Integrated process for cooperative treatment and up-to-standard discharge of industrial wastewater and domestic sewage of power plant

Abstract

The invention discloses an integrated process for cooperative treatment and up-to-standard discharge of industrial wastewater and domestic wastewater of a power plant, and relates to the field of cooperative treatment of wastewater and sewage, and the integrated process comprises the following steps: configuring a raw water collection system, setting a raw water source, configuring a multi-stage filtration and heating pretreatment process, configuring an ultrafiltration membrane system, and setting a fine filtration path. A first-stage reverse osmosis system is configured, reverse osmosis parameters are set, a second-stage reverse osmosis system is configured, a low-conductivity water treatment path is set, a mixed ion exchanger is configured, a desalted water output path is set, a standby pool body is set, and the adjusting capacity is set. A raw water collecting system, a multi-stage filtering and heating pretreatment process, an ultrafiltration membrane system, a first-stage reverse osmosis system, a second-stage reverse osmosis system, a mixed ion exchanger and a standby pool body are sequentially arranged in the process. The problems of unstable effluent quality, insufficient deep desalination capability and poor emergency regulation capability in a traditional power plant wastewater treatment mode can be effectively solved.

Description

Technical Field

[0001] This invention relates to the field of co-treatment of wastewater and sewage, and in particular to an integrated process for co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants. Background Technology

[0002] Power plants generate various types of wastewater during long-term operation, including boiler blowdown water, chemical makeup water concentrate, equipment flushing wastewater, and domestic sewage. These wastewaters are complex in composition, containing suspended particulate matter, colloidal impurities, dissolved salts, and organic pollutants, and are accompanied by nitrogen oxide emissions. Traditional processes mainly rely on single-source treatment or decentralized treatment, resulting in insufficient treatment efficiency, high operating costs, and difficulty in achieving unified water quality control and compliance with discharge standards in boiler systems and heating network makeup water systems of different pressure levels.

[0003] However, existing technical solutions have two main problems: First, they lack a coordinated treatment path for industrial wastewater and domestic sewage from power plants. Often, different types of wastewater are treated separately, and it is impossible to achieve a unified combination of bar screen slag removal, grit removal, coagulation flotation and biological filtration, resulting in insufficient overall removal rate. Second, they lack a water quality control mechanism that is linked to the operating parameters of the boiler's three-pressure steam drum. Existing dosing points and monitoring links cannot be dynamically coupled and adjusted based on real-time data of multiple parameters such as pH value, phosphate concentration and dissolved oxygen, causing fluctuations in boiler water quality and making it difficult to meet the high standards required for long-term stable operation of the boiler. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing an integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants. This process aims to achieve multi-stage gradient purification from raw water to demineralized water by establishing a unified raw water collection and multi-stage pretreatment system within the plant area, combined with ultrafiltration, reverse osmosis, mixed ion exchange, and backup tanks. Simultaneously, in the wastewater treatment stage, a screen for slag removal, a grit chamber, a coagulation reaction tank, a dissolved air flotation device, and a contact oxidation tank are configured, along with a high-efficiency sedimentation tank and a multi-media filter group, significantly improving the removal efficiency of impurities and pollutants. Furthermore, an ammonia addition device and phosphate buffer are introduced into the boiler's three-pressure steam drum circuit, and a water quality deviation identification formula and multi-parameter linkage control logic are established to ensure that the pH value and phosphate concentration of the boiler water remain stable within the set range, ultimately achieving the co-treatment, reuse, and compliant discharge of industrial wastewater and domestic sewage from power plants.

[0005] Therefore, this application provides an integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants, comprising the following steps:

[0006] Step S100: Deploy the control system and configure the distributed control system, including the actuators and field instruments.

[0007] Step S200: Configure the raw water collection system and set the raw water source; configure the multi-stage filtration and heating pretreatment process; configure the ultrafiltration membrane system and set the fine filtration path; configure the first-stage reverse osmosis system and set the reverse osmosis parameters; configure the second-stage reverse osmosis system and set the low conductivity water treatment path; configure the mixed ion exchanger and set the demineralized water output path; set the standby tank and set the adjustment capacity.

[0008] Step S300: Configure the sewage diversion system and set the sewage source category; configure the bar screen slag removal unit and set the large particle impurity interception path; configure the grit chamber and set the inorganic particle settling path; configure the coagulation reaction tank and dissolved air flotation device and set the bubble floc separation path.

[0009] Step S400: Configure the contact oxidation tank and set the ammonia nitrogen and organic matter removal paths; configure the high-efficiency sedimentation tank and set the chemical phosphorus removal and solid-liquid separation paths; configure the multi-media filter group and set the terminal interception path and operating parameters; configure the reuse water pipeline and online water quality monitoring device and set the emission compliance confirmation threshold; set the flue gas continuous emission monitoring device and set the particulate matter and gaseous pollutant monitoring paths.

[0010] Step S500: Configure the heating steam path and set the heat energy release logic for the three operating conditions of the steam turbine; configure the heating network water supply path and set the start-stop logic for normal water supply and emergency water supply; configure the heating network circulation equipment group and set the operating parameters of the heating circuit; configure the heating network return water purification unit and set the return water decontamination and reheating path; configure the air-cooled condensation circuit and set the iron ion filtration path and monitoring parameters.

[0011] Step S600: Configure the boiler feedwater ammonia addition device and set the boiler feedwater pH adjustment path; configure the three-pressure boiler drum water sampling and monitoring device and set the phosphate and pH control targets; configure the boiler water quality deviation identification formula and set the multi-parameter linkage control threshold; configure the dosing equipment redundancy and online analysis calibration program and set the operating boundary.

[0012] As a preferred embodiment of the present invention, step 100 specifically includes:

[0013] Step S100.1: Deploy the control system and configure the distributed control system.

[0014] In the power plant operation scenario, two gas turbine units and two auxiliary systems for the gas turbine units are deployed, and an independent gas turbine control system is set up for each gas turbine unit. The gas turbine control system adopts a modular architecture, specifically including: a gas turbine auxiliary machine control and gas turbine control subsystem, a gas turbine emergency shutdown subsystem, and a gas turbine condition monitoring subsystem.

[0015] The gas turbine auxiliary control and gas turbine control subsystem centrally manages the start-up and shutdown processes, fuel supply system, ignition system, combustion system, and exhaust system related to gas turbine operation. It executes automatic control logic and monitors pressure fluctuations in real time under different operating conditions of the gas turbine. The gas turbine emergency shutdown subsystem executes emergency shutdown logic when it detects a preset fault signal or when key operating parameters exceed safety thresholds. The gas turbine status monitoring subsystem is equipped with high-precision vibration sensors and operating status data acquisition devices to collect vibration amplitude, vibration frequency distribution, and dynamic response parameters of key locations. It also performs trend analysis and anomaly warning on the collected vibration data.

[0016] The configuration control system functions include: waste heat boiler, steam turbine and thermal auxiliary system. A distributed control system with a unified architecture is established in the waste heat boiler, steam turbine and thermal auxiliary system. The distributed control system includes: data acquisition system, sequential control system, mechanical control system, digital electro-hydraulic control system, electrical control system and denitrification control system.

[0017] Step S100.2: Configure the actuators and field instruments.

[0018] Field instrumentation equipment is configured in both the gas turbine control system and the distributed control system. Specifically, it includes: Rosemount and Yokogawa brand pressure transmitters and differential pressure transmitters to measure the real-time pressure and differential pressure of the main steam pipeline, auxiliary water supply pipeline and fuel gas system; UE and SOR brand pressure switches to output alarm signals when the differential pressure exceeds the set threshold at important nodes; and ROTORK brand electric actuators to precisely control the opening response of regulating valves, shut-off valves and positioning valves.

[0019] As a preferred embodiment of the present invention, step 200 specifically includes:

[0020] Step S200.1: Configure the raw water collection system and set the raw water source, configure the multi-stage filtration and heating pretreatment process, configure the ultrafiltration membrane system, and set the fine filtration path.

[0021] Step S200.2: Configure the primary reverse osmosis system and set the reverse osmosis parameters; configure the secondary reverse osmosis system and set the low conductivity water treatment path.

[0022] Step S200.3: Configure the mixed ion exchanger, set the demineralized water output path, set the standby tank, and set the adjustment capacity.

[0023] The permeate from the secondary reverse osmosis is pumped to the mixed-bed ion exchanger via a mixed-bed feed pump. The mixed-bed ion exchanger uses a mixed-bed structure of anion exchange resin and cation exchange resin, with a resin layer height of not less than 1200 mm and an exchange capacity of not less than 1000 liter equivalents per cubic meter. It is equipped with an online conductivity monitoring device. When the conductivity exceeds 0.2 microsiemens per centimeter, the regeneration process is triggered. Regeneration uses alternating cleaning with dilute sulfuric acid and sodium hydroxide solution. The effluent enters the demineralized water tank, and the demineralized water is pumped to the main plant building as boiler feedwater, heating network feedwater, and process spray water.

[0024] The backup water treatment equipment includes a clarifier and a variable porosity filter. The clarifier has a volume of 150 cubic meters to achieve suspended solids sedimentation and water volume regulation. The variable porosity filter adopts an adjustable filtration rate structure with a filtration rate range of 8 to 12 meters per hour. Under special operating conditions, it can be switched to operate via valves as a pretreatment bypass.

[0025] As a preferred embodiment of the present invention, step 300 specifically includes:

[0026] Step S300.1: Configure the sewage diversion system and set the sewage source category, configure the bar screen slag removal unit and set the large particle impurity interception path.

[0027] Step S300.2: Configure the grit chamber and set the inorganic particle settling path; configure the coagulation reaction tank and set the coagulation reaction parameters.

[0028] Step S300.3: Configure the dissolved air flotation device and set the bubble floc separation path.

[0029] The dissolved air flotation device is a rectangular horizontal flow flotation tank, 10 meters long, 3 meters wide, and 2.5 meters deep, with a volume of 75 cubic meters. The dissolved air system includes a high-pressure dissolved air pump, a dissolved air tank, a microbubble releaser, and a return water pump. The high-pressure dissolved air pump operates at a pressure of 0.5 MPa, the dissolved air tank has an effective volume of 2 cubic meters, the microbubble releaser nozzle has a diameter of no more than 30 micrometers, and the return water pump has a flow rate of 5 cubic meters per hour.

[0030] A return water pump draws a portion of the effluent from the flotation tank, pressurizes it, and sends it into the dissolved air tank, where the air is fully dissolved under high pressure. The dissolved air water then enters the flotation tank through a release device, forming microbubbles. These microbubbles combine with the coagulated flocs and float to the surface to form scum. The scum is scraped into the scum collection trough by a chain scraper and finally transported to the scum box by a conveyor belt. The effluent from the flotation tank flows into the deep biological treatment unit through an overflow weir.

[0031] As a preferred embodiment of the present invention, step 400 specifically includes:

[0032] Step S400.1: Configure the contact oxidation tank and set the ammonia nitrogen and organic matter removal paths; configure the high-efficiency sedimentation tank and set the chemical phosphorus removal and solid-liquid separation paths.

