A mine hot water system

Abstract

The application discloses a mine hot water system, which comprises an evaporator and a hot water host; the evaporator is arranged at an air supply port of a mine and an air exhaust port of the mine respectively, and the hot water host is arranged on the ground of the mine; according to the change of seasons, liquid refrigerant condensed by the hot water host is throttled and then independently sent into the independently arranged evaporator to be evaporated and exchanged with air supplied into the mine from the outside or air exhausted from the mine, and the refrigerant absorbing heat is finally used for year-round stable hot water production through condensation heat exchange, while the temperature of the air supplied into the mine from the outside through the air supply port is dynamically adjusted to meet the needs of normal operation in the mine all the year round; by using the scheme, the purpose of year-round efficient, stable and pollution-free hot water production on the basis of all-weather dynamic adjustment of the outside air to the temperature required by the normal operation of the mine can be achieved.

Description

[0001] This invention relates to the field of heating technology, and more particularly to a mine hot water system. Background Technology

[0002] To ensure the safety and comfort of miners working underground, ventilation systems are generally mandatory to ensure the fresh air needed by miners in the mine tunnels and to promptly remove harmful gases from the mine. At the same time, hot water is provided by burning coal for miners to bathe.

[0003] The ventilation involved is generally in the form of forced ventilation, which supplies air to the mine and exhausts air from the outside atmosphere. The supplied air is drawn from the outside atmosphere, while the exhaust air is discharged directly to the outside.

[0004] However, the above-mentioned ventilation methods have several drawbacks. When low-temperature air is delivered into the well in winter, the low air temperature may affect the work efficiency of the workers. When high-temperature air is delivered in summer, the high air temperature may also affect the work efficiency of the workers. Direct exhaust to the outside also results in energy loss of the constant temperature and high humidity air in the well.

[0005] The method of providing hot water by burning coal has problems such as environmental pollution and low efficiency. Summary of the Invention

[0006] To address the aforementioned problems, the mine hot water system provided by this invention utilizes a throttled refrigerant, after condensation, to absorb heat from either the fresh air supplied to the mine through the air inlet or the air discharged from the mine through the exhaust outlet, based on seasonal changes. This allows for the stable production of hot water year-round. Simultaneously, the system dynamically adjusts the temperature of the outside air supplied to the mine through the air inlet to ensure that the temperature within the mine meets normal operating requirements. The produced hot water is used for bathing by underground workers. Thus, by dynamically adjusting the outside air temperature to meet the normal operating temperature of the mine around the clock, and through a heat pump method, the system achieves efficient, stable, and pollution-free hot water production.

[0007] To achieve the above objectives, the present invention provides a mine hot water system, including an evaporator and a hot water unit; the evaporator is respectively installed at the mine's air supply outlet and mine's exhaust outlet, and the hot water unit is installed on the mine surface. The system is characterized in that, according to seasonal changes, the liquid refrigerant condensed by the hot water unit is throttled and then sent to the independently installed evaporator, where it undergoes evaporative heat exchange with the air supplied to the mine from the outside, or with the air discharged from the mine. The refrigerant that absorbs heat is ultimately used to stably produce hot water year-round through condensation heat exchange. Simultaneously, the temperature of the outside air supplied to the mine through the mine's air supply outlet is dynamically adjusted to meet the needs of normal underground operations throughout the year.

[0008] Furthermore, the evaporator is divided into a first evaporator and a second evaporator; the first evaporator is located at the air supply outlet of the mine, and the second evaporator is located at the air exhaust outlet of the mine.

[0009] The dual evaporator setup allows for adjustment of the evaporator's location according to different seasons, ensuring sufficient absorption of heat from outside air or exhaust for stable hot water production.

[0010] Furthermore, a surface cooler is also provided, which is divided into a first surface cooler and a second surface cooler; the first surface cooler is located next to the first evaporator, and the second surface cooler is located next to the second evaporator; the air inlet surface of the first surface cooler and the air outlet surface of the second surface cooler both face the outside atmosphere; the circulating water flowing into the first surface cooler is used to cool the high-temperature outside air flowing into the mine's air outlet or to heat the low-temperature outside air; the second surface cooler is used for heat exchange between the circulating water that has absorbed heat flowing out of the first surface cooler and the air that flows out of the mine's exhaust outlet and has been cooled by the second evaporator.

[0011] The dual-cooler setup serves two purposes. First, it leverages the relatively stable temperature of the circulating water. By flowing into the first cooler located at the mine's air inlet, it stabilizes the temperature of the outside air entering the mine in different seasons, preventing the air temperature from being too high or too low. Second, the circulating water exiting the first cooler after heat exchange with the outside air flowing into the mine circulates into the second cooler located at the mine's exhaust outlet. Taking advantage of the relatively stable exhaust air temperature and the fact that the exhaust air volume is greater than the incoming air volume, it exchanges heat with the exhaust air again, allowing the circulating water temperature to essentially return to its original state and be reused for heat exchange in the first cooler. This achieves full recovery of exhaust air energy and realizes energy-saving regulation.

[0012] Furthermore, the circulating water is a mixture of mine water and condensate generated during heat exchange in the first evaporator, the first surface cooler, the second evaporator, and the second surface cooler.

[0013] Recycling and using the mixture of mine water and condensate as circulating water not only achieves the goal of stabilizing the temperature of the air supplied to the mine in different seasons by taking advantage of the stable temperature of the mixed water, thus fully recovering the energy of the mixed water and achieving energy conservation, but also avoids the environmental pollution caused by direct discharge.

[0014] Furthermore, a mine water storage tank is also set up on the mine surface. The mine water storage tank is used for mixing and storing the filtered and purified mine water, as well as the condensate generated during heat exchange in the first evaporator, the first surface cooler, the second evaporator, and the second surface cooler.

[0015] By using a mine water storage tank, the mine water is filtered, purified, stored, and mixed with condensate, which can achieve the effect of providing relatively clean and temperature-stable circulating water.

[0016] Furthermore, the circulating water that has been mixed and stored in the mine water storage tank is pressurized and flows sequentially into the first surface cooler and the second surface cooler. After heat exchange, it is circulated back into the mine water storage tank for storage.

[0017] The first and second surface coolers sequentially use circulating water mixed and stored in the mine water storage tank. This allows for full utilization of the relatively stable temperature of the circulating water, effectively regulating the temperature of the air supplied to the mine from the outside. Furthermore, it recovers the energy from the exhaust ventilation to restore the temperature of the circulating water. Finally, the water is stored in the mine water storage tank, achieving a stable water supply based on the full recovery of exhaust ventilation energy.

[0018] Furthermore, the circulating water that completes the heat exchange cycle and flows into the mine water storage tank continues to mix with the newly flowing mine water and condensate. Part of the water is recycled for heat exchange in the first and second surface coolers, and part is used for replenishing the hot water unit. The excess water is treated again to meet the discharge standards before being discharged.

[0019] The continuous mixing of circulating water that has completed heat exchange with newly flowing mine water and condensate ensures the replenishment of absorbed energy and maintains stable water temperature, thereby achieving a stable heat exchange effect.

[0020] Further, the hot water unit includes a housing, a compressor, a liquid receiver, a gas-liquid separator, a shell-and-tube condenser, and an expansion valve; the compressor, liquid receiver, gas-liquid separator, shell-and-tube condenser, and expansion valve are disposed within the housing, and the compressor, liquid receiver, gas-liquid separator, and shell-and-tube condenser are fixed on the base of the housing; the exhaust pipe of the compressor is connected to the inlet pipe of the shell-and-tube condenser, the liquid outlet pipe of the shell-and-tube condenser is connected to the inlet of the liquid receiver, the outlet of the liquid receiver is connected to the inlet of the expansion valve, the pipe connected to the outlet of the expansion valve is divided into two paths, which are respectively connected to the inlet pipes of the first evaporator and the second evaporator through solenoid valves; the return pipe of the first evaporator is connected to the outflowing first check valve, the return pipe of the second evaporator is connected to the outflowing second check valve, the outlets of the first check valve and the second check valve merge and are connected to the inlet of the gas-liquid separator, and the outlet of the gas-liquid separator is connected to the return pipe of the compressor.

[0021] The hot water unit is simple in structure and has good operational reliability. It can flexibly select evaporators located at the air supply outlet and the mine exhaust outlet respectively for evaporative heat exchange according to climate changes, thereby achieving energy-saving operation while reliably and stably producing hot water.

[0022] Furthermore, a heat recovery device is also provided, comprising an outer casing and a heat recovery unit. The outer casing has a square three-dimensional structure, with a fresh air inlet and a fresh air outlet, as well as an exhaust air inlet and an exhaust air outlet, respectively, on its four sides. The fresh air inlet and the fresh air outlet, and the exhaust air inlet and the exhaust air outlet are arranged facing each other. The heat recovery unit is inserted diagonally along the outer casing, forming a crossflow path between the outside air flowing between the fresh air inlet and the fresh air outlet and the exhaust air flowing between the exhaust air inlet and the exhaust air outlet. The heat recovery unit then recovers the energy of the exhaust air.

