A system and method for deep recycling of urban reclaimed water as industrial water for thermal power plants

Abstract

The present invention relates to a system for deep reuse of urban reclaimed water as industrial water for thermal power plants, comprising: an ABFT biochemical treatment pool, an intermediate water pool, a muddy water well, an accelerated clarification pool, a clean water well, a circulating water system, a cooling tower, a cold water pump, an industrial miscellaneous water pipeline, an ultraviolet disinfection pool, a filter A, an ultrafiltration system, a reverse osmosis system, a yin-yang mixed bed, a desalted water tank, a boiler steam-water system, water treatment regeneration equipment, a hydrogen station, a chemical laboratory, a fine treatment regeneration wastewater tank, a stripping and distillation denitrification device, a chemical regeneration wastewater tank, a filter B, a nanofiltration device, a power plant desulfurization wastewater pool, an electrodialysis system and a drying tower. The beneficial effects of the present invention are: an ABFT water purification system is provided, which has strong adaptability, large load capacity, and can purify and maintain dominant bacterial flora; the outlet pipeline of the clean water well is used to deeply treat the water quality and replenish water to the boiler steam-water system; an ultraviolet disinfection pool is provided to remove bacteria and organic matter in the water and reduce TOC.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to a system and method for deep recycling of urban reclaimed water as industrial water for thermal power plants. Background Art

[0002] In recent years, with the acceleration of the country's industrialization and urbanization, the national electricity consumption has continued to rise. At present, the main power generation method in my country is still thermal power generation, which accounts for more than 70% of my country's total power generation. The method of generating electricity using the energy contained in combustibles is collectively referred to as thermal power generation. According to the power generation method, thermal power generation is divided into coal-fired steam turbine power generation and oil-fired steam turbine power generation. Thermal power plants need to consume a large amount of water resources to maintain normal production needs. There are differences in the distribution of water resources in the north and south of my country. The south is rich in water resources. The industrial water used by thermal power plants is mostly taken from surface water such as rivers, lakes, etc., but due to the large daily water intake, it still brings a huge burden to the natural environment; the northern region is short of water resources. Thermal power plants built in water-scarce areas in the north mostly introduce treated reclaimed water from municipal sewage treatment plants as industrial water sources.

[0003] Most of the industrial water used in thermal power plants is used in circulating water systems, which have relatively low requirements for water quality. In the existing reclaimed water reuse technology, the reclaimed water discharged from the sewage treatment plant after upgrading can be directly used for cooling tower water replenishment after conventional treatment. However, the boiler steam water system replenishment water, which has extremely stringent requirements on water quality, is still mostly taken from surface water, groundwater or desalted water after seawater desalination. Not only is the water extraction cost high, but the treatment process is cumbersome and the equipment maintenance cost is also quite high.

[0004] The aerated biological fluidized tank (ABFT) sewage process is a new sewage treatment technology for biochemical removal of ammonia nitrogen in recent years. The ABFT reactor is actually a dual bioreactor that combines the advantages of the traditional activated sludge method and the biofilm method. In each level of ABFT reactor, the degradation effect of the target pollutants is improved by cultivating different special and advantageous strains; the biomass grown by the carrier can reach up to 10g / L~18g / L. The combination of the microorganisms and the carrier after survival adopts the immobilization technology of bond valence, so the binding force is strong, not easy to fall off, and not easy to lose. The high-load biomass ensures the efficiency and stability of the ABFT reactor in removing pollutants. Ultraviolet sterilization uses ultraviolet light below 200nm emitted by high-energy ultraviolet lamps to cause water to undergo photolysis and produce extremely high-energy hydroxyl free radicals. These hydroxyl free radicals can react with organic compounds. Ultraviolet light irradiation to remove organic matter can control the effluent TOC at a very low level.

[0005] Electrodialysis is a relatively mature technology in the membrane separation process and has been widely used in the desalination of brackish water. Because the newly developed charged membrane has higher selectivity, lower membrane resistance, better chemical stability and higher mechanical strength, electrodialysis technology can be used in the reduction of desulfurization wastewater in power plants with poor water quality.

