Flue gas waste heat recovery device for thermal power plant

Abstract

The utility model relates to a thermal power plant flue gas waste heat recovery device which comprises a spraying mechanism and a water collecting tank which are arranged in a chimney, the bottom of the water collecting tank in the chimney is communicated with the input end of a dirt separator through a drainage pipeline, the output end of the dirt separator is fixedly connected with a booster pump, and the output end of the booster pump is communicated with the input end of the heating source side of a plate heat exchanger. The output end of the heating source side of the plate heat exchanger is communicated with the input end of the boiler air inlet heating mechanism, the output end of the boiler air inlet heating mechanism is communicated with the spraying mechanism in the chimney, the output end and the input end of the heat source side of the plate heat exchanger are communicated with the input end and the output end of the heat pump respectively, and the heating end of the heat pump is connected with a pipe network. The flue gas waste heat utilization device has the advantages that a worker can conveniently utilize flue gas waste heat to heat circulating water of a pipe network, the flue gas temperature can be lowered, and meanwhile the heat supply temperature of inlet air of the boiler can be increased.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, specifically to a waste heat recovery device for flue gas from a thermal power plant. Background Technology

[0002] In industries such as power, steel, chemical and building materials, industrial boilers are key equipment for energy conversion. Their core function is to convert the chemical energy in fuel into the heat energy required for production. However, they continuously generate a large amount of flue gas during operation, so they usually need to be equipped with special flue gas treatment devices.

[0003] Traditional flue gas treatment devices typically focus only on controlling pollutants such as desulfurization, denitrification, and dust removal. However, the large amount of sensible heat and latent heat of water vapor carried in the flue gas is often not effectively utilized. Boiler exhaust temperatures are usually 150°C (or even higher), and the temperature entering the chimney is also 70°C. Direct emission will result in a large amount of heat waste. At the same time, the flue gas forms a "white smoke" phenomenon due to the sudden drop in temperature during the emission process, which can easily cause visual and thermal pollution. Utility Model Content

[0004] This invention addresses the shortcomings of existing technologies by providing a waste heat recovery device for thermal power plants that not only allows workers to conveniently utilize waste heat from flue gas to heat the circulating water in the pipeline network, but also increases the heating temperature of the boiler intake air while reducing the flue gas temperature.

[0005] This utility model is achieved through the following technical solution: a waste heat recovery device for flue gas in a thermal power plant is provided, including a spraying mechanism and a water collection tank installed inside the chimney. The bottom of the water collection tank inside the chimney is connected to the input end of a dirt separator through a drainage pipe. A booster pump is fixedly connected to the output end of the dirt separator. The output end of the booster pump is connected to the input end of the heating source side of a plate heat exchanger. The output end of the heating source side of the plate heat exchanger is connected to the input end of a boiler air intake heating mechanism. The output end of the boiler air intake heating mechanism is connected to the spraying mechanism inside the chimney. The output end and input end of the heat source side of the plate heat exchanger are respectively connected to the input end and output end of a heat pump. The heating end of the heat pump is connected to a pipeline network.

[0006] In use, this invention utilizes a spray mechanism and a water collection tank installed inside the chimney. The bottom of the water collection tank is connected to the input end of a dirt separator via a drainage pipe. A booster pump is fixedly connected to the output end of the dirt separator. The output end of the booster pump is connected to the input end of the heating source side of a plate heat exchanger. The output end of the heating source side of the plate heat exchanger is connected to the input end of the boiler air intake heating mechanism. The output end of the boiler air intake heating mechanism is connected to the spray mechanism inside the chimney. The output and input ends of the heat source side of the plate heat exchanger are respectively connected to the input and output ends of a heat pump. The heating end of the heat pump is connected to a pipe network. When in use, the heat pump, booster pump, and dirt separator need to be started. This pumps the low-temperature solution from the boiler air intake heating mechanism to the spray mechanism inside the chimney, causing the spray mechanism to spray water outwards. The water falls from top to bottom, contacting the rising flue gas inside the chimney and absorbing heat from the flue gas, thus cooling and releasing the flue gas. The solution heats and condenses water vapor to whiten the flue gas. After absorbing heat, the solution falls into a collection tank inside the chimney. Under the pumping of a booster pump, it passes through a filter and enters the heating source side of a plate heat exchanger. This heats the water circulating in the heat source side of the plate heat exchanger, driven by the heat pump. The heat pump extracts heat from the circulating water in the heat source side of the plate heat exchanger to heat the circulating water in the pipe network. After heat exchange, the solution in the heating source side of the plate heat exchanger enters the boiler inlet air heating mechanism under the drive of the booster pump, thereby raising the temperature of the boiler inlet air. The low-temperature solution that has been used to heat the boiler hot air is then pumped back to the spray mechanism inside the chimney from the output end of the boiler inlet air heating mechanism, and the cycle repeats. This not only allows workers to conveniently use the waste heat of the flue gas to heat the circulating water in the pipe network, but also increases the heating temperature of the boiler inlet air while lowering the flue gas temperature.

