JP5843240B2 - Wet snow generation method and wet snow generation apparatus - Google Patents

Description

  The present invention relates to a wet snow generation method and a wet snow generation apparatus, and more specifically, when transporting dry snow on a stream using a flow path, each dry snow is attached to the inner surface of the flow path. The present invention relates to a wet snow generation method and a wet snow generation device that can efficiently flow out from a flow path as a wet snow having a desired water content.

2. Description of the Related Art Conventionally, an environmental test room has been used for placing a complete model vehicle indoors, setting various natural environments and weather conditions, and collecting and analyzing loads on the vehicle as data.
As an example, we simulate snowstorms with artificial snow in an environmental test room, blow off the snowstorms toward the vehicle, and deal with problems such as problems caused by snow in the engine room and icing problems such as freezing of suspension parts. Things have been done.

For this reason, an environmental test room has a wind tunnel of a space enough for a vehicle to be arranged and blowing a snowstorm toward the vehicle, and a snowstorm generating device.
The snowstorm generator is simulated by an ice making machine that produces flaky ice pieces, an ice breaker that breaks the produced flaky ice pieces into ice particles of a predetermined particle size, and ice particles of a predetermined particle size that are crushed ice A pipe that conveys the artificial snow into the wind tunnel, and a blowing nozzle that is installed at the tip of the pipe and blows out toward the front of the vehicle.
According to such an environmental test room, it is possible to perform an environmental test simulating natural environment and weather conditions by blowing a snowstorm toward a vehicle in a wind tunnel using a snowstorm generator.

At this time, in order to perform an appropriate and effective environmental test, it is necessary to simulate a snowstorm in a natural state. In particular, from the viewpoint of reproducing the adhesion of the snowstorm to a vehicle, the temperature and particle size of the snow constituting the snowstorm Furthermore, it is important to generate desired wet snow by adjusting the water content as the snow quality while securing the amount of snow necessary for the test.
On the other hand, in the wind tunnel where the vehicle is placed, there is a restriction that the distance between the vehicle and the air flow outlet is short (about 1 to 2 meters), and a natural snowstorm is simulated between these short distances, Need to spray on the vehicle.

In this regard, as disclosed in Patent Document 1, the conventional snowstorm generator is configured to prevent dry snow from being generated from the viewpoint of preventing artificial snow from adhering to the inside of the device before the snowstorm is blown toward the vehicle. The balloon had been wet and snowy outside the device before reaching the vehicle.
More specifically, as shown in FIG. 8, a water injection nozzle 124 for injecting water is provided between the air outlet 122 installed in front of the air outlet 120 in the wind tunnel and the vehicle, and the air is blown out from the air outlet 122. Then, water was sprayed from the water spray nozzle 124 to dry snowstorm 123 that was simulated by the low-temperature airflow 121 from the air blowing port 120, thereby making it wet and snowy.

However, such wet snow making technology has the following technical problems.
First, even if the moisture content of the entire snowstorm is equivalent to that of wet snow in the natural state, there are various dry snows that make up the snowstorm, those that are too wet and those that are insufficiently wet. The dry snow itself is not wet.
Secondly, the dry snow constituting the snowstorm is only wetted by the water sprayed on its surface, and is different in nature from wet snow in the natural state.
From the above, the conventional wet snow making technology cannot simulate natural wet snow, so it is difficult to conduct an appropriate and accurate environmental test when evaluating the adhesion of wet snow-like snowstorms to vehicles. is there.

In this regard, Patent Document 2 discloses a wet snow making technique in which a dry air is transported toward the outflow opening by being carried on a transport airflow at a predetermined speed or more in the flow path, and upstream of the outflow opening. Supplying hot air above the specified temperature into the flow path from around the outer peripheral surface and uniformly mixing the transport airflow and dry snow with the hot air in the flow path Disclosed is a step of forming an atmosphere having a uniform temperature sufficient to melt, and a point whereby each dry snow is transported on a transport airflow, melted and wetted, and blown out from the outflow opening. .

According to such a wet snow making technique, since the snow itself is melted in the flow path, it is possible to solve the first and second problems to some extent as compared with Patent Document 1.
However, heat is exchanged between the airflow, dry snow, and hot air after the airflow, dry snow, and hot air are mixed evenly and then blown out from the outlet opening to make the snow dry. The heat exchange region or heat exchange time until the completion of the aging area (aging space) for heat exchange is not secured.
When the transport speed of the transport airflow is high, dry snow is less likely to adhere to the inner surface of the flow path, but it is difficult to secure a heat exchange time and the dry snow becomes insufficiently moistened. When the transport speed is low, it is possible to secure dry heat by securing sufficient heat exchange time, but dry snow tends to adhere to the inner surface of the flow path. Due to the blockage, it becomes difficult to carry the snow itself.
As described above, it is an important issue to prevent the wet snow from adhering to the inner surface of the duct while ensuring sufficient wet snow.
JP 2000-65690 A JP-A-63-217172

  In view of the above technical problems, the object of the present invention is to efficiently transport each dry snow without adhering to the inner surface of the flow path when transporting the dry snow on the airflow using the flow path. Provided are a wet snow generation method and a wet snow generation apparatus that can flow out from a flow path as wet snow having a desired water content.

