Low-temperature steam generation system capable of intelligently regulating and controlling gas production rate

Abstract

The utility model relates to a low-temperature steam generation system capable of intelligently regulating and controlling the gas production rate, which aims at solving the technical problem that the steam production rate is unstable when a coal-fired power plant fluctuates, and adopts the technical scheme that the system is provided with a plurality of groups of heat exchanger modules and an intelligent control system which are connected in parallel, and the intelligent control system inputs parameters related to boiler combustion; an intelligent neural network prediction model is obtained through analysis and training, an output unit outputs the group number of heat exchanger modules and liquid level values of a steam drum and a heat exchanger liquid level meter according to boiler loads, the group number of the input heat exchanger modules, the liquid level of the steam drum or the liquid level of a heat exchanger are regulated and controlled, intelligent control is achieved, and strip-shaped protrusions are arranged on the inner sides of fin heat exchange pipes. According to the system, the boiler load can be matched with the group number of the heat exchanger modules put into operation, the problem that steam parameters are lagged due to boiler load change of a traditional system is effectively solved, and collaborative coupling of desulfurization wastewater low-energy-consumption treatment and unit load is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of desulfurization and environmental protection technology of coal-fired power plants, specifically relating to a low-temperature steam generation system with intelligent control over gas production. Background Technology

[0002] Existing coal-fired power plant desulfurization wastewater treatment primarily employs multi-effect evaporation and concentration processes, with the heat source derived from flue gas waste heat. Specifically, a heat exchanger is installed in the flue gas duct between the dust collector and the first-effect heater. High-temperature flue gas (110-140℃) heats the circulating water within the heat exchanger, generating steam, which is then used to heat the desulfurization wastewater. Since steam output directly impacts the overall operation of the multi-effect evaporation and concentration system, stable steam output is crucial. However, due to factors such as power supply and demand balance, energy conservation and emission reduction policies, regional power grid dispatching, and new energy policies, the load of coal-fired power plants fluctuates dynamically. Load changes lead to fluctuations in flue gas volume and temperature, which in turn affect the steam output of the heat exchanger, resulting in unstable steam production.

[0003] Traditional flue heat exchangers have the following main problems:

[0004] 1. The heat exchanger in the flue has a small contact area with the circulating water, resulting in a large heat exchanger volume, high cost, and inconvenient installation.

[0005] 2. When the load of a coal-fired power plant fluctuates, the steam output is unstable and cannot be adjusted efficiently and quickly.

[0006] 3. Low level of automation control;

[0007] 4. It affects the efficient and stable operation of subsequent multi-effect evaporation and concentration processes. Utility Model Content

[0008] The purpose of this invention is to solve the above problems and provide a low-temperature steam generation system with intelligent control over gas production.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0010] A low-temperature steam generation system with intelligently adjustable gas production includes a steam drum, a steam pipe, a first-effect heater, a condensate tank, a water inlet pipe, a vacuum pump, a feed water pump, and a sewage tank. The steam drum is connected to the inlet of the first-effect heater via the steam pipe, and the outlet of the first-effect heater is connected to the inlet of the condensate tank. The bottom outlet of the condensate tank is connected to the steam drum via the water inlet pipe. A feed water pump is installed on the water inlet pipe. An exhaust pipe is connected to the top outlet of the condensate tank. A vacuum pump is installed on the exhaust pipe, and the other end extends into the atmosphere.

[0011] It also includes several sets of heat exchanger modules connected in parallel and an intelligent control system. The heat exchanger module includes a heat exchanger body, several finned heat exchange tubes, a riser pipe, a downcomer pipe, a connecting valve, and a three-way switching valve. The upper header on one side of the heat exchanger body is connected to the lower end of the riser pipe, and the upper end of the riser pipe is connected to the steam drum. The upper end of the downcomer pipe is connected to the steam drum, and the lower end is connected to the lower header on the other side of the heat exchanger body. The two ends of the finned heat exchange tubes are connected to the upper header and the lower header, respectively. The bottom of the several heat exchanger bodies is connected by a connecting valve. The three-way switching valve is located at the upper end of the riser pipe, with one end of the three-way switching valve leading to the steam drum and the other end leading to the atmosphere. A control valve is provided on the downcomer pipe. A first level gauge is provided on the heat exchanger body, and a second level gauge is provided on the steam drum. The heat exchanger body is connected to the sewage tank through a drain pipe, and a drain valve is provided on the drain pipe.

[0012] The intelligent control system includes an input unit, an analysis unit, and an output unit;

[0013] The input unit is used to input parameters related to boiler combustion, including boiler load, coal feed rate, primary air volume, secondary air volume, flue gas temperature, and flue gas volume.

