A collaborative processing system for underground mine heat damage control and geothermal energy development and utilization

Abstract

The invention discloses a coordinated processing system for underground mine heat damage control and geothermal energy development and utilization. The cold water supply and pressure reduction system comprises a cold water collection pool (1) and a water supply pipeline (2) located in the upper constant temperature zone of the mine. The water supply pipeline (2) is arranged along the shaft and goes down to the middle section of the deep part where the temperature needs to be reduced. The heat exchange pipe network (16) of the heat insulation support and heat exchange system (S) is a mutually interpenetrating mesh structure composed of hollow metal heat exchange pipes with extremely fast heat conduction speed. The water inlet of the water pump (8) is connected to the water outlet (18) of the heat exchange pipe network by an insulation pipe (9). The water outlet of the water pump (8) is discharged from the insulation water pipe (9) along the shaft to a surface heat exchanger (10) and finally enters the surface heating system. The present invention supplies cold water from a cold water collection pool in the upper constant temperature zone of a mine to a deep middle section operation site that needs cooling through a heat exchange pipe network, thereby effectively controlling the ambient temperature of the operation site below the wet bulb temperature of 27°C. This can both control the ambient temperature of the high-temperature operation area and recycle geothermal resources, thereby achieving the purpose of saving energy.

Description

Technical Field

[0001] The invention belongs to the technical field of ventilation and cooling of underground mines, and in particular relates to a method for controlling thermal damage of surrounding rocks of underground mines with high original rock temperature and utilizing geothermal energy. Background Art

[0002] As the mining depth of underground mines continues to increase, the original rock temperature at the operation site gradually increases. On average, the original rock temperature increases by 1 to 3 degrees Celsius for every 100 meters of mining depth. The high ground temperature and the heat of air compression, ore oxidation, mechanical equipment heat dissipation, filling hydration heat and other heat damages have caused the underground working environment temperature to gradually increase. The high temperature and high humidity in the underground environment has become a major obstacle to the development of deep mineral resources.

[0003] Traditional mine cooling measures include non-artificial refrigeration and artificial refrigeration. Non-artificial refrigeration includes wind-increasing cooling and personal protection. However, for mines with an ambient wet-bulb temperature of more than 35°C, the wind-increasing cooling effect is significantly reduced, and with the increase in air volume, the ventilation energy consumption increases significantly, resulting in poor economic results. Personal protection requires workers to wear cooling vests during work, which increases the workload of workers and is difficult to promote. Artificial refrigeration requires the addition of mechanical refrigeration units, which have a significant cooling effect, but the refrigeration equipment consumes a lot of electricity, and the refrigeration unit is difficult to adapt to the high vibration, high dust and dynamically changing on-site environment caused by underground blasting. The system has high construction and operating costs and a short service life, which is difficult for general mining companies to bear.

[0004] In order to control the heat damage in mines, the article "Calculation of temperature field in high-temperature heat-damaged tunnels and selection principles of insulation layer" published in Science and Technology (2016, 22 (12)) calculated the temperature field of high-temperature heat-damaged tunnels, added a rigid polyurethane foam insulation layer between the surrounding rock temperature circle and the concrete lining, and performed numerical calculations on the design parameters of the insulation layer, achieving a good cooling effect. However, this technology only uses insulation without introducing a cold source, so the cooling effect is limited.

[0005] The temperature field of the mine extending from the surface to the deep is divided into variable temperature zone, constant temperature zone and increasing temperature zone. The operation sites of deep high-temperature mines are all in the increasing temperature zone. However, in the early stage of underground mining, some projects are often in the variable temperature zone and constant temperature zone. The original rock temperature at this location is relatively low. The temperature in the constant temperature zone is approximately equal to the annual average temperature of the mine location. The temperature of the tunnel water in the constant temperature zone is much lower than the deep ambient temperature, which provides a natural refrigerant and heat exchange carrier for the heat damage control in the deep mining area. Summary of the invention

[0006] The purpose of the present invention is to address the prominent heat damage problems in deep mines, the poor working environment for workers, the low labor efficiency and prominent safety hazards, as well as the technical problems such as the poor cooling effect of the existing ventilation and cooling systems, high system operation energy consumption, and short equipment life. An underground mine heat damage control and geothermal energy development and utilization collaborative processing system with a simple structure, reliable operation, good cooling effect and the ability to convert heat damage into geothermal resources is proposed.

