JP4084614B2 - Snow melting structure of roadbed - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a snow melting structure inside a roadbed for melting snow on a residential site, a sidewalk, a roadway, or the like, and more particularly to a submerged heat storage type snow melting structure.
[0002]
[Prior art]
In areas such as Hokkaido where there is snowfall in winter and the outside temperature is negative, so-called road heating equipment is applied to the premises, parking lots, or general roadways and sidewalks to warm the surface of the roadbed. Sometimes it melts snow.
[0003]
Conventionally, in the road heating, as shown in FIG. 3, the heating material 1 is disposed 10 to 20 cm below the surface of the roadbed to warm the roadbed 2. 3 is a base material (heat insulating material) and 4 is a finishing material for a roadbed such as asphalt. As the heating material 1, for example, a heating wire or a hot water pipe is arranged in a pattern.
[0004]
[Problems to be solved by the invention]
However, such a conventional load heating system has a problem that it takes a very long time from when the heating material 1 is activated until snow is actually melted. Even if a heating wire is used as the heating material 1 or circulation heating by a fluid is performed, it is at least 4 to 5 hours until the cold under the roadbed is heated and the heat reaches the roadbed surface and the snow melts. Is necessary.
[0005]
However, during snowfall, quick snow melting is desired for the safety of pedestrians and vehicles. For this reason, in conventional road heating systems, especially in public places, the system power supply is almost always turned on during winter, and snow melting is always possible. Incidentally, in a private place such as a home site, an outside air temperature sensor and a snowfall sensor are arranged, and the drive power is turned on as necessary to melt snow. This is because the melting of snow is delayed, but the economic burden of electricity and gas charges can be reduced.
[0006]
The conventional always-on system drive system that has been adopted on public sidewalks and roadways naturally requires enormous costs. As a result, many municipalities have recently decided to stop or abolish the road heating system itself.
[0007]
In commercial facilities such as private houses, public condominiums, and large-scale retail stores, a roadbed heating type snow melting system is driven based on weather data and detection of snowfall, but the snow melting speed is slow. For this reason, there is often a need to perform forced snow removal, for example, so-called snow shoveling work, use of an underground buried type burner heating device, or switching to snow melting with time in a large snow melting tank.
[0008]
As described above, the conventional continuous system drive method for melting snow on the roadbed has become difficult to maintain and operate the system as the social awareness of the use of taxes increases, and the slowness of snow melting in private houses and commercial facilities is also difficult. This has led to distrust in conventional road heating systems.
[0009]
However, the system principle that the snow melts automatically without the need for human work by heating the roadbed surface itself is based on other snow melting systems such as a forced snow melting device using a burner device or a long time. It has an advantage over a large snowmelt tank that melts snow slowly.
[0010]
Accordingly, an object of the present invention is to enable immediate snow melting and reduce the economic burden on the premise of a system that melts snow by applying heat to the roadbed surface.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the snow melting structure of a roadbed according to the present invention has a heat storage layer provided below the surface of the roadbed, and a heating unit is disposed at a position in contact with the heat storage layer, while the heat and heating unit of the heat storage layer is provided. A plurality of heat storage conductive pipes that conduct generated heat into the lower soil of the heating means are provided, and the heat storage conductive pipe includes an upper end portion and an opening for air release at the lower end or the side surface.
[0012]
Heat storage layer, formed by selectively sand, gravel, volcanic ash, at least one material of the concrete. The heat storage layer has upper and lower design dimensions of 30 cm to 60 cm .
[0013]
[Action]
The snow melting structure of the roadbed according to the present invention stores the heat generated by the heating means in the heat storage layer provided under the surface of the roadbed, and at the same time, guides it into the lower soil of the heating means through the heat storage conduction pipe. Deep geothermal heat (underground temperature) should be raised above a certain level.
[0014]
In this way, even if the heating means is stopped, the temperature of the heat storage layer below the roadbed surface can always be maintained at a preferable temperature (for example, around 20 ° C.). This is because the deep part is heated, so that the temperature drop of the heat storage layer can be minimized even if the outside air temperature falls or snow falls. As a result, even if there is snowfall with the heating means stopped, the snow on the roadbed surface melts immediately.
[0015]
Of course, if the heating means continues to stop for a long time during snowfall, even if a large amount of heat is stored in a deep part, the temperature of the heat storage layer gradually decreases. For this reason, a heating means is driven as needed. The driving condition of the heating means may be controlled on / off by detecting the temperature of the heat storage layer, or may be controlled on / off using a snowfall sensor as in the conventional system. In any case, when the heating means is driven, the temperature of the heat storage layer and the deep underground portion is maintained at a high temperature in a preferable state, and instant snow melting is realized.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing an embodiment of a snow melting structure for a roadbed according to the present invention.