[0006] Nanofiltration (NF) separation is a green water treatment technology that can replace traditional wastewater treatment methods that are expensive and cumbersome in some aspects. Nanofiltration membranes can intercept organic matter with a molecular weight greater than 100 and multivalent ions through their own unique properties, and only allow small molecular organic matter and monovalent ions to pass through.

[0007] In order to make the industrial water system of the power plant have good environmental and economic benefits and comply with the national water conservation and environmental protection policies, a greener and more economical water extraction method is needed to meet the needs of industrial production. Summary of the invention

[0008] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a system and method for deep recycling of urban water as industrial water for thermal power plants.

[0009] This system for deep reuse of urban reclaimed water for industrial water use in thermal power plants includes: ABFT biochemical treatment pool, intermediate water pool, muddy water well, accelerated clarification pool, clear water well, circulating water system, cooling tower, cold water pump, industrial miscellaneous water pipeline, ultraviolet disinfection pool, filter A, ultrafiltration system, reverse osmosis system, yin and yang mixed bed, desalted water tank, boiler steam water system, water treatment regeneration equipment, hydrogen station, chemical laboratory, fine treatment regeneration wastewater tank, steam stripping and distillation denitrification device, chemical regeneration wastewater tank, filter B, nanofiltration device, power plant desulfurization wastewater pool, electrodialysis system and drying tower;

[0010] The inlet pipe of the ABFT biochemical treatment pool is connected to the outlet pipe of the sewage treatment plant, the outlet pipe of the ABFT biochemical treatment pool is connected to the inlet pipe of the intermediate water pool, the outlet pipe of the intermediate water pool is connected to the inlet pipe of the muddy water well, the outlet pipe of the muddy water well is connected to the inlet pipe of the accelerated clarification pool, and the outlet pipe of the accelerated clarification pool is connected to the inlet pipe of the clean water well; the outlet pipe of the clean water well is divided into two routes, one of which is connected to the inlet pipe of the circulating water system, and the other is connected to the inlet pipe of the ultraviolet disinfection pool; the outlet pipe of the circulating water system The pipeline is divided into three routes, which are respectively connected to the water inlet pipeline of the cooling tower, the cold water pump pipeline and the industrial miscellaneous water pipeline; the outlet pipeline of the ultraviolet disinfection pool is connected to the water inlet pipeline of the filter A, the outlet pipeline of the filter A is connected to the water inlet pipeline of the ultrafiltration system, and the outlet pipeline of the ultrafiltration system is connected to the water inlet pipeline of the reverse osmosis system; the outlet pipeline of the reverse osmosis system is divided into two routes, which are respectively connected to the water inlet pipeline of the yin-yang mixed bed and the water inlet pipeline of the ABFT biochemical treatment pool; the outlet pipeline of the yin-yang mixed bed is divided into two routes, which are respectively connected to the water inlet pipeline of the chemical regeneration wastewater tank and the water inlet pipeline of the desalted water tank;

[0011] The outlet pipe of the desalted water tank is divided into four routes, which are respectively connected to the water inlet pipe of the chemical laboratory, the water inlet pipe of the hydrogen station, the water inlet pipe of the water treatment regeneration equipment and the water inlet pipe of the boiler steam-water system; the outlet pipe of the boiler steam-water system is connected to the water inlet pipe of the fine treatment regeneration wastewater tank, the outlet pipe of the fine treatment regeneration wastewater tank is connected to the water inlet pipe of the steam stripping and distillation denitrification device, and the outlet pipe of the denitrification device is connected to the water inlet pipe; the outlet pipe of the chemical regeneration wastewater tank is connected to the water inlet pipe of the filter B, and the outlet pipe of the filter B is connected to the water inlet pipe of the nanofiltration device; the outlet pipe of the nanofiltration device is connected to the water inlet pipe of the drying tower;

[0012] The outlet pipe of the desulfurization wastewater pool of the power plant is connected to the inlet pipe of the electrodialysis system, and the outlet pipe of the electrodialysis system is connected to the water inlet pipe of the drying tower.

