JPH0611222A - Method and apparatus for maintaining snow layer - Google Patents

Abstract

PURPOSE:To prevent property change of snow layer in an indoor skiing ground using artificial snow. CONSTITUTION:Correlation of temperature and humidity in a snow layer (S) and the air (Ar) over the snow later (S) is controlled by humidification of the air (Ar) over the snow layer (S) or by controlling the output from a cooling means 3 for cooling the snow layer (S) so that the surface temperature becomes lower than the dew point (td) of the air (Ar) over the snow layer (S), and thereby moisture sublimation from the snow layer (S) to the air can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow layer maintaining method and a snow layer maintaining apparatus used in an indoor artificial snow ski resort or the like.

[0002]

2. Description of the Related Art Regarding the maintenance of a snow layer, the humidity of the air above the snow layer increases due to replenishment of water by personnel's breathing, etc.
As a result, we have previously proposed a device that prevents the property change of the surface of the snow layer due to the increase in the humidity of the air above the snow layer (Japanese Patent Application No. 2-
158426).

[0003]

However, not to mention the outdoor snow layer, but indoor snow layer as well, depending on the atmospheric conditions in the low temperature and low humidity season, the moisture in the snow layer sublimes into the air and this moisture sublimation occurs. Due to the changes in the surface properties of the snow layer, the skiing performance deteriorated for skiing purposes.

In particular, artificial snow made of water-swellable polymer particles that have been hydrated and frozen in a gel state has a high polymer component ratio in the frozen gel due to sublimation of water. The above-mentioned problem was particularly remarkable as compared with the above.

An object of the present invention is to solve the above problem by rational means.

[0006]

The snow layer maintenance method according to the present invention is characterized in that the surface of the snow layer is controlled by humidifying air on the snow layer or by adjusting the output of a cooling means for cooling the snow layer. To adjust the relative temperature-humidity relationship between the snow layer and the air above the snow layer so that the temperature is equal to or lower than the dew point temperature of the air above the snow layer, and prevent sublimation of water from the snow layer into the air. .

Further, the snow layer maintaining device according to the present invention is characterized in that a humidifying means for humidifying air on the snow layer or a cooling means for cooling the snow layer is provided, and the surface temperature of the snow layer and the snow layer are Determining means for determining a height relationship with the dew point temperature of the upper air is provided, and the humidifying means is provided so that the surface temperature of the snow layer is equal to or lower than the dew point temperature of the air above the snow layer based on the determination result of the determining means. Alternatively, a control means for controlling the cooling means is provided.

[0008]

In other words, the sublimation of water in the snow layer is such that the absolute humidity of the air above the snow layer is relatively low relative to the surface temperature of the snow layer, and the dew point temperature of the air above the snow layer is lower than the surface temperature of the snow layer. In other words, in other words, the vapor pressure on the surface of the snow layer is higher than the partial vapor pressure of the air above the snow layer.

Therefore, in each of the above characteristic configurations, the absolute humidity of the air above the snow layer is increased by humidifying the air above the snow layer due to the low humidity of the air above the snow layer due to changes in atmospheric conditions or the like, or By adjusting the output of cooling means to cool the snow layer, the surface temperature of the snow layer is adjusted to the lower side, and the surface temperature of the snow layer becomes relatively lower than the dew point temperature of the air above the snow layer (that is, the steam on the surface of the snow layer). By setting the pressure to be equal to or lower than the water vapor partial pressure of the air above the snow layer), sublimation of water in the snow layer into the air is prevented.

[0010]

[Effects of the Invention] That is, according to the snow layer maintaining method and the snow layer maintaining apparatus of the present invention, it is possible to avoid changes in the properties of the snow layer surface due to moisture sublimation, which could not be dealt with in the past, and to reduce air humidity such as changes in atmospheric conditions. Regardless of the occurrence of the factors, the surface properties of the snow layer can be stably maintained for skiing purposes, such as maintaining high gliding properties.In particular, artificial snow that uses water-swellable polymers causes snow sublimation. By solving the conventional problem that the property of the layer is far from that of natural snow, the adaptability of the polymer artificial snow for skiing purposes can be greatly improved.

Further, according to the present invention, it is possible to prevent the decrease of the snow amount due to the sublimation of water, and it is possible to reduce the labor and cost required for maintaining the snow amount.

[0012]

EXAMPLES Next, examples will be described.

FIG. 1 shows an equipment structure of an indoor artificial snow skiing area, 1 is a building, 2 is a sloping floor provided with heat insulating means, 3 is a cooling pipe laid across almost the entire surface of the sloping floor 2, and 4 is a cooling pipe. It is a low-temperature refrigerator that cools a refrigerant (for example, brine) circulated in the pipe 3.