In order to achieve the above object, a method for generating wet snow according to the present invention includes:
A step of carrying dry snow toward the outflow opening in a flow path at a predetermined speed or higher in the flow path;
Supplying hot air of a predetermined temperature and a predetermined humidity into the flow channel from around the outer peripheral surface of the flow channel on the upstream side of the outflow opening;
Forming a uniform temperature atmosphere sufficient to melt dry snow in the flow path by uniformly mixing the carrier airflow and dry snow and hot air in the flow path;
In the atmosphere, it has a stage of heat exchange between the conveying airflow and dry snow and hot air up to the outflow opening,
As a result, each dry snow is transported on a transport airflow, melted to become wet snow, and the wet snow is blown out from the outflow opening.

According to the wet snow generation method having the above configuration, when transporting dry snow toward the outflow opening by carrying the airflow at a predetermined speed or higher in the flow path, the outer periphery of the flow path is upstream of the outflow opening. To supply hot air with a predetermined temperature and humidity into the flow path from around the surface, and evenly mix the air flow, dry snow, and hot air in the flow path, and melt the dry snow in the flow path. By forming an atmosphere of sufficient uniform temperature and exchanging heat between the airflow and dry snow and hot air until reaching the outflow opening in the formed atmosphere, the airflow and dry snow and hot air are transferred. As a result of the heat exchange between the two and each other, the atmosphere of a uniform temperature sufficient to melt dry snow is formed in the flow path, so that each dry snow is melted and wetted while flowing wet snow. Blows efficiently from the outflow opening without sticking to the inner surface of the road It is possible.
Here, “snow” has a broad meaning that includes both snowflakes in which snowflakes overlap like natural snow and snow particles like artificial snow made of ice particles. "Has a broad meaning which means not only a snowstorm state due to snowfall but also a situation in which such snowflakes or snow particles move due to wind or passing of a car.

In addition, the wet snow blown out from the outflow opening is placed on the airflow flowing from the back of the outflow opening toward the specimen for the environmental test to be blown into the snow, and then supplied to the specimen, so that The method further includes testing adhesion, and the moisture content of the wet snow may be 1% to 30%.
Furthermore, it is possible to ensure a sufficient heat exchange time for converting the dry snow into wet snow while preventing the dry snow or wet snow from adhering to the inner surface of the pipe line in the transfer stage. In addition, the speed of the carrier airflow should be selected.
Furthermore, it is possible to ensure a heat exchange time sufficient to make dry snow wet in the heat exchange stage while preventing dry snow or wet snow from adhering to the inner surface of the pipeline in the transport stage. As described above, it is preferable to select the length of the pipeline from the mixed region of the carrier airflow and dry snow and hot air to the outflow opening.
In addition, the predetermined speed of the carrier airflow should be 15 meters or more per second.
The predetermined temperature of the hot air is preferably 0 ° C. to 50 ° C.

Furthermore, it is preferable to adjust the moisture content of the wet snow through the adjustment of the atmospheric temperature in the flow path by adjusting the temperature and / or flow rate of the hot air or the temperature and / or flow rate of the carrier airflow.
Furthermore, it is preferable to further include a step of maintaining the temperature of the inner surface of the flow path at zero degree on the downstream side of the portion of the flow path where wet snow is generated.
In addition, the dry snow is preferably artificial snow that breaks ice pieces that have been made into ice particles.

Furthermore, the dry snow may be artificial crystal snow generated using cold air having a predetermined humidity and a predetermined temperature.
As dry snow, natural snow may be used.

In order to achieve the above object, the wet snow generating device of the present invention comprises:
A snowpipe that transports dry snow with a carrier airflow inside and blows out snow from the outflow opening,
A hot air supply pipe communicating with the snow pipe on the upstream side of the outflow opening;
The hot air supply pipe has, at the downstream end thereof, a hot air inflow portion that forms an annular space that covers the entire outer peripheral surface of the snow supply pipe over a predetermined length in the extending direction of the snow supply pipe,
A plurality of hot air inflow openings are equally provided on the outer peripheral surface of the snowpipe covered with the annular space,
Accordingly, an aging space is formed in the snowpipe on the downstream side of the part where the hot air inflow portion of the snowpipe is attached.

Further, in the portion of the snowpipe where the aging space is formed, the snow adhering to the inner surface of the snowpipe is deformed by the microvibration of the snowpipe due to the transport of dry snow or the snowpipe. By adding, it is good to form with the pipe | tube which has a softness | flexibility which is easy to peel from an inner surface.
Further, the aging space of the snowpipe has a double pipe configuration with an outer pipe that covers the snowpipe from outside, and a temperature-controlled airflow is generated in an annular space between the snowpipe and the outer pipe. An air flow supply means is provided to maintain the ice temperature of ice particles in the aging space by flowing cool air in the annular space, and in the aging space by flowing warm air in the annular space. It is better to defrost the clog.
In addition, the portion of the snowpipe that is covered with the annular space may be made of a hard-to-snow-resistant fluororesin.