[0013] Preferably, the interior of the ABFT biochemical treatment pool is divided into a decarbonization zone, a high-speed nitrification zone, a medium-speed nitrification zone and a low-speed nitrification zone; the wastewater in the ABFT biochemical treatment pool first passes through the decarbonization zone, then passes through the high-speed nitrification zone, then enters the medium-speed nitrification zone, and finally flows through the low-speed nitrification zone.

[0014] Preferably, a blower is also provided in the biochemical treatment pool.

[0015] Preferably, the intermediate water tank is connected to the muddy water well through a centrifugal pump, and the muddy water well is also provided with a matching coagulant dosing device.

[0016] Preferably, a processing and digestion module is also provided in the boiler steam-water system.

[0017] The working method of the system for deep recycling of urban water for industrial water use in thermal power plants specifically includes the following steps:

[0018] Step 1, the effluent from the sewage treatment plant is transported to the ABFT biochemical treatment pool in the power plant through a lifting water pump and a pipeline system, and is biochemically treated through the decarbonization zone, high-speed nitrification zone, medium-speed nitrification zone, and low-speed nitrification zone of the ABFT biochemical treatment pool; the effluent from the ABFT biochemical treatment pool is lifted to the muddy water well by a centrifugal pump through the intermediate water pool, and the coagulant dosing device supporting the muddy water well is used to add the agent, and the effluent from the muddy water well flows into the mechanical accelerated clarification tank by gravity for sedimentation treatment, and the clean water after the sedimentation treatment flows into the clean water well;

[0019] Step 2, one outlet water of the clean water well is reused in the circulating water system, which mainly provides water for the cooling tower. The outlet water also supplies the cooling water pump and industrial miscellaneous water; the other outlet water of the clean water well is firstly subjected to deep treatment of water quality, and then used for water replenishment of the boiler steam water system, enters the ultraviolet disinfection pool, removes bacteria and organic matter in the water and reduces TOC after ultraviolet disinfection, and then filters out suspended particles through filter A, and enters the ultrafiltration system after being pressurized by the booster pump to remove large molecular particles in the water, and then pressurized again to enter the reverse osmosis system, so that the outlet water desalination rate reaches more than 98%, and the reverse osmosis concentrated water generated in the reverse osmosis system is returned to the ABFT biochemical treatment pool for treatment, and the other water produced by the reverse osmosis system is lifted by a centrifugal pump and enters the yin-yang mixed bed (enters the yang bed, the anion bed and the mixed bed in turn) for further desalination, so that the final water quality meets the desalted water standard specified in GB / T 12145-2016; the outlet water of the yin-yang mixed bed enters the desalted water tank and the chemical regeneration wastewater tank;

[0020] Step 3, the desalted water tank mainly supplies water for the boiler steam-water system, and the desalted water tank also supplies water to the water treatment regeneration equipment, hydrogen station and chemical laboratory; the refined regeneration wastewater obtained by the boiler steam-water system through the treatment digestion module flows into the refined regeneration wastewater tank, and the refined regeneration wastewater contains a large amount of NH3-N; the refined regeneration wastewater in the refined regeneration wastewater tank is denitrified by the steam stripping and distillation denitrification device, and then combined with the chemical regeneration wastewater after the insoluble matter in the chemical regeneration wastewater tank is filtered out by filter B, and then pressurized by the booster pump and enters the nanofiltration device for classification;

[0021] Step 4: After the desulfurization wastewater in the power plant desulfurization wastewater pool is concentrated and reduced by the electrodialysis system, it is combined with the effluent from the nanofiltration device and enters the drying tower. In the drying tower, the terminal wastewater is evaporated by the bypass flue evaporation technology, and the remaining ash is collected and transported out.