[0023] Auxiliary fresh air ducts are installed on the air ducts flowing into the mine section from the mine's air supply outlet. One end of the inflow section of the auxiliary fresh air duct is connected to the air duct located in front of the mine section, and the other end is connected to the fresh air inlet of the heat recovery device. One end of the outflow section of the auxiliary fresh air duct is connected to the fresh air outlet of the heat recovery device, and the other end is connected to the air duct behind the mine section. By adjusting the air valves installed in the inlet and outlet sections of the auxiliary fresh air ducts and the air ducts flowing into the mine section, outside air can flow through the auxiliary fresh air ducts, recover heat, and then continue to flow into the mine, or flow directly into the mine from the mine's air supply outlet.

[0024] An auxiliary exhaust duct is installed on the outermost duct of the mine's exhaust outlet. The inflow section of the auxiliary exhaust duct is connected at one end to the outermost duct of the exhaust outlet and at the other end to the exhaust inlet of the heat recovery device. The outflow section of the auxiliary exhaust duct is connected at one end to the exhaust outlet of the heat recovery device and at the other end to the outside atmosphere. By adjusting the air valve installed at the inlet of the auxiliary exhaust duct and the air valve installed on the outermost duct of the mine's exhaust outlet, the exhaust air can be discharged directly to the outside after heat recovery through the auxiliary exhaust duct, or directly discharged to the outside from the mine's exhaust outlet.

[0025] The heat recovery device ensures that, under extreme weather conditions, the energy of the air discharged from the mine is recovered, and the temperature of the air sent into the mine from the outside is further regulated, thereby achieving the effect of energy saving while ensuring the temperature required for underground operations.

[0026] The present invention also provides a method for producing hot water, using the above-mentioned mine hot water system, comprising the following steps:

[0027] Step S1: Start the mine water hot water system control switch, close the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator, and open the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator; at the same time, supply circulating water to the first and second surface coolers, and after a delay of 60 seconds, the hot water unit starts to produce hot water;

[0028] Step S2: After the mine hot water system has been running for 15 to 30 minutes and is in a stable operating state, it will automatically adjust its operation according to the temperature changes of the outside air throughout the year.

[0029] When the outside air temperature is ≥45℃, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is opened, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is closed. The outside air is first cooled by the first surface cooler, and then the liquid refrigerant condensed during the hot water production process is throttled and supplied to the first evaporator for evaporation and heat exchange, thus cooling the air a second time. The refrigerant in the first evaporator absorbs the heat from the air cooled by the first evaporator and is used to produce hot water. The air cooled a second time flows in the auxiliary fresh air duct and is cooled by the heat recovery device. After absorbing the cold air from the exhaust, the air is cooled a third time and finally flows into the mine, maintaining the temperature of the air supplied to the mine at 25-30℃.

[0030] When the outside air temperature is between 30 and 45°C, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is opened, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is closed. The outside air is first cooled by the first surface cooler, and then the liquid refrigerant condensed during the hot water process in the main hot water unit is throttled and supplied to the first evaporator for evaporation and heat exchange, resulting in secondary cooling. The refrigerant in the first evaporator absorbs the heat from the initially cooled air and is used to produce hot water. The air cooled by the second cooling flows directly into the mine, maintaining the air temperature supplied to the mine at 20 to 25°C.

[0031] When the outside air temperature is between 10 and 30°C, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is closed, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is opened; the refrigerant in the second evaporator absorbs the heat from the air discharged from the mine and is used to produce hot water; the outside air is cooled by the first surface cooler and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 15 to 25°C;

[0032] When the outside air temperature is between 0 and 10°C, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is closed, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is opened; the refrigerant in the second evaporator absorbs the heat from the air discharged from the mine and is used to produce hot water; the outside air is heated by the first surface cooler and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 15 to 20°C;

[0033] When the outside air temperature is between -20°C and 0°C, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is closed, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is opened; the refrigerant in the second evaporator absorbs the heat from the air discharged from the mine and is used to produce hot water; the outside air is heated by the first surface cooler and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 10°C to 15°C;

[0034] When the outside air temperature is ≤-20℃, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is closed, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is opened; the refrigerant in the second evaporator absorbs the heat from the air discharged from the mine and is used to produce hot water; after the outside air is initially heated by the first surface cooler, the heated air flows in the auxiliary fresh air duct, and undergoes heat recovery through the heat recovery device, absorbing the heat from the exhaust air to complete the secondary heating, and finally flows into the mine, maintaining the air temperature supplied to the mine at 10~15℃;

[0035] Step S3: Turn off the control switch of the mine water hot water system, stop supplying circulating water to the first and second surface coolers, close the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator, or the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator, delay for 30 to 60 seconds, the hot water unit stops running, and after another delay of 60 to 90 seconds, stop supplying water to the shell and tube condenser.

[0036] The mine hot water system employing this technical solution utilizes a throttled refrigerant, condensed, to absorb heat from either the fresh air supplied to the mine through the air inlet or the air discharged from the mine outlet, based on seasonal changes, to provide stable hot water production year-round. Simultaneously, it dynamically adjusts the temperature of the outside air supplied to the mine through the air inlet to ensure the mine temperature meets normal operating requirements. The produced hot water is used for bathing by underground workers, thus achieving at least the following:

[0037] 1. It can dynamically adjust the outside air temperature to meet the normal operating temperature of the mine around the clock;

[0038] 2. By absorbing heat from the supply or exhaust air through a heat pump, the system achieves efficient, stable, and environmentally friendly hot water production, significantly reducing energy consumption. Attached Figure Description

[0039] Figure 1 This is a schematic diagram illustrating the working principle of the system of the present invention.

[0040] Figure 2 This is a schematic diagram illustrating the working principle of the system of the present invention under extreme climatic conditions.

[0041] Figure 3This is a flowchart of the method for producing hot water according to the present invention.

[0042] In the diagram, 1-Air outlet, 11-Blower, 12-First surface cooler, 13-First evaporator, 14-First drip tray, 15-First condensate drain pipe, 16-Circulating water return pipe, 17-Circulating water supply pipe, 2-Hot water unit, 21-Shell, 211-Base, 22-Gas-liquid separator, 221-First check valve, 222-Second check valve, 23-Compressor, 24-Expansion valve, 241-First solenoid valve, 242-Second solenoid valve, 25-Liquid receiver, 26-Shell-tube condenser, 261-Hot water inlet pipe, 262-Hot water outlet pipe, 3-Exhaust outlet, 31-Second evaporator, 32-Second surface cooler, 321 - Circulating water outflow pipe, 33-Exhaust fan, 34-Second water receiving tray, 341-Second condensate drain pipe, 35-Mine water storage tank, 36-Water quality processor, 37-Mine water inflow pipe, 38-Circulating water pump, 39-Drainage pipe, 4-Ground surface, 5-Underground, 6-Heat recovery device, 61-Heat recovery unit, 62-Exhaust air inlet, 621-Exhaust air duct A, 622-First exhaust air valve, 623-Second exhaust air valve, 63-Fresh air outlet, 631-Fresh air duct A, 632-First fresh air valve, 64-Exhaust air outlet, 641-Exhaust air duct B, 65-Fresh air inlet, 651-Fresh air duct B, 652-Second fresh air valve. Implementation

[0043] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] like Figure 1 As shown, a mine hot water system includes an evaporator and a hot water unit 2. The evaporators are respectively installed at the mine air inlet 1 and the mine exhaust outlet 3. The hot water unit 2 is installed on the mine ground 4. According to seasonal changes, the liquid refrigerant condensed by the hot water unit 2 is sent to the independently installed evaporator after throttling. It conducts evaporative heat exchange with the outside air supplied to the mine or with the air discharged from the mine. The refrigerant that absorbs heat is finally used to stably produce hot water all year round through condensation heat exchange. At the same time, it regulates the temperature of the outside air supplied to the mine through the mine air inlet 1 to ensure that the temperature in the mine meets the needs of normal operation.

[0045] The outside air supplied to the mine is fresh air. Considering that the exhaust air may contain harmful components, it is no longer used as return air, but is instead completely discharged into the outside atmosphere.

[0046] To ensure the normal and healthy operation of workers underground, the mine is equipped with air supply outlet 1 and air exhaust outlet 3, which are directly connected to the underground tunnels through ventilation ducts extending deep underground 5.

