JP2003064616A - Snow-melting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a snow-melting system, of which the cost can be cut down while the snow-melting capability of the system is maintained. SOLUTION: The snow-melting system comprises a three-phase AC power source P for supplying power to first to third heat generating bodies R1, R2, R3 via first to third terminals T1, T2, T3, a first switch SSC1 regulating the value of a current flowing through the first heat generating body R1 to a first current value or to a second current value, a second switch SSC2 connected in series to the second heat generating body R2 and regulating the value of a current flowing through the second heat generating body R2 to the first current value or to the second current value, and a third switch SSC3 connected in series to the third heat generating body R3 and regulating the value of a current flowing through the third heat generating body R3 to the first current value or to the second current value. In this system, any one of the first to third switches SSC1 to SSC3 is selected to regulate the value of the current for any one of the first to third heat generating bodies to the first value, while other two switches regulate the values of the currents for other generating bodies to the second value. The switch to be selected is sequentially changed at every a prescribed time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow melting system by a road heating system which removes snow from the surface of a road or the like by utilizing heat generated by a heating element.

[0002]

2. Description of the Related Art In one of the systems for removing snow on pavement surfaces such as roads, passageways in front of buildings, and parking lots, a heating element is buried in the vicinity of the pavement surface in advance, and electric power is supplied to the heating element to heat it. There is a snow melting system that uses a road heating method that melts snow. Such an electric snow melting system is simple and has an advantage over other systems in long-term cost comparison.

However, even in the electric snow-melting system, considering the running cost for a long time, it is desired to further reduce the cost without lowering the snow-melting ability.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and while maintaining snow melting ability,
An object of the present invention is to provide a snow melting system that can further reduce costs.

[0005]

According to the present invention, in order to solve the above problems, first, second and third terminals and a first terminal are provided.
A first heating element connected between the second and third terminals, a second heating element connected between the second and third terminals, and a third
And a third heating element connected between the first terminal and the first terminal;
A three-phase alternating current power supply for supplying electric power to the first to third heating elements via the third terminal, and the first heating element connected in series between the first and second terminals, Is connected in series with the second heating element between the first switch for controlling the current value flowing in the heating element to the first current value or the second current value and the second and third terminals, A second switch for controlling a current value flowing through the second heating element to a first current value or a second current value;
And a third heating element connected in series between the first terminal,
The third switch for controlling the current value flowing through the third heating element to the first current value or the second current value and any one switch of the first to third switches are selected and selected. A switching control unit that controls the first current value by the switch, controls the second current value by the remaining two switches, and switches the selected switch sequentially at a predetermined time interval. A snow melting system is provided in which the first to third heating elements are buried near the surface of a road or the like. Also,
According to the present invention, there is provided a snow melting system in which the first to third switches are semiconductor relays in the above configuration. Further, according to the present invention, there is provided a snow melting system having the above-mentioned configuration, wherein each of the heating elements is composed of a heating wire, and the heating wires are arranged in parallel with each other. Further, according to the present invention, in the above structure, there is provided a snow melting system in which each of the heating elements is composed of a heating wire and the heating wires are arranged in a meandering manner. further,
According to the present invention, in the above configuration, there is provided a snow melting system that has a snowfall detection unit that detects snowfall and that starts operation based on snowfall information from the snowfall detection unit.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below based on examples. 1 and 2 are conceptual views of an embodiment of the snow melting system of the present invention, FIG. 1 is a method of connecting heating elements, and FIG. 2 is an explanatory view of a control unit. In this embodiment, the snow-melting heating element is divided into three, and the current value flowing through each is sequentially changed at fixed time intervals, thereby reducing the power consumption as a whole. The form of the heating element may be a heating wire, a tropical zone or the like, and a heat resistant coated electric wire is preferably used.