[0007] Preferably, the boiler air inlet heating mechanism includes a spraying mechanism and a water collection tank installed in the primary air spraying heat source tower and the secondary air spraying heat source tower, respectively. The output end of the plate heat exchanger on the heating source side is connected to the spraying mechanism in the primary air spraying heat source tower and the secondary air spraying heat source tower. The water collection tank in the primary air spraying heat source tower and the secondary air spraying heat source tower is connected to the spraying mechanism in the chimney through a water supply mechanism. The boiler inlet air heating mechanism includes spraying mechanisms and water collection tanks installed in the primary air spray heat source tower and the secondary air spray heat source tower. The output end of the plate heat exchanger on the heating source side is connected to the spraying mechanisms in the primary air spray heat source tower and the secondary air spray heat source tower, respectively. The water collection tanks in the primary air spray heat source tower and the secondary air spray heat source tower are connected to the spraying mechanisms in the chimney through a water supply mechanism. When the device is in use, after heat exchange, the solution in the heating source side of the plate heat exchanger will enter the spraying mechanisms in the primary air spray heat source tower and the secondary air spray heat source tower under the drive of the booster pump, thereby causing the spraying mechanisms in the primary air spray heat source tower and the secondary air spray heat source tower to spray water outwards and respectively interact with the primary air spray heat source tower. The boiler inlet air of the primary and secondary air spray heat source towers comes into contact with the boiler inlet air. By utilizing the temperature difference between the boiler inlet air and the solution, the boiler inlet air absorbs heat from the solution, thereby increasing the boiler inlet air temperature of the primary and secondary air spray heat source towers and thus improving boiler efficiency. After the solution comes into contact with the boiler inlet air of the primary and secondary air spray heat source towers respectively, it falls into the water collection tanks inside the primary and secondary air spray heat source towers. The low-temperature solution in the water collection tanks of the primary and secondary air spray heat source towers is then pumped to the spray mechanism inside the chimney by the water supply mechanism. This allows the staff to reduce the flue gas temperature while increasing the heating temperature of the boiler inlet air.

[0008] Preferably, demisters are installed inside the chimney, the primary air spray heat source tower, and the secondary air spray heat source tower. By installing demisters inside the chimney, the primary air spray heat source tower, and the secondary air spray heat source tower, liquid droplets carried in the flue gas can be removed, preventing the solution from escaping outside the chimney with the flue gas.

[0009] Preferably, the spraying mechanism includes a spray pipe and a nozzle fixedly mounted on the spray pipe. The spraying mechanism, including the spray pipe and the nozzle, allows for convenient external spraying of water.

[0010] Preferably, the water delivery mechanism includes a connecting pipe that is connected to the water collection tank inside the primary air spray heat source tower and the secondary air spray heat source tower. The two connecting pipes are fixed to a water delivery pipe at the ends away from the water collection tanks via a T-junction. The end of the water delivery pipe away from the T-junction is connected to the input end of the spray pipe inside the chimney. A circulation pump is installed on the water delivery pipe. The water delivery mechanism includes connecting pipes that are connected to the water collection tanks inside the primary air spray heat source tower and the secondary air spray heat source tower. A water delivery pipe is fixed to the end of the two connecting pipes away from the water collection tanks via a T-junction. The end of the water delivery pipe away from the T-junction is connected to the inlet end of the spray pipe inside the chimney. A circulation pump is installed on the water delivery pipe. When the device is in use, by starting the circulation pump, the low-temperature solution in the water collection tanks inside the primary air spray heat source tower and the secondary air spray heat source tower is pumped through the connecting pipes and the T-junction to the water delivery pipe. Driven by the circulation pump, the solution enters the spray pipe inside the chimney from the water delivery pipe. This allows the staff to easily transport the low-temperature solution in the water collection tanks inside the primary air spray heat source tower and the secondary air spray heat source tower to the spray mechanism inside the chimney, so that the spray mechanism inside the chimney can spray water outwards.

