A loop heat pipe system for controlling the temperature of coal

Abstract

The application provides a loop heat pipe system for controlling coal temperature, which comprises a loop heat pipe and a gas conveying pipe, and the two are fixed as a whole by a rigid sleeve on the outside. The evaporation section of the loop heat pipe is arranged in a coal pile, and the condensing end is arranged in a dry ice storage box. The gas conveying pipe is arranged in parallel with the loop heat pipe, with the loop heat pipe below and the gas conveying pipe above. One end of the gas conveying pipe is connected with the dry ice storage box, and the other end is connected with the coal pile. The application provides a novel loop heat pipe system for controlling coal temperature, which can effectively avoid the spontaneous combustion of the coal pile caused by the heat accumulation and temperature rise, and realizes the resource saving and environmental protection.

Description

Technical Field

[0001] This invention relates to a heat exchanger, and more particularly to a loop heat pipe system for controlling the temperature of coal. Background Technology

[0002] Heat pipe technology, a highly efficient phase change heat transfer element, originated in 1963 and was invented by George Grover at Los Alamos National Laboratory in the United States. It makes full use of the principle of heat conduction and the rapid heat transfer properties of phase change media to quickly transfer the heat of the heated object to the outside of the heat source through the heat pipe. Its thermal conductivity exceeds that of any known metal.

[0003] A loop heat pipe (LHP) is a highly efficient heat exchanger that utilizes the pressure difference generated by the phase change of the working fluid to achieve circulating flow and heat transfer. It typically consists of an evaporator, a condenser, a receiver, and steam and liquid lines. Its working principle is as follows: After a heat load is applied to the evaporator, heat is transferred to the capillary wick via thermal conduction through the evaporator's outer shell. The liquid working fluid evaporates on the outer surface of the evaporator capillary wick, simultaneously forming a new gas-liquid interface and capillary force within the micropores of the capillary wick. The generated vapor, driven by capillary force, flows out from the vapor channel into the vapor line and then into the condenser. After entering the condenser, the vapor absorbs the latent and sensible heat of the superheated vapor through convection heat transfer, thus cooling it into a subcooled liquid. The subcooled liquid enters the liquid main through the liquid line to replenish the evaporator capillary wick, and this cycle continues. The circulation of the working fluid is driven by the capillary pressure generated by the evaporator capillary wick, requiring no external power. Because the condensation and evaporation sections are separate, loop heat pipes are widely used in comprehensive energy applications and waste heat recovery.

[0004] Coal resources play a crucial role. Large-scale coal mining has led to increased demand for coal storage facilities, resulting in spontaneous combustion of mined coal during storage, causing significant waste and harm to coal resources.

[0005] Currently, coal piles in power plants are generally stacked in the form of strip-shaped coal piles. If the stacking time is too long, it is easy to cause oxidation and heat accumulation inside the coal pile. The difficulty in heat dissipation can easily lead to spontaneous combustion or even fire. Existing technologies have proposed many measures to address spontaneous combustion of coal piles, such as using a single heat pipe for heat dissipation. Although this increases heat dissipation to some extent, it cannot effectively suppress the problem of spontaneous combustion of coal piles. Another method is to spray water for cooling. Although it can achieve a significant cooling effect, it requires a lot of manpower, material resources, and financial resources, which not only increases costs but is also very inconvenient to operate.

[0006] In the prior art, CN114623710A discloses a two-stage temperature control device for coal piles based on heat pipes, which comprises: a heat pipe, a thermocouple on the heat pipe, the temperature measuring end of the thermocouple being installed inside the heat pipe, a water spray device installed in the middle of the heat pipe, three water spray pipes evenly arranged on the upper part of the water spray device, and a water pipe installed at the lower part, an electric valve installed on the water pipe, the electric valve being connected to a temperature control switch via a wire, the temperature control switch being connected to the thermocouple via a wire, heat dissipation fins being installed above the heat pipe, and a conical tip being installed at the bottom of the heat pipe. This invention relates to a two-stage temperature control device for coal piles based on heat pipes and a method for preventing spontaneous combustion. This structure solves the problem that a single heat pipe cannot completely suppress spontaneous combustion of coal piles, and that water spraying for cooling increases costs. The water spraying device uses three water spray pipes evenly arranged on the upper part, which greatly improves the cooling speed of the coal pile. At the same time, a temperature control switch is used to set the temperature, and the opening of an electric valve can effectively suppress spontaneous combustion of the coal pile, ensuring the safety of long-term coal storage.

