Waste heat coupling high-salinity wastewater zero discharge system of air cooling tower

Abstract

The utility model relates to the technical field of energy conservation and environmental protection, and discloses an air cooling tower waste heat coupling high-salinity wastewater zero discharge system which comprises an air cooling tower drum, an air cooling heat exchanger is arranged at the bottom of the air cooling tower drum, hot air is formed in the air cooling tower drum through the air cooling heat exchanger, and a high-temperature water inlet pipe and a low-temperature water return pipe are arranged on the air cooling heat exchanger; the evaporation tower drum is arranged in the air cooling tower drum, and an axial flow fan and a spraying layer are arranged in the evaporation tower drum; the wastewater concentration tank is arranged at the bottom of the evaporation tower drum and is communicated with a first booster pump, and the first booster pump is communicated with the spraying layer; the wastewater crystallizing pond is arranged on one side of the wastewater concentrating pond and is communicated with the first booster pump; according to the waste heat recovery system, low-quality waste heat of air in the tower drum of the air cooling tower is used as a heat source, additional heat sources such as steam do not need to be input, and the operation process of the system is energy-saving and environment-friendly.

Description

Technical Field

[0001] The utility model relates to the technical field of energy conservation and environmental protection, in particular to an air cooling tower waste heat coupled high-salt wastewater zero discharge system. Background Art

[0002] Flue gas desulfurization systems of thermal power generating units mostly use wet desulfurization. The wet desulfurization process system has low operating costs and high desulfurization efficiency, but a large amount of high-salt desulfurization wastewater will be generated during operation. Desulfurization wastewater mainly consists of two parts. One is gypsum slurry wastewater, which is mainly the discharge water of the absorption tower during the wet desulfurization of boiler flue gas. In order to maintain the balance of materials in the desulfurization slurry circulation system, prevent the chlorine concentration in the flue gas from exceeding the specified value and ensure the quality of gypsum, a certain amount of wastewater must be discharged from the system; the second is process flushing wastewater. Since the concentration of limestone slurry in the slurry storage tank and gypsum slurry in the absorption tower is very high, scaling and clogging are prone to occur, so the equipment needs to be continuously flushed during operation. This process flushing wastewater has also become an important part of desulfurization wastewater. At present, the most widely used high-salt desulfurization wastewater treatment method is mainly multi-effect evaporation technology. The equipment of multi-effect evaporation is complex, and its energy consumption is large, and the operating cost is also extremely expensive. Utility Model Content

[0003] The utility model aims to provide an air-cooling tower waste heat coupled high-salt wastewater zero-discharge system, aiming to solve or improve at least one of the above-mentioned technical problems.

[0004] To achieve the above purpose, the utility model provides the following solution: The utility model provides an air-cooling tower waste heat coupled high-salt wastewater zero-discharge system, including:

[0005] An air-cooling tower drum, wherein an air-cooling heat exchanger is arranged at the bottom of the air-cooling tower drum, hot air is formed in the air-cooling tower drum through the air-cooling heat exchanger, and a high-temperature water inlet pipe and a low-temperature water return pipe are arranged on the air-cooling heat exchanger;

[0006] An evaporation tower barrel, wherein the evaporation tower barrel is arranged inside the air cooling tower barrel, and an axial flow fan and a spray layer are arranged in sequence from top to bottom in the evaporation tower barrel, and the hot air is made to flow from below the spray layer toward the top of the evaporation tower barrel through the axial flow fan;

[0007] A wastewater concentration tank, the wastewater concentration tank is arranged at the bottom of the evaporation tower, the wastewater concentration tank is connected to a first booster pump, and the first booster pump is connected to the spray layer;

[0008] A wastewater crystallization tank, wherein the wastewater crystallization tank is arranged on one side of the wastewater concentration tank, and the wastewater crystallization tank is connected to the first booster pump;

[0009] The coil is arranged at the bottom of the wastewater crystallization pool, and the coil is connected with the high-temperature water inlet pipe and the low-temperature water return pipe through a circulation pipeline.

[0010] Optionally, the circulation pipeline includes a high-temperature branch and a low-temperature branch, the high-temperature branch is provided with a second boosting pump, the high-temperature branch is connected to the high-temperature water inlet pipe, the high-temperature branch is connected to the water inlet of the coil through the first water inlet pipeline, the low-temperature branch is connected to the low-temperature return pipe, and the low-temperature branch is connected to the return water port of the coil through the first return water pipeline.