[0022] Preferably, when the biochemical treatment is carried out in the ABFT biochemical treatment tank in step 1: an appropriate blower is used to deliver oxygen required for the biochemical process into the decarbonization zone, high-speed nitrification zone, medium-speed nitrification zone and low-speed nitrification zone in the biochemical treatment tank, and under the action of microorganisms and nitrifying bacteria in the sewage, various pollutants in the sewage are degraded, especially ammonia nitrogen in the water is effectively removed through nitrification.

[0023] Preferably, in step 1, the effluent from the sewage treatment plant is transported to the ABFT biochemical treatment pool in the power plant through a lifting pump and a pipeline system.

[0024] The beneficial effects of the present invention are:

[0025] The present invention provides a system for deep recycling of urban reclaimed water as industrial water for thermal power plants. The system creatively introduces the reclaimed water discharged from the sewage treatment plant into the plant area for treatment, and uses part of it in the circulating water system, while the other part is further used for boiler steam-water system replenishment after deep treatment. At the same time, the wastewater generated during the operation of the system is concentrated and reduced in volume and then evaporated in a drying tower for treatment, so that no wastewater is discharged.

[0026] In the present invention, the industrial water of the thermal power plant is taken from the treated water source of the sewage treatment plant, realizing zero surface water extraction. The ABFT process is applied to the treatment of reclaimed water, so that the effluent meets the water demand of the plant's circulating water system, and the effluent can meet the water quality requirements of the boiler steam-water system after deep treatment.

[0027] The present invention applies ultraviolet disinfection and sterilization technology to the water treatment process of thermal power plants for the first time, replacing the traditional chemical dosing method, effectively avoiding the introduction of toxic substances and the damage of residual chlorine to subsequent membrane components, reducing environmental pollution while also saving costs.

[0028] The present invention collects the terminal wastewater generated during the operation, including chemical regeneration wastewater, fine treatment regeneration wastewater and desulfurization wastewater after concentration and reduction, and sends them to the bypass flue drying system for evaporation. The remaining ash containing salt and other substances is centrally exported, and the waste heat of flue gas is used to effectively solve the treatment problem of such wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a process flow chart of the present invention.

[0030] Explanation of the reference numerals: sewage treatment plant 1, ABFT biochemical treatment tank 2, intermediate water tank 3, muddy water well 4, accelerated clarification tank 5, clean water well 6, circulating water system 7, cooling tower 71, cold water pump pipeline 72, industrial miscellaneous water pipeline 73, ultraviolet disinfection tank 8, filter A9, ultrafiltration system 10, reverse osmosis system 11, yin and yang mixed bed 12, desalted water tank 13, boiler steam and water system 131, water treatment regeneration equipment 132, hydrogen station 133, chemical laboratory 134, fine treatment regeneration wastewater tank 14, steam stripping and distillation denitrification device 15, chemical regeneration wastewater tank 16, filter B17, nanofiltration device 18, power plant desulfurization wastewater tank 19, electrodialysis system 20, drying tower 21. DETAILED DESCRIPTION

[0031] 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.

[0032] Embodiment 1:

[0033] like Figure 1 As shown, a system for deep reuse of urban reclaimed water as industrial water for thermal power plants includes: ABFT biochemical treatment pool 2, intermediate water pool 3, muddy water well 4, accelerated clarification pool 5, clean water well 6, circulating water system 7, cooling tower 71, cold water pump 72, industrial miscellaneous water pipeline 73, ultraviolet disinfection pool 8, filter A9, ultrafiltration system 10, reverse osmosis system 11, yin and yang mixed bed 12, demineralized water tank 13, boiler steam water system 131, water treatment regeneration equipment 132, hydrogen station 133, chemical laboratory 134, fine treatment regeneration wastewater tank 14, stripping and distillation denitrification device 15, chemical regeneration wastewater tank 16, filter B17, nanofiltration device 18, power plant desulfurization wastewater pool 19, electrodialysis system 20 and drying tower 21;