[0033] Step S400.2: Configure the multi-media filter group, set the terminal interception path and operating parameters, configure the reuse water supply pipeline, and set the heating network water supply and spray water supply paths.

[0034] Step S400.3: Configure an online water quality monitoring device and set a threshold for confirming compliance with emission standards. Set up a continuous emission monitoring device for flue gas and set up monitoring paths for particulate matter and gaseous pollutants.

[0035] The effluent from the multi-media filter that is not reused flows into the compliant water buffer tank. The compliant water buffer tank is a rectangular reinforced concrete tank with a volume of 50 cubic meters. It is equipped with a level gauge and a low-speed paddle agitator to prevent water stratification. An online water quality monitoring device is installed on the effluent pipeline of the compliant water buffer tank. The online water quality monitoring device includes a multi-parameter water quality analyzer, an automatic sampler, and a data acquisition and transmission module. The detection frequency is set to once every 15 minutes.

[0036] The monitoring data is transmitted to the historical database of the distributed control system's data acquisition system via industrial Ethernet for retention and linkage judgment. The compliance judgment thresholds are set as follows: chemical oxygen demand not exceeding 50 mg / L, ammonia nitrogen not exceeding 5 mg / L, and total phosphorus not exceeding 0.5 mg / L. When the results of three consecutive tests meet the compliance judgment thresholds, the electric discharge valve of the compliant water buffer tank is opened, and the effluent is discharged into the municipal sewage pipe network.

[0037] The high-temperature flue gas emitted by the gas turbine unit enters a vertical exhaust chimney after heat exchange in a waste heat boiler. The exhaust chimney is 60 meters high, with its inner wall coated with acid and alkali resistant anti-corrosion materials. An exhaust diffusion cap is installed at the top, and a continuous emission monitoring device is installed at a height of 15 meters above the ground. The continuous emission monitoring device consists of a laser dust concentration detector, an ultraviolet differential absorption spectrometer, and a data recording module. The laser dust concentration detector is used to measure particulate matter concentration, the ultraviolet differential absorption spectrometer is used to measure sulfur dioxide and nitrogen oxide concentrations, and the data recording module stores and uploads monitoring data at 1-minute intervals.

[0038] The alarm thresholds for the continuous emission monitoring device are set as follows: particulate matter concentration 30 mg / m³, sulfur dioxide concentration 35 mg / m³, and nitrogen oxide concentration 50 mg / m³. When any indicator exceeds the corresponding alarm threshold, the data recording module sends a linkage load reduction control command to the distributed control system, and the gas turbine unit performs load reduction operation.

[0039] As a preferred embodiment of the present invention, step 500 specifically includes:

[0040] Step S500.1: Configure the heating steam path and set the heat energy release logic for the three operating conditions of the steam turbine. Configure the heating network water supply path and set the start and stop logic for normal water supply and emergency water supply.

[0041] Step S500.2: Configure the heating network circulation equipment group and set the operating parameters of the heating circuit, configure the heating network return water purification unit, and set the return water decontamination and reheating path.

[0042] Step S500.3: Configure the air-cooled condensation circuit and set the iron ion filtration path and monitoring parameters. At the cold end of turbine number 3, which uses direct air cooling, an air-cooled condensate and condensate iron removal unit is installed, including: an air-cooled condensate pre-condensation pump, an iron removal filter, and iron ion monitoring and backwashing.

[0043] When the online monitoring value or verification value is higher than the control threshold, the sequential control system of the distributed control system sends a command to the backwash electric valve group of the iron removal filter to start the backwash program. The backwash duration is set to 8 minutes. At the same time as the backwash starts, the flow rate of the condensate pre-pump is reduced to stabilize the pipeline pressure.

[0044] As a preferred embodiment of the present invention, the 600 specifically includes:

[0045] Step S600.1: Configure the boiler feedwater ammonia addition device and set the boiler feedwater pH adjustment path; configure the three-pressure boiler drum water sampling and monitoring device and set the phosphate and pH control targets.

[0046] Step S600.2: Configure the boiler water quality deviation identification formula, set the multi-parameter linkage control threshold, configure the redundancy of the dosing equipment and the online analysis calibration program, and set the operating boundary.

[0047] A water quality deviation identification function is set in the high-pressure boiler water control to jointly determine the deviation between phosphate concentration and pH value.

[0048] When ΔR>0.20, the data acquisition system of the distributed control system issues a trend deviation alarm signal and sends a dosing correction command to the digital electro-hydraulic control system. The multi-parameter linkage control threshold is set as follows: when the phosphate concentration decreases at a rate ≥10% / h for 60 consecutive minutes and the pH value decreases synchronously, the frequency of the phosphate metering pump is increased by 5% to 10%; when the pH value increases while the phosphate concentration decreases, it is determined that the ammonia dosage is too high, and the frequency of the ammonia metering pump is reduced by 5% to 10%; when the conductivity increases by more than 15% of the monthly average and the dissolved oxygen concentration exceeds the process control line of 20 μg / L, supplementary sampling and manual testing are triggered, and the adjustment coefficients for phosphate and ammonia dosage are temporarily reduced by 5% each.

[0049] All three sets of online ammonia dosing devices and three sets of phosphate dosing devices are equipped with a dual-metering pump redundancy structure. The operating pump and the standby pump automatically rotate every 48 hours. The pH online monitor and the phosphate online analyzer are equipped with automatic cleaning and two-point calibration programs with a calibration cycle of 72 hours. The water quality exceeding the limit warning boundary is set to 95% of the upper and lower control limits: when the pH value or phosphate concentration reaches the corresponding warning boundary, the decentralized control system issues a warning and records the event.

[0050] Manual testing and verification are conducted quarterly. Ion chromatography and potentiometric titration are used to compare online monitoring data, with an allowable deviation of ±5%. Both the dosing valve and the sampling valve are assigned unique identification numbers, which are then matched with the corresponding loops in the distributed control system screen.

[0051] In summary, the integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants provided in this application, by sequentially configuring a raw water collection system, a multi-stage filtration and heating pretreatment process, an ultrafiltration membrane system, a primary reverse osmosis system, a secondary reverse osmosis system, a mixed ion exchanger, and a backup tank in the process, can effectively solve the problems of unstable effluent quality, insufficient deep desalination capacity, and deficiencies in emergency regulation capacity in traditional power plant wastewater treatment methods. Furthermore, this process, combined with a sewage diversion system, a bar screen unit, a grit chamber, a coagulation reaction tank, and a dissolved air flotation device, further enhances the interception and separation of large particulate impurities and suspended solids, avoiding the low treatment efficiency caused by single physicochemical or single biological treatment paths. Finally, through the combined operation of a contact oxidation tank, a high-efficiency sedimentation tank, a multi-media filter group, and an online water quality monitoring device, it achieves efficient removal and continuous compliant discharge of pollutants such as ammonia nitrogen, COD, and total phosphorus. This not only meets the power plant's demand for high-quality makeup water but also ensures that the discharged water consistently meets environmental standards, significantly improving the safety, stability, and environmental benefits of the system operation. Attached Figure Description

[0052] Figure 1 This is an overall flow chart of an integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants, provided in an embodiment of this application. Detailed Implementation

[0053] Please refer to Figure 1 The diagram illustrates a flow chart of an embodiment of an integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from a power plant, in accordance with the present disclosure.

[0054] like Figure 1 As shown, an integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants includes the following steps:

[0055] Step S100: Deploy the control system and configure the distributed control system, including the actuators and field instruments.

[0056] Step S200: Configure the raw water collection system and set the raw water source; configure the multi-stage filtration and heating pretreatment process; configure the ultrafiltration membrane system and set the fine filtration path; configure the first-stage reverse osmosis system and set the reverse osmosis parameters; configure the second-stage reverse osmosis system and set the low conductivity water treatment path; configure the mixed ion exchanger and set the demineralized water output path; set the standby tank and set the adjustment capacity.

[0057] Step S300: Configure the sewage diversion system and set the sewage source category; configure the bar screen slag removal unit and set the large particle impurity interception path; configure the grit chamber and set the inorganic particle settling path; configure the coagulation reaction tank and dissolved air flotation device and set the bubble floc separation path.

[0058] Step S400: Configure the contact oxidation tank and set the ammonia nitrogen and organic matter removal paths; configure the high-efficiency sedimentation tank and set the chemical phosphorus removal and solid-liquid separation paths; configure the multi-media filter group and set the terminal interception path and operating parameters; configure the reuse water pipeline and online water quality monitoring device and set the emission compliance confirmation threshold; set the flue gas continuous emission monitoring device and set the particulate matter and gaseous pollutant monitoring paths.

[0059] Step S500: Configure the heating steam path and set the heat energy release logic for the three operating conditions of the steam turbine; configure the heating network water supply path and set the start-stop logic for normal water supply and emergency water supply; configure the heating network circulation equipment group and set the operating parameters of the heating circuit; configure the heating network return water purification unit and set the return water decontamination and reheating path; configure the air-cooled condensation circuit and set the iron ion filtration path and monitoring parameters.

[0060] Step S600: Configure the boiler feedwater ammonia addition device and set the boiler feedwater pH adjustment path; configure the three-pressure boiler drum water sampling and monitoring device and set the phosphate and pH control targets; configure the boiler water quality deviation identification formula and set the multi-parameter linkage control threshold; configure the dosing equipment redundancy and online analysis calibration program and set the operating boundary.

[0061] As a preferred embodiment of the present invention, step 100 specifically includes:

[0062] Step S100.1: Deploy the control system and configure the distributed control system.

[0063] In the power plant operation scenario, two gas turbine units and two auxiliary systems for the gas turbine units are deployed, and an independent gas turbine control system is set up for each gas turbine unit. The gas turbine control system adopts a modular architecture, specifically including: a gas turbine auxiliary machine control and gas turbine control subsystem, a gas turbine emergency shutdown subsystem, and a gas turbine condition monitoring subsystem.

[0064] The gas turbine auxiliary control and gas turbine control subsystem centrally manages the start-up and shutdown processes, fuel supply system, ignition system, combustion system, and exhaust system related to gas turbine operation. It executes automatic control logic and monitors pressure fluctuations in real time under different operating conditions of the gas turbine. The gas turbine emergency shutdown subsystem executes emergency shutdown logic when it detects a preset fault signal or when key operating parameters exceed safety thresholds. The gas turbine status monitoring subsystem is equipped with high-precision vibration sensors and operating status data acquisition devices to collect vibration amplitude, vibration frequency distribution, and dynamic response parameters of key locations. It also performs trend analysis and anomaly warning on the collected vibration data.

[0065] The configuration control system functions include: waste heat boiler, steam turbine and thermal auxiliary system. A distributed control system with a unified architecture is established in the waste heat boiler, steam turbine and thermal auxiliary system. The distributed control system includes: data acquisition system, sequential control system, mechanical control system, digital electro-hydraulic control system, electrical control system and denitrification control system.