[0047] Fresh air from the outside is delivered into the underground tunnel through the mine's air supply outlet 1, providing breathing space for the workers and ensuring their health. Meanwhile, harmful gases such as carbon dioxide in the underground tunnel are discharged into the outside atmosphere through the mine's exhaust outlet 3, ensuring that the air quality in the underground tunnel meets the requirements for safe working conditions.

[0048] To ensure the efficiency of air supply and exhaust, a blower 11 is installed at the inlet of air supply outlet 1. Fresh air from the outside is pre-circulated by the blower 11 and sent into the underground tunnel through air supply outlet 1. At the same time, an exhaust fan 33 is installed at the outlet of exhaust outlet 3. The exhaust fan 33 forces exhaust, so that harmful waste gas in the underground tunnel is discharged through exhaust outlet 3.

[0049] In actual use, to avoid damage caused by harmful gases during underground operations, the exhaust air volume is greater than the fresh air volume supplied from the outside. This ensures that the generated harmful gases can be discharged in a timely manner, preventing them from accumulating underground and harming the health of underground workers, as well as preventing potential hazards such as fires and explosions, thereby ensuring the safety of underground operations.

[0050] In order to achieve the heat exchange needs of the mine's air supply outlet 1 for supplying fresh air throughout the year and the mine's exhaust outlet 3 for discharging harmful waste gas from the mine's tunnels, thereby saving energy and adjusting the temperature of the supplied fresh air, preferably, the evaporator is divided into a first evaporator 13 and a second evaporator 31.

[0051] The first evaporator 13 is located at the mine air inlet 1, and the second evaporator 31 is located at the mine exhaust outlet 3.

[0052] By adjusting the location of the evaporator according to different seasons, it is possible to fully absorb heat from the outside air or exhaust air and stabilize the production of hot water.

[0053] In order to realize the utilization of the energy contained in the mine groundwater and evaporator condensate throughout the year, and to achieve the purpose of saving energy and adjusting the temperature of the fresh air to be supplied, preferably, a surface cooler is also provided, which is divided into a first surface cooler 12 and a second surface cooler 32.

[0054] The first surface cooler 12 is located next to the first evaporator 13, and the second surface cooler 32 is located next to the second evaporator 31.

[0055] The air inlet surface of the first surface cooler 12 and the air outlet surface of the second surface cooler 32 both face the outside atmosphere.

[0056] The first surface cooler 12 is located between the blower 11 and the first evaporator 13, and the second surface cooler 32 is located between the second evaporator 31 and the exhaust fan 33.

[0057] Of course, the air inlet surface of the first surface cooler 12 and the air outlet surface of the second surface cooler 32 can also be set in other suitable positions to ensure that the air inlet surface of the first surface cooler 12 and the air outlet surface of the second surface cooler 32 both face the outside atmosphere. For example, the first surface cooler 12 can also be set outside the blower 11 and the second surface cooler 32 can be set outside the exhaust fan 33, etc., in suitable positions that meet the requirements.

[0058] To recover condensate and reduce pollution, a first water collection tray 14 is installed at the bottom of the first surface cooler 12 and the first evaporator 13, and a second water collection tray 34 is installed at the bottom of the second surface cooler 32 and the second evaporator 31.

[0059] The condensate collected in the first drip tray 14 is discharged through the first condensate drain pipe 15, and the condensate collected in the second drip tray 34 is discharged through the second condensate drain pipe 341.

[0060] The circulating water flowing into the first surface cooler 12 is used to cool down the high-temperature outside air flowing into the mine air outlet 1 or to heat up the low-temperature outside air.

[0061] The second surface cooler 32 is used for heat exchange between circulating water that flows out of the first surface cooler 12 and absorbs heat, and air that flows out of the mine exhaust vent 3 and is cooled by the second evaporator 31; or for heat exchange between circulating water that releases heat and air that flows out of the mine exhaust vent 3 and is heated by the second evaporator 31.

[0062] The circulating water used is a mixture of mine water and condensate produced during heat exchange with the first surface cooler 12, the first evaporator 13, the second evaporator 31 and the second surface cooler 32.

[0063] Mine water, including groundwater and cleaning water, has a relatively stable temperature, which is above zero degrees Celsius and generally remains in the range of 10 to 15 degrees Celsius. The temperature of the condensate produced during heat exchange in the first surface cooler 12, the first evaporator 13, the second evaporator 31, and the second surface cooler 32 is also around 15 degrees Celsius.

[0064] In actual use, the mixing ratio of mine water in the mixed water is significantly greater than that of condensate water, and the mixing temperature mainly fluctuates slightly around the mine water temperature.

[0065] When the outside air temperature flowing into the mine air outlet 1 is high in summer, the mixed water flows into the heat exchange tube of the first surface cooler 12 and exchanges heat with the high-temperature air flowing over the outer surface of the first surface cooler 12. After the high-temperature air temperature drops, it is finally sent into the mine to maintain the appropriate temperature required for underground operations. This effectively avoids the extra energy consumption for cooling down the mine and the possible fires caused by leakage, thus fully improving the utilization rate of mixed water energy.

[0066] The circulating water that absorbs heat flows back to the heat exchange tubes of the second surface cooler 32, where it exchanges heat with the exhaust air that flows out of the mine's exhaust port 3 and is cooled by the second evaporator 31. It absorbs the coldness of the cooled air, and after the temperature drops and returns to its original state, it is finally circulated to provide cooling for the first surface cooler 12.

[0067] In extreme high-temperature conditions, if the air temperature cooled by the first surface cooler 12 is insufficient, the high-temperature outside air flowing through the first surface cooler 12 can be further cooled by the evaporation heat exchange of the first evaporator 13. At this time, the second evaporator 31 is no longer used. Only the circulating water that undergoes secondary heat exchange with the air flowing out of the mine exhaust vent 3 through the second surface cooler 32 is cooled down and then mixed with new mixed water to further reduce and stabilize the temperature. This water is then circulated to provide cooling for the first surface cooler 12.

[0068] Because of the cooling effect of the first surface cooler 12, the ambient air temperature that exchanges heat with the first evaporator 13 will not be very high, thereby reducing the evaporation temperature of the refrigerant that exchanges heat in the first surface cooler 12. This avoids problems such as overload operation of the hot water unit 2, thus achieving the goal of stable and reliable operation of the hot water unit 2.

[0069] The underground air discharged from the mine exhaust vent 3 has relatively stable humidity and its temperature generally remains within the range of 15-26℃ throughout the year. Therefore, the stable temperature can be fully utilized to stabilize the production of hot water through the evaporation heat exchange of the second evaporator 31, or to achieve heat recovery and temperature regulation, thereby realizing the recovery and utilization of energy.

[0070] When the outside air temperature flowing into the mine air supply outlet 1 is low in winter, the mixed water flows into the heat exchange tube of the first surface cooler 12 and exchanges heat with the low-temperature air flowing over the outer surface of the first surface cooler 12. After the temperature of the low-temperature air rises, it is finally sent into the mine to maintain the appropriate temperature required for underground operations. This effectively avoids the extra energy consumption caused by heating up the mine, as well as the possible fires caused by leakage, and fully improves the utilization rate of mixed water energy.

[0071] After the temperature of the circulating water that releases heat decreases, it flows back to the heat exchange tube of the second surface cooler 32 and exchanges heat with the exhaust air that flows out from the mine exhaust port 3 and is cooled by the second evaporator 31. After absorbing the heat of the cooled air, the temperature rises back to its original state and finally circulates to provide heat exchange for the first surface cooler 12.

[0072] Because the circulating water flows continuously in the heat exchange tubes of the first surface cooler 12 and the second surface cooler 32, there is no problem of icing. Moreover, the circulating water is constantly mixed with new water, and the energy source continuously provides circulating water at a stable temperature to the first surface cooler 12 for heat exchange, which is used to raise the temperature of the outside air flowing into the mine air outlet 1, thus ensuring that the required underground mine operating temperature is met.

[0073] In extreme low-temperature conditions, if the air temperature raised by the first surface cooler 12 is insufficient, a secondary heating method can be adopted by heat recovery. First, the heat recovery device is used to recover heat from the air discharged from the mine exhaust port 3, and then the heat is released by the heat recovery device to the air heated by the first surface cooler 12 to further increase the air temperature. Alternatively, the heat recovery device can be used to directly release heat to the outside air flowing into the mine air supply port 1 to increase the temperature, and then the air can be heated by the first surface cooler 12 before being sent into the mine.

[0074] It can be seen that by adopting the technical solution of this invention, not only can the energy of mixed water be effectively recovered, but also the energy of mine ventilation can be recovered, which greatly saves energy.

