Geothermal snow melting system

Abstract

This system provides a low-cost and highly energy-efficient geothermal snow melting system by inducing geothermal heat from buried pipes and blowing it onto roofs to melt snow. [Solution] The underground heat snow melting system 1 of the present invention comprises a downpipe 10 whose upper end is connected to the roof A1 of structure A and whose lower end is connected to an underground pipe B, a first guide means 21 positioned near the underground pipe B of the downpipe 10, and a second guide means 22 positioned above the first guide means 21 of the downpipe 10, wherein the system is configured such that the first guide means 21 heats up to guide the warm air in the underground pipe B into the downpipe 10, and the second guide means 22 heats up to push the warm air in the downpipe 10 upwards so that it can be blown out toward the roof A1 of structure A.

Description

[Technical Field]

[0001] The present invention relates to a geothermal snow melting system, and more particularly to a geothermal snow melting system that induces geothermal heat in buried pipes and blows it onto roofs to melt snow, thereby enabling low-cost and highly energy-efficient use. [Background technology]

[0002] Large steel-frame (S-structure) structures such as logistics warehouses and factories have a large roof area, and especially in cold regions such as Hokkaido and Tohoku, snow accumulation places a large snow load on the roof, making effective snow countermeasures necessary. As a measure against snow accumulation in cold regions, a snow-free structure is becoming widespread, in which the roof of a structure is sloped in a valley shape towards the center, with a drainage channel in the middle. In this snow-free structure, snow on the roof is collected in the center of the structure, gradually melted by the internal temperature of the structure, and the melted snow is discharged through the drainage channel, preventing snow from falling off the roof. Furthermore, in structures designed to allow snow to fall off, technologies have been developed to melt snow accumulated on the roof using snow-melting devices. Patent documents 1 and 2 disclose a snow-melting device for structures designed to allow snow to fall off, in which a heater is attached to the corrugated metal roof and the heat from the heater melts the accumulated snow. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-086530 [Patent Document 2] Japanese Patent Publication No. 2017-186826 [Overview of the project] [Problems that the invention aims to solve]

[0004] Conventional technology has the following problems: <1> Snow-free roofing structures require the installation of a waterproof sheet on the corrugated metal roof to allow snow to remain on the roof throughout the winter. The cost of installing the sheet is approximately 30,000 to 50,000 yen per meter. 2It costs a certain amount, for example, 5000m 2 For steel-framed structures of this size, an additional cost of over 150 million yen is required in addition to the main construction cost. Furthermore, regular maintenance and repair / replacement of waterproofing sheets are necessary, resulting in high maintenance costs. <2> The snow-free structure is 1m 3 Because the structures must withstand snow loads of several hundred kilograms per unit while enduring the winter, they need to be designed with sufficient structural strength to withstand the snow load. This increases construction costs. <3> The snow melting devices described in Patent Documents 1 and 2 have a structure in which heaters are installed over the entire roof, making retrofitting to existing structures difficult and resulting in high installation costs. Furthermore, because they melt snow by heating a large area on the roof, they are energy inefficient and incur high operating costs. <4> The snow melting devices described in Patent Documents 1 and 2 allow melted snow water to flow down to the eaves, and snow-laden wind passes over it and is drawn under the eaves, making it easy for snow cornices and icicles to form at the eaves (Figure 6). When snow cornices or the like form, the melted snow water is blocked at the eaves and repeatedly freezes and thaws, which can damage the sealing material on the roof and induce ice leaks into the building.

[0005] The present invention aims to provide a ground-based snow melting system that solves the above-mentioned problems. [Means for solving the problem]

[0006] The present invention provides a ground-based snow melting system comprising a downpipe with its upper end connected to the roof of a structure and its lower end connected to an underground pipe, a first guiding means positioned near the underground pipe of the downpipe, and a second guiding means positioned above the first guiding means of the downpipe. The system is configured such that heating of the first guiding means guides warm air from inside the underground pipe into the downpipe, and heating of the second guiding means pushes the warm air inside the downpipe upwards so that it can be blown out toward the roof of the structure.

[0007] In the ground-based snow melting system of the present invention, the first and second guiding means may be elongated heating devices that extend in the height direction within the downpipe.

[0008] In the subsurface heat snow melting system of the present invention, the heating temperature of the first induction means may be lower than the heating temperature of the second induction means.

[0009] The underground heat snow melting system of the present invention comprises a downpipe comprising a pipe body and an injection duct connected to the upper end of the pipe body, and the injection duct may comprise a gutter arranged along the eaves of the roof of a structure, a duct cover covering the upper part of the gutter, and a slit opening from between the gutter and the duct cover toward the roof side of the structure.