[0007] In order to achieve the above-mentioned purpose of the present invention, the present invention adopts the following technical scheme to implement a coordinated processing system for underground mine heat damage control and geothermal energy development and utilization:

[0008] The invention discloses a coordinated processing system for underground mine heat damage control and geothermal energy development and utilization, comprising a cold water supply and pressure reduction system, a heat insulation support and heat exchange system, and a heat recovery system:

[0009] The cold water supply and pressure reduction system includes a cold water collection tank and a water supply pipe, a pressure regulating valve, and a filter located in the upper constant temperature zone project of the mine. The water inlet of the water supply pipe is connected to the cold water collection tank. The water supply pipe is arranged along the wellbore down to the deep middle section that needs to be cooled and is connected in series with the pressure regulating valve and the filter; the water outlet of the filter is connected to the water inlet of the heat exchange network; the cold water collection tank is used to collect upper cold water.

[0010] The insulation support and heat exchange system are arranged along the direction of the tunnel, including ordinary concrete support layer, heat exchange pipe network, and insulation support concrete. The ordinary concrete support layer is formed by spraying ordinary concrete with a thickness of not less than 10 cm on the surface of the original rock of the excavated tunnel. The heat exchange pipe network is laid on the ordinary concrete support layer. The insulation support concrete is formed by spraying insulation concrete on the ordinary concrete support layer and the heat exchange pipe network. The heat exchange pipe network is composed of a mesh structure of hollow metal heat exchange pipes with extremely fast heat conduction speed. The original rock surface of the tunnel includes the side wall and the top of the tunnel. The heat exchange pipe network is attached to the side wall and the top of the tunnel along the surface of the ordinary concrete support layer of the tunnel. The thickness of the insulation support concrete is not less than 10 cm, generally in the range of 10-13 cm. The cold water in the heat exchange pipe network absorbs the heat continuously released from the surrounding of the tunnel in the pipeline, blocking its transmission to the air in the tunnel. The insulation system composed of ordinary concrete support layer and insulating support concrete can not only provide closed and fitting heat exchange conditions for the heat exchange network, but also further prevent the heat that is not absorbed by the low-temperature water in the network from spreading to the air in the tunnel, allowing the heat to be gradually absorbed by the cold water in the heat exchange network, thereby achieving the purpose of lowering the tunnel temperature.

[0011] The heat recovery system is composed of a water pump, an insulated water pipe and a surface heat exchanger. The water inlet of the water pump is connected to the outlet of the heat exchange network by an insulated pipe. The water outlet of the water pump is discharged from the insulated water pipe along the wellbore to the surface heat exchanger and finally enters the surface heating system. The high-temperature hot water in the heat exchange system is discharged to the surface through the water pump and the insulated water pipe through the wellbore and enters the surface heat exchanger for utilization.

[0012] Furthermore, it is also provided with a monitoring system, which consists of a surface main control computer, a water inlet flowmeter, a first water temperature meter, a water outlet flowmeter, and a second water temperature meter; the water inlet flowmeter is arranged on the water supply pipe beside the water inlet of the heat exchange network of the thermal insulation support and heat exchange system, and the water outlet flowmeter is arranged on the water supply pipe beside the water outlet of the heat exchange network of the thermal insulation support and heat exchange system; the first water temperature meter is installed on the water supply pipe between the water inlet flowmeter and the water inlet of the heat exchange network of the thermal insulation support and heat exchange system, and the second water temperature meter is installed on the water supply pipe between the water outlet of the heat exchange network of the thermal insulation support and heat exchange system and the water outlet flowmeter; the surface main control computer is connected to the water inlet flowmeter, the first water temperature meter, the water outlet flowmeter, and the second water temperature meter through communication cables respectively.

[0013] As the length of the heat exchange network increases and the resistance of the pipeline increases, the water pressure in the pipeline will not be enough to ensure the flow of water in the heat exchange network. Therefore, the lower limit alarm value of the flow is set in the monitoring system. When the flow in the heat exchange network is less than the lower limit alarm value, the monitoring system sends a command to the pressure regulating valve to adjust the water pressure in the water pipe to ensure the stability of the water volume in the system. According to the temperature difference between the first water thermometer and the second water thermometer and the flow of the flow meter, the heat exchange of the thermal insulation support and the heat exchange system is calculated; according to the flow difference between the water inlet flow meter and the water outlet flow meter, monitor whether there is water leakage in the thermal insulation support and the heat exchange system.

[0014] Preferably, a pressure gauge is installed on the water supply pipe between the pressure regulating valve and the filter, and the surface main control machine is connected to the pressure gauge via a communication cable; the pipe diameter of the heat exchange pipe network is 3.5-5 cm.

