A wastewater treatment system and method for comprehensive utilization of waste heat from air-cooling island and solar energy

Abstract

The present invention relates to a wastewater treatment system for comprehensive utilization of waste heat and solar energy in an air-cooled island, comprising: a steam distribution pipe, an axial flow fan, a cooling triangle downstream tube bundle, a cooling triangle countercurrent tube bundle, a wastewater inlet triple box, a desulfurization wastewater flow meter, a desulfurization wastewater thermometer, a desulfurization wastewater feed pipe, a desulfurization wastewater feed pump, a top water tank, a ridge water tank, a V-shaped guide evaporation tank, a wastewater collecting tank, an adjustable tee and a desulfurization wastewater circulating water pump, a desulfurization wastewater circulating loop pipe, a desulfurization wastewater self-return pipe and a desulfurization wastewater pool. The beneficial effects of the present invention are: the V-shaped guide evaporation tank is compactly arranged without affecting the heat dissipation of the air-cooled island; when the outdoor temperature is high, it can reduce the direct sunlight on the air-cooled condenser and increase the heat exchange effect of the air-cooled condenser; the desulfurization wastewater self-return pipe is connected to the desulfurization wastewater pool, and the temperature of the desulfurization wastewater pool is maintained when the outdoor temperature is low in winter, and the heat exchange effect of the air-cooled condenser is increased, and it can be applied to the field of wastewater evaporation reduction treatment.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection, and in particular comprises a wastewater treatment system and method for comprehensive utilization of waste heat from an air-cooling island and solar energy. Background Art

[0002] As the final link in the cascade utilization of wastewater, desulfurization wastewater from power plants has always been a difficult point in wastewater treatment in the thermal power industry due to its high salt content, complex composition, and certain corrosiveness. It is also the key to achieving zero wastewater discharge from coal-fired units. Its treatment process has always received continuous attention in the industry.

[0003] An air-cooled condenser is a condenser that directly cools the exhaust steam of a steam turbine through air, and performs heat exchange between air and exhaust steam. It is composed of a tube bundle of elliptical flat base tubes brazed with aluminum fins. The cooling air required for the direct air-cooling system is usually directly supplied by mechanical ventilation. It is mainly used in the dry and rainy areas in the northwest of my country where water resources are scarce. The exhaust steam of the steam turbine is sent to the outdoor air-cooled condenser through a thick exhaust pipe. The axial cooling fan makes the air flow through the outer surface of the radiator, so that the exhaust steam condenses into water and enters the hot well, and then is sent to the heat recovery system of the steam turbine through the condensate pump.

[0004] The cooling principle of the air-cooled condenser is to exchange heat between air and exhaust steam. In summer, the outdoor temperature is high. The temperature of the air-cooled condenser under direct sunlight will be much higher than the ambient temperature, and the heat exchange effect of the air-cooled condenser will be greatly reduced. In summer, the exhaust temperature of the air-cooled condenser is often higher than 55°C or even close to 60°C, and the vacuum degree also drops from 8kPa in winter to 20kPa. The reduction in vacuum degree has adverse effects such as increased coal consumption for power generation, limited peak power generation in summer, cavitation in the vacuum pump, and increased circulating water consumption. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a wastewater treatment system and method for comprehensive utilization of waste heat from an air-cooled island and solar energy.

[0006] The wastewater treatment system for comprehensive utilization of waste heat and solar energy in the air-cooling island includes: a steam distribution pipe, an axial flow fan, a cooling triangle downstream tube bundle, a cooling triangle countercurrent tube bundle, a wastewater inlet triple box, a desulfurization wastewater flow meter, a desulfurization wastewater thermometer, a desulfurization wastewater feed pipe, a desulfurization wastewater feed pump, a top water tank, a roof water tank, a V-shaped diversion evaporation tank, a wastewater collecting tank, an adjustable tee and a desulfurization wastewater circulating water pump, a desulfurization wastewater circulating loop pipe, a desulfurization wastewater self-return pipe and a desulfurization wastewater pool;