[0075] The dual-cooler setup utilizes the relatively stable temperature of the circulating water. Firstly, the water flowing into the first cooler at the mine's air inlet helps regulate the temperature of the incoming air in different seasons, preventing variations in air temperature. Secondly, the circulating water exiting the first cooler after heat exchange with the incoming air flows into the second cooler at the mine's exhaust outlet. Taking advantage of the stable exhaust air temperature and the larger exhaust volume than the incoming air, the water undergoes further heat exchange with the exhaust air, restoring the circulating water temperature to near its original state. This allows the water to be reused for heat exchange in the first cooler, thus fully recovering exhaust energy and achieving energy-saving regulation.

[0076] In order to fully recover and utilize the energy of the discharged mine water and condensate, and reduce the pollution caused by direct discharge, preferably, the circulating water is a mixture of mine water and condensate generated during heat exchange with the first evaporator 13, the first surface cooler 12, the second evaporator 31, and the second surface cooler 32.

[0077] When fresh air flows over the outer surfaces of the first evaporator 13 and the first surface cooler 12, the condensate produced by the heat exchange between the fresh air and the first evaporator 13 and the first surface cooler 12, resulting in a temperature decrease, and when exhaust air flows over the outer surfaces of the second evaporator 31 and the second surface cooler 32, the condensate produced by the heat exchange between the exhaust air and the second evaporator 31 and the second surface cooler 32, resulting in a temperature decrease, both have the characteristic of stable temperature. Currently, the commonly used method is direct discharge, which not only causes a lot of environmental pollution, but also causes energy loss.

[0078] Similarly, mine water has a stable temperature, and direct discharge would cause environmental pollution and energy loss.

[0079] Therefore, by comprehensively utilizing the mixture of mine water and condensate as circulating water, we can not only take advantage of the stable temperature of the mixture to achieve the goal of stably regulating the temperature of the air sent into the mine in different seasons, thus fully recovering the energy of the mixture and saving energy, but also avoid the environmental pollution caused by direct discharge.

[0080] To ensure a stable supply of circulating water with sufficient quantity and clean quality, and to enable the first surface cooler 12 to stably regulate the temperature of the air supplied to the mine from the outside in different seasons, preferably, a mine water storage tank 35 is also provided on the mine surface 4. The mine water storage tank 35 is used for mixing and storing the filtered and purified mine water, as well as the condensate generated during the heat exchange of the first evaporator 13, the first surface cooler 12, the second evaporator 31, and the second surface cooler 32.

[0081] The mine water storage tank 35 can be configured as a closed storage tank with a concrete structure covered with insulation material on the outer surface, or other closed tanks covered with insulation material on the outer surface.

[0082] The mine water discharged from the mine undergoes preliminary filtration and purification before flowing into the mine water storage tank 35 through the mine water inlet pipe 37, where it settles.

[0083] The filtration method used is a filter to remove impurities such as gravel, and the purification method can be chemical purification or other means.

[0084] Meanwhile, the exhaust gas flowing through the outer surface of the second evaporator 31 and the second surface cooler 32, and the condensate generated during heat exchange are discharged into the mine water storage tank 35 through the second condensate drain pipe 341 and mixed with the mine water.

[0085] The fresh air flowing through the outer surface of the first evaporator 13 and the first surface cooler 12 generates condensate during heat exchange. The condensate is discharged through the first condensate drain pipe 15 and mixed with the circulating water returning in the circulating water return pipe 16. Finally, it flows through the circulating water outlet pipe 321 into the mine water storage tank 35 and mixes with the mine water.

[0086] By using a mine water storage tank, the mine water is filtered, purified, stored, and mixed with condensate to provide a stable supply of relatively clean and temperature-stable circulating water for use in external fresh air and exhaust heat exchange.

[0087] To achieve a stable temperature for the first surface cooler 12 to continuously regulate the temperature of the air supplied to the mine from the outside in different seasons and meet the normal production needs of underground operations, preferably, the circulating water that has been mixed and stored in the mine water storage tank 35 is pressurized and flows sequentially into the first surface cooler 12 and the second surface cooler 13, and after heat exchange, it is circulated back into the mine water storage tank 35 for storage.

[0088] In actual use, the circulating water stored in the mine water storage tank 35 is treated by the water quality processor 36, and then pressurized by the circulating water pump 38 before flowing from the circulating water supply pipe 17 into the heat exchange tubes of the surface cooler 12.

[0089] The system cools and regulates the fresh air with higher outside temperatures in summer and heats and regulates the fresh air with lower outside temperatures in winter. The circulating water that has completed the heat exchange flows out of the first surface cooler 12 and into the circulating water return pipe 16. After merging with the condensate discharged from the first condensate drain pipe 15, it flows into the second surface cooler 32 through the circulating water return pipe 16 to continue exchanging heat with the exhaust air. At this time, the circulating water with a higher temperature in summer absorbs the cold air from the exhaust air and lowers its temperature, while the circulating water with a lower temperature in winter absorbs the heat from the exhaust air and raises its temperature.

[0090] After completing the heat exchange with the exhaust air, the water flows out of the surface cooler 32 and then circulates into the mine water storage tank 35 through the circulating water outlet pipe 321.

[0091] The aforementioned circulating water heat exchange system can make full use of the relatively stable temperature of the circulating water to stabilize and regulate the temperature of the air supplied to the mine from the outside. On this basis, it can recover the energy of the exhaust air to restore the temperature of the circulating water, thereby achieving the goal of energy saving.

[0092] To further stabilize the supply of circulating water to the first surface cooler 12, thereby achieving the goal of stabilizing the temperature of the air sent into the mine from the outside in different seasons, preferably, the circulating water that has completed the heat exchange circulation and flows into the mine water storage tank 35 is continuously mixed with the newly flowing mine water and condensate. Part of the water is circulated for heat exchange in the first surface cooler 12 and the second surface cooler 32, part of it is used for water replenishment in the hot water unit 2, and the excess is treated again to meet the discharge standards before being discharged.

[0093] The circulating water flowing into the second surface cooler 32 exchanges heat with the exhaust air. Although this can basically restore the temperature of the circulating water, fluctuations in the water supply parameters to the first surface cooler 12 may occur due to factors such as changes in the circulating water flow rate and exhaust air volume. This directly affects the stability of regulating the temperature of the air supplied to the mine from the outside in different seasons. Therefore, the circulating water is stored in the mine water storage tank 35 after heat exchange, and mixed with the newly flowing mine water and condensate. Generally, since the amount of newly flowing mine water is larger than the amount of circulating water used for circulation, mixing can effectively compensate for the insufficient heat exchange with the exhaust air, and ultimately achieve more precise control of the circulating water temperature, ensuring the stable regulation of the temperature of the air supplied to the mine from the outside in different seasons.

[0094] In addition, the mixed circulating water is also used to replenish the hot water unit 2, which also achieves the purpose of saving water. The excess mixed water flows out through the drain pipe 39, is treated again, and is discharged after meeting the discharge standards, which also reduces environmental pollution.

[0095] By continuously mixing the circulating water that has completed heat exchange with the newly flowing mine water and condensate, the replenishment of absorbed energy can be ensured, and the water temperature can be kept stable, thereby achieving stable heat exchange and reducing water waste and environmental pollution.

[0096] To achieve efficient, reliable, and stable hot water production, it is preferable to use a hot water unit 2 with the following configuration.

[0097] The hot water unit 2 includes a casing 21, a gas-liquid separator 22, a compressor 23, an expansion valve 24, a liquid receiver 25, and a shell-and-tube condenser 26.

[0098] The gas-liquid separator 22, the first check valve 221, the second check valve 222, the compressor 23, the expansion valve 24, the first solenoid valve 241, the second solenoid valve 242, the liquid receiver 25, and the shell-and-tube condenser 26 are disposed inside the housing 21, and the gas-liquid separator 22, the compressor 23, the liquid receiver 25, and the shell-and-tube condenser 26 are fixed on the base 211 of the housing 21.

[0099] The discharge pipe of compressor 23 is connected to the inlet pipe of shell and tube condenser 26. The liquid outlet pipe of shell and tube condenser 26 is connected to the inlet of liquid receiver 25. The outlet of liquid receiver 25 is connected to the inlet of expansion valve 24. The pipe connected to the outlet of expansion valve 24 is divided into two paths, which are connected to the liquid inlet pipe of first evaporator 13 through first solenoid valve 241 and to the liquid inlet pipe of second evaporator 31 through second solenoid valve 242.

[0100] The return pipe of the first evaporator 13 is connected to the outflowing first check valve 221, and the return pipe of the second evaporator 31 is connected to the outflowing second check valve 222; the outlets of the first check valve 221 and the second check valve 222 merge and are connected to the inlet of the gas-liquid separator 22, and the outlet of the gas-liquid separator 22 is connected to the return pipe of the compressor 23.

[0101] The hot water production process is as follows:

[0102] The high-temperature, high-pressure gaseous refrigerant compressed by the compressor 23 flows into the heat exchange tubes of the shell-and-tube condenser 26 through the exhaust pipe. It then exchanges heat with the low-temperature water flowing in from the hot water inlet pipe 261. After absorbing heat, the temperature of the low-temperature water rises and it flows out from the hot water outlet pipe 262 into external equipment to provide hot water bathing and other services for the workers in the well.