[0066] The data acquisition system is used to collect operating parameters of the boiler, turbine, and thermal auxiliary equipment, including temperature, pressure, flow rate, and equipment start-up and shutdown status data. The sequential control system is used to execute sequential logic control of multiple devices and multiple loops, ensuring the correct execution of the start-up, switching, and standby logic operations of the main loop. The mechanical control system is used to execute start-up and shutdown control, isolation control, switching control, speed regulation control, and torque regulation of the turbine unit and mechanical components. The digital electro-hydraulic control system is used to control the opening of the main steam valve, regulating valve, and switching valve through digital logic to achieve rapid response and precise regulation. The electrical control system is used to execute start-up and shutdown operations and collect operating status data of high-voltage motors, pumps, electric actuators, and circuit breakers. The denitrification control system is used to control nitrogen oxide emissions during the operation of the gas-fired waste heat boiler, and to execute reducing agent flow regulation, reactor temperature regulation, and ammonia-nitrogen ratio feedback regulation.

[0067] Step S100.2: Configure the actuators and field instruments.

[0068] Field instrumentation equipment is configured in both the gas turbine control system and the distributed control system. Specifically, it includes: Rosemount and Yokogawa brand pressure transmitters and differential pressure transmitters to measure the real-time pressure and differential pressure of the main steam pipeline, auxiliary water supply pipeline and fuel gas system; UE and SOR brand pressure switches to output alarm signals when the differential pressure exceeds the set threshold at important nodes; and ROTORK brand electric actuators to precisely control the opening response of regulating valves, shut-off valves and positioning valves.

[0069] All field instruments and equipment use digital signal output and are connected to the main control system via industrial Ethernet and fieldbus communication protocols.

[0070] As a preferred embodiment of the present invention, step 200 specifically includes:

[0071] Step S200.1: Configure the raw water collection system and set the raw water source, configure the multi-stage filtration and heating pretreatment process, configure the ultrafiltration membrane system, and set the fine filtration path.

[0072] Raw water delivery pipelines are deployed within the factory area to divert municipal tap water and mine drainage water to the clear water tank. The clear water tank serves as a unified water intake point, with functions of temporary storage and water volume balancing. The water effluent from the clear water tank is drawn by a chemical water supply pump and transported to the raw water heater. The chemical water supply pump is a centrifugal type with a rated flow rate of 60 cubic meters per hour, and two pumps are connected in parallel.

[0073] The effluent from the clear water tank is pumped to the raw water heater via a chemical feed water pump. The raw water heater adopts a steam heat exchange tube bundle structure, and the effluent temperature ranges from 25℃ to 35℃. The heated water enters the dual-media filter group, which consists of four dual-media filters connected in parallel. Each dual-media filter has a built-in quartz sand filter layer and anthracite filter layer with a filter layer thickness of 1000 mm and a filtration accuracy of 5 microns to 10 microns. Each dual-media filter is equipped with a backwashing device, and the backwashing cycle is once every 24 hours.

[0074] It can reduce the risk of scaling in membrane treatment devices and remove large particulate suspended solids, providing stable feed water for subsequent ultrafiltration devices.

[0075] The effluent from the dual-media filter group enters the ultrafiltration unit group, which consists of four hollow fiber membrane ultrafiltration units connected in parallel. The membrane pore size is 0.01 microns, and the operation mode is cross-flow filtration. The transmembrane pressure difference is set between 0.1 MPa and 0.3 MPa. The ultrafiltration unit group is equipped with a chemical cleaning device with a cleaning cycle of 48 hours. The ultrafiltration permeate is stored in the ultrafiltration permeate tank and then transported to the first-stage reverse osmosis unit.

[0076] It can remove colloids, viruses, and fine particles, ensuring the cleanliness of the feed water for the first-stage reverse osmosis unit.

[0077] Step S200.2: Configure the primary reverse osmosis system and set the reverse osmosis parameters; configure the secondary reverse osmosis system and set the low conductivity water treatment path.

[0078] The ultrafiltration permeate is pressurized by the first-stage reverse osmosis booster pump and enters the first-stage reverse osmosis security filter, with a filtration accuracy of 5 microns. It then enters the first-stage reverse osmosis high-pressure pump, with a pressurization range of 1.5 MPa to 2.5 MPa, and is sent to the first-stage reverse osmosis unit. The first-stage reverse osmosis unit uses polyamide composite membrane modules with an average desalination rate of 98%. The permeate is stored in the first-stage reverse osmosis permeate tank. Part of it is sent to the heating network spray system, and part of it is used as feed water for the second-stage reverse osmosis unit. The concentrate is discharged into the sewage network and undergoes neutralization treatment.

[0079] It can remove most of the dissolved salts, reducing the conductivity of the water to below 30 microsiemens per centimeter.

[0080] The primary reverse osmosis permeate is pressurized by the secondary reverse osmosis booster pump and enters the secondary reverse osmosis security filter with a filtration accuracy of 1 micron. Then it enters the secondary reverse osmosis high-pressure pump, with a pressurization range of 1.0 MPa to 1.8 MPa, and is sent to the secondary reverse osmosis unit. The secondary reverse osmosis unit uses a high desalination rate composite membrane module, and the permeate conductivity threshold is no higher than 10 microsiemens per centimeter. The permeate is stored in the secondary reverse osmosis permeate tank, mixed with the feed water of the ion exchanger, and the concentrate is partially returned to the clear water tank.

[0081] It can further reduce residual salt content, enabling the produced water to meet the low conductivity standard and reduce fresh water consumption.

[0082] Step S200.3: Configure the mixed ion exchanger, set the demineralized water output path, set the standby tank, and set the adjustment capacity.

[0083] The permeate from the secondary reverse osmosis is pumped to the mixed-bed ion exchanger via a mixed-bed feed pump. The mixed-bed ion exchanger uses a mixed-bed structure of anion exchange resin and cation exchange resin, with a resin layer height of not less than 1200 mm and an exchange capacity of not less than 1000 liter equivalents per cubic meter. It is equipped with an online conductivity monitoring device. When the conductivity exceeds 0.2 microsiemens per centimeter, the regeneration process is triggered. Regeneration uses alternating cleaning with dilute sulfuric acid and sodium hydroxide solution. The effluent enters the demineralized water tank, and the demineralized water is pumped to the main plant building as boiler feedwater, heating network feedwater, and process spray water.

[0084] It can remove trace residual ions, making the resistivity of deionized water reach more than 5 megohms per centimeter, which meets the requirements of high-parameter boilers.

[0085] The backup water treatment equipment includes a clarifier and a variable porosity filter. The clarifier has a volume of 150 cubic meters to achieve suspended solids sedimentation and water volume regulation. The variable porosity filter adopts an adjustable filtration rate structure with a filtration rate range of 8 to 12 meters per hour. Under special operating conditions, it can be switched to operate via valves as a pretreatment bypass.

[0086] As a preferred embodiment of the present invention, step 300 specifically includes:

[0087] Step S300.1: Configure the sewage diversion system and set the sewage source category, configure the bar screen slag removal unit and set the large particle impurity interception path.

[0088] A closed gravity drainage network system is deployed within the power plant area. The drainage network includes: boiler blowdown pipelines, chemical makeup water concentrate discharge pipelines, equipment flushing wastewater discharge ditches, and domestic sewage discharge ditches.

[0089] The boiler blowdown pipe is specifically designed to collect boiler blowdown water discharged periodically from the boiler. The pipe is made of corrosion-resistant ceramic composite pipe with a diameter of DN80 and the joint adopts a high-temperature self-sealing structure. The chemical makeup water concentrate discharge pipe is specifically designed to collect concentrate from the reverse osmosis system. The pipe is made of fiberglass with a diameter of DN65 and a pressure resistance rating of PN10. The equipment flushing wastewater discharge channel and the domestic sewage discharge channel share a common mixed drainage channel, and the surface of the channel is coated with alkali-resistant anti-corrosion material.

[0090] Boiler blowdown pipes, chemical makeup water concentrate discharge pipes, equipment flushing wastewater discharge channels, and domestic sewage discharge channels all converge into a sewage collection well. The sewage collection well is a reinforced concrete structure with an epoxy anti-corrosion coating on the inner wall and a volume of 50 cubic meters. A liquid level detection float device is installed at the top of the sewage collection well. When the sewage level reaches 80% of the volume, the control cabinet is automatically triggered to start the lift pump. Two submersible sewage lift pumps are installed in the sewage collection well and operate in parallel. Each pump has a rated power of 7.5kW, a flow rate of 30 cubic meters per hour, and a head of 15 meters. The pump body is made of stainless steel, and the impeller has an anti-winding structure. The control system adopts a soft start mode. The sewage lift pump outlet is transported to the inlet of the mechanical bar screen slag removal equipment through a DN100 conveying pipeline.

[0091] Wastewater is pumped into the mechanical bar screen removal equipment via a lift pump. The mechanical bar screen removal equipment adopts a rotary chain structure, is made of 304 stainless steel, and has a bar spacing of 10 mm. Wastewater passes through the bars from bottom to top, and floating objects and large particles are intercepted. The mechanical grab rake is driven by a chain to periodically scrape the intercepted impurities to the top discharge hopper. The bottom of the discharge hopper is connected to a screw compactor, which compacts the screenings to a moisture content of less than 50%. The compacted screenings are then discharged into the screenings box.

[0092] The mechanical bar screen is set to run automatically twice per hour, with each run lasting 3 minutes. It also has a manual start mode. The effluent from the mechanical bar screen flows into the horizontal grit chamber by gravity.

[0093] Step S300.2: Configure the grit chamber and set the inorganic particle settling path; configure the coagulation reaction tank and set the coagulation reaction parameters.

[0094] The sedimentation tank adopts a horizontal rectangular structure, with a length of 8 meters, a width of 2.5 meters, a water depth of 2 meters, and a volume of 40 cubic meters. The designed hydraulic retention time is 25 to 30 minutes. A guide wall is installed at the inlet of the sedimentation tank to disperse the kinetic energy of the water flow and reduce short-circuiting. An overflow weir is installed at the outlet.

[0095] The bottom of the grit chamber is designed with a longitudinal V-shaped slope of 1:5, which facilitates the sliding of sedimented sand particles to the sand collection trough in the center of the bottom of the chamber. The sand collection trough is 0.4 meters wide and is equipped with a spiral sand conveyor at the bottom. The motor power of the sand conveyor is 1.5kW. The spiral sand conveyor transports the sedimented sand particles to the sand-water separator. The sand-water separator adopts a rotating spiral structure, with the main body made of carbon steel and lined with polyethylene. It reduces the moisture content of the sand particles to below 30%. The dewatered sand particles enter the solid waste collection area, and the effluent from the grit chamber enters the coagulation reaction tank through overflow.

[0096] The coagulation reaction tank is divided into two parts: a rapid mixing tank and a slow flocculation tank. The rapid mixing tank has a volume of 3 cubic meters and is equipped with a vertical shaft high-speed agitator with a four-bladed folding impeller and a mixing speed of 100 rpm. The slow flocculation tank has a volume of 7 cubic meters and is equipped with a frame-type agitator with a mixing speed of 30 rpm.