Numeral 5 is an air conditioning equipment for adjusting the temperature and humidity inside the room, which is provided with a dehumidifying means 5a, a temperature adjusting means 5b, and a humidifying means 5c, and which has return air Ar from the inside and outside air A taken from the outside.
The temperature and humidity of the air mixed with o is adjusted by the air conditioning equipment 5, and this temperature and humidity adjusted air As is sent indoors by the fan 6.

Reference numeral 7 is a detector for detecting the indoor temperature tr and relative humidity r, 8 is a detector for detecting the cooling temperature tp of the cooling pipe 3, and 9 is based on the detection information of these detectors 7, 8. It is a control device that controls the operation of the low temperature refrigerator 4 and the air conditioning equipment 5.

Regarding the formation of the snow layer S, a water-swellable polymer which is impregnated with water and is gelled is spread on the inclined floor 2 to form a water-containing polymer layer, and the interior of the room is kept at a low temperature atmosphere by the air conditioning equipment 5. In this state, the low-temperature refrigerator 4 is operated to cool the hydrous polymer layer through the cooling pipe 3, thereby freezing the hydrous polymer layer, and the frozen polymer layer is referred to as a snow layer S.

The surface layer Sa of the snow layer S in which the water-containing polymer layer is frozen is finely cut and crushed by a cutting device to form a snow surface close to natural.

On the other hand, when used as a ski resort, the control device 9 controls the air conditioner 5 based on the deviation Δtr between the indoor temperature tr detected by the detector 7 and the set value trr so that the indoor temperature tr becomes the set value trr. Temperature control means 5b in
Adjust the temperature control output of.

The set value trr of the indoor temperature tr is
To the extent that it does not cause thermal shock or discomfort to indoor people,
A low temperature value suitable for suppressing melting of the snow layer S is adopted.

In parallel with this indoor temperature adjustment, the control device 9
Is the surface temperature ts of the snow layer S based on the indoor temperature tr detected by the detector 7 and the set value tss of the snow layer surface temperature ts.
Cooling temperature tp of the cooling pipe 3 such that is the set value tss
p is calculated by the following formula,

Tpp = tss + αd (tss-tr) / λ where α is the heat transfer coefficient between air and the snow layer d is the thickness of the snow layer λ is the thermal conductivity of the snow layer

With the calculated cooling temperature tpp as the target cooling temperature, the cooling temperature tp of the cooling pipe 3 is the target cooling temperature t.
The cooling output of the low-temperature refrigerator 4 is adjusted based on the deviation Δtp between the cooling temperature tp detected by the detector 8 and the calculated cooling temperature tpp so that it becomes pp.

The set value tss of the snow layer surface temperature ts can be changed by setting the setting means 9a. Generally, the lower the snow layer surface temperature ts, the higher the dynamic friction coefficient of the snow layer surface. On the other hand, by changing the set value tss of the snow layer surface temperature ts in the above-mentioned cooling temperature adjustment, the skiing property of the ski can be adjusted.

Further, the control device 9 controls the indoor air A based on the indoor temperature tr and the relative humidity r detected by the detector 7.
The dew point temperature td of r is calculated, and the determination unit 9b that determines the height relationship between the dew point temperature td and the set value tss of the snow layer surface temperature ts is provided, and based on the determination result of the determination unit 9b,
The dew point temperature td of the indoor air Ar is higher than the set value tss of the snow layer surface temperature ts by a predetermined temperature Δt (for example, Δt = 1 ° C. de
The dehumidifying means 5a and the humidifying means 5c in the air conditioning equipment 5 are controlled so that the value is adjusted and maintained at a value g) higher.

That is, the set value tss of the snow layer surface temperature ts
A value higher than the above-mentioned predetermined temperature Δt by a target dew point temperature t
dd (= tss + Δt), and in a situation where the dew point temperature td of the indoor air Ar is less than the target dew point temperature tdd when the humidity is not adjusted, the dew point temperature td of the indoor air Ar is set to the target dew point temperature by the indoor humidification by the humidifying means 5c. By increasing the dew point temperature td of the indoor air Ar to a value higher than the surface temperature ts (= tss) of the snow layer S by a predetermined temperature Δt, moisture from the snow layer S to the air is increased. Sublimation is prevented, thereby preventing deterioration of snow quality due to sublimation of water and accompanying deterioration of gliding property.