[0007] The cooling triangle downstream tube bundle, the cooling triangle countercurrent tube bundle and the steam distribution pipe are connected and meet at the outlet of the steam distribution pipe; the cooling triangle downstream tube bundle and the cooling triangle countercurrent tube bundle are opened at a certain angle directly downward and are in a ridge-like inverted V shape as a whole; the axial flow fan is arranged directly below the outlet of the steam distribution pipe;

[0008] The wastewater inlet triple box and the water outlet at the bottom of the desulfurization wastewater pool are both connected to the inlet of the desulfurization wastewater feed pump through a pipeline, the outlet of the desulfurization wastewater feed pump is connected to one end of the desulfurization wastewater feed pipe, and the other end of the desulfurization wastewater feed pipe is connected to the water inlet of the top water tank; the desulfurization wastewater feed pipe is provided with a desulfurization wastewater flowmeter and a desulfurization wastewater thermometer; the water outlet of the top water tank is connected to the water inlet of the ridge water tank, and the water outlets at both ends of the ridge water tank are respectively connected to the two starting ends of the V-shaped diversion evaporation tank, which takes the ridge of the air-cooling island as the symmetry axis, is parallel to and higher than the cooling triangle downstream tube bundle and the cooling triangle countercurrent tube bundle; wastewater collecting tanks are respectively provided directly below the ends of both sides of the V-shaped diversion evaporation tank;

[0009] The outlets of the two wastewater collecting tanks are both connected to the inlet of the adjustable tee and the desulfurization wastewater circulating water pump; the outlets of the adjustable tee and the desulfurization wastewater circulating water pump are divided into two routes: one route is connected to one end of the desulfurization wastewater circulating loop pipe, and the other end of the desulfurization wastewater circulating loop pipe is connected to the water inlet of the top water tank; the other route is connected to one end of the desulfurization wastewater self-return pipe, and the other end of the desulfurization wastewater self-return pipe is connected to the water inlet of the wastewater inlet triple box and the water inlet of the desulfurization wastewater tank; the desulfurization wastewater circulating loop pipe and the desulfurization wastewater self-return pipe are both provided with a desulfurization wastewater flowmeter and a desulfurization wastewater thermometer.

[0010] Preferably, the included angle of the V-shaped guide evaporation groove is greater than or equal to twice the complementary angle of the solar altitude angle on the local winter solstice; each groove in the V-shaped guide evaporation groove is pressed from a whole plate and covers the entire top of the air-cooling island; the top spacing on both sides of the V-shaped guide evaporation groove is greater than the groove body width of the wastewater collecting tank; the bottom of the V-shaped guide evaporation groove is arc-shaped.

[0011] Preferably, the ridge gutter is arranged parallel to and higher than the ridge of the air-cooling island.

[0012] Preferably, the inlet of the steam distribution pipe is connected to the exhaust pipe of the steam turbine, and the cooling triangle downstream tube bundle and the cooling triangle countercurrent tube bundle are both connected to the heat recovery system of the steam turbine through a condensate pump.

[0013] The operation method of the wastewater treatment system for comprehensive utilization of waste heat from air-cooled island and solar energy comprises the following steps:

[0014] Step 1: The desulfurized wastewater is connected to the desulfurized wastewater feed pipe from the outlet of the triple box of the wastewater source and the outlet of the desulfurized wastewater pool, and the desulfurized wastewater is pumped into the top water tank through the desulfurized wastewater feed pump;

[0015] Step 2, the desulfurized wastewater flows by gravity from the top water tank into the ridge water tank arranged parallel to and higher than the ridge of the air-cooling island, and then flows by gravity into the V-shaped diversion evaporation tank, which is parallel to and higher than the cooling triangle downstream tube bundle and the cooling triangle countercurrent tube bundle; the desulfurized wastewater flows downstream and absorbs the heat dissipated by the air-cooling island and the heat from the solar energy;

[0016] Step 3, the desulfurized wastewater after sufficient heat exchange and evaporation in step 2 flows into the wastewater collecting tanks on both sides of the air cooling island;

[0017] Step 4: After heat exchange and evaporation in the wastewater collecting tank, part of the desulfurized wastewater is pumped back to the top water tank by the adjustable tee and the desulfurized wastewater circulating water pump for further heat exchange; the remaining desulfurized wastewater flows back to the desulfurized wastewater circulating loop pipe or the desulfurized wastewater pool through the desulfurized wastewater reflux pipe.

