Dividing wall type mine return air waste heat utilization system

Abstract

The utility model relates to a dividing wall type mine return air waste heat utilization system, which is provided with a return air heat taking part, a heat exchange part and a heat exchange part, the heat pump part can realize heating and cooling functions; the cooling part can reduce the temperature of the heat exchange medium when refrigeration is needed; the heat storage part can store heat generated by solar energy, and the temperature of the heat exchange medium is increased when heating is needed; and the control part is used for controlling the whole dividing wall type mine return air waste heat utilization system, so that a heating mode and a refrigerating mode can be switched according to user requirements, and the operation states of the cooling part and the heat storage part are set according to the actual environment.

Description

Technical Field

[0001] This utility model relates to the technology of utilizing waste heat from mine return air, and in particular to a partitioned mine return air waste heat utilization system. Background Technology

[0002] In recent years, with the increasing global awareness of environmental protection and the development of green energy technologies, the mining industry is gradually shifting towards a green and intelligent direction. Against this backdrop, the utilization technology of waste heat from mine return air (exhaust air) has become a key component of green mine construction. It not only helps to save energy and reduce emissions, but also significantly reduces mine operating costs, improves energy efficiency, and reduces the impact on the external environment.

[0003] A mine shaft is a massive heat storage body, rich in geothermal resources. The air entering the mine continuously exchanges heat with the underground tunnels, mechanical equipment, and water systems, eventually reaching equilibrium with the mine's geothermal temperature. The relatively constant geothermal temperature ensures that the mine return air temperature remains largely constant throughout the year, minimally affected by external air temperatures. Furthermore, heat dissipation from underground mechanical equipment, coal dust oxidation, groundwater, and personnel all enters the mine return air. Therefore, mine return air is a stable and relatively high-quality low-grade heat and cold resource. Because the underground air remains at a constant temperature year-round, the mine return air temperature is higher than the outdoor ambient temperature in winter, serving as a low-grade heat source for return air heat pumps; in summer, the mine return air temperature is lower than the outdoor ambient temperature, serving as a cold source for return air heat pumps. Utility Model Content

[0004] Problems to be solved by the utility model

[0005] Although significant progress has been made in mine return air waste heat utilization technology in recent years, current technologies still need improvement in terms of integration and intelligence, with the aim of achieving functions such as real-time monitoring, fault early warning, and automatic adjustment. Furthermore, different climatic conditions place varying requirements on waste heat utilization technology. For example, in winter, waste heat from mine return air needs to be extracted for heating; in summer, it needs to be used for cooling the mine shaft; and in spring and autumn, it needs to be extracted for hot water. Therefore, it is hoped that the applicability and flexibility of the technology can be improved according to the specific needs of different climatic conditions. In addition, to maximize energy efficiency, it is desirable to integrate the mine return air waste heat utilization system with other mining facilities (e.g., thermal storage devices, solar thermal devices, electric heating devices, water treatment devices, etc.) to form a multi-energy complementary overall energy management system.

[0006] Solution for solving the problem

[0007] To address the aforementioned problems, this utility model provides a partitioned mine return air waste heat utilization system, characterized by comprising: a return air heat exchange unit for exchanging heat between the mine return air and a heat exchange medium; a heat pump unit capable of both heating and cooling; a cooling unit capable of lowering the temperature of the heat exchange medium when cooling is required; a heat storage unit capable of storing heat generated by solar energy and raising the temperature of the heat exchange medium when heating is required; and a control unit that controls the entire partitioned mine return air waste heat utilization system, enabling the switching between heating and cooling modes according to user needs, and setting the operating status of the cooling unit and the heat storage unit according to the actual environment.

[0008] According to the aforementioned interlocking mine return air waste heat utilization system, the system is characterized in that, in the heating mode, the return air heat extraction section and the heat storage section operate as heat source equipment for heating, while the cooling section does not operate; in the cooling mode, the return air heat extraction section and the cooling section operate as cold source equipment for cooling, while the heat storage section does not operate.

[0009] According to the aforementioned inter-wall mine return air waste heat utilization system, the heat pump unit comprises two or more first heat pump units and one or more second heat pump units. The first heat pump units are dual-condition heat pump units, which operate in both hot and cold conditions and are capable of both heating and cooling. The second heat pump units are total heat recovery type heat pump units, which are capable of recovering all heat for the production of high-temperature hot water. They have a first condenser and a second condenser. The second condenser can adjust its operating state to make its condensing temperature higher than that of the first condenser.

[0010] According to the aforementioned indirect-flow mine return air waste heat utilization system, in the heating mode, a portion of the heat exchange medium exchanges heat with the mine return air in the return air heat extraction section and flows to the heat pump section after its temperature rises; another portion of the heat exchange medium absorbs heat in the heat storage section and flows to the heat pump section after its temperature rises; the first heat pump unit further raises the temperature of the heat exchange medium, thereby making the heat exchange medium a high-grade heat source for heating.