First, the overall structure will be described. 11 is a surface material (finishing material) of a roadbed such as asphalt, and 12 is a base material of the roadbed, for example, a crushed stone layer. Reference numeral 14 denotes a heat storage layer, for example, sand. Reference numeral 21 denotes a heating medium disposed under the heat storage layer 14, and for example, a heating wire or a heating pipe for circulating and flowing the heating medium is laid. It is desirable to arrange the pattern in consideration of thermal efficiency. 16 is a crushed stone layer provided under the heating medium 21, and 18 is natural soil under the crushed stone layer 16. Reference numeral 25 denotes a heat storage conduction pipe, 28 denotes a temperature sensor that measures the temperature of the heat storage layer 14, and 29 denotes a controller (including a boiler device) that controls the heating medium 21 on and off based on the temperature sensor 28.
[0017]
Next, the configuration of each unit will be described. As the surface material 11, it is desirable to use asphalt in a residential site, a parking lot, a promenade, and the like, but in the case of the present invention, the surface material 11 and the base material 12 using crushed stone or the like are not necessarily required. This will be described later.
[0018]
The heat storage layer 14 uses sand in this embodiment. Sand is easy to lay and has a large amount of voids (air layer), so that it can easily store heat, and conducts appropriate heat transfer to the upper roadbed surface (11, 12). The heat storage layer 14 is set to a thickness having a vertical dimension of at least 20 cm or more, preferably 30 to 50 cm, for example.
[0019]
The heat storage layer 14 may store heat and have a certain heat dissipation effect. Therefore, it is not limited to a single layer using sand, and, for example, gravel, volcanic ash, lapped concrete, glass fragments, ceramic fragments, granular rubber, rubber fragments and the like can be appropriately selected and used. You may use not only one type but combining several types according to the environment and construction cost of an application site.
[0020]
In the case of using concrete as the heat storage layer 14, the surface of the roadbed may be a concrete layer. In this case, it is not necessary to provide the surface material 11 or the base material 12 using crushed stone. However, in consideration of construction costs and maintenance at a later date, it is desirable to use the structure of the surface material 11 and the base material 12 that are general roadbed structures.
[0021]
Unlike the heating medium in the conventional load heating system, the heating medium 21 according to the present invention does not attempt to melt snow by directly heating the road surface. The heating medium 21 has a function of continuously maintaining the surface temperature of the roadbed by applying heat directly to the heat storage layer 14 and simultaneously storing heat in the natural soil 18 having a deeper depth. To fulfill.
[0022]
Therefore, the heating medium 21 is not necessarily disposed under the heat storage layer 14. As long as the position is lower than the upper and lower intermediate portions of the heat storage layer 14, the heat storage layer 14 may be disposed in a state of being embedded in the heat storage layer 14. The reason why this exceptional condition is set to a position lower than the upper and lower intermediate portions of the heat storage layer 14 is to allow the heat generated by the heating medium 21 to be supplied to the natural soil 18 having a greater depth. Note that the heating medium 21 may be of any heating type such as an electric type or a fluid circulation type as long as heat can be generated via an appropriate drive control device.
[0023]
In this embodiment, the heating medium 21 is disposed under the heat storage layer 14, and the crushed stone layer 16 that functions as a cushioning material is provided thereunder. Since the crushed stone layer 16 has a large amount of air layer, it also has a heat storage effect.
[0024]
The crushed stone layer 16 should just have the function as a cushion cushioning material for preventing the failure | damage of the heating medium 21 (electric heating wire or a heat pipe) resulting from the load concerning a roadbed surface, or aged deterioration at the minimum. Therefore, not only crushed stone but also sand, volcanic ash, etc. may be used alone or in combination. Furthermore, when the heating medium 21 is installed by being embedded in a flexible heat storage layer material (sand or the like), the crushed stone layer 16 that mainly functions as a cushioning material is not necessarily provided.
[0025]
The heat storage conductive pipe 25 supplies heat to the natural soil 18 in a deep part where construction work cannot be performed. Therefore, the heat storage conductive pipe 25 is provided with an air release opening 27 at least at the lower end. In this embodiment, a plurality of openings 27-2 are also provided on the side surface of the pipe so that heat generated by the heating medium 21 is supplied to the natural soil 18 evenly.
[0026]
It is important to set the depth of the lower end of the heat storage conductive pipe 25. This is because if it is too shallow, the desired effect is impaired, and if it is too deep, the construction cost becomes unnecessarily high. Therefore, the depth of the lower end portion of the heat storage conductive pipe 25 is preferably a depth not exceeding 2 meters from the road surface, more specifically 150 to 170 cm in the case of ordinary road surfaces such as ordinary private houses, condominiums, roadways and sidewalks. Set.