[0011] Preferably, a plurality of plate heat exchangers are provided. By providing a plurality of plate heat exchangers, the heat exchange rate of the device can be increased.

[0012] The beneficial effects of this utility model are as follows: A spray mechanism and a water collection tank are installed inside the chimney. The bottom of the water collection tank is connected to the input end of a dirt separator via a drainage pipe. A booster pump is fixedly connected to the output end of the dirt separator. The output end of the booster pump is connected to the input end of the heating source side of the plate heat exchanger. The output end of the heating source side of the plate heat exchanger is connected to the input end of the boiler air intake heating mechanism. The output end of the boiler air intake heating mechanism is connected to the spray mechanism inside the chimney. The output and input ends of the heat source side of the plate heat exchanger are respectively connected to the input and output ends of the heat pump. The heating end of the heat pump is connected to the pipe network. When the device is in use, the heat pump, booster pump, and dirt separator need to be started, so that the low-temperature solution in the boiler air intake heating mechanism is pumped to the spray mechanism inside the chimney. This causes the spray mechanism inside the chimney to spray water outwards, which falls from top to bottom, contacting the rising flue gas inside the chimney and absorbing the heat from the flue gas, thereby cooling and releasing the flue gas. The solution heats and condenses water vapor to whiten the flue gas. After absorbing heat, the solution falls into a collection tank inside the chimney. Under the pumping of a booster pump, it passes through a filter and enters the heating source side of a plate heat exchanger. This heats the water circulating in the heat source side of the plate heat exchanger, driven by the heat pump. The heat pump extracts heat from the circulating water in the heat source side of the plate heat exchanger to heat the circulating water in the pipe network. After heat exchange, the solution in the heating source side of the plate heat exchanger enters the boiler inlet air heating mechanism under the drive of the booster pump, thereby raising the temperature of the boiler inlet air. The low-temperature solution that has been used to heat the boiler hot air is then pumped back to the spray mechanism inside the chimney from the output end of the boiler inlet air heating mechanism, and the cycle repeats. This not only allows workers to conveniently use the waste heat of the flue gas to heat the circulating water in the pipe network, but also increases the heating temperature of the boiler inlet air while lowering the flue gas temperature. Attached Figure Description

[0013] Figure 1 This is a front view of the structure of this utility model;

[0014] Figure 2 for Figure 1 Schematic diagram of part A in the middle;

[0015] Figure 3 for Figure 1 Structural perspective view;

[0016] Figure 4 for Figure 3 Schematic diagram of Part B in the middle section;

[0017] Figure 5 for Figure 3 Schematic diagram of the structure of part C;

[0018] Figure 6 This is a rear view of the structure of this utility model;

[0019] Figure 7 for Figure 6 Schematic diagram of the structure of part D in the middle;

[0020] Figure 8 for Figure 6 Structural perspective view;

[0021] Figure 9 for Figure 8 Schematic diagram of the structure of part E in the middle;

[0022] As shown in the figure:

[0023] 1. Chimney; 2. Primary air spray heat source tower; 3. Secondary air spray heat source tower; 4. Water supply pipe; 5. Connecting pipe; 6. Circulating pump; 7. Water collection tank; 8. T-joint pipe; 9. Demisting plate; 10. Spray pipe; 11. Spray head; 12. Pipeline; 13. Heat pump; 14. Plate heat exchanger; 15. Booster pump; 16. Sludge separator. Detailed Implementation

[0024] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0025] like Figures 1-9 The waste heat recovery device for flue gas in a thermal power plant, as shown in this utility model, includes a spraying mechanism and a water collection tank 7 installed inside a chimney 1. The bottom of the water collection tank 7 inside the chimney 1 is connected to the input end of a dirt separator 16 via a drainage pipe. A booster pump 15 is fixedly connected to the output end of the dirt separator 16. The output end of the booster pump 15 is connected to the input end of the heating source side of a plate heat exchanger 14. The output end of the heating source side of the plate heat exchanger 14 is connected to the input end of a boiler air intake heating mechanism. The output end of the boiler air intake heating mechanism is connected to the spraying mechanism inside the chimney 1. The output end and input end of the heat source side of the plate heat exchanger 14 are respectively connected to the input end and output end of a heat pump 13. The heating end of the heat pump 13 is connected to a pipe network 12.

