Flue gas white smoke eliminating system
The design of a lithium bromide absorption heat pump unit and a boiler sharing a flue gas spray tower solves the problem of resource waste of direct-fired engines and boiler flue gas spray towers, realizes flue gas waste heat recovery and white smoke elimination, and reduces costs.
Patent Information
- Application Number
- CN202421808749.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-30
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-07-30
AI Technical Summary
In the existing technology, the flue gas spray towers of direct-fired engines and boilers are used in large quantities, and there is a lack of shared equipment when direct-fired engines and boilers are used at the same time, resulting in waste of resources and increased costs, and it is impossible to effectively recover the waste heat of the flue gas to avoid white smoke emissions.
A flue gas white smoke elimination system is designed. A lithium bromide absorption heat pump unit and a boiler share a flue gas spray tower. The flue gas temperature is reduced to about 30°C through the cold water system of the lithium bromide absorption heat pump unit, and the latent heat and sensible heat of the flue gas are recovered to achieve white smoke elimination.
It effectively reduces the flue gas temperature, recovers the waste heat of the flue gas, reduces the use of spray towers, reduces costs, meets users' needs for cost reduction and efficiency improvement, and avoids white smoke emissions.
Smart Images
Figure CN223345421U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of energy conservation and environmental protection, and relates to a flue gas whitening system. Background Art
[0002] The flue gas spray tower exists as a treatment equipment for environmentally friendly waste gas treatment. According to the working principle, it is divided into circulating water spray tower, alkali spray tower, acid spray tower, also known as pickling tower. According to the tower body material, it is divided into fiberglass spray tower, PP spray tower, stainless steel spray tower. The spraying method of the flue gas spray tower is usually to pass the flue gas from a position near the bottom of the spray tower into the flue gas spray tower, so that the flue gas rises from the bottom of the spray tower, and spray liquid is sprayed at the upper end of the interior of the spray tower, so that the flue gas can come into contact with the spray liquid during the rising process, thereby cooling the flue gas.
[0003] In light of environmental protection and the "dual carbon" initiative, waste heat generated by direct-fired engines and boilers should be recovered within the unit as much as possible, avoiding direct emission into the atmosphere, which could increase the greenhouse effect. Currently, the use of direct-fired engines and flue gas spray towers is limited to one direct-fired engine per flue gas spray tower, or one boiler per flue gas spray tower. The simultaneous use of a direct-fired engine and boiler with a single spray tower remains unavailable. This patent fills this gap in waste heat recovery systems, reducing the use of spray towers and meeting user needs for cost reduction and efficiency improvement. Utility Model Content
[0004] The purpose of this utility model is to overcome the deficiencies in the above-mentioned background technology and provide a flue gas whitening system, in which the lithium bromide absorption heat pump unit and the boiler share a flue gas spray tower. It fills the gap in the waste heat recovery system to meet the application in different fields. It meets the user's demand for cost reduction and efficiency improvement. The system mainly allows the 100°C flue gas generated by the lithium bromide absorption heat pump unit and the 100°C flue gas generated by the boiler to enter the flue gas spray tower at the same time, and the flue gas temperature is reduced to about 30°C through the cold water system of the lithium bromide absorption heat pump unit, and then discharged into the atmosphere. This part of the flue gas is discharged into the atmosphere after cooling, and at the same time the cold water system absorbs the latent heat and sensible heat in the flue gas to avoid the generation of white smoke (water vapor) in the air, so as to achieve the purpose of "whitening".
[0005] The technical solution adopted by the utility model to solve its technical problems is: a flue gas whitening system, including a lithium bromide absorption heat pump unit, a boiler, and a flue gas spray tower; the flue gas spray tower is arranged between the lithium bromide absorption heat pump unit and the boiler, and the lithium bromide absorption heat pump unit and the boiler are respectively connected to the lower side of the flue gas spray tower through pipelines; the flue gas spray tower includes a flue gas area and a tower bottom area, the flue gas area is arranged above the tower bottom area, and a partition plate is arranged in the flue gas area, and the partition plate divides the flue gas area into a unit flue gas area and a boiler flue gas area; a wire mesh demister is arranged on the top of the flue gas spray tower; a plurality of nozzles are arranged in the flue gas spray tower, and the nozzles are interspersed with the partition plate, and each nozzle is connected to a cold water inlet pipeline; the cold water of the nozzle is provided by the cold water outlet pipeline of the evaporator of the lithium bromide absorption heat pump unit, and a pH detector and a liquid level meter are arranged in the tower bottom area at the bottom of the flue gas spray tower.
