Direct supply type shaft anti-freezing system

Abstract

The utility model relates to a direct supply type shaft anti-freezing system, which is used for obtaining heat from mine return air and directly supplying heat to a shaft of a mine, and comprises a return air heat taking part, a heat medium circulating part and a shaft part, and a return air heat extraction unit for extracting heat from the mine return air to heat the heat medium circulating in the heat medium circulating unit, the heat medium circulating unit circulating the heat medium between the return air heat extraction unit and the shaft unit so as to supply heat to the shaft unit, the shaft unit being provided in the vicinity of the shaft, and the shaft unit being provided in the vicinity of the shaft. And a heat exchanger that exchanges heat between the heat medium and fresh air introduced from the outside, and introduces the fresh air subjected to the heat exchange into the shaft.

Description

Technical Field

[0001] This utility model relates to an antifreeze system for mine shafts, and in particular to a direct-supply shaft antifreeze system for supplying heat to mine shafts. Background Technology

[0002] According to relevant regulations, during the construction of coal mines and other mines, it is explicitly required that the air temperature below the mine's air intake must be maintained above 2°C. Previously, to prevent the shaft from freezing, coal-fired boiler rooms were typically used as the heat source to supply heat to the mine. In recent years, due to the widespread application of clean energy heating technologies, coal-fired boiler rooms are no longer the sole source of heat for mines; the selection of heat sources is gradually shifting towards dual-source and multi-source complementary approaches.

[0003] In recent years, with the continuous advancement of national energy conservation and emission reduction policies and increasingly stringent environmental protection requirements for coal mines, the recycling and utilization of low-temperature waste heat resources in coal mines to achieve clean heating in mining areas has attracted widespread attention from coal enterprises. In particular, due to the large volume, stable temperature, high relative humidity, and high enthalpy of mine return air, it contains a large amount of high-quality low-temperature heat energy, which is a waste heat resource with extremely high utilization value. Therefore, it is considered to use the waste heat of mine return air as a heat source to design a shaft antifreeze system.

[0004] Currently, there are three main technical routes for utilizing waste heat from coal mine return air (exhaust air): The first is the "spray-type heat pump" route, which involves arranging a spray-type diffusion tower above the return air shaft. The sprayed water directly contacts the return air for heat exchange, and the low-grade water after heat exchange enters the evaporator of the heat pump unit. The heat pump unit then produces high-temperature hot water after performing work. The second is the "direct-evaporation return air heat pump" route, which uses a heat exchanger to achieve indirect heat exchange between the refrigerant (Freon) and the return air. Utilizing the low boiling point of Freon, it absorbs heat from the return air and then enters the condenser after being processed by the compressor to heat the water. The third is the "direct-cooling deep enthalpy heat extraction heat pump" route, which involves arranging a partitioned heat exchanger above the return air heat extraction platform (return air heat extraction section). The circulating heat medium in the partitioned heat exchanger is ethylene glycol antifreeze. The antifreeze indirectly exchanges heat with the return air, and the antifreeze after heat exchange enters the evaporator of the heat pump unit to produce high-temperature hot water. Utility Model Content

[0005] Problems to be solved by the utility model

[0006] The temperature of mine return air is generally above 15℃. The three existing technical approaches all employ heat pumps to extract heat from the return air, using a compressor to consume electrical energy to convert low-quality heat into high-quality hot water (e.g., 40℃~50℃). The heat from this hot water is then used to heat the fresh air for mine shaft antifreeze. This process involves multiple heat exchange stages, making it complex. Furthermore, heat pump systems suffer from high installed power, high operating costs, and significant maintenance requirements. Continuing to design mine shaft antifreeze systems using traditional heat source design methods will lead to problems such as large heat source selection, large pipe diameters, high investment costs, and high operating energy consumption.

[0007] Solution for solving the problem

[0008] A direct-supply shaft antifreeze system is provided for obtaining heat from mine return air and directly supplying heat to the mine shaft. It is characterized by comprising a return air heat extraction section, a heat medium circulation section, and a shaft section. The return air heat extraction section is located near the mine return air diffuser tower and is used to obtain heat from the mine return air to heat the heat medium circulating in the heat medium circulation section. The heat medium circulation section circulates the heat medium between the return air heat extraction section and the shaft section, thereby supplying heat to the shaft section. The shaft section is located near the shaft and allows the heat medium to exchange heat with fresh air introduced from the outside, and the fresh air that has undergone the heat exchange is then introduced into the shaft.

[0009] The direct-supply wellbore antifreeze system is characterized in that one or more return air heat exchangers are arranged in multiple layers in the return air heat extraction section.