[0103] Hot water inlet pipe 261 and hot water outlet pipe 262 are both located at the top of the shell-and-tube condenser 26 and are connected to the outer shell of the shell-and-tube condenser 26.

[0104] After condensation, the refrigerant becomes a high-pressure liquid. After flowing out of the liquid outlet pipe of the shell-and-tube condenser 26, it flows into the storage tank 25 through the inlet. The liquid refrigerant flowing out of the storage tank 25 passes through the expansion valve 24 and then flows into the first evaporator 13 through the first solenoid valve 241. It then exchanges heat with the outside fresh air and absorbs the heat of the outside fresh air to produce hot water. At the same time, the cooled outside fresh air is used to regulate the ambient temperature of the downhole operation. Alternatively, it flows into the second evaporator 31 through the second solenoid valve 242 and exchanges heat with the exhaust air and absorbs the heat of the exhaust air to produce hot water.

[0105] The refrigerant that completes evaporation and heat exchange in the first evaporator 13 flows out of the first evaporator 13 through the first one-way valve 221, or the refrigerant that completes evaporation and heat exchange in the second evaporator 31 flows out of the second evaporator 31 through the second one-way valve 222.

[0106] After passing through the connecting pipeline of the first one-way valve 221 and the second one-way valve 222, it flows into the gas-liquid separator 22, and after being separated by the gas-liquid separator 22, it flows into the compressor 23 from the return gas pipe of the compressor 23, and circulates to compress and produce hot water.

[0107] The shell-and-tube condenser 26 can be replaced by other suitable heat exchangers, such as coaxial heat exchangers, high-efficiency tanks, etc.

[0108] By absorbing heat from fresh air or exhaust air, the hot water unit 2 can produce hot water around the clock. At the same time, the elimination of the four-way reversing valve greatly simplifies the system piping and control, significantly improving the reliability of equipment operation.

[0109] As for the problem of evaporator frost that may occur during operation in winter, it can be solved by switching the evaporator. In winter, the second evaporator 31 is generally used, and the temperature of the exhaust air is stable above 10℃ all year round, so the frost problem is almost non-existent. If the frost problem occurs, it can be switched to the first evaporator 13 for a short time. The temperature of the exhaust air can be used to defrost the second evaporator 31 in a short time, and then it can be switched back to the second evaporator 31.

[0110] When switching to the first evaporator 13, the outside fresh air temperature may drop for a short time. However, this can be compensated by using the heat recovery device 6 to recover heat and raise the temperature, thus ensuring the stability of the temperature of the outside fresh air flowing into the well.

[0111] Since the defrosting process does not employ a four-way reversing valve, it will not affect the temperature of the hot water, thus ensuring a stable supply of hot water throughout the year.

[0112] Of course, in situations where heating and cooling are required, a four-way reversing valve can be installed to provide cold water for cooling in summer and hot water for heating in winter, while also providing hot water for bathing.

[0113] The hot water unit 2 provided by this invention has a simple structure and good operational reliability. It can flexibly select and use evaporators set at the air supply outlet and the mine exhaust outlet respectively for evaporative heat exchange according to climate change, thereby achieving the goal of energy-saving operation while reliably and stably producing hot water.

[0114] To further conserve energy and ensure a stable supply of fresh air at the required temperature to the mine under extreme weather conditions, a heat recovery device 6 is preferably also installed; the mine hot water system using the heat recovery device 6 is described in [reference needed]. Figure 2 Schematic diagram.

[0115] The heat recovery device 6 includes an outer casing and a heat recovery unit 61. The outer casing has a square three-dimensional structure, and fresh air inlet 65 and fresh air outlet 63, exhaust air inlet 62 and exhaust air outlet 64 are respectively provided on the four sides of the outer casing.

[0116] The fresh air inlet 65 and the fresh air outlet 63, as well as the exhaust air inlet 62 and the exhaust air outlet 64, are arranged facing each other. The heat recovery unit 61 is inserted diagonally along the outer casing, forming a cross flow path between the outside air flowing between the fresh air inlet 62 and the fresh air outlet 63 and the exhaust air flowing between the exhaust air inlet 62 and the exhaust air outlet 64. The heat recovery unit 61 completes the recovery of energy from the exhaust air.

[0117] Auxiliary fresh air ducts are installed on the air ducts flowing into the mine section of the air supply outlet 1. The auxiliary fresh air ducts are divided into two sections: fresh air duct A631 and fresh air duct B651.

[0118] The fresh air duct B651 is located in the inflow section of the auxiliary fresh air duct. One end of the fresh air duct B651 is connected to the duct located in front of the mine inflow section, that is, it is connected to the duct located after the first surface cooler 12 and the first evaporator 13 and before the mine inflow section. The other end of the fresh air duct B651 is connected to the fresh air inlet 65 of the heat recovery device 6.

[0119] Fresh air duct A631 is located in the outflow section of the auxiliary fresh air duct. One end is connected to the fresh air outlet 63 of the heat recovery device, and the other end of fresh air duct A631 is connected to the air duct behind the mine section.

[0120] The inlet of the fresh air duct B651, which constitutes the auxiliary fresh air duct, is located in front of the outlet of the fresh air duct A631. The auxiliary fresh air duct is equivalent to forming an auxiliary flow channel on the duct connected to the air supply outlet 1, which is used for heat recovery and temperature regulation of the outside fresh air.

[0121] Driven by the blower 11, the outside air flows sequentially through the first surface cooler 12 and the first evaporator 13, and then flows along the fresh air duct formed by the fresh air duct B651, the heat recovery unit 61, and the fresh air duct A631. The outside air that has completed the exhaust heat recovery finally flows back to the duct connected to the air outlet 1 and is sent into the well.

[0122] By adjusting the air valves installed in the auxiliary fresh air ducts at the inlet and outlet of the mine, outside air can flow through the auxiliary fresh air ducts, recover heat, and then continue to flow into the mine, or flow directly into the mine from the mine's air outlet.

[0123] Specifically, the fresh air valve is configured such that the first fresh air valve 632 is located at the connection point between the fresh air duct A631 and the duct flowing into the mine section. When the first fresh air valve 632 is closed, it can cut off the air flowing out of the fresh air duct A631, while simultaneously opening the duct flowing into the mine from the air outlet 1; conversely, it opens the air flowing out of the fresh air duct A631, while simultaneously closing the duct flowing into the mine from the air outlet 1.

[0124] The second fresh air valve 652 is located at the point where the air supply duct connects to the fresh air duct B651. When the second fresh air valve 652 is opened, fresh air from the outside can flow into the fresh air duct B651. When it is closed, the flow of fresh air from the outside into the fresh air duct B651 is cut off.

[0125] The fresh air valve should be adjusted as follows:

[0126] If it is necessary for fresh air from the outside to flow into the auxiliary fresh air duct for heat recovery and heat exchange, the first fresh air valve 632 and the second fresh air valve 652 are opened at the same time. The duct connected to the air outlet 1 is closed by the opened first fresh air valve 632. At this time, the fresh air from the outside that has exchanged heat with the first surface cooler 12 and the first evaporator 13 flows into the mine after the heat recovery unit 61 recovers the energy of the exhaust air.

[0127] If the energy of the exhaust air does not need to be recovered through the heat recovery unit 61, the first fresh air valve 632 and the second fresh air valve 652 are closed, and the outside fresh air flows directly into the mine after heat exchange through the first surface cooler 12 and the first evaporator 13.

[0128] For the installation of the auxiliary fresh air duct, an auxiliary exhaust duct is installed on the outermost duct of the mine's exhaust outlet 3. The auxiliary exhaust duct is divided into two sections: exhaust duct A621 and exhaust duct B641.

[0129] The exhaust duct A621 is located in the inflow section of the auxiliary exhaust duct. One end of the exhaust duct A621 is connected to the duct located on the outermost side of the exhaust port 3, and the other end of the exhaust duct A621 is connected to the exhaust inlet 62 of the heat recovery device 61.

[0130] The exhaust duct B641 is located in the outflow section of the auxiliary exhaust duct. One end of the exhaust duct B641 is connected to the exhaust outlet 64 of the heat recovery device, and the other end is connected to the outside atmosphere.

[0131] The inlet of the exhaust duct A621, which constitutes the auxiliary exhaust duct, is located on the outermost side of the second evaporator 31 and the second surface cooler 32, and is connected to the duct of the exhaust port 3. The auxiliary exhaust duct is equivalent to forming an auxiliary flow channel on the duct connected to the exhaust port 3, which is used to recover the energy of the air discharged from the mine.

