Novel boiler continuous drainage self-heating desalting system

Abstract

The utility model discloses a novel boiler continuous drainage self-heating desalting system which comprises a heating evaporation and water supply system, a saline water discharging and cooling circulation system, a finished product water discharging system, a cold air system and a vacuum system. The heating evaporation and water supply system comprises a continuous blowdown flash tank, a flash tank, an evaporator and an air-cooled condenser which are connected in sequence, the evaporator is a multi-effect evaporator, the steam output end of the flash tank is connected with the steam input end of a first-effect evaporator of the evaporator, and the water drainage end of the flash tank is connected with a water spraying device of the first-effect evaporator of the evaporator; and the constant-drainage flash tank is connected with a water spraying device of a second-effect evaporator of the evaporator through a constant-drainage hot water pipeline. According to the scheme, a low-temperature multi-effect process mode and a multi-stage flash evaporation process mode are combined, heat of regular discharge and continuous discharge of the power plant is recycled, regular discharge and continuous discharge waste water is utilized for multiple times according to corresponding attributes in a grading mode, heat source loss is reduced, and the energy utilization rate is increased.

Description

Technical Field

[0001] The utility model belongs to the technical field of water treatment and heat recovery, and particularly relates to a novel self-heating desalination system for continuous blowdown of boilers. Background Art

[0002] The blowdown of boilers includes continuous blowdown (continuous discharge) and regular blowdown (periodic blowdown). Existing treatment methods, such as directly using it for workshop or unit water, or using its hot water or steam for heat exchange, etc., are relatively simple and direct, without fully considering the specific properties of continuous blowdown and regular blowdown sewage. The utilization rates of heat and water resources are not high, and the optimal energy recovery and utilization effect cannot be achieved. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a novel self-heating desalination system for continuous blowdown of boilers, solve the problem of low energy utilization rate of existing solutions, realize the utilization of the heat of regular blowdown and continuous blowdown in power plants, reduce heat source loss, and reuse the desalted and recycled wastewater.

[0004] According to the technical solution of the utility model, the utility model provides a novel self-heating desalination system for continuous blowdown of boilers, including a heating evaporation and water supply system, a brine discharge and cooling circulation system, a finished water discharge system, a cold air system, and a vacuum system;

[0005] The heating evaporation and water supply system includes a continuous blowdown flash tank, a flash tank, an evaporator, and an air-cooled condenser connected in sequence. Among them, the evaporator is a multi-effect evaporator. The steam output end of the flash tank is connected to the steam input end of the first-effect evaporator of the evaporator, and the drainage end of the flash tank is connected to the spray water device of the first-effect evaporator of the evaporator; it also includes a regular blowdown flash tank, and the regular blowdown flash tank is connected to the spray water device of the second-effect evaporator of the evaporator through a regular blowdown hot water pipeline;

[0006] The brine discharge and cooling circulation system includes a brine transfer pipeline. The brine discharge end of the last-effect evaporator of the evaporator is connected to the air inlet side of the air-cooled condenser through the brine transfer pipeline, and a brine transfer pump is provided in the brine transfer pipeline; the bottom of the air inlet side of the air-cooled condenser is connected to the cooling water pool of the air-cooled condenser; the cooling water pool is connected to the spray water device of the air-cooled condenser through a cooling circulation pipeline, a cooling circulation water pump is provided on the cooling circulation pipeline, and a concentrated brine discharge pipeline is also connected to the cooling circulation pipeline;

[0007] The finished water discharge system includes a finished water pipeline. The condensate pipeline drainage end of the air-cooled condenser is connected to the finished water pipeline, and a finished water pump is provided on the finished water pipeline;

[0008] The cold air system includes a cold air fan. The cold air output end of the cold air fan is connected with a side air supply pipeline and a lower air supply pipeline. The side air supply pipeline is communicated with the side of the air-cooled condenser, and the lower air supply pipeline is communicated with the cooling water pool of the air-cooled condenser;

[0009] The vacuum system includes a vacuum pipeline, which is communicated with the evaporator and the air-cooled condenser, and a vacuum pump is provided on the vacuum pipeline.

[0010] Further, an ejector and a booster pump are provided on the regular blowdown hot water pipeline.

[0011] Further, the air outlet side of the air-cooled condenser is also connected with the cold air fan through a hot air regulating air pipeline, and a regulating damper is provided on the hot air regulating air pipeline.