[0097] The coagulant dosing system includes a storage tank, a metering pump, and a pipeline mixer. The storage tank has a volume of 1.5 cubic meters, the metering pump has a metering accuracy of ±1%, the coagulant is a liquid polyaluminum chloride solution, the dosing concentration is 100 to 150 mg / L, the dosing point is set at the inlet of the rapid mixing tank, and a transparent observation window is set on the top of the coagulation reaction tank to monitor the floc formation. After the coagulation reaction is completed, the water enters the dissolved air flotation device.

[0098] Step S300.3: Configure the dissolved air flotation device and set the bubble floc separation path.

[0099] The dissolved air flotation device is a rectangular horizontal flow flotation tank, 10 meters long, 3 meters wide, and 2.5 meters deep, with a volume of 75 cubic meters. The dissolved air system includes a high-pressure dissolved air pump, a dissolved air tank, a microbubble releaser, and a return water pump. The high-pressure dissolved air pump operates at a pressure of 0.5 MPa, the dissolved air tank has an effective volume of 2 cubic meters, the microbubble releaser nozzle has a diameter of no more than 30 micrometers, and the return water pump has a flow rate of 5 cubic meters per hour.

[0100] A return water pump draws a portion of the effluent from the flotation tank, pressurizes it, and sends it into the dissolved air tank, where the air is fully dissolved under high pressure. The dissolved air water then enters the flotation tank through a release device, forming microbubbles. These microbubbles combine with the coagulated flocs and float to the surface to form scum. The scum is scraped into the scum collection trough by a chain scraper and finally transported to the scum box by a conveyor belt. The effluent from the flotation tank flows into the deep biological treatment unit through an overflow weir.

[0101] As a preferred embodiment of the present invention, step 400 specifically includes:

[0102] Step S400.1: Configure the contact oxidation tank and set the ammonia nitrogen and organic matter removal paths; configure the high-efficiency sedimentation tank and set the chemical phosphorus removal and solid-liquid separation paths.

[0103] Wastewater treated by dissolved air flotation is introduced into a contact oxidation tank by gravity flow. The contact oxidation tank is a reinforced concrete structure with dimensions of 12 meters long, 4 meters wide, and 4 meters deep, for a total volume of 192 cubic meters. The hydraulic retention time is set to 8 hours. The contact oxidation tank is equipped with three-dimensional elastic polyethylene packing material with a specific surface area of ​​not less than 350 square meters per cubic meter and a packing height of 3 meters, for the growth of biofilm microorganisms. Liftable microporous aeration pipes are arranged at the bottom of the contact oxidation tank. The aeration pipes are connected to two Roots blowers via air mains. Each Roots blower has an air volume of 50 cubic meters per minute and an air pressure of 58 kPa. The air mains are equipped with swirl-type air volume regulating valves and silencers. The microporous aeration heads have a bubble diameter of no more than 2 mm to maintain the dissolved oxygen conditions required for nitrification. The effluent from the contact oxidation tank flows into the subsequent sedimentation structure via an overflow weir.

[0104] The effluent from the contact oxidation tank enters the high-efficiency sedimentation tank, which adopts an inclined plate sedimentation structure. The tank dimensions are 10 meters long, 3 meters wide, and 3 meters deep. The inclined plate assembly is made of polypropylene, with an inclination angle of 60° and a spacing of 50 mm between the plates, resulting in an equivalent sedimentation area of ​​60 square meters. A chemical phosphorus removal dosing point is installed on the inlet pipe section of the high-efficiency sedimentation tank. The phosphorus removal agent is ferric chloride solution, with a concentration set at 5% and a dosage set at 1.2 liters per cubic meter of treated water. The dosing device consists of a 500-liter storage tank, a peristaltic metering pump with a metering accuracy of ±1%, and an electric regulating valve.

[0105] After the dosing, iron phosphate flocs are formed in the inclined plate area and collected to the bottom of the tank along with the settled sludge. The sludge is discharged to the sludge temporary storage unit through the sludge discharge pipe at the bottom of the tank at regular intervals. The effluent from the high-efficiency sedimentation tank flows into the deep filtration unit through the effluent weir. The effluent turbidity control threshold is set to no higher than 3 NTU, and the total phosphorus concentration control threshold is set to no higher than 0.3 mg / L.

[0106] Step S400.2: Configure the multi-media filter group, set the terminal interception path and operating parameters, configure the reuse water supply pipeline, and set the heating network water supply and spray water supply paths.

[0107] The effluent from the high-efficiency sedimentation tank enters the multi-media filter group, which consists of two vertical cylindrical filters connected in parallel. Each filter has a diameter of 1200 mm and a height of 2500 mm. Each multi-media filter is filled from bottom to top with a gravel support layer, a quartz sand layer, and an anthracite layer, with a total filter media height of 1.6 meters.

[0108] The gravel support layer has a particle size of 5-8 mm and a thickness of 200 mm; the quartz sand layer has a particle size of 1-2 mm and a thickness of 900 mm; and the anthracite coal layer has a particle size of 0.5-1 mm and a thickness of 500 mm.

[0109] The filter operation flow rate is set to 8 meters per hour, the working pressure is set to 0.3 MPa, each multi-media filter is equipped with an automatic backwashing program, the backwashing intensity is set to 12 liters per second per square meter, the backwashing time is set to 10 minutes, the backwashing start condition is that the inlet and outlet water pressure difference reaches 0.08 MPa or the running time reaches 48 hours, and the multi-media filter effluent suspended solids concentration control threshold is set to no more than 5 mg per liter.

[0110] The effluent from the multi-media filter is proportionally distributed into the reuse water pipeline. The reuse water pipeline is made of stainless steel with a diameter of DN100 and an epoxy coating on the inner wall for corrosion protection. The delivery pressure is set at 0.25 MPa. The reuse water pipeline is equipped with an electromagnetic flow meter and a pressure transmitter for continuous collection of flow and pressure data. Electric regulating valves are installed in the heating network water supply branch and the spray water supply branch to achieve flow ratio control. A return bypass is set on the main pipe. The opening of the return bypass electric regulating valve is linked to the terminal pressure to maintain a stable delivery pressure when the water consumption at the end changes suddenly. The effluent that is not reused is introduced into the qualified water buffer tank.

[0111] Step S400.3: Configure an online water quality monitoring device and set a threshold for confirming compliance with emission standards. Set up a continuous emission monitoring device for flue gas and set up monitoring paths for particulate matter and gaseous pollutants.

[0112] The effluent from the multi-media filter that is not reused flows into the compliant water buffer tank. The compliant water buffer tank is a rectangular reinforced concrete tank with a volume of 50 cubic meters. It is equipped with a level gauge and a low-speed paddle agitator to prevent water stratification. An online water quality monitoring device is installed on the effluent pipeline of the compliant water buffer tank. The online water quality monitoring device includes a multi-parameter water quality analyzer, an automatic sampler, and a data acquisition and transmission module. The detection frequency is set to once every 15 minutes.

[0113] The monitoring data is transmitted to the historical database of the distributed control system's data acquisition system via industrial Ethernet for retention and linkage judgment. The compliance judgment thresholds are set as follows: chemical oxygen demand not exceeding 50 mg / L, ammonia nitrogen not exceeding 5 mg / L, and total phosphorus not exceeding 0.5 mg / L. When the results of three consecutive tests meet the compliance judgment thresholds, the electric discharge valve of the compliant water buffer tank is opened, and the effluent is discharged into the municipal sewage pipe network.

[0114] The high-temperature flue gas emitted by the gas turbine unit enters a vertical exhaust chimney after heat exchange in a waste heat boiler. The exhaust chimney is 60 meters high, with its inner wall coated with acid and alkali resistant anti-corrosion materials. An exhaust diffusion cap is installed at the top, and a continuous emission monitoring device is installed at a height of 15 meters above the ground. The continuous emission monitoring device consists of a laser dust concentration detector, an ultraviolet differential absorption spectrometer, and a data recording module. The laser dust concentration detector is used to measure particulate matter concentration, the ultraviolet differential absorption spectrometer is used to measure sulfur dioxide and nitrogen oxide concentrations, and the data recording module stores and uploads monitoring data at 1-minute intervals.

[0115] The alarm thresholds for the continuous emission monitoring device are set as follows: particulate matter concentration 30 mg / m³, sulfur dioxide concentration 35 mg / m³, and nitrogen oxide concentration 50 mg / m³. When any indicator exceeds the corresponding alarm threshold, the data recording module sends a linkage load reduction control command to the distributed control system, and the gas turbine unit performs load reduction operation.

[0116] As a preferred embodiment of the present invention, step 500 specifically includes:

[0117] Step S500.1: Configure the heating steam path and set the heat energy release logic for the three operating conditions of the steam turbine. Configure the heating network water supply path and set the start and stop logic for normal water supply and emergency water supply.

[0118] During normal operation of the steam turbine, three heating steam paths are established in the steam power circuit according to the operating conditions of the steam turbine: the heating steam path for extraction and condensation conditions, the heating steam path for back pressure conditions, and the emergency heating steam path for full cut-off conditions.

[0119] The steam supply path for the extraction and condensation operation is as follows: a medium-low pressure connecting pipe is installed between the intermediate-pressure cylinder and the low-pressure cylinder of the turbine. A regulating valve is installed on the medium-low pressure connecting pipe to control the steam pressure and steam flow rate drawn from the connecting pipe. The drawn steam enters the inlet of the heating network heater through the connecting pipe and is used as heating steam for the heating network. The steam supply path for the back-pressure operation is as follows: a synchronous switching clutch is installed at the shaft system of the low-pressure cylinder of the turbine. The synchronous switching clutch is used to disconnect the low-pressure cylinder from the power circuit under back-pressure conditions. All steam from the intermediate-pressure cylinder exhaust port is directly connected to the inlet of the heating network heater via the intermediate-pressure cylinder exhaust pipe, and no longer enters the low-pressure cylinder. The emergency heating steam path under the full-cut condition is as follows: a high-pressure bypass and an intermediate-pressure bypass are set at the steam outlet of the waste heat boiler, and a desuperheating and pressure reducing device is connected in series after the high-pressure bypass and the intermediate-pressure bypass. The steam from the waste heat boiler is processed by the desuperheating and pressure reducing device of the high-pressure bypass and the intermediate-pressure bypass, and then merges with the main steam of the low-pressure cylinder at the parallel merging tee. The merged steam enters the heating network heater through the inlet of the heating network heater.

[0120] The switching of the heating steam path under condensing operation, back pressure operation, and emergency heating steam path under full-cut operation is jointly executed by the data acquisition system and the sequential control system of the distributed control system: the data acquisition system collects the heating network supply and return water temperature, heating network flow rate, steam pressure, and turbine load parameters, and the sequential control system controls the opening degree of the medium and low pressure connecting pipe regulating valve, high pressure bypass electric valve, and medium pressure bypass electric valve according to the set switching conditions to achieve automatic selection and switching of the heating steam path.

[0121] The heating network circulation loop is equipped with two water supply paths: a softened water supply path and an emergency water supply path from the Yellow River.

[0122] The softened water replenishment path is as follows: a deaerator water tank is installed at the softened water outlet. The deaerator water tank is used for temporary storage and deaeration. The softened water is pressurized to 0.35 MPa by the replenishment pump, and after being stabilized by the replenishment regulating valve, it is injected into the heating network circulating water pipeline. The effective volume of the deaerator water tank is 80 cubic meters, the softened water temperature is set to 105℃, and the replenishment pump is a vertical multistage centrifugal pump with a rated head of 35 meters and a rated flow rate of 25 cubic meters per hour.