[0132] Driven by the exhaust fan 33, the exhaust air in the mine is forced to flow through the second evaporator 31 and the second surface cooler 32, and then flows along the exhaust air channel formed by the exhaust air duct A621, the heat recovery unit 61 and the exhaust air duct B641, and finally the exhaust air that has completed the heat recovery is discharged to the outside atmosphere.

[0133] By adjusting the air valve installed at the inlet of the auxiliary exhaust duct and the air valve installed on the outermost duct of the mine exhaust outlet 3, the exhaust air can be discharged directly to the outside after heat recovery from the flow in the auxiliary exhaust duct, or directly discharged to the outside from the mine exhaust outlet 3.

[0134] Specifically, the exhaust valve is configured such that the first exhaust valve 622 is located at the connection point between the exhaust duct A621 and the outermost duct of the exhaust port 3. When the first exhaust valve 622 is closed, the exhaust air flowing in from the first exhaust valve 622 can be cut off; when the first exhaust valve 622 is open, the exhaust air flows in from the first exhaust valve 622.

[0135] The second exhaust valve 623 is installed on the duct that connects to the outermost part of the exhaust port 3. When the second exhaust valve 623 is opened, the exhaust air is directly discharged to the outside atmosphere, and the first exhaust valve 622 is closed. When the second exhaust valve 623 is closed, the exhaust air flows into the exhaust duct A621 through the open first exhaust valve 622, and after heat recovery by the heat recovery unit 61, it is directly discharged to the outside atmosphere through the exhaust duct B641.

[0136] By opening the first exhaust valve 622 and closing the second exhaust valve 623, exhaust air can flow through the auxiliary exhaust duct and be discharged directly to the outside after heat recovery; while by closing the first exhaust valve 632 and opening the second exhaust valve 623, exhaust air can be discharged directly from the mine's exhaust port 3 to the outside.

[0137] In actual use, if heat recovery between fresh air and exhaust air is to be achieved, the relevant fresh air and exhaust air valves are adjusted to allow fresh air to flow in the fresh air duct and exhaust air to flow in the exhaust air duct. The heat exchanger 61 completes the energy exchange between fresh air and exhaust air, thus achieving energy recovery.

[0138] If heat recovery between fresh air and exhaust air is not required, the auxiliary fresh air duct and auxiliary exhaust air duct are closed. Fresh air from the outside is treated and then directly sent into the mine shaft, while exhaust air is discharged directly into the outside atmosphere after heat recovery.

[0139] As can be seen from the above, the installation of the heat recovery device ensures that, under extreme climatic conditions, the energy of the air discharged from the mine is recovered, and the temperature of the air sent into the mine from the outside is further regulated, thereby achieving the goal of ensuring the temperature required for underground operations while realizing energy conservation.

[0140] Figure 2 Compared to Figure 1 The difference lies in the addition of a heat recovery device 6 and its connected air ducts and matching air valves. By recovering the heat of the exhaust air, it provides an additional means of temperature regulation for the outside fresh air under extreme climatic conditions. Thus, based on further energy recovery of the exhaust air, it can achieve more precise and stable regulation of the outside fresh air temperature flowing into the mine.

[0141] for Figure 1 Its applications can be used in areas where the ambient temperature is not very high or very low, such as regions where the annual temperature is between 0 and 30°C. Figure 2Its application is in regions where summer temperatures are high and winter temperatures are low, such as northern regions.

[0142] Of course, it can also be used in all regions. Figure 2 The technical solution aims to achieve further energy saving and precise adjustment of the outside fresh air temperature.

[0143] This invention also provides a method for producing hot water, using the aforementioned mine hot water system to produce hot water to ensure a stable supply year-round. Simultaneously, the temperature of the outside air supplied to the mine through the mine's air inlet 1 is adjusted to ensure the mine's temperature meets the requirements for normal operation. (See also...) Figure 3 The flowchart shows the specific steps:

[0144] Step S1: Start the mine water hot water system control switch, close the first solenoid valve 241 that controls the flow of throttling liquid refrigerant to the first evaporator 13, and open the second solenoid valve 242 that controls the flow of throttling liquid refrigerant to the second evaporator 31; at the same time, supply circulating water to the first surface cooler 12 and the second surface cooler 32. After a delay of 60 seconds, the hot water unit 2 starts to operate and produce hot water.

[0145] Step S2: After the mine hot water system has been running for 15-30 minutes and is in a stable operating state, it will automatically adjust its operation based on the annual changes in outside air temperature.

[0146] When the outside air temperature is ≥45℃, the first solenoid valve 241, which controls the flow of throttling liquid refrigerant to the first evaporator 13, is opened, and the second solenoid valve 242, which controls the flow of throttling liquid refrigerant to the second evaporator 31, is closed. The outside air is first cooled by the first surface cooler 12, and then the liquid refrigerant condensed during the hot water production process of the hot water unit 1 is throttled by the expansion valve 24 and supplied to the first evaporator 13 for evaporation and heat exchange, thus cooling the air that has been initially cooled. The refrigerant in the first evaporator 13 absorbs the heat from the initially cooled air and is used to produce hot water. The air that has been cooled a second time flows in the auxiliary fresh air duct and is heat recovered by the heat recovery device 6. After absorbing the cold energy of the exhaust air, it completes the third cooling and finally flows into the mine, maintaining the air temperature supplied to the mine at 25-30℃.

[0147] When the outside air temperature is ≥45℃, it is in an extremely hot summer environment. Given the high outside air temperature, in order to ensure a suitable temperature for the outside air supplied to the mine, a three-stage temperature regulation method is adopted for the fresh air flowing in from the air outlet 1. The first stage is to initially cool the air through the first surface cooler 12, reducing the temperature to below 35℃. Then, the air undergoes evaporation and heat exchange through the throttled refrigerant in the first evaporator 13, achieving a second stage of cooling, reducing the temperature to below 25℃. Finally, the exhaust air is cooled through the heat recovery device 6, which recovers energy. This three-stage cooling method precisely regulates the air temperature, keeping it stable within the range of 25-30℃.

[0148] The heat recovery process is as follows: exhaust air flows through heat recovery unit 61, and heat recovery unit 61 absorbs the cold energy of the exhaust air. When the high-temperature outside fresh air crosses through heat recovery unit 61, it absorbs the cold energy of heat recovery unit 61, and the temperature decreases, thereby achieving three-stage cooling.

[0149] Specifically, regarding the methods of temperature regulation, the first-stage regulation of the first surface cooler 12 can be achieved by adjusting the circulating water flow rate, velocity, and air volume. For regulating the ambient air in extremely high temperatures, the first surface cooler 12 can be configured with a multi-row structure, such as a 6-8 row structure, or multiple first surface coolers 12 can be connected in parallel to the circulating water pipes. For the second-stage regulation of the first evaporator 13, since the regulation is achieved through refrigerant evaporation heat exchange, it can be achieved by adjusting the refrigerant flow rate and air volume. Adjusting the refrigerant flow rate is generally achieved by using a variable frequency air conditioning system in the hot water unit 2 to achieve more precise second-stage temperature regulation, which can meet the needs of occasions with large and frequent changes in ambient temperature. The third-stage regulation, which involves heat recovery through the heat recovery device 6, can be achieved by adjusting the air volume to achieve further precise and stable regulation of the air under second-stage temperature regulation.

[0150] The air volume adjusted above shall not be lower than the minimum air volume required for underground operations in the mine. In actual use, the blower 11 and the exhaust fan 33 can be variable frequency fans. Of course, they can also be fixed frequency fans that meet the requirements, or multiple fans can be set up.

[0151] When the outside air temperature is between 30 and 45°C, the first solenoid valve 241, which controls the flow of throttling liquid refrigerant to the first evaporator 13, is opened, and the second solenoid valve 242, which controls the flow of throttling liquid refrigerant to the second evaporator, is closed. The outside air is first cooled by the first surface cooler 12, and then cooled a second time by the liquid refrigerant condensed during the hot water production process of the hot water unit 2. The refrigerant is throttled and supplied to the first evaporator 13 for evaporation and heat exchange. The refrigerant in the first evaporator 13 absorbs the heat from the initially cooled air and is used to produce hot water. The air cooled a second time flows directly into the mine, maintaining the air temperature supplied to the mine at 20 to 25°C.

[0152] When the outside air temperature is between 30 and 45°C, it is in a typical summer environment. Given that the outside air temperature is not extremely high, in order to ensure a suitable temperature for the outside air supplied to the mine, a two-stage temperature regulation method is adopted for the fresh air flowing in from the air outlet 1. The first stage is to initially cool the air through the first surface cooler 12, reducing the temperature to below 30°C. Then, the refrigerant in the first evaporator 13 is throttled for evaporation and heat exchange, achieving a second stage of cooling, reducing the temperature to below 25°C, so that the air temperature is stabilized within the range of 20 to 25°C.