[0011] Optionally, the high-temperature branch pipe is also connected to a steam-water heat exchanger through a second water inlet pipeline. The steam-water heat exchanger is arranged at the top of the evaporator tower. The steam-water heat exchanger is connected to the low-temperature branch pipe through a second return water pipeline.

[0012] Optionally, both the first water inlet pipeline and the second water inlet pipeline are provided with flow regulating valves.

[0013] Optionally, a droplet catcher is provided above the spray layer.

[0014] Optionally, a packing layer is provided below the spray layer, and the hot air passes through the packing layer.

[0015] The utility model discloses the following technical effects: an air-cooled heat exchanger is used to form hot air in the drum of an air-cooled tower as a heat source, and an axial flow fan and a first booster pump are used to atomize and spray high-salt desulfurization wastewater in a wastewater concentration tank from a spray layer, so that the atomized high-salt desulfurization wastewater contacts with the hot air, and the high-salt desulfurization wastewater is concentrated, thereby realizing secondary utilization of energy; the high-salt desulfurization wastewater after multiple concentrations is discharged into a wastewater crystallization pool by the first booster pump, and the high-temperature water in the high-temperature water inlet pipe is introduced into the coil through a circulation pipeline, and the heat of the high-temperature water is used to accelerate the evaporation of the concentrated high-salt desulfurization wastewater, thereby realizing secondary utilization of the high-temperature water, thereby realizing the utilization of low-quality waste heat of the air in the drum of the air-cooled tower as a heat source, without the need to invest in additional heat sources such as steam, and the system operation process is energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 It is a schematic diagram of the external structure of the utility model;

[0018] Figure 2 This is a schematic diagram of the internal structure of the air-cooling tower of the utility model;

[0019] Figure 3 for Figure 2 Top view of the .

[0020] In the figure: 1-1, air-cooling tower; 1-2, air-cooling heat exchanger; 1-3, high-temperature water inlet pipe; 1-4, low-temperature return pipe; 2-1, high-temperature branch pipe; 2-2, second booster pump; 2-3, flow regulating valve; 2-4, coil; 2-5, steam-water heat exchanger; 2-6, low-temperature branch pipe; 3-1, wastewater concentration tank; 3-2, wastewater crystallization tank; 3-3, packing layer; 3-4, spray layer; 3-5, droplet catcher; 3-6, axial flow fan; 3-7, evaporation tower; 3-8, first booster pump. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] Reference Figure 1-Figure 3 The utility model provides an air cooling tower waste heat coupled high-salt wastewater zero discharge system, comprising:

[0024] An air-cooling tower barrel 1-1, an air-cooling heat exchanger 1-2 is arranged at the bottom of the air-cooling tower barrel 1-1, hot air is formed in the air-cooling tower barrel 1-1 through the air-cooling heat exchanger 1-2, and a high-temperature water inlet pipe 1-3 and a low-temperature water return pipe 1-4 are arranged on the air-cooling heat exchanger 1-2;

[0025] The evaporation tower cylinder 3-7 is arranged inside the air cooling tower cylinder 1-1. The evaporation tower cylinder 3-7 is provided with an axial flow fan 3-6 and a spray layer 3-4 from top to bottom. The axial flow fan 3-6 allows hot air to flow from the bottom of the spray layer 3-4 toward the top of the evaporation tower cylinder 3-7.

[0026] The wastewater concentration tank 3-1 is arranged at the bottom of the evaporation tower 3-7, and the wastewater concentration tank 3-1 is connected to the first booster pump 3-8, and the first booster pump 3-8 is connected to the spray layer 3-4;

[0027] A wastewater crystallization tank 3-2, which is arranged on one side of the wastewater concentration tank 3-1, and is connected to the first booster pump 3-8;

[0028] The coil 2-4 is arranged at the bottom of the wastewater crystallization pool 3-2, and the coil 2-4 is connected with the high-temperature water inlet pipe 1-3 and the low-temperature water return pipe 1-4 through a circulation pipeline.