[0015] Preferably, the heat exchange pipe network is assembled in sections along the axial direction of the tunnel, the length of each section is equal to the length of a cycle footage of the blasting tunnel, the width of each section is 1.5-2m, and the water outlets and water inlets between adjacent sections are tightly connected by quick connectors. Each section is quickly connected to the front section through a reserved quick connector, the newly added pipe network water inlet is connected to the front pipe network water outlet, and the newly added pipe network water outlet is connected to the water supply pipe network of the heat recovery system.

[0016] The pressure gauge of the present invention is provided with a pressure sensor, and the first water thermometer and the second water thermometer are provided with temperature sensors respectively.

[0017] The underground mine heat damage control and geothermal energy development and utilization coordinated processing system of the present invention adopts the above technical solution, which has the following beneficial effects:

[0018] (1) The cold water in the cold water collection pool in the upper constant temperature zone of the mine is supplied to the deep middle section of the work site where cooling is required through the heat exchange pipe network, so that the ambient temperature of the work site can be effectively controlled below the wet bulb temperature of 27°C. As the temperature of the cold water supplied in the heat exchange pipe network decreases, the ambient temperature of the work site can be further reduced.

[0019] (2) Through the heat exchange effect of thermal insulation support and heat exchange system, the water temperature difference between the inlet and outlet of the heat exchange network can reach more than 10°C, and as the coverage length of the network increases, the outlet water temperature of the heat exchange network gradually increases and can reach the temperature of the original rock temperature at the location of the tunnel.

[0020] (3) It achieves effective control of underground heat damage and recovers geothermal energy. The cost of ventilation and cooling is reduced by more than 80% compared with traditional refrigeration and wind-increased cooling, and the system is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural connection diagram of a coordinated processing system for underground mine heat damage control and geothermal energy development and utilization of the present invention;

[0022] Figure 2 It is a longitudinal cross-sectional view of the arrangement of the heat insulation support and heat exchange system S adopted by the present invention on the top and wall of the original rock of the excavated tunnel;

[0023] Figure 3 yes Figure 2 Longitudinal section along AA direction.

[0024] The accompanying drawings are marked as follows: 1-cold water collection tank; 2-water supply pipeline; 3-pressure regulating valve; 4-filter; 5-water inlet flowmeter; 6-first water thermometer; 5'-water outlet flowmeter; 6'-second water thermometer; S-thermal insulation support and heat exchange system; 8-water pump; 9-insulated water pipe; 10-surface heat exchanger; 11-surface main control computer; 12-communication cable; 13-pressure gauge; 14-ordinary concrete support layer; 15-thermal insulation support concrete; 16-heat exchange pipe network; 17-water inlet of heat exchange pipe network; 18-water outlet of heat exchange pipe network; 19-original rock surface of tunnel. DETAILED DESCRIPTION

[0025] In order to further describe the present invention, a coordinated processing system for underground mine heat damage control and geothermal energy development and utilization of the present invention is described in more detail below in conjunction with the accompanying drawings.

[0026] Depend on Figure 1The structural connection diagram of the underground mine heat damage control and geothermal energy development and utilization coordinated processing system of the present invention is shown in combination with Figure 2 , Figure 3 It can be seen that the underground mine heat damage control and geothermal energy development and utilization coordinated processing system of the present invention is composed of a cold water supply and pressure reduction system, a thermal insulation support and heat exchange system, a heat recovery system, and a monitoring system:

[0027] The cold water supply and pressure reduction system comprises a cold water collection tank 1 and a water supply pipe 2, a pressure regulating valve 3, and a filter 4 located in the upper constant temperature zone project of the mine. The water inlet of the water supply pipe 2 is connected to the cold water collection tank 1. The water supply pipe 2 is arranged along the wellbore down to the deep middle section that needs to be cooled and is connected in series with the pressure regulating valve 3 and the filter 4; the water outlet of the filter 4 is connected to the water inlet 17 of the heat exchange network; a pressure gauge 13 is installed on the water supply pipe 2 between the pressure regulating valve 3 and the filter 4, and the surface main control computer 11 is connected to the pressure gauge 13 via a communication cable 12.