[0006] The bottom area of the tower is also used to place the bottom liquid.
[0007] The bottom area of the tower is also connected to a dosing device; a water pump is provided on the pipeline connecting the dosing device and the bottom area of the tower.
[0008] A seal is provided at the connection between the nozzle and the partition plate.
[0009] A manual butterfly valve is installed on each cold water inlet pipe. Preferably, two nozzles are installed, one above the other. Two corresponding nozzles are installed on the cold water inlet pipe. The manual butterfly valve installed on the upper cold water inlet pipe is manual butterfly valve A; the manual butterfly valve installed on the lower cold water inlet pipe is manual butterfly valve B.
[0010] The bottom of the flue gas spray tower is connected in sequence to the circulating water pump, cold water inlet, evaporator, flow switch, cold water outlet and cold water main line; the cold water main line is divided into several branch lines, and each branch line is connected to the cold water inlet pipe.
[0011] The lithium bromide absorption heat pump unit is connected to the lower side of the flue gas spray tower through pipeline A; the flue gas outlet of the boiler is connected to the lower side of the flue gas spray tower through the boiler flue gas pipeline.
[0012] The boiler is also connected to a hot water outlet pipeline and a hot water inlet pipeline. A hot water outlet is arranged on the hot water outlet pipeline; a hot water inlet is arranged on the hot water inlet pipeline.
[0013] The lithium bromide absorption heat pump unit includes an evaporator, an absorber, a condenser, a high-temperature heat exchanger, a burner, and a high-temperature regenerator; the evaporator and the absorber are arranged in a cylinder, the burner and the high-temperature regenerator are arranged in a cylinder, the evaporator and the absorber are arranged on the left and right, and the high-temperature regenerator and the burner are arranged on the top and the bottom; the evaporator is connected to the condenser and the high-temperature regenerator in sequence; the high-temperature regenerator is connected to the solution pump, the high-temperature heat exchanger, and the absorber in sequence; the bottom of the absorber is connected to the circulation pump, the high-temperature heat exchanger, and the high-temperature regenerator in sequence; the cylinder where the high-temperature regenerator and the burner are arranged is connected to the lower side of the flue gas spray tower through pipe A.
[0014] The bottom of the evaporator is connected to the refrigerant pump and the top of the evaporator in sequence.
[0015] The cooling water pipeline is connected to the absorber and the condenser in sequence; a cooling water inlet and a cooling water outlet are respectively provided at both ends of the cooling water pipeline; the cooling water inlet is provided at one end of the absorber, and the cooling water outlet is provided at one end of the condenser.
[0016] The system is also equipped with a PLC control system. The evaporator, absorber, condenser, high-temperature heat exchanger, burner, high-temperature regenerator, solution pump, circulation pump, refrigerant pump, liquid level meter, pH detector, flue gas spray tower, wire mesh demister, nozzle, water pump, dosing device, boiler, and flow switch are respectively connected to the PLC control system, and are not limited to a specific model, as long as their working functions are realized.
[0017] A wire mesh demister is installed on the top of the flue gas spray tower. During the rising process of the flue gas, it will carry water vapor. After passing through the wire mesh demister, the water vapor condenses on the wire mesh demister and flows into the flue gas spray tower.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] This utility model provides a flue gas whitening elimination system. Flue gas from a lithium bromide absorption heat pump unit and boiler flue gas are simultaneously introduced into a spray tower to recover flue gas waste heat, lower the flue gas exhaust temperature, and eliminate white smoke (water vapor). Cold water from the lithium bromide absorption heat pump unit cools the flue gas, achieving waste heat recovery and whitening. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention is further described below with reference to the accompanying drawings and embodiments:
[0021] Figure 1 It is a structural diagram of a flue gas whitening system of the utility model.