First, the snow environment test system will be described. As shown in FIG. 1, the snow environment test system 10 uses artificial snow composed of ice particles and simulates a snowstorm by placing the artificial snow on an airflow from behind. Thus, it is configured to spray toward the vehicle V, which is a test specimen, and for that purpose, it has a snowstorm supply system 12 and an airflow supply system 14.
In particular, when continuously blowing toward the vehicle V using the required amount of snowstorm with a predetermined snow quality, where the particle size and moisture content of ice particles are the main influencing factors, the entire height of the vehicle V In order to achieve a desired snowstorm concentration distribution in the height direction of the vehicle V in some cases, a group of ice particles used as artificial snow is manufactured immediately before the test under a predetermined temperature and humidity control. And prompt supply is required.

More specifically, the snow environment test system 10 includes a wind tunnel 16 in which the vehicle V to be tested is disposed, a low temperature chamber 18 disposed above the wind tunnel 16, and an ice making chamber disposed above the low temperature chamber 18. 20, an ice making machine 22 is arranged in the ice making chamber 20, and an ice temperature stabilizing conveyor 24, an ice breaker 26, a blower 28, a cooler 30, and artificial snow distribution are arranged in the low temperature chamber 18. A device 34 is disposed, and a wet snow device 32, an artificial snow blowing nozzle 36, and a snow collecting device 38 are disposed in the wind tunnel 16. In general, ice pieces made in the ice making chamber 20 are cooled at low temperature. Artificial snow is manufactured by crushed ice in the chamber 18 and pulverizing into ice, and the artificial snow is pumped toward the wind tunnel 16 to distribute wet artificial snow into the low temperature air current in the wind tunnel 16. It is configured to be put on snowstorm and sprayed toward vehicle V To have.

The wind tunnel 16 is an open type circulation type, and a measurement chamber 300 in which a vehicle to be measured is installed (open type), and first to fourth bent cylinders 302, 304, 306, 308 (bent portions). Are formed in a substantially rectangular shape in plan view. The air flow generated by the blower 25 passes through the second diffusion cylinder 310, the third bending cylinder 306, the fourth bending cylinder 308, the rectifying cylinder 312 (see FIG. 2), and the contracted flow cylinder 314 (see FIG. 2), and the measurement chamber 300. The air flows into the measurement chamber 300 from the blowout port 316 (see FIG. 2), and flows through the first bending cylinder 302 and the second bending cylinder 304 in this order.
The airflow blown by the blower 25 is measured by once reducing the wind speed (dynamic pressure) of the entire airflow and increasing the pressure (static pressure) in the intermediate body portion, and then passing through the contracted flow drum 314. Therefore, an air flow having a necessary and sufficient air volume (wind speed) can be blown out from the blow-out port 316 to the measurement chamber 300.

As a result, as will be described later, the ice particles that are conveyed by air through the ice making process, the ice breaking process, the separation process, and the wet snow process are blown into the measurement chamber 300 by riding on the airflow from the back toward the vehicle. By adjusting the wind speed of the airflow with the blower 25, the traveling vehicle can be simulated while being a stationary vehicle.
Further, in the case of the circulating wind tunnel 16 for a snowstorm test, a snow repair device 38 is separately provided downstream of the vehicle V in order to separate and collect the snow after the test. In order to separate snow by the inertia effect, an area where the airflow is not rectified is provided downstream of the vehicle V.

The snow blowing supply system 12 is provided in three systems. In each system, a snow supply pipe 40 that connects the ice breaker 26 and the blowing nozzle 36 and an air duct 44 that connects the suction port 42 in the wind tunnel 16 and the ice breaker 26 are provided. In the snow supply pipe 40, an artificial snow distribution device 34 and a wet snow device 32 are connected in this order between the ice breaker 26 and the blowing nozzle 36, while the air duct 44 has an inside of the wind tunnel 16. A blower 28 and a cooler 30 are connected between the suction port 42 and the ice breaker 26.
The artificial snow distribution device 34 is installed on the upstream side of the wet snow device 32. If the artificial snow distribution device 34 is installed on the downstream side, the wet snow is sent to the distribution device 34, and the inside of the distribution device 34 This is to prevent clogging due to adhesion.

The ice making machine 22 is a so-called reamer type ice making machine 22 that produces flaky ice pieces, and a plurality of ice making machines 22 that produce cracked ice pieces according to the total required amount of artificial snow used in the snow environment test. By selecting an arbitrary number from the above and making ice with the selected ice making machine 22 according to the change in the required amount of artificial snow used for the environmental test, the ice making amount is roughly adjusted and the artificial snow used for the environmental test In accordance with the difference between the required amount of artificial snow and the roughly adjusted ice making amount, the evaporating temperature and / or the water temperature and / or the reamer rotation speed are selected in each selected ice making machine 22 in accordance with the difference in the required amount of snow. It has a control device (not shown) that finely adjusts the amount of ice making by adjusting.