[0028] The heat insulation support and heat exchange system S is arranged along the direction of the tunnel, including ordinary concrete support layer 14, heat exchange pipe network 16, and heat insulation support concrete 15. The ordinary concrete support layer 14 is formed by spraying ordinary concrete with a thickness of not less than 10 cm on the original rock surface 19 of the excavated tunnel. The heat exchange pipe network 16 is laid on the ordinary concrete support layer 14. The heat insulation support concrete 15 is formed by spraying 10 cm thick insulation concrete on the ordinary concrete support layer 14 and the heat exchange pipe network 16. The heat exchange pipe network 16 is composed of a hollow metal heat exchange pipe with a diameter of 4 cm and a very fast heat conduction speed, which is composed of a mesh structure that is interconnected. It is attached to the side wall and top of the tunnel along the surface of the ordinary concrete support layer 14 of the tunnel. The heat exchange pipe network 16 is assembled in sections along the axial direction of the tunnel. The length of each section is equal to the length of one cycle of the blasting tunnel. The width of each section is 1.5-2m. The water outlets and water inlets between adjacent sections are tightly connected by quick connectors.

[0029] The heat recovery system is composed of a water pump 8, an insulated water pipe 9 and a surface heat exchanger 10. The water inlet of the water pump 8 is connected to the water outlet 18 of the heat exchange network by the insulated pipe 9. The water outlet of the water pump 8 is discharged from the insulated water pipe 9 along the wellbore to the surface heat exchanger 10 and finally enters the surface heating system.

[0030] The monitoring system comprises a surface main control computer 11, a water inlet flow meter 5, a first water temperature meter 6 and a water outlet flow meter 5 ’ 、Second water temperature meter 6 ’ Composition; the water inlet flowmeter 5 is arranged on the water supply pipe 2 next to the heat exchange network water inlet 17 of the heat exchange system S, and the water outlet flowmeter 5 ’The first water thermometer 6 is installed on the water supply pipe 2 beside the water outlet 18 of the heat exchange pipe network of the heat insulation support and heat exchange system S; the first water thermometer 6 is installed on the water supply pipe 2 between the water inlet flowmeter 5 and the water inlet 17 of the heat exchange pipe network of the heat insulation support and heat exchange system S, and the second water thermometer 6 ’ Installed at the outlet 18 of the heat exchange pipe network and the outlet flow meter 5 of the heat insulation support and heat exchange system S ’ The surface master machine 11 communicates with the water inlet flow meter 5, the first water temperature meter 6 and the outlet flow meter 5 through the communication cable 12 respectively. ’ 、Second water temperature meter 6 ’ connect.

[0031] As the length of the heat exchange network 16 increases and the pipe resistance increases, the water pressure in the water supply pipe 2 will not be sufficient to ensure the flow of water in the heat exchange network 16. Therefore, a lower limit alarm value of the flow rate is set in the monitoring system. When the flow rate in the heat exchange network 16 is less than the lower limit alarm value, the monitoring system sends a command to the pressure regulating valve 3 to adjust the water pressure in the water pipe to ensure the stability of the water volume in the system; according to the first water thermometer 6 and the second water thermometer 6 ’ The temperature difference and the flow rate of the flow meter are used to calculate the heat exchange capacity of the thermal insulation support and the heat exchange system S; and the flow difference between the water inlet flow meter 5 and the water outlet flow meter 5' is used to monitor whether there is water leakage in the thermal insulation support and the heat exchange system S.

[0032] Assume: the flow rate of the water inlet flow meter 5 is m, the temperature of the first water thermometer 6 is T1, and the temperature of the second water thermometer 6 is T2. ’ The temperature is T2, the specific heat capacity of water is c, and the heat collected by the insulation support and heat exchange system S is calculated according to the following formula: Q = c*m*(T2-T1).

Claims

1. A collaborative processing system for underground mine heat damage control and geothermal energy development and utilization, characterized in that It includes cold water supply and pressure reduction system, thermal insulation support and heat exchange system(S), heat recovery system: The cold water supply and pressure reduction system comprises a cold water collection pool (1) and a water supply pipe (2), a pressure regulating valve (3), and a filter (4) located in the upper constant temperature zone of the mine. The water inlet of the water supply pipe (2) is connected to the cold water collection pool (1). The water supply pipe (2) is arranged along the shaft down to the middle section where the temperature needs to be reduced and is connected in series with the pressure regulating valve (3) and the filter (4); the water outlet of the filter (4) is connected to the water inlet (17) of the heat exchange pipe network. The heat insulation support and heat exchange system (S) is arranged along the direction of the tunnel, and comprises an ordinary concrete support layer (14), a heat exchange pipe network (16), and heat insulation support concrete (15); the ordinary concrete support layer (14) is formed by spraying ordinary concrete with a thickness of not less than 10 cm on the original rock surface (19) of the excavated tunnel; the heat exchange pipe network (16) is laid on the ordinary concrete support layer (14); the heat insulation support concrete (15) is formed by spraying insulation concrete on the ordinary concrete support layer (14) and the heat exchange pipe network (16); the heat exchange pipe network (16) is a mesh structure composed of hollow metal heat exchange pipes with extremely high heat conduction speed, which are interconnected; The heat recovery system is composed of a water pump (8), an insulated water pipe (9) and a surface heat exchanger (10). The water inlet of the water pump (8) is connected to the heat insulation support and the heat exchange pipe network outlet (18) of the heat exchange system (S) by the insulated pipe (9). The water outlet of the water pump (8) is discharged from the insulated water pipe (9) along the wellbore to the surface heat exchanger (10) and finally enters the surface heating system.