[0011] According to the aforementioned interlocking mine return air waste heat utilization system, in the cooling mode, a portion of the heat exchange medium exchanges heat with the mine return air in the return air heat extraction section and flows to the heat pump section after its temperature decreases; another portion of the heat exchange medium dissipates heat in the cooling section and flows to the heat pump section after its temperature decreases. The first heat pump unit further reduces the temperature of the heat exchange medium, thereby making the heat exchange medium a high-grade cold source for refrigeration.

[0012] According to the aforementioned indirect-flow mine return air waste heat utilization system, its characteristic is that, in the heating mode, the second condenser does not operate, and the first condenser operates to produce the high-temperature hot water; in the cooling mode, the first condenser does not operate, and the second condenser operates, and the condensation temperature is increased by adjusting the operating state of the second condenser. The high-temperature hot water is produced by the second condenser.

[0013] According to the aforementioned inter-wall type mine return air waste heat utilization system, the control unit can also switch to hot water mode. In the hot water mode, the return air heat extraction unit and the heat storage unit operate, the cooling unit does not operate, the first heat pump unit does not operate, the second heat pump unit operates, and the high-temperature hot water is produced by the first condenser.

[0014] The indirect-wall mine return air waste heat utilization system is characterized by further comprising a liquid replenishment section, which is a water replenishment and pressure stabilization device used to replenish the heat exchange medium into the indirect-wall mine return air waste heat utilization system.

[0015] According to the aforementioned inter-wall mine return air waste heat utilization system, the liquid replenishment section includes a liquid replenishment tank, which is used to replenish the heat exchange medium under constant pressure.

[0016] According to the aforementioned inter-wall mine return air waste heat utilization system, the system is characterized in that a replenishment interface for replenishing the heat exchange medium is provided at the inlet of the circulation pump that circulates the heat exchange medium. The replenishment interface further includes a replenishment pressure regulating pump and a safety pressure relief valve. When the pressure at the replenishment interface is too low, the replenishment pressure regulating pump is activated to increase the replenishment pressure. When the pressure at the replenishment interface is too high, the safety pressure relief valve is opened to reduce the pressure.

[0017] Effects of the utility model

[0018] The indirect-wall mine return air waste heat utilization system of this invention enables remote monitoring and automated operation, which helps improve operation and maintenance efficiency and reduce labor costs. It also enhances the applicability and flexibility of the technology to adapt to specific needs under different climatic conditions. Further improvements: This indirect-wall mine return air waste heat utilization system can be integrated and combined with other energy technologies to construct a multi-energy complementary joint energy system. Through technological innovation and system integration, it can achieve complementary advantages and synergistic optimization among different energy sources, improving energy utilization efficiency and overall benefits.

[0019] The description in this specification is exemplary and explanatory only, and does not limit the scope of protection of this utility model. For better understanding and implementation, this utility model is described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram showing the overall structure of the partition wall type mine return air waste heat utilization system involved in this utility model.

[0021] Figure 2 This is a schematic diagram showing the heat-generating part involved in this utility model.

[0022] Figure 3 This is a schematic diagram showing the heat pump unit and user end involved in this utility model.

[0023] Figure 4 This is a schematic diagram showing the liquid replenishment section, cooling section, and heat storage section involved in this utility model.

[0024] Figure 5 This is a schematic diagram illustrating the heating mode involved in this utility model.

[0025] Figure 6 This is a schematic diagram illustrating the refrigeration mode involved in this utility model.

[0026] Explanation of reference numerals in the attached figures

[0027] 1: Heat extraction section; 2: Heat pump section; 3: Liquid replenishment section; 4: Cooling section; 5: Heat storage section; 6: Control section; 7: Circulation pipeline; 11: Return air heat exchanger; 21: First heat pump unit; 22: Second heat pump unit; 221: First condenser; 222: Second condenser. Detailed Implementation

[0028] The following detailed description of the embodiments of this utility model or the technical solutions in related technologies is provided with reference to the accompanying drawings. It should be understood that the content described below represents only a portion of the embodiments of this utility model, not all of them. Other embodiments obtained by those skilled in the art based on the following embodiments without inventive effort are also within the protection scope of this utility model.

[0029] [Interlocking Mine Return Air Waste Heat Utilization System]

[0030] Figure 1 This is a schematic diagram showing the overall structure of the indirect-wall mine return air waste heat utilization system according to this utility model. The indirect-wall mine return air waste heat utilization system according to this utility model includes a return air heat extraction unit 1, a heat pump unit 2, a liquid replenishment unit 3, a cooling unit 4, a heat storage unit 5, a control unit 6, and a circulation pipeline 7.

[0031] The return air heat exchange unit 1 is preferably a return air heat exchange platform or a return air heat exchange chamber, which is located near (e.g., above) the return air shaft in the mine and is used to exchange heat between the mine return air and the heat exchange medium. The mine return air from the return air shaft enters the return air heat exchange unit 1 through the return air diffusion tower, exchanges heat with the heat exchange medium in the heat exchanger, and is then discharged to the outside.

[0032] The heat pump section 2 preferably consists of one or more heat pump units, capable of both heating and cooling. The heat extraction medium, which has exchanged heat with the mine return air, exchanges heat with the heat pump working fluid in the heat pump section. The heat pump working fluid absorbs heat from the low-temperature heat source in the evaporator and evaporates into steam. Then, it is compressed into a high-temperature, high-pressure gas by the compressor, enters the condenser to release heat, and finally returns to the evaporator after being depressurized by the expansion valve. This cycle is repeated, thereby transferring heat from the low-temperature heat source to the high-temperature environment.