[0123] The emergency water replenishment route for the Yellow River diversion is as follows: An emergency water replenishment valve is set up at the Yellow River water diversion access point. After the emergency water replenishment valve is opened, the Yellow River diversion water enters the inlet of the emergency water replenishment pump, which lifts the Yellow River diversion water to the water replenishment node of the heating network circulating water pipeline to achieve water replenishment in the event of an accident. The rated flow rate of the emergency water replenishment pump is 20 cubic meters per hour and the head is 30 meters.

[0124] The start and stop signals for the softened water replenishment path and the Yellow River emergency replenishment path are issued by the distributed control system based on the real-time data from the heating network pressure transmitter and the heating network flow meter. The opening degree of the replenishment regulating valve and the emergency replenishment valve is executed by the actuator of the digital electro-hydraulic control system.

[0125] Step S500.2: Configure the heating network circulation equipment group and set the operating parameters of the heating circuit, configure the heating network return water purification unit, and set the return water decontamination and reheating path.

[0126] The equipment configuration of the heating network circuit includes: four heating network circulating water pumps, four tubular heaters, two condensate coolers, two constant pressure pumps, and one emergency water supply pump.

[0127] The heating network circulating water pumps consist of four horizontal single-stage centrifugal pumps, each with a rated flow of 100 cubic meters per hour, a head of 40 meters, and a motor power of 45 kilowatts. The suction inlets of the four pumps are connected to the main return water pipe of the heating network, and the outlets are connected to the main outlet water pipe of the heating network. Four tubular heaters are made of stainless steel heat exchange tubes, each with a designed heat transfer area of ​​60 square meters. These four tubular heaters are connected in parallel between the main outlet water pipe of the heating network and the heating steam pipe for steam-circulating water heat exchange. Two condensate coolers are installed on the heating network steam condensate drain line, each with a heat exchange capacity of 0.8 megawatts. After the condensate cooler reaches the set temperature, it is discharged into the condensate header by a condensate pump. Two constant pressure pumps are installed on the constant pressure water supply branch, each with a head of 25 meters, to maintain constant pressure operation of the heating network circuit. One emergency water supply pump is installed upstream of the Yellow River emergency water supply path.

[0128] The target temperature for the outlet water of the heating network is 130℃, and the target temperature for the return water of the heating network is 60℃. The temperature control signal is collected by the electrical control system, and the control command is issued by the sequential control system to the actuator of the steam side regulating valve of the tubular heater.

[0129] The return water main of the heating network is equipped with a return water purification and return water reheating device: a return water decontamination device and a return water reheating device.

[0130] The return water cleaning device consists of a fully automatic backwashing cleaner installed in series on the main return water pipe of the heating network. The cleaner has a filtration accuracy of 100 microns and a rated processing capacity of 120 cubic meters per hour. The differential pressure transmitter of the cleaner is set with a differential pressure threshold of 0.05 MPa. When the threshold is reached, the backwashing program is triggered by the electrical control system. The return water reheating device consists of two water-to-water heat exchangers installed in parallel on the branch line after the return water is purified. The heat source for heat exchange is high-temperature condensate formed by the condensation of steam from the waste heat boiler. The heat transfer area of ​​a single water-to-water heat exchanger is 80 square meters. The opening of the valve on the heat exchange side is controlled by the electric actuator of the digital electro-hydraulic control system to stabilize the temperature of the return water entering the pump.

[0131] The purified return water from the heating network flows through pipes into the suction inlet of the heating network circulating water pump, forming a closed-loop circulation circuit.

[0132] Step S500.3: Configure the air-cooled condensation circuit and set the iron ion filtration path and monitoring parameters. At the cold end of turbine number 3, which uses direct air cooling, an air-cooled condensate and condensate iron removal unit is installed, including: an air-cooled condensate pre-condensation pump, an iron removal filter, and iron ion monitoring and backwashing.

[0133] The air-cooled condenser unit consists of an air-cooled condenser installed at the turbine exhaust port, which comprises a fan and a finned heat exchanger. The turbine exhaust steam is cooled by the air-cooled condenser to form condensate. The condensate pre-pump and iron removal filter are installed at the air-cooled condenser outlet, with two high-flow-rate iron removal filters connected in series at the pre-pump outlet. Each iron removal filter uses a magnetic filter element structure, with a single unit processing flow rate of 80 cubic meters per hour and a magnetic strength of 12,000 gauss. Iron ion monitoring and backwashing are performed by installing sampling points and online sampling devices on the condensate pipeline downstream of the iron removal filters. The iron ion concentration control threshold is set to 0.2 mg / L. Laboratory testing uses an atomic absorption spectrophotometer to periodically verify the retained samples.

[0134] When the online monitoring value or verification value is higher than the control threshold, the sequential control system of the distributed control system sends a command to the backwash electric valve group of the iron removal filter to start the backwash program. The backwash duration is set to 8 minutes. At the same time as the backwash starts, the flow rate of the condensate pre-pump is reduced to stabilize the pipeline pressure.

[0135] The air-cooled condensing circuit and the heating network circuit are physically isolated from each other on the heat exchange equipment, and independent valve groups and independent monitoring and control circuits are used between the pipelines to avoid cross-ingress of media.

[0136] As a preferred embodiment of the present invention, the 600 specifically includes:

[0137] Step S600.1: Configure the boiler feedwater ammonia addition device and set the boiler feedwater pH adjustment path; configure the three-pressure boiler drum water sampling and monitoring device and set the phosphate and pH control targets.

[0138] Three sets of online ammonia dosing devices are installed on the low-pressure, medium-pressure, and high-pressure feedwater main pipes, respectively. Each set of online ammonia dosing devices consists of an ammonia storage tank, a metering pump, a dosing mixer, a dosing flow control valve, and a dosing pipeline. The mass fraction of the ammonia solution is set to 1%, and the metering pump has a metering accuracy of ±1%. Online pH monitors are installed on the three feedwater main pipes, and the online pH monitoring data is connected to the data acquisition system of the distributed control system. The digital electro-hydraulic control system adjusts the metering pump frequency in a closed loop based on the online pH monitoring data to control the pH value of the boiler feedwater between 9.5 and 9.8, and stops the addition of hydrazine deoxidizer. The pH value of the boiler feedwater is adjusted entirely by ammonia solution.

[0139] Automatic samplers, online pH monitors, online phosphate analyzers, online conductivity monitors, and data acquisition modules are installed at the high-pressure boiler water control targets, medium-pressure boiler water control targets, and low-pressure boiler water control targets, respectively. The monitoring data is written into the historical database of the distributed control system's data acquisition system at 10-minute intervals for linkage control and trend analysis.

[0140] The control targets for the high-pressure boiler drum water are: phosphate concentration of 0.5–2.0 mg / L and pH of 9.0–10.0. Phosphate buffer and ammonia are added at the dosing point on the high-pressure feedwater main pipe. The phosphate dosage is controlled according to the online flow ratio. The control targets for the medium-pressure boiler drum water are: phosphate concentration of 1.0–6.0 mg / L and pH of 9.0–10.5. Phosphate and ammonia are added at the dosing point on the medium-pressure feedwater main pipe. The phosphate to ammonia dosage ratio is adjusted based on the online phosphate analysis results and the online pH monitoring results. The control targets for the low-pressure boiler drum water are: no phosphate buffer or solid alkalizing agent is added; only ammonia is continuously added at the ammonia addition point in the condensate circuit to adjust the pH, which is generally controlled between 8.8 and 9.3.

[0141] Step S600.2: Configure the boiler water quality deviation identification formula, set the multi-parameter linkage control threshold, configure the redundancy of the dosing equipment and the online analysis calibration program, and set the operating boundary.

[0142] A water quality deviation identification function is set in the high-pressure boiler water control system to jointly determine the deviation between phosphate concentration and pH value. Specifically:

[0143]

[0144] In the formula: This represents the current phosphate ion concentration in the boiler water, in mg / L. Set the phosphate ion concentration within the target control range, in mg / L, and pH as the current pH value of the boiler water. SD The current pH value of the boiler water is ΔR, which is the water quality deviation judgment value. When ΔR>0.20, it is determined that the boiler water quality deviates from the set control target and the dosing parameters need to be adjusted.

[0145] When ΔR>0.20, the data acquisition system of the distributed control system issues a trend deviation alarm signal and sends a dosing correction command to the digital electro-hydraulic control system. The multi-parameter linkage control threshold is set as follows: when the phosphate concentration decreases at a rate ≥10% / h for 60 consecutive minutes and the pH value decreases synchronously, the frequency of the phosphate metering pump is increased by 5% to 10%; when the pH value increases while the phosphate concentration decreases, it is determined that the ammonia dosage is too high, and the frequency of the ammonia metering pump is reduced by 5% to 10%; when the conductivity increases by more than 15% of the monthly average and the dissolved oxygen concentration exceeds the process control line of 20 μg / L, supplementary sampling and manual testing are triggered, and the adjustment coefficients for phosphate and ammonia dosage are temporarily reduced by 5% each.

[0146] All three sets of online ammonia dosing devices and three sets of phosphate dosing devices are equipped with a dual-metering pump redundancy structure. The operating pump and the standby pump automatically rotate every 48 hours. The pH online monitor and the phosphate online analyzer are equipped with automatic cleaning and two-point calibration programs with a calibration cycle of 72 hours. The water quality exceeding the limit warning boundary is set to 95% of the upper and lower control limits: when the pH value or phosphate concentration reaches the corresponding warning boundary, the decentralized control system issues a warning and records the event.

[0147] Manual testing and verification are conducted quarterly. Ion chromatography and potentiometric titration are used to compare online monitoring data, with an allowable deviation of ±5%. Both the dosing valve and the sampling valve are assigned unique identification numbers, which are then matched with the corresponding loops in the distributed control system screen.

[0148] In practical application, the above involves deploying two gas turbine units and their associated auxiliary systems at the power plant site. Each gas turbine unit is equipped with an independent gas turbine control system. The gas turbine control system adopts a modular architecture, including a gas turbine auxiliary control and gas turbine control subsystem, a gas turbine emergency shutdown subsystem, and a gas turbine condition monitoring subsystem. The gas turbine auxiliary control and gas turbine control subsystem is responsible for executing start-stop control and automatic operation logic for the fuel supply system, ignition system, combustion system, and exhaust system. The gas turbine emergency shutdown subsystem immediately performs a shutdown operation when it detects a pressure exceeding 1.2 MPa or a temperature exceeding 950 degrees Celsius. The gas turbine condition monitoring subsystem collects vibration amplitude and frequency distribution data in real time through vibration sensors installed on key parts of the turbine body and provides anomaly warnings based on trend analysis.

