JPH04329392A - Snow-fall forecasting device and snow melting system utilzing its device - Google Patents

Abstract

PURPOSE:To reduce the running cost for the snow melting operation by carrying out the snow fall forecast with high probability, besides the information of the atmospheric pressure variation in a control sequence and carrying out the efficient preheating on the basis of the snow-fall forecast. CONSTITUTION:A snow-fall forecasting device consists of a road surface termperature sensor 3, outside air temperature sensor 3, atmospheric pressure sensor 4, and a snow-fall forecasting device 6 which receives the output signals of these sensors and forecasts snow fall and outputs the information. Further, a snow melting system is constituted of the snow-fall forecasting device 6, heat source controller 6a which controls a fuel control valve 8 and a pump 13 by the output signals of the snow-fall forecasting device 6, radiator 16 for heat-radiating the warm water heated by a heat exchanger 10 into a road base 1.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a snowfall prediction device that accurately predicts snowfall using information such as changes in atmospheric pressure, and an efficient way to preheat private roads using the snowfall prediction device. This relates to a snow melting system that performs snow melting.

0002

[Prior Art] Conventionally, hot water circulation road heating technology has been developed as a snow melting system for public roads.
Private use is also an extension of that technology. The main purpose of preheating on public roads using this technology is to prevent road surfaces from freezing, but the main purpose of preheating on private roads is to promote snow melting. Commonly used hot water circulation road heating systems include snowfall sensors, outside temperature sensors, road surface temperature sensors,
Information obtained from sensors such as road moisture sensors is used to control the temperature of hot water in the heat source device and the circulation pump in the circulation system.

That is, as shown in the control sequence of FIG.
If it is snowing, the snowfall sensor detects it and outputs a snowfall signal, and the detected temperatures of the outside temperature sensor and road surface temperature sensor at that time are 2 degrees Celsius or less and 10 degrees Celsius or less, respectively (both temperature limits are just examples). ), turn on the heat source device and circulation pump to send hot water underground,
The roadbed is gradually warmed, and when the road surface reaches snow melting temperature, snow melting begins. If the detected temperature does not meet the above conditions, the heat source device and circulation system will not turn on. Also, when it is not snowing, the snow sensor does not output a signal, so the heat source device and circulation system do not turn on. However, when the road surface temperature falls below 2 degrees Celsius (the temperature limit value is just an example), the preheating operation starts. It is done. In this way, the criterion for starting preheating in the control sequence is the road surface temperature, but the road surface temperature mainly depends on the outside air temperature, hot water circulation time, and amount of sunlight.On cloudy days or strong winds, the road surface temperature may be higher than normal. This also reduces system operating time. Then, when it is determined that snow melting is complete based on information such as the end of snowfall, the presence or absence of moisture on the road surface, and the road surface temperature, the snow melting operation described above is stopped.

In such a snow melting system, it usually takes 1 to 1.5 hours from the start of hot water supply to the start of snow melting, according to experience. Therefore, this 1
If snowfall with a high snowfall intensity (amount of snowfall per unit time) occurs during the start-up time of road heating, which takes ~1.5 hours, a considerable amount of snow will accumulate on the road surface. That is, the heat source capacity of road heating is generally 250Kcal/
h・m2, so its snow melting capacity is 2 to 5 cm/h.
becomes. If the snowfall intensity is higher than this, and if the road surface is not preheated, 10 cm of snow may already have fallen by the time the road surface reaches the snow melting temperature. In the past, it was impossible to predict snowfall with each individual snow melting system, so it was desirable to perform preheating operations before snowfall to maintain the road surface at a temperature that would allow snow melting, and therefore preheating operations were often performed.