[0018] Preferably, the wastewater from the wastewater route in step 1 enters the triple box into the desulfurization wastewater pool through a pipeline.

[0019] Preferably, the wastewater inlet and outlet of the triplex box, the outlet of the desulfurization wastewater pool, the desulfurization wastewater self-return pipe and the desulfurization wastewater circulation loop pipe in steps 1 and 4 are made of corrosion-resistant materials.

[0020] Preferably, the desulfurization wastewater feed pump in step 1 and the adjustable tee and desulfurization wastewater circulating water pump in step 4 are provided with a spare circuit, which leads to the wastewater inlet triplex box.

[0021] Preferably, in steps 1 to 4:

[0022] The material of the V-shaped guide evaporation trough is 304 or above stainless steel, the trough width of the V-shaped guide evaporation trough is less than or equal to 2 meters, the material thickness is between 2 and 25 mm, and the mechanical fixing method of the V-shaped guide evaporation trough is riveting, bolting or flange connection;

[0023] The material of the ridge gutter is 304 or higher stainless steel, the material thickness is between 2 and 25 mm, the trough width is greater than or equal to 30 cm, the trough depth of the ridge gutter is greater than or equal to 30 cm; the water supply is greater than or equal to 2 t / h;

[0024] The wastewater collecting tank is made of 304 or higher stainless steel, with a material thickness of 2 to 25 mm, a tank width of 30 cm or more, a depth of 30 cm or more, and a capacity greater than the amount of desulfurization wastewater produced in one hour;

[0025] The desulfurization wastewater self-return pipe shall be made of rubber-lined steel pipe or stainless steel of grade 304 or above, with a thickness of 2 to 25 mm and a flow rate of 2 t / h or more;

[0026] The desulfurization wastewater feed pipe, desulfurization wastewater circulation loop pipe, desulfurization wastewater self-return pipe and other water pipes are equipped with insulation layers and are sealed;

[0027] The adjustable tee and desulfurization wastewater circulating water pump are remotely controlled; the pipeline flow connected by the adjustable tee and the desulfurization wastewater circulating water pump is greater than or equal to 1t / h, and rubber-lined steel pipes or stainless steel with grade 304 and above are used, with a thickness between 2 and 25mm.

[0028] The temperature that the wastewater can be raised to in a single day can be calculated:

[0029]

[0030] In the above formula, Q WO is the wastewater input, in kg; c is the specific heat capacity of water, in J / kg*K; η is the heat loss rate, which is taken as 97% to 99%; q is the average turbine return water volume per hour on that day, in kg / h; t is the number of operating hours on that day; r is the latent heat of vaporization of water, in J / kg; δ is the declination angle on a certain date; λ is the latitude of the area; β is the declination angle between the V-shaped diversion evaporation trough and the horizontal direction; ω' SS K is the solar hour angle of the V-shaped diversion evaporation trough at sunset; T is the clearness index of the area; ψ ext is the external radiation intensity of the atmosphere, which is 1350w / m 2 ; A is the total area of ​​the V-shaped evaporation tank, in m 2 .

