A wellhead air supply device

Abstract

This invention discloses a wellhead air supply device, relating to the field of energy-saving ventilation technology in mines. The wellhead air supply device includes a heat extraction mechanism, a heat release mechanism, and a heat pump mechanism. The heat extraction mechanism includes a first flooded heat exchanger, which comprises a first outer shell and a first heat pipe. A first heat exchange medium is disposed within the first outer shell. One end of the first heat pipe extends into the first outer shell, and the other end extends into the return air duct. The heat release mechanism's heat release end extends into the fresh air duct. The heat pump mechanism is provided with a circulating heat exchange loop. The heat extraction end of the circulating heat exchange loop is heat-exchange connected to the first flooded heat extraction device, and the heat release end of the circulating heat exchange loop is heat-exchange connected to the heat release mechanism. This device can reduce heat loss during the heating of fresh air, improve the efficiency of waste heat recovery from return air, and reduce the energy consumption of the heat pump.

Description

Technical Field

[0001] This invention relates to the field of energy-saving ventilation technology in mines, and in particular to a wellhead ventilation device. Background Technology

[0002] To ensure the safety of underground workers, the air temperature below the coal mine's air intake needs to be above 2°C. Currently, most mine air supply uses a high-temperature air supply method, which involves using a heat source to produce high-temperature hot water to heat the fresh air. The heated fresh air is then mixed with outdoor fresh air and sent into the mine.

[0003] High-temperature air supply requires a heating chamber at the fresh air inlet in the mine to heat a portion of the fresh air. The heated fresh air is then discharged into the fresh air duct to mix with the fresh air outside the heating chamber. Because the temperature of the heated fresh air continuously decreases during mixing, the final mixed fresh air temperature falls between the temperatures of the two original fresh air sources. Since the mixing ratio is limited by various factors such as airflow velocity and pressure, it is often necessary to heat more fresh air or heat the incoming fresh air to a higher temperature to ensure the mixed temperature is above 2°C. Therefore, this air supply method results in significant heat loss.

[0004] Mine return air contains abundant low-temperature waste heat resources, with winter air temperatures generally around 15℃, and some mines even reaching 25℃. Currently, the main method for recovering waste heat from return air is spray-type heat pump technology. Spray-type heat pump technology requires the installation of a dedicated spray tower in the return air duct, relying on the direct contact between water spray and the return air for heat exchange. However, due to the large volume and high velocity of mine return air, heat exchange is insufficient, and a large amount of heat energy is discharged with the return air.

[0005] Because the waste heat from mine return air is at a low temperature, a higher heat source is needed to heat the fresh air to a higher temperature. Even if the waste heat from the return air is utilized, the compressor still needs to work to maintain the high temperature of the heat source. Since the temperature difference between the heat pump's outlet water and the mine's waste heat is large, this increases the workload on the compressor and its energy consumption.

[0006] To address the aforementioned issues, a wellhead air supply device needs to be developed to solve the problems of large heat loss during fresh air heating, low efficiency of waste heat recovery from return air, and high energy consumption of heat pumps. Summary of the Invention

[0007] The purpose of this invention is to provide a wellhead air supply device that can reduce heat loss during the heating of fresh air, improve the efficiency of waste heat recovery from return air, and reduce the energy consumption of heat pump operation.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] A wellhead ventilation device, wherein the mine is equipped with fresh air ducts and return air ducts, comprising:

[0010] A heat exchange mechanism, the heat exchange mechanism including a first flooded heat exchanger, the first flooded heat exchanger including a first shell and a first heat pipe, a first heat exchange medium being disposed inside the first shell, and one end of the first heat pipe extending into the first shell and the other end extending into the return air duct;

[0011] A heat-dissipating mechanism, wherein the heat-dissipating end of the heat-dissipating mechanism extends into the fresh air duct;

[0012] The heat pump mechanism has its heat-exchanging end connected to the first flooded heat exchanger and its heat-dissipating end connected to the heat-dissipating mechanism.

[0013] Preferably, the heat dissipation mechanism includes a second flooded heat exchanger, which includes a second outer shell and a second heat pipe. A second heat exchange medium is disposed inside the second outer shell, and one end of the second heat pipe extends into the second outer shell and the other end extends into the fresh air duct.