[0029] The air-cooled heat exchanger 1-2 is used to form hot air in the air-cooled tower barrel 1-1 as a heat source, and the high-salt desulfurization wastewater in the wastewater concentration tank 3-1 is atomized and sprayed from the spray layer 3-4 through the axial flow fan 3-6 and the first booster pump 3-8, so that the atomized high-salt desulfurization wastewater contacts with the hot air, and the high-salt desulfurization wastewater is concentrated to achieve secondary utilization of energy. After multiple concentrations, the high-salt desulfurization wastewater is discharged into the wastewater crystallization tank 3-2 by the first booster pump 3-8, and the high-temperature water in the high-temperature water inlet pipe 1-3 is introduced into the coil 2-4 through the circulation pipeline, and the heat of the high-temperature water is used to accelerate the evaporation of the concentrated high-salt desulfurization wastewater to achieve secondary utilization of high-temperature water, thereby realizing the utilization of low-quality waste heat of the air in the air-cooled tower barrel 1-1 as a heat source, without the need to invest in additional heat sources such as steam, and the system operation process is energy-saving and environmentally friendly.

[0030] When utilizing the heat of high-temperature water to evaporate high-salt desulfurization wastewater, the temperature of the high-temperature water is reduced, which can solve the problem of insufficient treatment of the air cooling system composed of the air cooling tower drum 1-1 to a certain extent, improve the heat exchange capacity of the air cooling system, and solve the shortcoming of insufficient cooling capacity of the air cooling system under high temperature environment in summer.

[0031] The inner wall of the wastewater crystallization pool 3-2 is treated with anti-corrosion and anti-seepage treatment to prevent high-salt desulfurization wastewater from penetrating the bottom of the pool and entering the groundwater to pollute the environment.

[0032] The concentration ratio of high-salt desulfurization wastewater is controlled between 3-4.

[0033] A further optimized solution is provided, in which the circulation pipeline includes a high-temperature branch pipe 2-1 and a low-temperature branch pipe 2-6. A second booster pump 2-2 is arranged on the high-temperature branch pipe 2-1. The high-temperature branch pipe 2-1 is connected with the high-temperature water inlet pipe 1-3. The high-temperature branch pipe 2-1 is connected with the water inlet of the coil 2-4 through the first water inlet pipe. The low-temperature branch pipe 2-6 is connected with the low-temperature return pipe 1-4. The low-temperature branch pipe 2-6 is connected with the return port of the coil 2-4 through the first return water pipe.

[0034] The high-temperature water in the high-temperature branch 2-1 is introduced into the coil 2-4 from the first water inlet pipeline through the second booster pump 2-2 for evaporation of high-salt desulfurization wastewater, and forms a high-temperature water circulation through the first return water pipeline and the low-temperature branch 2-6.

[0035] To further optimize the solution, the high-temperature branch pipe 2-1 is also connected to a steam-water heat exchanger 2-5 through a second water inlet pipeline. The steam-water heat exchanger 2-5 is arranged at the top of the evaporator tower 3-7. The steam-water heat exchanger 2-5 is connected to the low-temperature branch pipe 2-6 through a second return water pipeline.

[0036] The high-temperature water in the high-temperature branch pipe 2-1 is introduced into the steam-water heat exchanger 2-5 through the second water inlet pipeline, and the wet saturated exhaust gas at the top outlet of the evaporator tower tube 3-7 is heated by the steam-water heat exchanger 2-5. The hot air density is less than the cold air density, and the heated exhaust gas is converted from a saturated state to an unsaturated state, which can effectively raise the exhaust height of the evaporator tower tube 3-7 while preventing the wet saturated exhaust gas from condensing into droplets when it encounters cold, thereby avoiding the formation of colored plumes inside the air-cooling tower tube 1-1 and avoiding rain.

[0037] Furthermore, the height of the discharge port of the thermal evaporation tower 3-7 is set at more than 35m to prevent the waste gas and waste liquid from falling to the lower part of the air cooling tower 1-1 and corroding related equipment.

[0038] To further optimize the solution, flow regulating valves 2-3 are provided on both the first water inlet pipeline and the second water inlet pipeline.

[0039] To further optimize the solution, a droplet catcher 3-5 is provided above the spray layer 3-4.