[0149] Next, a distributed control system is configured in the waste heat boiler, steam turbine, and thermal auxiliary system. The distributed control system consists of a data acquisition system, a sequential control system, a mechanical control system, a digital electro-hydraulic control system, an electrical control system, and a denitrification control system. The data acquisition system collects operating parameters including temperature, pressure, flow rate, and equipment start-up and shutdown status. The sequential control system ensures the correct execution of the equipment start-up and shutdown logic sequence. The mechanical control system completes the regulation of steam turbine speed and torque. The digital electro-hydraulic control system realizes the rapid adjustment of steam valves. The electrical control system controls the start-up and shutdown of pumps, motors, and circuit breakers. The denitrification control system initiates the reducing agent flow rate and ammonia-nitrogen ratio adjustment program when the nitrogen oxide concentration exceeds 50 mg / m³.

[0150] Subsequently, in the raw water collection and pretreatment stage, a raw water pipeline network is laid in the plant area to introduce municipal tap water and mine drainage water into the clear water tank. The effective volume of the clear water tank is not less than 200 cubic meters, which is used for water balance and temporary storage. The water effluent from the clear water tank is lifted in parallel by two chemical feed water pumps with a rated flow rate of 60 cubic meters per hour and enters the raw water heater. The raw water heater heats the water temperature to 25°C to 35°C. The heated water flows sequentially through a dual-media filter group and an ultrafiltration device group. The filtration accuracy of the dual-media filter is 5 microns to 10 microns, the pore size of the ultrafiltration membrane is 0.01 microns, and the transmembrane pressure difference is set in the range of 0.1 MPa to 0.3 MPa to ensure the stability of the feed water quality of the subsequent reverse osmosis unit.

[0151] Subsequently, in the deep desalination stage, the ultrafiltration permeate first enters the primary reverse osmosis system. After passing through a 5-micron precision security filter and being pressurized by a high-pressure pump with a pressure range of 1.5 MPa to 2.5 MPa, it is sent to the polyamide composite membrane reverse osmosis unit. The permeate conductivity is controlled below 30 microsiemens per centimeter. Part of the permeate is used as makeup water for the heating network spray, and the other part enters the secondary reverse osmosis system. The secondary reverse osmosis unit uses high desalination membrane modules, with the operating pressure set at 1.0 MPa to 1.8 MPa. The permeate conductivity threshold is controlled within 10 microsiemens per centimeter to ensure that the water quality entering the mixed ion exchanger meets the low conductivity requirements.

[0152] Then, in the wastewater treatment stage, a closed drainage network is deployed within the power plant area to collect boiler wastewater, chemical makeup water concentrate, equipment flushing wastewater, and domestic sewage into a 50-cubic-meter wastewater collection well. The wastewater collection well is equipped with two submersible wastewater lift pumps, each with a flow rate of 30 cubic meters per hour and a head of 15 meters. The effluent is sent to a mechanical bar screen for slag removal. The screen gap is 10 millimeters. The screen slag is processed by a screw compactor to reduce the moisture content to no more than 50%. The effluent flows through the screen into a grit chamber. The grit chamber is designed to have a hydraulic retention time of 25 to 30 minutes. After the sand particles are dehydrated by a screw conveyor and a sand-water separator, the moisture content is reduced to below 30%. The water then flows into a coagulation reaction tank, where 100 to 150 mg / L of polyaluminum chloride solution is added. After the reaction is completed, the water enters a dissolved air flotation device, where bubbles smaller than 30 microns combine with the flocs to float, achieving solid-liquid separation.

[0153] Finally, in the boiler water quality control stage, the boiler system adopts a three-pressure drum structure, namely a high-pressure drum, a medium-pressure drum, and a low-pressure drum. In the high-pressure drum boiler water, the phosphate concentration is controlled within the range of 0.5 mg / L to 2.0 mg / L, and the pH value is controlled within the range of 9.0 to 10.0. In the medium-pressure drum boiler water, the phosphate concentration is controlled within the range of 1.0 mg / L to 6.0 mg / L, and the pH value is controlled within the range of 9.0 to 10.5. In the low-pressure drum boiler water, the pH value is maintained within the range of 8.8 to 9.3 only by adding ammonia through the condensate circuit. The control system adopts real-time monitoring and multi-parameter coupling logic. When the phosphate concentration decreases at a rate exceeding 10% per hour and the pH value decreases simultaneously, the phosphate dosage is automatically increased. When the pH value rises and the phosphate concentration decreases, it is determined that the ammonia water is excessive and the dosing rate is automatically reduced.

Claims

1. An integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants, characterized in that, Includes the following steps: S100, deploy the control system, configure the distributed control system, and configure the actuators and field instruments; S200: Configure a raw water collection system and set the raw water source; configure a multi-stage filtration and heating pretreatment process; configure an ultrafiltration membrane system and set the fine filtration path; configure a first-stage reverse osmosis system and set the reverse osmosis parameters; configure a second-stage reverse osmosis system and set the low conductivity water treatment path; configure a mixed ion exchanger and set the demineralized water output path; set a spare tank and set the adjustment capacity. S300, configured with a sewage diversion system and set sewage source category, configured with a bar screen slag removal unit and set large particle impurity interception path, configured with a grit chamber and set inorganic particle settling path, configured with a coagulation reaction tank and dissolved air flotation device and set bubble floc separation path; S400, configured with a contact oxidation tank and set up ammonia nitrogen and organic matter removal paths, configured with a high-efficiency sedimentation tank and set up chemical phosphorus removal and solid-liquid separation paths, configured with a multi-media filter group and set up terminal interception paths and operating parameters, configured with a reuse water pipeline and an online water quality monitoring device and set up a discharge compliance confirmation threshold, set up a continuous emission monitoring device for flue gas and set up monitoring paths for particulate matter and gaseous pollutants. S500: Configure the heating steam path and set the heat energy release logic for three operating conditions of the steam turbine; configure the heating network water supply path and set the start and stop logic for normal water supply and emergency water supply; configure the heating network circulation equipment group and set the operating parameters of the heating circuit; configure the heating network return water purification unit and set the return water decontamination and reheating path; configure the air condensation circuit and set the iron ion filtration path and monitoring parameters. S600: Configure a boiler feedwater ammonia addition device and set the boiler feedwater pH adjustment path; configure a three-pressure boiler drum boiler water sampling and monitoring device and set phosphate and pH control targets; configure a boiler water quality deviation identification formula and set multi-parameter linkage control thresholds; configure dosing equipment redundancy and online analysis calibration program and set operating boundaries.

2. The integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants according to claim 1, characterized in that, The 100 specifically includes: S100.1 Deploy the control system and configure the distributed control system; In the power plant operation scenario, two gas turbine units and two auxiliary systems for the gas turbine units are deployed, and an independent gas turbine control system is set up for each gas turbine unit. The gas turbine control system adopts a modular architecture, specifically including: a gas turbine auxiliary machine control and gas turbine control subsystem, a gas turbine emergency shutdown subsystem, and a gas turbine status monitoring subsystem. The gas turbine auxiliary control and gas turbine control subsystem centrally manages the start-up and shutdown processes, fuel supply system, ignition system, combustion system, and exhaust system related to gas turbine operation. It also executes automatic control logic and monitors pressure fluctuations in real time under different operating conditions of the gas turbine. The gas turbine emergency shutdown subsystem executes emergency shutdown logic when it detects a preset fault signal or when key operating parameters exceed safety thresholds. The gas turbine status monitoring subsystem is equipped with high-precision vibration sensors and operating status data acquisition devices to collect vibration amplitude, vibration frequency distribution, and dynamic response parameters of key locations. It also performs trend analysis and anomaly warning on the collected vibration data. The configuration control system functions include: waste heat boiler, steam turbine and thermal auxiliary system. In the waste heat boiler, steam turbine and thermal auxiliary system, a distributed control system with a unified architecture is established. The distributed control system includes: data acquisition system, sequential control system, mechanical control system, digital electro-hydraulic control system, electrical control system and denitrification control system. S100.2 Configuring actuators and field instruments; Field instrumentation equipment is configured in both the gas turbine control system and the distributed control system. Specifically, it includes: Rosemount and Yokogawa brand pressure transmitters and differential pressure transmitters to measure the real-time pressure and differential pressure of the main steam pipeline, auxiliary water supply pipeline and fuel gas system; UE and SOR brand pressure switches to output alarm signals when the differential pressure exceeds the set threshold at important nodes; and ROTORK brand electric actuators to precisely control the opening response of regulating valves, shut-off valves and positioning valves.

3. The integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants according to claim 1, characterized in that, The 200 specifically includes: S200.1 Configure a raw water collection system and set the raw water source; configure a multi-stage filtration and heating pretreatment process; configure an ultrafiltration membrane system and set the fine filtration path. Raw water delivery pipelines are deployed within the factory area to divert municipal tap water and mine drainage water to the clear water tank. The clear water tank serves as a unified water intake point and has functions of temporary storage and water volume balancing. The water effluent from the clear water tank is drawn by a chemical water supply pump and transported to the raw water heater. The chemical water supply pump is a centrifugal type with a rated flow of 60 cubic meters per hour, and two pumps are connected in parallel. The effluent from the clear water tank is pumped to the raw water heater via a chemical feed water pump. The raw water heater adopts a steam heat exchange tube bundle structure, and the effluent temperature ranges from 25℃ to 35℃. The heated water enters the dual-media filter group, which consists of four dual-media filters connected in parallel. Each dual-media filter has a built-in quartz sand filter layer and anthracite filter layer with a filter layer thickness of 1000 mm and a filtration accuracy of 5 microns to 10 microns. Each dual-media filter is equipped with a backwashing device, and the backwashing cycle is once every 24 hours. The effluent from the dual-media filter group enters the ultrafiltration unit group, which consists of four hollow fiber membrane ultrafiltration units connected in parallel. The membrane pore size is 0.01 microns, and the operation mode is cross-flow filtration. The transmembrane pressure difference is set between 0.1 MPa and 0.3 MPa. The ultrafiltration unit group is equipped with a chemical cleaning device with a cleaning cycle of 48 hours. The ultrafiltration permeate is stored in the ultrafiltration permeate tank and then transported to the first-stage reverse osmosis unit. S200.2 Configure the primary reverse osmosis system and set the reverse osmosis parameters; configure the secondary reverse osmosis system and set the low conductivity water treatment path. The ultrafiltration permeate is pressurized by the first-stage reverse osmosis booster pump and enters the first-stage reverse osmosis security filter, with a filtration accuracy of 5 microns. It then enters the first-stage reverse osmosis high-pressure pump, with a pressurization range of 1.5 MPa to 2.5 MPa, and is sent to the first-stage reverse osmosis unit. The first-stage reverse osmosis unit uses polyamide composite membrane modules with an average desalination rate of 98%. The permeate is stored in the first-stage reverse osmosis permeate tank. Part of it is sent to the heating network spray system, and part of it is used as feed water for the second-stage reverse osmosis unit. The concentrate is discharged into the sewage network and undergoes neutralization treatment. The primary reverse osmosis permeate is pressurized by the secondary reverse osmosis booster pump and enters the secondary reverse osmosis security filter with a filtration accuracy of 1 micron. Then it enters the secondary reverse osmosis high-pressure pump, with a pressurization range of 1.0 MPa to 1.8 MPa, and is sent to the secondary reverse osmosis unit. The secondary reverse osmosis unit uses a high desalination rate composite membrane module, and the permeate conductivity threshold is no higher than 10 microsiemens per centimeter. The permeate is stored in the secondary reverse osmosis permeate tank, mixed with the feed water of the ion exchanger, and the concentrate is partially returned to the clear water tank. S200.3 Configure a mixed ion exchanger, set the demineralized water output path, set a backup tank, and set the regulating capacity; The permeate from the secondary reverse osmosis is pumped to the mixed-bed ion exchanger via a mixed-bed feed pump. The mixed-bed ion exchanger uses a mixed-bed structure of anion exchange resin and cation exchange resin, with a resin layer height of not less than 1200 mm and an exchange capacity of not less than 1000 liter equivalents per cubic meter. It is equipped with an online conductivity monitoring device. When the conductivity exceeds 0.2 microsiemens per centimeter, the regeneration process is triggered. Regeneration uses alternating cleaning with dilute sulfuric acid and sodium hydroxide solution. The effluent enters the demineralized water tank, and the demineralized water is pumped to the main plant as boiler feedwater, heating network feedwater, and process spray water. The backup water treatment equipment includes a clarifier and a variable porosity filter. The clarifier has a volume of 150 cubic meters to achieve suspended solids sedimentation and water volume regulation. The variable porosity filter adopts an adjustable filtration rate structure with a filtration rate range of 8 to 12 meters per hour. Under special operating conditions, it can be switched to operate via valves as a pretreatment bypass.