[0031] The beneficial effects of the present invention are as follows: the present invention provides a method for heating desulfurization wastewater by using solar energy and heat dissipation of an air-cooled island to achieve the effect of concentration and reduction. When the outdoor temperature is high, the direct sunlight on the air-cooled condenser can be reduced, the heat exchange effect of the air-cooled condenser can be increased, and the desulfurization wastewater can be concentrated and reduced at the same time; when the outdoor temperature is low in winter, the desulfurization wastewater can be concentrated and reduced by heat dissipation of the air-cooled island, and reflux can be used to maintain the temperature of the desulfurization wastewater pool, so that it continues to evaporate naturally, and at the same time can help increase the heat exchange effect of the air-cooled condenser. The compact layout without affecting the heat dissipation of the air-cooled island can be applied in the field of wastewater evaporation reduction treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the wastewater treatment system that utilizes waste heat from the air-cooling island and solar energy.

[0033] Explanation of the accompanying drawings: steam distribution pipe 1, axial flow fan 2, cooling triangle downstream tube bundle 3, cooling triangle countercurrent tube bundle 4, wastewater inlet triple box 5, desulfurization wastewater flow meter 6, desulfurization wastewater thermometer 7, desulfurization wastewater feed pipe 8, desulfurization wastewater feed pump 9, top water tank 10, ridge water tank 11, V-shaped diversion evaporation tank 12, wastewater collecting tank 13, adjustable tee and desulfurization wastewater circulating water pump 14, desulfurization wastewater circulating loop pipe 15, desulfurization wastewater self-reflux pipe 16, desulfurization wastewater tank 17. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0035] The air cooling island includes a steam distribution pipe 1, a cooling triangle downstream tube bundle 3, a cooling triangle countercurrent tube bundle 4 and an axial flow fan 2.

[0036] Zhejiang Energy Xinjiang Aksu Power Plant is equipped with two air-cooled 350MW units. After comprehensive utilization, its wastewater eventually becomes high-salt and high-impurity desulfurization wastewater. After the wastewater enters the triple box 5 for treatment, it still has high salt and high corrosiveness. Evaporation and crystallization are the main treatment methods. The Aksu area is hot in summer. Under direct sunlight, the temperature of the air-cooled condenser is much higher than the ambient temperature, affecting the vacuum degree. Although the evaporation rate is high, the wastewater cannot be completely evaporated and consumed when it is turned on. In winter, the wastewater is frozen for a long time and cannot be naturally evaporated and reduced. Since the air-cooled island is usually located at a height of about 30m, if crystallization occurs at high altitude, cleaning and maintenance will become a hassle. Therefore, this device is a heating reduction device for crystallization.

[0037] like Figure 1 As shown in the figure, the evaporation reduction device designed for this power plant is:

[0038] From the outlet of the triple box and the desulfurization wastewater pool 17. Take the desulfurization wastewater to the desulfurization wastewater feed pipe 8, and pump the desulfurization wastewater clean water into the top water tank through the desulfurization wastewater feed pump 9, and then flow by gravity into the ridge water tank 11 arranged parallel to and higher than the ridge of the air-cooling island. Then, it is distributed by gravity into the V-shaped guide evaporation tank 12 arranged parallel to and higher than the cooling triangle downstream tube bundle 3 and the cooling triangle countercurrent tube bundle 4, and flows downstream to absorb the heat dissipation of the air-cooling island and the solar heating. After sufficient heat exchange and evaporation, the desulfurization wastewater flows into the wastewater collecting tank 13 on both sides of the air-cooling island. Under the adjustment of the three-way valve at the outlet of the collecting tank, part of the liquid is pumped back to the top water tank 10 by the circulating loop water pump for heat exchange again, and the remaining part of the liquid flows back by gravity to the desulfurization wastewater pool 17 or the inlet of the triple box 5 from the wastewater source.

[0039] The desulfurization wastewater feed pipe 8 is a φ80mm rubber-lined steel pipe with insulation, and the top water tank 10 has a capacity of 9m 3 . The ridge gutter 11 is made of 304 stainless steel, 3mm thick, 60cm wide, 50cm deep, and rolled from a steel plate. The V-shaped diversion evaporation trough 12 is made of 304 stainless steel, 3mm thick, 1m wide, 110° angle, 2m interval, and each diversion trough is rolled from a steel plate. The liquid collecting troughs on both sides are made of 304 stainless steel, 3mm thick, 50cm wide, 50cm deep, and rolled from a steel plate. The liquid circulation loop is a φ50mm rubber-lined steel pipe with insulation. The gravity return uses a φ80mm rubber-lined steel pipe with insulation.

