off valve 42, and a water amount adjustment unit 43, which are connected in series.
The water tank 40 is a tank for storing water, and stores water so that the water level is always constant by a ball tap or the like (not shown).
A cooling device 45 such as a chiller is attached to the water tank 40, and the water temperature in the water tank 40 is maintained at a low temperature that does not freeze.
In the present embodiment, the cooling device 45 functions as supply water cooling means.

  The water amount adjustment unit 43 includes a flow rate control valve 46 and an on-off valve 47. The on-off valve 47 is specifically an electromagnetic valve, but other open valves such as a motor valve can also be used. The same applies to the other opening / closing valves shown in FIG. 1, and an electromagnetic valve is employed. However, other opening valves such as a motor valve may be used.

  The external water supply system 20 has a water tank 40 as a base end, and a pump 41, an on-off valve 42, and a water amount adjusting unit 43 are sequentially connected by piping, and a terminal is connected to the liquid supply pipe 33 of the spray nozzle 10.

  Next, the external air supply system 21 will be described. As shown in FIG. 1, the external air supply system 21 includes a compressor 50, a heating system 51 and a cooling system 53 are provided in parallel, and a pressure adjusting unit 55 is provided downstream of both.

An air heating means 56 is provided in the middle of the heating system 51. The air heating means 56 is provided with a heater 57 in the air flow path, and can raise the temperature of the passing air.
An on-off valve 58 is provided in the middle of the heating system 51.

A cooling heat exchanger 60 is provided in the middle of the cooling system 53. The cooling heat exchanger 60 is arranged in the water tank 40 described above. The air pressurized by the compressor 50 passes through the fluid flow path of the cooling heat exchanger 60. The air passing through the cooling heat exchanger 60 is cooled by cold water in the water tank 40. In this embodiment, the supply air cooling means 48 is constituted by the cooling heat exchanger 60 and the water tank 40. In the middle of the cooling system 53, an on-off valve 61 is provided.

  The pressure adjustment unit 55 includes a pressure reducing valve 62 and an opening / closing valve 64.

  The external air supply system 21 has a compressor 50 as a base end, and a heating system 51 and a cooling system 53 are connected in parallel. The pressure adjusting unit 55 is connected to the joining pipe of both, and the downstream side of the pressure adjusting unit 55 is connected to the air passage 31 of the spray nozzle 10.

In the present embodiment, there is a connection pipe 66 that further connects the external water supply system 20 and the external air supply system 21.
The connection pipe 66 branches between the open / close valve 58 of the external air supply system 21 and the air heating means 56 and is connected between the open / close valve 42 of the external water supply system 20 and the water amount adjusting unit 43. An open / close valve 67 is also provided for the connection pipe 66.

Next, functions of the environmental test apparatus 1 of the present embodiment will be described. The environmental test apparatus 1 according to the present embodiment can perform a snowfall operation and an air blowing operation.
The snowfall operation is an operation in which snow falls artificially in the test chamber 2.
In the snowfall operation, the temperature in the test chamber 2 is adjusted below the freezing point by the air conditioner 12. Then, water is sprayed from the spray nozzle 10 into the test chamber 2 in this state. As a result, the sprayed water droplets freeze in the test chamber 2 and snowfall occurs in the test chamber 2.
On the other hand, in the idling operation, the water flow through the water passage channel 30 is stopped, air is allowed to pass through the air passage channel 31, and only air is discharged from the spray nozzle 10.
This will be described below.

  When reproducing the snow cover state using the environmental test apparatus 1 of the present embodiment, the temperature in the test chamber 2 is adjusted to, for example, about minus 20 to 40 degrees Celsius by the air conditioner 12. That is, the air blower 28 is driven, and the air in the test chamber 2 is sucked through the air suction port 8 and the suction side duct 13 b and introduced into the air conditioner 12. The air introduced into the air conditioner 12 is adjusted to a predetermined temperature, then discharged from the discharge port 28a of the blower 28, and supplied into the test chamber 2 through the supply side duct 13a and the plurality of air supply ports 9. Is done.

Water is sprayed from the spray nozzle 10 into the test chamber 2 in this state.
Specifically, as shown in FIG. 3, the open / close valve 42 of the external water supply system 20 is opened and the pump 41 is driven to supply the water in the water tank 40 to the water passage 30 via the water amount adjustment unit 43. . At this time, the on-off valve 67 of the connection pipe 66 is closed as shown in FIG.
Therefore, water is supplied to the water passage 30 of the spray nozzle 10, and water is discharged from the tip opening 35 of the liquid supply pipe 33.