[0022] In the figure, 1. Evaporator, 2. Absorber, 3. Condenser, 4. High-temperature heat exchanger, 5. Burner, 6. Pipeline A, 7. High-temperature regenerator, 8. Solution pump, 9. Circulating pump, 10. Refrigerant pump, 11. Cold water inlet, 12. Cold water outlet, 13. Cooling water inlet, 14. Cooling water outlet, 15. Circulating water pump, 16. Manual ball valve A, 17. Manual ball valve B, 18. Liquid level gauge, 19. pH meter, 20. Flue gas spray tower, 21. Tower bottom liquid, 22. Wire mesh demister, 23. Nozzle A, 24. Nozzle B, 25. Water pump, 26. Dosing device, 27. Boiler, 28. Boiler flue gas pipeline, 29. Hot water outlet, 30. Hot water inlet, 31. Flow switch, 32. Partition plate. DETAILED DESCRIPTION
[0023] The present invention is further described below with reference to the accompanying drawings, but the present invention is not limited to the following embodiments.
[0024] Example 1
[0025] A flue gas whitening system, such as Figure 1 As shown, it includes a lithium bromide absorption heat pump unit, a boiler 27, and a flue gas spray tower 20; the flue gas spray tower 20 is arranged between the lithium bromide absorption heat pump unit and the boiler 27, and the lithium bromide absorption heat pump unit and the boiler 27 are respectively connected to the lower side of the flue gas spray tower 20 through pipes; the flue gas spray tower 20 includes a flue gas area and a tower bottom area, the flue gas area is arranged above the tower bottom area, and a partition plate 32 is arranged in the flue gas area, which divides the flue gas area into a unit flue gas area and a boiler flue gas area; a wire mesh demister 22 is arranged on the top of the flue gas spray tower 20; a plurality of nozzles are arranged in the flue gas spray tower 20, and the nozzles are interspersed with the partition plate 32, and each nozzle is connected to a cold water inlet pipeline; the cold water of the nozzle is provided by the cold water outlet pipeline of the evaporator 1 of the lithium bromide absorption heat pump unit, and a pH detector 19 and a liquid level meter 18 are arranged in the bottom area of the bottom of the flue gas spray tower 20.
[0026] The tower bottom area is also used to place the tower bottom liquid 21.
[0027] The bottom area of the tower is also connected to a dosing device 26; a water pump 25 is installed on the pipeline connecting the dosing device 26 and the bottom area of the tower. The bottom area of the tower is also connected to a water supply tank, and the water supply pipeline of the water supply tank is connected to the pipeline of the water pump 25, and water is supplied by the water pump 25.
[0028] A seal is provided at the connection between the nozzle and the partition plate 32 .
[0029] Each cold water inlet pipe is equipped with a manual butterfly valve. Preferably, two nozzles are provided, one above the other. Two nozzles are provided for each cold water inlet pipe: nozzle A 24 at the top and nozzle B 25 at the bottom. The manual butterfly valve installed on the upper cold water inlet pipe is manual butterfly valve A16; the manual butterfly valve installed on the lower cold water inlet pipe is manual butterfly valve B17.
[0030] The bottom of the flue gas spray tower 20 is connected in sequence to the circulating water pump 15, the cold water inlet 11, the evaporator 1, the flow switch 31, the cold water outlet 12, and the cold water main line; the cold water main line is divided into several branch lines, and each branch line is connected to the cold water inlet pipeline.
[0031] The lithium bromide absorption heat pump unit is connected to the lower side of the flue gas spray tower 20 through the pipeline A6; the flue gas outlet of the boiler 27 is connected to the lower side of the flue gas spray tower 20 through the boiler flue gas pipeline 28.
[0032] The boiler 27 is further connected to a hot water outlet pipeline and a hot water inlet pipeline. A hot water outlet 29 is provided on the hot water outlet pipeline; a hot water inlet 30 is provided on the hot water inlet pipeline.