[0014] The analysis unit includes a data processing unit and a model training unit. The data processing unit is used to process the data from the input unit. The model training unit is used to construct an intelligent neural network prediction model and train the intelligent neural network prediction model based on the data processed by the data processing unit to obtain the trained intelligent neural network prediction model.

[0015] The output unit is used to output the number of heat exchanger modules and the liquid level values ​​of the first and second liquid level gauges based on the boiler load through an intelligent neural network prediction model.

[0016] The intelligent control system is electrically connected to the connecting valve, control valve, three-way switching valve, first level gauge, second level gauge, vacuum pump, water supply pump, and drain valve, respectively.

[0017] Furthermore, the outer wall of the finned heat exchange tube is uniformly provided with spiral fins, and the inner wall is uniformly provided with protrusions.

[0018] Furthermore, the protrusion can be any one of the following: serrated, spherical, or smooth.

[0019] Furthermore, the upper edge of the riser pipe is at the same horizontal level as the center line of the steam drum.

[0020] Furthermore, the steam drum is also equipped with a pressure monitor and a temperature monitor, and the steam pipe is equipped with a steam flow meter. The pressure monitor, temperature monitor, and steam flow meter are electrically connected to the intelligent control system.

[0021] Compared with the prior art, the beneficial effects of this utility model are:

[0022] 1. This utility model adopts several sets of heat exchanger modules connected in parallel and an intelligent control system. Through an intelligent neural network prediction model, the boiler load is matched with the number of heat exchanger modules put into operation. When the boiler load increases, the system will predict and start the appropriate number of heat exchanger modules to meet the steam demand in a timely manner. This effectively solves the problem of steam parameter lag caused by changes in boiler load in traditional systems, thereby achieving stable and reliable operation of the multi-effect evaporation system and realizing the synergistic coupling of low-energy treatment of desulfurization wastewater and unit load.

[0023] 2. The inner wall of the finned heat exchange tube of this utility model is evenly distributed with a number of serrated, spherical, or smooth strip-shaped protrusions. The protrusion design greatly increases the contact area between the finned heat exchange tube and the circulating water, reduces the volume of the heat exchanger body, lowers the equipment cost, and improves the heat transfer coefficient of the heat exchanger body. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0025] Figure 2 This is a schematic diagram of the heat exchanger module structure of this utility model;

[0026] Figure 3 This is a schematic diagram of the connection structure of the three-way switching valve in the heat exchanger module of this utility model;

[0027] Figure 4 This is a schematic diagram of the finned heat exchanger tube structure of this utility model;

[0028] Figure 5 This is a schematic diagram of the serrated protrusion structure on the inner wall of the finned heat exchange tube of this utility model.

[0029] Figure 6 This is a schematic diagram of the spherical protrusion structure on the inner wall of the finned heat exchange tube of this utility model.

[0030] Figure 7 This is a schematic diagram of the smooth strip-shaped protrusion on the inner wall of the finned heat exchange tube of this utility model.

[0031] Figure 8 This is a schematic diagram of the intelligent control system structure of this utility model;

[0032] In the diagram: 1. Heat exchanger module; 2. Connecting valve; 3. Rising pipe; 4. Downcomer; 5. Control valve; 6. Steam drum; 7. Three-way switching valve; 8. Steam pipe; 9. First-effect heater; 10. Condensate tank; 11. Inlet pipe; 12. First level gauge; 13. Second level gauge; 14. Pressure monitor; 15. Temperature monitor; 16. Steam flow meter; 17. Heat exchanger body; 18. Finned heat exchange tube; 19. Fin; 20. Tube; 21. Protrusion; 22. Vacuum pump; 23. Feed water pump; 24. Sewage tank; 25. Drain valve. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] like Figure 1-7 As shown, a low-temperature steam generation system with intelligently adjustable steam production includes a steam drum 6, a steam pipe 8, a first-effect heater 9, a condensate tank 10, a water inlet pipe 11, a vacuum pump 22, a feed water pump 23, and a sewage tank 24. The steam drum 6 is connected to the inlet of the first-effect heater 9 through the steam pipe 8. A steam flow meter 16 is installed on the steam pipe 8 to monitor the steam production at all times. The outlet of the first-effect heater 9 is connected to the inlet of the condensate tank 10. The bottom outlet of the condensate tank 10 is connected to the steam drum 6 through the water inlet pipe 11. A feed water pump 23 is installed on the water inlet pipe 11. An exhaust pipe is connected to the top outlet of the condensate tank 10. A vacuum pump 22 is installed on the exhaust pipe, and the other end extends to the atmosphere.