The ice crusher 26 mainly includes a rotary feeder (not shown) arranged at the upper part and a pair of crushing drums (not shown) arranged at the lower part, and is supplied by the ice temperature stabilizing conveyor 24. Ice pieces are quantified by a rotary feeder, supplied to a pair of crushing drums, crushed by a pair of crushing drums, and supplied to the snow supply pipe 40 as ice particles having a predetermined particle diameter.

The artificial snow distribution device 34 is used to distribute the artificial snow conveyed by the snow supply pipe 40 to a plurality of branch pipes (not shown). More specifically, the blowing nozzle 36 at the same level is used for the vehicle. The snow supply pipes 40 in each system are branched into a plurality of branch pipes in the width direction of the vehicle V so that a plurality of the snow supply pipes 40 are provided in the width direction of the vehicle V. A blowing nozzle 36 is provided at the tip of the nozzle.

As shown in FIG. 9, the artificial snow distribution device 34 has an upstream end face 105 and a downstream end face 107 parallel to the downstream end face 106 of the snow supply pipe 40 and the upstream end face 104 of each of the plurality of branch pipes 58. The rotating body 110 is disposed, and a rotation driving unit (not shown) that rotates the rotating body 110 at a predetermined rotational speed about the axial direction thereof. The rotating body 110 includes the rotating body 110 as an axis. The pressure-feeding flow path 114 penetrates in the direction, and the pressure-feeding flow path 114 is arranged in a non-contact manner on the upstream end face so as to face and face the outflow opening 116 provided in the downstream end face 106 of the snow supply pipe 40. The intake port 118 is provided with a discharge port 122 disposed in a non-contact manner in close proximity to the inflow opening 120 provided on the upstream end surface of each of the plurality of branch pipes 58 on the downstream end surface. , A plurality of branch pipes 58 each of the inlet openings 120 on the passing track of the discharge port 122 by the rotation of the rotary body 110 is provided to be positioned.
As described above, the snow pumped through the snow supply pipe 40 is distributed to the plurality of branch pipes 58 via the rotating body 110 of the artificial snow distribution device 34.

The wet snow device 32 has a hot air supply pipe 50 that communicates with the branch pipe 58, and the hot air supply pipe 50 is formed at the downstream end of the branch pipe 58 over a predetermined length in the extending direction of the branch pipe 58. A hot air inflow portion 54 that forms an annular space covering the entire outer peripheral surface is provided, and a plurality of hot air inflow openings 56 are evenly provided on the outer peripheral surface of the branch pipe 58 covered with the annular space. An aging space 116 (heat exchange aging region) is formed in the branch pipe 58 on the downstream side of the portion where the hot air inflow portion 54 is attached, and wet snow is formed there.

Regarding the airflow supply system 14, the wind tunnel 16 is formed in a part of the circulation space, and is configured to blow snowstorm over the vehicle height of the vehicle V in one direction from the front to the rear of the vehicle V. Specifically, an air flow having a predetermined wind speed is generated in one direction from the front to the rear of the vehicle V by the blower 25 installed in the circulation space, and the air flow passes through the vehicle V to a predetermined temperature by the cooler 30. It is cooled and returned to the blower 25 to generate airflow again and repeat this.

With regard to the blowing device, the three blowing nozzles 36 for blowing snow 36 are arranged at a predetermined distance in front of the vehicle V at a predetermined distance in the height direction over the vehicle height of the vehicle V. The concentration of the snowstorm to be supplied can be adjusted for each blowing nozzle 36. A snow collecting device 38 is arranged at a predetermined distance behind the vehicle V, and the snowstorm that has passed through the snow collecting device 38 is blower arranged in the low temperature chamber 18 through the suction port 42 in the wind tunnel 16. 28, cooled by the cooler 30, returned to the ice breaker 26, iced by the ice making machine 22, supplied to the ice breaker 26 by the ice temperature stabilization conveyor 24, mixed with the ice particles to be crushed, and again branched. It is used for blowing snow from the blowing nozzle 36 through 58. The blowout nozzle 36 is arranged along the direction of airflow, and the blowout port 102 is installed in the zone of the airflow blown from the blower 25.

In this regard, the blowing snow is caused when the snow blown from each blowing nozzle 36 by the air blown by the blower 28 is blown toward the vehicle V on the air flow blown from the blower 25. As long as snow clogging in the pipe 40 and the branch pipe 58 does not occur, the speed is preferably as low as possible, and the speed of snow blowing is preferably simulated by the airflow blown from the blower 25.
More specifically, when the blizzard is diffused by the diffusion plate 74 (described later) and blown toward the vehicle V, if the pumping speed of the pumped air is high, the speed of the blizzard increases only in the blizzard of the blowing nozzle 36 portion. In addition, while deviating from the natural snowstorm, it is possible to change the speed of the entire diffused snowstorm uniformly by changing the speed of the airflow blown from the blower 25. When simulating the above, it is advantageous to vary the speed of the airflow blown from the blower 25.

