Automatic defrosting and dedusting system for mine ventilation air methane heat collector

Abstract

The utility model discloses an automatic defrosting and dedusting system for a mine ventilation air methane heat collector, which belongs to the technical field of mine ventilation air methane waste heat utilization and comprises an air inlet pressure sensor and an air outlet pressure sensor which are respectively arranged at an air inlet end and an air outlet end of the heat collector. A plurality of cleaning nozzles are arranged at the air inlet end of the heat collector and communicate with the liquid supply assembly; the heat collector is communicated with a liquid inlet pipe and a liquid outlet pipe; the liquid inlet pipe is fixedly connected with a medium liquid inlet temperature sensor, and the liquid outlet pipe is fixedly connected with a medium liquid return temperature sensor; electric valves are respectively arranged on the liquid inlet pipe and the liquid outlet pipe; when the temperature difference between the medium liquid inlet temperature sensor and the medium liquid return temperature sensor is smaller than a set value, the electric valve is closed, and when the pressure difference between the air inlet pressure sensor and the air outlet pressure sensor exceeds the set value, the liquid supply assembly is opened. The heat of mine ventilation air methane is used for defrosting, normal-temperature water is used for dedusting, extra energy investment is reduced, and use is convenient and fast.

Description

Technical Field

[0001] This utility model relates to the field of waste heat utilization technology of mine exhaust air, and in particular to an automatic defrosting and dust removal system for mine exhaust air heat exchangers. Background Technology

[0002] Coal mine safety production includes an independent underground ventilation system, which comprises the mine intake shaft and the exhaust (return) air shaft, responsible for providing air intake and return in the mine, respectively. Mine exhaust (return) air has a large volume and maintains a constant temperature and humidity year-round. Therefore, constructing an exhaust air waste heat recovery system in coal mines to extract heat from the exhaust air for the production of high-temperature hot water to heat the mine shaft and buildings or produce domestic hot water is an energy-saving technology with significant potential for widespread adoption.

[0003] In existing mine exhaust air heat recovery technologies, heat exchangers are typically used to extract low-temperature waste heat from the exhaust air. However, during the operation of the exhaust air waste heat recovery system in winter, the low-temperature circulating medium flowing inside the heat exchanger causes frost to form on its outer surface. Simultaneously, the long-term accumulation of coal ash and other dust on the surface of the heat exchanger not only reduces its heat exchange performance, affecting the operation of the entire exhaust air waste heat recovery system, but also compromises mine ventilation safety. Currently, hot water spraying or mechanical defrosting is commonly used for defrosting and dust removal of the heat exchanger. Hot water spraying defrosting has low efficiency and requires additional energy for hot water preparation, while mechanical defrosting is complex, unreliable, and prone to damage, resulting in high maintenance costs. Therefore, effective defrosting and dust removal measures for the heat exchanger must be adopted to address the aforementioned problems.

[0004] To address this, an automatic defrosting and dust removal system for mine exhaust air heat exchangers is proposed. Utility Model Content

[0005] The purpose of this utility model is to provide an automatic defrosting and dust removal system for mine exhaust air heat exchangers, aiming to solve or improve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, this utility model provides the following solution: This utility model provides an automatic defrosting and dust removal system for a mine exhaust air heat exchanger, including an inlet air pressure sensor and an outlet air pressure sensor, which are respectively installed at the air inlet and outlet ends of the heat exchanger; the air inlet end of the heat exchanger is provided with multiple cleaning nozzles, and the water sprayed from the multiple cleaning nozzles is used to flush the tube wall of the heat exchanger; the multiple cleaning nozzles are connected to a liquid supply assembly.

[0007] The heat exchanger is connected to an inlet pipe and an outlet pipe. The low-temperature medium flows into the heat exchanger through the inlet pipe, and the high-temperature medium flows out through the outlet pipe. A medium inlet temperature sensor is fixedly connected to the inlet pipe, and a medium return temperature sensor is fixedly connected to the outlet pipe. Electric valves are respectively installed on the inlet pipe and the outlet pipe.