[0014] Preferably, the heat pump mechanism includes a compressor, an evaporator, a throttling valve, and a condenser, wherein the evaporator, the compressor, the condenser, and the throttling valve are connected in sequence to form a circulating heat exchange loop.

[0015] The compressor (31) is used to compress the circulating working fluid in the circulating heat exchange circuit;

[0016] The evaporator (32) and the first outer shell (12) form a first heat exchange circuit;

[0017] The condenser (33) and the second outer shell (22) form a second heat exchange circuit;

[0018] The throttle valve (34) is used to regulate the flow rate of the circulating working fluid.

[0019] Preferably, a plurality of first heat exchange fins are provided on the outer wall of the end of the first heat pipe that extends into the return air duct.

[0020] Preferably, the first heat exchange medium is an ethylene glycol solution.

[0021] Preferably, both the first heat exchange circuit and the second heat exchange circuit are equipped with circulating pumps.

[0022] Preferably, the heat exchange mechanism further includes a first temperature sensor for detecting the temperature of the first heat exchange medium.

[0023] Preferably, the heat dissipation mechanism further includes a second temperature sensor for detecting the temperature of the second heat exchange medium.

[0024] Preferably, the heat extraction mechanism further includes a return air fan, which is disposed inside the return air duct.

[0025] Preferably, the wellhead air supply device further includes a drain pipe, which is located at the bottom of the return air duct.

[0026] The beneficial effects of this invention are:

[0027] This invention provides a wellhead air supply device. In this device, the heat extraction mechanism adopts a full-liquid heat exchange structure, with heat pipes extending into the return air duct to directly contact the return air for heat absorption. At the same time, the heat is rapidly transferred to the first heat exchange medium inside the first outer shell, resulting in a large amount of heat being absorbed from the return air and reducing the loss of heat energy in the return air.

[0028] The heat dissipation mechanism's heat dissipation end extends directly into the fresh air duct to heat the fresh air, eliminating the need to preheat a portion of the fresh air before mixing it with the outdoor fresh air. This means that only the fresh air in the duct needs to be heated to above 2°C to ensure the required temperature of the fresh air supplied to the mine, significantly reducing the heat dissipation temperature of the mechanism. Compared to the uncontrollable temperature of mixed heating, the heating temperature of the fresh air by this wellhead air supply device is easily controlled, thus avoiding unnecessary heat waste.

[0029] The reduction in the heat source temperature of the heat-releasing mechanism greatly reduces the temperature difference between the heat-absorbing end and the heat-releasing end of the device, thereby reducing the workload of the compressor and saving energy. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the wellhead air supply device provided by the present invention;

[0031] Figure 2 This is a schematic diagram of the heat extraction mechanism provided by the present invention;

[0032] Figure 3 This is a schematic diagram of the heat release mechanism provided by the present invention.

[0033] 1. First flooded heat exchanger; 2. Second flooded heat exchanger; 3. Heat pump mechanism; 4. Circulation pump; 5. Return air fan; 6. Fresh air fan; 7. Drain pipe;

[0034] 11. First heat pipe; 12. First housing; 13. First temperature sensor; 21. Second heat pipe; 22. Second housing; 23. Second temperature sensor; 31. Compressor; 32. Evaporator; 33. Condenser; 34. Throttling valve;

[0035] 111, First heat exchanger plate; 211, Second heat exchanger plate. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0038] Unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and connections within two components or interactions between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0039] Unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] This embodiment provides a wellhead ventilation device. The mine is equipped with fresh air ducts and return air ducts for introducing fresh air from outside the mine and discharging return air from inside the mine. Figure 1 and Figure 2As shown, the wellhead air supply device includes a heat extraction mechanism, a heat release mechanism, and a heat pump mechanism 3. The heat extraction mechanism includes a first flooded heat exchanger 1, which comprises a first outer shell 12 and a first heat pipe 11. A first heat exchange medium is disposed inside the first outer shell 12. One end of the first heat pipe 11 extends into the outer shell, and the other end extends into the return air duct. The heat release mechanism's heat release end extends into the fresh air duct. The heat extraction end of the heat pump mechanism 3 is heat-exchange connected to the first flooded heat exchanger, and the heat release end of the heat pump mechanism 3 is heat-exchange connected to the heat release mechanism.