[0005]

[Problem to be Solved by the Invention] The conventional hot water circulation type road heating described above starts preheating operation to warm the roadbed when the road surface temperature is 2°C or less even when it is not snowing. Therefore, if there is no snowfall for a long time, there is a problem that the operation during that time is wasted and running costs become high. Also, if there is heavy snowfall during the start-up time of road heating,
There is a considerable amount of snow on the road surface, so when heavy snowfall is expected, preheating operation may be carried out before the snowfall as a countermeasure, but if there is no heavy snowfall contrary to expectations, driving during that time is useless. Therefore, there was a problem that running costs were high. Moreover, when predicting snowfall,
When relying on empirical intuition, the accuracy is low, and when based on weather forecasts, the results are about 10 hours in advance, so they are not useful for immediate preheating. However, when heavy snowfall is predicted, if preheating is not performed and there is a large amount of snow of 10 cm or more, the snow melting capacity will be exceeded and the insulation and water absorption properties of snow will be affected. This has the disadvantage that the snow melting performance deteriorates due to characteristics such as snow melting properties, and the snow melting ability of road heating is relatively reduced, making it even more difficult to melt snow, leading to a vicious cycle.

[0006]

[Means for Solving the Problems] In view of the above-mentioned state of the prior art, the present inventor has proposed that in order to efficiently preheat hot water circulation type road heating, preheating based on rational and scientific snowfall forecasting is necessary. We believe that this is important, and have conducted research into highly accurate snowfall predictions. In other words, in order to establish a snowfall prediction method, we investigated and analyzed the correlation between snowfall and temperature and pressure in the snowy areas of Hokkaido and Ura-Japan, and as a result, we found that the Japan Sea Small Cyclone and It was discovered that there is a deep causal relationship between snowfall and snowfall.

[0007] Based on the above-mentioned survey and research results, the present invention incorporates information on pressure changes into the control sequence of the conventional snow melting system, based on the premise that a large amount of snow falls as a low pressure passes. We provide a snowfall prediction device that enables highly accurate snowfall prediction by adding a The configuration includes an air temperature detection means for detecting the outside temperature, a snow covered surface temperature detection means for detecting the snow covered surface temperature, an atmospheric pressure detection means for detecting the atmospheric pressure, and output signals from these detection means are input. It consists of a snowfall prediction means that calculates snowfall, predicts snowfall, and outputs the information.

[0008] The structure of the snow melting system includes an air temperature detection means for detecting the outside temperature, a snow covered surface temperature detection means for detecting the snow covered surface temperature, an atmospheric pressure detection means for detecting the atmospheric pressure, and these detection means. a snowfall prediction device that inputs and calculates an output signal of a snowfall prediction device that predicts snowfall and outputs the information; a snowfall detection device that detects snowfall; the snowfall prediction device and the snowfall detection device; It consists of a heat source device whose operation is controlled by output information from the means, and a radiator which radiates heat generated by the heat source device based on the output information.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a snowfall prediction device according to the present invention and a snow melting system using the snowfall prediction device will be described with reference to the accompanying drawings. Fig. 1 is a system configuration diagram. 1 is an outdoor roadbed, and a road surface temperature sensor 2 is installed in the roadbed 1 as a means for detecting the temperature of the covered snow surface. Also, at appropriate locations outdoors, a road surface temperature sensor 2 is installed as a means for detecting the temperature of the snow-covered surface. An outside air temperature sensor 3, an air pressure sensor 4 as an air pressure detection means, and a snowfall sensor 5 as a snowfall detection means are provided as external sensors, respectively. For the outside air temperature sensor 3, a thermocouple, thermistor, platinum resistor, or the like is used, and for the atmospheric pressure sensor 4, a standard pressure sealed type pressure transducer is used. Furthermore,
A snowfall predictor 6 is provided as a snowfall prediction means for inputting and calculating output signals from the above-mentioned sensors, predicting snowfall, and outputting the information.