[0034] The inlet pipe of the ABFT biochemical treatment pool 2 is connected to the outlet pipe of the sewage treatment plant 1, the outlet pipe of the ABFT biochemical treatment pool 2 is connected to the inlet pipe of the intermediate water pool 3, the outlet pipe of the intermediate water pool 3 is connected to the inlet pipe of the muddy water well 4, the outlet pipe of the muddy water well 4 is connected to the inlet pipe of the accelerated clarification pool 5, and the outlet pipe of the accelerated clarification pool 5 is connected to the inlet pipe of the clean water well 6; the outlet pipe of the clean water well 6 is divided into two routes, one of which is connected to the inlet pipe of the circulating water system 7, and the other is connected to the inlet pipe of the ultraviolet disinfection pool 8; the outlet pipe of the circulating water system 7 is divided into three routes, which are respectively connected to the inlet pipe of the cooling tower 71, the cold water pump pipe 72 and the industrial miscellaneous water pipe 73; the outlet pipe of the ultraviolet disinfection pool 8 The water inlet pipe of the filter A9 is connected to the water inlet pipe of the ultrafiltration system 10, and the water outlet pipe of the ultrafiltration system 10 is connected to the water inlet pipe of the reverse osmosis system 11; the water outlet pipe of the reverse osmosis system 11 is divided into two ways, which are respectively connected to the water inlet pipe of the yin-yang mixed bed 12 and the water inlet pipe of the ABFT biochemical treatment tank 2; the water outlet pipe of the yin-yang mixed bed 12 is divided into two ways, which are respectively connected to the water inlet pipe of the chemical regeneration wastewater tank 16 and the water inlet pipe of the desalted water tank 13; the interior of the ABFT biochemical treatment tank 2 is divided into a decarbonization zone, a high-speed nitrification zone, a medium-speed nitrification zone and a low-speed nitrification zone; a blower is also provided in the biochemical treatment tank 2; the intermediate water tank 3 is connected to the muddy water well 4 through a centrifugal pump, and the muddy water well 4 is also provided with a matching coagulant dosing device;

[0035] The outlet pipe of the desalted water tank 13 is divided into four routes, which are respectively connected to the water inlet pipe of the chemical laboratory 134, the water inlet pipe of the hydrogen station 133, the water inlet pipe of the water treatment regeneration equipment 132 and the water inlet pipe of the boiler steam-water system 131; the outlet pipe of the boiler steam-water system 131 is connected to the water inlet pipe of the fine treatment regeneration wastewater tank 14, the water outlet pipe of the fine treatment regeneration wastewater tank 14 is connected to the water inlet pipe of the steam stripping and distillation denitrification device 15, and the water outlet pipe of the denitrification device 15 is connected to the water inlet pipe of 18; the outlet pipe of the chemical regeneration wastewater tank 16 is connected to the water inlet pipe of the filter B17, and the water outlet pipe of the filter B17 is connected to the water inlet pipe of the nanofiltration device 18; the outlet pipe of the nanofiltration device 18 is connected to the water inlet pipe of the drying tower 21; the boiler steam-water system 131 is also provided with a processing and digestion module;

[0036] The outlet pipe of the power plant desulfurization wastewater pool 19 is connected to the inlet pipe of the electrodialysis system 20 , and the outlet pipe of the electrodialysis system 20 is connected to the water inlet pipe of the drying tower 21 .

[0037] Embodiment 2:

[0038] In the deep treatment and comprehensive utilization project of urban reclaimed water, the ABFT process has the advantages of high removal rate, short biochemical reaction time, strong resistance to NH3-N load hydraulic shock, and low operating cost. The effluent stability is better than the various index requirements of reclaimed water reuse.