A diffusion plate 74 is provided in front of each blowing nozzle 36, and the snowstorm blown out from the blowing nozzle 36 in the low temperature airflow from the blower toward the vehicle V is applied to the diffusion plate 74 as shown in FIG. In this case, the three snow blowing nozzles 36 cooperate with each other so that the snowstorm is distributed over the height of the vehicle V in the front portion of the vehicle V.
In this respect, since the wind tunnel 16 is not a so-called aerodynamic wind tunnel 16 but a simple wind tunnel 16, the distance between the blowing nozzle 36 and the front portion of the vehicle V is about 1 to 3 meters. The snowstorm blown out from the blowout nozzle 36 over a short distance is diffused over the entire height at the front portion of the vehicle V.

As shown in FIG. 2, in each system, the wet snow device 32 is provided on the downstream side of the distribution device 34 in each branch pipe 58, but since each wet snow device 32 has the same structure, One will be described.
In the wet snow device 32, a hot air inflow portion 54 is provided around the branch pipe 58, and the branch pipe 58 extends to the blowing nozzle 36 downstream of the hot air inflow portion 54, and has become wet snow in the hot air inflow portion 54. The ice particles P are pumped by the air flow in the branch pipe 58 and blown out from the blowing nozzle 36.
More specifically, as shown in FIG. 3, the wet snow device 32 has a hot air supply pipe 50 that communicates with the branch pipe 58 on the downstream side of the distribution device 34, and the hot air supply pipe 50 has a downstream end thereof. This section has a hot air inflow portion 54 that forms an annular space 52 that covers the entire outer peripheral surface of the branch pipe 58 over a predetermined length in the extending direction of the branch pipe 58.

The hot air supply pipe 50 may be configured to convey hot air heated to a predetermined temperature by a known heating means (not shown) toward the hot air inflow portion 54 using, for example, a blower. You may supply to the hot air inflow part 54 using the natural attraction | suction by an airflow.
The hot air inflow portion 54 has a cylindrical shape concentric with the branch pipe 58. The hot air supply pipe 50 is connected to the outer peripheral surface 53 of the hot air inflow section 54, and the hot air flowing from the hot air supply pipe 50 into the hot air inflow section 54 has an annular space 52. Through the outer peripheral surface of the branch pipe 58 so as to flow into the branch pipe 58 uniformly.

In the branch pipe 58, the downstream position of the distribution device 34 that forms the hot air inflow portion 54 may be determined as appropriate. The predetermined length L in the extending direction of the branch pipe 58 in the annular space 52 determines the ice particles P according to the temperature and flow rate of hot air flowing through the hot air supply pipe 50 and the temperature and flow rate of the air flow in the branch pipe 58. What is necessary is just to determine suitably so that the atmosphere of uniform temperature sufficient to melt | dissolve may be formed in the branch pipe 58. FIG.
By adjusting the humidity, temperature and / or flow rate of hot air, and the temperature and / or flow rate of the carrier airflow, the moisture content of the wet snow is adjusted through adjustment of the ambient temperature in the branch pipe 58. The moisture content of wet snow is, for example, 1% to 30% in a snow environment test using a vehicle as a specimen.

In this case, while the ice particles P wetted in the branch pipe 58 are pumped by the airflow, they adhere to the inner surface 55 of the branch pipe 58 and cause a change with time in the flow rate of the pumped ice particles P. In order to reliably prevent the ice particles P from being unable to be pumped due to the blockage of the branch pipe 58, or in some cases, the predetermined speed of the transport air flow is preferably 15 meters or more per second. More preferably, it is 20 meters or more per second. The higher the moisture content of the wet snow, the more the adhesion to the inner surface 55 of the branch pipe 58 tends to increase. Therefore, it is necessary to increase the speed of the conveying air flow accordingly.
The temperature of the hot air is preferably 0 ° C. to 50 ° C. If the temperature is 0 ° C. or less, the ice particles P cannot be dissolved. On the other hand, if the temperature exceeds 50 ° C., the ice particles P can be dissolved. However, air has a low heat transfer coefficient, and even if the temperature of hot air is high, heat exchange between the ice particles P or the air flow for pumping is not immediately promoted accordingly, Since the melting may progress abruptly only by the ice particles P, it is set in such a range.