[0007] CN114704985A discloses a two-stage self-regulating device for preventing spontaneous combustion of coal piles. The device comprises an annular sleeve positioned at the oxide layer of the coal pile. The annular sleeve includes an inner tube and an outer tube. Multiple coolant injection ports communicating with the outer tube are arranged circumferentially, and multiple gas injection ports communicating with the inner tube are also arranged circumferentially. A temperature control switch is installed at each coolant injection port and each gas injection port on the outer tube. This invention arranges the entire cooling and temperature reduction system across the entire oxide layer of the coal pile, installing fast-response temperature control switches near each injection port. When the temperature difference between the gas injection port and the spontaneous combustion temperature of the coal pile is within 10-20°C, inert gas is injected through the gas injection ports for flame retardancy. If this fails to achieve a cooling effect, the coolant injection ports on the outer tube are opened to provide efficient cooling with cooling water. Furthermore, when the local temperature of the coal pile rises, the temperature control switches can adaptively open at that location to achieve localized adaptive cooling. This coal pile spontaneous combustion suppression device can effectively suppress spontaneous combustion of coal piles, and it has a simple structure, low cost, and is easy to operate.

[0008] CN116878310A discloses a circulating water-type coal storage pile oxidation heat energy utilization and spontaneous combustion control system, including a chiller unit, a three-way valve, a heat exchange steel pipe, a water pump, a heat exchange device, and an industrial nitrogen generator. One end of the three-way valve is connected to the chiller unit via an inlet pipe, the other end is connected to the industrial nitrogen generator, and the third end is connected to the heat exchange steel pipe via the inlet pipe. The heat exchange steel pipe is buried in the coal pile and contains a safety valve. Its other end is connected to an outlet pipe. The outlet pipe contains a temperature sensor, an on / off gate valve, a water pump, and a heat exchange device, which is connected to the chiller unit at the other end. This invention reduces the coal storage temperature and oxidation rate through circulating water heat exchange, while recovering the energy lost during coal oxidation. When signs of spontaneous combustion are detected, the entire coal pile can be immediately inerted by injecting nitrogen into the windward side, mitigating the risk of spontaneous combustion. This provides technical support for simultaneously solving the problems of calorific value loss and spontaneous combustion caused by coal oxidation.

[0009] CN207556337U discloses a coal pile cooling and temperature measuring device, including a radiator and a temperature measuring device. The radiator includes a sealed double-layered hollow metal tube filled with a heat-conducting medium. Spiral heat-absorbing fins are arranged on the outer side of the heat-absorbing end of the double-layered hollow metal tube, and multiple heat-dissipating fins are arranged on the outer side of the heat-dissipating end of the double-layered hollow metal tube. The temperature measuring device includes a conical metal shell and a thermocouple. The thermocouple is located inside the conical metal shell, which is fixedly installed at the heat-absorbing end of the double-layered hollow metal tube. A wire is threaded through the core of the double-layered hollow metal tube. One end of the wire is connected to the thermocouple, and the other end of the wire extends out of the heat-dissipating end of the double-layered hollow metal tube. An external port is provided at the end of the wire extending out of the heat-dissipating end of the double-layered hollow metal tube. This invention can detect the temperature of a coal pile, prevent spontaneous combustion of the coal pile, and transfer the heat inside the coal pile to the outside air through heat exchange, avoiding spontaneous combustion of the coal pile due to excessive heat accumulation.