[0033] The replenishment unit 3 can be, for example, a water replenishment and pressure stabilization device, used to replenish the heat exchange medium (e.g., water, ethylene glycol solution) into the interlocking mine return air waste heat utilization system. The cooling unit 4 can be, for example, a closed-loop cooling tower, sometimes also called an evaporative air cooler, a closed cooling tower, or a sealed cooling tower, capable of cooling when needed to lower the temperature of the heat exchange medium. The heat storage unit 5 can be, for example, a solar thermal storage device, which is part of a solar thermal utilization system, storing the heat generated by solar energy during the day and capable of heating when needed to raise the temperature of the heat exchange medium. The control unit 6 provides unified control of the entire interlocking mine return air waste heat utilization system. The heat exchange medium circulates in the circulation pipeline 7, thereby transferring heat.

[0034] The structure and function of each part of the partition wall type mine return air waste heat utilization system of this utility model are described in detail below.

[0035] <Heat Extraction Section>

[0036] Figure 2 This is a schematic diagram illustrating the heat extraction unit involved in this utility model. The heat extraction unit 1 of this utility model is, for example, a return air heat extraction platform, which includes a return air heat exchanger 11 and, but not shown, a damper, a reverse air damper, a windbreak wall, and a maintenance passage. The specific design of the heat extraction unit 1 must at least consider the conditions for utilizing waste heat from the return air and the impact of mine ventilation.

[0037] Considering the conditions for utilizing waste heat from the mine's return air, the return air heat exchanger 11 is preferably a partitioned mine return air heat exchanger. The mine return air and the heat extraction medium flow through the two sides of the return air heat exchanger 11, thereby allowing heat to be transferred between the mine return air and the heat extraction medium for heat exchange.

[0038] After the heat exchange medium exchanges heat with the mine return air in the return air heat exchanger 11, it flows into the circulation pipeline 7 through the outlet pipe of the return air heat exchanger. Through the circulation pipeline 7, it flows to the heat pump section 2 (described later). In the heat pump section 2, it exchanges heat with the working fluid and then flows back to the return air heat exchanger 11 through the circulation pipeline 7 and the inlet pipe of the return air heat exchanger. This cycle is repeated to achieve the transfer of heat energy.

[0039] The return air heat exchanger 11 is located within the return air heat extraction platform and can be arranged in a single layer or multiple layers. When a multiple layer arrangement is used, the return air velocity during heat exchange can be reduced to ≤2m / s, thereby ensuring sufficient heat exchange. The heat exchange capacity margin of the return air heat exchanger 11 is preferably 1.15 to 1.25. The return air heat exchanger 11 has components for self-cleaning and defrosting functions, and the self-cleaning and defrosting time does not exceed 20% of the operating cycle. When the heat extraction temperature of the heat extraction section 1 is lower than 4°C, the control unit 6 controls the return air heat exchanger 11 to activate antifreeze measures (self-cleaning and defrosting functions).

[0040] This utility model's return air heating platform does not affect the normal operation of the mine ventilation fan or the stable air supply during reverse ventilation. The return air heating platform is connected to the mine's return air diffuser tower via a duct, with the duct interface designed to be streamlined to avoid vortex zones. The return air heating platform is equipped with vibration-damping structures such as corrugated pipes, ensuring that the noise level of the ventilation equipment meets relevant national regulations after the addition of the return air heating platform. A damper is provided at the connection between the return air heating platform and the duct to allow the duct to open and close, preventing icing. Since mine ventilation fans typically operate on a one-in-one standby configuration, the dampers and reverse ventilation dampers of this utility model's return air heating platform are designed to correspond one-to-one with the number of ventilation fans and their standby status in the mine.

[0041] Alternatively, two or more freely opening movable doors can be installed on the side wall of the return air heat exchange chamber to ensure the normal operation of the mine's reverse ventilation and ventilation system. The return air heat exchange platform is equipped with maintenance access space for easy inspection. Because the mine return air contains coal dust or other impurities, it easily forms dirt on the surfaces of heat exchangers, valves, and testing instruments; the maintenance access space facilitates regular cleaning and maintenance. To ensure the safety of the mine's intake air, the airflow passing through the return air heat exchange platform is kept under positive pressure.

[0042] Furthermore, the heat exchange resistance generated by the return air heat exchange platform of this invention during heat exchange is not greater than the resistance threshold (e.g., ≤200Pa). When the heat exchange resistance exceeds the resistance threshold, the control unit 6 controls the air door and the reverse air door to open, so as to ensure the safety of mine ventilation.