[0033] The lithium bromide absorption heat pump unit includes an evaporator 1, an absorber 2, a condenser 3, a high-temperature heat exchanger 4, a burner 5, and a high-temperature regenerator 7; the evaporator 1 and the absorber 2 are arranged in a cylinder, the burner 5 and the high-temperature regenerator 7 are arranged in a cylinder, the evaporator 1 and the absorber 2 are arranged on the left and right, and the high-temperature regenerator 4 and the burner 5 are arranged on the top and bottom; the evaporator 1 is connected to the condenser 3 and the high-temperature regenerator 7 in sequence; the high-temperature regenerator 7 is connected to the solution pump 8, the high-temperature heat exchanger 4, and the absorber 2 in sequence; the bottom of the absorber 2 is connected to the circulation pump 9, the high-temperature heat exchanger 4, and the high-temperature regenerator 7 in sequence; the cylinder in which the high-temperature regenerator 7 and the burner 5 are arranged is connected to the lower side of the flue gas spray tower 20 through the pipeline A 6.
[0034] The bottom of the evaporator 1 is connected to the refrigerant pump 10 and the top of the evaporator 1 in sequence.
[0035] The cooling water pipeline is connected to the absorber 2 and the condenser 3 in sequence; a cooling water inlet 13 and a cooling water outlet 14 are respectively provided at both ends of the cooling water pipeline; the cooling water inlet 13 is provided at one end of the absorber 2, and the cooling water outlet 14 is provided at one end of the condenser 3.
[0036] The system is also equipped with a PLC control system. The evaporator 1, absorber 2, condenser 3, high-temperature heat exchanger 4, burner 5, high-temperature regenerator 7, solution pump 8, circulation pump 9, refrigerant pump 10, liquid level meter 18, pH detector 19, flue gas spray tower 20, wire mesh demister 22, nozzle A 24, nozzle B 25, water pump 25, dosing device 26, boiler 27, and flow switch 31 are respectively connected to the PLC control system, and are not limited to a specific model, as long as their working functions are realized.
[0037] like Figure 1 As shown, the solution in the absorber 2 passes through the circulation pump 9 and the high-temperature heat exchanger 4 and enters the high-temperature regenerator 7. It is heated by the heat generated by the burner 5 and concentrated into a concentrated solution. It then passes through the high-temperature heat exchanger 4 and enters the absorber 2, absorbing the water vapor evaporated from the evaporator to become a dilute solution, and then circulates back and forth through the circulation pump 9. The cooling water absorbs the heat released from the concentrated solution in the absorber 2, then enters the condenser 3, absorbs the heat generated by the refrigerant vapor from the high-temperature regenerator 7, and then flows out to achieve a heating effect. The refrigerant vapor generated by the high-temperature regenerator 7 is cooled by the cooling water and becomes liquid water. It evaporates in the evaporator 1 and absorbs the heat of the cold water inlet water, reducing the temperature of this part of the water. The cold water then passes through the cold water outlet 12 to enter the flue gas spray tower 20 for cooling. After absorbing the waste heat of the flue gas, it enters the evaporator 1 to be cooled again. The reciprocating cycle achieves the whitening effect.
[0038] The flue gas generated by the complete combustion of the lithium bromide absorption heat pump unit enters the flue gas spray tower 20 at a temperature of about 100°C, is cooled by the cold water temperature of about 25°C from the lithium bromide absorption heat pump unit to about 30°C, and is discharged into the atmosphere. The water entering the bottom of the flue gas spray tower 20 absorbs the heat of the flue gas and becomes 35°C water, which enters the evaporator 1 for reciprocating circulation.
[0039] Flue gas generated by the lithium bromide absorption heat pump unit enters the flue gas spray tower 20, where it is cooled by the chilled water supplied by the unit and then discharged into the atmosphere. The chilled water circulates in a closed loop between the flue gas spray tower 20 via the circulating water pump 15. When the flow switch 31 sounds, it indicates insufficient water, requiring water replenishment from the water pump 25 to meet the needs of the lithium bromide absorption heat pump unit and the flue gas spray tower 20.