[0012] Further, the air-cooled condenser is located below the evaporator. The air outlet side of the air-cooled condenser is connected with a hot air discharge pipeline, and there is a spacing distance between the hot air discharge end of the hot air discharge pipeline and the evaporator.

[0013] Compared with the prior art, the beneficial technical effects of the present utility model are as follows:

[0014] In the novel boiler continuous blowdown self-heating desalination system of the present utility model, two process methods of low-temperature multi-effect and multi-stage flash evaporation are combined to recover and utilize the heat of the regular blowdown and continuous blowdown of the power plant. Among them, the regular blowdown and continuous blowdown waste water are used in multiple levels according to their corresponding properties, so as to output the finished water more energy-efficiently, reduce the heat source loss, and improve the energy utilization rate. Description of the Drawings

[0015] Figure 1 is a structural schematic diagram according to an embodiment of the present utility model.

[0016] Explanation of the reference numerals in the drawings:

[0017] 1. Evaporator; 2. Air-cooled condenser; 3. Flash tank; 4. Continuous blowdown flash tank; 5. Regular blowdown flash tank; 6. Vacuum pump; 7. Cold air fan; 8. Ejector; 9. Booster pump; 10. Brine transfer pump; 11. Cooling circulation water pump; 12. Finished water pump; 13. Regulating damper; 14. Regular blowdown hot water pipeline; 15. Brine transfer pipeline; 16. Cooling water pool; 17. Cooling circulation pipeline; 18. Concentrated brine discharge pipeline; 19. Finished water pipeline; 20. Side air supply pipeline; 21. Lower air supply pipeline; 22. Vacuum pipeline; 23. Hot air regulating air pipeline. Detailed Embodiments

[0018] The utility model provides a novel self-heating desalination system for continuous blowdown of boilers, which is applied to the recovery of the heat of the regular blowdown and continuous blowdown in power plants. It uses the self-heat of the boiler drainage to desalinate the drainage, solves the problem of low energy utilization rate in the existing solutions, realizes a more reasonable and efficient utilization of the drainage, reduces the heat source loss, and recovers and utilizes the wastewater after desalination.

[0019] Please refer to Figure 1 , a novel self-heating desalination system for continuous blowdown of boilers according to an embodiment of the utility model, includes a heating evaporation and water supply system, a brine discharge and cooling circulation system, a finished water discharge system, a cold air system, and a vacuum system.

[0020] The heating evaporation and water supply system includes a continuous blowdown flash tank 4, a flash tank 3, an evaporator 1, and an air-cooled condenser 2 that are connected in sequence. Among them, the evaporator 1 is a multi-effect evaporator (stage-by-stage evaporation system), and at least includes a first-effect evaporator, a second-effect evaporator, and a third-effect evaporator that are connected in sequence. The one located at the outermost end is called the last-effect evaporator, and the last-effect evaporator is connected to the air-cooled condenser 2. The basic structures of each effect evaporator and the air-cooled condenser 2 are generally the same, and both have a chamber, steam heat exchange pipelines inside the chamber, and a spray water device above the steam heat exchange pipelines. The steam heat exchange pipelines mainly contain hot steam, and the spray water device sprays relatively low-temperature brine-containing water onto the outer surface of the steam heat exchange pipelines, so that water evaporates in the chamber, enters the steam heat exchange pipelines of the next stage through the gas discharge pipelines connected to the chamber, and is heated stage by stage in this way, and finally condenses into water in the steam heat exchange pipelines of the air-cooled condenser 2. The steam output end of the flash tank 3 is connected to the steam input end of the first-effect evaporator of the evaporator 1, and the drainage end of the flash tank 3 is connected to the spray water device of the first-effect evaporator of the evaporator 1. It also includes a regular blowdown flash tank 5, the regular blowdown flash tank 5 is connected to the continuous blowdown flash tank 4, and the regular blowdown flash tank 5 is connected to the spray water device of the second-effect evaporator of the evaporator 1 through a regular blowdown hot water pipeline 14.