[0039] The water from the sewage treatment plant 1 is directly introduced into the ABFT biochemical treatment pool 2 for denitrification. The effluent passes through the intermediate water pool 3, the muddy water well 4, the accelerated clarification pool 5, and finally reaches the clean water well 6. Flocculants and coagulants are added between the muddy water well 4 and the accelerated clarification pool 5. The effluent from the clean water well 6 is mainly supplied to the power plant circulating water system 7, and the water source includes the cooling tower 71, the cold water pump pipeline 72 and the industrial miscellaneous water pipeline 73. The remaining effluent from the clean water well 6 is used to supply the chemical water production process. First, it is ultraviolet disinfected in the ultraviolet disinfection pool 8, and then passes through the filter A9, the ultrafiltration (UF) system 10, the reverse osmosis (RO) system 11, and the yin and yang mixed bed 12 to enter the desalted water tank 13; the water source of the desalted water tank 13 includes the boiler steam water system 131, the water treatment equipment regeneration 132, the hydrogen station 133 and the chemical laboratory 134, and the reverse osmosis RO concentrated water is transported back to the ABFT biochemical treatment pool 2 for treatment.

[0040] The refined regeneration wastewater generated in the boiler steam-water system 131 is stored in the refined regeneration wastewater tank 14, and the chemical regeneration wastewater generated in the chemical water production process is stored in the chemical regeneration wastewater tank 16. The refined regeneration wastewater after denitrification by steam stripping and distillation in the denitrification device 15 is combined with the chemical regeneration wastewater after insoluble matter is filtered out by the filter B17, and then pressurized by the booster pump and enters the nanofiltration device 18 for classification. The desulfurization wastewater in the power plant desulfurization wastewater pool 19 is concentrated and reduced by the electrodialysis system 20, and then combined with the effluent of the nanofiltration system and enters the drying tower 21. In the drying tower 21, the terminal wastewater is evaporated by the bypass flue evaporation technology, and the remaining ash is collected and transported out.

[0041] The city's deep water reuse system has been successfully put into operation and applied to a thermal power plant in the south. The water use situation of a thermal power plant in the south after adopting the system (deep water reuse system) of the city's deep water reuse as industrial water for the thermal power plant is shown in Table 1 below:

[0042] Table 1 Water use conditions of a thermal power plant in the south after using the deep water reuse system of Example 1

[0043]

[0044]

[0045] The plant has signed an agreement with the local sewage treatment plant, and the total water intake is 2128.7t / h.

[0046] The municipal sewage that meets the discharge standards is directly introduced into the plant area and enters the ABFT water purification system. The system uses a new type of biological carrier synthesized from NC-5ppi polymer materials and nitrobacteria-II high-efficiency broad-spectrum dominant nitrifying bacteria. This combination has the advantages of strong adaptability, large load capacity, and the ability to purify and maintain dominant bacterial flora. PAC is added to the pipe mixer connecting the intermediate water tank to the muddy water well, and PAM is added to the muddy water well for coagulation. The ultrafiltration membrane component adopts Asahi Kasei UNA-620A type, and the reverse osmosis membrane component adopts Dow BW30FR-400 / 34 type. Effluent water quality indicators: the average concentration of NH3-N is 0.35mg / L, which is lower than the 1mg / L required by the power plant water quality; the average concentration of CODcr is 19.6mg / L, which is lower than the 60mg / L required by the power plant water quality. The treatment capacity of the first phase of ABFT project is 1060.4t / h, and the treatment capacity of the second phase is 1068.3t / h. The amount of water added to the cooling tower in the circulating cooling water system is 1175t / h, the amount of water added to the cold water system is 418t / h, and the amount of water used for industrial miscellaneous water is 323.3t / h. The amount of water used for boiler steam water in the desalted water tank is 190.5t / h, and the amount of water used for fine treatment regeneration water is 5t / h. The total amount of chemical regeneration wastewater and fine treatment regeneration wastewater is 14.5t / h. The total amount of terminal wastewater treated by flue evaporation technology is 7.5t / h.