[0040] An operation method of a wastewater treatment system for comprehensive utilization of waste heat from an air-cooled island and solar energy, including but not limited to the following steps:

[0041] Step 1, the desulfurized wastewater is connected to the desulfurized wastewater feed pipe 8 from the outlet of the wastewater inlet triple box 5 and the outlet of the desulfurized wastewater tank 17, and the desulfurized wastewater is pumped into the top water tank 10 through the desulfurized wastewater feed pump 9;

[0042] Step 2, the desulfurized wastewater flows by gravity from the top water tank 10 into the ridge water tank 11 arranged parallel to and higher than the ridge of the air-cooling island, and then flows by gravity into the V-shaped guide evaporation tank 12, which is parallel to and higher than the cooling triangle downstream tube bundle 3 and the cooling triangle countercurrent tube bundle 4; the desulfurized wastewater flows downstream and absorbs the heat dissipated by the air-cooling island and the heat from the solar energy;

[0043] Step 3, the desulfurized wastewater after sufficient heat exchange and evaporation in step 2 flows into the wastewater collecting tanks 13 on both sides of the air cooling island;

[0044] Step 4, after heat exchange and evaporation in the wastewater collecting tank 13, part of the desulfurized wastewater is pumped back to the top water tank 10 by the adjustable tee and the desulfurized wastewater circulating water pump 14 for further heat exchange; the remaining desulfurized wastewater flows back by gravity through the desulfurized wastewater reflux pipe 16 to the desulfurized wastewater circulation loop pipe 15 or the desulfurized wastewater tank 17.

[0045] The wastewater from the wastewater in step 1 enters the desulfurization wastewater tank 17 through a pipeline.

[0046] The pipelines of the wastewater inlet triple box 5 outlet, the desulfurization wastewater pool 17 outlet, the desulfurization wastewater self-return pipe 16 and the desulfurization wastewater circulation loop pipe 15 described in step 1 and step 4 are made of corrosion-resistant materials.

[0047] The desulfurization wastewater feed pump 9 in step 1 and the adjustable tee and desulfurization wastewater circulating water pump 14 in step 4 are equipped with a spare circuit, which leads to the wastewater inlet triple box 5.

[0048] In steps 1 to 4:

[0049] The material of the V-shaped guide evaporation trough 12 is 304 or higher stainless steel, the trough width of the V-shaped guide evaporation trough 12 is less than or equal to 2 meters, the material thickness is between 2 and 25 mm, and the mechanical fixing method of the V-shaped guide evaporation trough 12 is riveting, bolting or flange connection;

[0050] The material of the ridge gutter 11 is 304 or higher stainless steel, the material thickness is between 2 and 25 mm, the gutter width is greater than or equal to 30 cm, and the gutter depth of the ridge gutter 11 is greater than or equal to 30 cm; the water supply is greater than or equal to 2 t / h;

[0051] The wastewater collecting tank 13 is made of 304 or higher stainless steel, with a material thickness of 2 to 25 mm, a tank width of 30 cm or more, a depth of 30 cm or more, and a capacity greater than the amount of desulfurization wastewater produced in one hour;

[0052] The desulfurization wastewater self-return pipe 16 is made of rubber-lined steel pipe or stainless steel of grade 304 or above, with a thickness of 2 to 25 mm and a flow rate greater than or equal to 2 t / h;

[0053] The desulfurization wastewater feed pipe 8, the desulfurization wastewater circulation loop pipe 15, the desulfurization wastewater self-return pipe 16 and other upper and lower water pipes are equipped with insulation layers and are sealed;

[0054] The adjustable tee and the desulfurization wastewater circulating water pump 14 are remotely controlled; the flow rate of the pipeline connected by the adjustable tee and the desulfurization wastewater circulating water pump 14 is greater than or equal to 1t / h, and rubber-lined steel pipes or stainless steel with grade 304 or above are selected, with a thickness between 2 and 25mm.