[0008] When the temperature difference between the medium inlet temperature sensor and the medium return temperature sensor is less than a set value, the electric valve closes; when the pressure difference between the air inlet pressure sensor and the air outlet pressure sensor exceeds a set value, the liquid supply assembly opens.

[0009] Preferably, a controller is also provided, wherein the inlet air pressure sensor, the outlet air pressure sensor, the liquid supply component, the medium inlet liquid temperature sensor, the medium return liquid temperature sensor, and the electric valve are all electrically connected to the controller.

[0010] Preferably, the heat exchanger is installed on the exhaust air heat exchange chamber, and the exhaust air heat exchange chamber has multiple air outlets circumferentially opened on the side wall, with multiple heat exchangers fixedly connected to the air outlets; the bottom of the exhaust air heat exchange chamber is fixedly connected to and communicates with the top of the mine exhaust air diffusion tower.

[0011] Preferably, the liquid supply assembly includes a cleaning water tank disposed outside the exhaust air heat exchanger. A water pump is fixedly connected to the outlet of the cleaning water tank. A flow pipe is fixedly connected to the outlet of the water pump. Multiple branch pipes are fixedly connected to and connected to the flow pipe. Each branch pipe is correspondingly arranged with a multiple cleaning nozzle. The branch pipes are fixedly connected to and connected to the cleaning nozzles. A cleaning electric valve is fixedly connected to the flow pipe. The water pump and the cleaning electric valve are both electrically connected to the controller.

[0012] Preferably, a wastewater tank is provided at the bottom of the heat exchanger. The wastewater tank is fixedly connected to the inner wall of the exhaust air heat exchanger. A drain pipe is fixedly connected to and connected to the bottom of the wastewater tank. The end of the drain pipe away from the wastewater tank passes through the exhaust air heat exchanger and is connected to an external drainage ditch.

[0013] Preferably, a mine exhaust air heat pump unit is also provided, wherein the liquid inlet pipe is fixedly connected to and communicates with the liquid outlet end of the copper tube of the evaporator in the mine exhaust air heat pump unit, the liquid outlet pipe is fixedly connected to and communicates with the liquid inlet end of the copper tube of the evaporator in the mine exhaust air heat pump unit, and a heat extraction medium circulation pump is fixedly connected to the liquid outlet pipe.

[0014] Preferably, one side of the heat exchanger is located inside the exhaust air heat exchanger chamber, and the other end extends outside the exhaust air heat exchanger chamber. A baffle plate is fixedly connected to the bottom of the heat exchanger extending outside the exhaust air heat exchanger chamber, and the baffle plate guides the cleaning water to the wastewater tank.

[0015] Preferably, the baffle is inclined, and the height of the baffle near the sewage tank end is lower than the height of the other end.