[0040] After the liquid water collides with the droplet catcher 3-5, it condenses into large water droplets and then drops, which prevents the liquid water droplets from escaping into the air cooling tower 1-1 to the greatest extent. The droplet concentration at the outlet of the droplet catcher 3-5 is controlled at 10mg / Nm 3 the following.

[0041] To further optimize the solution, a packing layer 3-3 is provided below the spray layer 3-4, and the hot air passes through the packing layer 3-3.

[0042] The packing layer 3-3 can greatly expand the heat exchange surface, increase the contact area between the water film and the high-temperature air, and enhance the heat exchange effect.

[0043] The final crystallized salt in the wastewater crystallization pool 3-2 is mixed with fly ash, slag, lime and cement in a certain proportion and can be used to make permeable bricks, thus realizing the secondary utilization of resources.

[0044] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0045] The embodiments described above are only descriptions of the preferred methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. An air cooling tower waste heat coupled high-salinity wastewater zero discharge system, characterized in that: include: An air-cooling tower barrel (1-1), wherein an air-cooling heat exchanger (1-2) is arranged at the bottom of the air-cooling tower barrel (1-1), hot air is formed in the air-cooling tower barrel (1-1) through the air-cooling heat exchanger (1-2), and a high-temperature water inlet pipe (1-3) and a low-temperature water return pipe (1-4) are arranged on the air-cooling heat exchanger (1-2); An evaporation tower barrel (3-7), wherein the evaporation tower barrel (3-7) is arranged inside the air-cooling tower barrel (1-1), and an axial flow fan (3-6) and a spray layer (3-4) are arranged in sequence from top to bottom in the evaporation tower barrel (3-7), and the hot air flows from the bottom of the spray layer (3-4) toward the top of the evaporation tower barrel (3-7) through the axial flow fan (3-6); A wastewater concentration tank (3-1), wherein the wastewater concentration tank (3-1) is arranged at the bottom of the evaporation tower cylinder (3-7), and the wastewater concentration tank (3-1) is connected to a first booster pump (3-8), and the first booster pump (3-8) is connected to the spray layer (3-4); A wastewater crystallization pool (3-2), wherein the wastewater crystallization pool (3-2) is arranged on one side of the wastewater concentration pool (3-1), and the wastewater crystallization pool (3-2) is connected to the first booster pump (3-8); The coil (2-4) is arranged at the bottom of the wastewater crystallization pool (3-2), and the coil (2-4) is connected to the high-temperature water inlet pipe (1-3) and the low-temperature water return pipe (1-4) through a circulation pipeline.

2. The air cooling tower waste heat coupled high-salt wastewater zero discharge system according to claim 1 is characterized by: The circulation pipeline comprises a high-temperature branch pipe (2-1) and a low-temperature branch pipe (2-6); the high-temperature branch pipe (2-1) is provided with a second booster pump (2-2); the high-temperature branch pipe (2-1) is connected to the high-temperature water inlet pipe (1-3); the high-temperature branch pipe (2-1) is connected to the water inlet of the coil (2-4) through the first water inlet pipe; the low-temperature branch pipe (2-6) is connected to the low-temperature water return pipe (1-4); and the low-temperature branch pipe (2-6) is connected to the water return port of the coil (2-4) through the first water return pipe.

3. The air cooling tower waste heat coupled high-salt wastewater zero discharge system according to claim 2 is characterized by: The high-temperature branch pipe (2-1) is also connected to a steam-water heat exchanger (2-5) via a second water inlet pipeline. The steam-water heat exchanger (2-5) is arranged at the top of the evaporator barrel (3-7). The steam-water heat exchanger (2-5) is connected to the low-temperature branch pipe (2-6) via a second water return pipeline.

4. The air cooling tower waste heat coupled high-salt wastewater zero discharge system according to claim 3 is characterized by: The first water inlet pipeline and the second water inlet pipeline are both provided with flow regulating valves (2-3).

5. The air cooling tower waste heat coupled high-salt wastewater zero discharge system according to claim 1 is characterized by: A droplet catcher (3-5) is arranged above the spray layer (3-4).

6. The air cooling tower waste heat coupled high-salt wastewater zero-discharge system according to claim 1 is characterized by: A packing layer (3-3) is provided below the spray layer (3-4), and the hot air passes through the packing layer (3-3).

Images