The outer peripheral surface 53 of the branch pipe 58 covered with the annular space 52 is provided with a plurality of hot air inflow openings 56 equally, so that the branch pipe 58 is branched downstream of the portion where the hot air inflow portion 54 is attached. An aging space 116 is formed in the tube 58. Here, the aging space 116 is used to mean an aging region in which each of the ice particles P fed in the branch pipe 58 is gradually and uniformly melted in a uniform temperature atmosphere.
The inflow opening 56 may be provided as a through hole for a cylindrical punching metal material, for example, and the number and the opening area of the inflow openings 56 are uniform over the outer peripheral surface 53 of the branch pipe 58 in the hot air inflow portion 54. As long as an atmosphere having a uniform temperature can be formed in the branch pipe 58 by being provided, it may be determined appropriately.
The portion of the supply pipe 40 covered with the annular space 52 is preferably formed of a hard-to-snow-resistant fluororesin.

The aging space 116 of the branch pipe 58 has a double pipe configuration with an outer pipe (not shown), and an air current that flows a temperature-controlled air current in an annular space (not shown) between the branch pipe 58 and the outer pipe. Supply means (not shown) are provided. Thereby, the ice temperature of the ice particles P in the aging space 116 is maintained by flowing cold air in the annular space, while the clogging in the aging space 116 is defrosted by flowing warm air in the annular space. Is possible.
When the hot air is hot and the flow rate is large and the conveyance airflow speed is slow, the required heat exchange time is short, and the length of the aging space can be shortened accordingly, and the hot air is cold and the flow rate is small and the conveyance airflow speed is high. Therefore, the required heat exchange time is long, and the length of the aging space is lengthened accordingly.

In this respect, while preventing dry snow or wet snow from adhering to the inner surface of the branch pipe 58, in the heat exchange stage, it is possible to ensure a sufficient heat exchange time to make the dry snow wet. The speed of the carrier airflow and / or the length of the aging space from the carrier airflow and dry snow / hot air mixing area to the outlet opening may be selected. For example, the length of the aging space is 3 meters or more.

About the wet snow apparatus 32 which has the above structure, the effect | action is demonstrated below, demonstrating an environmental test method.
First, in each system, ice pieces made by the ice making machine 22 are crushed into ice particles P having a predetermined particle size by the ice breaker 26, and the ice particles P are put on a carrier airflow at a predetermined speed or more by the branch pipe 58. It pumps toward the blowing nozzle 36.
Next, the ice particles P are distributed from the snow supply pipe 40 to the corresponding branch pipe 58 by the distribution device 34, and around the outer peripheral surface 53 at the hot air inflow portion 54 of the branch pipe branch pipe 58 on the upstream side of the outflow opening 102. Hot air having a predetermined temperature and a predetermined humidity is supplied into the branch pipe 58 through the inflow opening 56. In this case, the humidity, temperature and / or flow rate of the hot air and the temperature and / or flow rate of the conveying airflow are adjusted based on the desired water content set for the ice particles P.

More specifically, in the hot air inflow portion 54, the hot air is uniformly provided over the outer peripheral surface 53 of the hot air inflow portion 54 of the branch pipe 58 via the annular space 52 around the branch pipe 58. 56 flows into the branch pipe 58.
Next, in the branch pipe 58 of the hot air inflow portion 54, the carrier airflow, the ice particles P, and the hot air are uniformly mixed to form an atmosphere having a uniform temperature sufficient to melt the ice particles P in the branch pipe 58. As a result, the ice particles P are melted into wet snow while being transported on the transport airflow, and the wet snow is blown out from the outflow opening 102.

In this regard, as shown in FIG. 4 and FIG. 5, the air temperature of the pumped airflow gradually rises in the direction of zero degrees Celsius from the minus range below zero degrees Celsius.
More specifically, in the aging space 116 of the branch pipe 58 on the downstream side of the hot air inflow portion 54, heat exchange is gradually performed between the conveying airflow and the ice particles P and the hot air in an atmosphere of uniform temperature. As a result, the temperature of the conveying air flow rises, and each of the ice particles P starts to melt from the outer surface in contact with the hot air, becomes wet snow, and forms artificial snow that is the ice particles P having a desired water content.

In this case, using the property of air having a low heat transfer coefficient, the ice particles P to be pumped as a whole gradually in the aging space 116 in the atmosphere of the uniform temperature in the branch pipe 58 as a whole. It is possible to melt by heating. For example, only some ice grains P are not melted, or only some ice grains P are not melted rapidly.
Next, the temperature of the inner surface 55 of the branch pipe 58 is maintained at zero degree on the downstream side of the portion of the branch pipe 58 where wet snow is generated, and each of the ice particles P melts further before being blown out from the blowing nozzle 36. So that the water content does not increase.

Next, in each system, wet snow distributed from the blowing nozzle 36 at the tip of each branch pipe 58 is blown out, and is blown as snow blowing toward the vehicle by being sent from the back of the blowing nozzle 36.
In this case, by simulating the wet snow in the natural state, when evaluating the adhesion of the wet snow-like snowstorm to the vehicle, etc., the wet snow is not attached to the inner surface 55 of the branch pipe 58. Appropriate and accurate environmental tests can be conducted.
If the ice temperature of the ice particles P in the aging space increases with the progress of the test, or conversely, the ice particles P freeze, causing clogging in the aging space 116. The ice temperature of the ice particles P in the aging space is maintained by flowing cold air in the annular space between the pipes, while the clogging in the aging space 116 is defrosted by flowing warm air in the annular space. Also good.