[0153] For environments of 30–45℃, the temperature is not very high compared to high temperatures of ≥45℃. Therefore, a two-stage cooling method is sufficient to meet the usage requirements. In this case, a three-stage cooling method is not required. The adjustment methods are the same as above and will not be repeated. Of course, the three-stage adjustment methods mentioned above can also be used.

[0154] When the outside air temperature is between 10 and 30°C, the first solenoid valve 241, which controls the flow of throttling liquid refrigerant to the first evaporator 13, is closed, and the second solenoid valve 242, which controls the flow of throttling liquid refrigerant to the second evaporator 31, is opened. The refrigerant in the second evaporator 31 absorbs the heat from the air discharged from the mine and is used to produce hot water. The outside air is cooled by the first surface cooler 12 and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 15 to 25°C.

[0155] For an environment of 10-30℃, which is basically in spring and autumn, the outside air temperature is suitable. Therefore, only one-stage cooling is required. That is, after the first-stage cooling treatment of the first surface cooler 12, the temperature is reduced to below 20℃, which can meet the requirements of underground operation. At the same time, considering the possible fluctuations in outside air temperature in different seasons and factors such as heat exchange efficiency, the first evaporator 13 is not used to absorb heat to produce hot water. Instead, the refrigerant in the second evaporator 31 absorbs the heat of the air discharged from the mine to continuously and stably produce hot water.

[0156] For lower ambient air temperatures, such as close to 10°C, which are similar to the temperature of circulating water, the air temperature supplied to the mine can be adjusted by reducing the circulating water flow rate to maintain the air temperature between 15°C and 25°C. If the temperature does not meet the requirements, the heat recovery device 6 can be restarted to readjust the temperature, or the first evaporator 13 can be added at the same time for cooling adjustment to ensure the required temperature.

[0157] For environments ranging from 10 to 30°C, the specific adjustment methods are the same as above and will not be repeated here.

[0158] When the outside air temperature is between 0 and 10°C, the first solenoid valve 241, which controls the flow of throttling liquid refrigerant to the first evaporator 13, is closed, and the second solenoid valve 242, which controls the flow of throttling liquid refrigerant to the second evaporator 31, is opened. The refrigerant in the second evaporator 31 absorbs the heat from the air discharged from the mine and is used to produce hot water. The outside air is heated by the first surface cooler 12 and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 15 to 20°C.

[0159] For an environment of 0-10℃, which is basically the transition season between winter and spring and autumn and winter, the outside air temperature is low, but not much different from the temperature required for underground mine. Therefore, the air temperature sent into the mine can be maintained at 15-20℃ by the first stage heating method of the first surface cooler 12. At the same time, based on the instability of the outside air temperature during seasonal transitions, the refrigerant in the second evaporator 31 absorbs the heat of the air discharged from the mine and uses it to make hot water.

[0160] Of course, the outside air temperature can also be adjusted by activating the heat recovery device 6.

[0161] Its working principle is similar to that of an environment with a temperature range of 10-30℃. The difference is that it heats up in an environment with a temperature range of 0-10℃, while it cools down in an environment with a temperature range of 0-30℃. This is because the temperature of the circulating water is relatively stable throughout the year, basically maintained within the range of 10-15℃. It can achieve the purpose of cooling when the outside air temperature is lower than 10-30℃, and can achieve the purpose of heating when the outside air temperature is higher than 0-10℃, which greatly improves the energy utilization efficiency of the circulating water.

[0162] For environments ranging from 0 to 10°C, the specific adjustment methods are the same as above, such as adjusting the circulating water flow rate, etc., which will not be elaborated further.

[0163] When the outside air temperature is between -20°C and 0°C, the first solenoid valve 241, which controls the flow of throttling liquid refrigerant to the first evaporator 13, is closed, and the second solenoid valve 242, which controls the flow of throttling liquid refrigerant to the second evaporator 31, is opened. The refrigerant in the second evaporator 31 absorbs the heat from the air discharged from the mine and is used to produce hot water. The outside air is heated by the first surface cooler 12 and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 10°C to 15°C.

[0164] In an environment of -20 to 0°C, which is essentially winter, the outside air temperature is significantly low. At this time, the air temperature supplied to the mine is maintained at 10 to 15°C by heating the air through the first surface cooler 12. Meanwhile, since the outside air temperature is below zero, the refrigerant in the second evaporator 31 absorbs the heat from the air discharged from the mine to achieve stable hot water production, thereby improving the efficiency of absorbing external heat in a low-temperature environment.

[0165] By using circulating water at around 10-15℃ and heat exchange through the first surface cooler 12, the ambient low-temperature air is heated. The heating methods are the same as above, mainly by increasing the circulating water flow rate, increasing the number of rows of the first surface cooler 12, and reducing the air volume of the ambient air, so as to maintain the air temperature sent into the mine at 10-15℃.

[0166] If the reduced outside air volume reaches the lower limit of the required minimum air volume, and the air temperature delivered to the mine still does not meet the requirements, it is advisable to use the heat recovery device 6 for heat recovery and heating, in addition to using the first surface cooler 12 to raise the temperature.

[0167] When the outside air temperature is ≤-20℃, the first solenoid valve 241 controlling the flow of throttling liquid refrigerant to the first evaporator 13 is closed, and the second solenoid valve 242 controlling the flow of throttling liquid refrigerant to the second evaporator 31 is opened; the refrigerant in the second evaporator 31 absorbs the heat from the air discharged from the mine and is used to produce hot water; after the outside air is initially heated by the first surface cooler 12, the heated air flows in the auxiliary fresh air duct and is heated by the heat recovery device 6, absorbing the heat from the exhaust air to complete the secondary heating, and finally flows into the mine, maintaining the air temperature supplied to the mine at 10~15℃;

[0168] For environments with temperatures ≤-20℃, which are located in the harsh winter season in the north, the environment is extremely cold. Given the extremely low outside air temperature, in order to ensure a suitable temperature for the outside air supplied to the mine, a two-stage temperature regulation method is adopted for the fresh air flowing in from the air outlet 1. The first stage is to initially raise the temperature through the first surface cooler 12, raising the temperature above 0℃. Then, the exhaust air is heated in a second stage by recovering energy through the heat recovery device 6, so as to more accurately regulate the air temperature and stabilize it within the range of 10-15℃.

[0169] The specific adjustment methods adopted are the same as those for adjusting the corresponding equipment in the above-mentioned extremely hot environments, and will not be repeated here.

[0170] To prevent icing from occurring in the first surface cooler 12 under extremely cold conditions, the fin offset of the first surface cooler 12 is 9-16 mm, and the fin offset of the first evaporator 13 is 6-12 mm. The wide fin spacing helps to reduce frost formation on the surface of the finned heat exchanger.

[0171] To ensure stable hot water production and improve heat exchange efficiency under extreme cold conditions, a stable heat exchange method between the second evaporator 31 and the exhaust air is adopted to produce hot water. The first evaporator 13 is generally not used. It is only used briefly when defrosting is required on the surface of the second evaporator 31. After defrosting, the second evaporator 31 is immediately switched to be used.

[0172] Since the exhaust temperature remains stable above zero degrees Celsius year-round, the second evaporator 31 generally does not experience frost formation. A standard offset of 1.6–2.0 mm can be used, which can greatly save copper materials and reduce manufacturing costs.

[0173] Step S3: When stopping hot water production, turn off the control switch of the mine water hot water system, stop supplying circulating water to the first surface cooler 12 and the second surface cooler 32, close the first solenoid valve 241 that controls the flow of throttling liquid refrigerant to the first evaporator 13 and the second solenoid valve 242 that controls the flow of throttling liquid refrigerant to the second evaporator 31, delay for 30 to 60 seconds, the hot water main unit 2 stops running, and then stops supplying water to the shell and tube condenser 26 for another 60 to 90 seconds.

[0174] The hot water unit 2 is stopped after a delay of 30 to 60 seconds. The purpose is to draw back the refrigerant from the first evaporator 13 or the second evaporator 31 to avoid equipment damage that may occur when starting under load again. After the hot water unit 2 stops running, the water supply to the shell-and-tube condenser 26 is stopped 60 to 90 seconds later. The purpose is to fully complete the condensation and heat exchange of the gaseous refrigerant in the shell-and-tube condenser 26, and to avoid problems such as heat exchange tube damage that may occur due to the refrigerant continuing to exchange heat due to water shortage.

[0175] The above-mentioned division of the outside air temperature range is a preferred example. Of course, it can also be divided into other suitable temperature ranges according to the needs of use, so as to provide outside air that meets the temperature requirements for underground operations in the mine while ensuring stable hot water production throughout the year.

[0176] The evaporator and surface cooler of the technical solution of the present invention are finned heat exchangers.