[0021] When the heating evaporation and water supply system is working, the heated hot water comes from the continuous blowdown flash tank and the regular blowdown flash tank. The continuous blowdown hot water goes to the flash tank of the self-heating desalination equipment, and the regular blowdown sewage is replenished into the water inlet side of the second effect of the evaporator as makeup water. The reason for using the regular blowdown sewage is that the salt content of the regular blowdown water is very low. Entering the system can ensure that the equipment is not prone to scaling. At the same time, the regular blowdown water still has a relatively high temperature, generally at 100 °C, which can improve the thermal efficiency of the system. At the same time, after reducing the discharge of the regular blowdown hot water, the cooling mixed water consumption can be reduced. Further preferably, a ejector 8 and a booster pump 9 are provided on the regular blowdown hot water pipeline 14. Since the installation position of the regular blowdown flash tank is relatively low, the pressure is generally not easy to supply to a higher position. Therefore, a booster pump needs to be set up for boosting water supply. Since the regular blowdown hot water is generally in a saturated state, the water pump is prone to cavitation. Therefore, a boosting ejector is set up to boost the water in front of the pump by the ejector to ensure that the water pump does not cavitate. The water supply system is divided into two paths. One path supplies water to the evaporation equipment, and the other path supplies water to the ejector; after the hot water passes through the flash tank, it enters the first effect of the evaporator as the heating heat source, or after the regular blowdown water passes through the ejector and the booster pump, it enters the water inlet side of the second effect of the evaporator, is heated step by step, and finally discharged to the air-cooled condenser.

[0022] The brine discharge and cooling circulation system includes a brine transfer pipeline 15. The brine discharge end at the bottom of the chamber of the last effect evaporator of the evaporator 1 is connected to the air inlet side of the air-cooled condenser 2 through the brine transfer pipeline 15, and a brine transfer pump 10 is provided in the brine transfer pipeline 15. The bottom of the air inlet side of the air-cooled condenser 2 is connected to the cooling water pool 16 at the bottom of the air-cooled condenser 2. The cooling water pool 16 is connected to the spray water device of the air-cooled condenser 2 through a cooling circulation pipeline 17. A cooling circulation water pump 11 is provided on the cooling circulation pipeline 17, and a concentrated brine discharge pipeline 18 is also connected to the cooling circulation pipeline 17.

[0023] The brine discharge and cooling circulation system can be divided into two parts. One part is that the brine in the last effect of the evaporator needs to be boosted and discharged from the negative pressure system. This system is provided with a brine transfer pump to drain the water to the air inlet side of the air-cooled condenser, and the cooled brine is discharged to the cooling water pool of the air-cooled condenser; the second part is the air-cooled spray water circulation and brine discharge. The system is provided with a cooling circulation water pump to boost the water pressure. One path of the pump outlet supplies water to the spray water device of the condenser, and the other path discharges the concentrated brine; the air-cooled condenser is provided with condenser spray water to further cool the brine discharged from the evaporator.

[0024] The finished water discharge system includes a finished water pipeline 19. The condensate pipeline drainage end of the air-cooled condenser 2 is connected to the finished water pipeline 19, and a finished water pump 12 is provided on the finished water pipeline 19.

[0025] The finished water discharge system is used to boost the pressure of the finished water of the final evaporator by setting a finished water pump, discharge it from the negative pressure system, and complete the output and external supply of the finished water.

[0026] The cold air system includes a cold air blower 7. The cold air output end of the cold air blower 7 is connected with a side air supply pipeline 20 and a lower air supply pipeline 21. The side air supply pipeline 20 is communicated with the side of the air-cooled condenser 2, and the lower air supply pipeline 21 is communicated with the cooling water tank 16 of the air-cooled condenser 2.

[0027] After the cold air of the cold air blower in the cold air system, the cold air enters the air-cooled condenser in two paths. One path is sent in from the side, and the other path is sent in from the lower part. The discharged hot air is directly discharged under normal circumstances. Preferably, the air outlet side of the air-cooled condenser 2 is also connected with the cold air blower 7 through a hot air regulating pipeline 23, and an adjusting air door 13 is arranged on the hot air regulating pipeline 23; in other words, a path for returning the discharged hot air to the blower inlet is set and an air-cooling adjusting air door is provided, so that part of the hot air can be sent into the blower inlet in cold winter seasons to adjust and control the air temperature at the blower inlet (increase the inlet air temperature) and prevent local icing and freezing damage in the condenser due to too low inlet air temperature. Preferably, the air-cooled condenser 2 is located below the evaporator 1, and the air outlet side of the air-cooled condenser 2 is connected with a hot air discharge pipeline. There is a spacing distance between the hot air discharge end (the end) of the hot air discharge pipeline and the evaporator 1, so that the discharged hot air is discharged at a certain height and at a certain distance from the evaporator, and the discharged humid hot air is kept away from the surface of the evaporator 1 to prevent water vapor from freezing on the surface of the equipment in winter.