On the other hand, low-temperature compressed air is supplied to the air passage channel 31 of the spray nozzle 10.
Specifically, the on-off valve 61 of the external air supply system 21 is opened and the cooling system 53 is opened. The on-off valve 58 is closed and the heating system 51 is closed.
Then, the compressor 50 is driven, and compressed air is supplied to the air passage 31 of the spray nozzle 10 via the cooling system 53 and the pressure adjusting unit 55.
The air supplied to the spray nozzle 10 passes through the cooling system 53 of the external air supply system 21. Therefore, the air supplied to the spray nozzle 10 is heat-exchanged with the cold water in the water tank 40 when passing through the cooling heat exchanger 60, and has a low temperature.

When attention is paid to the tip of the spray nozzle 10, water is discharged from the tip opening 35 of the liquid supply pipe 33. Here, the water discharged from the tip opening 35 of the liquid supply pipe 33 is cooled by a cooling device 45 such as a chiller and has a low temperature.
This water collides with the compressed air that has passed through the air passage channel 31, is crushed and mixed to form fine water droplets, which are diffused by the compressed air.
The air supplied to the spray nozzle 10 during the snowfall operation has passed through the cooling system 53 and has a low temperature.
Therefore, air mixed with water cools the water droplets and promotes freezing of the water droplets.
Water droplets diffused from the spray nozzle 10 are frozen in the test chamber 2 and snowfall occurs in the test chamber 2.

Next, the idling operation will be described.
The air blowing operation is an operation performed before the snowfall test, when the snowfall is interrupted, or after the snowfall.

During the idling operation, spraying of water from the spray nozzle 10 is stopped.
Specifically, as shown in FIG. 4, the pump 41 of the external water supply system 20 is stopped and the on-off valve 42 is closed.
On the other hand, compressed air is supplied to the air passage channel 31 of the spray nozzle 10. Here, in the present embodiment, the passage path of the compressed air changes during the idling operation as shown in FIG. That is, during the idling operation, the on-off valve 61 is closed, the cooling system 53 is closed, the on-off valve 58 is opened, and the heating system 51 is opened.
Then, the compressor 50 is driven, and heated compressed air is supplied to the air passage 31 of the spray nozzle 10 via the heating system 51 and the pressure adjusting unit 55.

When attention is paid to the tip of the spray nozzle 10, water from the tip opening 35 of the liquid supply pipe 33 stops.
On the other hand, air is released from the air passage channel 31. Therefore, even if residual water drops fall from the tip opening 35 of the liquid supply pipe 33, it is blown away by the air discharged from the air passage channel 31.
In addition, the air supplied to the spray nozzle 10 during the air blowing operation has passed through the heating system 51 and is heated by the heater 57, so the temperature is high.
For this reason, the spray nozzle 10, particularly the tip opening 35 of the liquid supply pipe 33, is surrounded by warm air and is in a relatively high temperature state.
Therefore, freezing of the tip opening 35 of the liquid supply pipe 33 of the spray nozzle 10 and the tip opening 36 of the outer tube 32 is prevented.

  The environmental test apparatus 1 of the present embodiment can also perform an air blow operation. The air blow operation is an operation in which the water passage in the spray nozzle 10 is blown to remove residual water in the spray nozzle 10.

In the air blow operation, the supply of water to the liquid supply pipe 33 of the spray nozzle 10 is stopped as shown in FIG. 5, and compressed air is supplied to the liquid supply pipe 33 of the spray nozzle 10 instead.
In the air blow operation, a flow path for supplying air to the liquid supply pipe 33 of the spray nozzle 10 via the connection pipe 66 is opened, and the other flow paths are closed.
Specifically, as shown in FIG. 5, the pump 41 of the external water supply system 20 is stopped and the on-off valve 42 is closed.
On the other hand, the on-off valve 67 of the connection pipe 66 is opened, and the connection pipe 66 is opened. The on-off valve 58 of the external air supply system 21 is opened, and the on-off valve 61 is closed.

  Compressed air produced by the compressor 50 is supplied to the liquid supply pipe 33 of the spray nozzle 10 via the open / close valve 58, the open / close valve 67, and the connection pipe 66. As a result, water is discharged from a series of flow paths including the water amount adjustment unit 43 that is a part of the external water supply system 20 and reaching the end of the spray nozzle 10.