[0040] The lithium bromide absorption heat pump unit and the boiler 27 share the same flue gas spray tower 20. The flue gases between the two will affect each other. By adding a partition plate 32 in the middle of the flue gas spray tower, the flue gases of the two are separated, but the spray system is shared to avoid the interaction of the flue gases affecting the flue gas cooling and de-whitening effects.
[0041] The flue gas generated by the lithium bromide absorption heat pump unit and the boiler 27 enters from both sides of the lower part of the flue gas spray tower 20 and is separated by the middle partition. The two do not affect each other. The cold water entering the flue gas spray tower 20 enters from the upper part of the flue gas spray tower 20. The two perform countercurrent heat exchange to improve the utilization efficiency of the cold water and better reduce the flue gas temperature.
[0042] Cold water enters the flue gas spray tower 20 from the top and splits into two routes, passing through manual ball valve A16 and manual ball valve B17, respectively, and then through nozzles A24 and B25, respectively, cooling the flue gas twice. The first cooling step brings the flue gas temperature to approximately 55°C, and the second cooling step brings the temperature down to 30°C, resulting in a lower exhaust temperature. The opening of manual ball valve A16 must be greater than that of manual ball valve B17 because of the height difference, resulting in different positions. If the openings of manual ball valve A16 and manual ball valve B17 were the same, the amount of water entering manual ball valve B17 would be higher than that entering manual ball valve A16. To ensure the same amount of water entering both levels, the openings of manual ball valves A16 and B17 must be adjusted.
[0043] After exchanging heat with the flue gas, the cooling water's temperature rises to approximately 35°C. After recovering the sensible and latent heat of the flue gas, the cooling water enters the bottom of the flue gas spray tower 20, forming a bottom liquid 21. A liquid level gauge 18 is installed at the bottom of the tower. When the liquid level gauge 18 detects the liquid level, it indicates that the water level at the bottom of the tower is approaching a critical value, and it is necessary to increase the frequency and speed of the circulating water pump 15. Tests have shown that, under normal circumstances, the circulating water pump 15 can maintain a fixed frequency of 40Hz to meet normal liquid discharge needs. However, under abnormal circumstances, once the liquid level gauge is touched, it needs to operate at full frequency (60Hz) for 30 seconds to discharge the bottom liquid 21, thus preventing water from accumulating in the flue gas spray tower 20 and affecting heat exchange.
[0044] A pH detector 19 is installed at the bottom of the flue gas spray tower 20. Since the flue gas will produce some acidic substances (such as sulfides, etc.) after combustion, which will pollute the air and corrode the spray tower and pipelines, it is necessary to add some reagents (the main component is NAOH alkali solution) to the bottom of the flue gas spray tower 20. The pH detector 19 is used for detection. If the detection value is <7, a signal is fed back to the dosing device 26, and the dosing pump of the dosing device 26 adds medicine to the bottom of the tower. When the detection value is 7, the dosing pump stops working and the dosing process ends. In this way, the pH value of the cooling water is always neutral to avoid corrosion.
[0045] A wire mesh demister 22 is installed at the top of the flue gas spray tower 20. Its principle is to absorb small water droplets in the flue gas onto the wire mesh. During this repeated absorption process, the small droplets gradually become larger droplets. Gravity eventually pulls them back into the flue gas spray tower 20, thus separating the gas and liquid.
[0046] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications or improvements may be made to the present invention. Therefore, such modifications or improvements, without departing from the spirit of the present invention, are within the scope of protection claimed herein.