[0042] The heat exchange mechanism exchanges heat with the return air through one end of the first heat pipe 11, which extends into the return air duct. This causes the first working medium inside to evaporate and move towards the end extending into the first outer shell 12, releasing heat and raising the temperature of the first heat exchange medium. The first heat exchange medium releases heat at the heat-extracting end of the heat pump mechanism 3. After the heat pump mechanism 3 performs work on it, the heat level rises further, and the heat is transferred to the heat-releasing mechanism via the heat-releasing end. The heat-releasing mechanism then exchanges heat with the fresh air at its heat-releasing end, thus heating the fresh air. Since the entire heating process is controllable, it is only necessary to heat the fresh air in the fresh air duct to above 2°C to ensure that the temperature of the fresh air supplied to the mine meets the requirements.

[0043] Since the heat exchange efficiency between the heat dissipation mechanism and the fresh air directly affects the temperature of the fresh air after heating, it is necessary to improve the heat exchange efficiency as much as possible. Otherwise, most of the heat cannot be quickly released at the heat dissipation end of the heat dissipation mechanism to heat the fresh air, resulting in waste.

[0044] like Figure 3 As shown, to solve the above problems, the heat dissipation mechanism includes a second flooded heat exchanger 2. The second flooded heat exchanger 2 includes a second outer shell 22 and a second heat pipe 21. A second heat exchange medium is disposed inside the second outer shell 22. One end of the second heat pipe 21 extends into the second outer shell 22, and the other end extends into the fresh air duct. The second heat exchange medium exchanges heat with the heat dissipation end of the heat pump mechanism 3 to raise its temperature. Through direct contact, the second working fluid inside the second heat pipe 21 is heated and evaporated, moves towards the end extending into the fresh air duct, and liquefies to release heat, thereby raising the temperature of the fresh air.

[0045] To ensure sufficient heat absorption, the first flooded heat exchanger 1 needs to be equipped with multiple first heat pipes 11. At the same time, to ensure smooth return air flow, the multiple first heat pipes 11 need to be spaced out.

[0046] Similarly, the second flooded heat exchanger 2 needs to be equipped with multiple second heat pipes 21. At the same time, in order to ensure the smooth flow of fresh air, the multiple second heat pipes 21 need to be set at intervals.

[0047] Furthermore, the heat pump mechanism 3 also includes a compressor 31, an evaporator 32, a condenser 33, and a throttling valve 34. The compressor 31, evaporator 32, throttling valve 34, and condenser 33 are connected in sequence to form a circulating heat exchange loop. The compressor 31 is used to compress the circulating working fluid in the circulating heat exchange loop. The evaporator 32 and the first outer casing 12 form a first heat exchange loop, and the condenser 33 and the second outer casing 22 form a second heat exchange loop. The throttling valve 34 is used to regulate the flow rate of the circulating working fluid. The circulating working fluid can flow in the circulating heat exchange loop and can exchange heat with the first heat exchange medium in the evaporator 32 and with the second heat exchange medium in the condenser 33.

[0048] The circulating working fluid absorbs heat from the first heat exchange medium in the evaporator 32 and evaporates. As it flows through the compressor 31, it is compressed into a high-temperature gas and flows to the condenser 33, where it releases heat to heat the second heat exchange medium. During this process, the high-temperature gas liquefies and cools, releasing a large amount of heat to ensure the temperature rise of the second heat exchange medium. Simultaneously, the flow rate of the circulating working fluid can be controlled by adjusting the throttle valve 34 as needed to rationally control the temperature of the fresh air and save energy.

[0049] The circulating working fluid can be ammonia or Freon.

[0050] The characteristic of a circulating working fluid is that it is a substance that can be liquefied at room temperature or a lower temperature. It increases the heat change over a small temperature range through a reversible phase change, thereby increasing the efficiency of heat exchange.

[0051] Preferably, the throttle valve 34 can be a capillary tube.

[0052] The circulating working fluid, condensed into a liquid state, flows through the capillary tube. Since it enters from the large tube into the small tube, the flow rate is limited. Therefore, the pressure of the circulating working fluid decreases and the temperature continues to drop after it exits. This not only controls the flow rate but also further reduces the temperature of the circulating working fluid, thereby improving its heat exchange efficiency in the evaporator 32.