[0010] The underground heat snow melting system of the present invention comprises a detection means, a first induction means, a second induction means, and a control means electrically connected to the detection means, wherein the detection means detects at least one indicator of outside temperature, outside humidity, outside atmospheric pressure, temperature inside the downpipe, humidity inside the downpipe, atmospheric pressure inside the downpipe, temperature inside the buried pipe, humidity inside the buried pipe, and atmospheric pressure inside the buried pipe, and the control means may control the heating temperature of the first induction means and the second induction means based on the indicator detected by the detection means.

[0011] The underground heat snow melting system of the present invention comprises a detection means and a recording means electrically connected to the detection means, wherein the detection means detects at least one of the following indicators: outside temperature, outside humidity, outside atmospheric pressure, temperature inside the downpipe, humidity inside the downpipe, atmospheric pressure inside the downpipe, temperature inside the buried pipe, humidity inside the buried pipe, and atmospheric pressure inside the buried pipe, and the recording means records the indicator detected by the detection means. [Effects of the Invention]

[0012] The geothermal snow melting system of the present invention has the above configuration and therefore has at least one of the following effects. <1> This system utilizes geothermal heat from buried pipes to melt snow, and since the heating device is used solely as a means of inducing geothermal heat, it is extremely energy-efficient compared to conventional technologies that directly melt snow with heaters. As a result, it has low operating costs and a high CO2 reduction effect. <2> It can be installed simply by attaching it to the eaves of the roof, and does not need to be incorporated into the structural design, resulting in low installation costs. Furthermore, it can be easily retrofitted to existing structures or added to existing ones. <3>Since it is a structure that blows warm air constantly from the eaves towards the roof and collects the melting snow water into the downspout, it can prevent the occurrence of snowdrifts and icicles, and prevent the leakage of sugary substances due to the retention of melting snow water.

Brief Explanation of Drawings

[0013] [Figure 1] Explanation Diagram of the Ground Source Heat Snow Melting System of the Present Invention [Figure 2] Explanation Diagram of the Ground Source Heat Snow Melting System of the Present Invention [Figure 3] Explanation Diagram of Cold Draft [Figure 4] Snow Melting Function (1) of the Ground Source Heat Snow Melting System [Figure 5] Snow Melting Function (2) of the Ground Source Heat Snow Melting System [Figure 6] Explanation Diagram of the Prior Art

Modes for Carrying Out the Invention

[0014] Hereinafter, the present invention will be described in detail with reference to the drawings. In the present invention, "warm air" is used to mean air that is relatively higher in temperature compared to the outside air or the air inside the pipe. Therefore, for example, even if the air is about 5°C, if it is higher in temperature than the outside air, it will be "warm air".

Examples

[0015] <1>Ground Source Heat Snow Melting System (Figs. 1, 2) The ground source heat snow melting system 1 is a system that uses ground source heat to melt the snow accumulated on the roof A1. The ground source heat snow melting system 1 includes at least a downspout 10 extending in the height direction of the structure A, and a guiding means 20 disposed in the downspout 10. In this example, it further includes a detection means 30, a control means 40 electrically connected to the guiding means 20 and the detection means 30, and a recording means 50 electrically connected to the detection means 30. The ground source heat snow melting system 1 can be implemented, for example, with the following configuration. The downspout 10 is arranged along the outer wall of the structure A. The upper part of the downpipe 10 is connected to roof A1, and the lower part is connected to the buried pipe B underground. A control box 40a is placed on the outer wall of structure A. The control box 40a houses the control means 40 and the recording means 50. The control means 40 is electrically connected to an external power supply and communication network. If the detection means 30 itself has a recording function, the detection means 30 may be connected directly to the external network without going through the recording means 50. The outside air sensor 32 of the detection means 30 is placed on the outer wall near the control box 40a and is electrically connected to the control means 40 and the recording means 50. The guide means 20 is placed inside the downpipe 10, and the power cable of the guide means 20 is brought out from the pipe of the downpipe 10 and routed into the control box 40a, where it is electrically connected to the control means 40. The in-pipe sensor 31 of the detection means 30 is placed inside the downpipe 10, a communication cable is pulled out of the downpipe 10 and into the control box 40a, and electrically connected to the control means 40 and the recording means 50. The underground heat snow melting system 1 is characterized by a configuration in which, through the combination of two induction means 20, warm air in the buried pipe B is guided into the downpipe 10, accelerated, and sprayed onto the roof A1.