According to the wet snow generation method having the above-described configuration, when the dry snow is transported toward the outflow opening 102 in a flow path with a transport airflow at a predetermined speed or higher, the flow path is formed upstream of the outflow opening 102. A hot air having a predetermined temperature and a predetermined humidity is supplied into the flow path from around the outer peripheral surface 110, and the air flow, dry snow, and hot air are uniformly mixed in the flow path, and the dry snow is supplied into the flow path. The air flow and dry snow are formed by heat exchange between the air flow and dry snow and hot air in the formed atmosphere up to the outflow opening. As a result of heat exchange with the hot air, a uniform temperature atmosphere sufficient to melt dry snow is formed in the flow path, so that each dry snow melts and becomes wet, and the wet snow becomes Efficiently without attaching snow to the inner surface of the flow path It can be blown from the exit aperture 102.

As a modified example, as shown in FIG. 6, the portion of the branch pipe 58 in which the aging space 116 is formed may be formed of a flexible tube, and, for example, adhere to the inner surface of the branch pipe 58. If the snow is easily peeled off from the inner surface by bending the twisted pipe 58 due to the slight vibration of the branch pipe 58 due to the transport of dry snow or bending or twisting the branch pipe 58, or if the vinyl hose is wound in a spiral shape An aging space of a desired distance can be provided without taking a place.
Furthermore, as a modified example, as shown in FIG. 7, it is possible to provide a single wet snow device corresponding to a single system instead of providing three systems of the snow blowing supply system 12.

The embodiments of the present invention have been described in detail above, but various modifications or changes can be made by those skilled in the art without departing from the scope of the present invention.
For example, in the present embodiment, the target of wet snow is described as artificial snow formed by crushing ice pieces, but the present invention is not limited thereto, and cold air having a predetermined humidity and a predetermined temperature is used. Artificial crystal snow generated in this way, or natural snow with a low water content may be used.

Further, in the present embodiment, it has been described that the hot air is supplied to the hot air inflow portion 54 through the hot air supply pipe 50 after the ice particles P are started to be pumped by the airflow by the branch pipe 58, but the present invention is not limited thereto. As long as each ice particle P to be pumped is melted in an atmosphere of uniform temperature and can be made into wet snow, hot air may be supplied before the ice particle P is pumped by the air flow, or the ice particle P is pumped And hot air supply may be performed in parallel.
Furthermore, in the present embodiment, the method for adjusting the moisture content of the ice particles P has been described as adjusting the humidity, temperature and / or flow rate of hot air, and the temperature and / or flow rate of the conveying airflow, but is not limited thereto. As long as the desired moisture content of the ice particles P can be adjusted, only the temperature and / or flow rate of the hot air or only the temperature and / or flow rate of the carrier airflow may be adjusted.

1 is an overall schematic diagram of an environmental test system in which a wet snow device according to an embodiment of the present invention is disposed. It is a lineblock diagram showing a wet snow device concerning an embodiment of the present invention. It is a fragmentary sectional view showing the hot air supply part circumference of a wet snow device concerning an embodiment of the present invention. It is a graph which shows the change of the airflow temperature in a snow supply pipe | tube in the wet snow apparatus which concerns on embodiment of this invention. In the wet snow device which concerns on embodiment of this invention, it is the schematic which shows the heat exchange condition between the airflow temperature in a snow supply pipe, hot air, and the ice particle P. FIG. It is a figure similar to FIG. 2 of the wet snow device which concerns on another embodiment of this invention. It is a whole schematic diagram of another environmental test system which arranges a wet snow device concerning an embodiment of the present invention. It is a figure which shows the reproduction state of the wet snow in the conventional snow making apparatus.

V Vehicle P Ice grain D Distance between vehicle and blowing nozzle 10 Snow environment test system 12 Snow blowing supply system 14 Air flow supply system 16 Wind tunnel 18 Low greenhouse 20 Ice making room 22 Ice making machine 24 Ice temperature stabilization conveyor 26 Ice breaker 28 Blower 30 Cooling Device 32 wet snow device 34 distribution device 36 blowing nozzle 38 snow blowing collecting device 40 snow supply pipe 42 suction port 44 air duct 46 rotary feeder 48 crushing drum 50 hot air supply pipe 52 annular space 53 outer peripheral surface 54 hot air inflow portion 55 inner peripheral surface 56 Inflow opening 58 Branch pipe 74 Diffusion plate 102 Outflow opening 104 Upstream end face 105 Upstream end face 106 Downstream end face 107 Downstream end face 110 Rotating body 114 Pumping flow path 116 Outflow opening 118 Intake opening 116 Aging space 300 Measurement chamber 302 First Bent barrel 304 No. Bending cylinder 306 third bending cylinder 308 fourth bending cylinder 310 second dispersion drum 312 rectifying cylinder 314 Chijimiryudo 316 outlet