[0016] This utility model discloses the following technical effects: A low-temperature medium flows into the heat exchanger through the inlet pipe. When the mine exhaust air flows through the air inlet of the heat exchanger, heat exchange occurs, and the low-temperature medium is heated. The heated medium flows out through the outlet pipe for further utilization, while the mine exhaust air, at a lower temperature, flows out from the air outlet of the heat exchanger. An inlet pressure sensor and an outlet pressure sensor respectively sense the air pressure of the mine exhaust air from the air inlet and outlet of the heat exchanger. When the pressure difference between the two increases beyond a set value, it is determined that impurities such as coal ash have accumulated on the surface of the heat exchanger. At this time, the liquid supply component is activated to supply water to the cleaning nozzles. The high-pressure cleaning water sprayed from the nozzles flushes and cleans the dust particles accumulated on the walls of the heat exchanger tubes, completing the dust removal. The medium inlet temperature sensor and the medium return temperature sensor sense the temperature of the medium inside the heat exchanger before and after heat extraction, respectively. When the temperature difference between the two is lower than the set temperature, it is determined that the heat exchanger has frosted, and the electric valve is closed to stop the current heat extraction function of the heat exchanger. The mine exhaust air continues to flow through the heat exchanger, using the heat carried by the mine exhaust air to melt the frost on the heat exchanger. This application determines the dust removal and defrosting status of the system by sensing temperature and pressure differences, uses the heat of the mine exhaust air for defrosting, and uses room temperature water for dust removal. It eliminates the need for hot spraying, reduces additional energy input, and has a simple structure and is easy to use. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] In the diagram: 1. Exhaust air diffuser tower; 2. Exhaust air heat exchange chamber; 3. Heat exchanger; 4. Cleaning water tank; 5. Water pump; 6. Cleaning electric valve; 7. Cleaning nozzle; 8. Sewage tank; 9. Drainage ditch; 10. Inlet air pressure sensor; 11. Outlet air pressure sensor; 12. Heat exchange medium circulation pump; 13. Mine exhaust air heat pump unit; 14. Medium inlet electric valve; 15. Medium return electric valve; 16. Medium inlet temperature sensor; 17. Medium return temperature sensor. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Reference Figure 1 This utility model provides an automatic defrosting and dust removal system for a mine exhaust air heat exchanger, including: an inlet air pressure sensor 10 and an outlet air pressure sensor 11, which are respectively installed at the air inlet end and the air outlet end of the heat exchanger 3; the air inlet end of the heat exchanger 3 is provided with multiple cleaning nozzles 7, and the water sprayed from the multiple cleaning nozzles 7 is used to flush the pipe wall of the heat exchanger 3; the multiple cleaning nozzles 7 are connected to the liquid supply assembly.

[0023] The heat exchanger 3 is connected to an inlet pipe and an outlet pipe. The low-temperature medium flows into the heat exchanger 3 through the inlet pipe, and the high-temperature medium flows out through the outlet pipe. A medium inlet temperature sensor 16 is fixedly connected to the inlet pipe, and a medium return temperature sensor 17 is fixedly connected to the outlet pipe. Electric valves are installed on the inlet pipe and the outlet pipe respectively.

[0024] When the temperature difference between the medium inlet temperature sensor 16 and the medium return temperature sensor 17 is less than the set value, the electric valve closes. When the pressure difference between the inlet air pressure sensor 10 and the outlet air pressure sensor 11 exceeds the set value, the liquid supply component opens.

[0025] The electric valve on the inlet pipe is the medium inlet electric valve 14, and the electric valve on the outlet pipe is the medium return electric valve 15.

[0026] The heat extractor 3, also called a heat exchanger, includes multiple heat exchange tubes arranged side by side in this embodiment. The channel between two adjacent heat exchange tubes is a channel that allows air to flow. Each tube is connected by a pipe. In use, the mine exhaust air flows through each channel of the heat extractor 3 and exchanges heat with the internal medium through the heat exchange tubes of the heat extractor 3. The temperature of the internal medium rises and flows out through the liquid outlet pipe for further utilization. Meanwhile, the low-temperature medium flows into each tube of the heat extractor 3 through the liquid inlet pipe, thereby continuously exchanging heat with the mine exhaust air. The mine exhaust air is discharged after its temperature drops after passing through the heat extractor 3 (the specifics are existing technology and will not be described in detail here).

[0027] In some optional embodiments, a controller is also provided, and the inlet air pressure sensor 10, the outlet air pressure sensor 11, the liquid supply assembly, the medium inlet liquid temperature sensor 16, the medium return liquid temperature sensor 17, and the electric valve are all electrically connected to the controller.

[0028] In this embodiment, the controller is a PLC controller. A programmable logic controller (PLC) is a digital computing and operating electronic system specifically designed for industrial applications. It uses a programmable memory to store instructions for performing logical operations, sequential control, timing, counting, and arithmetic operations. It controls various types of mechanical equipment or production processes through digital or analog inputs and outputs (specifically, it is existing technology and will not be described in detail here).