[0055] The temperature that the wastewater can be raised to in a single day can be calculated:

[0056]

[0057] In the above formula, Q WO is the wastewater input, in kg; c is the specific heat capacity of water, in J / kg*K; η is the heat loss rate, which is taken as 97% to 99%; q is the average turbine return water volume per hour on that day, in kg / h; t is the number of operating hours on that day; r is the latent heat of vaporization of water, in J / kg; δ is the declination angle on a certain date; λ is the latitude of the area; β is the declination angle between the V-shaped diversion evaporation tank 12 and the horizontal direction; ω' SS K is the solar hour angle of the V-shaped diversion evaporation trough at sunset on the 12th day; T is the clearness index of the area; ψ ext is the external radiation intensity of the atmosphere, which is 1350w / m 2 ; A is the total area of ​​the V-shaped evaporation tank, in m 2 .

[0058] In summer, when the outdoor temperature is high, the direct sunlight on the air-cooled condenser is reduced, the heat exchange effect of the air-cooled condenser is increased, and the desulfurization wastewater is heated by using solar energy and heat dissipation of the air-cooled condenser to achieve the effect of concentration and reduction. In winter, the desulfurization wastewater can be concentrated and reduced by using air-cooled island heat dissipation, and refluxed to maintain the temperature of the desulfurization wastewater pool, so that it continues to evaporate naturally, and at the same time can help increase the environmental humidity, which has positive significance for the surrounding environment.

[0059] The evaporator design can effectively improve the evaporation efficiency of a single distiller, utilize the waste heat from the air-cooling island, reduce the surface vapor pressure of desulfurization wastewater, make full use of solar energy while minimizing the obstruction of rising air from the air-cooling island, achieve a more compact layout, and improve the overall area utilization efficiency. It is applied to the field of desulfurization wastewater treatment by waste heat evaporation from air-cooling islands. The circulation system behind the liquid collection tank can reduce the energy consumption of the electric pump to overcome the potential energy of the wastewater, which is beneficial to the heat absorption and evaporation of the wastewater. The desulfurization wastewater is heated and then returned to the desulfurization wastewater pool, which can keep the wastewater in the pool from freezing in winter and maintain the system circulation operation and natural evaporation.