[0035] The system also includes 4-6 sets of heat exchanger modules 1 connected in parallel and an intelligent control system. Each heat exchanger module 1 can be controlled independently. Each heat exchanger module 1 includes a heat exchanger body 17, several finned heat exchange tubes 18, a riser pipe 3, a downcomer pipe 4, a connecting valve 2, and a three-way switching valve 7. The upper header on one side of the heat exchanger body 17 is connected to the lower end of the riser pipe 3, and the upper end of the riser pipe 3 is connected to the steam drum 6, with its upper edge at the same horizontal level as the centerline of the steam drum 6. The upper end of the downcomer pipe 4 is connected to the steam drum 6. The lower end is connected to the lower header on the other side of the heat exchanger body 17. The two ends of the finned heat exchange tube 18 are connected to the upper header and the lower header, respectively. The outer wall of the tube 20 of the finned heat exchange tube 18 is uniformly provided with spiral fins 19, and the inner wall is uniformly provided with serrated protrusions 21. Taking the φ45 tube 20 as an example, after adding the serrated protrusions 21 on the inner wall, the contact area between the heat exchanger side and the circulating water can be increased by about 3.85 times, which greatly improves the overall heat transfer coefficient of the heat exchanger, while not increasing the water-side resistance inside the heat exchanger.

[0036] The bottom of the 4-6 heat exchanger bodies 17 are connected by a connecting valve 2. The three-way switching valve 7 is located at the upper end of the riser pipe 3, with one end of the three-way switching valve 7 leading to the steam drum 6 and the other end leading to the atmosphere. The downcomer pipe 4 is equipped with a control valve 5. The heat exchanger body 17 is equipped with a first level gauge 12. The steam drum 6 is equipped with a second level gauge 13, a pressure monitor 14, and a temperature monitor 15. The pressure monitor 14, temperature monitor 15, and steam flow meter 16 are electrically connected to the intelligent control system. The pressure monitor 14 and temperature monitor 15 can monitor the pressure and temperature inside the steam drum 6 in real time. The heat exchanger body 17 is connected to the sewage tank 24 through a drain pipe, and a drain valve 25 is provided on the drain pipe.

[0037] like Figure 8 As shown, the intelligent control system includes an input unit, an analysis unit, and an output unit;

[0038] The input unit is used to input parameters related to boiler combustion, including boiler load, coal feed rate, primary air volume, secondary air volume, flue gas temperature, and flue gas volume.

[0039] The analysis unit includes a data processing unit and a model training unit. The data processing unit is used to process the data from the input unit. The model training unit is used to construct an intelligent neural network prediction model and train the intelligent neural network prediction model based on the data processed by the data processing unit to obtain the trained intelligent neural network prediction model.

[0040] The output unit is used to output the number of heat exchanger modules 1 and the liquid level values ​​of the first liquid level gauge 12 and the second liquid level gauge 13 based on the boiler load through an intelligent neural network prediction model.

[0041] The intelligent control system is electrically connected to the connecting valve 2, the control valve 5, the three-way switching valve 7, the first level gauge 12, the second level gauge 13, the vacuum pump 22, the water supply pump 23, and the drain valve 25.

[0042] The protrusion 21 can also be either a spherical protrusion or a smooth strip.

[0043] The operation process of this utility model:

[0044] When the system is running, the vacuum pump 22 is first started to establish a negative pressure environment. The system pressure is controlled according to the required saturated steam temperature. The circulating water in the heat exchanger body 17 is heated by the flue gas and enters the steam drum 6 through the riser pipe 3. After some water is turned into saturated steam, it enters the first-effect heater 9 through the steam pipe 8 to heat the desulfurization wastewater inside. After heating, the steam turns into condensate and enters the condensate tank 10. The condensate is then transported to the steam drum 6 through the feed water pump 23 along the water inlet pipe 11 to replenish the water. The water in the steam drum 6 enters the heat exchanger body 17 through the downcomer pipe 4 for reheating. This cycle repeats continuously.

[0045] When the boiler load is 50-69%, a total of 8 modules of the heat exchanger are put into operation. The intelligent control system adjusts the liquid level in the steam drum 6 by controlling the opening and closing of the feed water pump 23, so that it matches the output value of the first liquid level gauge 12 or the second liquid level gauge 13. The specific corresponding liquid levels are shown in Table 2.

[0046] When the boiler load is greater than 70%, the flue gas temperature is high and the flue gas volume is large. At this time, the intelligent control system will shut down one or more heat exchanger modules 1: the control valve 5 on the corresponding downcomer 4 will be closed, the three-way switching valve 7 on the riser 3 will be switched to the atmospheric side, and the steam generated in the heat exchanger module 1 will be discharged into the atmosphere, and the module will stop operating.

[0047] When the unit load is low, the flue gas temperature is low, and the flue gas volume is small, the module is put back into operation: that is, the control valve 5 on the corresponding downcomer 4 is opened, the three-way switching valve 7 on the corresponding riser 3 is switched to the steam drum 6 side, the steam generated in the heat exchanger module 1 is discharged into the steam drum 6, and the module is put into operation in the system.