[0010] The direct-supply shaft antifreeze system is characterized in that the return air heat exchanger reduces the wind speed of the mine return air to ≤2m / s.

[0011] The direct-supply wellbore antifreeze system is characterized in that the return air heat exchanger is a partitioned return air heat exchanger with a heat exchange capacity surplus coefficient of 1.15 to 1.25.

[0012] The direct-supply wellbore antifreeze system is characterized in that the heat medium pipeline of the heat medium circulation section adopts a closed-loop circulation method.

[0013] The direct-supply wellbore antifreeze system is characterized in that the heat medium circulation section further includes a liquid replenishment and pressure stabilization component, which is used to replenish the heat medium circulating in the heat medium circulation section and to release pressure when the hydraulic pressure in the heat medium circulation section exceeds a predetermined value.

[0014] The direct-supply wellbore antifreeze system is characterized in that the wellbore section further includes a backup heat source that can be quickly started, and the wellbore section adopts explosion-proof equipment.

[0015] The direct-supply wellbore antifreeze system is characterized in that the pipeline through which the heat medium flows uses pipes and fittings with non-galvanized or zinc-free inner walls.

[0016] Effects of the utility model

[0017] The direct-supply shaft antifreeze system of this utility model can achieve shaft antifreeze by recovering the waste heat of the mine return air and directly supplying heat to the mine shaft. It has a simple structure, high system energy efficiency, and has the advantages of small heat source selection, small pipe diameter, low investment cost, and low operating energy consumption. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating a direct-supply wellbore antifreeze system according to an embodiment. Detailed Implementation

[0019] To make the objectives, technical solutions and advantages of this utility model clearer, the embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0020] <Example>

[0021] Mine return air is characterized by large air volume, stable air temperature, high relative humidity, and good continuity. It is a good low-temperature waste heat resource. The waste heat in the return air is extracted through the return air heat exchanger to produce hot water, which is then sent to the wellhead air heating unit in the wellhead heating chamber by the circulating water pump, which can meet the heating needs for wellhead antifreeze.

[0022] The following is for reference Figure 1 This invention relates to a direct-supply wellbore antifreeze system. Figure 1 This is a schematic diagram illustrating a direct-supply wellbore antifreeze system according to an embodiment.

[0023] The direct-supply wellbore antifreeze system involved in this embodiment includes: a return air heating platform (return air heating unit 1), a heat medium circulation unit 2, a wellhead room (wellbore unit 3), a detection unit (not shown), and a control unit.

[0024] The return air heat exchange unit 1 is located above or near the return air diffusion tower 6 in the mine, and a fan 61 is installed inside the return air diffusion tower. The return air diffusion tower 6 is located at the return air outlet of the mine, and its main function is to dilute and diffuse the mine return air. When the return air rises from the bottom of the mine to the return air outlet, the high-concentration, high-temperature return air is mixed with the surrounding air through the dispersion effect of the return air diffusion tower 6, thereby reducing the concentration and temperature of the return air and reducing environmental pollution.

[0025] The return air heat exchange unit 1 is a highly efficient energy recovery mechanism, primarily used for heating or warming by utilizing the heat energy in the mine return air. The return air heat exchange unit 1 includes a return air heat exchanger 11, dampers, and a maintenance passage (not shown). During the heat exchange process, the mine return air is introduced into the return air heat exchange platform through the return air duct of the return air diffuser tower 6 and enters the interior of the return air heat exchanger 11. In the return air heat exchanger 11, the mine return air exchanges heat with the heat medium within it. Since the return air itself has a certain temperature, it can transfer heat to the heat medium in the return air heat exchanger 11. During this process, the temperature of the mine return air decreases, while the temperature of the heat medium in the return air heat exchanger 11 increases, thereby extracting heat from the mine return air.

[0026] The core of the return air heat exchange unit 1 lies in the heat exchange structure of the return air heat exchanger 11. The return air heat exchanger 11 typically employs high-efficiency heat exchangers, such as plate, shell-and-tube, and finned tube types. Among these, a partitioned return air heat exchanger is preferred due to its high heat exchange performance and widespread application. More preferably, a partitioned return air heat exchanger with a heat exchange capacity surplus coefficient of 1.15 to 1.25 is used.

[0027] The indirect-access return air heat exchanger involved in this embodiment is preferably a shell-and-tube heat exchanger, and its working principle is based on the indirect-access effect of heat transfer. In the return air heat extraction section of a coal mine, the indirect-access return air heat exchanger uses a partition (usually a metal pipe wall) to exchange heat by separating two independent channels (heat source side and cold source side). Specifically, when the mine return air (as a heat source) flows through the heat source side of the indirect-access heat exchanger, the heat it carries is transferred to the heat medium on the cold source side through the metal pipe wall, thereby realizing heat recovery and transfer. In this process, the temperature of the return air decreases, and the temperature of the heat medium increases, thus enabling the heat medium to be used for heating, power generation, or other thermal energy utilization scenarios.