Claims (15)

A step of carrying dry snow toward the outflow opening by carrying a carrier airflow at a predetermined speed or more in each of the plurality of channels installed in the wind tunnel ;
On the upstream side of the outflow opening, a stage in which hot air having a predetermined temperature and humidity is supplied into the flow path from around the outer peripheral surface of the flow path, and the air flow, dry snow, and hot air are uniformly distributed in the flow path. By mixing, forming a uniform temperature atmosphere sufficient to melt dry snow in the flow path;
In the flow path, by providing an aging space of a predetermined length in the transport direction between the hot air supply unit and the outflow opening, in the atmosphere, the transport airflow and dry snow Heat exchange with hot air, and
As a result, while transporting each dry snow on a transport airflow, it melts and becomes wet snow, and the wet snow is blown out from the outflow opening, and the wet snow blown out from the outflow opening is subjected to environmental tests from behind the outflow opening. It further has a step of performing a test using snowstorm on the specimen by supplying it toward the specimen installed on the downstream side in the blowing direction from the outflow opening while blowing on the airflow flowing toward the specimen, A method for generating wet snow. The method for producing wet snow according to claim 1, wherein the moisture content of the wet snow is 1% to 30% . In the transport stage, while preventing dry snow or wet snow from adhering to the inner surface of the pipeline, in the heat exchange stage, it is possible to ensure a sufficient heat exchange time to make dry snow wet. The method for generating wet snow according to claim 2, wherein the speed of the carrier airflow is selected. In the transport stage, while preventing dry snow or wet snow from adhering to the inner surface of the pipeline, in the heat exchange stage, it is possible to ensure a sufficient heat exchange time to make dry snow wet. The method for generating wet snow according to claim 2, wherein the length of the pipeline from the carrier airflow and the mixed region of dry snow and hot air to the outflow opening is selected. The method for generating wet snow according to claim 3, wherein the predetermined speed of the carrier airflow is 15 meters or more per second. The method for producing wet snow according to claim 3 or 4, wherein the predetermined temperature of the hot air is 0 ° C to 50 ° C. The wet snow according to claim 1, wherein the moisture content of the wet snow is adjusted through adjustment of the atmospheric temperature in the flow path by adjusting the temperature and / or flow rate of the hot air or the temperature and / or flow rate of the carrier airflow. Generation method. The method for generating wet snow according to claim 1, further comprising the step of maintaining the temperature of the inner surface of the flow path at zero degree on the downstream side of the portion of the flow path where wet snow is generated. The dry snow generation method according to claim 2, wherein the dry snow is artificial snow that breaks ice pieces that have been made into ice particles. The wet snow generation method according to claim 2, wherein the dry snow is artificial crystal snow generated using cold air having a predetermined humidity and a predetermined temperature. The wet snow generation method according to claim 2, wherein the dry snow uses natural snow. A plurality of snowpipe pipes , each installed in a wind tunnel, carrying dry snow with a carrier airflow inside, and blowing out snow from the outflow opening ;
A hot air supply pipe that communicates with each snow pipe on the upstream side of the outflow opening, and the hot air supply pipe has a predetermined length in the extending direction of the snow pipe at the downstream end thereof. It has a hot air inflow portion that forms an annular space that covers the entire outer peripheral surface of the snowpipe, and the outer peripheral surface of the snowpipe that is covered by the annular space is provided with a plurality of equal inflow openings for hot air,
Thereby, on the downstream side of the site where the hot air inflow portion of the snowpipe is attached, an aging space of a predetermined length is formed in the transport direction in the snowpipe,
The wet snow blown from the outflow opening is blown into the airflow flowing from the back of the outflow opening toward the environmental test specimen, and supplied to the specimen installed downstream from the outflow opening in the blowing direction. A wet snow generating device characterized by performing a test using a snowstorm on a specimen . The part of the snowpipe where the aging space is formed is such that the snow adhering to the inner surface of the snowpipe is deformed by slight vibration of the snowpipe due to dry snow conveyance or to the snowpipe. The wet snow generating device according to claim 12, wherein the wet snow generating device is formed of a flexible tube that is easily peeled off from the inner surface. The aging space of the snowpipe has a double tube configuration with an outer tube that covers the snowpipe from outside, and an airflow that flows a temperature-controlled airflow in an annular space between the snowpipe and the outer tube Supply means are provided, thereby maintaining the ice temperature of ice particles in the aging space by flowing cold air in the annular space, and clogging in the aging space by flowing hot air in the annular space. The wet snow generating device according to claim 12 or 13, wherein ice is melted. The wet snow generating device according to claim 12 or 13, wherein the portion of the snowpipe covered with the annular space is made of a hard-to-snow-resistant fluororesin.

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