[0053] Since both the return air and fresh air have relatively high air speeds, heat exchange only occurs through heat pipes, which is slow and can easily lead to incomplete heat absorption in the return air and incomplete heating of the fresh air. This wastes the residual heat of the return air and prevents the fresh air temperature from meeting the requirements.

[0054] To reduce the waste of return air heat and increase the temperature of the heated fresh air, more efficient heat exchange is required. Multiple first heat exchange fins 111 are installed on the outer wall of the end of the first heat pipe 11 that extends into the return air duct, and multiple second heat exchange fins 211 are installed on the outer wall of the end of the second heat pipe 21 that extends into the fresh air duct. Utilizing multiple heat exchange fins to increase the heat exchange area significantly improves the heat exchange rate per unit time.

[0055] Preferably, the first heat exchange medium is an ethylene glycol solution.

[0056] The greater the temperature difference between the end of the first heat pipe 11 that extends into the return air duct and the end that extends into the first outer casing 12, the higher the heat exchange efficiency; and under the same conditions, the faster the heat exchange rate. To increase this temperature difference, the temperature of the first heat exchange medium needs to be lowered. However, the first heat exchange medium cannot solidify due to excessively low temperatures; therefore, a first heat exchange medium with a low freezing point needs to be found. Ethylene glycol is miscible with water in any proportion, and the freezing point of an ethylene glycol solution decreases within a certain range as the ethylene glycol content increases. Ethylene glycol solutions of different concentrations can be used as heat exchange media as needed to improve heat exchange efficiency.

[0057] Optionally, the volume concentration of the ethylene glycol solution is 20%-60%.

[0058] A 20% ethylene glycol solution has a freezing point of -10°C, which is sufficient for most applications. However, some special scenarios may require a lower freezing point. The freezing point of ethylene glycol solution reaches its limit at a 60% ethylene glycol concentration, which is -48.3°C. Increasing the concentration further will actually lower the freezing point. Therefore, the optimal ethylene glycol concentration range is 20%-60%, such as 20%, 30%, 40%, 50%, and 60%.

[0059] Understandably, the second heat exchange medium is either an ethylene glycol solution or water.

[0060] To increase the temperature difference between the end of the second heat pipe 21 that extends into the fresh air duct and the end that extends into the second outer casing 22, the second heat exchange medium needs to be heated to a higher temperature by the circulating working fluid. Since the choice of freezing point is not involved, ethylene glycol can be used. Its advantage is its low specific heat capacity, making it relatively easy to heat to a higher temperature, thus increasing the temperature difference between the two ends of the second heat pipe 21. However, for cost considerations, water can also be chosen as the second heat exchange medium.

[0061] Furthermore, a circulating pump 4 is installed on both the first heat exchange circuit and the second heat exchange circuit.

[0062] By using the circulating pump 4 to drive the flow of the first heat exchange medium and the second heat exchange medium, the flow rate of the first heat exchange medium and the second heat exchange medium can be adjusted according to the rate of heat absorption by the first heat pipe 11 and the rate of heat release by the second heat pipe 21, making the wellhead air supply device more efficient.

[0063] In order to determine whether the heat absorbed by the first heat exchange medium from the first heat pipe 11 is sufficient, the heat extraction mechanism also includes a first temperature sensor 13 for detecting the temperature of the first heat exchange medium.

[0064] Preferably, the first temperature sensor 13 is located before the first heat exchange medium flows into the evaporator 32.

[0065] To more intuitively detect whether the first heat exchange medium carries sufficient heat, its temperature is measured before it enters the evaporator 32 to release heat. If the temperature is low, the flow rate of the first heat exchange medium can be reduced using the circulating pump 4 to ensure that the heat exchange time between the first heat pipe 11 and the first heat exchange medium is extended. If the temperature is high, the flow rate of the first heat exchange medium can be increased to make the heat exchange more efficient.

[0066] In order to determine whether the heat released by the second heat exchange medium to the second heat pipe 21 is sufficient, the heat extraction mechanism also includes a second temperature sensor 23 for detecting the temperature of the second heat exchange medium.

[0067] Preferably, the second temperature sensor 23 is located before the second heat exchange medium flows into the condenser 33.