4. The integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants according to claim 1, characterized in that, The 300 specifically includes: S300.1 Configure a sewage diversion system and set the sewage source category; configure a bar screen slag removal unit and set the interception path for large particulate impurities. A closed gravity drainage network system is deployed within the power plant area. The drainage network includes: boiler blowdown pipelines, chemical makeup water concentrate discharge pipelines, equipment flushing wastewater discharge ditches, and domestic sewage discharge ditches. The boiler blowdown pipe is specifically designed to collect boiler blowdown water discharged periodically from the boiler. The pipe is made of corrosion-resistant ceramic composite pipe with a diameter of DN80 and the joint adopts a high-temperature self-sealing structure. The chemical makeup water concentrate discharge pipe is specifically designed to collect concentrate from the reverse osmosis system. The pipe is made of fiberglass with a diameter of DN65 and a pressure resistance rating of PN10. The equipment flushing wastewater discharge channel and the domestic sewage discharge channel share a common mixed drainage channel. The surface of the channel is coated with alkali-resistant anti-corrosion material. Boiler blowdown pipes, chemical makeup water concentrate discharge pipes, equipment flushing wastewater discharge channels, and domestic sewage discharge channels all converge into a sewage collection well. The sewage collection well is made of reinforced concrete with an epoxy anti-corrosion coating on the inner wall and has a volume of 50 cubic meters. A liquid level detection float device is installed at the top of the sewage collection well. When the sewage level reaches 80% of the volume, the control cabinet is automatically triggered to start the lift pump. Two submersible sewage lift pumps are installed in the sewage collection well and operate in parallel. Each pump has a rated power of 7.5kW, a flow rate of 30 cubic meters per hour, and a head of 15 meters. The pump body is made of stainless steel, and the impeller has an anti-winding structure. The control system adopts a soft start mode. The sewage lift pump outlet is transported to the inlet of the mechanical bar screen slag removal equipment through a DN100 conveying pipe. Wastewater is pumped into the mechanical bar screen removal equipment via a lift pump. The mechanical bar screen removal equipment adopts a rotary chain structure and is made of 304 stainless steel. The bar spacing is 10 mm. Wastewater passes through the bar screen from bottom to top, and floating objects and large particles are intercepted. The mechanical grab rake is driven by a chain to periodically scrape the intercepted impurities to the top discharge hopper. The bottom of the discharge hopper is connected to a screw compactor. The screw compactor compacts the screen slag to a moisture content of less than 50%. The compacted screen slag is discharged into the screen slag box. The mechanical bar screen is set to run automatically twice per hour, with each run lasting 3 minutes. It also has a manual start mode. The effluent from the mechanical bar screen flows into the horizontal grit chamber by gravity. S300.2 Configure a grit chamber and set the sedimentation path for inorganic particles; configure a coagulation reaction tank and set the coagulation reaction parameters. The sedimentation tank adopts a horizontal rectangular structure, with a length of 8 meters, a width of 2.5 meters, a water depth of 2 meters, and a volume of 40 cubic meters. The designed hydraulic retention time is 25 to 30 minutes. A guide wall is installed at the inlet of the sedimentation tank to disperse the kinetic energy of the water and reduce short-circuiting. An overflow weir is installed at the outlet. The bottom of the grit chamber is designed with a longitudinal V-shaped slope of 1:5, which facilitates the sliding of sedimented sand particles to the sand collection trough in the center of the bottom of the chamber. The sand collection trough is 0.4 meters wide and equipped with a spiral sand conveyor at the bottom. The motor power of the sand conveyor is 1.5kW. The spiral sand conveyor transports the sedimented sand particles to the sand-water separator. The sand-water separator adopts a rotating spiral structure, with the main body made of carbon steel and lined with polyethylene. It reduces the moisture content of the sand particles to below 30%. The dewatered sand particles enter the solid waste collection area, and the effluent from the grit chamber enters the coagulation reaction tank through overflow. The coagulation reaction tank is divided into two parts: a rapid mixing tank and a slow flocculation tank. The rapid mixing tank has a volume of 3 cubic meters and is equipped with a vertical shaft high-speed agitator with a four-bladed folding impeller and a mixing speed of 100 rpm. The slow flocculation tank has a volume of 7 cubic meters and is equipped with a frame-type agitator with a mixing speed of 30 rpm. The coagulant dosing system includes: a storage tank, a metering pump, and a pipeline mixer. The storage tank has a volume of 1.5 cubic meters, the metering pump has a metering accuracy of ±1%, the coagulant is a liquid polyaluminum chloride solution, the dosing concentration is 100 to 150 mg / L, the dosing point is set at the inlet of the rapid mixing tank, and a transparent observation window is set at the top of the coagulation reaction tank to monitor the floc formation. After the coagulation reaction is completed, the water enters the dissolved air flotation device. S300.3 Configuring a dissolved air flotation device and setting the bubble floc separation path; The dissolved air flotation device is a rectangular horizontal flow flotation tank, 10 meters long, 3 meters wide, and 2.5 meters deep, with a volume of 75 cubic meters. The dissolved air system includes: a high-pressure dissolved air pump, a dissolved air tank, a microbubble releaser, and a return water pump. The high-pressure dissolved air pump operates at a pressure of 0.5 MPa, the dissolved air tank has an effective volume of 2 cubic meters, the microbubble releaser nozzle has a diameter of no more than 30 micrometers, and the return water pump has a flow rate of 5 cubic meters per hour. A return water pump draws a portion of the effluent from the flotation tank, pressurizes it, and sends it into the dissolved air tank, where the air is fully dissolved under high pressure. The dissolved air water then enters the flotation tank through a release device, forming microbubbles. These microbubbles combine with the coagulated flocs and float to the surface to form scum. The scum is scraped into the scum collection trough by a chain scraper and finally transported to the scum box by a conveyor belt. The effluent from the flotation tank flows into the deep biological treatment unit through an overflow weir.

5. The integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants according to claim 1, characterized in that, The 400 specifically includes: S400.1 Configure a contact oxidation tank and set up ammonia nitrogen and organic matter removal paths; configure a high-efficiency sedimentation tank and set up chemical phosphorus removal and solid-liquid separation paths. Wastewater treated by dissolved air flotation is introduced into a contact oxidation tank by gravity flow. The contact oxidation tank is a reinforced concrete structure with dimensions of 12 meters long, 4 meters wide, and 4 meters deep, and a total volume of 192 cubic meters. The hydraulic retention time is set to 8 hours. The contact oxidation tank is filled with three-dimensional elastic polyethylene packing material with a specific surface area of ​​not less than 350 square meters per cubic meter and a filling height of 3 meters for the growth of biofilm microorganisms. Liftable microporous aeration pipes are arranged at the bottom of the contact oxidation tank. The aeration pipes are connected to two Roots blowers through the air main pipe. Each Roots blower has an air volume of 50 cubic meters per minute and an air pressure of 58 kPa. The air main pipe is equipped with a swirl-type air volume regulating valve and a silencer. The bubble diameter of the microporous aeration head is not higher than 2 mm to maintain the dissolved oxygen conditions required for nitrification. The effluent from the contact oxidation tank enters the subsequent sedimentation structure through an overflow weir. The effluent from the contact oxidation tank enters the high-efficiency sedimentation tank, which adopts an inclined plate sedimentation structure. The tank dimensions are 10 meters long, 3 meters wide, and 3 meters deep. The inclined plate assembly is made of polypropylene, with an inclination angle of 60° and a spacing of 50 mm. The equivalent sedimentation area is 60 square meters. A chemical phosphorus removal dosing point is set on the inlet pipe of the high-efficiency sedimentation tank. The phosphorus removal agent is ferric chloride solution, with a concentration of 5% and a dosage of 1.2 liters per cubic meter of treated water. The dosing device consists of a 500-liter storage tank, a peristaltic metering pump with a metering accuracy of ±1%, and an electric regulating valve. After the dosing, iron phosphate flocs are formed in the inclined plate area and collected to the bottom of the tank along with the settled sludge. The sludge is discharged to the sludge temporary storage unit through the sludge discharge pipe at the bottom of the tank at regular intervals. The effluent from the high-efficiency sedimentation tank flows into the deep filtration unit through the effluent weir. The effluent turbidity control threshold is set to no higher than 3 NTU, and the total phosphorus concentration control threshold is set to no higher than 0.3 mg / L. S400.2 Configure a multi-media filter group, set the terminal interception path and operating parameters, configure the reuse water supply pipeline, and set the heating network makeup water and sprinkler makeup water paths. The effluent from the high-efficiency sedimentation tank enters the multi-media filter group, which consists of two vertical cylindrical filters connected in parallel. Each filter has a diameter of 1200 mm and a height of 2500 mm. Each multi-media filter is filled from bottom to top with a gravel support layer, a quartz sand layer, and an anthracite layer, with a total filter media height of 1.6 meters. The filter operation flow rate is set to 8 meters per hour, the working pressure is set to 0.3 MPa, each multi-media filter is equipped with an automatic backwashing program, the backwashing intensity is set to 12 liters per second per square meter, the backwashing time is set to 10 minutes, the backwashing start condition is that the inlet and outlet water pressure difference reaches 0.08 MPa or the running time reaches 48 hours, and the multi-media filter effluent suspended solids concentration control threshold is set to no more than 5 mg per liter; The effluent from the multi-media filter is proportionally distributed into the reuse water pipeline. The reuse water pipeline is made of stainless steel with a diameter of DN100 and an epoxy coating on the inner wall for corrosion protection. The delivery pressure is set at 0.25 MPa. The reuse water pipeline is equipped with an electromagnetic flow meter and a pressure transmitter for continuous collection of flow and pressure data. Electric regulating valves are installed in the heating network water supply branch and the spray water supply branch to achieve flow ratio control. A return bypass is set on the main pipe. The opening of the return bypass electric regulating valve is linked to the terminal pressure to maintain a stable delivery pressure when the water consumption at the end changes suddenly. The effluent that is not reused is introduced into the qualified water buffer tank. S400.3 Configuring online water quality monitoring devices and setting emission compliance confirmation thresholds; setting up continuous flue gas emission monitoring devices and setting monitoring paths for particulate matter and gaseous pollutants. The effluent from the multi-media filter that is not reused flows into the compliant water buffer tank. The compliant water buffer tank is a rectangular reinforced concrete tank with a volume of 50 cubic meters. It is equipped with a level gauge and a low-speed paddle agitator to prevent water stratification. An online water quality monitoring device is installed on the effluent pipeline of the compliant water buffer tank. The online water quality monitoring device includes a multi-parameter water quality analyzer, an automatic sampler, and a data acquisition and transmission module. The detection frequency is set to once every 15 minutes. The monitoring data is transmitted to the historical database of the distributed control system's data acquisition system via industrial Ethernet for retention and linkage judgment. The compliance judgment thresholds are set as follows: chemical oxygen demand not exceeding 50 mg / L, ammonia nitrogen not exceeding 5 mg / L, and total phosphorus not exceeding 0.5 mg / L. When the results of three consecutive tests meet the compliance judgment thresholds, the electric discharge valve of the compliant water buffer tank is opened, and the effluent is discharged into the municipal sewage pipe network. The high-temperature flue gas emitted by the gas turbine unit enters a vertical exhaust chimney after heat exchange in a waste heat boiler. The exhaust chimney is 60 meters high, with its inner wall coated with acid and alkali resistant anti-corrosion material. An exhaust diffusion cap is installed at the top, and a continuous emission monitoring device is installed at a height of 15 meters above the ground. The continuous emission monitoring device consists of a laser dust concentration detector, an ultraviolet differential absorption spectrometer, and a data recording module. The laser dust concentration detector is used to measure particulate matter concentration, the ultraviolet differential absorption spectrometer is used to measure sulfur dioxide and nitrogen oxide concentration, and the data recording module stores and uploads monitoring data at 1-minute intervals. The alarm thresholds for the continuous emission monitoring device are set as follows: particulate matter concentration 30 mg / m³, sulfur dioxide concentration 35 mg / m³, and nitrogen oxide concentration 50 mg / m³. When any indicator exceeds the corresponding alarm threshold, the data recording module sends a linkage load reduction control command to the distributed control system, and the gas turbine unit performs load reduction operation.