[0016] <1.1> Structure (Figure 2) The underground heat snow melting system 1 can be installed on structure A, which is a snow-shedding structure. In this example, we will describe a case where structure A is a steel-framed warehouse with a corrugated metal roof. However, structure A is not limited to the above; for example, the structure of structure A may be reinforced concrete (RC) instead of steel. Also, the use of structure A is not limited to a warehouse; it may be a factory, office, etc. Furthermore, the roof of structure A is not limited to a corrugated metal roof; it may be a corrugated slate roof or a standing seam roof.

[0017] <1.2> Buried pipes (Figure 2) The underground heat snow melting system 1 is connected to the buried pipe B which is buried underground. The buried pipe B extends horizontally with a predetermined slope to a depth below the freezing point in the ground adjacent to structure A, and connects to the lower part of the downpipe 10. In this example, we will describe a case where buried pipe B is a reinforced concrete rainwater pipe. However, buried pipe B is not limited to the above; its purpose may be a sewer pipe, etc., and its material may be rigid polyvinyl chloride pipe, etc. Because buried pipe B is less affected by temperature changes at the ground surface, it maintains a constant temperature range (geothermal heat) corresponding to its depth, and the inside of buried pipe B is filled with warm air from the geothermal heat.

[0018] <1.3> Cold draft (Figure 3) Because the warm air inside the buried pipe is less dense and lighter, it tries to enter the downpipe connected to the top. However, in conventional technology that does not have a guide means 20, the cold air from outside is pushed in as a cold draft (moist, high-density cold air) from the top of the downpipe to the bottom of the pipe, preventing the warm air inside the buried pipe from entering the downpipe. Therefore, conventional technology cannot utilize the warmth generated by geothermal energy for snow melting.

[0019] <2> Downpipe (Figure 1) The downpipe 10 is a component that serves both the function of transporting warm air and the function of draining melted snow water. The downpipe 10 extends vertically along the outer wall of structure A and connects roof A1 and buried pipe B. More specifically, the downpipe 10 comprises a pipe body 11, an inlet 12 located at the lower end of the pipe body 11, an outlet 13 located at the upper end of the pipe body 11, a spray duct 14 connecting the outlet 13 and roof A1, and a connecting section 15 provided in the middle of the pipe body 11. The inlet 12 is connected to the top of the buried pipe B underground. The connecting section 15 is the part of the pipe body 11 through which the power cable of the guide means 20 inside the pipe is routed to the outside of the pipe. The connecting section 15 is provided with a plurality of connecting holes 15a that connect the inside and outside of the pipe body 11. In this example, three connecting holes 15a are arranged along the height direction of the pipe body 11.

[0020] <2.1> Injection duct (Figure 1) The injection duct 14 is a component that blows warm air onto the roof A1. The spray duct 14 comprises a long gutter 14a, a long duct cover 14b, and a slit 14c provided between the gutter 14a and the duct cover 14b. In detail, a gutter 14a is placed along the eaves of roof A1, and the outlet 13 of the pipe body 11 is connected to the lower part of the gutter 14a. The upper part of the gutter 14a is covered with a duct cover 14b along its entire length. A gap is created between the side of the eaves gutter 14a on the roof A1 side and the side of the duct cover 14b to form a slit 14c. By installing an injection duct 14 at the top of the downpipe 10, warm air from inside the pipe body 11 can be injected towards the roof A1, efficiently melting the snow on the roof A1. Furthermore, by selecting the height and orientation of the slit 14c, the amount and direction of the warm air injection can be arbitrarily set.

[0021] <3> Guidance means (Figure 1) The induction means 20 is a means for guiding the warm air inside the buried pipe B to the roof A1 by generating heat. The guidance means 20 comprises at least a first guidance means 21 positioned near the buried pipe B inside the pipe body 11, and a second guidance means 22 positioned above the first guidance means 21 inside the pipe body 11. The first induction means 21 and the second induction means 22 can be implemented, for example, as line heaters attached along the longitudinal direction within the pipe body 11. In detail, the line heater of the first guiding means 21 is attached from the connecting section 15 of the pipe body 11 downwards inside the pipe, and reaches the buried pipe B from the inlet 12. The line heater of the second guiding means 22 is attached from the connecting section 15 of the pipe body 11 upwards inside the pipe, and reaches the vicinity of the outlet 13. Since the heating temperature of the line heater can be set by its length, it is easy to design and is particularly suitable as a guiding means 20. The power cables of the first guide means 21 and the second guide means 22 are each routed out of the pipe through the communication hole 15a and into the control box 40a on the outer wall of structure A. However, the induction means 20 is not limited to the above, and for example, it may be a spot type or a winding type instead of a line heater. Further, it may be a hot water type instead of an electric heating type, or may be a structure attached outside the pipe and heating through the pipe wall instead of inside the pipe.