Claims

1. An operation method of a wastewater treatment system for comprehensive utilization of waste heat from an air-cooled island and solar energy, characterized in that: A wastewater treatment system for comprehensive utilization of waste heat from an air-cooling island and solar energy comprises: a steam distribution pipe (1), an axial flow fan (2), a cooling triangle downstream tube bundle (3), a cooling triangle countercurrent tube bundle (4), a wastewater inlet triple box (5), a desulfurization wastewater flow meter (6), a desulfurization wastewater thermometer (7), a desulfurization wastewater feed pipe (8), a desulfurization wastewater feed pump (9), a top water tank (10), a ridge water tank (11), a V-shaped diversion evaporation tank (12), a wastewater collecting tank (13), an adjustable three-way and a desulfurization wastewater circulating water pump (14), a desulfurization wastewater circulating loop pipe (15), a desulfurization wastewater self-return pipe (16) and a desulfurization wastewater pool (17); the cooling triangle The downstream tube bundle (3), the cooling triangle countercurrent tube bundle (4) and the steam distribution pipe (1) are connected and meet at the outlet of the steam distribution pipe (1); the cooling triangle downstream tube bundle (3) and the cooling triangle countercurrent tube bundle (4) are opened to a certain angle directly downward and are in a ridge-like inverted V shape as a whole; the axial flow fan (2) is arranged directly below the outlet of the steam distribution pipe (1); the wastewater inlet triple box (5) and the bottom outlet of the desulfurization wastewater pool (17) are both connected to the inlet of the desulfurization wastewater feed pump (9) through a pipeline, the outlet of the desulfurization wastewater feed pump (9) is connected to one end of the desulfurization wastewater feed pipe (8), and the other end of the desulfurization wastewater feed pipe (8) is connected to the water inlet of the top water tank (10) ; A desulfurization wastewater flowmeter (6) and a desulfurization wastewater thermometer (7) are provided on the desulfurization wastewater feed pipe (8); the outlet of the top water tank (10) is connected to the inlet of the roof ridge water tank (11), and the outlets at both ends of the roof ridge water tank (11) are respectively connected to the two starting ends of the V-shaped guide evaporation tank (12), the V-shaped guide evaporation tank (12) takes the roof ridge of the air-cooling island as the symmetry axis, and is parallel to and higher than the cooling triangle downstream tube bundle (3) and the cooling triangle countercurrent tube bundle (4); wastewater collecting tanks (13) are respectively provided directly below the ends of both sides of the V-shaped guide evaporation tank (12); the outlets of the two wastewater collecting tanks (13) are connected to an adjustable tee and a desulfurization wastewater circulating water pump (14 ) inlet; the adjustable tee and the outlet of the desulfurization wastewater circulating water pump (14) are divided into two paths: one path is connected to one end of the desulfurization wastewater circulating loop pipe (15), and the other end of the desulfurization wastewater circulating loop pipe (15) is connected to the water inlet of the top water tank (10); the other path is connected to one end of the desulfurization wastewater self-return pipe (16), and the other end of the desulfurization wastewater self-return pipe (16) is connected to the water inlet of the wastewater inlet triple box (5) and the water inlet of the desulfurization wastewater pool (17); the desulfurization wastewater circulating loop pipe (15) and the desulfurization wastewater self-return pipe (16) are both provided with a desulfurization wastewater flowmeter (6) and a desulfurization wastewater thermometer (7); the operation method comprises the following steps: Step 1, the desulfurized wastewater is connected to the desulfurized wastewater feed pipe (8) from the outlet of the wastewater inlet triple box (5) and the outlet of the desulfurized wastewater pool (17), and the desulfurized wastewater is pumped into the top water tank (10) through the desulfurized wastewater feed pump (9); Step 2, the desulfurized wastewater flows by gravity from the top water tank (10) into the ridge water tank (11) arranged parallel to and higher than the ridge of the air-cooling island, and then flows by gravity into the V-shaped guide evaporation tank (12), which is parallel to and higher than the cooling triangle downstream tube bundle (3) and the cooling triangle countercurrent tube bundle (4); the desulfurized wastewater flows downstream and absorbs heat from the air-cooling island and solar energy; Step 3, the desulfurized wastewater after sufficient heat exchange and evaporation in step 2 flows into the wastewater collecting tanks (13) on both sides of the air cooling island; Step 4: After heat exchange and evaporation in the wastewater collecting tank (13), part of the desulfurized wastewater is pumped back to the top water tank (10) by the adjustable three-way valve and the desulfurized wastewater circulating water pump (14) for further heat exchange; the remaining desulfurized wastewater flows back by gravity through the desulfurized wastewater self-return pipe (16) to the desulfurized wastewater circulation loop pipe (15) or the desulfurized wastewater tank (17); Calculate the temperature of wastewater raised in a single day and conduct wastewater scheduling throughout the year. The calculation formula for the temperature of wastewater raised in a single day is: In the above formula, Q WO is the wastewater input, in kg; c is the specific heat capacity of water, in J / kg*K; η is the heat loss rate, which is taken as 97% to 99%; q is the average turbine return water volume per hour on that day, in kg / h; t is the number of operating hours on that day; r is the latent heat of vaporization of water, in J / kg; δ is the declination angle on a certain date; λ is the latitude of the region; β is the declination angle between the V-shaped guide evaporation trough (12) and the horizontal direction; ω′ SS K is the solar hour angle of the V-shaped diversion evaporation trough (12) at sunset; T is the clearness index of the area; ψ ext is the external radiation intensity of the atmosphere, which is 1350w / m 2 ; A is the total area of ​​the V-shaped guide evaporation groove (12), in m 2 .