[0027]
The position of the upper end portion of the heat storage conductive pipe 25 is not particularly limited. This is because it is sufficient that the heat generated by the heating medium 21 can be transmitted downward. In this embodiment, the upper end opening is positioned at a position closest to the lower side of the heating medium 21. This is the structure that is the easiest to construct and can reduce equipment costs. However, the same effect can be obtained by placing the upper end of the heat storage conductive pipe 25 in the heat storage layer on the heating medium 21.
[0028]
However, in order to transmit the heat generated by the heating medium 21 evenly to the depth of the natural soil 18 for effective use, it is desirable to locate the upper end opening of the heat storage conductive pipe 25 directly below the heating medium 21. This is because the heat generated in the heating medium 21 is generally directed upward, and a part thereof heats the portion immediately below the lower portion (crushed stone layer 16), but the heat of the crushed stone layer 16 is also lowered upward (naturally). The soil 18) cannot be heated efficiently. However, the roadbed structure of the present invention is intended to keep the temperature of the heat storage layer 14 continuously by giving the natural soil 18 uniform heat uniformly. For this reason, it is advantageous that the heat transmitted in the downward direction among the heat generated in the heating medium 21 is directly sent to the natural soil 18 below through the heat storage conductive pipe 25. In addition, by doing this, it is possible to reliably ensure the stability of the temperature of the heat storage layer 14.
[0029]
After all, the position of the upper end portion of the heat storage conductive pipe 25 depends on the pipe length, the construction cost caused by the pipe length, and some thermal efficiency. Considering these comprehensively, as shown in the present embodiment, it is most desirable to locate the upper end opening of the heat storage conductive pipe 25 immediately below the heating medium 21.
[0030]
The material of the heat storage conductive pipe 25 is not limited, but a light resin material, for example, a vinyl chloride material is used. The inner diameter of the tube is expected to have a plus / minus design margin centered on, for example, 10 cm. Moreover, when using a pipe material with an internal diameter of 10 cm, the distance between adjacent pipes is, for example, about 60 cm. These numbers vary depending on various conditions at the site. When constructing a new facility in a cold region where the outside air temperature is very low, the inner diameter of the heat storage conductive pipe 25 may be over 20 cm, and the arrangement interval (distance between adjacent tubes) is 1 meter. You may set above.
[0031]
The temperature sensor 28 is means for driving the heating medium 21 via the controller 29 when the temperature of the heat storage layer 14 is measured and falls below a preset threshold value. In realizing the present invention, it is desirable that the temperature of the heat storage layer 14 is within an upper and lower range of about 3 ° C. with 20 ° C. in the middle. If it says on the conditions of Hokkaido, if the temperature of the thermal storage layer 14 is kept at 20 degreeC, even if the heating medium 21 has stopped, if it snows, immediate snow melting is possible. Depending on the temperature condition of the heat storage layer 14 maintained at 20 ° C., the roadbed surface (11) is in a condition capable of melting snow while radiating heat, while the snow adhering to it deprives the heat of the roadbed surface (11). Because it melts.
[0032]
The temperature sensor 28 is disposed, for example, in the upper and lower central portion of the heat storage layer 14 or a portion slightly below it. This is because the internal temperature of the heat storage layer 14 does not change so much except for the vicinity of the upper surface. A plurality of temperature sensors 28 may be provided inside the heat storage layer 14. For example, near the upper surface and near the lower surface. This is because the temperature drop condition of the heat storage layer 14 is slightly different depending on the natural environment of the construction site. To make a versatile system, combine the temperature near the upper surface and the temperature slightly below the vertical center, It is desirable to drive and control the heating medium 21 based on accurate numerical measurement.
[0033]
According to such a structure, the temperature of the heat storage layer 14 can be kept at a high temperature of about 17 ° C. to 23 ° C. while being constantly monitored via the temperature sensor 28. For this reason, even if there is snowfall with the heating medium 21 stopped, the surface of the roadbed is maintained at a temperature at which snow can be melted immediately. When the snowfall continues and the temperature of the heat storage layer 14 decreases, the heating medium 21 is maintained. Then, the temperature of the heat storage layer 14 is raised to a preferable range again, and snow melting on the roadbed surface is continued.
[0034]
In the snow melting structure according to the present embodiment, the temperature of the natural soil 18 having a deep depth is maintained high, so that the temperature drop of the heat storage layer 14 does not proceed rapidly. On the other hand, since the direct heating is performed when the heating medium 21 works, the temperature of the heat storage layer 14 recovers to a preferable temperature (around 20 ° C.) in a short time. This is because the temperature to be recovered is 1 to 2 degrees, and even when the heat storage layer 14 is deprived of heat from the surface of the roadbed by snowfall, heat more than the amount of heat lost can be rapidly applied.