[0010] CN219531769U discloses an intelligent anti-spontaneous combustion device for coal piles based on a gravity heat pipe, comprising: a gravity heat pipe inserted into a coal pile; a cooling mechanism connected to the end of the gravity heat pipe away from the coal pile for liquefying volatile gases generated by coal pile oxidation; a gas analysis module including a suction pipe inserted into the coal pile and a gas analyzer connected to the suction pipe; and a comprehensive analyzer whose signal input terminal is connected to the gas analyzer and whose signal output terminal is connected to the cooling mechanism. Specifically, the gas reflecting the spontaneous combustion trend is transmitted to the gas analyzer through the suction pipe, and the integrated gas data is sent to the comprehensive analyzer and a signal is sent to the cooling mechanism, thereby liquefying and cooling the volatile gases generated by coal pile oxidation in the gravity heat pipe. This allows for precise quantitative measurement of the concentration of multiple gases, thus accurately determining the spontaneous combustion trend of the coal pile and preventing resource waste from the anti-spontaneous combustion device.

[0011] In the aforementioned prior art, the heat pipe device for controlling coal temperature is relatively complex and has a limited function. The heat pipe device for controlling coal temperature in this invention combines the high-efficiency thermal conductivity of the heat pipe with the phase change inertization properties of dry ice, designing a heat pipe system for pre-treatment and temperature control of coal during its self-heating and spontaneous combustion stages. This effectively prevents spontaneous combustion of coal piles due to heat accumulation, achieving resource conservation and environmental protection. Summary of the Invention

[0012] To overcome the defects and shortcomings of existing technologies, this invention provides a novel loop heat pipe heat exchange structure. The technical solution of this invention is as follows: A loop heat pipe system for controlling coal temperature includes a loop heat pipe and a gas delivery pipe, both fixed together as a single unit by a rigid sleeve. The two pipes are respectively placed in corresponding slots within the rigid sleeve. The evaporation section of the loop heat pipe is located in the coal pile, and the condensation section is located in a dry ice storage box. The gas delivery pipe is arranged parallel to the heat pipe, with the heat pipe below and the gas delivery pipe above. One end of the gas delivery pipe is connected to the dry ice storage box, and the other end is connected to the coal pile.

[0013] As an improvement, the heat pipe evaporation section is arranged at fixed points in the coal pile, and the outer side is equipped with ring fins to enhance heat transfer.

[0014] As an improvement, the rigid sleeve is arranged in sections with quick couplings. The sections are connected by quick couplings, which facilitates transportation and assembly, and at the same time allows for flexible control of the working length of the heat pipe and gas transmission pipe.

[0015] As an improvement, the condenser section is designed in a "bow" shape.

[0016] As an improvement, when a rapid rise in the temperature of the coal pile at the monitoring point is detected, reaching a low-risk warning level, the working side of the heat pipe is activated. The heat pipe then dissipates the heat in a timely manner, preventing further heat accumulation. When a high-risk alarm is triggered due to spontaneous combustion of the coal pile at the monitoring point, the temperature control switch and vacuum pump are turned on, causing the gas pipeline to operate. Heat is released through the condensation section of the heat pipe, causing dry ice to sublimate. The generated CO2 is then transported to a high-temperature location through the gas pipeline. The heat absorption of dry ice sublimation and the inertization of O2 by CO2 diffusion prevent spontaneous combustion in that area from developing further.

[0017] As an improvement, the gas pipeline is equipped with multiple branch pipes in the coal pile, and each branch pipe is equipped with a control valve to control the CO2 output of the branch pipe.

[0018] As an improvement, when spontaneous combustion is detected at a certain location in the coal pile at the monitoring point, the control valve of the branch pipe closest to that location is opened, thereby quickly outputting CO2.

[0019] As an improvement, the CO2 output is greatest at the spontaneous combustion location, and the amount of CO2 output from the branch pipe decreases as the distance from the spontaneous combustion location increases.

[0020] As an improvement, the CO2 output is controlled by adjusting the valve opening.

[0021] As an improvement, spontaneous combustion can be determined by detecting the gases produced during combustion or by detecting the temperature.

[0022] As an improvement, the dry ice storage chamber and gas pipeline are covered with heat-insulating material.

[0023] As an improvement, the rigid sleeve is arranged in sections with quick couplings. The sections are connected by quick couplings, which facilitates transportation and assembly, and at the same time allows for flexible control of the working length of the heat pipe and gas transmission pipe.