6. The integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants according to claim 1, characterized in that, The 500 specifically includes: S500.1 Configure the heating steam path and set the heat energy release logic for the three operating conditions of the steam turbine. Configure the heating network water supply path and set the start and stop logic for normal water supply and emergency water supply. During normal operation of the steam turbine, three heating steam paths are established in the steam power circuit according to the operating conditions of the steam turbine: the heating steam path for extraction and condensation conditions, the heating steam path for back pressure conditions, and the emergency heating steam path for full cut-off conditions. The switching of the heating steam path under condensing operation, back pressure operation, and emergency heating steam path under full-cut operation is jointly executed by the data acquisition system and the sequential control system of the distributed control system: the data acquisition system collects the heating network supply and return water temperature, heating network flow rate, steam pressure, and turbine load parameters; the sequential control system controls the opening degree of the medium and low pressure connecting pipe regulating valve, high pressure bypass electric valve, and medium pressure bypass electric valve according to the set switching conditions to achieve automatic selection and switching of the heating steam path; The heating network circulation loop is equipped with two water supply paths: a softened water supply path and an emergency water supply path from the Yellow River. The start and stop signals for the softened water replenishment path and the Yellow River emergency replenishment path are issued by the distributed control system based on the real-time data from the heating network pressure transmitter and the heating network flow meter. The opening degree of the replenishment regulating valve and the emergency replenishment valve is executed by the actuator of the digital electro-hydraulic control system. S500.2 Configure the heating network circulation equipment group and set the operating parameters of the heating circuit; configure the heating network return water purification unit and set the return water decontamination and reheating path. The equipment configuration of the heating network circuit includes: four heating network circulating water pumps, four tubular heaters, two condensate coolers, two constant pressure pumps, and one emergency water supply pump; Four horizontal single-stage centrifugal pumps are installed in the heating network circulating water system. Each pump has a rated flow of 100 cubic meters per hour, a head of 40 meters, and a motor power of 45 kilowatts. The suction inlets of the four pumps are connected to the main return water pipe of the heating network, and the outlets are connected to the main outlet water pipe of the heating network. Four tubular heaters are made of stainless steel heat exchange tubes. Each heater has a designed heat transfer area of ​​60 square meters. The four tubular heaters are connected in parallel between the main outlet water pipe of the heating network and the heating steam pipe for steam-circulating water heat exchange. Two condensate coolers are installed on the heating network steam condensate drain line. Each cooler has a heat exchange capacity of 0.8 megawatts. After the condensate cooler reaches the set temperature, it is discharged into the condensate header by the condensate pump. Two constant pressure pumps are installed on the constant pressure water supply branch. Each pump has a head of 25 meters and is used to maintain the constant pressure operation of the heating network circuit. One emergency water supply pump is installed upstream of the Yellow River emergency water supply path. The return water main of the heating network is equipped with a return water purification and return water reheating device: a return water decontamination device and a return water reheating device; The return water cleaning device consists of a fully automatic backwashing cleaner installed in series on the main return water pipe of the heating network. The cleaner has a filtration accuracy of 100 microns and a rated processing capacity of 120 cubic meters per hour. The differential pressure transmitter of the cleaner is set to a differential pressure threshold of 0.05 MPa. When the threshold is reached, the backwashing program is triggered by the electrical control system. The return water reheating device consists of two water-to-water heat exchangers installed in parallel on the branch line after the return water of the heating network is purified. The heat source for heat exchange is high-temperature condensate formed by the condensation of steam from the waste heat boiler. The heat transfer area of ​​a single water-to-water heat exchanger is 80 square meters. The opening of the valve on the heat exchange side is controlled by the electric actuator of the digital electro-hydraulic control system to stabilize the temperature of the return water entering the pump. The purified return water from the heating network is piped into the suction inlet of the heating network circulating water pump, forming a closed-loop circulation circuit. S500.3 Configure an air-cooled condensation circuit and set the iron ion filtration path and monitoring parameters; at the cold end of turbine No. 3, which adopts direct air cooling, set an air-cooled condensate and condensate iron removal unit, including: an air-cooled condensate pre-condensation pump and iron removal filter, and iron ion monitoring and backwashing. When the online monitoring value or verification value is higher than the control threshold, the sequential control system of the distributed control system sends a command to the backwash electric valve group of the iron removal filter to start the backwash program. The backwash duration is set to 8 minutes. At the same time as the backwash starts, the flow rate of the condensate pre-pump is reduced to stabilize the pipeline pressure.

7. The integrated process for the co-treatment and compliant discharge of industrial wastewater and domestic sewage from power plants according to claim 1, characterized in that, The 600 specifically includes: S600.1 Configure a boiler feedwater ammonia addition device and set the boiler feedwater pH adjustment path; configure a three-pressure boiler drum water sampling and monitoring device and set phosphate and pH control targets. Three sets of online ammonia dosing devices are installed on the low-pressure, medium-pressure, and high-pressure feedwater main pipes, respectively. Each set of online ammonia dosing devices consists of an ammonia storage tank, a metering pump, a dosing mixer, a dosing flow control valve, and a dosing pipeline. The mass fraction of the ammonia solution is set to 1%, and the metering pump has a metering accuracy of ±1%. A pH online monitoring instrument is installed on each of the three feedwater main pipes, and the pH online monitoring data is connected to the data acquisition system of the distributed control system. The digital electro-hydraulic control system adjusts the metering pump frequency in a closed loop based on the pH online monitoring data to control the pH value of the boiler feedwater between 9.5 and 9.8, and stops the addition of hydrazine deoxidizer. The pH value of the boiler feedwater is adjusted entirely by ammonia water. Automatic samplers, online pH monitors, online phosphate analyzers, online conductivity monitors, and data acquisition modules are installed at the high-pressure boiler water control targets, medium-pressure boiler water control targets, and low-pressure boiler water control targets, respectively. The monitoring data is written into the historical database of the distributed control system's data acquisition system at 10-minute intervals for linkage control and trend analysis. The control targets for the high-pressure boiler drum water are: phosphate concentration 0.5–2.0 mg / L; pH value 9.0–10.

0. Phosphate buffer and ammonia are added at the dosing point on the high-pressure feedwater main pipe. The phosphate dosage is controlled according to the online flow ratio. The control targets for the medium-pressure boiler drum water are: phosphate concentration 1.0–6.0 mg / L; pH value 9.0–10.

5. Phosphate and ammonia are added at the dosing point on the medium-pressure feedwater main pipe. The phosphate to ammonia dosage ratio is adjusted based on the online phosphate analysis results and the online pH monitoring results. The control targets for the low-pressure boiler drum water are: no phosphate buffer or solid alkalizing agent is added. Ammonia is continuously added at the ammonia addition point in the condensate circuit to adjust the pH value, which is generally controlled between 8.8 and 9.

3. S600.2 Configure the boiler water quality deviation identification formula, set the multi-parameter linkage control threshold, configure the redundancy of the dosing equipment and the online analysis calibration program, and set the operating boundary; A water quality deviation identification function is set in the high-pressure boiler water control to jointly determine the deviation between phosphate concentration and pH value; When ΔR>0.20, the data acquisition system of the distributed control system issues a trend deviation alarm signal and sends a dosing correction command to the digital electro-hydraulic control system. The multi-parameter linkage control threshold is set as follows: when the phosphate concentration decreases at a rate ≥10% / h for 60 consecutive minutes and the pH value decreases synchronously, the frequency of the phosphate metering pump is increased by 5% to 10%; when the pH value increases while the phosphate concentration decreases, it is determined that the ammonia dosage is too high and the frequency of the ammonia metering pump is reduced by 5% to 10%; when the conductivity increases by more than 15% of the monthly average and the dissolved oxygen concentration exceeds the process control line of 20 μg / L, supplementary sampling and manual testing are triggered, and the adjustment coefficients for phosphate and ammonia dosage are temporarily reduced by 5% each. All three sets of online ammonia dosing devices and three sets of phosphate dosing devices are equipped with a dual metering pump redundancy structure. The operating pump and the standby pump automatically rotate every 48 hours. The pH online monitor and the phosphate online analyzer are equipped with automatic cleaning and two-point calibration programs with a calibration cycle of 72 hours. The water quality exceeding the limit warning boundary is set to 95% of the upper and lower control limits: when the pH value or phosphate concentration reaches the corresponding warning boundary, the decentralized control system issues a warning and records the event. Manual testing and verification are conducted quarterly. Ion chromatography and potentiometric titration are used to compare online monitoring data, with an allowable deviation of ±5%. Both the dosing valve and the sampling valve are assigned unique identification numbers, which are then matched with the corresponding loops in the distributed control system screen.

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