[0022] <3.1>Heating temperature The first induction means 21 and the second induction means 22 can be heated at a predetermined set temperature. The heating temperature of the induction means 20 is set so that the spraying temperature to the roof A1 by the injection duct 14 becomes a positive temperature. The first temperature T 1 only needs to be able to induce relatively high-temperature warm air into the pipe body 11 by ground heat, so the first temperature T for pushing up the cold draft in the pipe body 11 to the discharge port 13 2 can be set to a relatively lower temperature compared to. Therefore, in this example, the first temperature T which is the heating temperature of the first induction means 1 is set lower than the second temperature T which is the heating temperature of the second induction means 2 Specifically, for example, the first temperature T 1 is set to 30 °C, and the second temperature T 2 is set to 35 °C. In the case of this example, by keeping the first temperature T 1 lower than the second temperature T 2 the power consumption of the induction means 20 can be reduced, and the energy efficiency can be further improved.

[0023] <4>Detection means (Figure 1) The detection means 30 is a means for detecting the temperature etc. inside the downspout 10. The detection means 30 includes an in-pipe sensor 31 disposed inside the downspout 10 and an outside-air sensor 32 disposed outside the downspout 10. The in-pipe sensor 31 and the outside-air sensor 32 can be mounted, for example, as a thermistor with waterproof treatment. In addition, for example, a thermocouple, a resistance temperature detector, an optical fiber sensor, etc. may be adopted. The in-pipe sensor 31 detects the air temperature inside the downspout 10 or the air temperature inside the buried pipe B according to its installation location. The outside-air sensor 32 detects the outside air temperature. However, the pipe sensor 31 and the outside air sensor 32 are not limited to temperature sensors; they may also have the functions of humidity sensors or atmospheric pressure sensors. In this case, the pipe sensor 31 and the outside air sensor 32 can detect outside humidity, humidity inside the downpipe 10, humidity inside the buried pipe B, outside atmospheric pressure, atmospheric pressure inside the downpipe 10, atmospheric pressure inside the buried pipe B, etc., depending on their installation location. Alternatively, a small data logger may be incorporated into the detection means 30 so that the detection means 30 itself records the data.

[0024] <5> Control means (Figure 1) The control means 40 is a means for controlling the induction means 20. The control means 40 can be implemented as a combination of a control board equipped with a microcontroller, relays, capacitors, etc., and a control program. The control means 40 is electrically connected to the induction means 20 and the detection means 30. In this example, the control means 40 acquires indicators such as the outside temperature and the temperature inside the downpipe 10 from the detection means 30, and controls the heating temperatures of the first induction means 21 and the second induction means 22 based on these indicators. Details of the control will be described later.

[0025] <6> Recording means (Figure 1) The recording means 50 is a means for recording data related to the underground heat snow melting system 1. The recording means 50 can be implemented as a data logger that collects and stores indicators such as outside temperature. The recording means 50 is electrically connected to the detection means 30 and acquires indicators such as the outside temperature, outside humidity, outside air pressure, temperature inside the downpipe 10, humidity inside the downpipe 10, air pressure inside the downpipe 10, temperature inside the buried pipe B, humidity inside the buried pipe B, and air pressure inside the buried pipe B, which are detected by the detection means 30, at regular time intervals and stores them in internal memory. The stored indicators can be transmitted to remote administrators via a communication network and used for performance evaluation and maintenance of the underground thermal snow melting system 1.

[0026] <7> Snow melting function of geothermal snow melting system The underground heat snow melting system 1 functions as follows: When the first induction means 21 is heated, the temperature near the inlet 12 of the pipe body 11 rises, pushing the cold draft inside the pipe body 11 upwards. This creates an inlet for the warm air inside the buried pipe B at the bottom of the pipe body 11, allowing the warm air inside the buried pipe B to enter the pipe body 11 as an airflow (Figure 4). The warm air that enters the pipe body 11 from the buried pipe B is cooled by the outside air through the pipe wall as it rises inside the pipe, and its rate of ascent gradually decreases. However, the second guiding means 22 installed in the middle of the pipe body 11 heats up, causing the temperature of the warm air to rise again, and it rises inside the pipe at an accelerating rate. The warm air accelerated within the pipe body 11 pushes up the cold draft and is ejected from the outlet 13. This ensures a continuous passage for warm air from the buried pipe B to the outlet 13 within the pipe body 11. The warm air released from the exhaust port 13 fills and pressurizes the injection duct 14, and is then ejected from the slit 14c toward the roof A1 (Figure 5). This heats and melts the snow on the roof A1 from the eaves side, preventing the formation of snow cornices and icicles at the eaves. The melted snow water generated by heating flows into the injection duct 14 along the slope of the roof A1, passes through the pipe body 11, and is discharged into the buried pipe B. In conventional technology, if melted snow water adheres to the inside of the pipe, it may freeze and become blocked by the outside air, but in this invention, warm air is constantly circulating inside the pipe, so there is no risk of freezing.