[0028] The base tube and shell of the return air heat exchanger 11 are generally made of metal materials with good thermal conductivity, such as copper, aluminum, or high-quality steel. These materials have good thermal conductivity, which can ensure that heat is efficiently transferred from the return air to the heat medium in the return air heat exchanger 11.

[0029] The heat transfer medium is preferably characterized by high specific heat, low density, low viscosity, good thermal conductivity, high safety, and environmental friendliness. The composition of the heat transfer medium is determined based on the performance of the return air heat exchanger and the operating temperature range of the heat exchange system. For example, ethylene glycol solution can be used, preferably an ethylene glycol solution.

[0030] When using ethylene glycol solution as the heat medium, it is preferable to select an industrial-grade corrosion-inhibiting ethylene glycol solution specifically formulated for air conditioning systems, with a preferred mass concentration of 25% to 30%. Correspondingly, it is preferable that the piping for the flow of the heat medium uses pipes and fittings with non-galvanized or zinc-free inner walls. Furthermore, it is preferable that the valves in the piping for the flow of the heat medium employ a metal hard-seal method, and that sealing measures are taken between the valves and pipe fittings.

[0031] Preferably, one or more return air heat exchangers 11 are provided in the return air heat extraction section 1. The return air heat exchangers 11 can be arranged in a single layer or in multiple layers. When multiple return air heat exchangers 11 are arranged in multiple layers, the wind speed of the mine return air at the return air heat exchangers 11 can be reduced to ≤2m / s, thereby achieving sufficient heat exchange.

[0032] The heat medium circulation section 2 circulates the heat medium between the return air heat extraction section 1 and the well section 3, thereby supplying heat to the well section 3. Preferably, the heat medium pipeline of the heat medium circulation section 2 adopts a closed-loop circulation method. The heat medium circulation section 2 includes a heat medium pipeline 21 and a circulation pump 211 is installed in the heat medium pipeline 21. The circulation pump 211 serves as the power source for the heat medium circulation and is preferably a variable frequency mechanical seal type or a shielded type circulation pump. Its performance parameters only need to meet the requirements of different working conditions and there are no special limitations.

[0033] The closed-loop circulation of the heat medium pipeline in the heat medium circulation section 2 reduces heat medium loss, but leakage is still unavoidable during long-term operation. Therefore, it is preferable that the heat medium circulation section 2 is equipped with a replenishment and pressure stabilization assembly 22 to replenish the heat medium circulating in the heat medium circulation section 2, wherein the replenishment volume of the replenishment and pressure stabilization assembly 22 accounts for 0.5% to 1.0% of the circulating volume of the heat medium. The replenishment and pressure stabilization assembly 22 is connected to the heat medium pipeline 21 via a replenishment pipeline 23, and preferably a replenishment pump 231, a pressure sensor P, and a safety relief valve 232 are installed in the replenishment pipeline 23. Based on the changes in system liquid pressure collected by the pressure sensor P, the power frequency is adjusted through logic calculation, thereby smoothly and steplessly adjusting the speed of the replenishment pump 231, that is, adjusting the replenishment volume, to achieve the purpose of relatively constant system pressure at the constant pressure point. For example, when the water pressure in the system is lower than a predetermined value, the control unit starts the replenishment pump 231 to replenish water; when the water pressure exceeds the predetermined value due to expansion, the control unit opens the safety relief valve 232 to release pressure and drain water. The replenishment pump 231 is preferably a variable frequency constant pressure replenishment pump.

[0034] The shaft section 3 employs explosion-proof equipment, including a heating unit 31, which is located in the shaft heating chamber. In the heating unit 31, a heated medium (not shown) flows into a pipeline inside the unit (not shown). Within the heating unit 31, the heated medium exchanges heat with fresh air introduced from the outside. The heated fresh air is then introduced into the mine shaft 7 by the heating unit 31, thus preventing the shaft 7 from freezing. Conversely, the heated medium, having undergone heat exchange, cools down and flows back to the return air heat extraction section 1 through the heated medium circulation section 2, entering the next heat exchange cycle.

[0035] The wellbore section 3 may also include a backup heat source (not shown) that can be quickly activated. Preferably, an electric heating device that meets explosion-proof requirements is used as the backup heat source. In the event of extreme temperatures, the control unit activates the backup heat source in an emergency to ensure the wellbore's antifreeze requirements.