[0028] The vacuum system includes a vacuum pipeline 22. The vacuum pipeline 22 is communicated with the evaporator 1 and the air-cooled condenser 2, and a vacuum pump 6 is arranged on the vacuum pipeline 22.

[0029] The main function of the vacuum system is to establish a vacuum during startup and timely extract the non-condensable gases of the equipment during operation to maintain the operating vacuum degree of the system. The non-condensable gases are discharged stage by stage and finally discharged to the condenser and then discharged from the system through the vacuum pump.

[0030] To sum up, the low-temperature multi-effect and multi-stage flash evaporation technologies are common technologies for thermal seawater desalination. In the new boiler continuous blowdown self-heating desalination system of the present invention, the low-temperature multi-effect and multi-stage flash evaporation process methods are combined to recover and utilize the heat of the fixed blowdown and continuous blowdown of the power plant, reduce the heat source loss, and improve the energy utilization rate. It should be noted that the specific structures of the basic components in the technical solution of the present invention can all adopt the existing technologies as long as they can achieve the corresponding required functions, so they will not be elaborated here.

Claims

1. A new type of boiler continuous blowdown self-heating desalination system, characterized in that It includes a heating evaporation and water supply system, a brine discharge and cooling circulation system, a finished water discharge system, a cold air system, and a vacuum system; The heating evaporation and water supply system includes a continuous blowdown flash tank (4), a flash tank (3), an evaporator (1), and an air-cooled condenser (2) connected in sequence. Among them, the evaporator (1) is a multi-effect evaporator. The steam output end of the flash tank (3) is connected to the steam input end of the first-effect evaporator of the evaporator (1), and the drain end of the flash tank (3) is connected to the spray water device of the first-effect evaporator of the evaporator (1); It also includes a regular blowdown flash tank (5), and the regular blowdown flash tank (5) is connected to the spray water device of the second-effect evaporator of the evaporator (1) through a regular blowdown hot water pipeline (14); The brine discharge and cooling circulation system includes a brine transfer pipeline (15). The brine discharge end of the last-effect evaporator of the evaporator (1) is connected to the air outlet side of the air-cooled condenser (2) through the brine transfer pipeline (15), and a brine transfer pump (10) is provided in the brine transfer pipeline (15); The bottom of the air outlet side of the air-cooled condenser (2) is connected to the cooling water tank (16) of the air-cooled condenser (2); The cooling water tank (16) is connected to the spray water device of the air-cooled condenser (2) through a cooling circulation pipeline (17), a cooling circulation water pump (11) is provided on the cooling circulation pipeline (17), and a concentrated brine discharge pipeline (18) is also connected to the cooling circulation pipeline (17); The finished water discharge system includes a finished water pipeline (19). The condensate pipeline drain end of the air-cooled condenser (2) is connected to the finished water pipeline (19), and a finished water pump (12) is provided on the finished water pipeline (19); The cold air system includes a cold air fan (7). The cold air output end of the cold air fan (7) is connected with a side air supply pipeline (20) and a lower air supply pipeline (21). The side air supply pipeline (20) is communicated with the side of the air-cooled condenser (2), and the lower air supply pipeline (21) is communicated with the cooling water tank (16) of the air-cooled condenser (2); The vacuum system includes a vacuum pipeline (22). The vacuum pipeline (22) is communicated with the evaporator (1) and the air-cooled condenser (2), and a vacuum pump (6) is provided on the vacuum pipeline (22).

2. The novel boiler continuous blowdown self-heating desalination system according to claim 1, characterized in that, A ejector (8) and a booster pump (9) are provided on the regular blowdown hot water pipeline (14).

3. The novel boiler continuous blowdown self-heating desalination system according to claim 1, wherein, The air outlet side of the air-cooled condenser (2) is also connected to the cold air fan (7) through a hot air regulating air pipeline (23), and a regulating air damper (13) is provided on the hot air regulating air pipeline (23).

4. The novel boiler continuous blowdown self-heating desalination system according to any one of claims 1 to 3, characterized in that, The air-cooled condenser (2) is located below the evaporator (1). The air outlet side of the air-cooled condenser (2) is connected with a hot air discharge pipeline, and there is a spacing distance between the hot air discharge end of the hot air discharge pipeline and the evaporator (1).

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