[0068] To more intuitively detect whether the second heat exchange medium has released sufficient heat, its temperature is measured before it enters the condenser 33 to absorb heat. If the temperature is high, the flow rate of the second heat exchange medium can be reduced using the circulating pump 4 to ensure that the heat exchange time between the second heat pipe 21 and the second heat exchange medium is extended. If the temperature is low, the flow rate of the second heat exchange medium can be increased to make the heat exchange more efficient.

[0069] Preferably, the wellhead air supply device further includes a return air fan 5, which is installed inside the return air duct.

[0070] The mine return air enters the heat exchange mechanism through the return air fan 5. The return air speed is controlled by the return air fan 5, which helps to adjust the speed according to the actual situation and prevents the heat exchange of the heat pipe from being affected by excessive or insufficient air speed.

[0071] Preferably, the wellhead air supply device further includes a fresh air fan 6, which is installed inside the fresh air duct.

[0072] Fresh air enters the heat dissipation mechanism through the fresh air fan 6. The airflow speed of the fresh air is controlled by the fresh air fan 6, which helps to adjust the airflow speed according to the actual situation and prevents the heat exchange of the heat pipe from being affected by excessive or insufficient airflow speed.

[0073] For example, the wellhead air supply device also includes a drain pipe 7, which is disposed at the bottom of the return air duct.

[0074] When the mine return air passes through the heat exchanger, the temperature of the return air decreases and condensate is released. The condensate is discharged through the drain pipe 7 to prevent the accumulation of condensate in the return air duct.

[0075] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A wellhead ventilation device, wherein the mine is equipped with a fresh air duct and a return air duct, characterized in that, include: The heat exchange mechanism includes a first flooded heat exchanger (1), which includes a first shell (12) and a first heat pipe (11). A first heat exchange medium is disposed inside the first shell (12), and one end of the first heat pipe (11) extends into the first shell (12) and the other end extends into the return air duct. The heat release mechanism has its heat release end extending into the fresh air duct. The heat release mechanism includes a second flooded heat exchanger (2). The second flooded heat exchanger (2) includes a second outer shell (22) and a second heat pipe (21). A second heat exchange medium is provided inside the second outer shell (22). One end of the second heat pipe (21) extends into the second outer shell (22), and the other end extends into the fresh air duct. The heat pump mechanism (3) has a heat-exchanging end connected to the first full-liquid heat exchanger and a heat-exchanging end connected to the heat-exchanging mechanism. The first flooded heat exchanger (1) is provided with a plurality of first heat pipes (11) arranged at intervals; the second flooded heat exchanger (2) is provided with a plurality of second heat pipes (21) arranged at intervals. The heat pump mechanism (3) includes a compressor (31), an evaporator (32), a throttle valve (34), and a condenser (33). The heat receiving end includes the evaporator (32), and the heat releasing end includes the condenser (33). The compressor (31), the evaporator (32), the throttle valve (34), and the condenser (33) are connected in sequence to form a circulating heat exchange circuit. The compressor (31) is used to compress the circulating working fluid in the circulating heat exchange circuit; The evaporator (32) and the first outer shell (12) form a first heat exchange circuit; The condenser (33) and the second outer casing (22) form a second heat exchange circuit; The throttle valve (34) is used to regulate the flow rate of the circulating working fluid.

2. The wellhead ventilation device according to claim 1, characterized in that, The outer wall of the end of the first heat pipe (11) that extends into the return air duct is provided with a plurality of first heat exchange plates (111).

3. The wellhead ventilation device according to claim 1, characterized in that, The first heat exchange medium is an ethylene glycol solution.

4. The wellhead ventilation device according to claim 1, characterized in that, Both the first heat exchange circuit and the second heat exchange circuit are equipped with circulating pumps (4).

5. The wellhead ventilation device according to claim 1, characterized in that, The heat exchange mechanism also includes a first temperature sensor (13) for detecting the temperature of the first heat exchange medium.

6. The wellhead ventilation device according to claim 1, characterized in that, The heat dissipation mechanism also includes a second temperature sensor (23) for detecting the temperature of the second heat exchange medium.

7. The wellhead ventilation device according to claim 1, characterized in that, The heat extraction mechanism also includes a return air fan (5), which is installed inside the return air duct.

8. The wellhead ventilation device according to claim 1, characterized in that, The wellhead air supply device also includes a drain pipe (7), which is located at the bottom of the return air duct.

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