[0024] Compared with the prior art, the present invention has the following advantages: 1. By coupling heat pipe conduction and dry ice phase change inerting, and controlling the connection between the heat pipe condenser section and the dry ice storage device, different methods can be used to handle different stages of coal spontaneous combustion. During the coal self-heating period, heat is simply dissipated by opening the heat pipe to prevent heat accumulation and spontaneous combustion. When signs of spontaneous combustion appear, the temperature control switch is turned on, and the heat released from the heat pipe condenser section causes the dry ice to sublimate. Through heat pipe conduction, dry ice sublimation heat absorption, and CO2 diffusion, triple inerting is achieved, which not only cools the coal but also isolates it from oxygen. At the same time, the heat released from the heat pipe is reused, improving energy utilization.

[0025] 2. The dry ice storage chamber and the heat pipe condensing section are connected by a three-layer structure consisting of a double-layer temperature-controlled switch partition with heating elements sandwiched inside. The switch opening is controlled based on the detected temperature, thereby controlling the contact between the condensing section and the dry ice storage chamber. This allows for adjustment under different operating conditions. When dry ice inerting is not required, the heat transferred from the cold end of the heat pipe is isolated. In the early stages, the heat pipe can be used alone to cool the hot spots, avoiding excessive use of dry ice, saving resources and reducing costs. At the same time, the internal heating elements can effectively prevent untimely handling due to heat pipe failure. Even in the event of heat pipe failure, the heating elements can still provide heat to the dry ice storage chamber without affecting the inerting process of the hot spots. Attached Figure Description

[0026] Figure 1 This is a two-dimensional structural diagram of the loop heat pipe system for controlling coal temperature according to the present invention; Figure 2 This is a three-dimensional structural diagram of the loop heat pipe system for controlling coal temperature according to the present invention; Figure 3 This is a front view of the three-dimensional structure of the loop heat pipe system for controlling coal temperature according to the present invention; Figure 4 This is a left view of the arrangement of the gas transmission pipe and the loop heat pipe in the casing of the present invention; Figure 5This is a three-dimensional schematic diagram showing the arrangement of the main pipe, branch pipes and control valve of the dry ice gas transmission pipe inside the casing of the present invention in the coal storage pile. Figure 6 This is a three-dimensional schematic diagram of the dry ice storage box of the present invention, along with the gas inlet and the location of the vacuum pump; Figure 7 This is a simplified diagram of the loop heat pipe in this invention; Figure 8 This is a three-dimensional schematic diagram of the gas delivery pipe and loop heat pipe of the present invention arranged in parallel inside the dry ice storage box.

[0027] 1. Loop heat pipe; 11. Core evaporator; 12. Steam piping; 13. Liquid piping; 14. "Bow" shaped condenser section; 15. Outer ring ribs of the evaporator section; 2. Dry ice storage box; 3. Temperature control switch; 4. Electric heating element; 5. Dry ice gas delivery pipe; 51. Dry ice gas delivery pipe inlet; 6. Dry ice gas delivery branch pipe; 7. Control valve; 8. Three-way valve; 9. Vacuum pump; 10. Rigid sleeve; 101. Quick coupling. Detailed Implementation

[0028] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] Figure 1 A loop heat pipe system for controlling coal temperature is demonstrated. The system includes a loop heat pipe 1 and a gas delivery pipe 5. Preferably, the two are fixed together as a whole by a rigid sleeve 10, with each pipe placed in a corresponding slot within the rigid sleeve 10. The evaporation section of the loop heat pipe is located in the coal pile, and the condensation section is located in a dry ice storage box. The gas delivery pipe is arranged parallel to the heat pipe, with the heat pipe below and the gas delivery pipe above. One end of the gas delivery pipe is connected to the dry ice storage box 2, and the other end is connected to the coal pile.

[0030] By coupling heat pipe conduction and dry ice phase change inerting, a temperature control switch between the heat pipe condenser and the dry ice storage device is activated only when the temperature reaches a threshold, allowing for different treatment methods at different stages of coal spontaneous combustion. During the coal self-heating period, the heat pipe is activated to promptly dissipate heat and prevent heat accumulation that could lead to spontaneous combustion. When signs of spontaneous combustion appear, the temperature control switch activates, utilizing the heat released from the heat pipe condenser to sublimate the dry ice. This triple inerting process—heat pipe conduction, dry ice sublimation heat absorption, and CO2 diffusion—serves as both cooling and oxygen isolation, while simultaneously reusing the heat released from the heat pipe to improve energy efficiency.