[0043] <Heat Pump Section>

[0044] Figure 3This is a schematic diagram showing the heat pump unit and user end involved in this utility model. The heat pump unit 2 of this utility model preferably includes one or more indirect heat pump units (hereinafter referred to as heat pump units), which include an evaporator, a compressor, a condenser, an expansion valve, and heat pump pipes. Typically, the heat pump working fluid circulates in the heat pump pipes to transfer heat energy. In heat extraction mode, the evaporator is located on the low-temperature side of the heat pump unit, and is preferably an indirect heat exchanger. In the evaporator, the heat pump working fluid exchanges heat with the heat extraction medium (low-temperature heat source) from the circulation pipe 7, absorbing heat from the heat extraction medium and evaporating into a gas. The compressor compresses the evaporated heat pump working fluid into a high-temperature, high-pressure gas, thereby increasing the energy level of the heat pump working fluid and raising its temperature to a level where heat can be effectively transferred. The condenser is located on the high-temperature side of the heat pump unit, and is preferably an indirect heat exchanger. In the condenser, the high-temperature, high-pressure heat pump refrigerant exchanges heat with the heating medium (e.g., building heating medium, well water supply), thereby cooling the refrigerant and condensing it into a liquid. An expansion valve, located downstream of the condenser and upstream of the evaporator, reduces the pressure of the heat pump refrigerant, causing it to expand and cool. After expanding and cooling, the refrigerant, now at a low temperature and low pressure, re-enters the evaporator to absorb heat, thus transferring thermal energy.

[0045] The above describes an embodiment in which the waste heat of the mine return air is transferred to the heating medium through three heat exchanges in the heat extraction mode. That is, the mine return air exchanges heat with the heat extraction medium in the return air heat exchanger 11, the heat extraction medium exchanges heat with the heat pump working fluid in the evaporator of the heat pump unit, and the heat pump working fluid exchanges heat with the heating medium in the condenser of the heat pump unit.

[0046] Furthermore, the above describes the heat exchange process in the winter heating mode. On the other hand, in the cooling mode, the control unit 6 controls the switching of various valves to change the flow direction of the medium in the pipeline, thereby causing the heating medium in the return air heat exchanger 11 to release heat to the mine return air, thus lowering its temperature. In the heat pump unit 2, the cooled heating medium exchanges heat with the heat pump working fluid in the condenser to absorb the heat from the heat pump working fluid, thereby cooling the heat pump working fluid; the cooled heat pump working fluid exchanges heat with the refrigerant in the evaporator to absorb the heat from the refrigerant, thereby cooling the refrigerant. The cooled refrigerant cools the user end, thereby achieving a cooling effect.

[0047] The number of heat pump units and their individual capacities in Heat Pump Section 2 should be selected to adapt to the annual variation of heat (cold) load and meet the requirements for seasonal and partial heat load operation. There should be no fewer than two units. When used for wellbore antifreeze purposes, the number of heat pump units should also ensure that if one unit fails, the remaining heat pump units can still meet the wellbore antifreeze requirements.

[0048] like Figure 3 As shown, in a preferred embodiment of this invention, the heat pump unit 2 comprises three heat pump units, wherein the first heat pump unit 21 is used for heating and cooling of buildings and mine shafts, and the second heat pump unit 22 is used for providing hot water. Compared to the first heat pump unit 21, the second heat pump unit 22 differs in that it has a first condenser 221 and a second condenser 222. In the first condenser 221 and the second condenser 222, the heat pump working fluid exchanges heat with the heating medium (here, water), thereby providing heated high-temperature hot water to the user.

[0049] Heat pump units are preferably products with a high coefficient of performance (COP) to reduce investment and operating costs.

[0050] Furthermore, all indirect heat exchangers are to operate in parallel, with a selection margin of 1.15 to 1.25 being preferred. The energy efficiency rating of the heat pump unit should be no lower than level two, preferably level one. Heat pump section 2 preferably incorporates energy-saving measures such as reducing the energy consumption of the circulating water pump.

[0051] <Rehydration Section>

[0052] Figure 4 This is a schematic diagram showing the liquid replenishment section, cooling section, and heat storage section involved in this utility model. The circulation pipeline of the indirect mine return air waste heat utilization system involved in this utility model includes a heat extraction pipeline, a heat pump pipeline, and a heat supply pipeline, preferably adopting a closed circulation. Although the pipeline adopts a closed circulation, leakage is still inevitable during long-term operation. Therefore, a liquid replenishment section 3 (water replenishment and pressure stabilization device) is also provided to replenish the heat exchange medium (including heat extraction medium, heat pump working medium, and heat supply medium) in the circulation pipeline 7.

[0053] To meet practical engineering requirements, the replenishment volume of the replenishment unit 3 is preferably 0.5% to 1.0% of the system circulation volume. The replenishment interface of the replenishment unit 3 for supplying heat exchange medium to the circulation pipeline 7 is preferably located at the suction inlet of the circulation pump in the circulation pipeline 7. When using a replenishment tank for constant pressure replenishment, it is preferable to directly replenish the heat exchange medium to the circulation pipeline 7 through an expansion tank. As shown in the figure, the replenishment unit 3 includes, for example, a fully automatic water softener and a replenishment tank. The replenishment tank is used to replenish the heat exchange medium under constant pressure.