[0010] To explain the basic method of snowfall prediction using a specific example, in Fig. 2, (A) shows the temporal change in atmospheric pressure, (B) shows the temporal change in temperature, and (C) shows the snowfall prediction. The prediction procedure is as follows. (1) Find the local maximum and minimum values from the data signal of temporal changes in atmospheric pressure. 1, 2, 3 in the diagram...
...Number 9 corresponds to that. (2) Assuming that snowfall occurs after the time when the atmospheric pressure reaches its minimum value, there are four times in the diagram, 2, 4, 6, and 8, where snowfall is possible. (3) Even if snowfall is predicted, if the temperature is positive and high, it will be rain instead of snow. 6 in the figure corresponds to this. (4) Depending on the region, it may be better to use the threshold value as the absolute value of atmospheric pressure. In other words, this is a case where atmospheric pressure fluctuations during high pressure are not associated with snowfall, and 2 in the figure corresponds to this, and 1015 millibars is used as the threshold value. However, depending on the region, it may snow even at pressures of 1015 millibars or higher, so 2 in the diagram is the time when there is a possibility of snowfall. (5) The end time of the snowfall forecast is the point at which the atmospheric pressure reaches its maximum value.

[0011] A snowfall prediction device configured as described above;
A flowchart of snowfall prediction based on this snowfall prediction method is shown in FIG. That is, the outside air temperature detected by the outside air temperature sensor 3 and the atmospheric pressure detected by the air pressure sensor 4 are input into the snowfall predictor 6, where they are A/D converted at 10 second intervals, and a simple average calculation is performed every 10 samples. , is a representative value of this time (10 seconds x 10 seconds). The representative values sequentially sampled in this manner are temporarily stored in the snowfall predictor 6, and smoothing is performed between the representative values. Time smoothing of the representative values may be performed using a moving average method. Then, successive local maximum values and local minimum values are determined. At this time, the times at which the maximum value and minimum value occur are about 5 minutes later than the current time, but this is not a major problem. Furthermore, it is determined whether the absolute value of the atmospheric pressure is below the atmospheric pressure threshold (1015 mb in this case) set for each region, and if it is below the threshold and the temperature is 3°C or less, the probability of snowfall is determined to be high. A preheating start signal is output to a heat source control device 6a, which will be described later.

Further, a heat source device and a circulation system controlled by the output information from the snowfall predictor 6 are configured as shown in FIG. That is, the heat source device includes the fuel supply pipe 7,
It is composed of a fuel control valve 8, a burner 9, a heat source control device 6a, a heat exchanger 10, etc., and a water inlet pipe 11 connected to the heat exchanger 10 is provided with a hot water temperature sensor 12, a pump 13, and a reserve tank 11a. The outlet pipe 14 from the exchanger 10 is piped to a radiator 16 installed in the roadbed 1,
The return pipe 15 is connected to the inlet pipe 11 to form a circulation system. Further, the fuel control valve 8 and the pump 13 are connected to the heat source control device 6a, and each operates based on the output of a snowfall prediction signal from the snowfall predictor 6 connected to the heat source control device 6a. The hot water heated by the heat exchanger 10 is sent into the roadbed 1 through the outlet pipe 14, passed through the radiator 16, and circulated by the pump 13 through the return pipe 15 and the inlet pipe 11 for preheating. Upon receiving the signal from the predictor 6, the heat source control device 6a causes the fuel control valve 8 and the pump 13 to stop supplying hot water.

FIG. 4 is a control sequence diagram of a snowfall prediction device according to the present invention and a snow melting system using the snowfall prediction device. Since the melting mode is the same as the conventional example shown in FIG. heating-mo
Only de will be explained below. In other words, when it is not snowing, the snowfall sensor does not output a signal, so the heat source device and circulation system do not turn ON, but the snowfall predictor inputs signal outputs from external sensors such as the outside temperature sensor and the atmospheric pressure sensor. , performs arithmetic processing to predict snowfall, and when the atmospheric pressure and outside temperature meet predetermined conditions and the road surface temperature is 2° C. or less, a signal to start preheating is output and the system starts operating. If these conditions are not met, the preheating start signal is not output, and the system returns to its initial state. If, contrary to expectations, there is no snowfall even after three hours have passed since the start of preheating, system operation is stopped to prevent unnecessary preheating. In this way, the snow melting system of the present invention enables efficient preheating. According to experiments, compared to the conventional system that preheats based on the road surface temperature as shown in Figure 5, the snow melting system of the present invention is 1/1
It has been proven that the preheating time is about 0, and the running cost can be significantly reduced as an energy-saving system.