Claims

1. A system for deep recycling of urban water as industrial water for thermal power plants, characterized in that: include: ABFT biochemical treatment tank (2), intermediate water tank (3), muddy water well (4), accelerated clarification tank (5), clear water well (6), circulating water system (7), cooling tower (71), cold water pump pipeline (72), industrial miscellaneous water pipeline (73), ultraviolet disinfection tank (8), filter A (9), ultrafiltration system (10), reverse osmosis system (11), yin and yang mixed bed (12), desalted water tank (13), boiler steam water system (131), water treatment regeneration equipment (132), hydrogen station (133), chemical laboratory (134), fine treatment regeneration wastewater tank (14), steam stripping and distillation denitrification device (15), chemical regeneration wastewater tank (16), filter B (17), nanofiltration device (18), power plant desulfurization wastewater tank (19), electrodialysis system (20) and drying tower (21); The inlet pipe of the ABFT biochemical treatment pool (2) is connected to the outlet pipe of the sewage treatment plant (1), the outlet pipe of the ABFT biochemical treatment pool (2) is connected to the inlet pipe of the intermediate water pool (3), the outlet pipe of the intermediate water pool (3) is connected to the inlet pipe of the muddy water well (4), the outlet pipe of the muddy water well (4) is connected to the inlet pipe of the accelerated clarification pool (5), and the outlet pipe of the accelerated clarification pool (5) is connected to the inlet pipe of the clean water well (6); the outlet pipe of the clean water well (6) is divided into two routes, one of which is connected to the inlet pipe of the circulating water system (7), and the other is connected to the inlet pipe of the ultraviolet disinfection pool (8); the outlet pipe of the circulating water system (7) is divided into three routes, The water inlet pipe of the cooling tower (71), the cold water pump pipe (72) and the industrial miscellaneous water pipe (73) are connected; the water outlet pipe of the ultraviolet disinfection pool (8) is connected to the water inlet pipe of the filter A (9), the water outlet pipe of the filter A (9) is connected to the water inlet pipe of the ultrafiltration system (10), and the water outlet pipe of the ultrafiltration system (10) is connected to the water inlet pipe of the reverse osmosis system (11); the water outlet pipe of the reverse osmosis system (11) is divided into two ways and respectively connected to the water inlet pipe of the yin-yang mixed bed (12) and the water inlet pipe of the ABFT biochemical treatment pool (2); the water outlet pipe of the yin-yang mixed bed (12) is divided into two ways and respectively connected to the water inlet pipe of the chemical regeneration wastewater tank (16) and the water inlet pipe of the desalted water tank (13); The outlet pipe of the desalted water tank (13) is divided into four routes and connected to the inlet pipe of the chemical laboratory (134), the inlet pipe of the hydrogen station (133), the inlet pipe of the water treatment regeneration equipment (132) and the inlet pipe of the boiler steam-water system (131); the outlet pipe of the boiler steam-water system (131) is connected to the inlet pipe of the fine treatment regeneration wastewater tank (14), the outlet pipe of the fine treatment regeneration wastewater tank (14) is connected to the inlet pipe of the steam stripping and distillation denitrification device (15), and the outlet pipe of the denitrification device (15) is connected to the inlet pipe of the nanofiltration device (18); the outlet pipe of the chemical regeneration wastewater tank (16) is connected to the inlet pipe of the filter B (17), and the outlet pipe of the filter B (17) is connected to the inlet pipe of the nanofiltration device (18); the outlet pipe of the nanofiltration device (18) is connected to the inlet pipe of the drying tower (21); The outlet pipe of the power plant desulfurization wastewater pool (19) is connected to the inlet pipe of the electrodialysis system (20), and the outlet pipe of the electrodialysis system (20) is connected to the water inlet pipe of the drying tower (21); The ABFT biochemical treatment pool (2) is internally divided into a decarbonization zone, a high-speed nitrification zone, a medium-speed nitrification zone, and a low-speed nitrification zone. The wastewater in the ABFT biochemical treatment pool (2) first passes through the decarbonization zone, then passes through the high-speed nitrification zone, then enters the medium-speed nitrification zone, and finally flows through the low-speed nitrification zone. A blower is also provided in the biochemical treatment pool (2).