[0054] When using other pressure-regulating methods, if the replenishment pressure is lower than the pressure at the replenishment interface, it is preferable to install a replenishment pressure-regulating pump (variable frequency constant pressure water replenishment pump). The replenishment section 3 is equipped with a variable frequency constant pressure water replenishment pump and a safety relief valve. If the pressure at the replenishment interface (replenishment pressure) is too low, the replenishment pressure-regulating pump starts to increase the replenishment pressure; if the replenishment pressure is too high, the safety relief valve opens to reduce the pressure.

[0055] The heat exchange medium may include a heat extraction medium, a heat pump working fluid, and a heating medium, preferably all three being of the same composition. The heat exchange medium is preferably characterized by high specific heat, low density, low viscosity, good thermal conductivity, high safety, and environmental friendliness. The specific composition of the heat exchange medium is determined based on the performance of the heat extraction section 1 and the heat pump section 2, as well as the operating temperature range of the system. For example, an ethylene glycol solution may be used as the heat exchange medium, preferably an industrial-grade corrosion-inhibiting ethylene glycol solution formulated specifically for air conditioning systems. Based on engineering practice, a mass concentration of ethylene glycol solution of 25%–30% is preferred.

[0056] In this case, it is strictly forbidden to use pipes and fittings with galvanized or zinc-containing inner walls in the circulation pipeline 7. The valves in the circulation pipeline 7 are preferably metal hard seals, and sealing measures are taken between the valves and pipe fittings. This is because ethylene glycol aqueous solution will produce flocculent precipitates when it comes into contact with zinc. The performance of the valves in the circulation pipeline 7 is very important, as it directly affects whether the system can operate normally, and it is also necessary to ensure no leakage under low-temperature conditions.

[0057] Cooling Section

[0058] This utility model's indirect-contact mine return air waste heat utilization system primarily serves heating purposes during the heating season (winter). When cooling is required during the non-heating season (summer), a techno-economic analysis is conducted based on the cooling load to avoid wasting the system's functionality. To improve cooling efficiency, this utility model's indirect-contact mine return air waste heat utilization system also includes a cooling section 4, which comprises one or more closed-loop cooling towers for cooling the heat exchange medium.

[0059] like Figure 1 As shown, the heat exchange medium enters the closed cooling tower from the top through a circulation pipeline and undergoes heat exchange with the interior and exterior via the heat exchanger. A fan guides the airflow, ensuring smooth heat exchange between the air and the heat exchange medium, thereby enhancing the heat dissipation effect.

[0060] <Heat Storage Section>

[0061] In this invention, the heat storage unit 5 is preferably a solar thermal energy storage device, capable of converting solar energy into heat energy and storing it for use when needed. Solar thermal energy storage devices are widely used in solar water heaters, centralized solar power (CSP) systems, building heating, and industrial process heating. A solar thermal energy storage device includes a collector, a heat storage unit, and a heat exchanger.

[0062] Solar collectors are used to absorb solar radiation and convert it into heat energy. Thermal storage devices contain the heat storage medium and have good insulation properties to reduce heat loss. The heat storage medium includes, for example, water, molten salt, paraffin wax, and other phase change materials (PCMs), preferably the same medium as the heat exchange medium.

[0063] A heat exchanger is located inside or outside the heat storage tank and is used to transfer heat from the heat storage medium to the heat exchange medium. Here, the heat exchanger can be, for example, a partitioned heat exchanger.

[0064] In addition, to ensure a continuous supply of heat energy, solar thermal storage devices can also be equipped with auxiliary heating sources, such as electric heaters or gas boilers, to provide additional energy when there is insufficient sunlight.

[0065] <Control Unit and Circulation Piping>

[0066] The control unit 6 of the partition-type mine return air waste heat utilization system of this utility model includes temperature sensors, pressure sensors, and other automated control devices for monitoring and adjusting the system's operating parameters to ensure efficient and stable operation. The control unit 6 can use various sensors to collect signals such as pressure, temperature, flow rate, and heat (cold) output. The control unit 6 employs a PLC or DCS control system, preferably using general-purpose configuration software for monitoring. The control unit 6 has the function of networking with the mine production monitoring system and can achieve remote monitoring and centralized control. An automatic air pressure monitoring device is installed in the heat exchange section 1 to measure the ventilation resistance of the return air heat exchange platform to prevent the pressure difference before and after the heat exchanger from exceeding the standard requirements.

[0067] The circulation pipeline 7 adopts a closed-loop circulation system, equipped with a mechanical seal type or a shielded type circulation pump, whose performance parameters meet the requirements of different operating conditions. The closed-loop system can reduce heat exchange medium loss, and the variable frequency control can significantly save system energy consumption.

[0068] Furthermore, heat pump units, fans, and other equipment are preferably low-noise devices, and the main equipment is preferably centrally located in a heat pump room. Preferably, the heat pump room is not located near buildings with high requirements for acoustic environment and vibration control. For equipment exposed outdoors, noise reduction measures should be taken when its noise level does not meet environmental noise standards. Heat pump units, fans, and other equipment are preferably equipped with vibration isolators, and flexible joints should be installed on the inlet and outlet pipes. Alternatively, a check valve can be installed at the outlet of the circulating pump, preferably a check valve with water hammer elimination function. Additionally, pipes that need to withstand equipment vibration are preferably supported by flexible supports and hangers. [Specific Implementation Examples]

[0070] Reference Figure 1 This invention describes a specific embodiment of the partition wall type mine return air waste heat utilization system. The main objective of this invention is to adjust the overall system layout to enable switching between heating and cooling modes according to user needs, and to set the operating status of the peak-shaving heat source (cooling section 4, heat storage section 5) according to the actual environment.