[0031] As an improvement, a vacuum pump was installed in the gas pipeline to deliver CO2 gas to the coal pile.

[0032] As an improvement, a circulation pump is installed in the heat pipe to circulate the fluid inside the heat pipe.

[0033] As an improvement, the dry ice storage chamber is equipped with an electric heating element 4 for auxiliary heating. The internal heating element can effectively prevent untimely processing due to heat pipe failure or other reasons. Even in the event of heat pipe failure, the heating element can still be turned on by the temperature control switch 3 to heat the dry ice storage chamber without affecting the inerting treatment of hot spots.

[0034] As an improvement, the heat pipe evaporation section is arranged at fixed points in the coal pile, and the outer side is equipped with ring ribs 15 to enhance heat transfer.

[0035] As an improvement, the condenser section 14 is designed in a "bow" shape.

[0036] As an improvement, the rigid sleeve 10 is arranged in sections with quick couplings, which are connected in sections by quick couplings 11, making it easy to transport and assemble, while also allowing for flexible control of the working section length of the heat pipe and gas transmission pipe.

[0037] As an improvement, when a rapid rise in the temperature of the coal pile at the monitoring point is detected, reaching a low-risk warning level, the working side of the heat pipe is activated, for example, by turning on the circulation pump. The heat pipe will then dissipate the heat in a timely manner, preventing further heat accumulation. When a high-risk alarm is triggered due to spontaneous combustion of the coal pile at the monitoring point, the vacuum pump is activated, and if necessary, the temperature control switch is turned on to activate the gas pipeline side. Heat is released through the condensation section of the heat pipe to promote the sublimation of dry ice. The generated CO2 is then transported to a high-temperature location through the gas pipeline. The heat absorption of dry ice sublimation and the inertization of CO2 by isolating O2 are utilized to prevent spontaneous combustion in that area from developing further.

[0038] As an improvement, the gas transmission pipe 5 is equipped with multiple branch pipes 6 within the coal pile, each with a control valve 7. The CO2 output of the branch pipe is controlled by these control valves. By controlling the branch pipe valves, the CO2 output and its magnitude at each location can be controlled, allowing for targeted control and CO2 conservation.

[0039] As an improvement, when spontaneous combustion is detected at a specific location on the coal pile at the monitoring point, the control valve of the branch pipe closest to that location is opened, thereby rapidly outputting CO2. By selectively outputting CO2, spontaneous combustion can be extinguished in a timely manner, further conserving CO2.

[0040] As an improvement, the CO2 output is highest at the spontaneous combustion location, and decreases with distance from the spontaneous combustion location. This configuration allows for the rapid extinguishing of spontaneous combustion points with a small amount of CO2, while also ensuring the area around the combustion point is enveloped in CO2 to prevent reignition and consolidate the extinguishing effect. Achieving good technical results with a small amount of CO2 further reduces costs.

[0041] As an improvement, the CO2 output is controlled by adjusting the opening degree of valve 7.

[0042] As an improvement, spontaneous combustion can be determined by detecting the gases produced during combustion or by detecting the temperature.

[0043] As an improvement, the dry ice storage chamber and gas pipeline are covered with heat-insulating material.

[0044] As an improvement, the gas delivery pipe is positioned parallel to the heat pipe, above it. The dry ice storage chamber has an opening in its side wall, connected to the gas delivery pipe via a converging pipe (large side wall opening, small gas delivery pipe diameter) to prevent CO2 gas from blocking the inlet. A vacuum pump is also installed at the inlet to quickly draw CO2 gas into the delivery pipe. This arrangement is primarily because the condenser releases heat, causing the dry ice near the condenser to evaporate first. Therefore, by placing the gas delivery pipe and the condenser together, and because gas flows upwards, positioning it above the condenser section allows for rapid entry of CO2 gas, which is then promptly delivered to the coal pile.