In FIG. 1, P is a three-phase AC power source, R1 and R
Reference numerals 2 and R3 denote first, second, and third heating elements (heating lines), respectively, where R1 = R2 = R3 = R ₀ and T1, T2, T
3 are the first, second, and third terminals, respectively, and SSC
1, SSC2 and SSC3 are first, second and third semiconductor relays, respectively. The first heating element R1 is provided between the first terminal T1 and the second terminal T2, and the second heating element R1 is provided.
2 is provided between the second terminal T2 and the third terminal T3, and the third heating element R3 is provided between the third terminal T3 and the first terminal T1. First terminal T1 and second terminal T
Between the two, the first semiconductor switch SSC1 is connected in series with the first heating element R1, and the current value flowing through the first heating element R1 is set to either the first current value or the second current value. Control. A second semiconductor switch SSC2 is connected in series with the second heating element R2 between the second terminal T2 and the third terminal T3, and the current value flowing through the second heating element R2 is the first current value. Alternatively, it is controlled to either the second current value. A third semiconductor switch S is provided between the third terminal T3 and the first terminal T1.
SC3 is connected in series with the third heating element R3 and controls the current value flowing through the third heating element R3 to either the first current value or the second current value. Further, i1 to i3 are current values flowing in R1 to R3, respectively.

In FIG. 2, A, B and C are respectively shown in FIG.
Semiconductor relays SSC1, SSC2, SSC3 of
CONT is a control unit including a semiconductor relay switching unit (not shown), and S is a snowfall detection unit. The snowfall detection unit S is composed of, for example, a snowfall sensor, an outside air temperature sensor, etc., detects the start and end of snowfall, and transmits the information to the control unit CONT. The control unit CONT receives the snowfall start information from the snowfall detection unit S, starts the snowmelt operation, and starts the semiconductor relay SSC.
1, SSC2, SSC3 switching operation,
Upon receiving the snowfall end information from the snowfall detection unit S, the snowmelt operation is controlled to end.

Semiconductor relays SSC1, SSC2, SSC
The timing of switching 3 can be set as shown in FIG. That is, for example, first, SSC1 which is one of the three semiconductor relays is selected, and the semiconductor relay S is selected.
The current value of the first heating element R1 is set to 100 by SC1.
%, And the value of the current flowing through the second and third heating elements R2, R3 by the other semiconductor relays SSC2, SSC3 is 50%. Table 1 shows the current and power flowing through the heating elements R1 to R3 at this time. In addition, in the table, the first
Is 1 and the second current value is 1/2.

[Table 1] This state is sequentially repeated at predetermined time intervals between the first, second, and third semiconductor relays SSC1, SSC2, SSC3.

In the conventional method, three heating elements each have four
If the electric power of 00 is supplied, the total electric power consumption is 1200. However, according to the present embodiment, the power consumption of one heating element is 400 and the remaining two heating elements are 100, respectively, and the total power consumption is 600, which is half the power consumption of the conventional method. .

In the present invention, the electric power applied to one heating element is high so as to raise the roadbed temperature in a short time, and the electric power applied to the remaining two heating elements is the electric power for preventing the temperature drop. To do. The electric power value is calculated for each area by calculating the calorific value from meteorological data (snowfall, outside air temperature, etc.), and is 350 W per unit area (1 m ² )
Combination of 7.5W, 87.5W, 400W, 100
W, 100W combination, 450W, 112.5W,
A combination of 112.5 W and the like can be used. By doing so, it is possible to reduce power consumption without lowering the snow melting capability, and to reduce running costs. The timing of switching the heating element is preferably 20 to 40 minutes, more preferably about 40 minutes.

FIG. 4 shows the relationship between the amount of heat input and the roadbed temperature according to this embodiment. In Figure 4, the power supply is 3 per unit area
The combination of 50 W, 87.5 W, and 87.5 W was used, and the connection was switched every 40 minutes. From the figure, 350
A rapid temperature rise was observed at the point where W was added, and 87.
It can be seen that there is a heat-retaining effect when 5 W is applied. From this, it can be said that sufficient snow melting is possible with an average input power of 175W.