[0036] The detection unit may include one or more temperature sensors T and one or more pressure sensors P. For example, the temperature sensor T may be installed in the return air diffuser tower 6 near the return air heat exchanger 1 to detect the temperature of the mine return air; it may also be installed on the exhaust outlet side of the return air heat exchanger 1 to detect the temperature of the return air after heat exchange; it may also be installed in the heat medium pipeline 21 to detect the temperature of the heat medium after heat exchange; or it may be installed in the shaft 7 to detect the shaft temperature. The pressure sensor P may be installed in the heat medium pipeline 21 to detect the pressure of the heat medium; or it may be installed in the replenishment pipeline 23 to detect the replenishment pressure.

[0037] The control unit centrally controls the overall operation of the direct-supply wellbore antifreeze system. For example, the detection unit monitors the temperature and pressure of the system and transmits the results to the control unit. The control unit processes and analyzes the received data, using preset algorithms and logic to determine whether to start, shut down, or adjust the system's operation. Additionally, the control unit can monitor the system's operating status based on the detection results to identify any malfunctions. In the event of a malfunction, the control unit activates the alarm system (not shown) to notify operators to take appropriate measures.

[0038] The following describes the overall heat exchange process of the direct-supply shaft antifreeze system. Generally, the temperature of mine return air is above 15℃. In this embodiment, the return air heat exchanger 11 is arranged in multiple layers, and the wind speed of the mine return air at the return air heat exchanger 11 is reduced to ≤2m / s. By increasing the heat exchange area of ​​the heat exchange plates, more thorough heat exchange is achieved, optimizing the heat exchange temperature difference to 3℃-5℃. That is, after the heat medium flowing through the return air heat exchanger 11 exchanges heat with the mine return air, the heat medium is heated to become a high-grade heat source, with a temperature close to the mine return air temperature, reaching 10℃-12℃. The high-grade heat medium is sent to the shaft section 3 via the heat medium circulation section 2. In the shaft section 3, the high-grade heat medium exchanges heat with the fresh air introduced from the outside. The fresh air is heated to above 2℃ and introduced into the shaft 7, thereby meeting the requirement in the "Coal Mine Safety Regulations" that the air temperature below the air inlet must be guaranteed to be above 2℃, achieving shaft antifreeze.

[0039] The direct-supply wellbore antifreeze system involved in this embodiment is simple, energy-efficient, and has low investment costs. It only consumes the energy of the water pump and the wellhead heating unit fan, and the operating cost is 20% of the original heat pump system heating method.

[0040] The above are merely embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A direct-supply shaft antifreeze system, used to obtain heat from mine return air and directly supply heat to the mine shaft, characterized in that, This includes the return air heat extraction section, the heat medium circulation section, and the wellbore section. The return air heat extraction unit is located near the return air diffusion tower of the mine and is used to extract heat from the mine return air to heat the heat medium circulating in the heat medium circulation unit. The heat medium circulation section circulates the heat medium between the return air heat extraction section and the well section, thereby supplying heat to the well section. The well section is located near the well shaft, allowing the heat medium to exchange heat with fresh air introduced from the outside, and the fresh air that has undergone the heat exchange is then introduced into the well shaft.

2. The direct-supply wellbore antifreeze system according to claim 1, characterized in that, The return air heat exchange section is provided with one or more return air heat exchangers arranged in multiple layers.

3. The direct-supply wellbore antifreeze system according to claim 2, characterized in that, The return air heat exchanger reduces the wind speed of the mine return air to ≤2m / s.

4. The direct-supply wellbore antifreeze system according to claim 2, characterized in that, The return air heat exchanger is a partitioned return air heat exchanger with a heat exchange capacity surplus coefficient of 1.15 to 1.

25.

5. The direct-supply wellbore antifreeze system according to claim 1, characterized in that, The heat medium pipeline of the heat medium circulation section adopts a closed circulation method.

6. The direct-supply wellbore antifreeze system according to claim 5, characterized in that, The heat medium circulation section also includes a liquid replenishment and pressure stabilization assembly. The fluid replenishment and pressure stabilization assembly is used to replenish the heat medium circulating in the heat medium circulation section and to release pressure when the hydraulic pressure in the heat medium circulation section exceeds a predetermined value.

7. The direct-supply wellbore antifreeze system according to claim 1, characterized in that, The wellbore section also includes a backup heat source that can be started up quickly. The well shaft section uses explosion-proof equipment.

8. The direct-supply wellbore antifreeze system according to claim 1, characterized in that, The pipelines that carry the heat medium use pipes and fittings with non-galvanized or zinc-free inner walls.

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