[0045] As an improvement, the flow area at the inlet of the gas delivery pipe decreases along the flow direction of the fluid in the condensation section, and a vacuum pump is installed at the inlet for evacuation. The main reason is that along the flow direction of the fluid in the condensation section, the fluid temperature decreases, the heat exchange decreases, and therefore the amount of CO2 produced decreases. Therefore, by adjusting the flow area distribution at the inlet, the problem of gas blockage can be avoided, maximizing the amount of CO2 output to the coal pile.

[0046] As an improvement, see Figure 6 and Figure 8 The gas delivery pipe is installed parallel to the condenser section of the heat pipe inside the dry ice storage box, positioned above the condenser section, and fixed together with a fixing device. Multiple gas inlets are provided on the gas delivery pipe to facilitate the entry of CO2 gas. This arrangement is primarily because the condenser section releases heat, causing the dry ice near it to evaporate first. Therefore, by placing the gas delivery pipe and the condenser section together, and because gas flows upwards, its placement above the condenser section allows for rapid entry of CO2 gas, which is then promptly delivered to the coal pile.

[0047] As an improvement, the flow area of ​​the air inlet decreases along the flow direction of the fluid in the condensation section. The main reason is that along the flow direction of the fluid in the condensation section, the fluid temperature decreases, the heat exchange decreases, and therefore the amount of CO2 produced decreases. Therefore, by distributing the flow area of ​​the air inlet, localized gas blockage and insufficient gas supply can be avoided, thus preventing overall air inlet blockage and maximizing the amount of CO2 output to the coal pile.

[0048] As an improvement, the flow area of ​​the air inlet becomes progressively smaller along the flow direction of the fluid within the condensation section. This improvement further prevents air inlet blockage and maximizes the output CO2 volume.

[0049] As an improvement, a coal self-combustion pretreatment system based on heat pipe heat conduction and dry ice phase change inerting is proposed. The system includes: a single large pipe organically combining a loop heat pipe and a gas transmission pipe. The loop heat pipe and gas transmission pipe are placed parallel to each other, with the heat pipe below and the gas transmission pipe above, respectively placed in corresponding slots within a rigid sleeve. The pipe is segmented with quick-connect couplings for segmental connection. The heat pipe evaporation section is centrally located within the coal pile, with ring ribs on the outside to enhance heat transfer. The condensation section is designed in an "arch" shape. The dry ice storage chamber connects to the gas transmission pipe. Both the gas transmission pipe and the dry ice storage chamber are covered with insulation material, and the gas transmission pipe outlet is on the same side as the heat pipe evaporation section. When a rapid increase in the temperature of the coal pile at the monitoring point is detected, only the circulation pump is turned on to make the heat pipe work. The heat pipe works to dissipate heat in time and avoid heat accumulation. When spontaneous combustion is detected in the coal pile at the monitoring point, the corresponding branch pipe control valve is opened, and the temperature control switch is turned on to make one side of the gas pipeline work. Heat is released through the condensation section of the heat pipe to cause dry ice to sublimate. The generated CO2 is transported to the high-temperature position through the gas pipeline. The heat absorption of dry ice sublimation and the inertization of O2 by CO2 diffusion are used to prevent spontaneous combustion in this area from developing further.

[0050] The present invention has the following advantages: 1. By coupling heat pipe heat conduction and dry ice phase change inertization, and by controlling the switch connecting the heat pipe condensation section to the dry ice storage device, different methods can be used to treat different stages of coal spontaneous combustion.

[0051] 2. During the self-heating period of coal, heat should be dissipated in a timely manner by turning on the heat pipes to avoid heat accumulation that could lead to spontaneous combustion.

[0052] 3. The dry ice storage chamber and the heat pipe condensation section are connected by a temperature-controlled switch heating element structure. By controlling the opening of the temperature control switch, adjustments can be made under different operating conditions. Specifically, during the coal self-heating period, the heat pipe can be used alone to cool the hot spots, avoiding excessive use of dry ice, saving resources and reducing costs. At the same time, the internal heating element can effectively prevent untimely handling due to heat pipe failure. Even if the heat pipe fails, the heating element can still be used to heat the dry ice storage chamber without affecting the inerting treatment of the hot spots.