Claims
1. A flue gas whitening system, characterized in that: The invention comprises a lithium bromide absorption heat pump unit, a boiler (27), and a flue gas spray tower (20); the flue gas spray tower (20) is arranged between the lithium bromide absorption heat pump unit and the boiler (27); the lithium bromide absorption heat pump unit and the boiler (27) are respectively connected to the lower side of the flue gas spray tower (20) through pipelines; the flue gas spray tower (20) comprises a flue gas zone and a tower bottom zone; the flue gas zone is arranged above the tower bottom zone; a partition plate (32) is arranged in the flue gas zone; the partition plate (32) The flue gas area is divided into a unit flue gas area and a boiler flue gas area; a wire mesh demister (22) is provided on the top of a flue gas spray tower (20); a plurality of nozzles are provided in the flue gas spray tower (20), the nozzles being interspersed with a partition plate (32), and each nozzle being connected to a cold water inlet pipeline; cold water for the nozzles is provided by a cold water outlet pipeline of an evaporator (1) of a lithium bromide absorption heat pump unit, and a pH detector (19) and a liquid level meter (18) are provided in the bottom area of the flue gas spray tower (20).
2. A flue gas whitening system according to claim 1, characterized in that: A sealing member is provided at the connection between the nozzle and the partition plate (32).
3. A flue gas whitening system according to claim 1, characterized in that: A manual butterfly valve is provided on each cold water inlet pipe; two nozzles are provided, the two nozzles are provided one above the other, and two nozzles are provided corresponding to the cold water inlet pipe, the nozzle located at the upper end is nozzle A (24), and the nozzle located at the lower end is nozzle B (25); the manual butterfly valve provided on the cold water inlet pipe at the upper end is manual butterfly valve A (16); the manual butterfly valve provided on the cold water inlet pipe at the lower end is manual butterfly valve B (17).
4. A flue gas whitening system according to claim 1, characterized in that: The bottom of the flue gas spray tower (20) is connected in sequence to a circulating water pump (15), a cold water inlet (11), an evaporator (1), a flow switch (31), a cold water outlet (12), and a cold water main line; the cold water main line is divided into a plurality of branch lines, and each branch line is connected to a cold water inlet pipe.
5. The flue gas whitening system according to claim 1, characterized in that: The lithium bromide absorption heat pump unit is connected to the lower side of the flue gas spray tower (20) through a pipeline A (6); the flue gas outlet of the boiler (27) is connected to the lower side of the flue gas spray tower (20) through a boiler flue gas pipeline (28).
6. A flue gas whitening system according to claim 1, characterized in that: The boiler (27) is also connected to a hot water outlet pipeline and a hot water inlet pipeline. A hot water outlet (29) is provided on the hot water outlet pipeline; and a hot water inlet (30) is provided on the hot water inlet pipeline.
7. The flue gas whitening system according to claim 1, characterized in that: The lithium bromide absorption heat pump unit comprises an evaporator (1), an absorber (2), a condenser (3), a high-temperature heat exchanger (4), a burner (5), and a high-temperature regenerator (7); the evaporator (1) and the absorber (2) are arranged in a cylinder, the burner (5) and the high-temperature regenerator (7) are arranged in a cylinder, the evaporator (1) and the absorber (2) are arranged on the left and right, and the high-temperature regenerator (7) and the burner (5) are arranged on the top and bottom; the evaporator (1) is connected to the condenser (3) and the high-temperature regenerator (7) in sequence; the high-temperature regenerator (7) is connected to the solution pump (8), the high-temperature heat exchanger (4), and the absorber (2) in sequence; the bottom of the absorber (2) is connected to the circulation pump (9), the high-temperature heat exchanger (4), and the high-temperature regenerator (7) in sequence; the cylinder in which the high-temperature regenerator (7) and the burner (5) are arranged is connected to the lower side of the flue gas spray tower (20) through a pipeline A (6).
8. The flue gas whitening system according to claim 1, characterized in that: The bottom of the evaporator (1) is connected to the refrigerant pump (10) and the top of the evaporator (1) in sequence.
9. The flue gas whitening system according to claim 1, characterized in that: The cooling water pipeline is sequentially connected to the absorber (2) and the condenser (3); a cooling water inlet (13) and a cooling water outlet (14) are respectively provided at both ends of the cooling water pipeline; the cooling water inlet (13) is provided at one end of the absorber (2), and the cooling water outlet (14) is provided at one end of the condenser (3).