[0071] Specifically, in this invention, the heat pump unit 2 is located in a heat pump room and includes: two dual-condition heat pump units (first heat pump unit 21), each with an evaporator and a condenser, operating in dual-condition heating and cooling modes, i.e., heating in winter and cooling in summer; and a total heat recovery heat pump unit (second heat pump unit 22), which has an evaporator and two condensers (first condenser 221 and second condenser 222), capable of recovering all heat for the production of high-temperature hot water. The second condenser 222 can adjust its operating state to make its condensing temperature higher than that of the first condenser 221. Alternatively, depending on site requirements, it may include two or more dual-condition heat pump units, or one or more total heat recovery heat pump units.

[0072] One or more solar thermal energy storage devices are installed as heat storage units 5 on the roofs of the heat pump room, the return air heat extraction platform, or any other buildings within the mine site. Heat storage units 5 fully utilize solar thermal energy and store excess heat during the day, releasing heat as needed at night. Heat storage units 5 serve as a heat source connected in parallel with heat pump unit 2 (also called a parallel heat source or peak-shaving heat source), achieving complementarity between solar thermal energy and the mine return air heat source.

[0073] The return air heat exchanger of the return air heat extraction section 1 and the heat pump unit of the heat pump section 2 are circulated and connected via the circulation pipeline 7. The indirect mine return air waste heat utilization system adopts a closed-loop circulation and is equipped with a liquid replenishment section 3. A circulation pump is installed in the circulation pipeline 7, which serves as the power source for driving the circulation of the heat exchange medium. The liquid replenishment interface of the liquid replenishment section 3 is provided at the suction inlet of the circulation pump.

[0074] In this invention, the circulation pipeline includes a heat extraction pipeline, a heat pump pipeline, a heating pipeline, and a hot water pipeline. Each circulation pipeline includes an inlet pipe and a return pipe. The heat extraction pipeline is the main pipeline connecting the return air heat extraction unit 1 and the heat pump unit 2, also known as the mother pipeline. A heat extraction circulation pump is installed in the return pipe of the heat extraction pipeline. The medium flowing in the heat extraction pipeline is referred to as the heat extraction medium. The heat extraction circulation pump circulates the heat extraction medium in the heat extraction pipeline and flows into the heat pump unit 2. In the return pipe of the heat extraction pipeline, a thermometer and a pressure gauge are installed upstream of the heat extraction circulation pump to measure the temperature and pressure of the medium flowing back from the heat extraction unit 1 to the heat pump unit 2. In the inlet pipe of the heat extraction pipeline, a thermometer and a pressure gauge are installed near the heat pump unit 2 to measure the temperature and pressure of the medium flowing from the heat pump unit 2 to the return air heat extraction unit 1.

[0075] The heat pump piping connects the heat pump units in heat pump section 2. The medium flowing through the heat pump piping is referred to as the heat pump working fluid. The heat pump piping includes a heat extraction interface, a heat supply interface, and a hot water interface, which can be, for example, a tee interface. The heat extraction interface connects the heat extraction pipe to the heat pump piping and is located downstream of the internal circulation pump. The heat supply interface connects the heat pump piping to the heat supply pipe and is located downstream of the heat supply circulation pump (described later). The hot water interface connects the heat pump piping to the hot water pipe and is located downstream of the hot water circulation pump (described later).

[0076] The heating pipeline transfers the high-grade heat energy generated by the heat pump unit 2 to the user end using a heating medium (e.g., ethylene glycol solution), for applications such as building heating and mine shaft antifreeze. A heat meter is installed in the inlet pipe of the heating pipeline near the heating interface to measure the heat supplied to the user end. A heating circulation pump is installed in the return pipe of the heating pipeline near the heating interface to circulate the heating medium at the user end and return it to the heat pump unit 2. Generally, the circulation pump is located in the heat pump room. Treatment equipment, such as a comprehensive water treatment system, is also installed in the heating pipeline. The comprehensive water treatment system performs comprehensive treatment to improve water quality, protect the pipeline, and prevent equipment corrosion and scaling.

[0077] The hot water pipes transfer the high-grade heat energy generated by the heat pump unit 2 to the user end in the form of high-temperature hot water, for applications such as clothes drying, bathing, and heating in the dining area. A hot water calorimeter is installed in the inlet pipe of the hot water pipe near the heating interface to measure the heat of the hot water supplied to the user end. A thermometer and a pressure gauge are installed upstream of the calorimeter to measure the temperature and pressure of the hot water flowing from the heat pump unit 2 to the user end. A hot water circulation pump is installed in the return pipe of the hot water pipe near the hot water interface to circulate the hot water at the user end and return it to the heat pump unit 2. A thermometer and a pressure gauge are installed downstream of the hot water circulation pump to measure the temperature and pressure of the hot water returning from the user end to the heat pump unit 2.