[0053] 4. When coal shows signs of spontaneous combustion, the heat released from the condenser section of the heat pipe is used to sublimate dry ice. Through heat conduction of the heat pipe, heat absorption by dry ice sublimation, and CO2 diffusion, triple inerting is achieved, which has the functions of cooling and isolating oxygen. At the same time, the heat released by the heat pipe is reused, improving energy utilization.

[0054] 5. A ring rib structure is installed on the outside of the heat pipe evaporator section to improve heat transfer capacity and better collect and dissipate heat from the high-temperature zone of the coal pile.

[0055] 6. The dry ice storage chamber and gas pipeline are covered with heat insulation material to reduce the loss of dry ice sublimation and ensure that the CO2 generated by dry ice sublimation can diffuse to the high-temperature zone of the coal pile at a lower temperature, while preventing the low temperature from affecting the normal operation of the heat pipe.

[0056] 7. The heat pipe condenser section is designed in an "arch" shape for easy installation and to make the dry ice heat more evenly.

[0057] 8. The rigid sleeve is arranged in sections with quick couplings. The sections are connected by quick couplings, which facilitates transportation and assembly, and at the same time allows for flexible control of the working length of the heat pipe and gas transmission pipe.

[0058] While the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A loop heat pipe system for controlling coal temperature, the system comprising a loop heat pipe and a gas supply pipe, wherein the evaporation section of the loop heat pipe is disposed in a coal pile, and the condensation section is disposed in a dry ice storage box, the gas supply pipe is disposed parallel to the heat pipe, with the heat pipe below and the gas supply pipe above, one end of the gas supply pipe being connected to the dry ice storage box and the other end being connected to the coal pile; when a rapid increase in the coal pile temperature at the monitoring point is detected to reach a low-risk warning level, the working side of the heat pipe is activated, and the heat pipe operates to promptly dissipate heat and prevent further heat accumulation; when spontaneous combustion is detected in the coal pile at the monitoring point and a high-risk alarm is triggered, the temperature control switch and vacuum switch are activated. A pump operates on one side of the gas delivery pipe, releasing heat through the condenser section of the heat pipe to cause dry ice to sublimate. The generated CO2 is then transported to a high-temperature location via the gas delivery pipe. The sublimation of dry ice absorbs heat, and the diffusion of CO2 isolates O2 for inertization, preventing spontaneous combustion at that high-temperature location from progressing further. The gas delivery pipe is installed parallel to the condenser section of the heat pipe within the dry ice storage tank, located above the condenser end of the heat pipe, and fixed together with a fixing device. The gas delivery pipe has multiple inlets to facilitate the entry of CO2 gas. Along the flow direction of the fluid within the condenser end, the flow area of ​​the inlets gradually decreases.

2. The loop heat pipe system as described in claim 1, characterized in that, The heat pipe evaporation sections are arranged at fixed points in the coal pile, and the outer side is equipped with ring fins to enhance heat transfer.

3. The loop heat pipe system as described in claim 1, characterized in that, The condenser section is designed in a bow shape.

4. The loop heat pipe system as described in claim 1, characterized in that, The gas pipeline has multiple branch pipes in the coal pile, and each branch pipe is equipped with a control valve to control the CO2 output of the branch pipe.

5. The loop heat pipe system as described in claim 4, characterized in that, When spontaneous combustion is detected at a certain location in the coal pile at the monitoring point, the control valve of the branch pipe closest to that location is opened, thereby rapidly outputting CO2.

6. The loop heat pipe system as described in claim 5, characterized in that, The CO2 output is greatest at the location of spontaneous combustion, and the amount of CO2 output from the branch pipe decreases with increasing distance from the location of spontaneous combustion.

7. The loop heat pipe system as described in claim 6, characterized in that, The CO2 output is controlled by adjusting the valve opening.

8. The loop heat pipe system as described in claim 1, characterized in that, Spontaneous combustion can be determined by detecting the gases produced during combustion or by measuring the temperature.

9. The loop heat pipe system as described in claim 1, characterized in that, The dry ice storage chamber and gas pipeline are covered with heat-insulating material.

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