FIG. 5 is a view showing a laid form of three heating elements in this embodiment, and the three heating elements are arranged in a meandering manner so as to be parallel to each other. Such an installation form can raise the roadbed temperature in a short time and prevent the temperature from decreasing. A method of laying three heating elements will be described. For example, a plate-like material made of a heat-fusible resin joined in a grid (hereinafter referred to as a grid-like structure) is used as a base for installing the heating element. Used as. The heat-melting resin used here is the heat of asphalt during construction (140 ° C or higher)
This is to prevent it from melting and affecting the operation of this system after completion. Next, as shown in FIG. 5, the heating wires are placed on the lattice-shaped structure in parallel with each other and meandering, and fixed by using a known fixing tool such as a nylon binding tool. With the heating element fixed to the grid structure, place it on the roadbed and use asphalt for construction. This reduces field work time.

In the above description, the three heating elements have been described as actually three heating lines, but in reality, if they are divided into three groups, the number of heating lines or the number of tropical zones will be more than that. A heating element can be used.

[0015]

As described in detail above, according to the present invention, since the above-mentioned configuration is adopted, a snow melting system can be realized which can further reduce the cost while maintaining the snow melting ability. In addition, according to the present invention, there is an advantage that the heat generation element can be freely varied as long as the heat quantity is equal to or less than the maximum heat quantity by controlling the current by embedding the heat generation element in a maximum design heat quantity. Other snow melting systems cannot change the amount of electricity after construction. Further according to the invention,
There are three heating elements in the basic operation, and it has been proved that snow melting by three heating elements is the most efficient. Moreover, an arbitrary number of combinations of two or more heating elements can be selected according to the required power amount, and the heat generation amount can be freely designed.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an embodiment of a snow melting system of the present invention,
It is explanatory drawing of a connection method.

FIG. 2 is a conceptual diagram of an embodiment of the snow melting system of the present invention,
It is explanatory drawing of a control part.

FIG. 3 is a switching timing chart.

FIG. 4 is a diagram showing a relationship between a heat input amount and a roadbed temperature according to the present embodiment.

FIG. 5 is an explanatory diagram of a laid form of a heating element.

[Explanation of symbols]

P power supply R, S, T power supply terminals SSC1, SSC2, SSC3 Semiconductor relay T1, T2, T3 terminals R1, R2, R3 heating element S Snowfall detector CONT control unit

Claims (5)

[Claims] 1. A first heating element connected between the first, second and third terminals, the first and second terminals, and a first heating element connected between the second and third terminals. Two heating elements and a third heating element connected between the third and first terminals, and three phases for supplying power to the first to third heating elements via the first to third terminals An AC power supply is connected in series with the first heating element between the first and second terminals, and the current value flowing through the first heating element is controlled to the first current value or the second current value. 1 switch and 2nd and 3rd
A second switch that is connected in series with the second heating element between the terminals of the second heating element to control the current value flowing through the second heating element to the first current value or the second current value; A third heating element connected in series between the first terminal and controlling the current value flowing through the third heating element to the first current value or the second current value.
And one of the first to third switches are selected, the selected switch controls the first current value, and the remaining two switches control the second current value, And a switching control unit that performs switching so that the switches to be selected are sequentially changed at predetermined time intervals, and the first to third heating elements are buried near the surface of a road or the like. A snow melting system featuring. 2. The snow melting system according to claim 1, wherein the first to third switches are semiconductor relays. 3. The snow melting system according to claim 1, wherein each of the heating elements is a heating wire, and the heating wires are arranged so as to be parallel to each other. 4. The snow melting system according to claim 1, wherein the heating element comprises heating wires, and the heating wires are arranged in a meandering manner. 5. The snow melting system according to claim 1, further comprising a snowfall detection unit that detects snowfall, and starts operation based on snowfall information from the snowfall detection unit.