[0027] <8> Control of heating temperature In this example, the heating temperature of the induction means 20 is controlled by the control means 40. Specifically, it is controlled as follows, for example.

[0028] <8.1> Temperature-based control When the temperature inside the buried pipe B or the pipe body 11 is relatively low, it becomes difficult to push up the cold draft inside the pipe body 11, so it is effective to set the heating temperature of the first induction means 21 relatively high. Also, when the outside temperature is relatively low, the rate at which warm air rises inside the pipe body 11 decreases, so it is effective to set the heating temperature of the second induction means 22 relatively high. Based on the above, the control means 40 can control the first induction means 21 and the second induction means 22 based on the temperature detected by the in-pipe sensor 31, such that the heating temperature increases as the temperature decreases.

[0029] <8.2> Control by atmospheric pressure and humidity When the atmospheric pressure and humidity inside the buried pipe B or the pipe body 11 are relatively high, the rate at which warm air rises will be slower than when the atmospheric pressure and humidity are low. Therefore, it is effective to set the heating temperature of the first induction means 21 to a relatively high level. Based on the above, the control means 40 can control the first induction means 21 and the second induction means 22 based on the atmospheric pressure and humidity detected by the in-pipe sensor 31, so that the heating temperature increases as the atmospheric pressure and humidity increase. [Explanation of symbols]

[0030] 1. Geothermal snow melting system 10 Downpipe 11. Main body of the pipe 12 Inlet 13 Outlet 14. Injection duct 14a Eaves gutter 14b Duct cover 14c slit 15 Communication part 15a Communication hole 20 Guidance means 21 First guidance means 22 Second guiding means 30 Detection means 31 In-pipe sensors 32 Outdoor air sensor 40 Control means 40a Control Box 50 Recording means A structure A1 Roof B Buried pipe T1 1st temperature T2 2nd temperature

Claims

1. A geothermal snow melting system that uses warm air from buried pipes generated by geothermal energy to melt snow on the roofs of structures, A downpipe whose upper end is connected to the roof of the structure and whose lower end is connected to the buried pipe, A first guide means positioned near the buried pipe of the downpipe, The downpipe comprises a second guide means positioned above the first guide means, By heating the first induction means, the warm air inside the buried pipe is guided into the downpipe. The second induction means is configured to be heated in such a way that it can push up the warm air in the downpipe and blow it out toward the roof of the structure. Geothermal snow melting system.

2. The first and second guiding means are characterized by being elongated heating devices that extend in the height direction within the downpipe. The geothermal snow melting system according to claim 1.

3. The heating temperature of the first induction means is lower than the heating temperature of the second induction means. The geothermal snow melting system according to claim 1.

4. The downpipe comprises a pipe body and an injection duct connected to the upper end of the pipe body. The injection duct is characterized by comprising: a gutter arranged along the eaves of the roof of the structure; a duct cover covering the upper part of the gutter; and a slit opening from between the gutter and the duct cover toward the roof side of the structure. The geothermal snow melting system according to claim 1.

5. Detection means and The system comprises the first induction means, the second induction means, and a control means electrically connected to the detection means, The detection means detects at least one of the following indicators: outside temperature, outside humidity, outside atmospheric pressure, temperature inside the downpipe, humidity inside the downpipe, atmospheric pressure inside the downpipe, temperature inside the buried pipe, humidity inside the buried pipe, and atmospheric pressure inside the buried pipe. The control means controls the heating temperatures of the first induction means and the second induction means based on an index detected by the detection means. A geothermal snow melting system according to any one of claims 1 to 4.

6. Detection means and The system comprises a recording means electrically connected to the detection means, The detection means detects at least one of the following indicators: outside temperature, outside humidity, outside atmospheric pressure, temperature inside the downpipe, humidity inside the downpipe, atmospheric pressure inside the downpipe, temperature inside the buried pipe, humidity inside the buried pipe, and atmospheric pressure inside the buried pipe. The recording means is characterized by recording the indicator detected by the detection means. A geothermal snow melting system according to any one of claims 1 to 4.

Images