[0014] The temperature, pressure, time, etc. explained in this embodiment are merely examples, and are not limited to these. - Changes may be made as appropriate depending on the location of use and the climatic conditions of the region. Furthermore, although this embodiment describes the case of preheating an outdoor roadbed, the present invention can be applied to preheating and melting snow on gardens, roofs of buildings, etc., regardless of whether they are public roads or private roads. Furthermore, in this embodiment, a hot water circulation type snow melting system was described, but the heat generation method of the heat source device is as follows.
It is not limited to hot water, and may be heating wires, hot air, heat pumps, heat pipes, etc., and the heat source is not limited to combustion energy conversion, but also includes effective use of natural energy and waste heat.

[0015]

Effects of the Invention As described in detail above, the snowfall prediction device according to the present invention and the snow melting system using the snowfall prediction device include an air temperature detection means, a snow covered surface temperature detection means, and an air pressure detection device for detecting atmospheric pressure. and a snowfall prediction device that inputs and calculates output signals from the detection means and outputs snowfall prediction information, a snowfall detection device that detects snowfall, the snowfall prediction device, and It consists of a heat source device whose operation is controlled based on the output information from the snowfall detection means, and a radiator that radiates the amount of heat generated by the heat source device based on the output information. By adding information, it is possible to make highly accurate snowfall predictions, and the snowfall predictions can be used to perform efficient preheating, which can reduce the running costs of snow melting operations, which has great practical value. .

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of an embodiment of a snowfall prediction device according to the present invention and a snow melting system using the snowfall prediction device.

FIG. 2 is an explanatory diagram showing the relationship between atmospheric pressure and snowfall prediction.

FIG. 3 is a snowfall prediction flowchart of the snowfall prediction device according to the present invention.

FIG. 4 is a control sequence diagram of the snowfall prediction device according to the present invention.

FIG. 5 is a control sequence diagram of a conventional snow melting system.

[Explanation of symbols]

1. Roadbed, 2. Road surface temperature sensor, 3. Outside temperature sensor, 4. Air pressure sensor, 5. Snowfall sensor, 6
...Snowfall predictor, 6a.Heat source control device, 7.Fuel supply pipe, 8.Fuel control valve, 9.Burner, 10.Heat exchanger, 11.Water inlet pipe, 11a.Reservation tank. ,
12... Hot water temperature sensor, 13... Pump, 14... Hot water outlet pipe, 15... Return pipe, 16... Heat radiator.

Claims (2)

[Claims] Claim 1: An air temperature detection means for detecting the outside temperature, a snow covered surface temperature detection means for detecting the snow covered surface temperature, an atmospheric pressure detection means for detecting the atmospheric pressure, and output signals from these detection means are inputted. A snowfall prediction device comprises a snowfall prediction means that calculates snowfall, predicts snowfall, and outputs the information. 2. An air temperature detection means for detecting the outside temperature, a snow covered surface temperature detection means for detecting the snow covered surface temperature, an atmospheric pressure detection means for detecting the atmospheric pressure, and output signals from these detection means are inputted. a snowfall prediction device that calculates snowfall, predicts snowfall, and outputs the information;
Comprised of a snowfall detection means for detecting snowfall, a heat source device that controls operation based on output information from the snowfall prediction device and the snowfall detection means, and a radiator that radiates heat generated by the heat source device based on the output information. However, the snow melting system.