2. The underground mine heat damage control and geothermal energy development and utilization coordinated processing system as claimed in claim 1, characterized in that: It is also provided with a monitoring system, which comprises a surface main control machine (11), a water inlet flow meter (5), a first water temperature meter (6) and a water outlet flow meter (5 ’ )、Second water thermometer(6 ’ ) composition; the water inlet flow meter (5) is arranged on the water supply pipe (2) next to the water inlet (17) of the heat exchange network of the heat exchange system (S), and the water outlet flow meter (5 ’ ) is arranged on the water supply pipe (2) beside the water outlet (18) of the heat exchange pipe network; the first water temperature meter (6) is installed on the water supply pipe (2) between the water inlet flow meter (5) and the water inlet (17) of the heat exchange pipe network, and the second water temperature meter (6 ’ ) is installed between the outlet of the heat exchange pipe network (18) and the outlet flow meter (5 ’ ) between the water supply pipe (2); the surface master control machine (11) is respectively connected to the water inlet flow meter (5), the first water temperature meter (6) and the water outlet flow meter (5) through the communication cable (12). ’ )、Second water thermometer(6 ’ )connect.

3. The underground mine heat damage control and geothermal energy development and utilization coordinated processing system as claimed in claim 1, characterized in that: The monitoring system sets a lower limit alarm value for the flow rate. When the flow rate in the heat exchange pipe network (16) is less than the lower limit alarm value, the monitoring system sends a command to the pressure regulating valve (3) to adjust the water pressure in the water pipe to ensure the stability of the water volume in the system.

4. A coordinated processing system for underground mine heat damage control and geothermal energy development and utilization as claimed in claim 1, 2 or 3, characterized in that: A pressure gauge (13) is installed on the water supply pipe (2) between the pressure regulating valve (3) and the filter (4), and the surface main control machine (11) is connected to the pressure gauge (13) via a communication cable (12).

5. The underground mine heat damage control and geothermal energy development and utilization coordinated processing system as claimed in claim 4, characterized in that: The diameter of the heat exchange pipe network (16) is 3.5-5 cm.

6. The underground mine heat damage control and geothermal energy development and utilization coordinated processing system as claimed in claim 5, characterized in that: The heat exchange pipe network (16) is assembled in sections along the axial direction of the tunnel, the length of each section is equal to the length of one cycle of blasting tunnel, the width of each section is 1.5-2m, and the adjacent water outlets and water inlets are tightly connected by quick connectors.

7. The underground mine heat damage control and geothermal energy development and utilization coordinated processing system as claimed in claim 6, characterized in that: The thickness of the heat-insulating support concrete (15) is 10-13 cm.

8. The underground mine heat damage control and geothermal energy development and utilization coordinated processing system as claimed in claim 2, characterized in that: The thickness of the heat-insulating support concrete (15) is 10-13 cm; the diameter of the heat exchange pipe network (16) is 3.5-5 cm; the heat exchange pipe network (16) is composed of a plurality of heat exchange pipe network units connected in series, the width of each heat exchange pipe network unit is 1.5-2 m, and the water outlets and water inlets between adjacent ones are tightly connected by quick connectors; a pressure gauge (13) is installed on the water supply pipe (2) between the pressure regulating valve (3) and the filter (4), and the surface main control machine (11) is connected to the pressure gauge (13) via a communication cable (12).

9. The underground mine heat damage control and geothermal energy development and utilization coordinated processing system as claimed in claim 8, characterized in that: The monitoring system sets a lower limit alarm value for the flow rate. When the flow rate in the heat exchange pipe network (16) is less than the lower limit alarm value, the monitoring system sends a command to the pressure regulating valve (3) to adjust the water pressure in the water pipe to ensure the stability of the water volume in the system; according to the first water temperature meter (6) and the second water temperature meter (6 ’ ) and the flow rate of the flow meter, calculate the heat exchange capacity of the thermal insulation support and the heat exchange system (S); and monitor whether there is water leakage in the thermal insulation support and the heat exchange system (S) according to the flow difference of the water inlet flow meter (5) and the water outlet flow meter (5').

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