[0078] As shown in the figure, 12 valves DF1 to DF12 are installed in the heat pump section 2 to switch the flow direction of the heat pump working fluid in the heat pump pipeline. Valves DF1, DF2, DF3, and DF4 are located near the heat extraction interface in the heat pump pipeline; valves DF5, DF6, DF7, and DF8 are located near the heating interface in the heat pump pipeline; and valves DF9, DF10, DF11, and DF12 are located near the hot water interface in the heat pump pipeline. Valves DF9 and DF10 are located between the first condenser 221 and the hot water interface, and valves DF11 and DF12 are located between the second condenser 222 and the hot water interface.

[0079] Figure 5 This is a schematic diagram illustrating the heating mode involved in this utility model. When heating is required for user heating in winter, the control unit 6 switches to the heating mode, causing the return air heat extraction unit 1 (return air heat extraction platform) and the heat storage unit 5 (solar thermal storage device) to operate as heat source equipment, while the cooling unit 4 (closed-loop cooling tower) does not operate. Valves DF1, DF3, DF6, DF8, DF9, and DF10 are opened, while valves DF2, DF4, DF5, DF7, DF11, and DF12 are closed. The first heat pump unit 21 (two dual-condition heat pump units) and the second heat pump unit 22 (total heat recovery heat pump unit) of the heat pump unit 2 enter heating mode.

[0080] A portion of the heat exchange medium (ethylene glycol solution) indirectly exchanges heat with the mine return air in the indirect-contact return air heat exchanger of the return air heat extraction section 1, while another portion of the heat exchange medium absorbs solar thermal energy in the heat storage section 5. This utilizes the heat from the mine return air and solar thermal energy to raise the temperature of the heat exchange medium. The higher the temperature of the heat exchange medium, the higher the heating efficiency of the heat pump unit in the heat pump section 2, and the lower the overall operating cost of the indirect-contact mine return air waste heat utilization system. The heated heat exchange medium becomes a high-grade heat source for heating.

[0081] In heating mode, heat pump unit 2 follows the reverse Carnot principle, allowing the heat exchange medium, as a high-grade heat source, to enter the evaporator of the first heat pump unit 21, which is connected to the user end. This provides a high-temperature heating medium for building heating or shaft antifreeze in the mine site. Additionally, in heating mode, the second condenser 222 of the second heat pump unit 22 does not operate, while the first condenser 221 operates. The high-temperature hot water produced by the first condenser 221 provides hot water for purposes such as employee bathing, clothes drying, and canteen heating. In heating mode, the return air heat extraction unit 1 and the heat storage unit 5 jointly acquire heat energy, thereby achieving multi-energy complementarity, energy saving, and system stability. Furthermore, in areas with peak-valley flat electricity pricing, peak-shaving and valley-filling measures are adopted to achieve economical and energy-saving operation, further ensuring the stability and safety of the project operation.

[0082] on the other hand, Figure 6 This is a schematic diagram illustrating the refrigeration mode involved in this utility model. When cooling is required in summer, the control unit 6 switches to refrigeration mode, causing the return air heat extraction unit 1 and the cooling unit 4 to operate as cold source devices, while the heat storage unit 5 remains inactive. Valves DF1, DF3, DF6, DF8, DF9, and DF10 are closed, while valves DF2, DF4, DF5, DF7, DF11, and DF12 are opened. The first heat pump unit 21 (two dual-condition heat pump units) and the second heat pump unit 22 (total heat recovery heat pump unit) of the heat pump unit 2 enter heat recovery mode.

[0083] A portion of the heat exchange medium indirectly exchanges heat with the mine return air in the indirect-contact return air heat exchanger of the return air heat extraction section 1, while another portion of the heat exchange medium dissipates heat in the cooling section 4. This utilizes both the mine return air and the cooling tower to lower the temperature of the heat exchange medium. The lower the temperature of the heat exchange medium, the higher the cooling efficiency of the heat pump unit in the heat pump section 2, and the lower the overall operating cost of the indirect-contact mine return air waste heat utilization system. The cooled heat exchange medium becomes a high-grade cold source.

[0084] In cooling mode, heat pump unit 2 follows the reverse Carnot principle, allowing the heat exchange medium from the high-grade cold source to enter the evaporator of the first heat pump unit 21, which is connected to the user end. This provides a low-temperature cooling medium to cool the buildings or shaft in the mine site. On the other hand, in cooling mode, the second heat pump unit 22 enters heat recovery mode. The first condenser 221 is not operating, while the second condenser 222 is operating. By setting the operating state of the second condenser 222, the condensing temperature is increased, thereby producing high-temperature hot water for employee bathing, clothes drying, and canteen heating.

[0085] Thus, in cooling mode, the temperature of the heat exchange medium is reduced by utilizing mine return air and outdoor air in the indirect-flow return air heat exchanger of the return air heat exchange section 1 and the cooling section 4, respectively. The inventors of this invention noted the problem that the mine return air volume is small and its cooling capacity as a cold source is limited; therefore, a closed-loop cooling tower was added. Consequently, even under high cooling loads, the combined operation of the return air heat exchange section 1 and the cooling section 4 in cooling mode can provide a cooling medium for the building and shaft.