  It is desirable that the air blow operation be performed before snowfall operation or after the end of snowfall operation. Moreover, you may perform an air blow operation in the above-mentioned air blow operation. FIG. 6 shows the flow of compressed air when the air blow operation is performed during the air blow operation.

It is desirable that the air blowing operation is performed when snow does not fall in the test chamber 2 and the environment in the test chamber 2 may freeze water. In other words, it is desirable to perform the idling operation when there is a risk that the spray nozzle 10 may be frozen by the cold air.
Specifically, it is desirable to start the idling operation when the temperature in the test chamber 2 becomes below freezing point.
Further, when the temperature in the test chamber 2 tends to decrease as in the initial operation, it is desirable to start the air blowing operation before it becomes below freezing point.
In the case where snow falls intermittently in the test chamber 2, it is desirable to continue the air blowing operation during the standby period when the snowfall is stopped.

In the embodiment described above, the external air supply system 21 is divided into two systems, and the air heating means 56 is provided on one (heating system 51). However, the air heating means 56 is not essential to the present invention and may be omitted.
Similarly, the cooling device 45 provided in the water tank 40 and the cooling heat exchanger 60 installed in the water tank 40 are not essential.

In the present embodiment, the supply air cooling means is a cooling heat exchanger 60 arranged in the water tank 40, and cools the air passing through heat exchange with the cold water in the water tank 40. That is, in this embodiment, cold water supplied to the water passage 30 of the spray nozzle 10 is used as a refrigerant for cooling the air.
However, the present invention is not limited to this configuration, and a method such as cooling the air with an air conditioner or making the evaporator of the refrigeration circuit adjacent to the air flow path may be adopted.
Further, the supply air cooling means itself may be omitted.

DESCRIPTION OF SYMBOLS 1 Environmental test apparatus 2 Test room 3 Air conditioning equipment 10 Spray nozzle 20 External water supply system 21 External air supply system 30 Water passage channel 31 Air passage channel 32 Outer tube 33 Liquid supply tube 35 Tip opening 36 Tip opening 40 Water tank 48 Supply Air cooling means 45 Cooling device 51 Heating system 56 Air heating means 60 Cooling heat exchanger

Claims (7)

It has a test chamber capable of creating a sub-freezing environment, and a spray nozzle. Water is sprayed from the spray nozzle into the test chamber with the temperature inside the test chamber kept below freezing, and water drops are frozen in the test chamber. In an environmental test device that artificially snows in the test chamber,
The spray nozzle is a two-fluid nozzle that has a water passage passage and an air passage passage inside, and sprays water by mixing the air that has passed through the water passage passage with the air that has passed through the air passage passage. Yes,
When snowing in the test chamber, the snowfall operation of spraying water into the test chamber by mixing the air that has passed through the air passage channel with the water that has passed through the water passage channel by the spray nozzle,
An environmental test apparatus that performs an air blowing operation that stops water flow through a water passage channel, allows air to pass through the air passage channel, and discharges only air from the spray nozzle when snow does not fall in the test chamber.   The environmental test apparatus according to claim 1, wherein the air blowing operation is performed when there is no possibility of snow falling in the test chamber and there is a possibility that the environment in the test chamber may freeze water. Supply air cooling means for cooling the air supplied to the air passage channel, and supply the air cooled by the supply air cooling means to the air passage channel during snowfall operation,
The environmental test apparatus according to claim 1 or 2, wherein air is supplied to the air passage without cooling in the air blowing operation.   Supply water cooling means for cooling water supplied to the water passage channel, wherein the supply air cooling means performs heat exchange between the air and water cooled by the supply water cooling means. The environmental test apparatus according to claim 3, wherein   The supply water cooling means has a water tank and cools the water in the water tank, and the supply air cooling means is a heat exchanger installed in the water tank, and the secondary side flow of the heat exchanger The environmental test apparatus according to claim 4, wherein air is passed through the road.   6. The environmental test according to claim 1, further comprising air heating means for heating air, wherein air heated by the air heating means is supplied to the air passage channel during the idling operation. apparatus.   The air is allowed to pass through the water passage channel at least one of the initial stage of the air blowing operation and at the time of the air blowing operation before the snowfall operation is performed, and after the snowfall operation is performed. 6. The environmental test apparatus according to any one of 6.

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