[0035]
FIG. 2 illustrates a structure in the case of performing snow melting with a relatively small roadbed area, such as a residential site. A difference from the snow melting structure shown in FIG. 1 is that a heat storage pit 41 made of reinforced concrete is provided in the soil in the site, and the heat stored in the heat storage pit 41 is transferred via the blower fan 43 and the air duct 44 to the heat storage layer 14. It is a point to feed below. In addition, when the construction area is relatively small, a heat insulating material 47 for blocking heat exchange with other general soil outside the site may be provided on the outer periphery in the soil of the construction site as necessary.
[0036]
The heat storage pit 41 is a facility for enabling centralized cooling and heating in the house, and warm or cold air is supplied to the living room in the house via an air supply duct (not shown) connected to the heat storage pit 41. send. Reference numeral 42 denotes a stove that heats the inside of the heat storage pit 41. Reference numeral 46 denotes an exhaust chimney.
[0037]
According to such a structure, the heat stored in the heat storage pit 41 can be sent to the lower side of the heat storage layer 14 via the blower fan 43 and the air duct 44. Therefore, the heat storage layer 14 is preferable in exactly the same manner as in the above embodiment. Temperature conditions can be maintained.
[0038]
In this embodiment, the stove 42, the heat storage pit 41, the blower fan 43, and the air duct 44 function as heating means, and have exactly the same effect as the heating medium (21).
[0039]
The temperature of the heat storage pit 41 is, for example, about 40 ° C. in winter. This heats each room in the house and simultaneously stores heat in the roadbed in the site. In snowy homes, residential heating is an indispensable facility. On the other hand, if it is this structure, the energy required for the heat storage of the roadbed in a site can be performed with little special fuel consumption, utilizing the heating residual heat for a house. The amount of heat absorbed by the soil under the roadbed is much less than the amount of heat that should be given to a residential room with a large heat loss.
[0040]
In addition, when the temperature of the heat storage layer 14 is increased to a preferable temperature by the temperature sensor 28, the power supply to the blower fan 43 may be controlled to be turned off to stop the heat supply to the air duct 44. This is the same as the drive control of the heating medium (21) in the previous embodiment. If the heat insulating material 47 is arranged in the soil in the site, the temperature drop of the heat storage layer 14 can be minimized.
[0041]
On the other hand, according to such a structure, it is possible to cool a residential room in summer using natural soil cold air. As already described, the heat storage conductive pipe 25 is at a position around 170 cm below the surface of the roadbed. At this depth, the soil temperature in summer is always about 5 to 7 ° C. If this cold heat is introduced into the heat storage pit 41 via the heat storage conduction pipe 25 and the air duct 44 by the suction force of the blower fan 43, the cooling in the house in summer can be covered only by the minute driving power of the blower fan 43. I can do it.
[0042]
The heating means according to the present invention may be any one of a heating wire, a fluid circulation pipe, and an air duct, and the arrangement position (depth) thereof is relative to either the heat storage layer (14) or the natural soil (18). However, any place where heat can be supplied may be used. Although the roadbed surface is not preferable, it may be placed in the heat storage layer (14) or below the heat storage layer (14) as long as it is below the vertical center position of the heat storage layer (14). good.
[0043]
【The invention's effect】
As described above, according to the snow melting structure of the roadbed according to the present invention, it is a system that melts snow by applying heat to the surface of the roadbed, and can instantly melt snow and reduce the economic burden.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a snow melting structure according to the present invention.
FIG. 2 is a cross-sectional view showing another embodiment of a snow melting structure according to the present invention.
FIG. 3 is a diagram illustrating a conventional snow melting structure on a road surface.
[Explanation of symbols]
11 Surface material (finishing material)
DESCRIPTION OF SYMBOLS 12 Base material 14 Thermal storage layer 16 Crushed stone layer 18 Natural soil 21 Heating medium 25 Thermal storage conduction pipe 28 Temperature sensor 29 Controller 41 Thermal storage pit 43 Blower fan 44 Air duct 47 Thermal insulation

Claims (1)

A heat storage layer is provided under the surface of the roadbed,
The heat storage layer is formed by selecting at least one material from sand, gravel, volcanic ash, and concrete,
The vertical dimension of the heat storage layer is 30 cm to 60 cm,
While arranging the heating means directly under this heat storage layer,
A plurality of heat storage the conductive pipe to conduct heat to heat and heating means of the heat storage layer is generated under soil pressure heat means provided, heat storage conductive pipe is provided with a opening in the upper end of the lower end or side A snow melting structure for a roadbed comprising an air release opening in at least one of them.

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