2. The operation method of the wastewater treatment system for comprehensive utilization of waste heat from air-cooled island and solar energy according to claim 1 is characterized by: The wastewater from the wastewater route in step 1 enters the triple box (5) through a pipeline and enters the desulfurization wastewater tank (17).

3. The operation method of the wastewater treatment system for comprehensive utilization of waste heat from air-cooled island and solar energy according to claim 1 is characterized by: In step 1 and step 4, the pipes of the wastewater inlet triple box (5) outlet, the desulfurization wastewater pool (17) outlet, the desulfurization wastewater self-return pipe (16) and the desulfurization wastewater circulation loop pipe (15) are made of corrosion-resistant materials.

4. The operating method of the wastewater treatment system for comprehensive utilization of waste heat from air-cooled island and solar energy according to claim 1 is characterized by: The desulfurization wastewater feed pump (9) in step 1 and the adjustable tee and desulfurization wastewater circulating water pump (14) in step 4 are equipped with a spare circuit, which leads to the wastewater inlet triple box (5).

5. The operation method of the wastewater treatment system for comprehensive utilization of waste heat from air-cooled island and solar energy according to claim 1 is characterized in that: In steps 1 to 4: The material of the V-shaped guide evaporation groove (12) is stainless steel, the groove width of the V-shaped guide evaporation groove (12) is less than or equal to 2 meters, the material thickness is between 2 and 25 mm, and the mechanical fixing method of the V-shaped guide evaporation groove (12) is riveting, bolt connection or flange connection; The ridge gutter (11) is made of stainless steel, the material thickness is between 2 and 25 mm, the gutter width is greater than or equal to 30 cm, and the gutter depth is greater than or equal to 30 cm; the water supply is greater than or equal to 2 t / h; The wastewater collecting tank (13) is made of stainless steel, with a material thickness of 2 to 25 mm, a tank body width of 30 cm or more, a depth of 30 cm or more, and a capacity greater than the amount of desulfurization wastewater produced in one hour; The desulfurization wastewater self-return pipe (16) is made of rubber-lined steel pipe or stainless steel, with a thickness of 2 to 25 mm and a flow rate greater than or equal to 2 t / h; The desulfurization wastewater feed pipe (8), the desulfurization wastewater circulation loop pipe (15), the desulfurization wastewater self-return pipe (16) and other upper and lower water pipes are equipped with insulation layers and are sealed; The adjustable tee and the desulfurization wastewater circulating water pump (14) are remotely controlled; the flow rate of the pipeline connected to the adjustable tee and the desulfurization wastewater circulating water pump (14) is greater than or equal to 1t / h, and a rubber-lined steel pipe or stainless steel pipe is selected with a thickness between 2 and 25mm.

6. The operation method of the wastewater treatment system for comprehensive utilization of waste heat from air-cooled island and solar energy according to claim 1 is characterized in that: The included angle of the V-shaped guide evaporation groove (12) is greater than or equal to twice the complementary angle of the solar altitude angle on the local winter solstice; each groove in the V-shaped guide evaporation groove (12) is pressed from a whole plate and covers the entire top of the air-cooling island; the top spacing on both sides of the V-shaped guide evaporation groove (12) is greater than the groove body width of the wastewater collecting groove (13); and the bottom of the V-shaped guide evaporation groove (12) is arc-shaped.

7. The operation method of the wastewater treatment system for comprehensive utilization of waste heat from air-cooled island and solar energy according to claim 1 is characterized in that: The inlet of the steam distribution pipe (1) is connected to the exhaust pipe of the steam turbine, and the cooling triangle downstream tube bundle (3) and the cooling triangle reverse flow tube bundle (4) are both connected to the heat recovery system of the steam turbine through a condensate pump.

Images