[0048] Because the boiler load fluctuates continuously, the intelligent neural network prediction model is used to match the boiler load with the heat exchanger module 1 that is put into operation, ensuring stable steam output when the load fluctuates. The intelligent neural network prediction model is used to match the boiler load with the number of heat exchanger modules 1 that are put into operation, which solves the problem of large lag and delay of low temperature steam parameters caused by boiler load changes, making it difficult for the multi-effect evaporation system to operate reliably. It realizes the synergistic coupling of low-energy treatment of desulfurization wastewater and wide load range (35~100%) of the unit.

[0049] The load-number of heat exchanger groups in operation and the corresponding liquid levels of the steam drum and heat exchanger body during actual system operation are shown in Table 1, and the specific water level values ​​are shown in Table 2.

[0050] Table 1. Relationship between load, number of heat exchanger units in operation, and liquid levels in the steam drum and heat exchanger body.

[0051]

[0052] Table 2. Water level values ​​during actual system operation

[0053]

Claims

1. A low-temperature steam generation system with intelligent controllable gas production, comprising a steam drum (6), a steam pipe (8), a first-effect heater (9), a condensate tank (10), a water inlet pipe (11), a vacuum pump (22), a feed water pump (23), and a sewage tank (24). The steam drum (6) is connected to the inlet of the first-effect heater (9) through the steam pipe (8), and the outlet of the first-effect heater (9) is connected to the inlet of the condensate tank (10). The bottom outlet of the condensate tank (10) is connected to the steam drum (6) through the water inlet pipe (11). The feed water pump (23) is provided on the water inlet pipe (11). The top outlet of the condensate tank (10) is connected to an exhaust pipe. The exhaust pipe is provided with a vacuum pump (22), and the other end extends into the atmosphere. Its features are, It also includes several sets of heat exchanger modules (1) connected in parallel and an intelligent control system. The heat exchanger module (1) includes a heat exchanger body (17), several finned heat exchange tubes (18), a riser (3), a downcomer (4), a connecting valve (2), and a three-way switching valve (7). The upper header on one side of the heat exchanger body (17) is connected to the lower end of the riser (3), and the upper end of the riser (3) is connected to the steam drum (6). The upper end of the downcomer (4) is connected to the steam drum (6), and the lower end is connected to the lower header on the other side of the heat exchanger body (17). The two ends of the finned heat exchange tubes (18) are... Do not connect to the upper and lower headers. The bottom of the heat exchanger bodies (17) are connected by a connecting valve (2). The three-way switching valve (7) is set at the upper end of the riser pipe (3). One end of the three-way switching valve (7) is connected to the steam drum (6) and the other end is connected to the atmosphere. The downcomer pipe (4) is equipped with a control valve (5). The heat exchanger body (17) is equipped with a first level gauge (12) and the steam drum (6) is equipped with a second level gauge (13). The heat exchanger body (17) is connected to the sewage tank (24) through a drain pipe. The drain pipe is equipped with a drain valve (25). The intelligent control system includes an input unit, an analysis unit, and an output unit; The input unit is used to input parameters related to boiler combustion, including boiler load, coal feed rate, primary air volume, secondary air volume, flue gas temperature, and flue gas volume. The analysis unit includes a data processing unit and a model training unit. The data processing unit is used to process the data from the input unit. The model training unit is used to construct an intelligent neural network prediction model and train the intelligent neural network prediction model based on the data processed by the data processing unit to obtain the trained intelligent neural network prediction model. The output unit is used to output the number of heat exchanger modules (1), the level values ​​of the first level gauge (12) and the second level gauge (13) according to the boiler load through the intelligent neural network prediction model; The intelligent control system is electrically connected to the connecting valve (2), the control valve (5), the three-way switching valve (7), the first level gauge (12), the second level gauge (13), the vacuum pump (22), the water supply pump (23), and the drain valve (25).

2. The low-temperature steam generation system with intelligently adjustable gas production as described in claim 1, characterized in that, The outer wall of the tube (20) of the finned heat exchange tube (18) is uniformly provided with spiral fins (19), and the inner wall is uniformly provided with protrusions (21).

3. The low-temperature steam generation system with intelligently adjustable gas production according to claim 2, characterized in that, The protrusion (21) can be any one of the following: serrated, spherical, or smooth.

4. The low-temperature steam generation system with intelligently adjustable gas production according to claim 1, characterized in that, The upper edge of the riser pipe (3) is at the same horizontal level as the center line of the steam drum (6).

5. A low-temperature steam generation system with intelligently adjustable gas production as described in claim 1, characterized in that, The steam drum (6) is also equipped with a pressure monitor (14) and a temperature monitor (15), and the steam pipe (8) is equipped with a steam flow meter (16). The pressure monitor (14), temperature monitor (15), and steam flow meter (16) are electrically connected to the intelligent control system.

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