[0177] Mines include coal mines, or other types of mines.

[0178] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A mine hot water system, comprising an evaporator and a hot water unit; the evaporator is respectively installed at the mine's air supply outlet and mine's air exhaust outlet, and the hot water unit is installed on the mine surface, characterized in that, Depending on seasonal changes, the liquid refrigerant condensed by the hot water unit is throttled and sent to the independently set evaporator, where it exchanges heat with the air supplied to the mine from the outside or with the air discharged from the mine. The refrigerant that absorbs heat is finally used to stably produce hot water all year round through condensation heat exchange. At the same time, the temperature of the outside air supplied to the mine through the mine's air outlet is dynamically adjusted to meet the needs of normal underground operations throughout the year. The evaporator is divided into a first evaporator and a second evaporator; the first evaporator is installed at the air supply outlet of the mine, and the second evaporator is installed at the air exhaust outlet of the mine. A surface cooler is also provided, which is divided into a first surface cooler and a second surface cooler; the first surface cooler is located next to the first evaporator, and the second surface cooler is located next to the second evaporator; the air inlet surface of the first surface cooler and the air outlet surface of the second surface cooler both face the outside atmosphere; the circulating water flowing into the first surface cooler is used to cool the high-temperature outside air flowing into the mine's air outlet or to heat the low-temperature outside air; the second surface cooler is used for heat exchange between the circulating water that has absorbed heat flowing out of the first surface cooler and the air that flows out of the mine's exhaust outlet and has been cooled by the second evaporator. The circulating water is a mixture of mine water and condensate produced during heat exchange with the first evaporator, the first surface cooler, the second evaporator, and the second surface cooler.

2. The mine hot water system as described in claim 1, characterized in that, A mine water storage tank is also set up on the mine surface. The mine water storage tank is used for mixing and storing the filtered and purified mine water, as well as the condensate produced during heat exchange in the first evaporator, the first surface cooler, the second evaporator, and the second surface cooler.

3. The mine hot water system as described in claim 2, characterized in that, The circulating water that has been mixed and stored in the mine water storage tank is pressurized and flows sequentially into the first surface cooler and the second surface cooler. After heat exchange, it is circulated back into the mine water storage tank for storage.

4. The mine hot water system as described in claim 3, characterized in that, The circulating water that completes the heat exchange cycle and flows into the mine water storage tank continues to mix with the newly flowing mine water and condensate. Part of the water is recycled for heat exchange in the first and second surface coolers, and part is used for makeup water for the hot water unit. The excess water is treated again to meet the discharge standards before being discharged.

5. The mine hot water system as described in claim 4, characterized in that, The hot water unit includes a housing, a compressor, a liquid receiver, a gas-liquid separator, a shell-and-tube condenser, and an expansion valve. The compressor, liquid receiver, gas-liquid separator, shell-and-tube condenser, and expansion valve are housed within the housing and fixed to a base on the housing. The compressor's exhaust pipe connects to the shell-and-tube condenser's inlet pipe, the shell-and-tube condenser's outlet pipe connects to the liquid receiver's inlet, and the liquid receiver's outlet connects to the expansion valve's inlet. The pipe connecting to the expansion valve's outlet is divided into two paths, each connected to the inlet pipes of the first and second evaporators via solenoid valves. The first evaporator's return pipe connects to the first outflowing check valve, and the second evaporator's return pipe connects to the second outflowing check valve. The outlets of the first and second check valves merge and connect to the inlet of the gas-liquid separator. The gas-liquid separator's outlet connects to the compressor's return pipe.

6. The mine hot water system as described in claim 5, characterized in that, A heat recovery device is also provided, which includes an outer shell and a heat recovery unit. The outer shell has a square three-dimensional structure, and fresh air inlet and fresh air outlet, exhaust air inlet and exhaust air outlet are respectively provided on the four sides of the outer shell. The fresh air inlet and fresh air outlet, as well as the exhaust air inlet and exhaust air outlet, are arranged facing each other. The heat recovery unit is inserted diagonally along the outer shell, forming a cross flow path between the outside air flowing between the fresh air inlet and fresh air outlet and the exhaust air flowing between the exhaust air inlet and exhaust air outlet. The heat recovery unit completes the recovery of energy from the exhaust air. Auxiliary fresh air ducts are installed on the air ducts flowing into the mine section from the mine's air supply outlet. One end of the inflow section of the auxiliary fresh air duct is connected to the air duct located in front of the mine section, and the other end is connected to the fresh air inlet of the heat recovery device. One end of the outflow section of the auxiliary fresh air duct is connected to the fresh air outlet of the heat recovery device, and the other end is connected to the air duct behind the mine section. By adjusting the air valves installed in the inlet and outlet sections of the auxiliary fresh air ducts and the air ducts flowing into the mine section, outside air can flow through the auxiliary fresh air ducts, recover heat, and then continue to flow into the mine, or flow directly into the mine from the mine's air supply outlet. An auxiliary exhaust duct is installed on the outermost duct of the mine's exhaust outlet. The inflow section of the auxiliary exhaust duct is connected at one end to the outermost duct of the exhaust outlet and at the other end to the exhaust inlet of the heat recovery device. The outflow section of the auxiliary exhaust duct is connected at one end to the exhaust outlet of the heat recovery device and at the other end to the outside atmosphere. By adjusting the air valve installed at the inlet of the auxiliary exhaust duct and the air valve installed on the outermost duct of the mine's exhaust outlet, the exhaust air can be discharged directly to the outside after heat recovery through the auxiliary exhaust duct, or directly discharged to the outside from the mine's exhaust outlet.

7. A method for producing hot water, characterized in that, The steps for producing hot water using the mine hot water system according to any one of claims 1 to 6 are as follows: Step S1: Start the mine water hot water system control switch, close the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator, and open the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator; at the same time, supply circulating water to the first and second surface coolers, and after a delay of 60 seconds, the hot water unit starts to produce hot water; Step S2: After the mine hot water system has been running for 15-30 minutes and is in a stable operating state, it will automatically adjust its operation based on the annual changes in outside air temperature. When the outside air temperature is ≥45℃, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is opened, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is closed. The outside air is first cooled by the first surface cooler, and then the liquid refrigerant condensed during the hot water production process is throttled and supplied to the first evaporator for evaporation and heat exchange, thus cooling the air a second time. The refrigerant in the first evaporator absorbs the heat from the air cooled by the first evaporator and is used to produce hot water. The air cooled a second time flows in the auxiliary fresh air duct and is cooled by the heat recovery device. After absorbing the cold air from the exhaust, the air is cooled a third time and finally flows into the mine, maintaining the temperature of the air supplied to the mine at 25-30℃. When the outside air temperature is between 30 and 45°C, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is opened, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is closed. The outside air is first cooled by the first surface cooler, and then the liquid refrigerant condensed during the hot water process in the main hot water unit is throttled and supplied to the first evaporator for evaporation and heat exchange, resulting in secondary cooling. The refrigerant in the first evaporator absorbs the heat from the initially cooled air and is used to produce hot water. The air cooled by the second cooling flows directly into the mine, maintaining the air temperature supplied to the mine at 20 to 25°C. When the outside air temperature is between 10 and 30°C, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is closed, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is opened; the refrigerant in the second evaporator absorbs the heat from the air discharged from the mine and is used to produce hot water; the outside air is cooled by the first surface cooler and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 15 to 25°C; When the outside air temperature is between 0 and 10°C, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is closed, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is opened; the refrigerant in the second evaporator absorbs the heat from the air discharged from the mine and is used to produce hot water; the outside air is heated by the first surface cooler and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 15 to 20°C; When the outside air temperature is between -20°C and 0°C, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is closed, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is opened; the refrigerant in the second evaporator absorbs the heat from the air discharged from the mine and is used to produce hot water; the outside air is heated by the first surface cooler and flows directly into the mine, maintaining the temperature of the air supplied to the mine at 10°C to 15°C; When the outside air temperature is ≤-20℃, the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator is closed, and the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator is opened; the refrigerant in the second evaporator absorbs the heat from the air discharged from the mine and is used to produce hot water; after the outside air is initially heated by the first surface cooler, the heated air flows in the auxiliary fresh air duct, and undergoes heat recovery through the heat recovery device, absorbing the heat from the exhaust air to complete the secondary heating, and finally flows into the mine, maintaining the air temperature supplied to the mine at 10~15℃; Step S3: When stopping hot water production, close the control switch of the mine water hot water system, stop supplying circulating water to the first and second surface coolers, close the solenoid valve controlling the flow of throttling liquid refrigerant to the first evaporator, or the solenoid valve controlling the flow of throttling liquid refrigerant to the second evaporator, delay for 30 to 60 seconds, the hot water unit stops running, and after another delay of 60 to 90 seconds, stop supplying water to the shell and tube condenser.

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