[0029] Medium inlet temperature sensor 16 and medium return temperature sensor 17 transmit the sensed temperature information to the controller, while air inlet pressure sensor 10 and air outlet pressure sensor 11 transmit the sensed air pressure information to the controller.

[0030] In some optional embodiments, the heat exchanger 3 is used to be installed on the exhaust air heat exchange chamber 2. The exhaust air heat exchange chamber 2 has multiple air outlets circumferentially opened on the side wall, and multiple heat exchangers 3 are fixedly connected to the air outlets. The bottom of the exhaust air heat exchange chamber 2 is fixedly connected to and communicates with the top of the mine exhaust air diffusion tower 1.

[0031] Mine exhaust air enters the exhaust air heat exchange chamber 2 through the mine exhaust air diffuser tower 1, and then flows out through the heat exchanger 3 to achieve heat exchange.

[0032] In some optional embodiments, the liquid supply assembly includes a cleaning water tank 4 located outside the exhaust air heating chamber 2. A water pump 5 is fixedly connected to the outlet of the cleaning water tank 4. A flow pipe is fixedly connected to the outlet end of the water pump 5. Multiple branch pipes are fixedly connected to and connected to the flow pipe. The multiple branch pipes are arranged one-to-one with multiple cleaning nozzles 7. The branch pipes are fixedly connected to and connected to the cleaning nozzles 7. A cleaning electric valve 6 is fixedly connected to the flow pipe. The water pump 5 and the cleaning electric valve 6 are both electrically connected to the controller.

[0033] When the cleaning electric valve 6 is opened, the water pump 5 is started, supplying water from the cleaning water tank 4 into multiple cleaning nozzles 7, thereby spraying high-pressure water. The multiple cleaning nozzles 7 are arranged in multiple rows in the vertical direction, with multiple nozzles in each row, so that the sprayed high-pressure water can cover the entire flow channel of the heat exchanger 3, achieving cleaning of the pipe wall.

[0034] In some alternative embodiments, a wastewater tank 8 is provided at the bottom of the heat exchanger 3. The wastewater tank 8 is fixedly connected to the inner wall of the exhaust air heat exchange chamber 2. A drain pipe is fixedly connected to and connected to the bottom of the wastewater tank 8. The end of the drain pipe away from the wastewater tank 8 passes through the exhaust air heat exchange chamber 2 and is connected to the external drainage ditch 9.

[0035] The cleaned water flows through the tube wall of the heat exchanger 3 into the sewage tank 8, and then flows into the external drainage ditch 9. The water in the drainage ditch 9 can be filtered, disinfected, and recycled.

[0036] In some optional embodiments, a mine exhaust air heat pump unit 13 is also provided, with the inlet pipe fixedly connected to and communicating with the liquid outlet end of the copper tube of the evaporator in the mine exhaust air heat pump unit 13, the outlet pipe fixedly connected to and communicating with the liquid inlet end of the copper tube of the evaporator in the mine exhaust air heat pump unit 13, and a heat extraction medium circulation pump 12 fixedly connected to the outlet pipe.

[0037] The mine exhaust air heat pump unit 13 (i.e., heat pump unit) is existing technology. A heat pump unit typically includes the following core components: a compressor (to increase the temperature and pressure of the refrigerant); a condenser (to release heat to the target environment); an evaporator (to absorb heat from a low-temperature heat source); and a throttling valve (to regulate the pressure and temperature of the refrigerant). The heat pump unit operates based on the reverse Carnot cycle principle. It absorbs heat from the external environment through a circulating working medium (such as refrigerant) in the evaporator, then the compressor increases the heat energy, and finally the condenser releases the heat to the environment requiring heating (the specifics are existing technology and will not be elaborated here).

[0038] In this embodiment, the medium heated inside the heat exchanger 3 enters the evaporator of the mine exhaust air heat pump unit 13 via the medium return electric valve 15 and the heat exchange medium circulation pump 12. The circulating working medium in the evaporator exchanges heat with the heat exchange medium. After the heat exchange medium is heated by the evaporator, its temperature decreases and it flows through the medium inlet electric valve 14 into the mine exhaust air heat exchanger 3 to exchange heat with the mine exhaust air again. After the heat exchange medium is heated, its temperature increases and it flows out again into the evaporator of the mine exhaust air heat pump unit 13. This process is repeated continuously. The entire process is powered by the heat exchange medium circulation pump 12.