[0086] Furthermore, during spring and autumn when only hot water is needed, control unit 6 switches to hot water mode, causing return air heat extraction unit 1 and heat storage unit 5 to operate, while cooling unit 4 does not operate. Valves DF1, DF3, DF6, DF8, DF9, and DF10 are opened, while valves DF2, DF4, DF5, DF7, DF11, and DF12 are closed. The first heat pump unit 21 of heat pump unit 2 does not operate, while the second heat pump unit 22 operates, causing the first condenser 221 to produce high-temperature hot water, which is then used for employee bathing, clothes drying, and canteen heating.

[0087] In summary, this utility model enables the interlocking mine return air waste heat utilization system to operate in three modes according to different seasons, thereby solving the overall heating, cooling, and hot water needs of the mine with a single system. This reduces initial investment, and the intelligent management during operation reduces personnel requirements, improves operational efficiency, lowers operating costs, and ensures the safe and stable operation of the system.

[0088] 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 system for utilizing the waste heat of return air in a mine with partition walls, characterized in that Possessing: A return air heat extraction part for heat exchange between mine return air and heat exchange medium; A heat pump part capable of realizing heating and cooling functions; A cooling part capable of lowering the temperature of the heat exchange medium when cooling is needed; A heat storage part capable of storing heat generated by solar energy and raising the temperature of the heat exchange medium when heating is needed; And A control part controlling the whole of the inter-wall mine return air waste heat utilization system, so that the heating mode and the cooling mode can be switched according to user needs, and the operating state of the cooling part and the heat storage part can be set according to the actual environment.

2. The inter-wall mine return air waste heat utilization system according to claim 1, wherein in the heating mode, the return air heat extraction part and the heat storage part operate as heat source equipment for heating, and the cooling part does not operate; in the cooling mode, the return air heat extraction part and the cooling part operate as cold source equipment for cooling, and the heat storage part does not operate.

3. The inter-wall mine return air waste heat utilization system according to claim 2, wherein the heat pump part comprises two or more first heat pump units and one or more second heat pump units, the first heat pump unit is a double-working-condition heat pump unit, which adopts double-working-condition cold and heat operation and can heat and cool, and the second heat pump unit is a full-heat-recovery heat pump unit, which can recover all heat to produce high-temperature hot water, has a first condenser and a second condenser, and the second condenser can make the condensing temperature higher than that of the first condenser by adjusting the operating state.

4. The inter-wall mine return air waste heat utilization system according to claim 3, wherein in the heating mode, part of the heat exchange medium exchanges heat with the mine return air in the return air heat extraction part and then flows to the heat pump part, another part of the heat exchange medium absorbs heat in the heat storage part and then flows to the heat pump part, and the first heat pump unit further raises the temperature of the heat exchange medium, so that the heat exchange medium becomes a high-grade heat source for heating.

5. The inter-wall mine return air waste heat utilization system according to claim 3, wherein in the cooling mode, part of the heat exchange medium exchanges heat with the mine return air in the return air heat extraction part and then flows to the heat pump part, another part of the heat exchange medium dissipates heat in the cooling part and then flows to the heat pump part, and the first heat pump unit further lowers the temperature of the heat exchange medium, so that the heat exchange medium becomes a high-grade cold source for cooling.

6. The inter-wall mine return air waste heat utilization system according to claim 3, wherein in the heating mode, the second condenser does not operate, and the first condenser operates to produce the high-temperature hot water, and in the cooling mode, the first condenser does not operate, the second condenser operates, and the condensing temperature is raised by adjusting the operating state of the second condenser, so that the high-temperature hot water is produced by the second condenser. ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. The partitioned mine return air waste heat utilization system according to claim 3, characterized in that the control unit is further capable of switching to a hot water mode. In the hot water mode, the return air heat extraction unit and the heat storage unit are operated, the cooling unit is not operated, the first heat pump unit is not operated, and the second heat pump unit is operated, and the high-temperature hot water is produced by the first condenser.

8. The partitioned mine return air waste heat utilization system according to claim 1, characterized in that it further comprises a liquid supplement unit, which is a constant-pressure water supplement device for supplementing the heat exchange medium in the partitioned mine return air waste heat utilization system.

9. The partitioned mine return air waste heat utilization system according to claim 8, characterized in that the liquid supplement unit comprises a liquid supplement tank for supplementing the heat exchange medium under constant pressure.

10. The partitioned mine return air waste heat utilization system according to claim 8, characterized in that a liquid supplement interface for supplementing the heat exchange medium of the liquid supplement unit is arranged at the suction inlet of a circulating pump for circulating the heat exchange medium, and the liquid supplement unit further comprises a liquid supplement constant-pressure pump and a safety pressure relief valve, wherein the liquid supplement constant-pressure pump is activated to increase the liquid supplement pressure when the pressure at the liquid supplement interface is too low, and the safety pressure relief valve is opened to reduce the pressure when the pressure at the liquid supplement interface is too high. ​ ​ ​ ​ ​

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