[0026] The boiler air inlet heating mechanism includes a spraying mechanism and a water collection tank 7 installed in the primary air spraying heat source tower 2 and the secondary air spraying heat source tower 3. The output end of the plate heat exchanger 14 on the heating source side is connected to the spraying mechanism in the primary air spraying heat source tower 2 and the secondary air spraying heat source tower 3, respectively. The water collection tank 7 in the primary air spraying heat source tower 2 and the secondary air spraying heat source tower 3 is connected to the spraying mechanism in the chimney 1 through a water supply mechanism. When the device is in use, after heat exchange, the solution in the heating source side of the plate heat exchanger 14 will enter the spraying mechanism in the primary air spraying heat source tower 2 and the secondary air spraying heat source tower 3 under the drive of the booster pump 15, thereby causing the spraying mechanism in the primary air spraying heat source tower 2 and the secondary air spraying heat source tower 3 to spray water outward and respectively interact with the primary air spraying heat source tower 2 and the secondary air spraying heat source tower 3. The boiler inlet air of the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 comes into contact with each other, thereby utilizing the temperature difference between the boiler inlet air and the solution to allow the boiler inlet air to absorb heat from the solution, thus increasing the boiler inlet air temperature of the primary air spray heat source tower 2 and the secondary air spray heat source tower 3, and thus improving the boiler efficiency. After the solution comes into contact with the boiler inlet air of the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 respectively, it will fall into the water collection tank 7 in the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 respectively. The low temperature solution in the water collection tank 7 in the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 will be pumped again to the spraying mechanism in the chimney 1 through the water delivery mechanism. This allows the staff to reduce the flue gas temperature while increasing the heating temperature of the boiler inlet air. By installing demisters 9 inside the chimney 1, the primary air spray heat source tower 2, and the secondary air spray heat source tower 3, the demisters 9 can remove liquid droplets carried in the flue gas, preventing the solution from escaping outside the chimney 1 with the flue gas. The spraying mechanism includes a spray pipe 10 and nozzles 11 fixedly installed on the spray pipe 10, which facilitates the spraying mechanism to spray water outwards. The water delivery mechanism includes a connecting pipe 5 that is connected to the water collection tank 7 inside the primary air spray heat source tower 2 and the secondary air spray heat source tower 3. The end of the two connecting pipes 5 away from the water collection tank 7 is fixed to a water delivery pipe 4 through a tee pipe 8. The end of the water delivery pipe 4 away from the tee pipe 8 is connected to the input end of the spray pipe 10 inside the chimney 1. A circulation pump 6 is installed on the water delivery pipe 4. When the device is in use, by starting the circulation pump 6, the low temperature solution in the water collection tank 7 inside the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 is pumped through the connecting pipe 5 and the tee pipe 8 to the water delivery pipe 4, and then, driven by the circulation pump 6, it enters the spray pipe 10 inside the chimney 1 from the water delivery pipe 4. This makes it convenient for the staff to transport the low temperature solution in the water collection tank 7 inside the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 to the spray mechanism inside the chimney 1, so that the spray mechanism inside the chimney 1 sprays water outward. By providing several plate heat exchangers 14, the heat exchange rate of the device can be increased.