2. According to claim 1, the system for deep recycling of urban water as industrial water for thermal power plants is characterized by: The intermediate water tank (3) is connected to the muddy water well (4) via a centrifugal pump, and the muddy water well (4) is also provided with a matching coagulant dosing device.

3. The system for deep recycling of urban water as industrial water for thermal power plants according to claim 1 is characterized by: The boiler steam-water system (131) is also provided with a processing and digestion module.

4. A method for operating a system for deep recycling of urban water as industrial water for thermal power plants as claimed in claim 1, characterized in that: The specific steps include: Step 1, the effluent of the sewage treatment plant (1) is transported to the ABFT biochemical treatment pool (2) in the power plant, and is biochemically treated through the decarbonization zone, high-speed nitrification zone, medium-speed nitrification zone, and low-speed nitrification zone of the ABFT biochemical treatment pool (2); the effluent of the ABFT biochemical treatment pool (2) is lifted to the muddy water well (4) by a centrifugal pump through the intermediate water pool (3), and the coagulant dosing device equipped with the muddy water well (4) is used to add the agent, and the effluent of the muddy water well (4) flows by gravity into the accelerated clarification pool (5) for sedimentation treatment, and the clear water after the sedimentation treatment flows into the clear water well (6); Step 2, one outlet water of the clean water well (6) is recycled to the circulating water system (7), and the circulating water system (7) provides water replenishment for the cooling tower (71). The outlet water of this outlet water is also supplied to the cooling water pump and industrial miscellaneous water; the other outlet water of the clean water well (6) is firstly subjected to deep treatment for water quality, and then enters the ultraviolet disinfection pool (8), after ultraviolet disinfection to remove bacteria and organic matter in the water and reduce TOC, the suspended particles are filtered out by the filter A (9), and after being pressurized by the booster pump, it enters the ultrafiltration system (10) to remove large molecular particles in the water, and then is pressurized again to enter the reverse osmosis system (11), and the reverse osmosis concentrated water produced in the reverse osmosis system (11) is returned to the ABFT biochemical treatment pool (2) for treatment, and the other produced water of the reverse osmosis system (11) is lifted by the centrifugal pump and enters the yin-yang mixed bed (12) for further desalination; the outlet water of the yin-yang mixed bed (12) enters the desalted water tank (13) and the chemical regeneration wastewater tank (16); Step 3, the desalted water tank (13) supplies water to the boiler steam-water system (131), and the desalted water tank (13) also supplies water to the water treatment regeneration equipment (132), the hydrogen station (133) and the chemical laboratory (134); the refined regeneration wastewater obtained by the boiler steam-water system (131) through the treatment digestion module flows into the refined regeneration wastewater tank (14); the refined regeneration wastewater in the refined regeneration wastewater tank (14) is denitrified by the steam stripping and rectification denitrification device (15), and then combined with the chemical regeneration wastewater in the chemical regeneration wastewater tank (16) after filtering out the insoluble matter by the filter B (17), and then enters the nanofiltration device (18) for classification after being pressurized by the booster pump; Step 4: After the desulfurization wastewater in the power plant desulfurization wastewater pool (19) is concentrated and reduced by the electrodialysis system (20), it is combined with the effluent from the nanofiltration device (18) and enters the drying tower (21). In the drying tower (21), the terminal wastewater is evaporated to dryness by the bypass flue evaporation technology, and the remaining ash is collected and transported out.

5. The working method of the system for deep recycling of urban water as industrial water for thermal power plants according to claim 4 is characterized in that: When the biochemical treatment is carried out in the ABFT biochemical treatment tank (2) in step (1), a blower is used to supply oxygen to the decarbonization zone, the high-speed nitrification zone, the medium-speed nitrification zone and the low-speed nitrification zone in the biochemical treatment tank (2).

6. The working method of the system for deep recycling of urban water as industrial water for thermal power plants according to claim 4 is characterized by: In step (1), the effluent from the sewage treatment plant (1) is transported to the ABFT biochemical treatment pool (2) in the power plant through a lifting pump and a pipe system.

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