In addition, indoor air Ar without humidity adjustment
In the situation where the dew point temperature td of A becomes higher than the target dew point temperature tdd, the indoor air A is dehumidified by the dehumidifying means 5a.
The dew point temperature td of r is lowered to the target dew point temperature tdd so that the dew point temperature td of the indoor air Ar becomes equal to the surface temperature t of the snow layer S.
By making the temperature higher than s (= tss) by a predetermined temperature Δt, excessive moisture condensation and frost formation from the air onto the snow layer S are prevented, and as a result, such excessive moisture is prevented. Prevents deterioration of snow quality due to condensation and frost formation, and deterioration of gliding properties.

Even if the humidifying means 5c is operated at the maximum output, the dew point temperature td of the indoor air Ar can be changed to the surface temperature ts of the snow layer S.
In the situation where the temperature cannot be increased to (= tss), the gliding property changes, but the cooling temperature tp of the cooling pipe 3 is lowered by adjusting the output of the low-temperature refrigerator 4 to reduce the snow layer S.
The surface temperature ts of is reduced below the set value tss up to that point, thereby suppressing sublimation of water from the snow layer S.

If the sublimation of water cannot be prevented and the snow layer S becomes dry, water is sprinkled on the snow layer S by an appropriate sprinkling means such as the sprinkler device 10 arranged on the indoor ceiling. By replenishing S with water, the snow quality is restored.

[Other Embodiments] Next, other embodiments will be listed.

When the surface temperature ts of the snow layer S is equal to or lower than the dew point temperature td of the snow layer air Ar, the snow layer S and the snow layer air Ar are placed.
In order to adjust the relative temperature and humidity relationship with
It is also possible to adopt an adjustment mode in which both of humidifying r and increasing the cooling output of the cooling means 3 for cooling the snow layer S to reduce the surface temperature ts of the snow layer S are performed in parallel.

Further, when the humidifying means 5c is not provided, the surface temperature ts of the snow layer S is controlled to be equal to or lower than the dew point temperature td of the air Ar on the snow layer only by adjusting the output of the cooling means 3 for cooling the snow layer S. The adjustment form may be adopted.

In order to grasp the surface temperature ts of the snow layer S, the surface temperature ts of the snow layer S is calculated from the temperature tr of the air Ar above the snow layer and the cooling temperature tp of the snow layer cooling means 3 as in the above-mentioned embodiment. Instead of the calculation form, the surface temperature ts of the snow layer S may be directly measured by a sensor.

By humidifying the air Ar on the snow layer S,
Alternatively, by adjusting the output of the cooling means 3 for cooling the snow layer S,
Surface temperature ts of snow layer S and dew point temperature td of air Ar on the snow layer
The relative temperature / humidity relationship between the snow layer S and the air Ar above the snow layer may be adjusted so that and are equal to each other to prevent moisture sublimation from the snow layer S into the air Ar.

The snow layer S is not limited to an artificial snow layer in which a water-swellable polymer containing water is frozen, and water is sprayed into a sub-freezing atmosphere to freeze and the frozen ice particles are laminated. It may be a snow layer formed in any form, such as a snow layer, or a layer of ice particles formed by cutting ice blocks or ice layers.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the accompanying drawings by the entry.

[Brief description of drawings]

[Fig.1] Facility structure diagram of indoor artificial snow ski resort

[Explanation of symbols]

 3 Cooling Means 5c Humidifying Means 9 Control Means 9b Judging Means Ar Air S Snow Layer td Dew Point Temperature ts Surface Temperature

Claims (2)

[Claims] 1. The surface temperature of the snow layer (S) by humidifying air (Ar) on the snow layer (S) or by adjusting the output of a cooling means (3) for cooling the snow layer (S). The relative temperature and humidity relationship between the snow layer (S) and the air above the snow layer (Ar) is adjusted so that (ts) is equal to or lower than the dew point temperature (td) of the air above the snow layer (Ar), A snow layer maintaining method for preventing sublimation of water from the layer (S) into the air. 2. The snow layer (S) is provided with a humidifying means (5c) for humidifying air (Ar) on the snow layer (S) or a cooling means (3) for cooling the snow layer (S). Surface temperature (ts)
And a determination means (9b) for determining a height relationship between the dew point temperature (td) of the air above the snow layer (Ar) and the determination means (9).
Based on the determination result of b), the humidifying means (5c), or the humidifying means (5c) so that the surface temperature (ts) of the snow layer (S) becomes equal to or lower than the dew point temperature (td) of the air above the snow layer (Ar). A snow layer maintenance device provided with a control means (9) for controlling the cooling means (3).