[0039] In some alternative embodiments, one side of the heat exchanger 3 is located inside the exhaust air heat exchange chamber 2, and the other end extends out of the exhaust air heat exchange chamber 2. A baffle plate is fixed to the bottom of the heat exchanger 3 extending out of the exhaust air heat exchange chamber 2, and the baffle plate guides the cleaning water to the sewage tank 8.

[0040] In some alternative embodiments, the baffle is inclined, with the height of one end of the baffle near the sewage tank 8 being lower than the height of the other end.

[0041] The cleaning water of the heat exchanger 3 located outside the exhaust air heat exchange chamber 2 flows along the pipe wall to the baffle plate, and then flows along the baffle plate into the sewage tank 8.

[0042] When this utility model is in use, during the normal operation of the mine exhaust air heat pump unit 13 and the heat extraction medium circulation pump 12, when the temperature difference between the medium inlet temperature sensor 16 and the medium return temperature sensor 17 decreases or the temperature drops, exceeding the set value (adjustable), the PLC controller determines that the heat exchanger 3 has frosted. At this time, the PLC controller controls the medium inlet electric valve 14, the medium return electric valve 15 and the heat extraction medium circulation pump 12 to close, stopping the current heat extraction function of the heat exchanger 3. The mine exhaust air continues to flow through the heat exchanger 3, using the heat carried by the mine exhaust air to melt the frost on the outer surface of the heat exchanger 3. After the defrosting time set by the PLC controller is completed, the system automatically opens the medium inlet electric valve 14, the medium return electric valve 15, and the heat exchange medium circulation pump 12, restoring the heat exchange function of the current mine exhaust air heat exchanger 3. It also reads the temperature values ​​of the medium inlet temperature sensor 16 and the medium return temperature sensor 17. When the temperature difference returns to the initial state, the PLC controller determines that the mine exhaust air heat exchanger is completely defrosted, and the automatic defrosting process ends.

[0043] When the pressure difference between the inlet air pressure sensor 10 and the outlet air pressure sensor 11 increases and exceeds the set value (adjustable), the PLC controller determines that the heater 3 is clogged. At this time, the cleaning water pump 5 is automatically started and the cleaning electric valve 6 is opened to draw clean water from the cleaning water tank 4. After being pressurized, the water flows through the cleaning electric valve 6 and is finally sprayed out through the cleaning nozzle 7. The high-pressure cleaning water flushes and cleans the dust particles accumulated on the tube wall of the heater 3. The dust particles then fall off and flow into the lower sewage tank 8, and finally into the drainage ditch 9 through the drain pipe. After the cleaning time set by the PLC controller is completed, the system automatically reads the pressure values ​​of the inlet air pressure sensor 10 and the outlet air pressure sensor 11. When the pressure difference returns to the initial state, it is determined that the cleaning is complete, and the automatic dust removal process ends. The set value in the PLC controller can be adjusted according to the usage conditions, which is flexible, convenient, and highly reliable.

[0044] This system features fast defrosting speed, high dust removal efficiency, and the ability to perform defrosting and dust removal simultaneously or at different times. Furthermore, the system autonomously determines and automatically completes both defrosting and dust removal, resulting in high overall flexibility and reliability.

[0045] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 this utility model.