[0027] Combined with appendix Figure 1-9The method of using this utility model is as follows: First, the circulating pump 6, heat pump 13, booster pump 15, and dirt remover 16 need to be started. This allows the low-temperature solution in the water collection tank 7 of the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 to be pumped through the connecting pipe 5 and the three-way pipe 8 to the water supply pipe 4. Driven by the circulating pump 6, the solution then enters the spray pipe 10 inside the chimney 1 from the water supply pipe 4, causing the spray mechanism inside the chimney 1 to spray water outwards, which falls from top to bottom, thus contacting the rising flue gas inside the chimney 1. The process involves absorbing heat from the flue gas, thereby cooling the flue gas, releasing sensible heat, and condensing water vapor, thus achieving flue gas dewhitening. The heat-absorbing solution falls into the water collection tank 7 inside the chimney 1. Under the pumping of the booster pump 15, it passes through the filter 16 and enters the heating source side of the plate heat exchanger 14. This heat exchange is performed on the water circulating inside the heat source side of the plate heat exchanger 14 under the drive of the heat pump 13. The heat pump 13 extracts heat from the circulating water on the heat source side of the plate heat exchanger 14 to heat the water in the pipe network 12. The circulating water is heated, and the solution in the plate heat exchanger 14, after heat exchange, is driven by the booster pump 15 to enter the spray pipes 10 in the primary air spray heat source tower 2 and the secondary air spray heat source tower 3, respectively. This causes the solution to be sprayed outwards from the spray pipes 10 in the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 through the nozzles 11, and to contact the boiler inlet air of the primary air spray heat source tower 2 and the secondary air spray heat source tower 3, respectively. Utilizing the temperature difference between the boiler inlet air and the solution, the boiler inlet air absorbs... The heat in the solution increases the boiler inlet air temperature of the primary air spray heat source tower 2 and the secondary air spray heat source tower 3, thereby improving the boiler efficiency. After the solution comes into contact with the boiler inlet air of the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 respectively, it will fall into the water collection tank 7 in the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 respectively. The low temperature solution in the water collection tank 7 in the primary air spray heat source tower 2 and the secondary air spray heat source tower 3 will be pumped to the spraying mechanism in the chimney 1 again through the water delivery mechanism, and the cycle will continue.

[0028] Of course, the above description is not limited to the examples above. Technical features of this utility model not described can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model.

Claims

1. A waste heat recovery device for flue gas from a thermal power plant, characterized in that: It includes a spraying mechanism and a water collection tank (7) installed in the chimney (1). The bottom of the water collection tank in the chimney is connected to the input end of the dirt remover (16) through a drainage pipe. The output end of the dirt remover is fixedly connected to a booster pump (15). The output end of the booster pump is connected to the input end of the heating source side of the plate heat exchanger (14). The output end of the heating source side of the plate heat exchanger is connected to the input end of the boiler air intake heating mechanism. The output end of the boiler air intake heating mechanism is connected to the spraying mechanism in the chimney. The output end and input end of the heat source side of the plate heat exchanger are connected to the input end and output end of the heat pump (13) respectively. The heating end of the heat pump is connected to the pipeline network (12).

2. The waste heat recovery device for flue gas in a thermal power plant according to claim 1, characterized in that: The boiler air intake heating mechanism includes a spraying mechanism and a water collection tank installed in the primary air spraying heat source tower (2) and the secondary air spraying heat source tower (3). The output end of the plate heat exchanger on the heating source side is connected to the spraying mechanism in the primary air spraying heat source tower and the secondary air spraying heat source tower respectively. The water collection tank in the primary air spraying heat source tower and the secondary air spraying heat source tower is connected to the spraying mechanism in the chimney through a water supply mechanism.

3. The waste heat recovery device for flue gas in a thermal power plant according to claim 1, characterized in that: Demisting plates (9) are installed inside the chimney, primary air spray heat source tower and secondary air spray heat source tower.

4. The waste heat recovery device for flue gas in a thermal power plant according to claim 1, characterized in that: The spraying mechanism includes a spray pipe (10) and a nozzle (11) fixedly installed on the spray pipe.

5. The waste heat recovery device for flue gas in a thermal power plant according to claim 2, characterized in that: The water delivery mechanism includes a connecting pipe (5) that is connected to the water collection tank inside the primary air spray heat source tower and the secondary air spray heat source tower. A water delivery pipe (4) is fixedly connected to the end of the two connecting pipes away from the water collection tank through a three-way pipe (8). The end of the water delivery pipe away from the three-way pipe is connected to the input end of the spray pipe inside the chimney. A circulation pump (6) is installed on the water delivery pipe.

6. The waste heat recovery device for flue gas in a thermal power plant according to claim 4, characterized in that: Several plate heat exchangers are provided.

Images