[0046] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A mine ventilation air methane heat exchanger automatic defrosting and dust removal system, characterized in that, It includes an inlet air pressure sensor (10) and an outlet air pressure sensor (11), which are respectively installed at the air inlet end and the air outlet end of the heat exchanger (3); the air inlet end of the heat exchanger (3) is provided with multiple cleaning nozzles (7), and the water sprayed by the multiple cleaning nozzles (7) is used to flush the pipe wall of the heat exchanger (3); the multiple cleaning nozzles (7) are connected to the liquid supply assembly. The heat exchanger (3) is connected to an inlet pipe and an outlet pipe. The low-temperature medium flows into the heat exchanger (3) through the inlet pipe, and the high-temperature medium flows out through the outlet pipe. A medium inlet temperature sensor (16) is fixedly connected to the inlet pipe, and a medium return temperature sensor (17) is fixedly connected to the outlet pipe. Electric valves are respectively installed on the inlet pipe and the outlet pipe. When the temperature difference between the medium inlet temperature sensor (16) and the medium return temperature sensor (17) is less than the set value, the electric valve is closed; when the pressure difference between the inlet air pressure sensor (10) and the outlet air pressure sensor (11) exceeds the set value, the liquid supply component is turned on. A controller is also provided, and the air inlet pressure sensor (10), the air outlet pressure sensor (11), the liquid supply component, the medium inlet liquid temperature sensor (16), the medium return liquid temperature sensor (17), and the electric valve are all electrically connected to the controller.

2. The automatic defrosting and dust removal system for mine exhaust air heat exchangers according to claim 1, characterized in that: The heat exchanger (3) is used to be installed on the exhaust air heat exchange chamber (2). The exhaust air heat exchange chamber (2) has multiple air outlets circumferentially opened on the side wall. Multiple heat exchangers (3) are fixedly connected to the air outlets. The bottom of the exhaust air heat exchange chamber (2) is fixedly connected to and communicates with the top of the mine exhaust air diffusion tower (1).

3. The automatic defrosting and dust removal system for mine exhaust air heat exchangers according to claim 2, characterized in that: The liquid supply assembly includes a cleaning water tank (4) located outside the exhaust air heat extraction chamber (2). A water pump (5) is fixedly connected to the outlet of the cleaning water tank (4). A flow pipe is fixedly connected to the outlet of the water pump (5). Multiple branch pipes are fixedly connected to and connected to the flow pipe. The multiple branch pipes are arranged one-to-one with the multiple cleaning nozzles (7). The branch pipes are fixedly connected to and connected to the cleaning nozzles (7). A cleaning electric valve (6) is fixedly connected to the flow pipe. The water pump (5) and the cleaning electric valve (6) are both electrically connected to the controller.

4. The automatic defrosting and dust removal system for mine exhaust air heat exchangers according to claim 2, characterized in that: A wastewater tank (8) is provided at the bottom of the heat exchanger (3). The wastewater tank (8) is fixedly connected to the inner wall of the exhaust air heat exchange chamber (2). A drain pipe is fixedly connected to the bottom of the wastewater tank (8) and connected to it. The end of the drain pipe away from the wastewater tank (8) passes through the exhaust air heat exchange chamber (2) and is connected to the external drainage ditch (9).

5. The automatic defrosting and dust removal system for mine exhaust air heat exchangers according to claim 1, characterized in that: A mine exhaust air heat pump unit (13) is also provided. The inlet pipe is fixedly connected to and communicates with the copper tube outlet end of the evaporator in the mine exhaust air heat pump unit (13). The outlet pipe is fixedly connected to and communicates with the copper tube inlet end of the evaporator in the mine exhaust air heat pump unit (13). A heat extraction medium circulation pump (12) is fixedly connected to the outlet pipe.

6. The automatic defrosting and dust removal system for mine exhaust air heat exchangers according to claim 4, characterized in that: One side of the heat exchanger (3) is located inside the exhaust air heat exchange chamber (2), and the other end extends out of the exhaust air heat exchange chamber (2). A baffle plate is fixed to the bottom of the heat exchanger (3) extending out of the exhaust air heat exchange chamber (2), and the baffle plate guides the cleaning water to the sewage tank (8).

7. The automatic defrosting and dust removal system for mine exhaust air heat exchangers according to claim 6, characterized in that: The baffle is inclined, and the height of the baffle near the sewage tank (8) is lower than the height of the other end.

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